| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Alex Tomas | 5553 | 20.42% | 6 | 1.37% |
| Theodore Y. Ts'o | 2715 | 9.98% | 79 | 18.08% |
| Lukas Czerner | 2142 | 7.88% | 26 | 5.95% |
| Eric Sandeen | 1971 | 7.25% | 7 | 1.60% |
| Dmitriy Monakhov | 1713 | 6.30% | 27 | 6.18% |
| Namjae Jeon | 1541 | 5.67% | 5 | 1.14% |
| Eric Whitney | 1270 | 4.67% | 20 | 4.58% |
| Harshad Shirwadkar | 1170 | 4.30% | 7 | 1.60% |
| Yongqiang Yang | 1077 | 3.96% | 13 | 2.97% |
| Dave Kleikamp | 866 | 3.18% | 2 | 0.46% |
| Amit Arora | 689 | 2.53% | 3 | 0.69% |
| Jan Kara | 657 | 2.42% | 27 | 6.18% |
| Aneesh Kumar K.V | 496 | 1.82% | 22 | 5.03% |
| Frank Mayhar | 471 | 1.73% | 2 | 0.46% |
| Ritesh Harjani | 466 | 1.71% | 8 | 1.83% |
| Darrick J. Wong | 440 | 1.62% | 7 | 1.60% |
| Mingming Cao | 391 | 1.44% | 12 | 2.75% |
| zhangyi (F) | 364 | 1.34% | 6 | 1.37% |
| Eric Gouriou | 329 | 1.21% | 2 | 0.46% |
| Zheng Liu | 323 | 1.19% | 17 | 3.89% |
| Christoph Hellwig | 267 | 0.98% | 6 | 1.37% |
| Aditya Kali | 236 | 0.87% | 3 | 0.69% |
| Allison Henderson | 207 | 0.76% | 6 | 1.37% |
| yangerkun | 180 | 0.66% | 5 | 1.14% |
| Ye Bin | 118 | 0.43% | 3 | 0.69% |
| Robin Dong | 115 | 0.42% | 6 | 1.37% |
| Sriram Rajagopalan | 113 | 0.42% | 1 | 0.23% |
| Eric Biggers | 111 | 0.41% | 7 | 1.60% |
| Avantika Mathur | 90 | 0.33% | 1 | 0.23% |
| Baokun Li | 84 | 0.31% | 5 | 1.14% |
| Forrest Liu | 81 | 0.30% | 1 | 0.23% |
| Ashish Sangwan | 60 | 0.22% | 2 | 0.46% |
| Eryu Guan | 58 | 0.21% | 3 | 0.69% |
| Jiaying Zhang | 57 | 0.21% | 4 | 0.92% |
| Shen Feng | 50 | 0.18% | 3 | 0.69% |
| Ross Zwisler | 47 | 0.17% | 1 | 0.23% |
| Xin Yin | 35 | 0.13% | 2 | 0.46% |
| Akira Fujita | 35 | 0.13% | 2 | 0.46% |
| Kazuya Mio | 32 | 0.12% | 1 | 0.23% |
| Jeff Layton | 28 | 0.10% | 2 | 0.46% |
| Luis Henriques | 28 | 0.10% | 1 | 0.23% |
| Gou Hao | 27 | 0.10% | 1 | 0.23% |
| Tao Ma | 25 | 0.09% | 6 | 1.37% |
| Michael Halcrow | 23 | 0.08% | 1 | 0.23% |
| Davide Italiano | 23 | 0.08% | 1 | 0.23% |
| Al Viro | 23 | 0.08% | 3 | 0.69% |
| Fabian Frederick | 22 | 0.08% | 3 | 0.69% |
| Vegard Nossum | 22 | 0.08% | 2 | 0.46% |
| Marcin Ślusarz | 21 | 0.08% | 1 | 0.23% |
| Randy Dunlap | 21 | 0.08% | 1 | 0.23% |
| Anirudh Rayabharam | 18 | 0.07% | 1 | 0.23% |
| Surbhi Palande | 18 | 0.07% | 1 | 0.23% |
| Kees Cook | 18 | 0.07% | 1 | 0.23% |
| Roman Peniaev | 17 | 0.06% | 2 | 0.46% |
| Nikolay Borisov | 17 | 0.06% | 2 | 0.46% |
| Solofo Ramangalahy | 15 | 0.06% | 1 | 0.23% |
| Kalpak Shah | 14 | 0.05% | 1 | 0.23% |
| Jiangshan Yi | 12 | 0.04% | 1 | 0.23% |
| Greg Harm | 10 | 0.04% | 1 | 0.23% |
| Dan Carpenter | 10 | 0.04% | 2 | 0.46% |
| Shilong Wang | 9 | 0.03% | 1 | 0.23% |
| Andreas Gruenbacher | 9 | 0.03% | 1 | 0.23% |
| liang xie | 9 | 0.03% | 1 | 0.23% |
| Curt Wohlgemuth | 9 | 0.03% | 2 | 0.46% |
| Amir Goldstein | 8 | 0.03% | 2 | 0.46% |
| Andi Kleen | 8 | 0.03% | 1 | 0.23% |
| Leonard Michlmayr | 8 | 0.03% | 1 | 0.23% |
| Nikanth Karthikesan | 8 | 0.03% | 1 | 0.23% |
| Suparna Bhattacharya | 8 | 0.03% | 1 | 0.23% |
| Tahsin Erdogan | 7 | 0.03% | 1 | 0.23% |
| Fengguang Wu | 6 | 0.02% | 1 | 0.23% |
| Li Xi | 6 | 0.02% | 1 | 0.23% |
| Akinobu Mita | 5 | 0.02% | 1 | 0.23% |
| Robert P. J. Day | 5 | 0.02% | 1 | 0.23% |
| Rakesh Pandit | 5 | 0.02% | 1 | 0.23% |
| zhanchengbin | 5 | 0.02% | 1 | 0.23% |
| Neil Brown | 4 | 0.01% | 1 | 0.23% |
| Hongnan Li | 4 | 0.01% | 1 | 0.23% |
| Maxim Patlasov | 4 | 0.01% | 1 | 0.23% |
| Wei Yongjun | 3 | 0.01% | 1 | 0.23% |
| Peter Hüwe | 3 | 0.01% | 1 | 0.23% |
| Nicholas Piggin | 3 | 0.01% | 1 | 0.23% |
| Ojaswin Mujoo | 3 | 0.01% | 1 | 0.23% |
| Keyur Patel | 3 | 0.01% | 1 | 0.23% |
| Cheng Nie | 2 | 0.01% | 1 | 0.23% |
| KeMeng Shi | 2 | 0.01% | 1 | 0.23% |
| Vivek Haldar | 2 | 0.01% | 1 | 0.23% |
| Tejun Heo | 2 | 0.01% | 1 | 0.23% |
| Anatol Pomozov | 1 | 0.00% | 1 | 0.23% |
| Paul Mackerras | 1 | 0.00% | 1 | 0.23% |
| David Moore | 1 | 0.00% | 1 | 0.23% |
| Christophe Jaillet | 1 | 0.00% | 1 | 0.23% |
| HaiboLiu | 1 | 0.00% | 1 | 0.23% |
| Chandan Rajendra | 1 | 0.00% | 1 | 0.23% |
| Jeffle Xu | 1 | 0.00% | 1 | 0.23% |
| zhengbin | 1 | 0.00% | 1 | 0.23% |
| Jakub Wilk | 1 | 0.00% | 1 | 0.23% |
| Linus Torvalds | 1 | 0.00% | 1 | 0.23% |
| Maninder Singh | 1 | 0.00% | 1 | 0.23% |
| Lucas De Marchi | 1 | 0.00% | 1 | 0.23% |
| Total | 27194 | 437 |
// SPDX-License-Identifier: GPL-2.0 /* * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com * Written by Alex Tomas <alex@clusterfs.com> * * Architecture independence: * Copyright (c) 2005, Bull S.A. * Written by Pierre Peiffer <pierre.peiffer@bull.net> */ /* * Extents support for EXT4 * * TODO: * - ext4*_error() should be used in some situations * - analyze all BUG()/BUG_ON(), use -EIO where appropriate * - smart tree reduction */ #include <linux/fs.h> #include <linux/time.h> #include <linux/jbd2.h> #include <linux/highuid.h> #include <linux/pagemap.h> #include <linux/quotaops.h> #include <linux/string.h> #include <linux/slab.h> #include <linux/uaccess.h> #include <linux/fiemap.h> #include <linux/iomap.h> #include <linux/sched/mm.h> #include "ext4_jbd2.h" #include "ext4_extents.h" #include "xattr.h" #include <trace/events/ext4.h> /* * used by extent splitting. */ #define EXT4_EXT_MAY_ZEROOUT 0x1 /* safe to zeroout if split fails \ due to ENOSPC */ #define EXT4_EXT_MARK_UNWRIT1 0x2 /* mark first half unwritten */ #define EXT4_EXT_MARK_UNWRIT2 0x4 /* mark second half unwritten */ #define EXT4_EXT_DATA_VALID1 0x8 /* first half contains valid data */ #define EXT4_EXT_DATA_VALID2 0x10 /* second half contains valid data */ static __le32 ext4_extent_block_csum(struct inode *inode, struct ext4_extent_header *eh) { struct ext4_inode_info *ei = EXT4_I(inode); struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); __u32 csum; csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)eh, EXT4_EXTENT_TAIL_OFFSET(eh)); return cpu_to_le32(csum); } static int ext4_extent_block_csum_verify(struct inode *inode, struct ext4_extent_header *eh) { struct ext4_extent_tail *et; if (!ext4_has_metadata_csum(inode->i_sb)) return 1; et = find_ext4_extent_tail(eh); if (et->et_checksum != ext4_extent_block_csum(inode, eh)) return 0; return 1; } static void ext4_extent_block_csum_set(struct inode *inode, struct ext4_extent_header *eh) { struct ext4_extent_tail *et; if (!ext4_has_metadata_csum(inode->i_sb)) return; et = find_ext4_extent_tail(eh); et->et_checksum = ext4_extent_block_csum(inode, eh); } static int ext4_split_extent_at(handle_t *handle, struct inode *inode, struct ext4_ext_path **ppath, ext4_lblk_t split, int split_flag, int flags); static int ext4_ext_trunc_restart_fn(struct inode *inode, int *dropped) { /* * Drop i_data_sem to avoid deadlock with ext4_map_blocks. At this * moment, get_block can be called only for blocks inside i_size since * page cache has been already dropped and writes are blocked by * i_rwsem. So we can safely drop the i_data_sem here. */ BUG_ON(EXT4_JOURNAL(inode) == NULL); ext4_discard_preallocations(inode); up_write(&EXT4_I(inode)->i_data_sem); *dropped = 1; return 0; } static void ext4_ext_drop_refs(struct ext4_ext_path *path) { int depth, i; if (!path) return; depth = path->p_depth; for (i = 0; i <= depth; i++, path++) { brelse(path->p_bh); path->p_bh = NULL; } } void ext4_free_ext_path(struct ext4_ext_path *path) { ext4_ext_drop_refs(path); kfree(path); } /* * Make sure 'handle' has at least 'check_cred' credits. If not, restart * transaction with 'restart_cred' credits. The function drops i_data_sem * when restarting transaction and gets it after transaction is restarted. * * The function returns 0 on success, 1 if transaction had to be restarted, * and < 0 in case of fatal error. */ int ext4_datasem_ensure_credits(handle_t *handle, struct inode *inode, int check_cred, int restart_cred, int revoke_cred) { int ret; int dropped = 0; ret = ext4_journal_ensure_credits_fn(handle, check_cred, restart_cred, revoke_cred, ext4_ext_trunc_restart_fn(inode, &dropped)); if (dropped) down_write(&EXT4_I(inode)->i_data_sem); return ret; } /* * could return: * - EROFS * - ENOMEM */ static int ext4_ext_get_access(handle_t *handle, struct inode *inode, struct ext4_ext_path *path) { int err = 0; if (path->p_bh) { /* path points to block */ BUFFER_TRACE(path->p_bh, "get_write_access"); err = ext4_journal_get_write_access(handle, inode->i_sb, path->p_bh, EXT4_JTR_NONE); /* * The extent buffer's verified bit will be set again in * __ext4_ext_dirty(). We could leave an inconsistent * buffer if the extents updating procudure break off du * to some error happens, force to check it again. */ if (!err) clear_buffer_verified(path->p_bh); } /* path points to leaf/index in inode body */ /* we use in-core data, no need to protect them */ return err; } /* * could return: * - EROFS * - ENOMEM * - EIO */ static int __ext4_ext_dirty(const char *where, unsigned int line, handle_t *handle, struct inode *inode, struct ext4_ext_path *path) { int err; WARN_ON(!rwsem_is_locked(&EXT4_I(inode)->i_data_sem)); if (path->p_bh) { ext4_extent_block_csum_set(inode, ext_block_hdr(path->p_bh)); /* path points to block */ err = __ext4_handle_dirty_metadata(where, line, handle, inode, path->p_bh); /* Extents updating done, re-set verified flag */ if (!err) set_buffer_verified(path->p_bh); } else { /* path points to leaf/index in inode body */ err = ext4_mark_inode_dirty(handle, inode); } return err; } #define ext4_ext_dirty(handle, inode, path) \ __ext4_ext_dirty(__func__, __LINE__, (handle), (inode), (path)) static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode, struct ext4_ext_path *path, ext4_lblk_t block) { if (path) { int depth = path->p_depth; struct ext4_extent *ex; /* * Try to predict block placement assuming that we are * filling in a file which will eventually be * non-sparse --- i.e., in the case of libbfd writing * an ELF object sections out-of-order but in a way * the eventually results in a contiguous object or * executable file, or some database extending a table * space file. However, this is actually somewhat * non-ideal if we are writing a sparse file such as * qemu or KVM writing a raw image file that is going * to stay fairly sparse, since it will end up * fragmenting the file system's free space. Maybe we * should have some hueristics or some way to allow * userspace to pass a hint to file system, * especially if the latter case turns out to be * common. */ ex = path[depth].p_ext; if (ex) { ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex); ext4_lblk_t ext_block = le32_to_cpu(ex->ee_block); if (block > ext_block) return ext_pblk + (block - ext_block); else return ext_pblk - (ext_block - block); } /* it looks like index is empty; * try to find starting block from index itself */ if (path[depth].p_bh) return path[depth].p_bh->b_blocknr; } /* OK. use inode's group */ return ext4_inode_to_goal_block(inode); } /* * Allocation for a meta data block */ static ext4_fsblk_t ext4_ext_new_meta_block(handle_t *handle, struct inode *inode, struct ext4_ext_path *path, struct ext4_extent *ex, int *err, unsigned int flags) { ext4_fsblk_t goal, newblock; goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block)); newblock = ext4_new_meta_blocks(handle, inode, goal, flags, NULL, err); return newblock; } static inline int ext4_ext_space_block(struct inode *inode, int check) { int size; size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) / sizeof(struct ext4_extent); #ifdef AGGRESSIVE_TEST if (!check && size > 6) size = 6; #endif return size; } static inline int ext4_ext_space_block_idx(struct inode *inode, int check) { int size; size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) / sizeof(struct ext4_extent_idx); #ifdef AGGRESSIVE_TEST if (!check && size > 5) size = 5; #endif return size; } static inline int ext4_ext_space_root(struct inode *inode, int check) { int size; size = sizeof(EXT4_I(inode)->i_data); size -= sizeof(struct ext4_extent_header); size /= sizeof(struct ext4_extent); #ifdef AGGRESSIVE_TEST if (!check && size > 3) size = 3; #endif return size; } static inline int ext4_ext_space_root_idx(struct inode *inode, int check) { int size; size = sizeof(EXT4_I(inode)->i_data); size -= sizeof(struct ext4_extent_header); size /= sizeof(struct ext4_extent_idx); #ifdef AGGRESSIVE_TEST if (!check && size > 4) size = 4; #endif return size; } static inline int ext4_force_split_extent_at(handle_t *handle, struct inode *inode, struct ext4_ext_path **ppath, ext4_lblk_t lblk, int nofail) { struct ext4_ext_path *path = *ppath; int unwritten = ext4_ext_is_unwritten(path[path->p_depth].p_ext); int flags = EXT4_EX_NOCACHE | EXT4_GET_BLOCKS_PRE_IO; if (nofail) flags |= EXT4_GET_BLOCKS_METADATA_NOFAIL | EXT4_EX_NOFAIL; return ext4_split_extent_at(handle, inode, ppath, lblk, unwritten ? EXT4_EXT_MARK_UNWRIT1|EXT4_EXT_MARK_UNWRIT2 : 0, flags); } static int ext4_ext_max_entries(struct inode *inode, int depth) { int max; if (depth == ext_depth(inode)) { if (depth == 0) max = ext4_ext_space_root(inode, 1); else max = ext4_ext_space_root_idx(inode, 1); } else { if (depth == 0) max = ext4_ext_space_block(inode, 1); else max = ext4_ext_space_block_idx(inode, 1); } return max; } static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext) { ext4_fsblk_t block = ext4_ext_pblock(ext); int len = ext4_ext_get_actual_len(ext); ext4_lblk_t lblock = le32_to_cpu(ext->ee_block); /* * We allow neither: * - zero length * - overflow/wrap-around */ if (lblock + len <= lblock) return 0; return ext4_inode_block_valid(inode, block, len); } static int ext4_valid_extent_idx(struct inode *inode, struct ext4_extent_idx *ext_idx) { ext4_fsblk_t block = ext4_idx_pblock(ext_idx); return ext4_inode_block_valid(inode, block, 1); } static int ext4_valid_extent_entries(struct inode *inode, struct ext4_extent_header *eh, ext4_lblk_t lblk, ext4_fsblk_t *pblk, int depth) { unsigned short entries; ext4_lblk_t lblock = 0; ext4_lblk_t cur = 0; if (eh->eh_entries == 0) return 1; entries = le16_to_cpu(eh->eh_entries); if (depth == 0) { /* leaf entries */ struct ext4_extent *ext = EXT_FIRST_EXTENT(eh); /* * The logical block in the first entry should equal to * the number in the index block. */ if (depth != ext_depth(inode) && lblk != le32_to_cpu(ext->ee_block)) return 0; while (entries) { if (!ext4_valid_extent(inode, ext)) return 0; /* Check for overlapping extents */ lblock = le32_to_cpu(ext->ee_block); if (lblock < cur) { *pblk = ext4_ext_pblock(ext); return 0; } cur = lblock + ext4_ext_get_actual_len(ext); ext++; entries--; } } else { struct ext4_extent_idx *ext_idx = EXT_FIRST_INDEX(eh); /* * The logical block in the first entry should equal to * the number in the parent index block. */ if (depth != ext_depth(inode) && lblk != le32_to_cpu(ext_idx->ei_block)) return 0; while (entries) { if (!ext4_valid_extent_idx(inode, ext_idx)) return 0; /* Check for overlapping index extents */ lblock = le32_to_cpu(ext_idx->ei_block); if (lblock < cur) { *pblk = ext4_idx_pblock(ext_idx); return 0; } ext_idx++; entries--; cur = lblock + 1; } } return 1; } static int __ext4_ext_check(const char *function, unsigned int line, struct inode *inode, struct ext4_extent_header *eh, int depth, ext4_fsblk_t pblk, ext4_lblk_t lblk) { const char *error_msg; int max = 0, err = -EFSCORRUPTED; if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) { error_msg = "invalid magic"; goto corrupted; } if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) { error_msg = "unexpected eh_depth"; goto corrupted; } if (unlikely(eh->eh_max == 0)) { error_msg = "invalid eh_max"; goto corrupted; } max = ext4_ext_max_entries(inode, depth); if (unlikely(le16_to_cpu(eh->eh_max) > max)) { error_msg = "too large eh_max"; goto corrupted; } if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) { error_msg = "invalid eh_entries"; goto corrupted; } if (unlikely((eh->eh_entries == 0) && (depth > 0))) { error_msg = "eh_entries is 0 but eh_depth is > 0"; goto corrupted; } if (!ext4_valid_extent_entries(inode, eh, lblk, &pblk, depth)) { error_msg = "invalid extent entries"; goto corrupted; } if (unlikely(depth > 32)) { error_msg = "too large eh_depth"; goto corrupted; } /* Verify checksum on non-root extent tree nodes */ if (ext_depth(inode) != depth && !ext4_extent_block_csum_verify(inode, eh)) { error_msg = "extent tree corrupted"; err = -EFSBADCRC; goto corrupted; } return 0; corrupted: ext4_error_inode_err(inode, function, line, 0, -err, "pblk %llu bad header/extent: %s - magic %x, " "entries %u, max %u(%u), depth %u(%u)", (unsigned long long) pblk, error_msg, le16_to_cpu(eh->eh_magic), le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max), max, le16_to_cpu(eh->eh_depth), depth); return err; } #define ext4_ext_check(inode, eh, depth, pblk) \ __ext4_ext_check(__func__, __LINE__, (inode), (eh), (depth), (pblk), 0) int ext4_ext_check_inode(struct inode *inode) { return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode), 0); } static void ext4_cache_extents(struct inode *inode, struct ext4_extent_header *eh) { struct ext4_extent *ex = EXT_FIRST_EXTENT(eh); ext4_lblk_t prev = 0; int i; for (i = le16_to_cpu(eh->eh_entries); i > 0; i--, ex++) { unsigned int status = EXTENT_STATUS_WRITTEN; ext4_lblk_t lblk = le32_to_cpu(ex->ee_block); int len = ext4_ext_get_actual_len(ex); if (prev && (prev != lblk)) ext4_es_cache_extent(inode, prev, lblk - prev, ~0, EXTENT_STATUS_HOLE); if (ext4_ext_is_unwritten(ex)) status = EXTENT_STATUS_UNWRITTEN; ext4_es_cache_extent(inode, lblk, len, ext4_ext_pblock(ex), status); prev = lblk + len; } } static struct buffer_head * __read_extent_tree_block(const char *function, unsigned int line, struct inode *inode, struct ext4_extent_idx *idx, int depth, int flags) { struct buffer_head *bh; int err; gfp_t gfp_flags = __GFP_MOVABLE | GFP_NOFS; ext4_fsblk_t pblk; if (flags & EXT4_EX_NOFAIL) gfp_flags |= __GFP_NOFAIL; pblk = ext4_idx_pblock(idx); bh = sb_getblk_gfp(inode->i_sb, pblk, gfp_flags); if (unlikely(!bh)) return ERR_PTR(-ENOMEM); if (!bh_uptodate_or_lock(bh)) { trace_ext4_ext_load_extent(inode, pblk, _RET_IP_); err = ext4_read_bh(bh, 0, NULL); if (err < 0) goto errout; } if (buffer_verified(bh) && !(flags & EXT4_EX_FORCE_CACHE)) return bh; err = __ext4_ext_check(function, line, inode, ext_block_hdr(bh), depth, pblk, le32_to_cpu(idx->ei_block)); if (err) goto errout; set_buffer_verified(bh); /* * If this is a leaf block, cache all of its entries */ if (!(flags & EXT4_EX_NOCACHE) && depth == 0) { struct ext4_extent_header *eh = ext_block_hdr(bh); ext4_cache_extents(inode, eh); } return bh; errout: put_bh(bh); return ERR_PTR(err); } #define read_extent_tree_block(inode, idx, depth, flags) \ __read_extent_tree_block(__func__, __LINE__, (inode), (idx), \ (depth), (flags)) /* * This function is called to cache a file's extent information in the * extent status tree */ int ext4_ext_precache(struct inode *inode) { struct ext4_inode_info *ei = EXT4_I(inode); struct ext4_ext_path *path = NULL; struct buffer_head *bh; int i = 0, depth, ret = 0; if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) return 0; /* not an extent-mapped inode */ down_read(&ei->i_data_sem); depth = ext_depth(inode); /* Don't cache anything if there are no external extent blocks */ if (!depth) { up_read(&ei->i_data_sem); return ret; } path = kcalloc(depth + 1, sizeof(struct ext4_ext_path), GFP_NOFS); if (path == NULL) { up_read(&ei->i_data_sem); return -ENOMEM; } path[0].p_hdr = ext_inode_hdr(inode); ret = ext4_ext_check(inode, path[0].p_hdr, depth, 0); if (ret) goto out; path[0].p_idx = EXT_FIRST_INDEX(path[0].p_hdr); while (i >= 0) { /* * If this is a leaf block or we've reached the end of * the index block, go up */ if ((i == depth) || path[i].p_idx > EXT_LAST_INDEX(path[i].p_hdr)) { brelse(path[i].p_bh); path[i].p_bh = NULL; i--; continue; } bh = read_extent_tree_block(inode, path[i].p_idx++, depth - i - 1, EXT4_EX_FORCE_CACHE); if (IS_ERR(bh)) { ret = PTR_ERR(bh); break; } i++; path[i].p_bh = bh; path[i].p_hdr = ext_block_hdr(bh); path[i].p_idx = EXT_FIRST_INDEX(path[i].p_hdr); } ext4_set_inode_state(inode, EXT4_STATE_EXT_PRECACHED); out: up_read(&ei->i_data_sem); ext4_free_ext_path(path); return ret; } #ifdef EXT_DEBUG static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path) { int k, l = path->p_depth; ext_debug(inode, "path:"); for (k = 0; k <= l; k++, path++) { if (path->p_idx) { ext_debug(inode, " %d->%llu", le32_to_cpu(path->p_idx->ei_block), ext4_idx_pblock(path->p_idx)); } else if (path->p_ext) { ext_debug(inode, " %d:[%d]%d:%llu ", le32_to_cpu(path->p_ext->ee_block), ext4_ext_is_unwritten(path->p_ext), ext4_ext_get_actual_len(path->p_ext), ext4_ext_pblock(path->p_ext)); } else ext_debug(inode, " []"); } ext_debug(inode, "\n"); } static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path) { int depth = ext_depth(inode); struct ext4_extent_header *eh; struct ext4_extent *ex; int i; if (!path) return; eh = path[depth].p_hdr; ex = EXT_FIRST_EXTENT(eh); ext_debug(inode, "Displaying leaf extents\n"); for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) { ext_debug(inode, "%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block), ext4_ext_is_unwritten(ex), ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex)); } ext_debug(inode, "\n"); } static void ext4_ext_show_move(struct inode *inode, struct ext4_ext_path *path, ext4_fsblk_t newblock, int level) { int depth = ext_depth(inode); struct ext4_extent *ex; if (depth != level) { struct ext4_extent_idx *idx; idx = path[level].p_idx; while (idx <= EXT_MAX_INDEX(path[level].p_hdr)) { ext_debug(inode, "%d: move %d:%llu in new index %llu\n", level, le32_to_cpu(idx->ei_block), ext4_idx_pblock(idx), newblock); idx++; } return; } ex = path[depth].p_ext; while (ex <= EXT_MAX_EXTENT(path[depth].p_hdr)) { ext_debug(inode, "move %d:%llu:[%d]%d in new leaf %llu\n", le32_to_cpu(ex->ee_block), ext4_ext_pblock(ex), ext4_ext_is_unwritten(ex), ext4_ext_get_actual_len(ex), newblock); ex++; } } #else #define ext4_ext_show_path(inode, path) #define ext4_ext_show_leaf(inode, path) #define ext4_ext_show_move(inode, path, newblock, level) #endif /* * ext4_ext_binsearch_idx: * binary search for the closest index of the given block * the header must be checked before calling this */ static void ext4_ext_binsearch_idx(struct inode *inode, struct ext4_ext_path *path, ext4_lblk_t block) { struct ext4_extent_header *eh = path->p_hdr; struct ext4_extent_idx *r, *l, *m; ext_debug(inode, "binsearch for %u(idx): ", block); l = EXT_FIRST_INDEX(eh) + 1; r = EXT_LAST_INDEX(eh); while (l <= r) { m = l + (r - l) / 2; ext_debug(inode, "%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block), m, le32_to_cpu(m->ei_block), r, le32_to_cpu(r->ei_block)); if (block < le32_to_cpu(m->ei_block)) r = m - 1; else l = m + 1; } path->p_idx = l - 1; ext_debug(inode, " -> %u->%lld ", le32_to_cpu(path->p_idx->ei_block), ext4_idx_pblock(path->p_idx)); #ifdef CHECK_BINSEARCH { struct ext4_extent_idx *chix, *ix; int k; chix = ix = EXT_FIRST_INDEX(eh); for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) { if (k != 0 && le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) { printk(KERN_DEBUG "k=%d, ix=0x%p, " "first=0x%p\n", k, ix, EXT_FIRST_INDEX(eh)); printk(KERN_DEBUG "%u <= %u\n", le32_to_cpu(ix->ei_block), le32_to_cpu(ix[-1].ei_block)); } BUG_ON(k && le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)); if (block < le32_to_cpu(ix->ei_block)) break; chix = ix; } BUG_ON(chix != path->p_idx); } #endif } /* * ext4_ext_binsearch: * binary search for closest extent of the given block * the header must be checked before calling this */ static void ext4_ext_binsearch(struct inode *inode, struct ext4_ext_path *path, ext4_lblk_t block) { struct ext4_extent_header *eh = path->p_hdr; struct ext4_extent *r, *l, *m; if (eh->eh_entries == 0) { /* * this leaf is empty: * we get such a leaf in split/add case */ return; } ext_debug(inode, "binsearch for %u: ", block); l = EXT_FIRST_EXTENT(eh) + 1; r = EXT_LAST_EXTENT(eh); while (l <= r) { m = l + (r - l) / 2; ext_debug(inode, "%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block), m, le32_to_cpu(m->ee_block), r, le32_to_cpu(r->ee_block)); if (block < le32_to_cpu(m->ee_block)) r = m - 1; else l = m + 1; } path->p_ext = l - 1; ext_debug(inode, " -> %d:%llu:[%d]%d ", le32_to_cpu(path->p_ext->ee_block), ext4_ext_pblock(path->p_ext), ext4_ext_is_unwritten(path->p_ext), ext4_ext_get_actual_len(path->p_ext)); #ifdef CHECK_BINSEARCH { struct ext4_extent *chex, *ex; int k; chex = ex = EXT_FIRST_EXTENT(eh); for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) { BUG_ON(k && le32_to_cpu(ex->ee_block) <= le32_to_cpu(ex[-1].ee_block)); if (block < le32_to_cpu(ex->ee_block)) break; chex = ex; } BUG_ON(chex != path->p_ext); } #endif } void ext4_ext_tree_init(handle_t *handle, struct inode *inode) { struct ext4_extent_header *eh; eh = ext_inode_hdr(inode); eh->eh_depth = 0; eh->eh_entries = 0; eh->eh_magic = EXT4_EXT_MAGIC; eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0)); eh->eh_generation = 0; ext4_mark_inode_dirty(handle, inode); } struct ext4_ext_path * ext4_find_extent(struct inode *inode, ext4_lblk_t block, struct ext4_ext_path **orig_path, int flags) { struct ext4_extent_header *eh; struct buffer_head *bh; struct ext4_ext_path *path = orig_path ? *orig_path : NULL; short int depth, i, ppos = 0; int ret; gfp_t gfp_flags = GFP_NOFS; if (flags & EXT4_EX_NOFAIL) gfp_flags |= __GFP_NOFAIL; eh = ext_inode_hdr(inode); depth = ext_depth(inode); if (depth < 0 || depth > EXT4_MAX_EXTENT_DEPTH) { EXT4_ERROR_INODE(inode, "inode has invalid extent depth: %d", depth); ret = -EFSCORRUPTED; goto err; } if (path) { ext4_ext_drop_refs(path); if (depth > path[0].p_maxdepth) { kfree(path); *orig_path = path = NULL; } } if (!path) { /* account possible depth increase */ path = kcalloc(depth + 2, sizeof(struct ext4_ext_path), gfp_flags); if (unlikely(!path)) return ERR_PTR(-ENOMEM); path[0].p_maxdepth = depth + 1; } path[0].p_hdr = eh; path[0].p_bh = NULL; i = depth; if (!(flags & EXT4_EX_NOCACHE) && depth == 0) ext4_cache_extents(inode, eh); /* walk through the tree */ while (i) { ext_debug(inode, "depth %d: num %d, max %d\n", ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max)); ext4_ext_binsearch_idx(inode, path + ppos, block); path[ppos].p_block = ext4_idx_pblock(path[ppos].p_idx); path[ppos].p_depth = i; path[ppos].p_ext = NULL; bh = read_extent_tree_block(inode, path[ppos].p_idx, --i, flags); if (IS_ERR(bh)) { ret = PTR_ERR(bh); goto err; } eh = ext_block_hdr(bh); ppos++; path[ppos].p_bh = bh; path[ppos].p_hdr = eh; } path[ppos].p_depth = i; path[ppos].p_ext = NULL; path[ppos].p_idx = NULL; /* find extent */ ext4_ext_binsearch(inode, path + ppos, block); /* if not an empty leaf */ if (path[ppos].p_ext) path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext); ext4_ext_show_path(inode, path); return path; err: ext4_free_ext_path(path); if (orig_path) *orig_path = NULL; return ERR_PTR(ret); } /* * ext4_ext_insert_index: * insert new index [@logical;@ptr] into the block at @curp; * check where to insert: before @curp or after @curp */ static int ext4_ext_insert_index(handle_t *handle, struct inode *inode, struct ext4_ext_path *curp, int logical, ext4_fsblk_t ptr) { struct ext4_extent_idx *ix; int len, err; err = ext4_ext_get_access(handle, inode, curp); if (err) return err; if (unlikely(logical == le32_to_cpu(curp->p_idx->ei_block))) { EXT4_ERROR_INODE(inode, "logical %d == ei_block %d!", logical, le32_to_cpu(curp->p_idx->ei_block)); return -EFSCORRUPTED; } if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries) >= le16_to_cpu(curp->p_hdr->eh_max))) { EXT4_ERROR_INODE(inode, "eh_entries %d >= eh_max %d!", le16_to_cpu(curp->p_hdr->eh_entries), le16_to_cpu(curp->p_hdr->eh_max)); return -EFSCORRUPTED; } if (logical > le32_to_cpu(curp->p_idx->ei_block)) { /* insert after */ ext_debug(inode, "insert new index %d after: %llu\n", logical, ptr); ix = curp->p_idx + 1; } else { /* insert before */ ext_debug(inode, "insert new index %d before: %llu\n", logical, ptr); ix = curp->p_idx; } if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) { EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!"); return -EFSCORRUPTED; } len = EXT_LAST_INDEX(curp->p_hdr) - ix + 1; BUG_ON(len < 0); if (len > 0) { ext_debug(inode, "insert new index %d: " "move %d indices from 0x%p to 0x%p\n", logical, len, ix, ix + 1); memmove(ix + 1, ix, len * sizeof(struct ext4_extent_idx)); } ix->ei_block = cpu_to_le32(logical); ext4_idx_store_pblock(ix, ptr); le16_add_cpu(&curp->p_hdr->eh_entries, 1); if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) { EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!"); return -EFSCORRUPTED; } err = ext4_ext_dirty(handle, inode, curp); ext4_std_error(inode->i_sb, err); return err; } /* * ext4_ext_split: * inserts new subtree into the path, using free index entry * at depth @at: * - allocates all needed blocks (new leaf and all intermediate index blocks) * - makes decision where to split * - moves remaining extents and index entries (right to the split point) * into the newly allocated blocks * - initializes subtree */ static int ext4_ext_split(handle_t *handle, struct inode *inode, unsigned int flags, struct ext4_ext_path *path, struct ext4_extent *newext, int at) { struct buffer_head *bh = NULL; int depth = ext_depth(inode); struct ext4_extent_header *neh; struct ext4_extent_idx *fidx; int i = at, k, m, a; ext4_fsblk_t newblock, oldblock; __le32 border; ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */ gfp_t gfp_flags = GFP_NOFS; int err = 0; size_t ext_size = 0; if (flags & EXT4_EX_NOFAIL) gfp_flags |= __GFP_NOFAIL; /* make decision: where to split? */ /* FIXME: now decision is simplest: at current extent */ /* if current leaf will be split, then we should use * border from split point */ if (unlikely(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr))) { EXT4_ERROR_INODE(inode, "p_ext > EXT_MAX_EXTENT!"); return -EFSCORRUPTED; } if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) { border = path[depth].p_ext[1].ee_block; ext_debug(inode, "leaf will be split." " next leaf starts at %d\n", le32_to_cpu(border)); } else { border = newext->ee_block; ext_debug(inode, "leaf will be added." " next leaf starts at %d\n", le32_to_cpu(border)); } /* * If error occurs, then we break processing * and mark filesystem read-only. index won't * be inserted and tree will be in consistent * state. Next mount will repair buffers too. */ /* * Get array to track all allocated blocks. * We need this to handle errors and free blocks * upon them. */ ablocks = kcalloc(depth, sizeof(ext4_fsblk_t), gfp_flags); if (!ablocks) return -ENOMEM; /* allocate all needed blocks */ ext_debug(inode, "allocate %d blocks for indexes/leaf\n", depth - at); for (a = 0; a < depth - at; a++) { newblock = ext4_ext_new_meta_block(handle, inode, path, newext, &err, flags); if (newblock == 0) goto cleanup; ablocks[a] = newblock; } /* initialize new leaf */ newblock = ablocks[--a]; if (unlikely(newblock == 0)) { EXT4_ERROR_INODE(inode, "newblock == 0!"); err = -EFSCORRUPTED; goto cleanup; } bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS); if (unlikely(!bh)) { err = -ENOMEM; goto cleanup; } lock_buffer(bh); err = ext4_journal_get_create_access(handle, inode->i_sb, bh, EXT4_JTR_NONE); if (err) goto cleanup; neh = ext_block_hdr(bh); neh->eh_entries = 0; neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0)); neh->eh_magic = EXT4_EXT_MAGIC; neh->eh_depth = 0; neh->eh_generation = 0; /* move remainder of path[depth] to the new leaf */ if (unlikely(path[depth].p_hdr->eh_entries != path[depth].p_hdr->eh_max)) { EXT4_ERROR_INODE(inode, "eh_entries %d != eh_max %d!", path[depth].p_hdr->eh_entries, path[depth].p_hdr->eh_max); err = -EFSCORRUPTED; goto cleanup; } /* start copy from next extent */ m = EXT_MAX_EXTENT(path[depth].p_hdr) - path[depth].p_ext++; ext4_ext_show_move(inode, path, newblock, depth); if (m) { struct ext4_extent *ex; ex = EXT_FIRST_EXTENT(neh); memmove(ex, path[depth].p_ext, sizeof(struct ext4_extent) * m); le16_add_cpu(&neh->eh_entries, m); } /* zero out unused area in the extent block */ ext_size = sizeof(struct ext4_extent_header) + sizeof(struct ext4_extent) * le16_to_cpu(neh->eh_entries); memset(bh->b_data + ext_size, 0, inode->i_sb->s_blocksize - ext_size); ext4_extent_block_csum_set(inode, neh); set_buffer_uptodate(bh); unlock_buffer(bh); err = ext4_handle_dirty_metadata(handle, inode, bh); if (err) goto cleanup; brelse(bh); bh = NULL; /* correct old leaf */ if (m) { err = ext4_ext_get_access(handle, inode, path + depth); if (err) goto cleanup; le16_add_cpu(&path[depth].p_hdr->eh_entries, -m); err = ext4_ext_dirty(handle, inode, path + depth); if (err) goto cleanup; } /* create intermediate indexes */ k = depth - at - 1; if (unlikely(k < 0)) { EXT4_ERROR_INODE(inode, "k %d < 0!", k); err = -EFSCORRUPTED; goto cleanup; } if (k) ext_debug(inode, "create %d intermediate indices\n", k); /* insert new index into current index block */ /* current depth stored in i var */ i = depth - 1; while (k--) { oldblock = newblock; newblock = ablocks[--a]; bh = sb_getblk(inode->i_sb, newblock); if (unlikely(!bh)) { err = -ENOMEM; goto cleanup; } lock_buffer(bh); err = ext4_journal_get_create_access(handle, inode->i_sb, bh, EXT4_JTR_NONE); if (err) goto cleanup; neh = ext_block_hdr(bh); neh->eh_entries = cpu_to_le16(1); neh->eh_magic = EXT4_EXT_MAGIC; neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0)); neh->eh_depth = cpu_to_le16(depth - i); neh->eh_generation = 0; fidx = EXT_FIRST_INDEX(neh); fidx->ei_block = border; ext4_idx_store_pblock(fidx, oldblock); ext_debug(inode, "int.index at %d (block %llu): %u -> %llu\n", i, newblock, le32_to_cpu(border), oldblock); /* move remainder of path[i] to the new index block */ if (unlikely(EXT_MAX_INDEX(path[i].p_hdr) != EXT_LAST_INDEX(path[i].p_hdr))) { EXT4_ERROR_INODE(inode, "EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!", le32_to_cpu(path[i].p_ext->ee_block)); err = -EFSCORRUPTED; goto cleanup; } /* start copy indexes */ m = EXT_MAX_INDEX(path[i].p_hdr) - path[i].p_idx++; ext_debug(inode, "cur 0x%p, last 0x%p\n", path[i].p_idx, EXT_MAX_INDEX(path[i].p_hdr)); ext4_ext_show_move(inode, path, newblock, i); if (m) { memmove(++fidx, path[i].p_idx, sizeof(struct ext4_extent_idx) * m); le16_add_cpu(&neh->eh_entries, m); } /* zero out unused area in the extent block */ ext_size = sizeof(struct ext4_extent_header) + (sizeof(struct ext4_extent) * le16_to_cpu(neh->eh_entries)); memset(bh->b_data + ext_size, 0, inode->i_sb->s_blocksize - ext_size); ext4_extent_block_csum_set(inode, neh); set_buffer_uptodate(bh); unlock_buffer(bh); err = ext4_handle_dirty_metadata(handle, inode, bh); if (err) goto cleanup; brelse(bh); bh = NULL; /* correct old index */ if (m) { err = ext4_ext_get_access(handle, inode, path + i); if (err) goto cleanup; le16_add_cpu(&path[i].p_hdr->eh_entries, -m); err = ext4_ext_dirty(handle, inode, path + i); if (err) goto cleanup; } i--; } /* insert new index */ err = ext4_ext_insert_index(handle, inode, path + at, le32_to_cpu(border), newblock); cleanup: if (bh) { if (buffer_locked(bh)) unlock_buffer(bh); brelse(bh); } if (err) { /* free all allocated blocks in error case */ for (i = 0; i < depth; i++) { if (!ablocks[i]) continue; ext4_free_blocks(handle, inode, NULL, ablocks[i], 1, EXT4_FREE_BLOCKS_METADATA); } } kfree(ablocks); return err; } /* * ext4_ext_grow_indepth: * implements tree growing procedure: * - allocates new block * - moves top-level data (index block or leaf) into the new block * - initializes new top-level, creating index that points to the * just created block */ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode, unsigned int flags) { struct ext4_extent_header *neh; struct buffer_head *bh; ext4_fsblk_t newblock, goal = 0; struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es; int err = 0; size_t ext_size = 0; /* Try to prepend new index to old one */ if (ext_depth(inode)) goal = ext4_idx_pblock(EXT_FIRST_INDEX(ext_inode_hdr(inode))); if (goal > le32_to_cpu(es->s_first_data_block)) { flags |= EXT4_MB_HINT_TRY_GOAL; goal--; } else goal = ext4_inode_to_goal_block(inode); newblock = ext4_new_meta_blocks(handle, inode, goal, flags, NULL, &err); if (newblock == 0) return err; bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS); if (unlikely(!bh)) return -ENOMEM; lock_buffer(bh); err = ext4_journal_get_create_access(handle, inode->i_sb, bh, EXT4_JTR_NONE); if (err) { unlock_buffer(bh); goto out; } ext_size = sizeof(EXT4_I(inode)->i_data); /* move top-level index/leaf into new block */ memmove(bh->b_data, EXT4_I(inode)->i_data, ext_size); /* zero out unused area in the extent block */ memset(bh->b_data + ext_size, 0, inode->i_sb->s_blocksize - ext_size); /* set size of new block */ neh = ext_block_hdr(bh); /* old root could have indexes or leaves * so calculate e_max right way */ if (ext_depth(inode)) neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0)); else neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0)); neh->eh_magic = EXT4_EXT_MAGIC; ext4_extent_block_csum_set(inode, neh); set_buffer_uptodate(bh); set_buffer_verified(bh); unlock_buffer(bh); err = ext4_handle_dirty_metadata(handle, inode, bh); if (err) goto out; /* Update top-level index: num,max,pointer */ neh = ext_inode_hdr(inode); neh->eh_entries = cpu_to_le16(1); ext4_idx_store_pblock(EXT_FIRST_INDEX(neh), newblock); if (neh->eh_depth == 0) { /* Root extent block becomes index block */ neh->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0)); EXT_FIRST_INDEX(neh)->ei_block = EXT_FIRST_EXTENT(neh)->ee_block; } ext_debug(inode, "new root: num %d(%d), lblock %d, ptr %llu\n", le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max), le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block), ext4_idx_pblock(EXT_FIRST_INDEX(neh))); le16_add_cpu(&neh->eh_depth, 1); err = ext4_mark_inode_dirty(handle, inode); out: brelse(bh); return err; } /* * ext4_ext_create_new_leaf: * finds empty index and adds new leaf. * if no free index is found, then it requests in-depth growing. */ static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode, unsigned int mb_flags, unsigned int gb_flags, struct ext4_ext_path **ppath, struct ext4_extent *newext) { struct ext4_ext_path *path = *ppath; struct ext4_ext_path *curp; int depth, i, err = 0; repeat: i = depth = ext_depth(inode); /* walk up to the tree and look for free index entry */ curp = path + depth; while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) { i--; curp--; } /* we use already allocated block for index block, * so subsequent data blocks should be contiguous */ if (EXT_HAS_FREE_INDEX(curp)) { /* if we found index with free entry, then use that * entry: create all needed subtree and add new leaf */ err = ext4_ext_split(handle, inode, mb_flags, path, newext, i); if (err) goto out; /* refill path */ path = ext4_find_extent(inode, (ext4_lblk_t)le32_to_cpu(newext->ee_block), ppath, gb_flags); if (IS_ERR(path)) err = PTR_ERR(path); } else { /* tree is full, time to grow in depth */ err = ext4_ext_grow_indepth(handle, inode, mb_flags); if (err) goto out; /* refill path */ path = ext4_find_extent(inode, (ext4_lblk_t)le32_to_cpu(newext->ee_block), ppath, gb_flags); if (IS_ERR(path)) { err = PTR_ERR(path); goto out; } /* * only first (depth 0 -> 1) produces free space; * in all other cases we have to split the grown tree */ depth = ext_depth(inode); if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) { /* now we need to split */ goto repeat; } } out: return err; } /* * search the closest allocated block to the left for *logical * and returns it at @logical + it's physical address at @phys * if *logical is the smallest allocated block, the function * returns 0 at @phys * return value contains 0 (success) or error code */ static int ext4_ext_search_left(struct inode *inode, struct ext4_ext_path *path, ext4_lblk_t *logical, ext4_fsblk_t *phys) { struct ext4_extent_idx *ix; struct ext4_extent *ex; int depth, ee_len; if (unlikely(path == NULL)) { EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical); return -EFSCORRUPTED; } depth = path->p_depth; *phys = 0; if (depth == 0 && path->p_ext == NULL) return 0; /* usually extent in the path covers blocks smaller * then *logical, but it can be that extent is the * first one in the file */ ex = path[depth].p_ext; ee_len = ext4_ext_get_actual_len(ex); if (*logical < le32_to_cpu(ex->ee_block)) { if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) { EXT4_ERROR_INODE(inode, "EXT_FIRST_EXTENT != ex *logical %d ee_block %d!", *logical, le32_to_cpu(ex->ee_block)); return -EFSCORRUPTED; } while (--depth >= 0) { ix = path[depth].p_idx; if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) { EXT4_ERROR_INODE(inode, "ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!", ix != NULL ? le32_to_cpu(ix->ei_block) : 0, le32_to_cpu(EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block), depth); return -EFSCORRUPTED; } } return 0; } if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) { EXT4_ERROR_INODE(inode, "logical %d < ee_block %d + ee_len %d!", *logical, le32_to_cpu(ex->ee_block), ee_len); return -EFSCORRUPTED; } *logical = le32_to_cpu(ex->ee_block) + ee_len - 1; *phys = ext4_ext_pblock(ex) + ee_len - 1; return 0; } /* * Search the closest allocated block to the right for *logical * and returns it at @logical + it's physical address at @phys. * If not exists, return 0 and @phys is set to 0. We will return * 1 which means we found an allocated block and ret_ex is valid. * Or return a (< 0) error code. */ static int ext4_ext_search_right(struct inode *inode, struct ext4_ext_path *path, ext4_lblk_t *logical, ext4_fsblk_t *phys, struct ext4_extent *ret_ex) { struct buffer_head *bh = NULL; struct ext4_extent_header *eh; struct ext4_extent_idx *ix; struct ext4_extent *ex; int depth; /* Note, NOT eh_depth; depth from top of tree */ int ee_len; if (unlikely(path == NULL)) { EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical); return -EFSCORRUPTED; } depth = path->p_depth; *phys = 0; if (depth == 0 && path->p_ext == NULL) return 0; /* usually extent in the path covers blocks smaller * then *logical, but it can be that extent is the * first one in the file */ ex = path[depth].p_ext; ee_len = ext4_ext_get_actual_len(ex); if (*logical < le32_to_cpu(ex->ee_block)) { if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) { EXT4_ERROR_INODE(inode, "first_extent(path[%d].p_hdr) != ex", depth); return -EFSCORRUPTED; } while (--depth >= 0) { ix = path[depth].p_idx; if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) { EXT4_ERROR_INODE(inode, "ix != EXT_FIRST_INDEX *logical %d!", *logical); return -EFSCORRUPTED; } } goto found_extent; } if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) { EXT4_ERROR_INODE(inode, "logical %d < ee_block %d + ee_len %d!", *logical, le32_to_cpu(ex->ee_block), ee_len); return -EFSCORRUPTED; } if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) { /* next allocated block in this leaf */ ex++; goto found_extent; } /* go up and search for index to the right */ while (--depth >= 0) { ix = path[depth].p_idx; if (ix != EXT_LAST_INDEX(path[depth].p_hdr)) goto got_index; } /* we've gone up to the root and found no index to the right */ return 0; got_index: /* we've found index to the right, let's * follow it and find the closest allocated * block to the right */ ix++; while (++depth < path->p_depth) { /* subtract from p_depth to get proper eh_depth */ bh = read_extent_tree_block(inode, ix, path->p_depth - depth, 0); if (IS_ERR(bh)) return PTR_ERR(bh); eh = ext_block_hdr(bh); ix = EXT_FIRST_INDEX(eh); put_bh(bh); } bh = read_extent_tree_block(inode, ix, path->p_depth - depth, 0); if (IS_ERR(bh)) return PTR_ERR(bh); eh = ext_block_hdr(bh); ex = EXT_FIRST_EXTENT(eh); found_extent: *logical = le32_to_cpu(ex->ee_block); *phys = ext4_ext_pblock(ex); if (ret_ex) *ret_ex = *ex; if (bh) put_bh(bh); return 1; } /* * ext4_ext_next_allocated_block: * returns allocated block in subsequent extent or EXT_MAX_BLOCKS. * NOTE: it considers block number from index entry as * allocated block. Thus, index entries have to be consistent * with leaves. */ ext4_lblk_t ext4_ext_next_allocated_block(struct ext4_ext_path *path) { int depth; BUG_ON(path == NULL); depth = path->p_depth; if (depth == 0 && path->p_ext == NULL) return EXT_MAX_BLOCKS; while (depth >= 0) { struct ext4_ext_path *p = &path[depth]; if (depth == path->p_depth) { /* leaf */ if (p->p_ext && p->p_ext != EXT_LAST_EXTENT(p->p_hdr)) return le32_to_cpu(p->p_ext[1].ee_block); } else { /* index */ if (p->p_idx != EXT_LAST_INDEX(p->p_hdr)) return le32_to_cpu(p->p_idx[1].ei_block); } depth--; } return EXT_MAX_BLOCKS; } /* * ext4_ext_next_leaf_block: * returns first allocated block from next leaf or EXT_MAX_BLOCKS */ static ext4_lblk_t ext4_ext_next_leaf_block(struct ext4_ext_path *path) { int depth; BUG_ON(path == NULL); depth = path->p_depth; /* zero-tree has no leaf blocks at all */ if (depth == 0) return EXT_MAX_BLOCKS; /* go to index block */ depth--; while (depth >= 0) { if (path[depth].p_idx != EXT_LAST_INDEX(path[depth].p_hdr)) return (ext4_lblk_t) le32_to_cpu(path[depth].p_idx[1].ei_block); depth--; } return EXT_MAX_BLOCKS; } /* * ext4_ext_correct_indexes: * if leaf gets modified and modified extent is first in the leaf, * then we have to correct all indexes above. * TODO: do we need to correct tree in all cases? */ static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode, struct ext4_ext_path *path) { struct ext4_extent_header *eh; int depth = ext_depth(inode); struct ext4_extent *ex; __le32 border; int k, err = 0; eh = path[depth].p_hdr; ex = path[depth].p_ext; if (unlikely(ex == NULL || eh == NULL)) { EXT4_ERROR_INODE(inode, "ex %p == NULL or eh %p == NULL", ex, eh); return -EFSCORRUPTED; } if (depth == 0) { /* there is no tree at all */ return 0; } if (ex != EXT_FIRST_EXTENT(eh)) { /* we correct tree if first leaf got modified only */ return 0; } /* * TODO: we need correction if border is smaller than current one */ k = depth - 1; border = path[depth].p_ext->ee_block; err = ext4_ext_get_access(handle, inode, path + k); if (err) return err; path[k].p_idx->ei_block = border; err = ext4_ext_dirty(handle, inode, path + k); if (err) return err; while (k--) { /* change all left-side indexes */ if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr)) break; err = ext4_ext_get_access(handle, inode, path + k); if (err) break; path[k].p_idx->ei_block = border; err = ext4_ext_dirty(handle, inode, path + k); if (err) break; } return err; } static int ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1, struct ext4_extent *ex2) { unsigned short ext1_ee_len, ext2_ee_len; if (ext4_ext_is_unwritten(ex1) != ext4_ext_is_unwritten(ex2)) return 0; ext1_ee_len = ext4_ext_get_actual_len(ex1); ext2_ee_len = ext4_ext_get_actual_len(ex2); if (le32_to_cpu(ex1->ee_block) + ext1_ee_len != le32_to_cpu(ex2->ee_block)) return 0; if (ext1_ee_len + ext2_ee_len > EXT_INIT_MAX_LEN) return 0; if (ext4_ext_is_unwritten(ex1) && ext1_ee_len + ext2_ee_len > EXT_UNWRITTEN_MAX_LEN) return 0; #ifdef AGGRESSIVE_TEST if (ext1_ee_len >= 4) return 0; #endif if (ext4_ext_pblock(ex1) + ext1_ee_len == ext4_ext_pblock(ex2)) return 1; return 0; } /* * This function tries to merge the "ex" extent to the next extent in the tree. * It always tries to merge towards right. If you want to merge towards * left, pass "ex - 1" as argument instead of "ex". * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns * 1 if they got merged. */ static int ext4_ext_try_to_merge_right(struct inode *inode, struct ext4_ext_path *path, struct ext4_extent *ex) { struct ext4_extent_header *eh; unsigned int depth, len; int merge_done = 0, unwritten; depth = ext_depth(inode); BUG_ON(path[depth].p_hdr == NULL); eh = path[depth].p_hdr; while (ex < EXT_LAST_EXTENT(eh)) { if (!ext4_can_extents_be_merged(inode, ex, ex + 1)) break; /* merge with next extent! */ unwritten = ext4_ext_is_unwritten(ex); ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex) + ext4_ext_get_actual_len(ex + 1)); if (unwritten) ext4_ext_mark_unwritten(ex); if (ex + 1 < EXT_LAST_EXTENT(eh)) { len = (EXT_LAST_EXTENT(eh) - ex - 1) * sizeof(struct ext4_extent); memmove(ex + 1, ex + 2, len); } le16_add_cpu(&eh->eh_entries, -1); merge_done = 1; WARN_ON(eh->eh_entries == 0); if (!eh->eh_entries) EXT4_ERROR_INODE(inode, "eh->eh_entries = 0!"); } return merge_done; } /* * This function does a very simple check to see if we can collapse * an extent tree with a single extent tree leaf block into the inode. */ static void ext4_ext_try_to_merge_up(handle_t *handle, struct inode *inode, struct ext4_ext_path *path) { size_t s; unsigned max_root = ext4_ext_space_root(inode, 0); ext4_fsblk_t blk; if ((path[0].p_depth != 1) || (le16_to_cpu(path[0].p_hdr->eh_entries) != 1) || (le16_to_cpu(path[1].p_hdr->eh_entries) > max_root)) return; /* * We need to modify the block allocation bitmap and the block * group descriptor to release the extent tree block. If we * can't get the journal credits, give up. */ if (ext4_journal_extend(handle, 2, ext4_free_metadata_revoke_credits(inode->i_sb, 1))) return; /* * Copy the extent data up to the inode */ blk = ext4_idx_pblock(path[0].p_idx); s = le16_to_cpu(path[1].p_hdr->eh_entries) * sizeof(struct ext4_extent_idx); s += sizeof(struct ext4_extent_header); path[1].p_maxdepth = path[0].p_maxdepth; memcpy(path[0].p_hdr, path[1].p_hdr, s); path[0].p_depth = 0; path[0].p_ext = EXT_FIRST_EXTENT(path[0].p_hdr) + (path[1].p_ext - EXT_FIRST_EXTENT(path[1].p_hdr)); path[0].p_hdr->eh_max = cpu_to_le16(max_root); brelse(path[1].p_bh); ext4_free_blocks(handle, inode, NULL, blk, 1, EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET); } /* * This function tries to merge the @ex extent to neighbours in the tree, then * tries to collapse the extent tree into the inode. */ static void ext4_ext_try_to_merge(handle_t *handle, struct inode *inode, struct ext4_ext_path *path, struct ext4_extent *ex) { struct ext4_extent_header *eh; unsigned int depth; int merge_done = 0; depth = ext_depth(inode); BUG_ON(path[depth].p_hdr == NULL); eh = path[depth].p_hdr; if (ex > EXT_FIRST_EXTENT(eh)) merge_done = ext4_ext_try_to_merge_right(inode, path, ex - 1); if (!merge_done) (void) ext4_ext_try_to_merge_right(inode, path, ex); ext4_ext_try_to_merge_up(handle, inode, path); } /* * check if a portion of the "newext" extent overlaps with an * existing extent. * * If there is an overlap discovered, it updates the length of the newext * such that there will be no overlap, and then returns 1. * If there is no overlap found, it returns 0. */ static unsigned int ext4_ext_check_overlap(struct ext4_sb_info *sbi, struct inode *inode, struct ext4_extent *newext, struct ext4_ext_path *path) { ext4_lblk_t b1, b2; unsigned int depth, len1; unsigned int ret = 0; b1 = le32_to_cpu(newext->ee_block); len1 = ext4_ext_get_actual_len(newext); depth = ext_depth(inode); if (!path[depth].p_ext) goto out; b2 = EXT4_LBLK_CMASK(sbi, le32_to_cpu(path[depth].p_ext->ee_block)); /* * get the next allocated block if the extent in the path * is before the requested block(s) */ if (b2 < b1) { b2 = ext4_ext_next_allocated_block(path); if (b2 == EXT_MAX_BLOCKS) goto out; b2 = EXT4_LBLK_CMASK(sbi, b2); } /* check for wrap through zero on extent logical start block*/ if (b1 + len1 < b1) { len1 = EXT_MAX_BLOCKS - b1; newext->ee_len = cpu_to_le16(len1); ret = 1; } /* check for overlap */ if (b1 + len1 > b2) { newext->ee_len = cpu_to_le16(b2 - b1); ret = 1; } out: return ret; } /* * ext4_ext_insert_extent: * tries to merge requested extent into the existing extent or * inserts requested extent as new one into the tree, * creating new leaf in the no-space case. */ int ext4_ext_insert_extent(handle_t *handle, struct inode *inode, struct ext4_ext_path **ppath, struct ext4_extent *newext, int gb_flags) { struct ext4_ext_path *path = *ppath; struct ext4_extent_header *eh; struct ext4_extent *ex, *fex; struct ext4_extent *nearex; /* nearest extent */ struct ext4_ext_path *npath = NULL; int depth, len, err; ext4_lblk_t next; int mb_flags = 0, unwritten; if (gb_flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) mb_flags |= EXT4_MB_DELALLOC_RESERVED; if (unlikely(ext4_ext_get_actual_len(newext) == 0)) { EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0"); return -EFSCORRUPTED; } depth = ext_depth(inode); ex = path[depth].p_ext; eh = path[depth].p_hdr; if (unlikely(path[depth].p_hdr == NULL)) { EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth); return -EFSCORRUPTED; } /* try to insert block into found extent and return */ if (ex && !(gb_flags & EXT4_GET_BLOCKS_PRE_IO)) { /* * Try to see whether we should rather test the extent on * right from ex, or from the left of ex. This is because * ext4_find_extent() can return either extent on the * left, or on the right from the searched position. This * will make merging more effective. */ if (ex < EXT_LAST_EXTENT(eh) && (le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex) < le32_to_cpu(newext->ee_block))) { ex += 1; goto prepend; } else if ((ex > EXT_FIRST_EXTENT(eh)) && (le32_to_cpu(newext->ee_block) + ext4_ext_get_actual_len(newext) < le32_to_cpu(ex->ee_block))) ex -= 1; /* Try to append newex to the ex */ if (ext4_can_extents_be_merged(inode, ex, newext)) { ext_debug(inode, "append [%d]%d block to %u:[%d]%d" "(from %llu)\n", ext4_ext_is_unwritten(newext), ext4_ext_get_actual_len(newext), le32_to_cpu(ex->ee_block), ext4_ext_is_unwritten(ex), ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex)); err = ext4_ext_get_access(handle, inode, path + depth); if (err) return err; unwritten = ext4_ext_is_unwritten(ex); ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex) + ext4_ext_get_actual_len(newext)); if (unwritten) ext4_ext_mark_unwritten(ex); nearex = ex; goto merge; } prepend: /* Try to prepend newex to the ex */ if (ext4_can_extents_be_merged(inode, newext, ex)) { ext_debug(inode, "prepend %u[%d]%d block to %u:[%d]%d" "(from %llu)\n", le32_to_cpu(newext->ee_block), ext4_ext_is_unwritten(newext), ext4_ext_get_actual_len(newext), le32_to_cpu(ex->ee_block), ext4_ext_is_unwritten(ex), ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex)); err = ext4_ext_get_access(handle, inode, path + depth); if (err) return err; unwritten = ext4_ext_is_unwritten(ex); ex->ee_block = newext->ee_block; ext4_ext_store_pblock(ex, ext4_ext_pblock(newext)); ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex) + ext4_ext_get_actual_len(newext)); if (unwritten) ext4_ext_mark_unwritten(ex); nearex = ex; goto merge; } } depth = ext_depth(inode); eh = path[depth].p_hdr; if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) goto has_space; /* probably next leaf has space for us? */ fex = EXT_LAST_EXTENT(eh); next = EXT_MAX_BLOCKS; if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block)) next = ext4_ext_next_leaf_block(path); if (next != EXT_MAX_BLOCKS) { ext_debug(inode, "next leaf block - %u\n", next); BUG_ON(npath != NULL); npath = ext4_find_extent(inode, next, NULL, gb_flags); if (IS_ERR(npath)) return PTR_ERR(npath); BUG_ON(npath->p_depth != path->p_depth); eh = npath[depth].p_hdr; if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) { ext_debug(inode, "next leaf isn't full(%d)\n", le16_to_cpu(eh->eh_entries)); path = npath; goto has_space; } ext_debug(inode, "next leaf has no free space(%d,%d)\n", le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max)); } /* * There is no free space in the found leaf. * We're gonna add a new leaf in the tree. */ if (gb_flags & EXT4_GET_BLOCKS_METADATA_NOFAIL) mb_flags |= EXT4_MB_USE_RESERVED; err = ext4_ext_create_new_leaf(handle, inode, mb_flags, gb_flags, ppath, newext); if (err) goto cleanup; depth = ext_depth(inode); eh = path[depth].p_hdr; has_space: nearex = path[depth].p_ext; err = ext4_ext_get_access(handle, inode, path + depth); if (err) goto cleanup; if (!nearex) { /* there is no extent in this leaf, create first one */ ext_debug(inode, "first extent in the leaf: %u:%llu:[%d]%d\n", le32_to_cpu(newext->ee_block), ext4_ext_pblock(newext), ext4_ext_is_unwritten(newext), ext4_ext_get_actual_len(newext)); nearex = EXT_FIRST_EXTENT(eh); } else { if (le32_to_cpu(newext->ee_block) > le32_to_cpu(nearex->ee_block)) { /* Insert after */ ext_debug(inode, "insert %u:%llu:[%d]%d before: " "nearest %p\n", le32_to_cpu(newext->ee_block), ext4_ext_pblock(newext), ext4_ext_is_unwritten(newext), ext4_ext_get_actual_len(newext), nearex); nearex++; } else { /* Insert before */ BUG_ON(newext->ee_block == nearex->ee_block); ext_debug(inode, "insert %u:%llu:[%d]%d after: " "nearest %p\n", le32_to_cpu(newext->ee_block), ext4_ext_pblock(newext), ext4_ext_is_unwritten(newext), ext4_ext_get_actual_len(newext), nearex); } len = EXT_LAST_EXTENT(eh) - nearex + 1; if (len > 0) { ext_debug(inode, "insert %u:%llu:[%d]%d: " "move %d extents from 0x%p to 0x%p\n", le32_to_cpu(newext->ee_block), ext4_ext_pblock(newext), ext4_ext_is_unwritten(newext), ext4_ext_get_actual_len(newext), len, nearex, nearex + 1); memmove(nearex + 1, nearex, len * sizeof(struct ext4_extent)); } } le16_add_cpu(&eh->eh_entries, 1); path[depth].p_ext = nearex; nearex->ee_block = newext->ee_block; ext4_ext_store_pblock(nearex, ext4_ext_pblock(newext)); nearex->ee_len = newext->ee_len; merge: /* try to merge extents */ if (!(gb_flags & EXT4_GET_BLOCKS_PRE_IO)) ext4_ext_try_to_merge(handle, inode, path, nearex); /* time to correct all indexes above */ err = ext4_ext_correct_indexes(handle, inode, path); if (err) goto cleanup; err = ext4_ext_dirty(handle, inode, path + path->p_depth); cleanup: ext4_free_ext_path(npath); return err; } static int ext4_fill_es_cache_info(struct inode *inode, ext4_lblk_t block, ext4_lblk_t num, struct fiemap_extent_info *fieinfo) { ext4_lblk_t next, end = block + num - 1; struct extent_status es; unsigned char blksize_bits = inode->i_sb->s_blocksize_bits; unsigned int flags; int err; while (block <= end) { next = 0; flags = 0; if (!ext4_es_lookup_extent(inode, block, &next, &es)) break; if (ext4_es_is_unwritten(&es)) flags |= FIEMAP_EXTENT_UNWRITTEN; if (ext4_es_is_delayed(&es)) flags |= (FIEMAP_EXTENT_DELALLOC | FIEMAP_EXTENT_UNKNOWN); if (ext4_es_is_hole(&es)) flags |= EXT4_FIEMAP_EXTENT_HOLE; if (next == 0) flags |= FIEMAP_EXTENT_LAST; if (flags & (FIEMAP_EXTENT_DELALLOC| EXT4_FIEMAP_EXTENT_HOLE)) es.es_pblk = 0; else es.es_pblk = ext4_es_pblock(&es); err = fiemap_fill_next_extent(fieinfo, (__u64)es.es_lblk << blksize_bits, (__u64)es.es_pblk << blksize_bits, (__u64)es.es_len << blksize_bits, flags); if (next == 0) break; block = next; if (err < 0) return err; if (err == 1) return 0; } return 0; } /* * ext4_ext_find_hole - find hole around given block according to the given path * @inode: inode we lookup in * @path: path in extent tree to @lblk * @lblk: pointer to logical block around which we want to determine hole * * Determine hole length (and start if easily possible) around given logical * block. We don't try too hard to find the beginning of the hole but @path * actually points to extent before @lblk, we provide it. * * The function returns the length of a hole starting at @lblk. We update @lblk * to the beginning of the hole if we managed to find it. */ static ext4_lblk_t ext4_ext_find_hole(struct inode *inode, struct ext4_ext_path *path, ext4_lblk_t *lblk) { int depth = ext_depth(inode); struct ext4_extent *ex; ext4_lblk_t len; ex = path[depth].p_ext; if (ex == NULL) { /* there is no extent yet, so gap is [0;-] */ *lblk = 0; len = EXT_MAX_BLOCKS; } else if (*lblk < le32_to_cpu(ex->ee_block)) { len = le32_to_cpu(ex->ee_block) - *lblk; } else if (*lblk >= le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex)) { ext4_lblk_t next; *lblk = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex); next = ext4_ext_next_allocated_block(path); BUG_ON(next == *lblk); len = next - *lblk; } else { BUG(); } return len; } /* * ext4_ext_rm_idx: * removes index from the index block. */ static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode, struct ext4_ext_path *path, int depth) { int err; ext4_fsblk_t leaf; /* free index block */ depth--; path = path + depth; leaf = ext4_idx_pblock(path->p_idx); if (unlikely(path->p_hdr->eh_entries == 0)) { EXT4_ERROR_INODE(inode, "path->p_hdr->eh_entries == 0"); return -EFSCORRUPTED; } err = ext4_ext_get_access(handle, inode, path); if (err) return err; if (path->p_idx != EXT_LAST_INDEX(path->p_hdr)) { int len = EXT_LAST_INDEX(path->p_hdr) - path->p_idx; len *= sizeof(struct ext4_extent_idx); memmove(path->p_idx, path->p_idx + 1, len); } le16_add_cpu(&path->p_hdr->eh_entries, -1); err = ext4_ext_dirty(handle, inode, path); if (err) return err; ext_debug(inode, "index is empty, remove it, free block %llu\n", leaf); trace_ext4_ext_rm_idx(inode, leaf); ext4_free_blocks(handle, inode, NULL, leaf, 1, EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET); while (--depth >= 0) { if (path->p_idx != EXT_FIRST_INDEX(path->p_hdr)) break; path--; err = ext4_ext_get_access(handle, inode, path); if (err) break; path->p_idx->ei_block = (path+1)->p_idx->ei_block; err = ext4_ext_dirty(handle, inode, path); if (err) break; } return err; } /* * ext4_ext_calc_credits_for_single_extent: * This routine returns max. credits that needed to insert an extent * to the extent tree. * When pass the actual path, the caller should calculate credits * under i_data_sem. */ int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks, struct ext4_ext_path *path) { if (path) { int depth = ext_depth(inode); int ret = 0; /* probably there is space in leaf? */ if (le16_to_cpu(path[depth].p_hdr->eh_entries) < le16_to_cpu(path[depth].p_hdr->eh_max)) { /* * There are some space in the leaf tree, no * need to account for leaf block credit * * bitmaps and block group descriptor blocks * and other metadata blocks still need to be * accounted. */ /* 1 bitmap, 1 block group descriptor */ ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb); return ret; } } return ext4_chunk_trans_blocks(inode, nrblocks); } /* * How many index/leaf blocks need to change/allocate to add @extents extents? * * If we add a single extent, then in the worse case, each tree level * index/leaf need to be changed in case of the tree split. * * If more extents are inserted, they could cause the whole tree split more * than once, but this is really rare. */ int ext4_ext_index_trans_blocks(struct inode *inode, int extents) { int index; int depth; /* If we are converting the inline data, only one is needed here. */ if (ext4_has_inline_data(inode)) return 1; depth = ext_depth(inode); if (extents <= 1) index = depth * 2; else index = depth * 3; return index; } static inline int get_default_free_blocks_flags(struct inode *inode) { if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode) || ext4_test_inode_flag(inode, EXT4_INODE_EA_INODE)) return EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET; else if (ext4_should_journal_data(inode)) return EXT4_FREE_BLOCKS_FORGET; return 0; } /* * ext4_rereserve_cluster - increment the reserved cluster count when * freeing a cluster with a pending reservation * * @inode - file containing the cluster * @lblk - logical block in cluster to be reserved * * Increments the reserved cluster count and adjusts quota in a bigalloc * file system when freeing a partial cluster containing at least one * delayed and unwritten block. A partial cluster meeting that * requirement will have a pending reservation. If so, the * RERESERVE_CLUSTER flag is used when calling ext4_free_blocks() to * defer reserved and allocated space accounting to a subsequent call * to this function. */ static void ext4_rereserve_cluster(struct inode *inode, ext4_lblk_t lblk) { struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); struct ext4_inode_info *ei = EXT4_I(inode); dquot_reclaim_block(inode, EXT4_C2B(sbi, 1)); spin_lock(&ei->i_block_reservation_lock); ei->i_reserved_data_blocks++; percpu_counter_add(&sbi->s_dirtyclusters_counter, 1); spin_unlock(&ei->i_block_reservation_lock); percpu_counter_add(&sbi->s_freeclusters_counter, 1); ext4_remove_pending(inode, lblk); } static int ext4_remove_blocks(handle_t *handle, struct inode *inode, struct ext4_extent *ex, struct partial_cluster *partial, ext4_lblk_t from, ext4_lblk_t to) { struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); unsigned short ee_len = ext4_ext_get_actual_len(ex); ext4_fsblk_t last_pblk, pblk; ext4_lblk_t num; int flags; /* only extent tail removal is allowed */ if (from < le32_to_cpu(ex->ee_block) || to != le32_to_cpu(ex->ee_block) + ee_len - 1) { ext4_error(sbi->s_sb, "strange request: removal(2) %u-%u from %u:%u", from, to, le32_to_cpu(ex->ee_block), ee_len); return 0; } #ifdef EXTENTS_STATS spin_lock(&sbi->s_ext_stats_lock); sbi->s_ext_blocks += ee_len; sbi->s_ext_extents++; if (ee_len < sbi->s_ext_min) sbi->s_ext_min = ee_len; if (ee_len > sbi->s_ext_max) sbi->s_ext_max = ee_len; if (ext_depth(inode) > sbi->s_depth_max) sbi->s_depth_max = ext_depth(inode); spin_unlock(&sbi->s_ext_stats_lock); #endif trace_ext4_remove_blocks(inode, ex, from, to, partial); /* * if we have a partial cluster, and it's different from the * cluster of the last block in the extent, we free it */ last_pblk = ext4_ext_pblock(ex) + ee_len - 1; if (partial->state != initial && partial->pclu != EXT4_B2C(sbi, last_pblk)) { if (partial->state == tofree) { flags = get_default_free_blocks_flags(inode); if (ext4_is_pending(inode, partial->lblk)) flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER; ext4_free_blocks(handle, inode, NULL, EXT4_C2B(sbi, partial->pclu), sbi->s_cluster_ratio, flags); if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER) ext4_rereserve_cluster(inode, partial->lblk); } partial->state = initial; } num = le32_to_cpu(ex->ee_block) + ee_len - from; pblk = ext4_ext_pblock(ex) + ee_len - num; /* * We free the partial cluster at the end of the extent (if any), * unless the cluster is used by another extent (partial_cluster * state is nofree). If a partial cluster exists here, it must be * shared with the last block in the extent. */ flags = get_default_free_blocks_flags(inode); /* partial, left end cluster aligned, right end unaligned */ if ((EXT4_LBLK_COFF(sbi, to) != sbi->s_cluster_ratio - 1) && (EXT4_LBLK_CMASK(sbi, to) >= from) && (partial->state != nofree)) { if (ext4_is_pending(inode, to)) flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER; ext4_free_blocks(handle, inode, NULL, EXT4_PBLK_CMASK(sbi, last_pblk), sbi->s_cluster_ratio, flags); if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER) ext4_rereserve_cluster(inode, to); partial->state = initial; flags = get_default_free_blocks_flags(inode); } flags |= EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER; /* * For bigalloc file systems, we never free a partial cluster * at the beginning of the extent. Instead, we check to see if we * need to free it on a subsequent call to ext4_remove_blocks, * or at the end of ext4_ext_rm_leaf or ext4_ext_remove_space. */ flags |= EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER; ext4_free_blocks(handle, inode, NULL, pblk, num, flags); /* reset the partial cluster if we've freed past it */ if (partial->state != initial && partial->pclu != EXT4_B2C(sbi, pblk)) partial->state = initial; /* * If we've freed the entire extent but the beginning is not left * cluster aligned and is not marked as ineligible for freeing we * record the partial cluster at the beginning of the extent. It * wasn't freed by the preceding ext4_free_blocks() call, and we * need to look farther to the left to determine if it's to be freed * (not shared with another extent). Else, reset the partial * cluster - we're either done freeing or the beginning of the * extent is left cluster aligned. */ if (EXT4_LBLK_COFF(sbi, from) && num == ee_len) { if (partial->state == initial) { partial->pclu = EXT4_B2C(sbi, pblk); partial->lblk = from; partial->state = tofree; } } else { partial->state = initial; } return 0; } /* * ext4_ext_rm_leaf() Removes the extents associated with the * blocks appearing between "start" and "end". Both "start" * and "end" must appear in the same extent or EIO is returned. * * @handle: The journal handle * @inode: The files inode * @path: The path to the leaf * @partial_cluster: The cluster which we'll have to free if all extents * has been released from it. However, if this value is * negative, it's a cluster just to the right of the * punched region and it must not be freed. * @start: The first block to remove * @end: The last block to remove */ static int ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, struct ext4_ext_path *path, struct partial_cluster *partial, ext4_lblk_t start, ext4_lblk_t end) { struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); int err = 0, correct_index = 0; int depth = ext_depth(inode), credits, revoke_credits; struct ext4_extent_header *eh; ext4_lblk_t a, b; unsigned num; ext4_lblk_t ex_ee_block; unsigned short ex_ee_len; unsigned unwritten = 0; struct ext4_extent *ex; ext4_fsblk_t pblk; /* the header must be checked already in ext4_ext_remove_space() */ ext_debug(inode, "truncate since %u in leaf to %u\n", start, end); if (!path[depth].p_hdr) path[depth].p_hdr = ext_block_hdr(path[depth].p_bh); eh = path[depth].p_hdr; if (unlikely(path[depth].p_hdr == NULL)) { EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth); return -EFSCORRUPTED; } /* find where to start removing */ ex = path[depth].p_ext; if (!ex) ex = EXT_LAST_EXTENT(eh); ex_ee_block = le32_to_cpu(ex->ee_block); ex_ee_len = ext4_ext_get_actual_len(ex); trace_ext4_ext_rm_leaf(inode, start, ex, partial); while (ex >= EXT_FIRST_EXTENT(eh) && ex_ee_block + ex_ee_len > start) { if (ext4_ext_is_unwritten(ex)) unwritten = 1; else unwritten = 0; ext_debug(inode, "remove ext %u:[%d]%d\n", ex_ee_block, unwritten, ex_ee_len); path[depth].p_ext = ex; a = max(ex_ee_block, start); b = min(ex_ee_block + ex_ee_len - 1, end); ext_debug(inode, " border %u:%u\n", a, b); /* If this extent is beyond the end of the hole, skip it */ if (end < ex_ee_block) { /* * We're going to skip this extent and move to another, * so note that its first cluster is in use to avoid * freeing it when removing blocks. Eventually, the * right edge of the truncated/punched region will * be just to the left. */ if (sbi->s_cluster_ratio > 1) { pblk = ext4_ext_pblock(ex); partial->pclu = EXT4_B2C(sbi, pblk); partial->state = nofree; } ex--; ex_ee_block = le32_to_cpu(ex->ee_block); ex_ee_len = ext4_ext_get_actual_len(ex); continue; } else if (b != ex_ee_block + ex_ee_len - 1) { EXT4_ERROR_INODE(inode, "can not handle truncate %u:%u " "on extent %u:%u", start, end, ex_ee_block, ex_ee_block + ex_ee_len - 1); err = -EFSCORRUPTED; goto out; } else if (a != ex_ee_block) { /* remove tail of the extent */ num = a - ex_ee_block; } else { /* remove whole extent: excellent! */ num = 0; } /* * 3 for leaf, sb, and inode plus 2 (bmap and group * descriptor) for each block group; assume two block * groups plus ex_ee_len/blocks_per_block_group for * the worst case */ credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb)); if (ex == EXT_FIRST_EXTENT(eh)) { correct_index = 1; credits += (ext_depth(inode)) + 1; } credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb); /* * We may end up freeing some index blocks and data from the * punched range. Note that partial clusters are accounted for * by ext4_free_data_revoke_credits(). */ revoke_credits = ext4_free_metadata_revoke_credits(inode->i_sb, ext_depth(inode)) + ext4_free_data_revoke_credits(inode, b - a + 1); err = ext4_datasem_ensure_credits(handle, inode, credits, credits, revoke_credits); if (err) { if (err > 0) err = -EAGAIN; goto out; } err = ext4_ext_get_access(handle, inode, path + depth); if (err) goto out; err = ext4_remove_blocks(handle, inode, ex, partial, a, b); if (err) goto out; if (num == 0) /* this extent is removed; mark slot entirely unused */ ext4_ext_store_pblock(ex, 0); ex->ee_len = cpu_to_le16(num); /* * Do not mark unwritten if all the blocks in the * extent have been removed. */ if (unwritten && num) ext4_ext_mark_unwritten(ex); /* * If the extent was completely released, * we need to remove it from the leaf */ if (num == 0) { if (end != EXT_MAX_BLOCKS - 1) { /* * For hole punching, we need to scoot all the * extents up when an extent is removed so that * we dont have blank extents in the middle */ memmove(ex, ex+1, (EXT_LAST_EXTENT(eh) - ex) * sizeof(struct ext4_extent)); /* Now get rid of the one at the end */ memset(EXT_LAST_EXTENT(eh), 0, sizeof(struct ext4_extent)); } le16_add_cpu(&eh->eh_entries, -1); } err = ext4_ext_dirty(handle, inode, path + depth); if (err) goto out; ext_debug(inode, "new extent: %u:%u:%llu\n", ex_ee_block, num, ext4_ext_pblock(ex)); ex--; ex_ee_block = le32_to_cpu(ex->ee_block); ex_ee_len = ext4_ext_get_actual_len(ex); } if (correct_index && eh->eh_entries) err = ext4_ext_correct_indexes(handle, inode, path); /* * If there's a partial cluster and at least one extent remains in * the leaf, free the partial cluster if it isn't shared with the * current extent. If it is shared with the current extent * we reset the partial cluster because we've reached the start of the * truncated/punched region and we're done removing blocks. */ if (partial->state == tofree && ex >= EXT_FIRST_EXTENT(eh)) { pblk = ext4_ext_pblock(ex) + ex_ee_len - 1; if (partial->pclu != EXT4_B2C(sbi, pblk)) { int flags = get_default_free_blocks_flags(inode); if (ext4_is_pending(inode, partial->lblk)) flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER; ext4_free_blocks(handle, inode, NULL, EXT4_C2B(sbi, partial->pclu), sbi->s_cluster_ratio, flags); if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER) ext4_rereserve_cluster(inode, partial->lblk); } partial->state = initial; } /* if this leaf is free, then we should * remove it from index block above */ if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL) err = ext4_ext_rm_idx(handle, inode, path, depth); out: return err; } /* * ext4_ext_more_to_rm: * returns 1 if current index has to be freed (even partial) */ static int ext4_ext_more_to_rm(struct ext4_ext_path *path) { BUG_ON(path->p_idx == NULL); if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr)) return 0; /* * if truncate on deeper level happened, it wasn't partial, * so we have to consider current index for truncation */ if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block) return 0; return 1; } int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start, ext4_lblk_t end) { struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); int depth = ext_depth(inode); struct ext4_ext_path *path = NULL; struct partial_cluster partial; handle_t *handle; int i = 0, err = 0; partial.pclu = 0; partial.lblk = 0; partial.state = initial; ext_debug(inode, "truncate since %u to %u\n", start, end); /* probably first extent we're gonna free will be last in block */ handle = ext4_journal_start_with_revoke(inode, EXT4_HT_TRUNCATE, depth + 1, ext4_free_metadata_revoke_credits(inode->i_sb, depth)); if (IS_ERR(handle)) return PTR_ERR(handle); again: trace_ext4_ext_remove_space(inode, start, end, depth); /* * Check if we are removing extents inside the extent tree. If that * is the case, we are going to punch a hole inside the extent tree * so we have to check whether we need to split the extent covering * the last block to remove so we can easily remove the part of it * in ext4_ext_rm_leaf(). */ if (end < EXT_MAX_BLOCKS - 1) { struct ext4_extent *ex; ext4_lblk_t ee_block, ex_end, lblk; ext4_fsblk_t pblk; /* find extent for or closest extent to this block */ path = ext4_find_extent(inode, end, NULL, EXT4_EX_NOCACHE | EXT4_EX_NOFAIL); if (IS_ERR(path)) { ext4_journal_stop(handle); return PTR_ERR(path); } depth = ext_depth(inode); /* Leaf not may not exist only if inode has no blocks at all */ ex = path[depth].p_ext; if (!ex) { if (depth) { EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth); err = -EFSCORRUPTED; } goto out; } ee_block = le32_to_cpu(ex->ee_block); ex_end = ee_block + ext4_ext_get_actual_len(ex) - 1; /* * See if the last block is inside the extent, if so split * the extent at 'end' block so we can easily remove the * tail of the first part of the split extent in * ext4_ext_rm_leaf(). */ if (end >= ee_block && end < ex_end) { /* * If we're going to split the extent, note that * the cluster containing the block after 'end' is * in use to avoid freeing it when removing blocks. */ if (sbi->s_cluster_ratio > 1) { pblk = ext4_ext_pblock(ex) + end - ee_block + 1; partial.pclu = EXT4_B2C(sbi, pblk); partial.state = nofree; } /* * Split the extent in two so that 'end' is the last * block in the first new extent. Also we should not * fail removing space due to ENOSPC so try to use * reserved block if that happens. */ err = ext4_force_split_extent_at(handle, inode, &path, end + 1, 1); if (err < 0) goto out; } else if (sbi->s_cluster_ratio > 1 && end >= ex_end && partial.state == initial) { /* * If we're punching, there's an extent to the right. * If the partial cluster hasn't been set, set it to * that extent's first cluster and its state to nofree * so it won't be freed should it contain blocks to be * removed. If it's already set (tofree/nofree), we're * retrying and keep the original partial cluster info * so a cluster marked tofree as a result of earlier * extent removal is not lost. */ lblk = ex_end + 1; err = ext4_ext_search_right(inode, path, &lblk, &pblk, NULL); if (err < 0) goto out; if (pblk) { partial.pclu = EXT4_B2C(sbi, pblk); partial.state = nofree; } } } /* * We start scanning from right side, freeing all the blocks * after i_size and walking into the tree depth-wise. */ depth = ext_depth(inode); if (path) { int k = i = depth; while (--k > 0) path[k].p_block = le16_to_cpu(path[k].p_hdr->eh_entries)+1; } else { path = kcalloc(depth + 1, sizeof(struct ext4_ext_path), GFP_NOFS | __GFP_NOFAIL); if (path == NULL) { ext4_journal_stop(handle); return -ENOMEM; } path[0].p_maxdepth = path[0].p_depth = depth; path[0].p_hdr = ext_inode_hdr(inode); i = 0; if (ext4_ext_check(inode, path[0].p_hdr, depth, 0)) { err = -EFSCORRUPTED; goto out; } } err = 0; while (i >= 0 && err == 0) { if (i == depth) { /* this is leaf block */ err = ext4_ext_rm_leaf(handle, inode, path, &partial, start, end); /* root level has p_bh == NULL, brelse() eats this */ brelse(path[i].p_bh); path[i].p_bh = NULL; i--; continue; } /* this is index block */ if (!path[i].p_hdr) { ext_debug(inode, "initialize header\n"); path[i].p_hdr = ext_block_hdr(path[i].p_bh); } if (!path[i].p_idx) { /* this level hasn't been touched yet */ path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr); path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1; ext_debug(inode, "init index ptr: hdr 0x%p, num %d\n", path[i].p_hdr, le16_to_cpu(path[i].p_hdr->eh_entries)); } else { /* we were already here, see at next index */ path[i].p_idx--; } ext_debug(inode, "level %d - index, first 0x%p, cur 0x%p\n", i, EXT_FIRST_INDEX(path[i].p_hdr), path[i].p_idx); if (ext4_ext_more_to_rm(path + i)) { struct buffer_head *bh; /* go to the next level */ ext_debug(inode, "move to level %d (block %llu)\n", i + 1, ext4_idx_pblock(path[i].p_idx)); memset(path + i + 1, 0, sizeof(*path)); bh = read_extent_tree_block(inode, path[i].p_idx, depth - i - 1, EXT4_EX_NOCACHE); if (IS_ERR(bh)) { /* should we reset i_size? */ err = PTR_ERR(bh); break; } /* Yield here to deal with large extent trees. * Should be a no-op if we did IO above. */ cond_resched(); if (WARN_ON(i + 1 > depth)) { err = -EFSCORRUPTED; break; } path[i + 1].p_bh = bh; /* save actual number of indexes since this * number is changed at the next iteration */ path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries); i++; } else { /* we finished processing this index, go up */ if (path[i].p_hdr->eh_entries == 0 && i > 0) { /* index is empty, remove it; * handle must be already prepared by the * truncatei_leaf() */ err = ext4_ext_rm_idx(handle, inode, path, i); } /* root level has p_bh == NULL, brelse() eats this */ brelse(path[i].p_bh); path[i].p_bh = NULL; i--; ext_debug(inode, "return to level %d\n", i); } } trace_ext4_ext_remove_space_done(inode, start, end, depth, &partial, path->p_hdr->eh_entries); /* * if there's a partial cluster and we have removed the first extent * in the file, then we also free the partial cluster, if any */ if (partial.state == tofree && err == 0) { int flags = get_default_free_blocks_flags(inode); if (ext4_is_pending(inode, partial.lblk)) flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER; ext4_free_blocks(handle, inode, NULL, EXT4_C2B(sbi, partial.pclu), sbi->s_cluster_ratio, flags); if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER) ext4_rereserve_cluster(inode, partial.lblk); partial.state = initial; } /* TODO: flexible tree reduction should be here */ if (path->p_hdr->eh_entries == 0) { /* * truncate to zero freed all the tree, * so we need to correct eh_depth */ err = ext4_ext_get_access(handle, inode, path); if (err == 0) { ext_inode_hdr(inode)->eh_depth = 0; ext_inode_hdr(inode)->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0)); err = ext4_ext_dirty(handle, inode, path); } } out: ext4_free_ext_path(path); path = NULL; if (err == -EAGAIN) goto again; ext4_journal_stop(handle); return err; } /* * called at mount time */ void ext4_ext_init(struct super_block *sb) { /* * possible initialization would be here */ if (ext4_has_feature_extents(sb)) { #if defined(AGGRESSIVE_TEST) || defined(CHECK_BINSEARCH) || defined(EXTENTS_STATS) printk(KERN_INFO "EXT4-fs: file extents enabled" #ifdef AGGRESSIVE_TEST ", aggressive tests" #endif #ifdef CHECK_BINSEARCH ", check binsearch" #endif #ifdef EXTENTS_STATS ", stats" #endif "\n"); #endif #ifdef EXTENTS_STATS spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock); EXT4_SB(sb)->s_ext_min = 1 << 30; EXT4_SB(sb)->s_ext_max = 0; #endif } } /* * called at umount time */ void ext4_ext_release(struct super_block *sb) { if (!ext4_has_feature_extents(sb)) return; #ifdef EXTENTS_STATS if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) { struct ext4_sb_info *sbi = EXT4_SB(sb); printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n", sbi->s_ext_blocks, sbi->s_ext_extents, sbi->s_ext_blocks / sbi->s_ext_extents); printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n", sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max); } #endif } static void ext4_zeroout_es(struct inode *inode, struct ext4_extent *ex) { ext4_lblk_t ee_block; ext4_fsblk_t ee_pblock; unsigned int ee_len; ee_block = le32_to_cpu(ex->ee_block); ee_len = ext4_ext_get_actual_len(ex); ee_pblock = ext4_ext_pblock(ex); if (ee_len == 0) return; ext4_es_insert_extent(inode, ee_block, ee_len, ee_pblock, EXTENT_STATUS_WRITTEN); } /* FIXME!! we need to try to merge to left or right after zero-out */ static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex) { ext4_fsblk_t ee_pblock; unsigned int ee_len; ee_len = ext4_ext_get_actual_len(ex); ee_pblock = ext4_ext_pblock(ex); return ext4_issue_zeroout(inode, le32_to_cpu(ex->ee_block), ee_pblock, ee_len); } /* * ext4_split_extent_at() splits an extent at given block. * * @handle: the journal handle * @inode: the file inode * @path: the path to the extent * @split: the logical block where the extent is splitted. * @split_flags: indicates if the extent could be zeroout if split fails, and * the states(init or unwritten) of new extents. * @flags: flags used to insert new extent to extent tree. * * * Splits extent [a, b] into two extents [a, @split) and [@split, b], states * of which are determined by split_flag. * * There are two cases: * a> the extent are splitted into two extent. * b> split is not needed, and just mark the extent. * * return 0 on success. */ static int ext4_split_extent_at(handle_t *handle, struct inode *inode, struct ext4_ext_path **ppath, ext4_lblk_t split, int split_flag, int flags) { struct ext4_ext_path *path = *ppath; ext4_fsblk_t newblock; ext4_lblk_t ee_block; struct ext4_extent *ex, newex, orig_ex, zero_ex; struct ext4_extent *ex2 = NULL; unsigned int ee_len, depth; int err = 0; BUG_ON((split_flag & (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2)) == (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2)); ext_debug(inode, "logical block %llu\n", (unsigned long long)split); ext4_ext_show_leaf(inode, path); depth = ext_depth(inode); ex = path[depth].p_ext; ee_block = le32_to_cpu(ex->ee_block); ee_len = ext4_ext_get_actual_len(ex); newblock = split - ee_block + ext4_ext_pblock(ex); BUG_ON(split < ee_block || split >= (ee_block + ee_len)); BUG_ON(!ext4_ext_is_unwritten(ex) && split_flag & (EXT4_EXT_MAY_ZEROOUT | EXT4_EXT_MARK_UNWRIT1 | EXT4_EXT_MARK_UNWRIT2)); err = ext4_ext_get_access(handle, inode, path + depth); if (err) goto out; if (split == ee_block) { /* * case b: block @split is the block that the extent begins with * then we just change the state of the extent, and splitting * is not needed. */ if (split_flag & EXT4_EXT_MARK_UNWRIT2) ext4_ext_mark_unwritten(ex); else ext4_ext_mark_initialized(ex); if (!(flags & EXT4_GET_BLOCKS_PRE_IO)) ext4_ext_try_to_merge(handle, inode, path, ex); err = ext4_ext_dirty(handle, inode, path + path->p_depth); goto out; } /* case a */ memcpy(&orig_ex, ex, sizeof(orig_ex)); ex->ee_len = cpu_to_le16(split - ee_block); if (split_flag & EXT4_EXT_MARK_UNWRIT1) ext4_ext_mark_unwritten(ex); /* * path may lead to new leaf, not to original leaf any more * after ext4_ext_insert_extent() returns, */ err = ext4_ext_dirty(handle, inode, path + depth); if (err) goto fix_extent_len; ex2 = &newex; ex2->ee_block = cpu_to_le32(split); ex2->ee_len = cpu_to_le16(ee_len - (split - ee_block)); ext4_ext_store_pblock(ex2, newblock); if (split_flag & EXT4_EXT_MARK_UNWRIT2) ext4_ext_mark_unwritten(ex2); err = ext4_ext_insert_extent(handle, inode, ppath, &newex, flags); if (err != -ENOSPC && err != -EDQUOT && err != -ENOMEM) goto out; if (EXT4_EXT_MAY_ZEROOUT & split_flag) { if (split_flag & (EXT4_EXT_DATA_VALID1|EXT4_EXT_DATA_VALID2)) { if (split_flag & EXT4_EXT_DATA_VALID1) { err = ext4_ext_zeroout(inode, ex2); zero_ex.ee_block = ex2->ee_block; zero_ex.ee_len = cpu_to_le16( ext4_ext_get_actual_len(ex2)); ext4_ext_store_pblock(&zero_ex, ext4_ext_pblock(ex2)); } else { err = ext4_ext_zeroout(inode, ex); zero_ex.ee_block = ex->ee_block; zero_ex.ee_len = cpu_to_le16( ext4_ext_get_actual_len(ex)); ext4_ext_store_pblock(&zero_ex, ext4_ext_pblock(ex)); } } else { err = ext4_ext_zeroout(inode, &orig_ex); zero_ex.ee_block = orig_ex.ee_block; zero_ex.ee_len = cpu_to_le16( ext4_ext_get_actual_len(&orig_ex)); ext4_ext_store_pblock(&zero_ex, ext4_ext_pblock(&orig_ex)); } if (!err) { /* update the extent length and mark as initialized */ ex->ee_len = cpu_to_le16(ee_len); ext4_ext_try_to_merge(handle, inode, path, ex); err = ext4_ext_dirty(handle, inode, path + path->p_depth); if (!err) /* update extent status tree */ ext4_zeroout_es(inode, &zero_ex); /* If we failed at this point, we don't know in which * state the extent tree exactly is so don't try to fix * length of the original extent as it may do even more * damage. */ goto out; } } fix_extent_len: ex->ee_len = orig_ex.ee_len; /* * Ignore ext4_ext_dirty return value since we are already in error path * and err is a non-zero error code. */ ext4_ext_dirty(handle, inode, path + path->p_depth); return err; out: ext4_ext_show_leaf(inode, path); return err; } /* * ext4_split_extents() splits an extent and mark extent which is covered * by @map as split_flags indicates * * It may result in splitting the extent into multiple extents (up to three) * There are three possibilities: * a> There is no split required * b> Splits in two extents: Split is happening at either end of the extent * c> Splits in three extents: Somone is splitting in middle of the extent * */ static int ext4_split_extent(handle_t *handle, struct inode *inode, struct ext4_ext_path **ppath, struct ext4_map_blocks *map, int split_flag, int flags) { struct ext4_ext_path *path = *ppath; ext4_lblk_t ee_block; struct ext4_extent *ex; unsigned int ee_len, depth; int err = 0; int unwritten; int split_flag1, flags1; int allocated = map->m_len; depth = ext_depth(inode); ex = path[depth].p_ext; ee_block = le32_to_cpu(ex->ee_block); ee_len = ext4_ext_get_actual_len(ex); unwritten = ext4_ext_is_unwritten(ex); if (map->m_lblk + map->m_len < ee_block + ee_len) { split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT; flags1 = flags | EXT4_GET_BLOCKS_PRE_IO; if (unwritten) split_flag1 |= EXT4_EXT_MARK_UNWRIT1 | EXT4_EXT_MARK_UNWRIT2; if (split_flag & EXT4_EXT_DATA_VALID2) split_flag1 |= EXT4_EXT_DATA_VALID1; err = ext4_split_extent_at(handle, inode, ppath, map->m_lblk + map->m_len, split_flag1, flags1); if (err) goto out; } else { allocated = ee_len - (map->m_lblk - ee_block); } /* * Update path is required because previous ext4_split_extent_at() may * result in split of original leaf or extent zeroout. */ path = ext4_find_extent(inode, map->m_lblk, ppath, flags); if (IS_ERR(path)) return PTR_ERR(path); depth = ext_depth(inode); ex = path[depth].p_ext; if (!ex) { EXT4_ERROR_INODE(inode, "unexpected hole at %lu", (unsigned long) map->m_lblk); return -EFSCORRUPTED; } unwritten = ext4_ext_is_unwritten(ex); if (map->m_lblk >= ee_block) { split_flag1 = split_flag & EXT4_EXT_DATA_VALID2; if (unwritten) { split_flag1 |= EXT4_EXT_MARK_UNWRIT1; split_flag1 |= split_flag & (EXT4_EXT_MAY_ZEROOUT | EXT4_EXT_MARK_UNWRIT2); } err = ext4_split_extent_at(handle, inode, ppath, map->m_lblk, split_flag1, flags); if (err) goto out; } ext4_ext_show_leaf(inode, path); out: return err ? err : allocated; } /* * This function is called by ext4_ext_map_blocks() if someone tries to write * to an unwritten extent. It may result in splitting the unwritten * extent into multiple extents (up to three - one initialized and two * unwritten). * There are three possibilities: * a> There is no split required: Entire extent should be initialized * b> Splits in two extents: Write is happening at either end of the extent * c> Splits in three extents: Somone is writing in middle of the extent * * Pre-conditions: * - The extent pointed to by 'path' is unwritten. * - The extent pointed to by 'path' contains a superset * of the logical span [map->m_lblk, map->m_lblk + map->m_len). * * Post-conditions on success: * - the returned value is the number of blocks beyond map->l_lblk * that are allocated and initialized. * It is guaranteed to be >= map->m_len. */ static int ext4_ext_convert_to_initialized(handle_t *handle, struct inode *inode, struct ext4_map_blocks *map, struct ext4_ext_path **ppath, int flags) { struct ext4_ext_path *path = *ppath; struct ext4_sb_info *sbi; struct ext4_extent_header *eh; struct ext4_map_blocks split_map; struct ext4_extent zero_ex1, zero_ex2; struct ext4_extent *ex, *abut_ex; ext4_lblk_t ee_block, eof_block; unsigned int ee_len, depth, map_len = map->m_len; int allocated = 0, max_zeroout = 0; int err = 0; int split_flag = EXT4_EXT_DATA_VALID2; ext_debug(inode, "logical block %llu, max_blocks %u\n", (unsigned long long)map->m_lblk, map_len); sbi = EXT4_SB(inode->i_sb); eof_block = (EXT4_I(inode)->i_disksize + inode->i_sb->s_blocksize - 1) >> inode->i_sb->s_blocksize_bits; if (eof_block < map->m_lblk + map_len) eof_block = map->m_lblk + map_len; depth = ext_depth(inode); eh = path[depth].p_hdr; ex = path[depth].p_ext; ee_block = le32_to_cpu(ex->ee_block); ee_len = ext4_ext_get_actual_len(ex); zero_ex1.ee_len = 0; zero_ex2.ee_len = 0; trace_ext4_ext_convert_to_initialized_enter(inode, map, ex); /* Pre-conditions */ BUG_ON(!ext4_ext_is_unwritten(ex)); BUG_ON(!in_range(map->m_lblk, ee_block, ee_len)); /* * Attempt to transfer newly initialized blocks from the currently * unwritten extent to its neighbor. This is much cheaper * than an insertion followed by a merge as those involve costly * memmove() calls. Transferring to the left is the common case in * steady state for workloads doing fallocate(FALLOC_FL_KEEP_SIZE) * followed by append writes. * * Limitations of the current logic: * - L1: we do not deal with writes covering the whole extent. * This would require removing the extent if the transfer * is possible. * - L2: we only attempt to merge with an extent stored in the * same extent tree node. */ if ((map->m_lblk == ee_block) && /* See if we can merge left */ (map_len < ee_len) && /*L1*/ (ex > EXT_FIRST_EXTENT(eh))) { /*L2*/ ext4_lblk_t prev_lblk; ext4_fsblk_t prev_pblk, ee_pblk; unsigned int prev_len; abut_ex = ex - 1; prev_lblk = le32_to_cpu(abut_ex->ee_block); prev_len = ext4_ext_get_actual_len(abut_ex); prev_pblk = ext4_ext_pblock(abut_ex); ee_pblk = ext4_ext_pblock(ex); /* * A transfer of blocks from 'ex' to 'abut_ex' is allowed * upon those conditions: * - C1: abut_ex is initialized, * - C2: abut_ex is logically abutting ex, * - C3: abut_ex is physically abutting ex, * - C4: abut_ex can receive the additional blocks without * overflowing the (initialized) length limit. */ if ((!ext4_ext_is_unwritten(abut_ex)) && /*C1*/ ((prev_lblk + prev_len) == ee_block) && /*C2*/ ((prev_pblk + prev_len) == ee_pblk) && /*C3*/ (prev_len < (EXT_INIT_MAX_LEN - map_len))) { /*C4*/ err = ext4_ext_get_access(handle, inode, path + depth); if (err) goto out; trace_ext4_ext_convert_to_initialized_fastpath(inode, map, ex, abut_ex); /* Shift the start of ex by 'map_len' blocks */ ex->ee_block = cpu_to_le32(ee_block + map_len); ext4_ext_store_pblock(ex, ee_pblk + map_len); ex->ee_len = cpu_to_le16(ee_len - map_len); ext4_ext_mark_unwritten(ex); /* Restore the flag */ /* Extend abut_ex by 'map_len' blocks */ abut_ex->ee_len = cpu_to_le16(prev_len + map_len); /* Result: number of initialized blocks past m_lblk */ allocated = map_len; } } else if (((map->m_lblk + map_len) == (ee_block + ee_len)) && (map_len < ee_len) && /*L1*/ ex < EXT_LAST_EXTENT(eh)) { /*L2*/ /* See if we can merge right */ ext4_lblk_t next_lblk; ext4_fsblk_t next_pblk, ee_pblk; unsigned int next_len; abut_ex = ex + 1; next_lblk = le32_to_cpu(abut_ex->ee_block); next_len = ext4_ext_get_actual_len(abut_ex); next_pblk = ext4_ext_pblock(abut_ex); ee_pblk = ext4_ext_pblock(ex); /* * A transfer of blocks from 'ex' to 'abut_ex' is allowed * upon those conditions: * - C1: abut_ex is initialized, * - C2: abut_ex is logically abutting ex, * - C3: abut_ex is physically abutting ex, * - C4: abut_ex can receive the additional blocks without * overflowing the (initialized) length limit. */ if ((!ext4_ext_is_unwritten(abut_ex)) && /*C1*/ ((map->m_lblk + map_len) == next_lblk) && /*C2*/ ((ee_pblk + ee_len) == next_pblk) && /*C3*/ (next_len < (EXT_INIT_MAX_LEN - map_len))) { /*C4*/ err = ext4_ext_get_access(handle, inode, path + depth); if (err) goto out; trace_ext4_ext_convert_to_initialized_fastpath(inode, map, ex, abut_ex); /* Shift the start of abut_ex by 'map_len' blocks */ abut_ex->ee_block = cpu_to_le32(next_lblk - map_len); ext4_ext_store_pblock(abut_ex, next_pblk - map_len); ex->ee_len = cpu_to_le16(ee_len - map_len); ext4_ext_mark_unwritten(ex); /* Restore the flag */ /* Extend abut_ex by 'map_len' blocks */ abut_ex->ee_len = cpu_to_le16(next_len + map_len); /* Result: number of initialized blocks past m_lblk */ allocated = map_len; } } if (allocated) { /* Mark the block containing both extents as dirty */ err = ext4_ext_dirty(handle, inode, path + depth); /* Update path to point to the right extent */ path[depth].p_ext = abut_ex; goto out; } else allocated = ee_len - (map->m_lblk - ee_block); WARN_ON(map->m_lblk < ee_block); /* * It is safe to convert extent to initialized via explicit * zeroout only if extent is fully inside i_size or new_size. */ split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0; if (EXT4_EXT_MAY_ZEROOUT & split_flag) max_zeroout = sbi->s_extent_max_zeroout_kb >> (inode->i_sb->s_blocksize_bits - 10); /* * five cases: * 1. split the extent into three extents. * 2. split the extent into two extents, zeroout the head of the first * extent. * 3. split the extent into two extents, zeroout the tail of the second * extent. * 4. split the extent into two extents with out zeroout. * 5. no splitting needed, just possibly zeroout the head and / or the * tail of the extent. */ split_map.m_lblk = map->m_lblk; split_map.m_len = map->m_len; if (max_zeroout && (allocated > split_map.m_len)) { if (allocated <= max_zeroout) { /* case 3 or 5 */ zero_ex1.ee_block = cpu_to_le32(split_map.m_lblk + split_map.m_len); zero_ex1.ee_len = cpu_to_le16(allocated - split_map.m_len); ext4_ext_store_pblock(&zero_ex1, ext4_ext_pblock(ex) + split_map.m_lblk + split_map.m_len - ee_block); err = ext4_ext_zeroout(inode, &zero_ex1); if (err) goto fallback; split_map.m_len = allocated; } if (split_map.m_lblk - ee_block + split_map.m_len < max_zeroout) { /* case 2 or 5 */ if (split_map.m_lblk != ee_block) { zero_ex2.ee_block = ex->ee_block; zero_ex2.ee_len = cpu_to_le16(split_map.m_lblk - ee_block); ext4_ext_store_pblock(&zero_ex2, ext4_ext_pblock(ex)); err = ext4_ext_zeroout(inode, &zero_ex2); if (err) goto fallback; } split_map.m_len += split_map.m_lblk - ee_block; split_map.m_lblk = ee_block; allocated = map->m_len; } } fallback: err = ext4_split_extent(handle, inode, ppath, &split_map, split_flag, flags); if (err > 0) err = 0; out: /* If we have gotten a failure, don't zero out status tree */ if (!err) { ext4_zeroout_es(inode, &zero_ex1); ext4_zeroout_es(inode, &zero_ex2); } return err ? err : allocated; } /* * This function is called by ext4_ext_map_blocks() from * ext4_get_blocks_dio_write() when DIO to write * to an unwritten extent. * * Writing to an unwritten extent may result in splitting the unwritten * extent into multiple initialized/unwritten extents (up to three) * There are three possibilities: * a> There is no split required: Entire extent should be unwritten * b> Splits in two extents: Write is happening at either end of the extent * c> Splits in three extents: Somone is writing in middle of the extent * * This works the same way in the case of initialized -> unwritten conversion. * * One of more index blocks maybe needed if the extent tree grow after * the unwritten extent split. To prevent ENOSPC occur at the IO * complete, we need to split the unwritten extent before DIO submit * the IO. The unwritten extent called at this time will be split * into three unwritten extent(at most). After IO complete, the part * being filled will be convert to initialized by the end_io callback function * via ext4_convert_unwritten_extents(). * * Returns the size of unwritten extent to be written on success. */ static int ext4_split_convert_extents(handle_t *handle, struct inode *inode, struct ext4_map_blocks *map, struct ext4_ext_path **ppath, int flags) { struct ext4_ext_path *path = *ppath; ext4_lblk_t eof_block; ext4_lblk_t ee_block; struct ext4_extent *ex; unsigned int ee_len; int split_flag = 0, depth; ext_debug(inode, "logical block %llu, max_blocks %u\n", (unsigned long long)map->m_lblk, map->m_len); eof_block = (EXT4_I(inode)->i_disksize + inode->i_sb->s_blocksize - 1) >> inode->i_sb->s_blocksize_bits; if (eof_block < map->m_lblk + map->m_len) eof_block = map->m_lblk + map->m_len; /* * It is safe to convert extent to initialized via explicit * zeroout only if extent is fully inside i_size or new_size. */ depth = ext_depth(inode); ex = path[depth].p_ext; ee_block = le32_to_cpu(ex->ee_block); ee_len = ext4_ext_get_actual_len(ex); /* Convert to unwritten */ if (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN) { split_flag |= EXT4_EXT_DATA_VALID1; /* Convert to initialized */ } else if (flags & EXT4_GET_BLOCKS_CONVERT) { split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0; split_flag |= (EXT4_EXT_MARK_UNWRIT2 | EXT4_EXT_DATA_VALID2); } flags |= EXT4_GET_BLOCKS_PRE_IO; return ext4_split_extent(handle, inode, ppath, map, split_flag, flags); } static int ext4_convert_unwritten_extents_endio(handle_t *handle, struct inode *inode, struct ext4_map_blocks *map, struct ext4_ext_path **ppath) { struct ext4_ext_path *path = *ppath; struct ext4_extent *ex; ext4_lblk_t ee_block; unsigned int ee_len; int depth; int err = 0; depth = ext_depth(inode); ex = path[depth].p_ext; ee_block = le32_to_cpu(ex->ee_block); ee_len = ext4_ext_get_actual_len(ex); ext_debug(inode, "logical block %llu, max_blocks %u\n", (unsigned long long)ee_block, ee_len); /* If extent is larger than requested it is a clear sign that we still * have some extent state machine issues left. So extent_split is still * required. * TODO: Once all related issues will be fixed this situation should be * illegal. */ if (ee_block != map->m_lblk || ee_len > map->m_len) { #ifdef CONFIG_EXT4_DEBUG ext4_warning(inode->i_sb, "Inode (%ld) finished: extent logical block %llu," " len %u; IO logical block %llu, len %u", inode->i_ino, (unsigned long long)ee_block, ee_len, (unsigned long long)map->m_lblk, map->m_len); #endif err = ext4_split_convert_extents(handle, inode, map, ppath, EXT4_GET_BLOCKS_CONVERT); if (err < 0) return err; path = ext4_find_extent(inode, map->m_lblk, ppath, 0); if (IS_ERR(path)) return PTR_ERR(path); depth = ext_depth(inode); ex = path[depth].p_ext; } err = ext4_ext_get_access(handle, inode, path + depth); if (err) goto out; /* first mark the extent as initialized */ ext4_ext_mark_initialized(ex); /* note: ext4_ext_correct_indexes() isn't needed here because * borders are not changed */ ext4_ext_try_to_merge(handle, inode, path, ex); /* Mark modified extent as dirty */ err = ext4_ext_dirty(handle, inode, path + path->p_depth); out: ext4_ext_show_leaf(inode, path); return err; } static int convert_initialized_extent(handle_t *handle, struct inode *inode, struct ext4_map_blocks *map, struct ext4_ext_path **ppath, unsigned int *allocated) { struct ext4_ext_path *path = *ppath; struct ext4_extent *ex; ext4_lblk_t ee_block; unsigned int ee_len; int depth; int err = 0; /* * Make sure that the extent is no bigger than we support with * unwritten extent */ if (map->m_len > EXT_UNWRITTEN_MAX_LEN) map->m_len = EXT_UNWRITTEN_MAX_LEN / 2; depth = ext_depth(inode); ex = path[depth].p_ext; ee_block = le32_to_cpu(ex->ee_block); ee_len = ext4_ext_get_actual_len(ex); ext_debug(inode, "logical block %llu, max_blocks %u\n", (unsigned long long)ee_block, ee_len); if (ee_block != map->m_lblk || ee_len > map->m_len) { err = ext4_split_convert_extents(handle, inode, map, ppath, EXT4_GET_BLOCKS_CONVERT_UNWRITTEN); if (err < 0) return err; path = ext4_find_extent(inode, map->m_lblk, ppath, 0); if (IS_ERR(path)) return PTR_ERR(path); depth = ext_depth(inode); ex = path[depth].p_ext; if (!ex) { EXT4_ERROR_INODE(inode, "unexpected hole at %lu", (unsigned long) map->m_lblk); return -EFSCORRUPTED; } } err = ext4_ext_get_access(handle, inode, path + depth); if (err) return err; /* first mark the extent as unwritten */ ext4_ext_mark_unwritten(ex); /* note: ext4_ext_correct_indexes() isn't needed here because * borders are not changed */ ext4_ext_try_to_merge(handle, inode, path, ex); /* Mark modified extent as dirty */ err = ext4_ext_dirty(handle, inode, path + path->p_depth); if (err) return err; ext4_ext_show_leaf(inode, path); ext4_update_inode_fsync_trans(handle, inode, 1); map->m_flags |= EXT4_MAP_UNWRITTEN; if (*allocated > map->m_len) *allocated = map->m_len; map->m_len = *allocated; return 0; } static int ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode, struct ext4_map_blocks *map, struct ext4_ext_path **ppath, int flags, unsigned int allocated, ext4_fsblk_t newblock) { struct ext4_ext_path __maybe_unused *path = *ppath; int ret = 0; int err = 0; ext_debug(inode, "logical block %llu, max_blocks %u, flags 0x%x, allocated %u\n", (unsigned long long)map->m_lblk, map->m_len, flags, allocated); ext4_ext_show_leaf(inode, path); /* * When writing into unwritten space, we should not fail to * allocate metadata blocks for the new extent block if needed. */ flags |= EXT4_GET_BLOCKS_METADATA_NOFAIL; trace_ext4_ext_handle_unwritten_extents(inode, map, flags, allocated, newblock); /* get_block() before submitting IO, split the extent */ if (flags & EXT4_GET_BLOCKS_PRE_IO) { ret = ext4_split_convert_extents(handle, inode, map, ppath, flags | EXT4_GET_BLOCKS_CONVERT); if (ret < 0) { err = ret; goto out2; } /* * shouldn't get a 0 return when splitting an extent unless * m_len is 0 (bug) or extent has been corrupted */ if (unlikely(ret == 0)) { EXT4_ERROR_INODE(inode, "unexpected ret == 0, m_len = %u", map->m_len); err = -EFSCORRUPTED; goto out2; } map->m_flags |= EXT4_MAP_UNWRITTEN; goto out; } /* IO end_io complete, convert the filled extent to written */ if (flags & EXT4_GET_BLOCKS_CONVERT) { err = ext4_convert_unwritten_extents_endio(handle, inode, map, ppath); if (err < 0) goto out2; ext4_update_inode_fsync_trans(handle, inode, 1); goto map_out; } /* buffered IO cases */ /* * repeat fallocate creation request * we already have an unwritten extent */ if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT) { map->m_flags |= EXT4_MAP_UNWRITTEN; goto map_out; } /* buffered READ or buffered write_begin() lookup */ if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) { /* * We have blocks reserved already. We * return allocated blocks so that delalloc * won't do block reservation for us. But * the buffer head will be unmapped so that * a read from the block returns 0s. */ map->m_flags |= EXT4_MAP_UNWRITTEN; goto out1; } /* * Default case when (flags & EXT4_GET_BLOCKS_CREATE) == 1. * For buffered writes, at writepage time, etc. Convert a * discovered unwritten extent to written. */ ret = ext4_ext_convert_to_initialized(handle, inode, map, ppath, flags); if (ret < 0) { err = ret; goto out2; } ext4_update_inode_fsync_trans(handle, inode, 1); /* * shouldn't get a 0 return when converting an unwritten extent * unless m_len is 0 (bug) or extent has been corrupted */ if (unlikely(ret == 0)) { EXT4_ERROR_INODE(inode, "unexpected ret == 0, m_len = %u", map->m_len); err = -EFSCORRUPTED; goto out2; } out: allocated = ret; map->m_flags |= EXT4_MAP_NEW; map_out: map->m_flags |= EXT4_MAP_MAPPED; out1: map->m_pblk = newblock; if (allocated > map->m_len) allocated = map->m_len; map->m_len = allocated; ext4_ext_show_leaf(inode, path); out2: return err ? err : allocated; } /* * get_implied_cluster_alloc - check to see if the requested * allocation (in the map structure) overlaps with a cluster already * allocated in an extent. * @sb The filesystem superblock structure * @map The requested lblk->pblk mapping * @ex The extent structure which might contain an implied * cluster allocation * * This function is called by ext4_ext_map_blocks() after we failed to * find blocks that were already in the inode's extent tree. Hence, * we know that the beginning of the requested region cannot overlap * the extent from the inode's extent tree. There are three cases we * want to catch. The first is this case: * * |--- cluster # N--| * |--- extent ---| |---- requested region ---| * |==========| * * The second case that we need to test for is this one: * * |--------- cluster # N ----------------| * |--- requested region --| |------- extent ----| * |=======================| * * The third case is when the requested region lies between two extents * within the same cluster: * |------------- cluster # N-------------| * |----- ex -----| |---- ex_right ----| * |------ requested region ------| * |================| * * In each of the above cases, we need to set the map->m_pblk and * map->m_len so it corresponds to the return the extent labelled as * "|====|" from cluster #N, since it is already in use for data in * cluster EXT4_B2C(sbi, map->m_lblk). We will then return 1 to * signal to ext4_ext_map_blocks() that map->m_pblk should be treated * as a new "allocated" block region. Otherwise, we will return 0 and * ext4_ext_map_blocks() will then allocate one or more new clusters * by calling ext4_mb_new_blocks(). */ static int get_implied_cluster_alloc(struct super_block *sb, struct ext4_map_blocks *map, struct ext4_extent *ex, struct ext4_ext_path *path) { struct ext4_sb_info *sbi = EXT4_SB(sb); ext4_lblk_t c_offset = EXT4_LBLK_COFF(sbi, map->m_lblk); ext4_lblk_t ex_cluster_start, ex_cluster_end; ext4_lblk_t rr_cluster_start; ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block); ext4_fsblk_t ee_start = ext4_ext_pblock(ex); unsigned short ee_len = ext4_ext_get_actual_len(ex); /* The extent passed in that we are trying to match */ ex_cluster_start = EXT4_B2C(sbi, ee_block); ex_cluster_end = EXT4_B2C(sbi, ee_block + ee_len - 1); /* The requested region passed into ext4_map_blocks() */ rr_cluster_start = EXT4_B2C(sbi, map->m_lblk); if ((rr_cluster_start == ex_cluster_end) || (rr_cluster_start == ex_cluster_start)) { if (rr_cluster_start == ex_cluster_end) ee_start += ee_len - 1; map->m_pblk = EXT4_PBLK_CMASK(sbi, ee_start) + c_offset; map->m_len = min(map->m_len, (unsigned) sbi->s_cluster_ratio - c_offset); /* * Check for and handle this case: * * |--------- cluster # N-------------| * |------- extent ----| * |--- requested region ---| * |===========| */ if (map->m_lblk < ee_block) map->m_len = min(map->m_len, ee_block - map->m_lblk); /* * Check for the case where there is already another allocated * block to the right of 'ex' but before the end of the cluster. * * |------------- cluster # N-------------| * |----- ex -----| |---- ex_right ----| * |------ requested region ------| * |================| */ if (map->m_lblk > ee_block) { ext4_lblk_t next = ext4_ext_next_allocated_block(path); map->m_len = min(map->m_len, next - map->m_lblk); } trace_ext4_get_implied_cluster_alloc_exit(sb, map, 1); return 1; } trace_ext4_get_implied_cluster_alloc_exit(sb, map, 0); return 0; } /* * Determine hole length around the given logical block, first try to * locate and expand the hole from the given @path, and then adjust it * if it's partially or completely converted to delayed extents, insert * it into the extent cache tree if it's indeed a hole, finally return * the length of the determined extent. */ static ext4_lblk_t ext4_ext_determine_insert_hole(struct inode *inode, struct ext4_ext_path *path, ext4_lblk_t lblk) { ext4_lblk_t hole_start, len; struct extent_status es; hole_start = lblk; len = ext4_ext_find_hole(inode, path, &hole_start); again: ext4_es_find_extent_range(inode, &ext4_es_is_delayed, hole_start, hole_start + len - 1, &es); if (!es.es_len) goto insert_hole; /* * There's a delalloc extent in the hole, handle it if the delalloc * extent is in front of, behind and straddle the queried range. */ if (lblk >= es.es_lblk + es.es_len) { /* * The delalloc extent is in front of the queried range, * find again from the queried start block. */ len -= lblk - hole_start; hole_start = lblk; goto again; } else if (in_range(lblk, es.es_lblk, es.es_len)) { /* * The delalloc extent containing lblk, it must have been * added after ext4_map_blocks() checked the extent status * tree so we are not holding i_rwsem and delalloc info is * only stabilized by i_data_sem we are going to release * soon. Don't modify the extent status tree and report * extent as a hole, just adjust the length to the delalloc * extent's after lblk. */ len = es.es_lblk + es.es_len - lblk; return len; } else { /* * The delalloc extent is partially or completely behind * the queried range, update hole length until the * beginning of the delalloc extent. */ len = min(es.es_lblk - hole_start, len); } insert_hole: /* Put just found gap into cache to speed up subsequent requests */ ext_debug(inode, " -> %u:%u\n", hole_start, len); ext4_es_insert_extent(inode, hole_start, len, ~0, EXTENT_STATUS_HOLE); /* Update hole_len to reflect hole size after lblk */ if (hole_start != lblk) len -= lblk - hole_start; return len; } /* * Block allocation/map/preallocation routine for extents based files * * * Need to be called with * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block * (ie, flags is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem) * * return > 0, number of blocks already mapped/allocated * if flags doesn't contain EXT4_GET_BLOCKS_CREATE and these are pre-allocated blocks * buffer head is unmapped * otherwise blocks are mapped * * return = 0, if plain look up failed (blocks have not been allocated) * buffer head is unmapped * * return < 0, error case. */ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode, struct ext4_map_blocks *map, int flags) { struct ext4_ext_path *path = NULL; struct ext4_extent newex, *ex, ex2; struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); ext4_fsblk_t newblock = 0, pblk; int err = 0, depth, ret; unsigned int allocated = 0, offset = 0; unsigned int allocated_clusters = 0; struct ext4_allocation_request ar; ext4_lblk_t cluster_offset; ext_debug(inode, "blocks %u/%u requested\n", map->m_lblk, map->m_len); trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags); /* find extent for this block */ path = ext4_find_extent(inode, map->m_lblk, NULL, 0); if (IS_ERR(path)) { err = PTR_ERR(path); path = NULL; goto out; } depth = ext_depth(inode); /* * consistent leaf must not be empty; * this situation is possible, though, _during_ tree modification; * this is why assert can't be put in ext4_find_extent() */ if (unlikely(path[depth].p_ext == NULL && depth != 0)) { EXT4_ERROR_INODE(inode, "bad extent address " "lblock: %lu, depth: %d pblock %lld", (unsigned long) map->m_lblk, depth, path[depth].p_block); err = -EFSCORRUPTED; goto out; } ex = path[depth].p_ext; if (ex) { ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block); ext4_fsblk_t ee_start = ext4_ext_pblock(ex); unsigned short ee_len; /* * unwritten extents are treated as holes, except that * we split out initialized portions during a write. */ ee_len = ext4_ext_get_actual_len(ex); trace_ext4_ext_show_extent(inode, ee_block, ee_start, ee_len); /* if found extent covers block, simply return it */ if (in_range(map->m_lblk, ee_block, ee_len)) { newblock = map->m_lblk - ee_block + ee_start; /* number of remaining blocks in the extent */ allocated = ee_len - (map->m_lblk - ee_block); ext_debug(inode, "%u fit into %u:%d -> %llu\n", map->m_lblk, ee_block, ee_len, newblock); /* * If the extent is initialized check whether the * caller wants to convert it to unwritten. */ if ((!ext4_ext_is_unwritten(ex)) && (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN)) { err = convert_initialized_extent(handle, inode, map, &path, &allocated); goto out; } else if (!ext4_ext_is_unwritten(ex)) { map->m_flags |= EXT4_MAP_MAPPED; map->m_pblk = newblock; if (allocated > map->m_len) allocated = map->m_len; map->m_len = allocated; ext4_ext_show_leaf(inode, path); goto out; } ret = ext4_ext_handle_unwritten_extents( handle, inode, map, &path, flags, allocated, newblock); if (ret < 0) err = ret; else allocated = ret; goto out; } } /* * requested block isn't allocated yet; * we couldn't try to create block if flags doesn't contain EXT4_GET_BLOCKS_CREATE */ if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) { ext4_lblk_t len; len = ext4_ext_determine_insert_hole(inode, path, map->m_lblk); map->m_pblk = 0; map->m_len = min_t(unsigned int, map->m_len, len); goto out; } /* * Okay, we need to do block allocation. */ newex.ee_block = cpu_to_le32(map->m_lblk); cluster_offset = EXT4_LBLK_COFF(sbi, map->m_lblk); /* * If we are doing bigalloc, check to see if the extent returned * by ext4_find_extent() implies a cluster we can use. */ if (cluster_offset && ex && get_implied_cluster_alloc(inode->i_sb, map, ex, path)) { ar.len = allocated = map->m_len; newblock = map->m_pblk; goto got_allocated_blocks; } /* find neighbour allocated blocks */ ar.lleft = map->m_lblk; err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft); if (err) goto out; ar.lright = map->m_lblk; err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright, &ex2); if (err < 0) goto out; /* Check if the extent after searching to the right implies a * cluster we can use. */ if ((sbi->s_cluster_ratio > 1) && err && get_implied_cluster_alloc(inode->i_sb, map, &ex2, path)) { ar.len = allocated = map->m_len; newblock = map->m_pblk; goto got_allocated_blocks; } /* * See if request is beyond maximum number of blocks we can have in * a single extent. For an initialized extent this limit is * EXT_INIT_MAX_LEN and for an unwritten extent this limit is * EXT_UNWRITTEN_MAX_LEN. */ if (map->m_len > EXT_INIT_MAX_LEN && !(flags & EXT4_GET_BLOCKS_UNWRIT_EXT)) map->m_len = EXT_INIT_MAX_LEN; else if (map->m_len > EXT_UNWRITTEN_MAX_LEN && (flags & EXT4_GET_BLOCKS_UNWRIT_EXT)) map->m_len = EXT_UNWRITTEN_MAX_LEN; /* Check if we can really insert (m_lblk)::(m_lblk + m_len) extent */ newex.ee_len = cpu_to_le16(map->m_len); err = ext4_ext_check_overlap(sbi, inode, &newex, path); if (err) allocated = ext4_ext_get_actual_len(&newex); else allocated = map->m_len; /* allocate new block */ ar.inode = inode; ar.goal = ext4_ext_find_goal(inode, path, map->m_lblk); ar.logical = map->m_lblk; /* * We calculate the offset from the beginning of the cluster * for the logical block number, since when we allocate a * physical cluster, the physical block should start at the * same offset from the beginning of the cluster. This is * needed so that future calls to get_implied_cluster_alloc() * work correctly. */ offset = EXT4_LBLK_COFF(sbi, map->m_lblk); ar.len = EXT4_NUM_B2C(sbi, offset+allocated); ar.goal -= offset; ar.logical -= offset; if (S_ISREG(inode->i_mode)) ar.flags = EXT4_MB_HINT_DATA; else /* disable in-core preallocation for non-regular files */ ar.flags = 0; if (flags & EXT4_GET_BLOCKS_NO_NORMALIZE) ar.flags |= EXT4_MB_HINT_NOPREALLOC; if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) ar.flags |= EXT4_MB_DELALLOC_RESERVED; if (flags & EXT4_GET_BLOCKS_METADATA_NOFAIL) ar.flags |= EXT4_MB_USE_RESERVED; newblock = ext4_mb_new_blocks(handle, &ar, &err); if (!newblock) goto out; allocated_clusters = ar.len; ar.len = EXT4_C2B(sbi, ar.len) - offset; ext_debug(inode, "allocate new block: goal %llu, found %llu/%u, requested %u\n", ar.goal, newblock, ar.len, allocated); if (ar.len > allocated) ar.len = allocated; got_allocated_blocks: /* try to insert new extent into found leaf and return */ pblk = newblock + offset; ext4_ext_store_pblock(&newex, pblk); newex.ee_len = cpu_to_le16(ar.len); /* Mark unwritten */ if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT) { ext4_ext_mark_unwritten(&newex); map->m_flags |= EXT4_MAP_UNWRITTEN; } err = ext4_ext_insert_extent(handle, inode, &path, &newex, flags); if (err) { if (allocated_clusters) { int fb_flags = 0; /* * free data blocks we just allocated. * not a good idea to call discard here directly, * but otherwise we'd need to call it every free(). */ ext4_discard_preallocations(inode); if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) fb_flags = EXT4_FREE_BLOCKS_NO_QUOT_UPDATE; ext4_free_blocks(handle, inode, NULL, newblock, EXT4_C2B(sbi, allocated_clusters), fb_flags); } goto out; } /* * Reduce the reserved cluster count to reflect successful deferred * allocation of delayed allocated clusters or direct allocation of * clusters discovered to be delayed allocated. Once allocated, a * cluster is not included in the reserved count. */ if (test_opt(inode->i_sb, DELALLOC) && allocated_clusters) { if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) { /* * When allocating delayed allocated clusters, simply * reduce the reserved cluster count and claim quota */ ext4_da_update_reserve_space(inode, allocated_clusters, 1); } else { ext4_lblk_t lblk, len; unsigned int n; /* * When allocating non-delayed allocated clusters * (from fallocate, filemap, DIO, or clusters * allocated when delalloc has been disabled by * ext4_nonda_switch), reduce the reserved cluster * count by the number of allocated clusters that * have previously been delayed allocated. Quota * has been claimed by ext4_mb_new_blocks() above, * so release the quota reservations made for any * previously delayed allocated clusters. */ lblk = EXT4_LBLK_CMASK(sbi, map->m_lblk); len = allocated_clusters << sbi->s_cluster_bits; n = ext4_es_delayed_clu(inode, lblk, len); if (n > 0) ext4_da_update_reserve_space(inode, (int) n, 0); } } /* * Cache the extent and update transaction to commit on fdatasync only * when it is _not_ an unwritten extent. */ if ((flags & EXT4_GET_BLOCKS_UNWRIT_EXT) == 0) ext4_update_inode_fsync_trans(handle, inode, 1); else ext4_update_inode_fsync_trans(handle, inode, 0); map->m_flags |= (EXT4_MAP_NEW | EXT4_MAP_MAPPED); map->m_pblk = pblk; map->m_len = ar.len; allocated = map->m_len; ext4_ext_show_leaf(inode, path); out: ext4_free_ext_path(path); trace_ext4_ext_map_blocks_exit(inode, flags, map, err ? err : allocated); return err ? err : allocated; } int ext4_ext_truncate(handle_t *handle, struct inode *inode) { struct super_block *sb = inode->i_sb; ext4_lblk_t last_block; int err = 0; /* * TODO: optimization is possible here. * Probably we need not scan at all, * because page truncation is enough. */ /* we have to know where to truncate from in crash case */ EXT4_I(inode)->i_disksize = inode->i_size; err = ext4_mark_inode_dirty(handle, inode); if (err) return err; last_block = (inode->i_size + sb->s_blocksize - 1) >> EXT4_BLOCK_SIZE_BITS(sb); ext4_es_remove_extent(inode, last_block, EXT_MAX_BLOCKS - last_block); retry_remove_space: err = ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1); if (err == -ENOMEM) { memalloc_retry_wait(GFP_ATOMIC); goto retry_remove_space; } return err; } static int ext4_alloc_file_blocks(struct file *file, ext4_lblk_t offset, ext4_lblk_t len, loff_t new_size, int flags) { struct inode *inode = file_inode(file); handle_t *handle; int ret = 0, ret2 = 0, ret3 = 0; int retries = 0; int depth = 0; struct ext4_map_blocks map; unsigned int credits; loff_t epos; BUG_ON(!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)); map.m_lblk = offset; map.m_len = len; /* * Don't normalize the request if it can fit in one extent so * that it doesn't get unnecessarily split into multiple * extents. */ if (len <= EXT_UNWRITTEN_MAX_LEN) flags |= EXT4_GET_BLOCKS_NO_NORMALIZE; /* * credits to insert 1 extent into extent tree */ credits = ext4_chunk_trans_blocks(inode, len); depth = ext_depth(inode); retry: while (len) { /* * Recalculate credits when extent tree depth changes. */ if (depth != ext_depth(inode)) { credits = ext4_chunk_trans_blocks(inode, len); depth = ext_depth(inode); } handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, credits); if (IS_ERR(handle)) { ret = PTR_ERR(handle); break; } ret = ext4_map_blocks(handle, inode, &map, flags); if (ret <= 0) { ext4_debug("inode #%lu: block %u: len %u: " "ext4_ext_map_blocks returned %d", inode->i_ino, map.m_lblk, map.m_len, ret); ext4_mark_inode_dirty(handle, inode); ext4_journal_stop(handle); break; } /* * allow a full retry cycle for any remaining allocations */ retries = 0; map.m_lblk += ret; map.m_len = len = len - ret; epos = (loff_t)map.m_lblk << inode->i_blkbits; inode_set_ctime_current(inode); if (new_size) { if (epos > new_size) epos = new_size; if (ext4_update_inode_size(inode, epos) & 0x1) inode_set_mtime_to_ts(inode, inode_get_ctime(inode)); } ret2 = ext4_mark_inode_dirty(handle, inode); ext4_update_inode_fsync_trans(handle, inode, 1); ret3 = ext4_journal_stop(handle); ret2 = ret3 ? ret3 : ret2; if (unlikely(ret2)) break; } if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) goto retry; return ret > 0 ? ret2 : ret; } static int ext4_collapse_range(struct file *file, loff_t offset, loff_t len); static int ext4_insert_range(struct file *file, loff_t offset, loff_t len); static long ext4_zero_range(struct file *file, loff_t offset, loff_t len, int mode) { struct inode *inode = file_inode(file); struct address_space *mapping = file->f_mapping; handle_t *handle = NULL; unsigned int max_blocks; loff_t new_size = 0; int ret = 0; int flags; int credits; int partial_begin, partial_end; loff_t start, end; ext4_lblk_t lblk; unsigned int blkbits = inode->i_blkbits; trace_ext4_zero_range(inode, offset, len, mode); /* * Round up offset. This is not fallocate, we need to zero out * blocks, so convert interior block aligned part of the range to * unwritten and possibly manually zero out unaligned parts of the * range. Here, start and partial_begin are inclusive, end and * partial_end are exclusive. */ start = round_up(offset, 1 << blkbits); end = round_down((offset + len), 1 << blkbits); if (start < offset || end > offset + len) return -EINVAL; partial_begin = offset & ((1 << blkbits) - 1); partial_end = (offset + len) & ((1 << blkbits) - 1); lblk = start >> blkbits; max_blocks = (end >> blkbits); if (max_blocks < lblk) max_blocks = 0; else max_blocks -= lblk; inode_lock(inode); /* * Indirect files do not support unwritten extents */ if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) { ret = -EOPNOTSUPP; goto out_mutex; } if (!(mode & FALLOC_FL_KEEP_SIZE) && (offset + len > inode->i_size || offset + len > EXT4_I(inode)->i_disksize)) { new_size = offset + len; ret = inode_newsize_ok(inode, new_size); if (ret) goto out_mutex; } flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT; /* Wait all existing dio workers, newcomers will block on i_rwsem */ inode_dio_wait(inode); ret = file_modified(file); if (ret) goto out_mutex; /* Preallocate the range including the unaligned edges */ if (partial_begin || partial_end) { ret = ext4_alloc_file_blocks(file, round_down(offset, 1 << blkbits) >> blkbits, (round_up((offset + len), 1 << blkbits) - round_down(offset, 1 << blkbits)) >> blkbits, new_size, flags); if (ret) goto out_mutex; } /* Zero range excluding the unaligned edges */ if (max_blocks > 0) { flags |= (EXT4_GET_BLOCKS_CONVERT_UNWRITTEN | EXT4_EX_NOCACHE); /* * Prevent page faults from reinstantiating pages we have * released from page cache. */ filemap_invalidate_lock(mapping); ret = ext4_break_layouts(inode); if (ret) { filemap_invalidate_unlock(mapping); goto out_mutex; } ret = ext4_update_disksize_before_punch(inode, offset, len); if (ret) { filemap_invalidate_unlock(mapping); goto out_mutex; } /* * For journalled data we need to write (and checkpoint) pages * before discarding page cache to avoid inconsitent data on * disk in case of crash before zeroing trans is committed. */ if (ext4_should_journal_data(inode)) { ret = filemap_write_and_wait_range(mapping, start, end - 1); if (ret) { filemap_invalidate_unlock(mapping); goto out_mutex; } } /* Now release the pages and zero block aligned part of pages */ truncate_pagecache_range(inode, start, end - 1); inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode)); ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size, flags); filemap_invalidate_unlock(mapping); if (ret) goto out_mutex; } if (!partial_begin && !partial_end) goto out_mutex; /* * In worst case we have to writeout two nonadjacent unwritten * blocks and update the inode */ credits = (2 * ext4_ext_index_trans_blocks(inode, 2)) + 1; if (ext4_should_journal_data(inode)) credits += 2; handle = ext4_journal_start(inode, EXT4_HT_MISC, credits); if (IS_ERR(handle)) { ret = PTR_ERR(handle); ext4_std_error(inode->i_sb, ret); goto out_mutex; } inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode)); if (new_size) ext4_update_inode_size(inode, new_size); ret = ext4_mark_inode_dirty(handle, inode); if (unlikely(ret)) goto out_handle; /* Zero out partial block at the edges of the range */ ret = ext4_zero_partial_blocks(handle, inode, offset, len); if (ret >= 0) ext4_update_inode_fsync_trans(handle, inode, 1); if (file->f_flags & O_SYNC) ext4_handle_sync(handle); out_handle: ext4_journal_stop(handle); out_mutex: inode_unlock(inode); return ret; } /* * preallocate space for a file. This implements ext4's fallocate file * operation, which gets called from sys_fallocate system call. * For block-mapped files, posix_fallocate should fall back to the method * of writing zeroes to the required new blocks (the same behavior which is * expected for file systems which do not support fallocate() system call). */ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len) { struct inode *inode = file_inode(file); loff_t new_size = 0; unsigned int max_blocks; int ret = 0; int flags; ext4_lblk_t lblk; unsigned int blkbits = inode->i_blkbits; /* * Encrypted inodes can't handle collapse range or insert * range since we would need to re-encrypt blocks with a * different IV or XTS tweak (which are based on the logical * block number). */ if (IS_ENCRYPTED(inode) && (mode & (FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_INSERT_RANGE))) return -EOPNOTSUPP; /* Return error if mode is not supported */ if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE | FALLOC_FL_INSERT_RANGE)) return -EOPNOTSUPP; inode_lock(inode); ret = ext4_convert_inline_data(inode); inode_unlock(inode); if (ret) goto exit; if (mode & FALLOC_FL_PUNCH_HOLE) { ret = ext4_punch_hole(file, offset, len); goto exit; } if (mode & FALLOC_FL_COLLAPSE_RANGE) { ret = ext4_collapse_range(file, offset, len); goto exit; } if (mode & FALLOC_FL_INSERT_RANGE) { ret = ext4_insert_range(file, offset, len); goto exit; } if (mode & FALLOC_FL_ZERO_RANGE) { ret = ext4_zero_range(file, offset, len, mode); goto exit; } trace_ext4_fallocate_enter(inode, offset, len, mode); lblk = offset >> blkbits; max_blocks = EXT4_MAX_BLOCKS(len, offset, blkbits); flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT; inode_lock(inode); /* * We only support preallocation for extent-based files only */ if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) { ret = -EOPNOTSUPP; goto out; } if (!(mode & FALLOC_FL_KEEP_SIZE) && (offset + len > inode->i_size || offset + len > EXT4_I(inode)->i_disksize)) { new_size = offset + len; ret = inode_newsize_ok(inode, new_size); if (ret) goto out; } /* Wait all existing dio workers, newcomers will block on i_rwsem */ inode_dio_wait(inode); ret = file_modified(file); if (ret) goto out; ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size, flags); if (ret) goto out; if (file->f_flags & O_SYNC && EXT4_SB(inode->i_sb)->s_journal) { ret = ext4_fc_commit(EXT4_SB(inode->i_sb)->s_journal, EXT4_I(inode)->i_sync_tid); } out: inode_unlock(inode); trace_ext4_fallocate_exit(inode, offset, max_blocks, ret); exit: return ret; } /* * This function convert a range of blocks to written extents * The caller of this function will pass the start offset and the size. * all unwritten extents within this range will be converted to * written extents. * * This function is called from the direct IO end io call back * function, to convert the fallocated extents after IO is completed. * Returns 0 on success. */ int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode, loff_t offset, ssize_t len) { unsigned int max_blocks; int ret = 0, ret2 = 0, ret3 = 0; struct ext4_map_blocks map; unsigned int blkbits = inode->i_blkbits; unsigned int credits = 0; map.m_lblk = offset >> blkbits; max_blocks = EXT4_MAX_BLOCKS(len, offset, blkbits); if (!handle) { /* * credits to insert 1 extent into extent tree */ credits = ext4_chunk_trans_blocks(inode, max_blocks); } while (ret >= 0 && ret < max_blocks) { map.m_lblk += ret; map.m_len = (max_blocks -= ret); if (credits) { handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, credits); if (IS_ERR(handle)) { ret = PTR_ERR(handle); break; } } ret = ext4_map_blocks(handle, inode, &map, EXT4_GET_BLOCKS_IO_CONVERT_EXT); if (ret <= 0) ext4_warning(inode->i_sb, "inode #%lu: block %u: len %u: " "ext4_ext_map_blocks returned %d", inode->i_ino, map.m_lblk, map.m_len, ret); ret2 = ext4_mark_inode_dirty(handle, inode); if (credits) { ret3 = ext4_journal_stop(handle); if (unlikely(ret3)) ret2 = ret3; } if (ret <= 0 || ret2) break; } return ret > 0 ? ret2 : ret; } int ext4_convert_unwritten_io_end_vec(handle_t *handle, ext4_io_end_t *io_end) { int ret = 0, err = 0; struct ext4_io_end_vec *io_end_vec; /* * This is somewhat ugly but the idea is clear: When transaction is * reserved, everything goes into it. Otherwise we rather start several * smaller transactions for conversion of each extent separately. */ if (handle) { handle = ext4_journal_start_reserved(handle, EXT4_HT_EXT_CONVERT); if (IS_ERR(handle)) return PTR_ERR(handle); } list_for_each_entry(io_end_vec, &io_end->list_vec, list) { ret = ext4_convert_unwritten_extents(handle, io_end->inode, io_end_vec->offset, io_end_vec->size); if (ret) break; } if (handle) err = ext4_journal_stop(handle); return ret < 0 ? ret : err; } static int ext4_iomap_xattr_fiemap(struct inode *inode, struct iomap *iomap) { __u64 physical = 0; __u64 length = 0; int blockbits = inode->i_sb->s_blocksize_bits; int error = 0; u16 iomap_type; /* in-inode? */ if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { struct ext4_iloc iloc; int offset; /* offset of xattr in inode */ error = ext4_get_inode_loc(inode, &iloc); if (error) return error; physical = (__u64)iloc.bh->b_blocknr << blockbits; offset = EXT4_GOOD_OLD_INODE_SIZE + EXT4_I(inode)->i_extra_isize; physical += offset; length = EXT4_SB(inode->i_sb)->s_inode_size - offset; brelse(iloc.bh); iomap_type = IOMAP_INLINE; } else if (EXT4_I(inode)->i_file_acl) { /* external block */ physical = (__u64)EXT4_I(inode)->i_file_acl << blockbits; length = inode->i_sb->s_blocksize; iomap_type = IOMAP_MAPPED; } else { /* no in-inode or external block for xattr, so return -ENOENT */ error = -ENOENT; goto out; } iomap->addr = physical; iomap->offset = 0; iomap->length = length; iomap->type = iomap_type; iomap->flags = 0; out: return error; } static int ext4_iomap_xattr_begin(struct inode *inode, loff_t offset, loff_t length, unsigned flags, struct iomap *iomap, struct iomap *srcmap) { int error; error = ext4_iomap_xattr_fiemap(inode, iomap); if (error == 0 && (offset >= iomap->length)) error = -ENOENT; return error; } static const struct iomap_ops ext4_iomap_xattr_ops = { .iomap_begin = ext4_iomap_xattr_begin, }; static int ext4_fiemap_check_ranges(struct inode *inode, u64 start, u64 *len) { u64 maxbytes; if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) maxbytes = inode->i_sb->s_maxbytes; else maxbytes = EXT4_SB(inode->i_sb)->s_bitmap_maxbytes; if (*len == 0) return -EINVAL; if (start > maxbytes) return -EFBIG; /* * Shrink request scope to what the fs can actually handle. */ if (*len > maxbytes || (maxbytes - *len) < start) *len = maxbytes - start; return 0; } int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, u64 start, u64 len) { int error = 0; if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) { error = ext4_ext_precache(inode); if (error) return error; fieinfo->fi_flags &= ~FIEMAP_FLAG_CACHE; } /* * For bitmap files the maximum size limit could be smaller than * s_maxbytes, so check len here manually instead of just relying on the * generic check. */ error = ext4_fiemap_check_ranges(inode, start, &len); if (error) return error; if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) { fieinfo->fi_flags &= ~FIEMAP_FLAG_XATTR; return iomap_fiemap(inode, fieinfo, start, len, &ext4_iomap_xattr_ops); } return iomap_fiemap(inode, fieinfo, start, len, &ext4_iomap_report_ops); } int ext4_get_es_cache(struct inode *inode, struct fiemap_extent_info *fieinfo, __u64 start, __u64 len) { ext4_lblk_t start_blk, len_blks; __u64 last_blk; int error = 0; if (ext4_has_inline_data(inode)) { int has_inline; down_read(&EXT4_I(inode)->xattr_sem); has_inline = ext4_has_inline_data(inode); up_read(&EXT4_I(inode)->xattr_sem); if (has_inline) return 0; } if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) { error = ext4_ext_precache(inode); if (error) return error; fieinfo->fi_flags &= ~FIEMAP_FLAG_CACHE; } error = fiemap_prep(inode, fieinfo, start, &len, 0); if (error) return error; error = ext4_fiemap_check_ranges(inode, start, &len); if (error) return error; start_blk = start >> inode->i_sb->s_blocksize_bits; last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits; if (last_blk >= EXT_MAX_BLOCKS) last_blk = EXT_MAX_BLOCKS-1; len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1; /* * Walk the extent tree gathering extent information * and pushing extents back to the user. */ return ext4_fill_es_cache_info(inode, start_blk, len_blks, fieinfo); } /* * ext4_ext_shift_path_extents: * Shift the extents of a path structure lying between path[depth].p_ext * and EXT_LAST_EXTENT(path[depth].p_hdr), by @shift blocks. @SHIFT tells * if it is right shift or left shift operation. */ static int ext4_ext_shift_path_extents(struct ext4_ext_path *path, ext4_lblk_t shift, struct inode *inode, handle_t *handle, enum SHIFT_DIRECTION SHIFT) { int depth, err = 0; struct ext4_extent *ex_start, *ex_last; bool update = false; int credits, restart_credits; depth = path->p_depth; while (depth >= 0) { if (depth == path->p_depth) { ex_start = path[depth].p_ext; if (!ex_start) return -EFSCORRUPTED; ex_last = EXT_LAST_EXTENT(path[depth].p_hdr); /* leaf + sb + inode */ credits = 3; if (ex_start == EXT_FIRST_EXTENT(path[depth].p_hdr)) { update = true; /* extent tree + sb + inode */ credits = depth + 2; } restart_credits = ext4_writepage_trans_blocks(inode); err = ext4_datasem_ensure_credits(handle, inode, credits, restart_credits, 0); if (err) { if (err > 0) err = -EAGAIN; goto out; } err = ext4_ext_get_access(handle, inode, path + depth); if (err) goto out; while (ex_start <= ex_last) { if (SHIFT == SHIFT_LEFT) { le32_add_cpu(&ex_start->ee_block, -shift); /* Try to merge to the left. */ if ((ex_start > EXT_FIRST_EXTENT(path[depth].p_hdr)) && ext4_ext_try_to_merge_right(inode, path, ex_start - 1)) ex_last--; else ex_start++; } else { le32_add_cpu(&ex_last->ee_block, shift); ext4_ext_try_to_merge_right(inode, path, ex_last); ex_last--; } } err = ext4_ext_dirty(handle, inode, path + depth); if (err) goto out; if (--depth < 0 || !update) break; } /* Update index too */ err = ext4_ext_get_access(handle, inode, path + depth); if (err) goto out; if (SHIFT == SHIFT_LEFT) le32_add_cpu(&path[depth].p_idx->ei_block, -shift); else le32_add_cpu(&path[depth].p_idx->ei_block, shift); err = ext4_ext_dirty(handle, inode, path + depth); if (err) goto out; /* we are done if current index is not a starting index */ if (path[depth].p_idx != EXT_FIRST_INDEX(path[depth].p_hdr)) break; depth--; } out: return err; } /* * ext4_ext_shift_extents: * All the extents which lies in the range from @start to the last allocated * block for the @inode are shifted either towards left or right (depending * upon @SHIFT) by @shift blocks. * On success, 0 is returned, error otherwise. */ static int ext4_ext_shift_extents(struct inode *inode, handle_t *handle, ext4_lblk_t start, ext4_lblk_t shift, enum SHIFT_DIRECTION SHIFT) { struct ext4_ext_path *path; int ret = 0, depth; struct ext4_extent *extent; ext4_lblk_t stop, *iterator, ex_start, ex_end; ext4_lblk_t tmp = EXT_MAX_BLOCKS; /* Let path point to the last extent */ path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL, EXT4_EX_NOCACHE); if (IS_ERR(path)) return PTR_ERR(path); depth = path->p_depth; extent = path[depth].p_ext; if (!extent) goto out; stop = le32_to_cpu(extent->ee_block); /* * For left shifts, make sure the hole on the left is big enough to * accommodate the shift. For right shifts, make sure the last extent * won't be shifted beyond EXT_MAX_BLOCKS. */ if (SHIFT == SHIFT_LEFT) { path = ext4_find_extent(inode, start - 1, &path, EXT4_EX_NOCACHE); if (IS_ERR(path)) return PTR_ERR(path); depth = path->p_depth; extent = path[depth].p_ext; if (extent) { ex_start = le32_to_cpu(extent->ee_block); ex_end = le32_to_cpu(extent->ee_block) + ext4_ext_get_actual_len(extent); } else { ex_start = 0; ex_end = 0; } if ((start == ex_start && shift > ex_start) || (shift > start - ex_end)) { ret = -EINVAL; goto out; } } else { if (shift > EXT_MAX_BLOCKS - (stop + ext4_ext_get_actual_len(extent))) { ret = -EINVAL; goto out; } } /* * In case of left shift, iterator points to start and it is increased * till we reach stop. In case of right shift, iterator points to stop * and it is decreased till we reach start. */ again: ret = 0; if (SHIFT == SHIFT_LEFT) iterator = &start; else iterator = &stop; if (tmp != EXT_MAX_BLOCKS) *iterator = tmp; /* * Its safe to start updating extents. Start and stop are unsigned, so * in case of right shift if extent with 0 block is reached, iterator * becomes NULL to indicate the end of the loop. */ while (iterator && start <= stop) { path = ext4_find_extent(inode, *iterator, &path, EXT4_EX_NOCACHE); if (IS_ERR(path)) return PTR_ERR(path); depth = path->p_depth; extent = path[depth].p_ext; if (!extent) { EXT4_ERROR_INODE(inode, "unexpected hole at %lu", (unsigned long) *iterator); return -EFSCORRUPTED; } if (SHIFT == SHIFT_LEFT && *iterator > le32_to_cpu(extent->ee_block)) { /* Hole, move to the next extent */ if (extent < EXT_LAST_EXTENT(path[depth].p_hdr)) { path[depth].p_ext++; } else { *iterator = ext4_ext_next_allocated_block(path); continue; } } tmp = *iterator; if (SHIFT == SHIFT_LEFT) { extent = EXT_LAST_EXTENT(path[depth].p_hdr); *iterator = le32_to_cpu(extent->ee_block) + ext4_ext_get_actual_len(extent); } else { extent = EXT_FIRST_EXTENT(path[depth].p_hdr); if (le32_to_cpu(extent->ee_block) > start) *iterator = le32_to_cpu(extent->ee_block) - 1; else if (le32_to_cpu(extent->ee_block) == start) iterator = NULL; else { extent = EXT_LAST_EXTENT(path[depth].p_hdr); while (le32_to_cpu(extent->ee_block) >= start) extent--; if (extent == EXT_LAST_EXTENT(path[depth].p_hdr)) break; extent++; iterator = NULL; } path[depth].p_ext = extent; } ret = ext4_ext_shift_path_extents(path, shift, inode, handle, SHIFT); /* iterator can be NULL which means we should break */ if (ret == -EAGAIN) goto again; if (ret) break; } out: ext4_free_ext_path(path); return ret; } /* * ext4_collapse_range: * This implements the fallocate's collapse range functionality for ext4 * Returns: 0 and non-zero on error. */ static int ext4_collapse_range(struct file *file, loff_t offset, loff_t len) { struct inode *inode = file_inode(file); struct super_block *sb = inode->i_sb; struct address_space *mapping = inode->i_mapping; ext4_lblk_t punch_start, punch_stop; handle_t *handle; unsigned int credits; loff_t new_size, ioffset; int ret; /* * We need to test this early because xfstests assumes that a * collapse range of (0, 1) will return EOPNOTSUPP if the file * system does not support collapse range. */ if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) return -EOPNOTSUPP; /* Collapse range works only on fs cluster size aligned regions. */ if (!IS_ALIGNED(offset | len, EXT4_CLUSTER_SIZE(sb))) return -EINVAL; trace_ext4_collapse_range(inode, offset, len); punch_start = offset >> EXT4_BLOCK_SIZE_BITS(sb); punch_stop = (offset + len) >> EXT4_BLOCK_SIZE_BITS(sb); inode_lock(inode); /* * There is no need to overlap collapse range with EOF, in which case * it is effectively a truncate operation */ if (offset + len >= inode->i_size) { ret = -EINVAL; goto out_mutex; } /* Currently just for extent based files */ if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) { ret = -EOPNOTSUPP; goto out_mutex; } /* Wait for existing dio to complete */ inode_dio_wait(inode); ret = file_modified(file); if (ret) goto out_mutex; /* * Prevent page faults from reinstantiating pages we have released from * page cache. */ filemap_invalidate_lock(mapping); ret = ext4_break_layouts(inode); if (ret) goto out_mmap; /* * Need to round down offset to be aligned with page size boundary * for page size > block size. */ ioffset = round_down(offset, PAGE_SIZE); /* * Write tail of the last page before removed range since it will get * removed from the page cache below. */ ret = filemap_write_and_wait_range(mapping, ioffset, offset); if (ret) goto out_mmap; /* * Write data that will be shifted to preserve them when discarding * page cache below. We are also protected from pages becoming dirty * by i_rwsem and invalidate_lock. */ ret = filemap_write_and_wait_range(mapping, offset + len, LLONG_MAX); if (ret) goto out_mmap; truncate_pagecache(inode, ioffset); credits = ext4_writepage_trans_blocks(inode); handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits); if (IS_ERR(handle)) { ret = PTR_ERR(handle); goto out_mmap; } ext4_fc_mark_ineligible(sb, EXT4_FC_REASON_FALLOC_RANGE, handle); down_write(&EXT4_I(inode)->i_data_sem); ext4_discard_preallocations(inode); ext4_es_remove_extent(inode, punch_start, EXT_MAX_BLOCKS - punch_start); ret = ext4_ext_remove_space(inode, punch_start, punch_stop - 1); if (ret) { up_write(&EXT4_I(inode)->i_data_sem); goto out_stop; } ext4_discard_preallocations(inode); ret = ext4_ext_shift_extents(inode, handle, punch_stop, punch_stop - punch_start, SHIFT_LEFT); if (ret) { up_write(&EXT4_I(inode)->i_data_sem); goto out_stop; } new_size = inode->i_size - len; i_size_write(inode, new_size); EXT4_I(inode)->i_disksize = new_size; up_write(&EXT4_I(inode)->i_data_sem); if (IS_SYNC(inode)) ext4_handle_sync(handle); inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode)); ret = ext4_mark_inode_dirty(handle, inode); ext4_update_inode_fsync_trans(handle, inode, 1); out_stop: ext4_journal_stop(handle); out_mmap: filemap_invalidate_unlock(mapping); out_mutex: inode_unlock(inode); return ret; } /* * ext4_insert_range: * This function implements the FALLOC_FL_INSERT_RANGE flag of fallocate. * The data blocks starting from @offset to the EOF are shifted by @len * towards right to create a hole in the @inode. Inode size is increased * by len bytes. * Returns 0 on success, error otherwise. */ static int ext4_insert_range(struct file *file, loff_t offset, loff_t len) { struct inode *inode = file_inode(file); struct super_block *sb = inode->i_sb; struct address_space *mapping = inode->i_mapping; handle_t *handle; struct ext4_ext_path *path; struct ext4_extent *extent; ext4_lblk_t offset_lblk, len_lblk, ee_start_lblk = 0; unsigned int credits, ee_len; int ret = 0, depth, split_flag = 0; loff_t ioffset; /* * We need to test this early because xfstests assumes that an * insert range of (0, 1) will return EOPNOTSUPP if the file * system does not support insert range. */ if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) return -EOPNOTSUPP; /* Insert range works only on fs cluster size aligned regions. */ if (!IS_ALIGNED(offset | len, EXT4_CLUSTER_SIZE(sb))) return -EINVAL; trace_ext4_insert_range(inode, offset, len); offset_lblk = offset >> EXT4_BLOCK_SIZE_BITS(sb); len_lblk = len >> EXT4_BLOCK_SIZE_BITS(sb); inode_lock(inode); /* Currently just for extent based files */ if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) { ret = -EOPNOTSUPP; goto out_mutex; } /* Check whether the maximum file size would be exceeded */ if (len > inode->i_sb->s_maxbytes - inode->i_size) { ret = -EFBIG; goto out_mutex; } /* Offset must be less than i_size */ if (offset >= inode->i_size) { ret = -EINVAL; goto out_mutex; } /* Wait for existing dio to complete */ inode_dio_wait(inode); ret = file_modified(file); if (ret) goto out_mutex; /* * Prevent page faults from reinstantiating pages we have released from * page cache. */ filemap_invalidate_lock(mapping); ret = ext4_break_layouts(inode); if (ret) goto out_mmap; /* * Need to round down to align start offset to page size boundary * for page size > block size. */ ioffset = round_down(offset, PAGE_SIZE); /* Write out all dirty pages */ ret = filemap_write_and_wait_range(inode->i_mapping, ioffset, LLONG_MAX); if (ret) goto out_mmap; truncate_pagecache(inode, ioffset); credits = ext4_writepage_trans_blocks(inode); handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits); if (IS_ERR(handle)) { ret = PTR_ERR(handle); goto out_mmap; } ext4_fc_mark_ineligible(sb, EXT4_FC_REASON_FALLOC_RANGE, handle); /* Expand file to avoid data loss if there is error while shifting */ inode->i_size += len; EXT4_I(inode)->i_disksize += len; inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode)); ret = ext4_mark_inode_dirty(handle, inode); if (ret) goto out_stop; down_write(&EXT4_I(inode)->i_data_sem); ext4_discard_preallocations(inode); path = ext4_find_extent(inode, offset_lblk, NULL, 0); if (IS_ERR(path)) { up_write(&EXT4_I(inode)->i_data_sem); goto out_stop; } depth = ext_depth(inode); extent = path[depth].p_ext; if (extent) { ee_start_lblk = le32_to_cpu(extent->ee_block); ee_len = ext4_ext_get_actual_len(extent); /* * If offset_lblk is not the starting block of extent, split * the extent @offset_lblk */ if ((offset_lblk > ee_start_lblk) && (offset_lblk < (ee_start_lblk + ee_len))) { if (ext4_ext_is_unwritten(extent)) split_flag = EXT4_EXT_MARK_UNWRIT1 | EXT4_EXT_MARK_UNWRIT2; ret = ext4_split_extent_at(handle, inode, &path, offset_lblk, split_flag, EXT4_EX_NOCACHE | EXT4_GET_BLOCKS_PRE_IO | EXT4_GET_BLOCKS_METADATA_NOFAIL); } ext4_free_ext_path(path); if (ret < 0) { up_write(&EXT4_I(inode)->i_data_sem); goto out_stop; } } else { ext4_free_ext_path(path); } ext4_es_remove_extent(inode, offset_lblk, EXT_MAX_BLOCKS - offset_lblk); /* * if offset_lblk lies in a hole which is at start of file, use * ee_start_lblk to shift extents */ ret = ext4_ext_shift_extents(inode, handle, max(ee_start_lblk, offset_lblk), len_lblk, SHIFT_RIGHT); up_write(&EXT4_I(inode)->i_data_sem); if (IS_SYNC(inode)) ext4_handle_sync(handle); if (ret >= 0) ext4_update_inode_fsync_trans(handle, inode, 1); out_stop: ext4_journal_stop(handle); out_mmap: filemap_invalidate_unlock(mapping); out_mutex: inode_unlock(inode); return ret; } /** * ext4_swap_extents() - Swap extents between two inodes * @handle: handle for this transaction * @inode1: First inode * @inode2: Second inode * @lblk1: Start block for first inode * @lblk2: Start block for second inode * @count: Number of blocks to swap * @unwritten: Mark second inode's extents as unwritten after swap * @erp: Pointer to save error value * * This helper routine does exactly what is promise "swap extents". All other * stuff such as page-cache locking consistency, bh mapping consistency or * extent's data copying must be performed by caller. * Locking: * i_rwsem is held for both inodes * i_data_sem is locked for write for both inodes * Assumptions: * All pages from requested range are locked for both inodes */ int ext4_swap_extents(handle_t *handle, struct inode *inode1, struct inode *inode2, ext4_lblk_t lblk1, ext4_lblk_t lblk2, ext4_lblk_t count, int unwritten, int *erp) { struct ext4_ext_path *path1 = NULL; struct ext4_ext_path *path2 = NULL; int replaced_count = 0; BUG_ON(!rwsem_is_locked(&EXT4_I(inode1)->i_data_sem)); BUG_ON(!rwsem_is_locked(&EXT4_I(inode2)->i_data_sem)); BUG_ON(!inode_is_locked(inode1)); BUG_ON(!inode_is_locked(inode2)); ext4_es_remove_extent(inode1, lblk1, count); ext4_es_remove_extent(inode2, lblk2, count); while (count) { struct ext4_extent *ex1, *ex2, tmp_ex; ext4_lblk_t e1_blk, e2_blk; int e1_len, e2_len, len; int split = 0; path1 = ext4_find_extent(inode1, lblk1, NULL, EXT4_EX_NOCACHE); if (IS_ERR(path1)) { *erp = PTR_ERR(path1); path1 = NULL; finish: count = 0; goto repeat; } path2 = ext4_find_extent(inode2, lblk2, NULL, EXT4_EX_NOCACHE); if (IS_ERR(path2)) { *erp = PTR_ERR(path2); path2 = NULL; goto finish; } ex1 = path1[path1->p_depth].p_ext; ex2 = path2[path2->p_depth].p_ext; /* Do we have something to swap ? */ if (unlikely(!ex2 || !ex1)) goto finish; e1_blk = le32_to_cpu(ex1->ee_block); e2_blk = le32_to_cpu(ex2->ee_block); e1_len = ext4_ext_get_actual_len(ex1); e2_len = ext4_ext_get_actual_len(ex2); /* Hole handling */ if (!in_range(lblk1, e1_blk, e1_len) || !in_range(lblk2, e2_blk, e2_len)) { ext4_lblk_t next1, next2; /* if hole after extent, then go to next extent */ next1 = ext4_ext_next_allocated_block(path1); next2 = ext4_ext_next_allocated_block(path2); /* If hole before extent, then shift to that extent */ if (e1_blk > lblk1) next1 = e1_blk; if (e2_blk > lblk2) next2 = e2_blk; /* Do we have something to swap */ if (next1 == EXT_MAX_BLOCKS || next2 == EXT_MAX_BLOCKS) goto finish; /* Move to the rightest boundary */ len = next1 - lblk1; if (len < next2 - lblk2) len = next2 - lblk2; if (len > count) len = count; lblk1 += len; lblk2 += len; count -= len; goto repeat; } /* Prepare left boundary */ if (e1_blk < lblk1) { split = 1; *erp = ext4_force_split_extent_at(handle, inode1, &path1, lblk1, 0); if (unlikely(*erp)) goto finish; } if (e2_blk < lblk2) { split = 1; *erp = ext4_force_split_extent_at(handle, inode2, &path2, lblk2, 0); if (unlikely(*erp)) goto finish; } /* ext4_split_extent_at() may result in leaf extent split, * path must to be revalidated. */ if (split) goto repeat; /* Prepare right boundary */ len = count; if (len > e1_blk + e1_len - lblk1) len = e1_blk + e1_len - lblk1; if (len > e2_blk + e2_len - lblk2) len = e2_blk + e2_len - lblk2; if (len != e1_len) { split = 1; *erp = ext4_force_split_extent_at(handle, inode1, &path1, lblk1 + len, 0); if (unlikely(*erp)) goto finish; } if (len != e2_len) { split = 1; *erp = ext4_force_split_extent_at(handle, inode2, &path2, lblk2 + len, 0); if (*erp) goto finish; } /* ext4_split_extent_at() may result in leaf extent split, * path must to be revalidated. */ if (split) goto repeat; BUG_ON(e2_len != e1_len); *erp = ext4_ext_get_access(handle, inode1, path1 + path1->p_depth); if (unlikely(*erp)) goto finish; *erp = ext4_ext_get_access(handle, inode2, path2 + path2->p_depth); if (unlikely(*erp)) goto finish; /* Both extents are fully inside boundaries. Swap it now */ tmp_ex = *ex1; ext4_ext_store_pblock(ex1, ext4_ext_pblock(ex2)); ext4_ext_store_pblock(ex2, ext4_ext_pblock(&tmp_ex)); ex1->ee_len = cpu_to_le16(e2_len); ex2->ee_len = cpu_to_le16(e1_len); if (unwritten) ext4_ext_mark_unwritten(ex2); if (ext4_ext_is_unwritten(&tmp_ex)) ext4_ext_mark_unwritten(ex1); ext4_ext_try_to_merge(handle, inode2, path2, ex2); ext4_ext_try_to_merge(handle, inode1, path1, ex1); *erp = ext4_ext_dirty(handle, inode2, path2 + path2->p_depth); if (unlikely(*erp)) goto finish; *erp = ext4_ext_dirty(handle, inode1, path1 + path1->p_depth); /* * Looks scarry ah..? second inode already points to new blocks, * and it was successfully dirtied. But luckily error may happen * only due to journal error, so full transaction will be * aborted anyway. */ if (unlikely(*erp)) goto finish; lblk1 += len; lblk2 += len; replaced_count += len; count -= len; repeat: ext4_free_ext_path(path1); ext4_free_ext_path(path2); path1 = path2 = NULL; } return replaced_count; } /* * ext4_clu_mapped - determine whether any block in a logical cluster has * been mapped to a physical cluster * * @inode - file containing the logical cluster * @lclu - logical cluster of interest * * Returns 1 if any block in the logical cluster is mapped, signifying * that a physical cluster has been allocated for it. Otherwise, * returns 0. Can also return negative error codes. Derived from * ext4_ext_map_blocks(). */ int ext4_clu_mapped(struct inode *inode, ext4_lblk_t lclu) { struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); struct ext4_ext_path *path; int depth, mapped = 0, err = 0; struct ext4_extent *extent; ext4_lblk_t first_lblk, first_lclu, last_lclu; /* * if data can be stored inline, the logical cluster isn't * mapped - no physical clusters have been allocated, and the * file has no extents */ if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA) || ext4_has_inline_data(inode)) return 0; /* search for the extent closest to the first block in the cluster */ path = ext4_find_extent(inode, EXT4_C2B(sbi, lclu), NULL, 0); if (IS_ERR(path)) { err = PTR_ERR(path); path = NULL; goto out; } depth = ext_depth(inode); /* * A consistent leaf must not be empty. This situation is possible, * though, _during_ tree modification, and it's why an assert can't * be put in ext4_find_extent(). */ if (unlikely(path[depth].p_ext == NULL && depth != 0)) { EXT4_ERROR_INODE(inode, "bad extent address - lblock: %lu, depth: %d, pblock: %lld", (unsigned long) EXT4_C2B(sbi, lclu), depth, path[depth].p_block); err = -EFSCORRUPTED; goto out; } extent = path[depth].p_ext; /* can't be mapped if the extent tree is empty */ if (extent == NULL) goto out; first_lblk = le32_to_cpu(extent->ee_block); first_lclu = EXT4_B2C(sbi, first_lblk); /* * Three possible outcomes at this point - found extent spanning * the target cluster, to the left of the target cluster, or to the * right of the target cluster. The first two cases are handled here. * The last case indicates the target cluster is not mapped. */ if (lclu >= first_lclu) { last_lclu = EXT4_B2C(sbi, first_lblk + ext4_ext_get_actual_len(extent) - 1); if (lclu <= last_lclu) { mapped = 1; } else { first_lblk = ext4_ext_next_allocated_block(path); first_lclu = EXT4_B2C(sbi, first_lblk); if (lclu == first_lclu) mapped = 1; } } out: ext4_free_ext_path(path); return err ? err : mapped; } /* * Updates physical block address and unwritten status of extent * starting at lblk start and of len. If such an extent doesn't exist, * this function splits the extent tree appropriately to create an * extent like this. This function is called in the fast commit * replay path. Returns 0 on success and error on failure. */ int ext4_ext_replay_update_ex(struct inode *inode, ext4_lblk_t start, int len, int unwritten, ext4_fsblk_t pblk) { struct ext4_ext_path *path = NULL, *ppath; struct ext4_extent *ex; int ret; path = ext4_find_extent(inode, start, NULL, 0); if (IS_ERR(path)) return PTR_ERR(path); ex = path[path->p_depth].p_ext; if (!ex) { ret = -EFSCORRUPTED; goto out; } if (le32_to_cpu(ex->ee_block) != start || ext4_ext_get_actual_len(ex) != len) { /* We need to split this extent to match our extent first */ ppath = path; down_write(&EXT4_I(inode)->i_data_sem); ret = ext4_force_split_extent_at(NULL, inode, &ppath, start, 1); up_write(&EXT4_I(inode)->i_data_sem); if (ret) goto out; kfree(path); path = ext4_find_extent(inode, start, NULL, 0); if (IS_ERR(path)) return -1; ppath = path; ex = path[path->p_depth].p_ext; WARN_ON(le32_to_cpu(ex->ee_block) != start); if (ext4_ext_get_actual_len(ex) != len) { down_write(&EXT4_I(inode)->i_data_sem); ret = ext4_force_split_extent_at(NULL, inode, &ppath, start + len, 1); up_write(&EXT4_I(inode)->i_data_sem); if (ret) goto out; kfree(path); path = ext4_find_extent(inode, start, NULL, 0); if (IS_ERR(path)) return -EINVAL; ex = path[path->p_depth].p_ext; } } if (unwritten) ext4_ext_mark_unwritten(ex); else ext4_ext_mark_initialized(ex); ext4_ext_store_pblock(ex, pblk); down_write(&EXT4_I(inode)->i_data_sem); ret = ext4_ext_dirty(NULL, inode, &path[path->p_depth]); up_write(&EXT4_I(inode)->i_data_sem); out: ext4_free_ext_path(path); ext4_mark_inode_dirty(NULL, inode); return ret; } /* Try to shrink the extent tree */ void ext4_ext_replay_shrink_inode(struct inode *inode, ext4_lblk_t end) { struct ext4_ext_path *path = NULL; struct ext4_extent *ex; ext4_lblk_t old_cur, cur = 0; while (cur < end) { path = ext4_find_extent(inode, cur, NULL, 0); if (IS_ERR(path)) return; ex = path[path->p_depth].p_ext; if (!ex) { ext4_free_ext_path(path); ext4_mark_inode_dirty(NULL, inode); return; } old_cur = cur; cur = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex); if (cur <= old_cur) cur = old_cur + 1; ext4_ext_try_to_merge(NULL, inode, path, ex); down_write(&EXT4_I(inode)->i_data_sem); ext4_ext_dirty(NULL, inode, &path[path->p_depth]); up_write(&EXT4_I(inode)->i_data_sem); ext4_mark_inode_dirty(NULL, inode); ext4_free_ext_path(path); } } /* Check if *cur is a hole and if it is, skip it */ static int skip_hole(struct inode *inode, ext4_lblk_t *cur) { int ret; struct ext4_map_blocks map; map.m_lblk = *cur; map.m_len = ((inode->i_size) >> inode->i_sb->s_blocksize_bits) - *cur; ret = ext4_map_blocks(NULL, inode, &map, 0); if (ret < 0) return ret; if (ret != 0) return 0; *cur = *cur + map.m_len; return 0; } /* Count number of blocks used by this inode and update i_blocks */ int ext4_ext_replay_set_iblocks(struct inode *inode) { struct ext4_ext_path *path = NULL, *path2 = NULL; struct ext4_extent *ex; ext4_lblk_t cur = 0, end; int numblks = 0, i, ret = 0; ext4_fsblk_t cmp1, cmp2; struct ext4_map_blocks map; /* Determin the size of the file first */ path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL, EXT4_EX_NOCACHE); if (IS_ERR(path)) return PTR_ERR(path); ex = path[path->p_depth].p_ext; if (!ex) { ext4_free_ext_path(path); goto out; } end = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex); ext4_free_ext_path(path); /* Count the number of data blocks */ cur = 0; while (cur < end) { map.m_lblk = cur; map.m_len = end - cur; ret = ext4_map_blocks(NULL, inode, &map, 0); if (ret < 0) break; if (ret > 0) numblks += ret; cur = cur + map.m_len; } /* * Count the number of extent tree blocks. We do it by looking up * two successive extents and determining the difference between * their paths. When path is different for 2 successive extents * we compare the blocks in the path at each level and increment * iblocks by total number of differences found. */ cur = 0; ret = skip_hole(inode, &cur); if (ret < 0) goto out; path = ext4_find_extent(inode, cur, NULL, 0); if (IS_ERR(path)) goto out; numblks += path->p_depth; ext4_free_ext_path(path); while (cur < end) { path = ext4_find_extent(inode, cur, NULL, 0); if (IS_ERR(path)) break; ex = path[path->p_depth].p_ext; if (!ex) { ext4_free_ext_path(path); return 0; } cur = max(cur + 1, le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex)); ret = skip_hole(inode, &cur); if (ret < 0) { ext4_free_ext_path(path); break; } path2 = ext4_find_extent(inode, cur, NULL, 0); if (IS_ERR(path2)) { ext4_free_ext_path(path); break; } for (i = 0; i <= max(path->p_depth, path2->p_depth); i++) { cmp1 = cmp2 = 0; if (i <= path->p_depth) cmp1 = path[i].p_bh ? path[i].p_bh->b_blocknr : 0; if (i <= path2->p_depth) cmp2 = path2[i].p_bh ? path2[i].p_bh->b_blocknr : 0; if (cmp1 != cmp2 && cmp2 != 0) numblks++; } ext4_free_ext_path(path); ext4_free_ext_path(path2); } out: inode->i_blocks = numblks << (inode->i_sb->s_blocksize_bits - 9); ext4_mark_inode_dirty(NULL, inode); return 0; } int ext4_ext_clear_bb(struct inode *inode) { struct ext4_ext_path *path = NULL; struct ext4_extent *ex; ext4_lblk_t cur = 0, end; int j, ret = 0; struct ext4_map_blocks map; if (ext4_test_inode_flag(inode, EXT4_INODE_INLINE_DATA)) return 0; /* Determin the size of the file first */ path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL, EXT4_EX_NOCACHE); if (IS_ERR(path)) return PTR_ERR(path); ex = path[path->p_depth].p_ext; if (!ex) { ext4_free_ext_path(path); return 0; } end = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex); ext4_free_ext_path(path); cur = 0; while (cur < end) { map.m_lblk = cur; map.m_len = end - cur; ret = ext4_map_blocks(NULL, inode, &map, 0); if (ret < 0) break; if (ret > 0) { path = ext4_find_extent(inode, map.m_lblk, NULL, 0); if (!IS_ERR_OR_NULL(path)) { for (j = 0; j < path->p_depth; j++) { ext4_mb_mark_bb(inode->i_sb, path[j].p_block, 1, false); ext4_fc_record_regions(inode->i_sb, inode->i_ino, 0, path[j].p_block, 1, 1); } ext4_free_ext_path(path); } ext4_mb_mark_bb(inode->i_sb, map.m_pblk, map.m_len, false); ext4_fc_record_regions(inode->i_sb, inode->i_ino, map.m_lblk, map.m_pblk, map.m_len, 1); } cur = cur + map.m_len; } return 0; }
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