| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Filipe David Borba Manana | 4972 | 31.06% | 89 | 17.05% |
| Chris Mason | 2346 | 14.65% | 85 | 16.28% |
| Josef Bacik | 2134 | 13.33% | 48 | 9.20% |
| Zheng Yan | 1798 | 11.23% | 17 | 3.26% |
| Goldwyn Rodrigues | 948 | 5.92% | 15 | 2.87% |
| Qu Wenruo | 861 | 5.38% | 24 | 4.60% |
| Josef Whiter | 334 | 2.09% | 29 | 5.56% |
| Miao Xie | 317 | 1.98% | 19 | 3.64% |
| Nikolay Borisov | 253 | 1.58% | 38 | 7.28% |
| Christoph Hellwig | 244 | 1.52% | 14 | 2.68% |
| Stefan Roesch | 230 | 1.44% | 5 | 0.96% |
| Omar Sandoval | 215 | 1.34% | 6 | 1.15% |
| Jeff Mahoney | 195 | 1.22% | 5 | 0.96% |
| David Sterba | 138 | 0.86% | 13 | 2.49% |
| Liu Bo | 89 | 0.56% | 8 | 1.53% |
| Christian Brauner | 82 | 0.51% | 1 | 0.19% |
| Chandan Rajendra | 82 | 0.51% | 3 | 0.57% |
| Al Viro | 65 | 0.41% | 8 | 1.53% |
| Jeff Layton | 62 | 0.39% | 4 | 0.77% |
| Xin Zhong | 51 | 0.32% | 1 | 0.19% |
| Darrick J. Wong | 43 | 0.27% | 2 | 0.38% |
| Jie Liu | 37 | 0.23% | 4 | 0.77% |
| Bernd Schubert | 34 | 0.21% | 1 | 0.19% |
| Jens Axboe | 34 | 0.21% | 2 | 0.38% |
| Li Zefan | 30 | 0.19% | 2 | 0.38% |
| Fengguang Wu | 29 | 0.18% | 1 | 0.19% |
| Mingming Cao | 23 | 0.14% | 1 | 0.19% |
| Boris Burkov | 22 | 0.14% | 3 | 0.57% |
| Naohiro Aota | 22 | 0.14% | 4 | 0.77% |
| Shaohua Li | 21 | 0.13% | 1 | 0.19% |
| Yan Zheng | 20 | 0.12% | 2 | 0.38% |
| Johannes Thumshirn | 20 | 0.12% | 2 | 0.38% |
| Kirill A. Shutemov | 18 | 0.11% | 2 | 0.38% |
| Davide Italiano | 16 | 0.10% | 1 | 0.19% |
| Matthew Wilcox | 16 | 0.10% | 3 | 0.57% |
| Xiaoguang Wang | 14 | 0.09% | 1 | 0.19% |
| Bingjing Chang | 14 | 0.09% | 1 | 0.19% |
| Arne Jansen | 12 | 0.07% | 2 | 0.38% |
| Andrew Morton | 11 | 0.07% | 3 | 0.57% |
| David Chinner | 10 | 0.06% | 2 | 0.38% |
| Tsutomu Itoh | 10 | 0.06% | 4 | 0.77% |
| Steven Whitehouse | 9 | 0.06% | 1 | 0.19% |
| Li Dongyang | 9 | 0.06% | 1 | 0.19% |
| Mark Fasheh | 7 | 0.04% | 1 | 0.19% |
| Nikanth Karthikesan | 6 | 0.04% | 1 | 0.19% |
| Jan Kara | 6 | 0.04% | 1 | 0.19% |
| Anand Jain | 6 | 0.04% | 2 | 0.38% |
| Sven Wegener | 5 | 0.03% | 1 | 0.19% |
| Ankit Jain | 5 | 0.03% | 1 | 0.19% |
| Jan Schmidt | 5 | 0.03% | 2 | 0.38% |
| Dongsheng Yang | 5 | 0.03% | 1 | 0.19% |
| Filipe Brandenburger | 5 | 0.03% | 1 | 0.19% |
| Alexander Zhu | 5 | 0.03% | 1 | 0.19% |
| ruanjinjie | 4 | 0.02% | 1 | 0.19% |
| Aneesh Kumar K.V | 4 | 0.02% | 1 | 0.19% |
| Sage Weil | 4 | 0.02% | 1 | 0.19% |
| David Howells | 4 | 0.02% | 2 | 0.38% |
| Amit Arora | 4 | 0.02% | 1 | 0.19% |
| Fabian Frederick | 3 | 0.02% | 1 | 0.19% |
| Zhu Yanhai | 3 | 0.02% | 1 | 0.19% |
| Ritesh Harjani | 3 | 0.02% | 1 | 0.19% |
| Herbert Xu | 3 | 0.02% | 1 | 0.19% |
| Dan Carpenter | 3 | 0.02% | 1 | 0.19% |
| Deepa Dinamani | 3 | 0.02% | 1 | 0.19% |
| Andreas Gruenbacher | 2 | 0.01% | 2 | 0.38% |
| Linus Torvalds (pre-git) | 2 | 0.01% | 1 | 0.19% |
| Yehuda Sadeh Weinraub | 2 | 0.01% | 1 | 0.19% |
| Arnd Bergmann | 2 | 0.01% | 1 | 0.19% |
| Johannes Weiner | 2 | 0.01% | 1 | 0.19% |
| Kent Overstreet | 2 | 0.01% | 1 | 0.19% |
| Zach Brown | 2 | 0.01% | 1 | 0.19% |
| Miklos Szeredi | 2 | 0.01% | 1 | 0.19% |
| Alexey Dobriyan | 2 | 0.01% | 2 | 0.38% |
| Linus Torvalds | 1 | 0.01% | 1 | 0.19% |
| Mel Gorman | 1 | 0.01% | 1 | 0.19% |
| Andi Kleen | 1 | 0.01% | 1 | 0.19% |
| Zhao Lei | 1 | 0.01% | 1 | 0.19% |
| Eric Sandeen | 1 | 0.01% | 1 | 0.19% |
| Luke Dashjr | 1 | 0.01% | 1 | 0.19% |
| Nicholas D Steeves | 1 | 0.01% | 1 | 0.19% |
| Andrea Gelmini | 1 | 0.01% | 1 | 0.19% |
| Roel Kluin | 1 | 0.01% | 1 | 0.19% |
| Total | 16010 | 522 |
// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2007 Oracle. All rights reserved. */ #include <linux/fs.h> #include <linux/pagemap.h> #include <linux/time.h> #include <linux/init.h> #include <linux/string.h> #include <linux/backing-dev.h> #include <linux/falloc.h> #include <linux/writeback.h> #include <linux/compat.h> #include <linux/slab.h> #include <linux/btrfs.h> #include <linux/uio.h> #include <linux/iversion.h> #include <linux/fsverity.h> #include <linux/iomap.h> #include "ctree.h" #include "disk-io.h" #include "transaction.h" #include "btrfs_inode.h" #include "print-tree.h" #include "tree-log.h" #include "locking.h" #include "volumes.h" #include "qgroup.h" #include "compression.h" #include "delalloc-space.h" #include "reflink.h" #include "subpage.h" #include "fs.h" #include "accessors.h" #include "extent-tree.h" #include "file-item.h" #include "ioctl.h" #include "file.h" #include "super.h" /* simple helper to fault in pages and copy. This should go away * and be replaced with calls into generic code. */ static noinline int btrfs_copy_from_user(loff_t pos, size_t write_bytes, struct page **prepared_pages, struct iov_iter *i) { size_t copied = 0; size_t total_copied = 0; int pg = 0; int offset = offset_in_page(pos); while (write_bytes > 0) { size_t count = min_t(size_t, PAGE_SIZE - offset, write_bytes); struct page *page = prepared_pages[pg]; /* * Copy data from userspace to the current page */ copied = copy_page_from_iter_atomic(page, offset, count, i); /* Flush processor's dcache for this page */ flush_dcache_page(page); /* * if we get a partial write, we can end up with * partially up to date pages. These add * a lot of complexity, so make sure they don't * happen by forcing this copy to be retried. * * The rest of the btrfs_file_write code will fall * back to page at a time copies after we return 0. */ if (unlikely(copied < count)) { if (!PageUptodate(page)) { iov_iter_revert(i, copied); copied = 0; } if (!copied) break; } write_bytes -= copied; total_copied += copied; offset += copied; if (offset == PAGE_SIZE) { pg++; offset = 0; } } return total_copied; } /* * unlocks pages after btrfs_file_write is done with them */ static void btrfs_drop_pages(struct btrfs_fs_info *fs_info, struct page **pages, size_t num_pages, u64 pos, u64 copied) { size_t i; u64 block_start = round_down(pos, fs_info->sectorsize); u64 block_len = round_up(pos + copied, fs_info->sectorsize) - block_start; ASSERT(block_len <= U32_MAX); for (i = 0; i < num_pages; i++) { /* page checked is some magic around finding pages that * have been modified without going through btrfs_set_page_dirty * clear it here. There should be no need to mark the pages * accessed as prepare_pages should have marked them accessed * in prepare_pages via find_or_create_page() */ btrfs_folio_clamp_clear_checked(fs_info, page_folio(pages[i]), block_start, block_len); unlock_page(pages[i]); put_page(pages[i]); } } /* * After btrfs_copy_from_user(), update the following things for delalloc: * - Mark newly dirtied pages as DELALLOC in the io tree. * Used to advise which range is to be written back. * - Mark modified pages as Uptodate/Dirty and not needing COW fixup * - Update inode size for past EOF write */ int btrfs_dirty_pages(struct btrfs_inode *inode, struct page **pages, size_t num_pages, loff_t pos, size_t write_bytes, struct extent_state **cached, bool noreserve) { struct btrfs_fs_info *fs_info = inode->root->fs_info; int err = 0; int i; u64 num_bytes; u64 start_pos; u64 end_of_last_block; u64 end_pos = pos + write_bytes; loff_t isize = i_size_read(&inode->vfs_inode); unsigned int extra_bits = 0; if (write_bytes == 0) return 0; if (noreserve) extra_bits |= EXTENT_NORESERVE; start_pos = round_down(pos, fs_info->sectorsize); num_bytes = round_up(write_bytes + pos - start_pos, fs_info->sectorsize); ASSERT(num_bytes <= U32_MAX); end_of_last_block = start_pos + num_bytes - 1; /* * The pages may have already been dirty, clear out old accounting so * we can set things up properly */ clear_extent_bit(&inode->io_tree, start_pos, end_of_last_block, EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, cached); err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block, extra_bits, cached); if (err) return err; for (i = 0; i < num_pages; i++) { struct page *p = pages[i]; btrfs_folio_clamp_set_uptodate(fs_info, page_folio(p), start_pos, num_bytes); btrfs_folio_clamp_clear_checked(fs_info, page_folio(p), start_pos, num_bytes); btrfs_folio_clamp_set_dirty(fs_info, page_folio(p), start_pos, num_bytes); } /* * we've only changed i_size in ram, and we haven't updated * the disk i_size. There is no need to log the inode * at this time. */ if (end_pos > isize) i_size_write(&inode->vfs_inode, end_pos); return 0; } /* * this is very complex, but the basic idea is to drop all extents * in the range start - end. hint_block is filled in with a block number * that would be a good hint to the block allocator for this file. * * If an extent intersects the range but is not entirely inside the range * it is either truncated or split. Anything entirely inside the range * is deleted from the tree. * * Note: the VFS' inode number of bytes is not updated, it's up to the caller * to deal with that. We set the field 'bytes_found' of the arguments structure * with the number of allocated bytes found in the target range, so that the * caller can update the inode's number of bytes in an atomic way when * replacing extents in a range to avoid races with stat(2). */ int btrfs_drop_extents(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_inode *inode, struct btrfs_drop_extents_args *args) { struct btrfs_fs_info *fs_info = root->fs_info; struct extent_buffer *leaf; struct btrfs_file_extent_item *fi; struct btrfs_ref ref = { 0 }; struct btrfs_key key; struct btrfs_key new_key; u64 ino = btrfs_ino(inode); u64 search_start = args->start; u64 disk_bytenr = 0; u64 num_bytes = 0; u64 extent_offset = 0; u64 extent_end = 0; u64 last_end = args->start; int del_nr = 0; int del_slot = 0; int extent_type; int recow; int ret; int modify_tree = -1; int update_refs; int found = 0; struct btrfs_path *path = args->path; args->bytes_found = 0; args->extent_inserted = false; /* Must always have a path if ->replace_extent is true */ ASSERT(!(args->replace_extent && !args->path)); if (!path) { path = btrfs_alloc_path(); if (!path) { ret = -ENOMEM; goto out; } } if (args->drop_cache) btrfs_drop_extent_map_range(inode, args->start, args->end - 1, false); if (args->start >= inode->disk_i_size && !args->replace_extent) modify_tree = 0; update_refs = (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID); while (1) { recow = 0; ret = btrfs_lookup_file_extent(trans, root, path, ino, search_start, modify_tree); if (ret < 0) break; if (ret > 0 && path->slots[0] > 0 && search_start == args->start) { leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1); if (key.objectid == ino && key.type == BTRFS_EXTENT_DATA_KEY) path->slots[0]--; } ret = 0; next_slot: leaf = path->nodes[0]; if (path->slots[0] >= btrfs_header_nritems(leaf)) { BUG_ON(del_nr > 0); ret = btrfs_next_leaf(root, path); if (ret < 0) break; if (ret > 0) { ret = 0; break; } leaf = path->nodes[0]; recow = 1; } btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); if (key.objectid > ino) break; if (WARN_ON_ONCE(key.objectid < ino) || key.type < BTRFS_EXTENT_DATA_KEY) { ASSERT(del_nr == 0); path->slots[0]++; goto next_slot; } if (key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= args->end) break; fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); extent_type = btrfs_file_extent_type(leaf, fi); if (extent_type == BTRFS_FILE_EXTENT_REG || extent_type == BTRFS_FILE_EXTENT_PREALLOC) { disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi); extent_offset = btrfs_file_extent_offset(leaf, fi); extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi); } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { extent_end = key.offset + btrfs_file_extent_ram_bytes(leaf, fi); } else { /* can't happen */ BUG(); } /* * Don't skip extent items representing 0 byte lengths. They * used to be created (bug) if while punching holes we hit * -ENOSPC condition. So if we find one here, just ensure we * delete it, otherwise we would insert a new file extent item * with the same key (offset) as that 0 bytes length file * extent item in the call to setup_items_for_insert() later * in this function. */ if (extent_end == key.offset && extent_end >= search_start) { last_end = extent_end; goto delete_extent_item; } if (extent_end <= search_start) { path->slots[0]++; goto next_slot; } found = 1; search_start = max(key.offset, args->start); if (recow || !modify_tree) { modify_tree = -1; btrfs_release_path(path); continue; } /* * | - range to drop - | * | -------- extent -------- | */ if (args->start > key.offset && args->end < extent_end) { BUG_ON(del_nr > 0); if (extent_type == BTRFS_FILE_EXTENT_INLINE) { ret = -EOPNOTSUPP; break; } memcpy(&new_key, &key, sizeof(new_key)); new_key.offset = args->start; ret = btrfs_duplicate_item(trans, root, path, &new_key); if (ret == -EAGAIN) { btrfs_release_path(path); continue; } if (ret < 0) break; leaf = path->nodes[0]; fi = btrfs_item_ptr(leaf, path->slots[0] - 1, struct btrfs_file_extent_item); btrfs_set_file_extent_num_bytes(leaf, fi, args->start - key.offset); fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); extent_offset += args->start - key.offset; btrfs_set_file_extent_offset(leaf, fi, extent_offset); btrfs_set_file_extent_num_bytes(leaf, fi, extent_end - args->start); btrfs_mark_buffer_dirty(trans, leaf); if (update_refs && disk_bytenr > 0) { btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF, disk_bytenr, num_bytes, 0, root->root_key.objectid); btrfs_init_data_ref(&ref, root->root_key.objectid, new_key.objectid, args->start - extent_offset, 0, false); ret = btrfs_inc_extent_ref(trans, &ref); if (ret) { btrfs_abort_transaction(trans, ret); break; } } key.offset = args->start; } /* * From here on out we will have actually dropped something, so * last_end can be updated. */ last_end = extent_end; /* * | ---- range to drop ----- | * | -------- extent -------- | */ if (args->start <= key.offset && args->end < extent_end) { if (extent_type == BTRFS_FILE_EXTENT_INLINE) { ret = -EOPNOTSUPP; break; } memcpy(&new_key, &key, sizeof(new_key)); new_key.offset = args->end; btrfs_set_item_key_safe(trans, path, &new_key); extent_offset += args->end - key.offset; btrfs_set_file_extent_offset(leaf, fi, extent_offset); btrfs_set_file_extent_num_bytes(leaf, fi, extent_end - args->end); btrfs_mark_buffer_dirty(trans, leaf); if (update_refs && disk_bytenr > 0) args->bytes_found += args->end - key.offset; break; } search_start = extent_end; /* * | ---- range to drop ----- | * | -------- extent -------- | */ if (args->start > key.offset && args->end >= extent_end) { BUG_ON(del_nr > 0); if (extent_type == BTRFS_FILE_EXTENT_INLINE) { ret = -EOPNOTSUPP; break; } btrfs_set_file_extent_num_bytes(leaf, fi, args->start - key.offset); btrfs_mark_buffer_dirty(trans, leaf); if (update_refs && disk_bytenr > 0) args->bytes_found += extent_end - args->start; if (args->end == extent_end) break; path->slots[0]++; goto next_slot; } /* * | ---- range to drop ----- | * | ------ extent ------ | */ if (args->start <= key.offset && args->end >= extent_end) { delete_extent_item: if (del_nr == 0) { del_slot = path->slots[0]; del_nr = 1; } else { BUG_ON(del_slot + del_nr != path->slots[0]); del_nr++; } if (update_refs && extent_type == BTRFS_FILE_EXTENT_INLINE) { args->bytes_found += extent_end - key.offset; extent_end = ALIGN(extent_end, fs_info->sectorsize); } else if (update_refs && disk_bytenr > 0) { btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, disk_bytenr, num_bytes, 0, root->root_key.objectid); btrfs_init_data_ref(&ref, root->root_key.objectid, key.objectid, key.offset - extent_offset, 0, false); ret = btrfs_free_extent(trans, &ref); if (ret) { btrfs_abort_transaction(trans, ret); break; } args->bytes_found += extent_end - key.offset; } if (args->end == extent_end) break; if (path->slots[0] + 1 < btrfs_header_nritems(leaf)) { path->slots[0]++; goto next_slot; } ret = btrfs_del_items(trans, root, path, del_slot, del_nr); if (ret) { btrfs_abort_transaction(trans, ret); break; } del_nr = 0; del_slot = 0; btrfs_release_path(path); continue; } BUG(); } if (!ret && del_nr > 0) { /* * Set path->slots[0] to first slot, so that after the delete * if items are move off from our leaf to its immediate left or * right neighbor leafs, we end up with a correct and adjusted * path->slots[0] for our insertion (if args->replace_extent). */ path->slots[0] = del_slot; ret = btrfs_del_items(trans, root, path, del_slot, del_nr); if (ret) btrfs_abort_transaction(trans, ret); } leaf = path->nodes[0]; /* * If btrfs_del_items() was called, it might have deleted a leaf, in * which case it unlocked our path, so check path->locks[0] matches a * write lock. */ if (!ret && args->replace_extent && path->locks[0] == BTRFS_WRITE_LOCK && btrfs_leaf_free_space(leaf) >= sizeof(struct btrfs_item) + args->extent_item_size) { key.objectid = ino; key.type = BTRFS_EXTENT_DATA_KEY; key.offset = args->start; if (!del_nr && path->slots[0] < btrfs_header_nritems(leaf)) { struct btrfs_key slot_key; btrfs_item_key_to_cpu(leaf, &slot_key, path->slots[0]); if (btrfs_comp_cpu_keys(&key, &slot_key) > 0) path->slots[0]++; } btrfs_setup_item_for_insert(trans, root, path, &key, args->extent_item_size); args->extent_inserted = true; } if (!args->path) btrfs_free_path(path); else if (!args->extent_inserted) btrfs_release_path(path); out: args->drop_end = found ? min(args->end, last_end) : args->end; return ret; } static int extent_mergeable(struct extent_buffer *leaf, int slot, u64 objectid, u64 bytenr, u64 orig_offset, u64 *start, u64 *end) { struct btrfs_file_extent_item *fi; struct btrfs_key key; u64 extent_end; if (slot < 0 || slot >= btrfs_header_nritems(leaf)) return 0; btrfs_item_key_to_cpu(leaf, &key, slot); if (key.objectid != objectid || key.type != BTRFS_EXTENT_DATA_KEY) return 0; fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG || btrfs_file_extent_disk_bytenr(leaf, fi) != bytenr || btrfs_file_extent_offset(leaf, fi) != key.offset - orig_offset || btrfs_file_extent_compression(leaf, fi) || btrfs_file_extent_encryption(leaf, fi) || btrfs_file_extent_other_encoding(leaf, fi)) return 0; extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi); if ((*start && *start != key.offset) || (*end && *end != extent_end)) return 0; *start = key.offset; *end = extent_end; return 1; } /* * Mark extent in the range start - end as written. * * This changes extent type from 'pre-allocated' to 'regular'. If only * part of extent is marked as written, the extent will be split into * two or three. */ int btrfs_mark_extent_written(struct btrfs_trans_handle *trans, struct btrfs_inode *inode, u64 start, u64 end) { struct btrfs_root *root = inode->root; struct extent_buffer *leaf; struct btrfs_path *path; struct btrfs_file_extent_item *fi; struct btrfs_ref ref = { 0 }; struct btrfs_key key; struct btrfs_key new_key; u64 bytenr; u64 num_bytes; u64 extent_end; u64 orig_offset; u64 other_start; u64 other_end; u64 split; int del_nr = 0; int del_slot = 0; int recow; int ret = 0; u64 ino = btrfs_ino(inode); path = btrfs_alloc_path(); if (!path) return -ENOMEM; again: recow = 0; split = start; key.objectid = ino; key.type = BTRFS_EXTENT_DATA_KEY; key.offset = split; ret = btrfs_search_slot(trans, root, &key, path, -1, 1); if (ret < 0) goto out; if (ret > 0 && path->slots[0] > 0) path->slots[0]--; leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); if (key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY) { ret = -EINVAL; btrfs_abort_transaction(trans, ret); goto out; } fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_PREALLOC) { ret = -EINVAL; btrfs_abort_transaction(trans, ret); goto out; } extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi); if (key.offset > start || extent_end < end) { ret = -EINVAL; btrfs_abort_transaction(trans, ret); goto out; } bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi); orig_offset = key.offset - btrfs_file_extent_offset(leaf, fi); memcpy(&new_key, &key, sizeof(new_key)); if (start == key.offset && end < extent_end) { other_start = 0; other_end = start; if (extent_mergeable(leaf, path->slots[0] - 1, ino, bytenr, orig_offset, &other_start, &other_end)) { new_key.offset = end; btrfs_set_item_key_safe(trans, path, &new_key); fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); btrfs_set_file_extent_generation(leaf, fi, trans->transid); btrfs_set_file_extent_num_bytes(leaf, fi, extent_end - end); btrfs_set_file_extent_offset(leaf, fi, end - orig_offset); fi = btrfs_item_ptr(leaf, path->slots[0] - 1, struct btrfs_file_extent_item); btrfs_set_file_extent_generation(leaf, fi, trans->transid); btrfs_set_file_extent_num_bytes(leaf, fi, end - other_start); btrfs_mark_buffer_dirty(trans, leaf); goto out; } } if (start > key.offset && end == extent_end) { other_start = end; other_end = 0; if (extent_mergeable(leaf, path->slots[0] + 1, ino, bytenr, orig_offset, &other_start, &other_end)) { fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); btrfs_set_file_extent_num_bytes(leaf, fi, start - key.offset); btrfs_set_file_extent_generation(leaf, fi, trans->transid); path->slots[0]++; new_key.offset = start; btrfs_set_item_key_safe(trans, path, &new_key); fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); btrfs_set_file_extent_generation(leaf, fi, trans->transid); btrfs_set_file_extent_num_bytes(leaf, fi, other_end - start); btrfs_set_file_extent_offset(leaf, fi, start - orig_offset); btrfs_mark_buffer_dirty(trans, leaf); goto out; } } while (start > key.offset || end < extent_end) { if (key.offset == start) split = end; new_key.offset = split; ret = btrfs_duplicate_item(trans, root, path, &new_key); if (ret == -EAGAIN) { btrfs_release_path(path); goto again; } if (ret < 0) { btrfs_abort_transaction(trans, ret); goto out; } leaf = path->nodes[0]; fi = btrfs_item_ptr(leaf, path->slots[0] - 1, struct btrfs_file_extent_item); btrfs_set_file_extent_generation(leaf, fi, trans->transid); btrfs_set_file_extent_num_bytes(leaf, fi, split - key.offset); fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); btrfs_set_file_extent_generation(leaf, fi, trans->transid); btrfs_set_file_extent_offset(leaf, fi, split - orig_offset); btrfs_set_file_extent_num_bytes(leaf, fi, extent_end - split); btrfs_mark_buffer_dirty(trans, leaf); btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF, bytenr, num_bytes, 0, root->root_key.objectid); btrfs_init_data_ref(&ref, root->root_key.objectid, ino, orig_offset, 0, false); ret = btrfs_inc_extent_ref(trans, &ref); if (ret) { btrfs_abort_transaction(trans, ret); goto out; } if (split == start) { key.offset = start; } else { if (start != key.offset) { ret = -EINVAL; btrfs_abort_transaction(trans, ret); goto out; } path->slots[0]--; extent_end = end; } recow = 1; } other_start = end; other_end = 0; btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, bytenr, num_bytes, 0, root->root_key.objectid); btrfs_init_data_ref(&ref, root->root_key.objectid, ino, orig_offset, 0, false); if (extent_mergeable(leaf, path->slots[0] + 1, ino, bytenr, orig_offset, &other_start, &other_end)) { if (recow) { btrfs_release_path(path); goto again; } extent_end = other_end; del_slot = path->slots[0] + 1; del_nr++; ret = btrfs_free_extent(trans, &ref); if (ret) { btrfs_abort_transaction(trans, ret); goto out; } } other_start = 0; other_end = start; if (extent_mergeable(leaf, path->slots[0] - 1, ino, bytenr, orig_offset, &other_start, &other_end)) { if (recow) { btrfs_release_path(path); goto again; } key.offset = other_start; del_slot = path->slots[0]; del_nr++; ret = btrfs_free_extent(trans, &ref); if (ret) { btrfs_abort_transaction(trans, ret); goto out; } } if (del_nr == 0) { fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); btrfs_set_file_extent_type(leaf, fi, BTRFS_FILE_EXTENT_REG); btrfs_set_file_extent_generation(leaf, fi, trans->transid); btrfs_mark_buffer_dirty(trans, leaf); } else { fi = btrfs_item_ptr(leaf, del_slot - 1, struct btrfs_file_extent_item); btrfs_set_file_extent_type(leaf, fi, BTRFS_FILE_EXTENT_REG); btrfs_set_file_extent_generation(leaf, fi, trans->transid); btrfs_set_file_extent_num_bytes(leaf, fi, extent_end - key.offset); btrfs_mark_buffer_dirty(trans, leaf); ret = btrfs_del_items(trans, root, path, del_slot, del_nr); if (ret < 0) { btrfs_abort_transaction(trans, ret); goto out; } } out: btrfs_free_path(path); return ret; } /* * on error we return an unlocked page and the error value * on success we return a locked page and 0 */ static int prepare_uptodate_page(struct inode *inode, struct page *page, u64 pos, bool force_uptodate) { struct folio *folio = page_folio(page); int ret = 0; if (((pos & (PAGE_SIZE - 1)) || force_uptodate) && !PageUptodate(page)) { ret = btrfs_read_folio(NULL, folio); if (ret) return ret; lock_page(page); if (!PageUptodate(page)) { unlock_page(page); return -EIO; } /* * Since btrfs_read_folio() will unlock the folio before it * returns, there is a window where btrfs_release_folio() can be * called to release the page. Here we check both inode * mapping and PagePrivate() to make sure the page was not * released. * * The private flag check is essential for subpage as we need * to store extra bitmap using folio private. */ if (page->mapping != inode->i_mapping || !folio_test_private(folio)) { unlock_page(page); return -EAGAIN; } } return 0; } static fgf_t get_prepare_fgp_flags(bool nowait) { fgf_t fgp_flags = FGP_LOCK | FGP_ACCESSED | FGP_CREAT; if (nowait) fgp_flags |= FGP_NOWAIT; return fgp_flags; } static gfp_t get_prepare_gfp_flags(struct inode *inode, bool nowait) { gfp_t gfp; gfp = btrfs_alloc_write_mask(inode->i_mapping); if (nowait) { gfp &= ~__GFP_DIRECT_RECLAIM; gfp |= GFP_NOWAIT; } return gfp; } /* * this just gets pages into the page cache and locks them down. */ static noinline int prepare_pages(struct inode *inode, struct page **pages, size_t num_pages, loff_t pos, size_t write_bytes, bool force_uptodate, bool nowait) { int i; unsigned long index = pos >> PAGE_SHIFT; gfp_t mask = get_prepare_gfp_flags(inode, nowait); fgf_t fgp_flags = get_prepare_fgp_flags(nowait); int err = 0; int faili; for (i = 0; i < num_pages; i++) { again: pages[i] = pagecache_get_page(inode->i_mapping, index + i, fgp_flags, mask | __GFP_WRITE); if (!pages[i]) { faili = i - 1; if (nowait) err = -EAGAIN; else err = -ENOMEM; goto fail; } err = set_page_extent_mapped(pages[i]); if (err < 0) { faili = i; goto fail; } if (i == 0) err = prepare_uptodate_page(inode, pages[i], pos, force_uptodate); if (!err && i == num_pages - 1) err = prepare_uptodate_page(inode, pages[i], pos + write_bytes, false); if (err) { put_page(pages[i]); if (!nowait && err == -EAGAIN) { err = 0; goto again; } faili = i - 1; goto fail; } wait_on_page_writeback(pages[i]); } return 0; fail: while (faili >= 0) { unlock_page(pages[faili]); put_page(pages[faili]); faili--; } return err; } /* * This function locks the extent and properly waits for data=ordered extents * to finish before allowing the pages to be modified if need. * * The return value: * 1 - the extent is locked * 0 - the extent is not locked, and everything is OK * -EAGAIN - need re-prepare the pages * the other < 0 number - Something wrong happens */ static noinline int lock_and_cleanup_extent_if_need(struct btrfs_inode *inode, struct page **pages, size_t num_pages, loff_t pos, size_t write_bytes, u64 *lockstart, u64 *lockend, bool nowait, struct extent_state **cached_state) { struct btrfs_fs_info *fs_info = inode->root->fs_info; u64 start_pos; u64 last_pos; int i; int ret = 0; start_pos = round_down(pos, fs_info->sectorsize); last_pos = round_up(pos + write_bytes, fs_info->sectorsize) - 1; if (start_pos < inode->vfs_inode.i_size) { struct btrfs_ordered_extent *ordered; if (nowait) { if (!try_lock_extent(&inode->io_tree, start_pos, last_pos, cached_state)) { for (i = 0; i < num_pages; i++) { unlock_page(pages[i]); put_page(pages[i]); pages[i] = NULL; } return -EAGAIN; } } else { lock_extent(&inode->io_tree, start_pos, last_pos, cached_state); } ordered = btrfs_lookup_ordered_range(inode, start_pos, last_pos - start_pos + 1); if (ordered && ordered->file_offset + ordered->num_bytes > start_pos && ordered->file_offset <= last_pos) { unlock_extent(&inode->io_tree, start_pos, last_pos, cached_state); for (i = 0; i < num_pages; i++) { unlock_page(pages[i]); put_page(pages[i]); } btrfs_start_ordered_extent(ordered); btrfs_put_ordered_extent(ordered); return -EAGAIN; } if (ordered) btrfs_put_ordered_extent(ordered); *lockstart = start_pos; *lockend = last_pos; ret = 1; } /* * We should be called after prepare_pages() which should have locked * all pages in the range. */ for (i = 0; i < num_pages; i++) WARN_ON(!PageLocked(pages[i])); return ret; } /* * Check if we can do nocow write into the range [@pos, @pos + @write_bytes) * * @pos: File offset. * @write_bytes: The length to write, will be updated to the nocow writeable * range. * * This function will flush ordered extents in the range to ensure proper * nocow checks. * * Return: * > 0 If we can nocow, and updates @write_bytes. * 0 If we can't do a nocow write. * -EAGAIN If we can't do a nocow write because snapshoting of the inode's * root is in progress. * < 0 If an error happened. * * NOTE: Callers need to call btrfs_check_nocow_unlock() if we return > 0. */ int btrfs_check_nocow_lock(struct btrfs_inode *inode, loff_t pos, size_t *write_bytes, bool nowait) { struct btrfs_fs_info *fs_info = inode->root->fs_info; struct btrfs_root *root = inode->root; struct extent_state *cached_state = NULL; u64 lockstart, lockend; u64 num_bytes; int ret; if (!(inode->flags & (BTRFS_INODE_NODATACOW | BTRFS_INODE_PREALLOC))) return 0; if (!btrfs_drew_try_write_lock(&root->snapshot_lock)) return -EAGAIN; lockstart = round_down(pos, fs_info->sectorsize); lockend = round_up(pos + *write_bytes, fs_info->sectorsize) - 1; num_bytes = lockend - lockstart + 1; if (nowait) { if (!btrfs_try_lock_ordered_range(inode, lockstart, lockend, &cached_state)) { btrfs_drew_write_unlock(&root->snapshot_lock); return -EAGAIN; } } else { btrfs_lock_and_flush_ordered_range(inode, lockstart, lockend, &cached_state); } ret = can_nocow_extent(&inode->vfs_inode, lockstart, &num_bytes, NULL, NULL, NULL, nowait, false); if (ret <= 0) btrfs_drew_write_unlock(&root->snapshot_lock); else *write_bytes = min_t(size_t, *write_bytes , num_bytes - pos + lockstart); unlock_extent(&inode->io_tree, lockstart, lockend, &cached_state); return ret; } void btrfs_check_nocow_unlock(struct btrfs_inode *inode) { btrfs_drew_write_unlock(&inode->root->snapshot_lock); } static void update_time_for_write(struct inode *inode) { struct timespec64 now, ts; if (IS_NOCMTIME(inode)) return; now = current_time(inode); ts = inode_get_mtime(inode); if (!timespec64_equal(&ts, &now)) inode_set_mtime_to_ts(inode, now); ts = inode_get_ctime(inode); if (!timespec64_equal(&ts, &now)) inode_set_ctime_to_ts(inode, now); if (IS_I_VERSION(inode)) inode_inc_iversion(inode); } static int btrfs_write_check(struct kiocb *iocb, struct iov_iter *from, size_t count) { struct file *file = iocb->ki_filp; struct inode *inode = file_inode(file); struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); loff_t pos = iocb->ki_pos; int ret; loff_t oldsize; loff_t start_pos; /* * Quickly bail out on NOWAIT writes if we don't have the nodatacow or * prealloc flags, as without those flags we always have to COW. We will * later check if we can really COW into the target range (using * can_nocow_extent() at btrfs_get_blocks_direct_write()). */ if ((iocb->ki_flags & IOCB_NOWAIT) && !(BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW | BTRFS_INODE_PREALLOC))) return -EAGAIN; ret = file_remove_privs(file); if (ret) return ret; /* * We reserve space for updating the inode when we reserve space for the * extent we are going to write, so we will enospc out there. We don't * need to start yet another transaction to update the inode as we will * update the inode when we finish writing whatever data we write. */ update_time_for_write(inode); start_pos = round_down(pos, fs_info->sectorsize); oldsize = i_size_read(inode); if (start_pos > oldsize) { /* Expand hole size to cover write data, preventing empty gap */ loff_t end_pos = round_up(pos + count, fs_info->sectorsize); ret = btrfs_cont_expand(BTRFS_I(inode), oldsize, end_pos); if (ret) return ret; } return 0; } static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) { struct file *file = iocb->ki_filp; loff_t pos; struct inode *inode = file_inode(file); struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); struct page **pages = NULL; struct extent_changeset *data_reserved = NULL; u64 release_bytes = 0; u64 lockstart; u64 lockend; size_t num_written = 0; int nrptrs; ssize_t ret; bool only_release_metadata = false; bool force_page_uptodate = false; loff_t old_isize = i_size_read(inode); unsigned int ilock_flags = 0; const bool nowait = (iocb->ki_flags & IOCB_NOWAIT); unsigned int bdp_flags = (nowait ? BDP_ASYNC : 0); if (nowait) ilock_flags |= BTRFS_ILOCK_TRY; ret = btrfs_inode_lock(BTRFS_I(inode), ilock_flags); if (ret < 0) return ret; ret = generic_write_checks(iocb, i); if (ret <= 0) goto out; ret = btrfs_write_check(iocb, i, ret); if (ret < 0) goto out; pos = iocb->ki_pos; nrptrs = min(DIV_ROUND_UP(iov_iter_count(i), PAGE_SIZE), PAGE_SIZE / (sizeof(struct page *))); nrptrs = min(nrptrs, current->nr_dirtied_pause - current->nr_dirtied); nrptrs = max(nrptrs, 8); pages = kmalloc_array(nrptrs, sizeof(struct page *), GFP_KERNEL); if (!pages) { ret = -ENOMEM; goto out; } while (iov_iter_count(i) > 0) { struct extent_state *cached_state = NULL; size_t offset = offset_in_page(pos); size_t sector_offset; size_t write_bytes = min(iov_iter_count(i), nrptrs * (size_t)PAGE_SIZE - offset); size_t num_pages; size_t reserve_bytes; size_t dirty_pages; size_t copied; size_t dirty_sectors; size_t num_sectors; int extents_locked; /* * Fault pages before locking them in prepare_pages * to avoid recursive lock */ if (unlikely(fault_in_iov_iter_readable(i, write_bytes))) { ret = -EFAULT; break; } only_release_metadata = false; sector_offset = pos & (fs_info->sectorsize - 1); extent_changeset_release(data_reserved); ret = btrfs_check_data_free_space(BTRFS_I(inode), &data_reserved, pos, write_bytes, nowait); if (ret < 0) { int can_nocow; if (nowait && (ret == -ENOSPC || ret == -EAGAIN)) { ret = -EAGAIN; break; } /* * If we don't have to COW at the offset, reserve * metadata only. write_bytes may get smaller than * requested here. */ can_nocow = btrfs_check_nocow_lock(BTRFS_I(inode), pos, &write_bytes, nowait); if (can_nocow < 0) ret = can_nocow; if (can_nocow > 0) ret = 0; if (ret) break; only_release_metadata = true; } num_pages = DIV_ROUND_UP(write_bytes + offset, PAGE_SIZE); WARN_ON(num_pages > nrptrs); reserve_bytes = round_up(write_bytes + sector_offset, fs_info->sectorsize); WARN_ON(reserve_bytes == 0); ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode), reserve_bytes, reserve_bytes, nowait); if (ret) { if (!only_release_metadata) btrfs_free_reserved_data_space(BTRFS_I(inode), data_reserved, pos, write_bytes); else btrfs_check_nocow_unlock(BTRFS_I(inode)); if (nowait && ret == -ENOSPC) ret = -EAGAIN; break; } release_bytes = reserve_bytes; again: ret = balance_dirty_pages_ratelimited_flags(inode->i_mapping, bdp_flags); if (ret) { btrfs_delalloc_release_extents(BTRFS_I(inode), reserve_bytes); break; } /* * This is going to setup the pages array with the number of * pages we want, so we don't really need to worry about the * contents of pages from loop to loop */ ret = prepare_pages(inode, pages, num_pages, pos, write_bytes, force_page_uptodate, false); if (ret) { btrfs_delalloc_release_extents(BTRFS_I(inode), reserve_bytes); break; } extents_locked = lock_and_cleanup_extent_if_need( BTRFS_I(inode), pages, num_pages, pos, write_bytes, &lockstart, &lockend, nowait, &cached_state); if (extents_locked < 0) { if (!nowait && extents_locked == -EAGAIN) goto again; btrfs_delalloc_release_extents(BTRFS_I(inode), reserve_bytes); ret = extents_locked; break; } copied = btrfs_copy_from_user(pos, write_bytes, pages, i); num_sectors = BTRFS_BYTES_TO_BLKS(fs_info, reserve_bytes); dirty_sectors = round_up(copied + sector_offset, fs_info->sectorsize); dirty_sectors = BTRFS_BYTES_TO_BLKS(fs_info, dirty_sectors); /* * if we have trouble faulting in the pages, fall * back to one page at a time */ if (copied < write_bytes) nrptrs = 1; if (copied == 0) { force_page_uptodate = true; dirty_sectors = 0; dirty_pages = 0; } else { force_page_uptodate = false; dirty_pages = DIV_ROUND_UP(copied + offset, PAGE_SIZE); } if (num_sectors > dirty_sectors) { /* release everything except the sectors we dirtied */ release_bytes -= dirty_sectors << fs_info->sectorsize_bits; if (only_release_metadata) { btrfs_delalloc_release_metadata(BTRFS_I(inode), release_bytes, true); } else { u64 __pos; __pos = round_down(pos, fs_info->sectorsize) + (dirty_pages << PAGE_SHIFT); btrfs_delalloc_release_space(BTRFS_I(inode), data_reserved, __pos, release_bytes, true); } } release_bytes = round_up(copied + sector_offset, fs_info->sectorsize); ret = btrfs_dirty_pages(BTRFS_I(inode), pages, dirty_pages, pos, copied, &cached_state, only_release_metadata); /* * If we have not locked the extent range, because the range's * start offset is >= i_size, we might still have a non-NULL * cached extent state, acquired while marking the extent range * as delalloc through btrfs_dirty_pages(). Therefore free any * possible cached extent state to avoid a memory leak. */ if (extents_locked) unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend, &cached_state); else free_extent_state(cached_state); btrfs_delalloc_release_extents(BTRFS_I(inode), reserve_bytes); if (ret) { btrfs_drop_pages(fs_info, pages, num_pages, pos, copied); break; } release_bytes = 0; if (only_release_metadata) btrfs_check_nocow_unlock(BTRFS_I(inode)); btrfs_drop_pages(fs_info, pages, num_pages, pos, copied); cond_resched(); pos += copied; num_written += copied; } kfree(pages); if (release_bytes) { if (only_release_metadata) { btrfs_check_nocow_unlock(BTRFS_I(inode)); btrfs_delalloc_release_metadata(BTRFS_I(inode), release_bytes, true); } else { btrfs_delalloc_release_space(BTRFS_I(inode), data_reserved, round_down(pos, fs_info->sectorsize), release_bytes, true); } } extent_changeset_free(data_reserved); if (num_written > 0) { pagecache_isize_extended(inode, old_isize, iocb->ki_pos); iocb->ki_pos += num_written; } out: btrfs_inode_unlock(BTRFS_I(inode), ilock_flags); return num_written ? num_written : ret; } static ssize_t check_direct_IO(struct btrfs_fs_info *fs_info, const struct iov_iter *iter, loff_t offset) { const u32 blocksize_mask = fs_info->sectorsize - 1; if (offset & blocksize_mask) return -EINVAL; if (iov_iter_alignment(iter) & blocksize_mask) return -EINVAL; return 0; } static ssize_t btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from) { struct file *file = iocb->ki_filp; struct inode *inode = file_inode(file); struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); loff_t pos; ssize_t written = 0; ssize_t written_buffered; size_t prev_left = 0; loff_t endbyte; ssize_t err; unsigned int ilock_flags = 0; struct iomap_dio *dio; if (iocb->ki_flags & IOCB_NOWAIT) ilock_flags |= BTRFS_ILOCK_TRY; /* * If the write DIO is within EOF, use a shared lock and also only if * security bits will likely not be dropped by file_remove_privs() called * from btrfs_write_check(). Either will need to be rechecked after the * lock was acquired. */ if (iocb->ki_pos + iov_iter_count(from) <= i_size_read(inode) && IS_NOSEC(inode)) ilock_flags |= BTRFS_ILOCK_SHARED; relock: err = btrfs_inode_lock(BTRFS_I(inode), ilock_flags); if (err < 0) return err; /* Shared lock cannot be used with security bits set. */ if ((ilock_flags & BTRFS_ILOCK_SHARED) && !IS_NOSEC(inode)) { btrfs_inode_unlock(BTRFS_I(inode), ilock_flags); ilock_flags &= ~BTRFS_ILOCK_SHARED; goto relock; } err = generic_write_checks(iocb, from); if (err <= 0) { btrfs_inode_unlock(BTRFS_I(inode), ilock_flags); return err; } err = btrfs_write_check(iocb, from, err); if (err < 0) { btrfs_inode_unlock(BTRFS_I(inode), ilock_flags); goto out; } pos = iocb->ki_pos; /* * Re-check since file size may have changed just before taking the * lock or pos may have changed because of O_APPEND in generic_write_check() */ if ((ilock_flags & BTRFS_ILOCK_SHARED) && pos + iov_iter_count(from) > i_size_read(inode)) { btrfs_inode_unlock(BTRFS_I(inode), ilock_flags); ilock_flags &= ~BTRFS_ILOCK_SHARED; goto relock; } if (check_direct_IO(fs_info, from, pos)) { btrfs_inode_unlock(BTRFS_I(inode), ilock_flags); goto buffered; } /* * The iov_iter can be mapped to the same file range we are writing to. * If that's the case, then we will deadlock in the iomap code, because * it first calls our callback btrfs_dio_iomap_begin(), which will create * an ordered extent, and after that it will fault in the pages that the * iov_iter refers to. During the fault in we end up in the readahead * pages code (starting at btrfs_readahead()), which will lock the range, * find that ordered extent and then wait for it to complete (at * btrfs_lock_and_flush_ordered_range()), resulting in a deadlock since * obviously the ordered extent can never complete as we didn't submit * yet the respective bio(s). This always happens when the buffer is * memory mapped to the same file range, since the iomap DIO code always * invalidates pages in the target file range (after starting and waiting * for any writeback). * * So here we disable page faults in the iov_iter and then retry if we * got -EFAULT, faulting in the pages before the retry. */ from->nofault = true; dio = btrfs_dio_write(iocb, from, written); from->nofault = false; /* * iomap_dio_complete() will call btrfs_sync_file() if we have a dsync * iocb, and that needs to lock the inode. So unlock it before calling * iomap_dio_complete() to avoid a deadlock. */ btrfs_inode_unlock(BTRFS_I(inode), ilock_flags); if (IS_ERR_OR_NULL(dio)) err = PTR_ERR_OR_ZERO(dio); else err = iomap_dio_complete(dio); /* No increment (+=) because iomap returns a cumulative value. */ if (err > 0) written = err; if (iov_iter_count(from) > 0 && (err == -EFAULT || err > 0)) { const size_t left = iov_iter_count(from); /* * We have more data left to write. Try to fault in as many as * possible of the remainder pages and retry. We do this without * releasing and locking again the inode, to prevent races with * truncate. * * Also, in case the iov refers to pages in the file range of the * file we want to write to (due to a mmap), we could enter an * infinite loop if we retry after faulting the pages in, since * iomap will invalidate any pages in the range early on, before * it tries to fault in the pages of the iov. So we keep track of * how much was left of iov in the previous EFAULT and fallback * to buffered IO in case we haven't made any progress. */ if (left == prev_left) { err = -ENOTBLK; } else { fault_in_iov_iter_readable(from, left); prev_left = left; goto relock; } } /* * If 'err' is -ENOTBLK or we have not written all data, then it means * we must fallback to buffered IO. */ if ((err < 0 && err != -ENOTBLK) || !iov_iter_count(from)) goto out; buffered: /* * If we are in a NOWAIT context, then return -EAGAIN to signal the caller * it must retry the operation in a context where blocking is acceptable, * because even if we end up not blocking during the buffered IO attempt * below, we will block when flushing and waiting for the IO. */ if (iocb->ki_flags & IOCB_NOWAIT) { err = -EAGAIN; goto out; } pos = iocb->ki_pos; written_buffered = btrfs_buffered_write(iocb, from); if (written_buffered < 0) { err = written_buffered; goto out; } /* * Ensure all data is persisted. We want the next direct IO read to be * able to read what was just written. */ endbyte = pos + written_buffered - 1; err = btrfs_fdatawrite_range(inode, pos, endbyte); if (err) goto out; err = filemap_fdatawait_range(inode->i_mapping, pos, endbyte); if (err) goto out; written += written_buffered; iocb->ki_pos = pos + written_buffered; invalidate_mapping_pages(file->f_mapping, pos >> PAGE_SHIFT, endbyte >> PAGE_SHIFT); out: return err < 0 ? err : written; } static ssize_t btrfs_encoded_write(struct kiocb *iocb, struct iov_iter *from, const struct btrfs_ioctl_encoded_io_args *encoded) { struct file *file = iocb->ki_filp; struct inode *inode = file_inode(file); loff_t count; ssize_t ret; btrfs_inode_lock(BTRFS_I(inode), 0); count = encoded->len; ret = generic_write_checks_count(iocb, &count); if (ret == 0 && count != encoded->len) { /* * The write got truncated by generic_write_checks_count(). We * can't do a partial encoded write. */ ret = -EFBIG; } if (ret || encoded->len == 0) goto out; ret = btrfs_write_check(iocb, from, encoded->len); if (ret < 0) goto out; ret = btrfs_do_encoded_write(iocb, from, encoded); out: btrfs_inode_unlock(BTRFS_I(inode), 0); return ret; } ssize_t btrfs_do_write_iter(struct kiocb *iocb, struct iov_iter *from, const struct btrfs_ioctl_encoded_io_args *encoded) { struct file *file = iocb->ki_filp; struct btrfs_inode *inode = BTRFS_I(file_inode(file)); ssize_t num_written, num_sync; /* * If the fs flips readonly due to some impossible error, although we * have opened a file as writable, we have to stop this write operation * to ensure consistency. */ if (BTRFS_FS_ERROR(inode->root->fs_info)) return -EROFS; if (encoded && (iocb->ki_flags & IOCB_NOWAIT)) return -EOPNOTSUPP; if (encoded) { num_written = btrfs_encoded_write(iocb, from, encoded); num_sync = encoded->len; } else if (iocb->ki_flags & IOCB_DIRECT) { num_written = btrfs_direct_write(iocb, from); num_sync = num_written; } else { num_written = btrfs_buffered_write(iocb, from); num_sync = num_written; } btrfs_set_inode_last_sub_trans(inode); if (num_sync > 0) { num_sync = generic_write_sync(iocb, num_sync); if (num_sync < 0) num_written = num_sync; } return num_written; } static ssize_t btrfs_file_write_iter(struct kiocb *iocb, struct iov_iter *from) { return btrfs_do_write_iter(iocb, from, NULL); } int btrfs_release_file(struct inode *inode, struct file *filp) { struct btrfs_file_private *private = filp->private_data; if (private) { kfree(private->filldir_buf); free_extent_state(private->llseek_cached_state); kfree(private); filp->private_data = NULL; } /* * Set by setattr when we are about to truncate a file from a non-zero * size to a zero size. This tries to flush down new bytes that may * have been written if the application were using truncate to replace * a file in place. */ if (test_and_clear_bit(BTRFS_INODE_FLUSH_ON_CLOSE, &BTRFS_I(inode)->runtime_flags)) filemap_flush(inode->i_mapping); return 0; } static int start_ordered_ops(struct inode *inode, loff_t start, loff_t end) { int ret; struct blk_plug plug; /* * This is only called in fsync, which would do synchronous writes, so * a plug can merge adjacent IOs as much as possible. Esp. in case of * multiple disks using raid profile, a large IO can be split to * several segments of stripe length (currently 64K). */ blk_start_plug(&plug); ret = btrfs_fdatawrite_range(inode, start, end); blk_finish_plug(&plug); return ret; } static inline bool skip_inode_logging(const struct btrfs_log_ctx *ctx) { struct btrfs_inode *inode = BTRFS_I(ctx->inode); struct btrfs_fs_info *fs_info = inode->root->fs_info; if (btrfs_inode_in_log(inode, btrfs_get_fs_generation(fs_info)) && list_empty(&ctx->ordered_extents)) return true; /* * If we are doing a fast fsync we can not bail out if the inode's * last_trans is <= then the last committed transaction, because we only * update the last_trans of the inode during ordered extent completion, * and for a fast fsync we don't wait for that, we only wait for the * writeback to complete. */ if (inode->last_trans <= btrfs_get_last_trans_committed(fs_info) && (test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags) || list_empty(&ctx->ordered_extents))) return true; return false; } /* * fsync call for both files and directories. This logs the inode into * the tree log instead of forcing full commits whenever possible. * * It needs to call filemap_fdatawait so that all ordered extent updates are * in the metadata btree are up to date for copying to the log. * * It drops the inode mutex before doing the tree log commit. This is an * important optimization for directories because holding the mutex prevents * new operations on the dir while we write to disk. */ int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync) { struct dentry *dentry = file_dentry(file); struct inode *inode = d_inode(dentry); struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_trans_handle *trans; struct btrfs_log_ctx ctx; int ret = 0, err; u64 len; bool full_sync; trace_btrfs_sync_file(file, datasync); btrfs_init_log_ctx(&ctx, inode); /* * Always set the range to a full range, otherwise we can get into * several problems, from missing file extent items to represent holes * when not using the NO_HOLES feature, to log tree corruption due to * races between hole detection during logging and completion of ordered * extents outside the range, to missing checksums due to ordered extents * for which we flushed only a subset of their pages. */ start = 0; end = LLONG_MAX; len = (u64)LLONG_MAX + 1; /* * We write the dirty pages in the range and wait until they complete * out of the ->i_mutex. If so, we can flush the dirty pages by * multi-task, and make the performance up. See * btrfs_wait_ordered_range for an explanation of the ASYNC check. */ ret = start_ordered_ops(inode, start, end); if (ret) goto out; btrfs_inode_lock(BTRFS_I(inode), BTRFS_ILOCK_MMAP); atomic_inc(&root->log_batch); /* * Before we acquired the inode's lock and the mmap lock, someone may * have dirtied more pages in the target range. We need to make sure * that writeback for any such pages does not start while we are logging * the inode, because if it does, any of the following might happen when * we are not doing a full inode sync: * * 1) We log an extent after its writeback finishes but before its * checksums are added to the csum tree, leading to -EIO errors * when attempting to read the extent after a log replay. * * 2) We can end up logging an extent before its writeback finishes. * Therefore after the log replay we will have a file extent item * pointing to an unwritten extent (and no data checksums as well). * * So trigger writeback for any eventual new dirty pages and then we * wait for all ordered extents to complete below. */ ret = start_ordered_ops(inode, start, end); if (ret) { btrfs_inode_unlock(BTRFS_I(inode), BTRFS_ILOCK_MMAP); goto out; } /* * Always check for the full sync flag while holding the inode's lock, * to avoid races with other tasks. The flag must be either set all the * time during logging or always off all the time while logging. * We check the flag here after starting delalloc above, because when * running delalloc the full sync flag may be set if we need to drop * extra extent map ranges due to temporary memory allocation failures. */ full_sync = test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); /* * We have to do this here to avoid the priority inversion of waiting on * IO of a lower priority task while holding a transaction open. * * For a full fsync we wait for the ordered extents to complete while * for a fast fsync we wait just for writeback to complete, and then * attach the ordered extents to the transaction so that a transaction * commit waits for their completion, to avoid data loss if we fsync, * the current transaction commits before the ordered extents complete * and a power failure happens right after that. * * For zoned filesystem, if a write IO uses a ZONE_APPEND command, the * logical address recorded in the ordered extent may change. We need * to wait for the IO to stabilize the logical address. */ if (full_sync || btrfs_is_zoned(fs_info)) { ret = btrfs_wait_ordered_range(inode, start, len); } else { /* * Get our ordered extents as soon as possible to avoid doing * checksum lookups in the csum tree, and use instead the * checksums attached to the ordered extents. */ btrfs_get_ordered_extents_for_logging(BTRFS_I(inode), &ctx.ordered_extents); ret = filemap_fdatawait_range(inode->i_mapping, start, end); } if (ret) goto out_release_extents; atomic_inc(&root->log_batch); if (skip_inode_logging(&ctx)) { /* * We've had everything committed since the last time we were * modified so clear this flag in case it was set for whatever * reason, it's no longer relevant. */ clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); /* * An ordered extent might have started before and completed * already with io errors, in which case the inode was not * updated and we end up here. So check the inode's mapping * for any errors that might have happened since we last * checked called fsync. */ ret = filemap_check_wb_err(inode->i_mapping, file->f_wb_err); goto out_release_extents; } /* * We use start here because we will need to wait on the IO to complete * in btrfs_sync_log, which could require joining a transaction (for * example checking cross references in the nocow path). If we use join * here we could get into a situation where we're waiting on IO to * happen that is blocked on a transaction trying to commit. With start * we inc the extwriter counter, so we wait for all extwriters to exit * before we start blocking joiners. This comment is to keep somebody * from thinking they are super smart and changing this to * btrfs_join_transaction *cough*Josef*cough*. */ trans = btrfs_start_transaction(root, 0); if (IS_ERR(trans)) { ret = PTR_ERR(trans); goto out_release_extents; } trans->in_fsync = true; ret = btrfs_log_dentry_safe(trans, dentry, &ctx); btrfs_release_log_ctx_extents(&ctx); if (ret < 0) { /* Fallthrough and commit/free transaction. */ ret = BTRFS_LOG_FORCE_COMMIT; } /* we've logged all the items and now have a consistent * version of the file in the log. It is possible that * someone will come in and modify the file, but that's * fine because the log is consistent on disk, and we * have references to all of the file's extents * * It is possible that someone will come in and log the * file again, but that will end up using the synchronization * inside btrfs_sync_log to keep things safe. */ btrfs_inode_unlock(BTRFS_I(inode), BTRFS_ILOCK_MMAP); if (ret == BTRFS_NO_LOG_SYNC) { ret = btrfs_end_transaction(trans); goto out; } /* We successfully logged the inode, attempt to sync the log. */ if (!ret) { ret = btrfs_sync_log(trans, root, &ctx); if (!ret) { ret = btrfs_end_transaction(trans); goto out; } } /* * At this point we need to commit the transaction because we had * btrfs_need_log_full_commit() or some other error. * * If we didn't do a full sync we have to stop the trans handle, wait on * the ordered extents, start it again and commit the transaction. If * we attempt to wait on the ordered extents here we could deadlock with * something like fallocate() that is holding the extent lock trying to * start a transaction while some other thread is trying to commit the * transaction while we (fsync) are currently holding the transaction * open. */ if (!full_sync) { ret = btrfs_end_transaction(trans); if (ret) goto out; ret = btrfs_wait_ordered_range(inode, start, len); if (ret) goto out; /* * This is safe to use here because we're only interested in * making sure the transaction that had the ordered extents is * committed. We aren't waiting on anything past this point, * we're purely getting the transaction and committing it. */ trans = btrfs_attach_transaction_barrier(root); if (IS_ERR(trans)) { ret = PTR_ERR(trans); /* * We committed the transaction and there's no currently * running transaction, this means everything we care * about made it to disk and we are done. */ if (ret == -ENOENT) ret = 0; goto out; } } ret = btrfs_commit_transaction(trans); out: ASSERT(list_empty(&ctx.list)); ASSERT(list_empty(&ctx.conflict_inodes)); err = file_check_and_advance_wb_err(file); if (!ret) ret = err; return ret > 0 ? -EIO : ret; out_release_extents: btrfs_release_log_ctx_extents(&ctx); btrfs_inode_unlock(BTRFS_I(inode), BTRFS_ILOCK_MMAP); goto out; } static const struct vm_operations_struct btrfs_file_vm_ops = { .fault = filemap_fault, .map_pages = filemap_map_pages, .page_mkwrite = btrfs_page_mkwrite, }; static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma) { struct address_space *mapping = filp->f_mapping; if (!mapping->a_ops->read_folio) return -ENOEXEC; file_accessed(filp); vma->vm_ops = &btrfs_file_vm_ops; return 0; } static int hole_mergeable(struct btrfs_inode *inode, struct extent_buffer *leaf, int slot, u64 start, u64 end) { struct btrfs_file_extent_item *fi; struct btrfs_key key; if (slot < 0 || slot >= btrfs_header_nritems(leaf)) return 0; btrfs_item_key_to_cpu(leaf, &key, slot); if (key.objectid != btrfs_ino(inode) || key.type != BTRFS_EXTENT_DATA_KEY) return 0; fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG) return 0; if (btrfs_file_extent_disk_bytenr(leaf, fi)) return 0; if (key.offset == end) return 1; if (key.offset + btrfs_file_extent_num_bytes(leaf, fi) == start) return 1; return 0; } static int fill_holes(struct btrfs_trans_handle *trans, struct btrfs_inode *inode, struct btrfs_path *path, u64 offset, u64 end) { struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_root *root = inode->root; struct extent_buffer *leaf; struct btrfs_file_extent_item *fi; struct extent_map *hole_em; struct btrfs_key key; int ret; if (btrfs_fs_incompat(fs_info, NO_HOLES)) goto out; key.objectid = btrfs_ino(inode); key.type = BTRFS_EXTENT_DATA_KEY; key.offset = offset; ret = btrfs_search_slot(trans, root, &key, path, 0, 1); if (ret <= 0) { /* * We should have dropped this offset, so if we find it then * something has gone horribly wrong. */ if (ret == 0) ret = -EINVAL; return ret; } leaf = path->nodes[0]; if (hole_mergeable(inode, leaf, path->slots[0] - 1, offset, end)) { u64 num_bytes; path->slots[0]--; fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); num_bytes = btrfs_file_extent_num_bytes(leaf, fi) + end - offset; btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes); btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes); btrfs_set_file_extent_offset(leaf, fi, 0); btrfs_set_file_extent_generation(leaf, fi, trans->transid); btrfs_mark_buffer_dirty(trans, leaf); goto out; } if (hole_mergeable(inode, leaf, path->slots[0], offset, end)) { u64 num_bytes; key.offset = offset; btrfs_set_item_key_safe(trans, path, &key); fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); num_bytes = btrfs_file_extent_num_bytes(leaf, fi) + end - offset; btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes); btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes); btrfs_set_file_extent_offset(leaf, fi, 0); btrfs_set_file_extent_generation(leaf, fi, trans->transid); btrfs_mark_buffer_dirty(trans, leaf); goto out; } btrfs_release_path(path); ret = btrfs_insert_hole_extent(trans, root, btrfs_ino(inode), offset, end - offset); if (ret) return ret; out: btrfs_release_path(path); hole_em = alloc_extent_map(); if (!hole_em) { btrfs_drop_extent_map_range(inode, offset, end - 1, false); btrfs_set_inode_full_sync(inode); } else { hole_em->start = offset; hole_em->len = end - offset; hole_em->ram_bytes = hole_em->len; hole_em->orig_start = offset; hole_em->block_start = EXTENT_MAP_HOLE; hole_em->block_len = 0; hole_em->orig_block_len = 0; hole_em->generation = trans->transid; ret = btrfs_replace_extent_map_range(inode, hole_em, true); free_extent_map(hole_em); if (ret) btrfs_set_inode_full_sync(inode); } return 0; } /* * Find a hole extent on given inode and change start/len to the end of hole * extent.(hole/vacuum extent whose em->start <= start && * em->start + em->len > start) * When a hole extent is found, return 1 and modify start/len. */ static int find_first_non_hole(struct btrfs_inode *inode, u64 *start, u64 *len) { struct btrfs_fs_info *fs_info = inode->root->fs_info; struct extent_map *em; int ret = 0; em = btrfs_get_extent(inode, NULL, 0, round_down(*start, fs_info->sectorsize), round_up(*len, fs_info->sectorsize)); if (IS_ERR(em)) return PTR_ERR(em); /* Hole or vacuum extent(only exists in no-hole mode) */ if (em->block_start == EXTENT_MAP_HOLE) { ret = 1; *len = em->start + em->len > *start + *len ? 0 : *start + *len - em->start - em->len; *start = em->start + em->len; } free_extent_map(em); return ret; } static void btrfs_punch_hole_lock_range(struct inode *inode, const u64 lockstart, const u64 lockend, struct extent_state **cached_state) { /* * For subpage case, if the range is not at page boundary, we could * have pages at the leading/tailing part of the range. * This could lead to dead loop since filemap_range_has_page() * will always return true. * So here we need to do extra page alignment for * filemap_range_has_page(). */ const u64 page_lockstart = round_up(lockstart, PAGE_SIZE); const u64 page_lockend = round_down(lockend + 1, PAGE_SIZE) - 1; while (1) { truncate_pagecache_range(inode, lockstart, lockend); lock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend, cached_state); /* * We can't have ordered extents in the range, nor dirty/writeback * pages, because we have locked the inode's VFS lock in exclusive * mode, we have locked the inode's i_mmap_lock in exclusive mode, * we have flushed all delalloc in the range and we have waited * for any ordered extents in the range to complete. * We can race with anyone reading pages from this range, so after * locking the range check if we have pages in the range, and if * we do, unlock the range and retry. */ if (!filemap_range_has_page(inode->i_mapping, page_lockstart, page_lockend)) break; unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend, cached_state); } btrfs_assert_inode_range_clean(BTRFS_I(inode), lockstart, lockend); } static int btrfs_insert_replace_extent(struct btrfs_trans_handle *trans, struct btrfs_inode *inode, struct btrfs_path *path, struct btrfs_replace_extent_info *extent_info, const u64 replace_len, const u64 bytes_to_drop) { struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_root *root = inode->root; struct btrfs_file_extent_item *extent; struct extent_buffer *leaf; struct btrfs_key key; int slot; struct btrfs_ref ref = { 0 }; int ret; if (replace_len == 0) return 0; if (extent_info->disk_offset == 0 && btrfs_fs_incompat(fs_info, NO_HOLES)) { btrfs_update_inode_bytes(inode, 0, bytes_to_drop); return 0; } key.objectid = btrfs_ino(inode); key.type = BTRFS_EXTENT_DATA_KEY; key.offset = extent_info->file_offset; ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(struct btrfs_file_extent_item)); if (ret) return ret; leaf = path->nodes[0]; slot = path->slots[0]; write_extent_buffer(leaf, extent_info->extent_buf, btrfs_item_ptr_offset(leaf, slot), sizeof(struct btrfs_file_extent_item)); extent = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); ASSERT(btrfs_file_extent_type(leaf, extent) != BTRFS_FILE_EXTENT_INLINE); btrfs_set_file_extent_offset(leaf, extent, extent_info->data_offset); btrfs_set_file_extent_num_bytes(leaf, extent, replace_len); if (extent_info->is_new_extent) btrfs_set_file_extent_generation(leaf, extent, trans->transid); btrfs_mark_buffer_dirty(trans, leaf); btrfs_release_path(path); ret = btrfs_inode_set_file_extent_range(inode, extent_info->file_offset, replace_len); if (ret) return ret; /* If it's a hole, nothing more needs to be done. */ if (extent_info->disk_offset == 0) { btrfs_update_inode_bytes(inode, 0, bytes_to_drop); return 0; } btrfs_update_inode_bytes(inode, replace_len, bytes_to_drop); if (extent_info->is_new_extent && extent_info->insertions == 0) { key.objectid = extent_info->disk_offset; key.type = BTRFS_EXTENT_ITEM_KEY; key.offset = extent_info->disk_len; ret = btrfs_alloc_reserved_file_extent(trans, root, btrfs_ino(inode), extent_info->file_offset, extent_info->qgroup_reserved, &key); } else { u64 ref_offset; btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF, extent_info->disk_offset, extent_info->disk_len, 0, root->root_key.objectid); ref_offset = extent_info->file_offset - extent_info->data_offset; btrfs_init_data_ref(&ref, root->root_key.objectid, btrfs_ino(inode), ref_offset, 0, false); ret = btrfs_inc_extent_ref(trans, &ref); } extent_info->insertions++; return ret; } /* * The respective range must have been previously locked, as well as the inode. * The end offset is inclusive (last byte of the range). * @extent_info is NULL for fallocate's hole punching and non-NULL when replacing * the file range with an extent. * When not punching a hole, we don't want to end up in a state where we dropped * extents without inserting a new one, so we must abort the transaction to avoid * a corruption. */ int btrfs_replace_file_extents(struct btrfs_inode *inode, struct btrfs_path *path, const u64 start, const u64 end, struct btrfs_replace_extent_info *extent_info, struct btrfs_trans_handle **trans_out) { struct btrfs_drop_extents_args drop_args = { 0 }; struct btrfs_root *root = inode->root; struct btrfs_fs_info *fs_info = root->fs_info; u64 min_size = btrfs_calc_insert_metadata_size(fs_info, 1); u64 ino_size = round_up(inode->vfs_inode.i_size, fs_info->sectorsize); struct btrfs_trans_handle *trans = NULL; struct btrfs_block_rsv *rsv; unsigned int rsv_count; u64 cur_offset; u64 len = end - start; int ret = 0; if (end <= start) return -EINVAL; rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP); if (!rsv) { ret = -ENOMEM; goto out; } rsv->size = btrfs_calc_insert_metadata_size(fs_info, 1); rsv->failfast = true; /* * 1 - update the inode * 1 - removing the extents in the range * 1 - adding the hole extent if no_holes isn't set or if we are * replacing the range with a new extent */ if (!btrfs_fs_incompat(fs_info, NO_HOLES) || extent_info) rsv_count = 3; else rsv_count = 2; trans = btrfs_start_transaction(root, rsv_count); if (IS_ERR(trans)) { ret = PTR_ERR(trans); trans = NULL; goto out_free; } ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv, min_size, false); if (WARN_ON(ret)) goto out_trans; trans->block_rsv = rsv; cur_offset = start; drop_args.path = path; drop_args.end = end + 1; drop_args.drop_cache = true; while (cur_offset < end) { drop_args.start = cur_offset; ret = btrfs_drop_extents(trans, root, inode, &drop_args); /* If we are punching a hole decrement the inode's byte count */ if (!extent_info) btrfs_update_inode_bytes(inode, 0, drop_args.bytes_found); if (ret != -ENOSPC) { /* * The only time we don't want to abort is if we are * attempting to clone a partial inline extent, in which * case we'll get EOPNOTSUPP. However if we aren't * clone we need to abort no matter what, because if we * got EOPNOTSUPP via prealloc then we messed up and * need to abort. */ if (ret && (ret != -EOPNOTSUPP || (extent_info && extent_info->is_new_extent))) btrfs_abort_transaction(trans, ret); break; } trans->block_rsv = &fs_info->trans_block_rsv; if (!extent_info && cur_offset < drop_args.drop_end && cur_offset < ino_size) { ret = fill_holes(trans, inode, path, cur_offset, drop_args.drop_end); if (ret) { /* * If we failed then we didn't insert our hole * entries for the area we dropped, so now the * fs is corrupted, so we must abort the * transaction. */ btrfs_abort_transaction(trans, ret); break; } } else if (!extent_info && cur_offset < drop_args.drop_end) { /* * We are past the i_size here, but since we didn't * insert holes we need to clear the mapped area so we * know to not set disk_i_size in this area until a new * file extent is inserted here. */ ret = btrfs_inode_clear_file_extent_range(inode, cur_offset, drop_args.drop_end - cur_offset); if (ret) { /* * We couldn't clear our area, so we could * presumably adjust up and corrupt the fs, so * we need to abort. */ btrfs_abort_transaction(trans, ret); break; } } if (extent_info && drop_args.drop_end > extent_info->file_offset) { u64 replace_len = drop_args.drop_end - extent_info->file_offset; ret = btrfs_insert_replace_extent(trans, inode, path, extent_info, replace_len, drop_args.bytes_found); if (ret) { btrfs_abort_transaction(trans, ret); break; } extent_info->data_len -= replace_len; extent_info->data_offset += replace_len; extent_info->file_offset += replace_len; } /* * We are releasing our handle on the transaction, balance the * dirty pages of the btree inode and flush delayed items, and * then get a new transaction handle, which may now point to a * new transaction in case someone else may have committed the * transaction we used to replace/drop file extent items. So * bump the inode's iversion and update mtime and ctime except * if we are called from a dedupe context. This is because a * power failure/crash may happen after the transaction is * committed and before we finish replacing/dropping all the * file extent items we need. */ inode_inc_iversion(&inode->vfs_inode); if (!extent_info || extent_info->update_times) inode_set_mtime_to_ts(&inode->vfs_inode, inode_set_ctime_current(&inode->vfs_inode)); ret = btrfs_update_inode(trans, inode); if (ret) break; btrfs_end_transaction(trans); btrfs_btree_balance_dirty(fs_info); trans = btrfs_start_transaction(root, rsv_count); if (IS_ERR(trans)) { ret = PTR_ERR(trans); trans = NULL; break; } ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv, min_size, false); if (WARN_ON(ret)) break; trans->block_rsv = rsv; cur_offset = drop_args.drop_end; len = end - cur_offset; if (!extent_info && len) { ret = find_first_non_hole(inode, &cur_offset, &len); if (unlikely(ret < 0)) break; if (ret && !len) { ret = 0; break; } } } /* * If we were cloning, force the next fsync to be a full one since we * we replaced (or just dropped in the case of cloning holes when * NO_HOLES is enabled) file extent items and did not setup new extent * maps for the replacement extents (or holes). */ if (extent_info && !extent_info->is_new_extent) btrfs_set_inode_full_sync(inode); if (ret) goto out_trans; trans->block_rsv = &fs_info->trans_block_rsv; /* * If we are using the NO_HOLES feature we might have had already an * hole that overlaps a part of the region [lockstart, lockend] and * ends at (or beyond) lockend. Since we have no file extent items to * represent holes, drop_end can be less than lockend and so we must * make sure we have an extent map representing the existing hole (the * call to __btrfs_drop_extents() might have dropped the existing extent * map representing the existing hole), otherwise the fast fsync path * will not record the existence of the hole region * [existing_hole_start, lockend]. */ if (drop_args.drop_end <= end) drop_args.drop_end = end + 1; /* * Don't insert file hole extent item if it's for a range beyond eof * (because it's useless) or if it represents a 0 bytes range (when * cur_offset == drop_end). */ if (!extent_info && cur_offset < ino_size && cur_offset < drop_args.drop_end) { ret = fill_holes(trans, inode, path, cur_offset, drop_args.drop_end); if (ret) { /* Same comment as above. */ btrfs_abort_transaction(trans, ret); goto out_trans; } } else if (!extent_info && cur_offset < drop_args.drop_end) { /* See the comment in the loop above for the reasoning here. */ ret = btrfs_inode_clear_file_extent_range(inode, cur_offset, drop_args.drop_end - cur_offset); if (ret) { btrfs_abort_transaction(trans, ret); goto out_trans; } } if (extent_info) { ret = btrfs_insert_replace_extent(trans, inode, path, extent_info, extent_info->data_len, drop_args.bytes_found); if (ret) { btrfs_abort_transaction(trans, ret); goto out_trans; } } out_trans: if (!trans) goto out_free; trans->block_rsv = &fs_info->trans_block_rsv; if (ret) btrfs_end_transaction(trans); else *trans_out = trans; out_free: btrfs_free_block_rsv(fs_info, rsv); out: return ret; } static int btrfs_punch_hole(struct file *file, loff_t offset, loff_t len) { struct inode *inode = file_inode(file); struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); struct btrfs_root *root = BTRFS_I(inode)->root; struct extent_state *cached_state = NULL; struct btrfs_path *path; struct btrfs_trans_handle *trans = NULL; u64 lockstart; u64 lockend; u64 tail_start; u64 tail_len; u64 orig_start = offset; int ret = 0; bool same_block; u64 ino_size; bool truncated_block = false; bool updated_inode = false; btrfs_inode_lock(BTRFS_I(inode), BTRFS_ILOCK_MMAP); ret = btrfs_wait_ordered_range(inode, offset, len); if (ret) goto out_only_mutex; ino_size = round_up(inode->i_size, fs_info->sectorsize); ret = find_first_non_hole(BTRFS_I(inode), &offset, &len); if (ret < 0) goto out_only_mutex; if (ret && !len) { /* Already in a large hole */ ret = 0; goto out_only_mutex; } ret = file_modified(file); if (ret) goto out_only_mutex; lockstart = round_up(offset, fs_info->sectorsize); lockend = round_down(offset + len, fs_info->sectorsize) - 1; same_block = (BTRFS_BYTES_TO_BLKS(fs_info, offset)) == (BTRFS_BYTES_TO_BLKS(fs_info, offset + len - 1)); /* * We needn't truncate any block which is beyond the end of the file * because we are sure there is no data there. */ /* * Only do this if we are in the same block and we aren't doing the * entire block. */ if (same_block && len < fs_info->sectorsize) { if (offset < ino_size) { truncated_block = true; ret = btrfs_truncate_block(BTRFS_I(inode), offset, len, 0); } else { ret = 0; } goto out_only_mutex; } /* zero back part of the first block */ if (offset < ino_size) { truncated_block = true; ret = btrfs_truncate_block(BTRFS_I(inode), offset, 0, 0); if (ret) { btrfs_inode_unlock(BTRFS_I(inode), BTRFS_ILOCK_MMAP); return ret; } } /* Check the aligned pages after the first unaligned page, * if offset != orig_start, which means the first unaligned page * including several following pages are already in holes, * the extra check can be skipped */ if (offset == orig_start) { /* after truncate page, check hole again */ len = offset + len - lockstart; offset = lockstart; ret = find_first_non_hole(BTRFS_I(inode), &offset, &len); if (ret < 0) goto out_only_mutex; if (ret && !len) { ret = 0; goto out_only_mutex; } lockstart = offset; } /* Check the tail unaligned part is in a hole */ tail_start = lockend + 1; tail_len = offset + len - tail_start; if (tail_len) { ret = find_first_non_hole(BTRFS_I(inode), &tail_start, &tail_len); if (unlikely(ret < 0)) goto out_only_mutex; if (!ret) { /* zero the front end of the last page */ if (tail_start + tail_len < ino_size) { truncated_block = true; ret = btrfs_truncate_block(BTRFS_I(inode), tail_start + tail_len, 0, 1); if (ret) goto out_only_mutex; } } } if (lockend < lockstart) { ret = 0; goto out_only_mutex; } btrfs_punch_hole_lock_range(inode, lockstart, lockend, &cached_state); path = btrfs_alloc_path(); if (!path) { ret = -ENOMEM; goto out; } ret = btrfs_replace_file_extents(BTRFS_I(inode), path, lockstart, lockend, NULL, &trans); btrfs_free_path(path); if (ret) goto out; ASSERT(trans != NULL); inode_inc_iversion(inode); inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode)); ret = btrfs_update_inode(trans, BTRFS_I(inode)); updated_inode = true; btrfs_end_transaction(trans); btrfs_btree_balance_dirty(fs_info); out: unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend, &cached_state); out_only_mutex: if (!updated_inode && truncated_block && !ret) { /* * If we only end up zeroing part of a page, we still need to * update the inode item, so that all the time fields are * updated as well as the necessary btrfs inode in memory fields * for detecting, at fsync time, if the inode isn't yet in the * log tree or it's there but not up to date. */ struct timespec64 now = inode_set_ctime_current(inode); inode_inc_iversion(inode); inode_set_mtime_to_ts(inode, now); trans = btrfs_start_transaction(root, 1); if (IS_ERR(trans)) { ret = PTR_ERR(trans); } else { int ret2; ret = btrfs_update_inode(trans, BTRFS_I(inode)); ret2 = btrfs_end_transaction(trans); if (!ret) ret = ret2; } } btrfs_inode_unlock(BTRFS_I(inode), BTRFS_ILOCK_MMAP); return ret; } /* Helper structure to record which range is already reserved */ struct falloc_range { struct list_head list; u64 start; u64 len; }; /* * Helper function to add falloc range * * Caller should have locked the larger range of extent containing * [start, len) */ static int add_falloc_range(struct list_head *head, u64 start, u64 len) { struct falloc_range *range = NULL; if (!list_empty(head)) { /* * As fallocate iterates by bytenr order, we only need to check * the last range. */ range = list_last_entry(head, struct falloc_range, list); if (range->start + range->len == start) { range->len += len; return 0; } } range = kmalloc(sizeof(*range), GFP_KERNEL); if (!range) return -ENOMEM; range->start = start; range->len = len; list_add_tail(&range->list, head); return 0; } static int btrfs_fallocate_update_isize(struct inode *inode, const u64 end, const int mode) { struct btrfs_trans_handle *trans; struct btrfs_root *root = BTRFS_I(inode)->root; int ret; int ret2; if (mode & FALLOC_FL_KEEP_SIZE || end <= i_size_read(inode)) return 0; trans = btrfs_start_transaction(root, 1); if (IS_ERR(trans)) return PTR_ERR(trans); inode_set_ctime_current(inode); i_size_write(inode, end); btrfs_inode_safe_disk_i_size_write(BTRFS_I(inode), 0); ret = btrfs_update_inode(trans, BTRFS_I(inode)); ret2 = btrfs_end_transaction(trans); return ret ? ret : ret2; } enum { RANGE_BOUNDARY_WRITTEN_EXTENT, RANGE_BOUNDARY_PREALLOC_EXTENT, RANGE_BOUNDARY_HOLE, }; static int btrfs_zero_range_check_range_boundary(struct btrfs_inode *inode, u64 offset) { const u64 sectorsize = inode->root->fs_info->sectorsize; struct extent_map *em; int ret; offset = round_down(offset, sectorsize); em = btrfs_get_extent(inode, NULL, 0, offset, sectorsize); if (IS_ERR(em)) return PTR_ERR(em); if (em->block_start == EXTENT_MAP_HOLE) ret = RANGE_BOUNDARY_HOLE; else if (em->flags & EXTENT_FLAG_PREALLOC) ret = RANGE_BOUNDARY_PREALLOC_EXTENT; else ret = RANGE_BOUNDARY_WRITTEN_EXTENT; free_extent_map(em); return ret; } static int btrfs_zero_range(struct inode *inode, loff_t offset, loff_t len, const int mode) { struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info; struct extent_map *em; struct extent_changeset *data_reserved = NULL; int ret; u64 alloc_hint = 0; const u64 sectorsize = fs_info->sectorsize; u64 alloc_start = round_down(offset, sectorsize); u64 alloc_end = round_up(offset + len, sectorsize); u64 bytes_to_reserve = 0; bool space_reserved = false; em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, alloc_start, alloc_end - alloc_start); if (IS_ERR(em)) { ret = PTR_ERR(em); goto out; } /* * Avoid hole punching and extent allocation for some cases. More cases * could be considered, but these are unlikely common and we keep things * as simple as possible for now. Also, intentionally, if the target * range contains one or more prealloc extents together with regular * extents and holes, we drop all the existing extents and allocate a * new prealloc extent, so that we get a larger contiguous disk extent. */ if (em->start <= alloc_start && (em->flags & EXTENT_FLAG_PREALLOC)) { const u64 em_end = em->start + em->len; if (em_end >= offset + len) { /* * The whole range is already a prealloc extent, * do nothing except updating the inode's i_size if * needed. */ free_extent_map(em); ret = btrfs_fallocate_update_isize(inode, offset + len, mode); goto out; } /* * Part of the range is already a prealloc extent, so operate * only on the remaining part of the range. */ alloc_start = em_end; ASSERT(IS_ALIGNED(alloc_start, sectorsize)); len = offset + len - alloc_start; offset = alloc_start; alloc_hint = em->block_start + em->len; } free_extent_map(em); if (BTRFS_BYTES_TO_BLKS(fs_info, offset) == BTRFS_BYTES_TO_BLKS(fs_info, offset + len - 1)) { em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, alloc_start, sectorsize); if (IS_ERR(em)) { ret = PTR_ERR(em); goto out; } if (em->flags & EXTENT_FLAG_PREALLOC) { free_extent_map(em); ret = btrfs_fallocate_update_isize(inode, offset + len, mode); goto out; } if (len < sectorsize && em->block_start != EXTENT_MAP_HOLE) { free_extent_map(em); ret = btrfs_truncate_block(BTRFS_I(inode), offset, len, 0); if (!ret) ret = btrfs_fallocate_update_isize(inode, offset + len, mode); return ret; } free_extent_map(em); alloc_start = round_down(offset, sectorsize); alloc_end = alloc_start + sectorsize; goto reserve_space; } alloc_start = round_up(offset, sectorsize); alloc_end = round_down(offset + len, sectorsize); /* * For unaligned ranges, check the pages at the boundaries, they might * map to an extent, in which case we need to partially zero them, or * they might map to a hole, in which case we need our allocation range * to cover them. */ if (!IS_ALIGNED(offset, sectorsize)) { ret = btrfs_zero_range_check_range_boundary(BTRFS_I(inode), offset); if (ret < 0) goto out; if (ret == RANGE_BOUNDARY_HOLE) { alloc_start = round_down(offset, sectorsize); ret = 0; } else if (ret == RANGE_BOUNDARY_WRITTEN_EXTENT) { ret = btrfs_truncate_block(BTRFS_I(inode), offset, 0, 0); if (ret) goto out; } else { ret = 0; } } if (!IS_ALIGNED(offset + len, sectorsize)) { ret = btrfs_zero_range_check_range_boundary(BTRFS_I(inode), offset + len); if (ret < 0) goto out; if (ret == RANGE_BOUNDARY_HOLE) { alloc_end = round_up(offset + len, sectorsize); ret = 0; } else if (ret == RANGE_BOUNDARY_WRITTEN_EXTENT) { ret = btrfs_truncate_block(BTRFS_I(inode), offset + len, 0, 1); if (ret) goto out; } else { ret = 0; } } reserve_space: if (alloc_start < alloc_end) { struct extent_state *cached_state = NULL; const u64 lockstart = alloc_start; const u64 lockend = alloc_end - 1; bytes_to_reserve = alloc_end - alloc_start; ret = btrfs_alloc_data_chunk_ondemand(BTRFS_I(inode), bytes_to_reserve); if (ret < 0) goto out; space_reserved = true; btrfs_punch_hole_lock_range(inode, lockstart, lockend, &cached_state); ret = btrfs_qgroup_reserve_data(BTRFS_I(inode), &data_reserved, alloc_start, bytes_to_reserve); if (ret) { unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend, &cached_state); goto out; } ret = btrfs_prealloc_file_range(inode, mode, alloc_start, alloc_end - alloc_start, i_blocksize(inode), offset + len, &alloc_hint); unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend, &cached_state); /* btrfs_prealloc_file_range releases reserved space on error */ if (ret) { space_reserved = false; goto out; } } ret = btrfs_fallocate_update_isize(inode, offset + len, mode); out: if (ret && space_reserved) btrfs_free_reserved_data_space(BTRFS_I(inode), data_reserved, alloc_start, bytes_to_reserve); extent_changeset_free(data_reserved); return ret; } static long btrfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len) { struct inode *inode = file_inode(file); struct extent_state *cached_state = NULL; struct extent_changeset *data_reserved = NULL; struct falloc_range *range; struct falloc_range *tmp; LIST_HEAD(reserve_list); u64 cur_offset; u64 last_byte; u64 alloc_start; u64 alloc_end; u64 alloc_hint = 0; u64 locked_end; u64 actual_end = 0; u64 data_space_needed = 0; u64 data_space_reserved = 0; u64 qgroup_reserved = 0; struct extent_map *em; int blocksize = BTRFS_I(inode)->root->fs_info->sectorsize; int ret; /* Do not allow fallocate in ZONED mode */ if (btrfs_is_zoned(btrfs_sb(inode->i_sb))) return -EOPNOTSUPP; alloc_start = round_down(offset, blocksize); alloc_end = round_up(offset + len, blocksize); cur_offset = alloc_start; /* Make sure we aren't being give some crap mode */ if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE)) return -EOPNOTSUPP; if (mode & FALLOC_FL_PUNCH_HOLE) return btrfs_punch_hole(file, offset, len); btrfs_inode_lock(BTRFS_I(inode), BTRFS_ILOCK_MMAP); if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size) { ret = inode_newsize_ok(inode, offset + len); if (ret) goto out; } ret = file_modified(file); if (ret) goto out; /* * TODO: Move these two operations after we have checked * accurate reserved space, or fallocate can still fail but * with page truncated or size expanded. * * But that's a minor problem and won't do much harm BTW. */ if (alloc_start > inode->i_size) { ret = btrfs_cont_expand(BTRFS_I(inode), i_size_read(inode), alloc_start); if (ret) goto out; } else if (offset + len > inode->i_size) { /* * If we are fallocating from the end of the file onward we * need to zero out the end of the block if i_size lands in the * middle of a block. */ ret = btrfs_truncate_block(BTRFS_I(inode), inode->i_size, 0, 0); if (ret) goto out; } /* * We have locked the inode at the VFS level (in exclusive mode) and we * have locked the i_mmap_lock lock (in exclusive mode). Now before * locking the file range, flush all dealloc in the range and wait for * all ordered extents in the range to complete. After this we can lock * the file range and, due to the previous locking we did, we know there * can't be more delalloc or ordered extents in the range. */ ret = btrfs_wait_ordered_range(inode, alloc_start, alloc_end - alloc_start); if (ret) goto out; if (mode & FALLOC_FL_ZERO_RANGE) { ret = btrfs_zero_range(inode, offset, len, mode); btrfs_inode_unlock(BTRFS_I(inode), BTRFS_ILOCK_MMAP); return ret; } locked_end = alloc_end - 1; lock_extent(&BTRFS_I(inode)->io_tree, alloc_start, locked_end, &cached_state); btrfs_assert_inode_range_clean(BTRFS_I(inode), alloc_start, locked_end); /* First, check if we exceed the qgroup limit */ while (cur_offset < alloc_end) { em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, cur_offset, alloc_end - cur_offset); if (IS_ERR(em)) { ret = PTR_ERR(em); break; } last_byte = min(extent_map_end(em), alloc_end); actual_end = min_t(u64, extent_map_end(em), offset + len); last_byte = ALIGN(last_byte, blocksize); if (em->block_start == EXTENT_MAP_HOLE || (cur_offset >= inode->i_size && !(em->flags & EXTENT_FLAG_PREALLOC))) { const u64 range_len = last_byte - cur_offset; ret = add_falloc_range(&reserve_list, cur_offset, range_len); if (ret < 0) { free_extent_map(em); break; } ret = btrfs_qgroup_reserve_data(BTRFS_I(inode), &data_reserved, cur_offset, range_len); if (ret < 0) { free_extent_map(em); break; } qgroup_reserved += range_len; data_space_needed += range_len; } free_extent_map(em); cur_offset = last_byte; } if (!ret && data_space_needed > 0) { /* * We are safe to reserve space here as we can't have delalloc * in the range, see above. */ ret = btrfs_alloc_data_chunk_ondemand(BTRFS_I(inode), data_space_needed); if (!ret) data_space_reserved = data_space_needed; } /* * If ret is still 0, means we're OK to fallocate. * Or just cleanup the list and exit. */ list_for_each_entry_safe(range, tmp, &reserve_list, list) { if (!ret) { ret = btrfs_prealloc_file_range(inode, mode, range->start, range->len, i_blocksize(inode), offset + len, &alloc_hint); /* * btrfs_prealloc_file_range() releases space even * if it returns an error. */ data_space_reserved -= range->len; qgroup_reserved -= range->len; } else if (data_space_reserved > 0) { btrfs_free_reserved_data_space(BTRFS_I(inode), data_reserved, range->start, range->len); data_space_reserved -= range->len; qgroup_reserved -= range->len; } else if (qgroup_reserved > 0) { btrfs_qgroup_free_data(BTRFS_I(inode), data_reserved, range->start, range->len, NULL); qgroup_reserved -= range->len; } list_del(&range->list); kfree(range); } if (ret < 0) goto out_unlock; /* * We didn't need to allocate any more space, but we still extended the * size of the file so we need to update i_size and the inode item. */ ret = btrfs_fallocate_update_isize(inode, actual_end, mode); out_unlock: unlock_extent(&BTRFS_I(inode)->io_tree, alloc_start, locked_end, &cached_state); out: btrfs_inode_unlock(BTRFS_I(inode), BTRFS_ILOCK_MMAP); extent_changeset_free(data_reserved); return ret; } /* * Helper for btrfs_find_delalloc_in_range(). Find a subrange in a given range * that has unflushed and/or flushing delalloc. There might be other adjacent * subranges after the one it found, so btrfs_find_delalloc_in_range() keeps * looping while it gets adjacent subranges, and merging them together. */ static bool find_delalloc_subrange(struct btrfs_inode *inode, u64 start, u64 end, struct extent_state **cached_state, bool *search_io_tree, u64 *delalloc_start_ret, u64 *delalloc_end_ret) { u64 len = end + 1 - start; u64 delalloc_len = 0; struct btrfs_ordered_extent *oe; u64 oe_start; u64 oe_end; /* * Search the io tree first for EXTENT_DELALLOC. If we find any, it * means we have delalloc (dirty pages) for which writeback has not * started yet. */ if (*search_io_tree) { spin_lock(&inode->lock); if (inode->delalloc_bytes > 0) { spin_unlock(&inode->lock); *delalloc_start_ret = start; delalloc_len = count_range_bits(&inode->io_tree, delalloc_start_ret, end, len, EXTENT_DELALLOC, 1, cached_state); } else { spin_unlock(&inode->lock); } } if (delalloc_len > 0) { /* * If delalloc was found then *delalloc_start_ret has a sector size * aligned value (rounded down). */ *delalloc_end_ret = *delalloc_start_ret + delalloc_len - 1; if (*delalloc_start_ret == start) { /* Delalloc for the whole range, nothing more to do. */ if (*delalloc_end_ret == end) return true; /* Else trim our search range for ordered extents. */ start = *delalloc_end_ret + 1; len = end + 1 - start; } } else { /* No delalloc, future calls don't need to search again. */ *search_io_tree = false; } /* * Now also check if there's any ordered extent in the range. * We do this because: * * 1) When delalloc is flushed, the file range is locked, we clear the * EXTENT_DELALLOC bit from the io tree and create an extent map and * an ordered extent for the write. So we might just have been called * after delalloc is flushed and before the ordered extent completes * and inserts the new file extent item in the subvolume's btree; * * 2) We may have an ordered extent created by flushing delalloc for a * subrange that starts before the subrange we found marked with * EXTENT_DELALLOC in the io tree. * * We could also use the extent map tree to find such delalloc that is * being flushed, but using the ordered extents tree is more efficient * because it's usually much smaller as ordered extents are removed from * the tree once they complete. With the extent maps, we mau have them * in the extent map tree for a very long time, and they were either * created by previous writes or loaded by read operations. */ oe = btrfs_lookup_first_ordered_range(inode, start, len); if (!oe) return (delalloc_len > 0); /* The ordered extent may span beyond our search range. */ oe_start = max(oe->file_offset, start); oe_end = min(oe->file_offset + oe->num_bytes - 1, end); btrfs_put_ordered_extent(oe); /* Don't have unflushed delalloc, return the ordered extent range. */ if (delalloc_len == 0) { *delalloc_start_ret = oe_start; *delalloc_end_ret = oe_end; return true; } /* * We have both unflushed delalloc (io_tree) and an ordered extent. * If the ranges are adjacent returned a combined range, otherwise * return the leftmost range. */ if (oe_start < *delalloc_start_ret) { if (oe_end < *delalloc_start_ret) *delalloc_end_ret = oe_end; *delalloc_start_ret = oe_start; } else if (*delalloc_end_ret + 1 == oe_start) { *delalloc_end_ret = oe_end; } return true; } /* * Check if there's delalloc in a given range. * * @inode: The inode. * @start: The start offset of the range. It does not need to be * sector size aligned. * @end: The end offset (inclusive value) of the search range. * It does not need to be sector size aligned. * @cached_state: Extent state record used for speeding up delalloc * searches in the inode's io_tree. Can be NULL. * @delalloc_start_ret: Output argument, set to the start offset of the * subrange found with delalloc (may not be sector size * aligned). * @delalloc_end_ret: Output argument, set to he end offset (inclusive value) * of the subrange found with delalloc. * * Returns true if a subrange with delalloc is found within the given range, and * if so it sets @delalloc_start_ret and @delalloc_end_ret with the start and * end offsets of the subrange. */ bool btrfs_find_delalloc_in_range(struct btrfs_inode *inode, u64 start, u64 end, struct extent_state **cached_state, u64 *delalloc_start_ret, u64 *delalloc_end_ret) { u64 cur_offset = round_down(start, inode->root->fs_info->sectorsize); u64 prev_delalloc_end = 0; bool search_io_tree = true; bool ret = false; while (cur_offset <= end) { u64 delalloc_start; u64 delalloc_end; bool delalloc; delalloc = find_delalloc_subrange(inode, cur_offset, end, cached_state, &search_io_tree, &delalloc_start, &delalloc_end); if (!delalloc) break; if (prev_delalloc_end == 0) { /* First subrange found. */ *delalloc_start_ret = max(delalloc_start, start); *delalloc_end_ret = delalloc_end; ret = true; } else if (delalloc_start == prev_delalloc_end + 1) { /* Subrange adjacent to the previous one, merge them. */ *delalloc_end_ret = delalloc_end; } else { /* Subrange not adjacent to the previous one, exit. */ break; } prev_delalloc_end = delalloc_end; cur_offset = delalloc_end + 1; cond_resched(); } return ret; } /* * Check if there's a hole or delalloc range in a range representing a hole (or * prealloc extent) found in the inode's subvolume btree. * * @inode: The inode. * @whence: Seek mode (SEEK_DATA or SEEK_HOLE). * @start: Start offset of the hole region. It does not need to be sector * size aligned. * @end: End offset (inclusive value) of the hole region. It does not * need to be sector size aligned. * @start_ret: Return parameter, used to set the start of the subrange in the * hole that matches the search criteria (seek mode), if such * subrange is found (return value of the function is true). * The value returned here may not be sector size aligned. * * Returns true if a subrange matching the given seek mode is found, and if one * is found, it updates @start_ret with the start of the subrange. */ static bool find_desired_extent_in_hole(struct btrfs_inode *inode, int whence, struct extent_state **cached_state, u64 start, u64 end, u64 *start_ret) { u64 delalloc_start; u64 delalloc_end; bool delalloc; delalloc = btrfs_find_delalloc_in_range(inode, start, end, cached_state, &delalloc_start, &delalloc_end); if (delalloc && whence == SEEK_DATA) { *start_ret = delalloc_start; return true; } if (delalloc && whence == SEEK_HOLE) { /* * We found delalloc but it starts after out start offset. So we * have a hole between our start offset and the delalloc start. */ if (start < delalloc_start) { *start_ret = start; return true; } /* * Delalloc range starts at our start offset. * If the delalloc range's length is smaller than our range, * then it means we have a hole that starts where the delalloc * subrange ends. */ if (delalloc_end < end) { *start_ret = delalloc_end + 1; return true; } /* There's delalloc for the whole range. */ return false; } if (!delalloc && whence == SEEK_HOLE) { *start_ret = start; return true; } /* * No delalloc in the range and we are seeking for data. The caller has * to iterate to the next extent item in the subvolume btree. */ return false; } static loff_t find_desired_extent(struct file *file, loff_t offset, int whence) { struct btrfs_inode *inode = BTRFS_I(file->f_mapping->host); struct btrfs_file_private *private = file->private_data; struct btrfs_fs_info *fs_info = inode->root->fs_info; struct extent_state *cached_state = NULL; struct extent_state **delalloc_cached_state; const loff_t i_size = i_size_read(&inode->vfs_inode); const u64 ino = btrfs_ino(inode); struct btrfs_root *root = inode->root; struct btrfs_path *path; struct btrfs_key key; u64 last_extent_end; u64 lockstart; u64 lockend; u64 start; int ret; bool found = false; if (i_size == 0 || offset >= i_size) return -ENXIO; /* * Quick path. If the inode has no prealloc extents and its number of * bytes used matches its i_size, then it can not have holes. */ if (whence == SEEK_HOLE && !(inode->flags & BTRFS_INODE_PREALLOC) && inode_get_bytes(&inode->vfs_inode) == i_size) return i_size; if (!private) { private = kzalloc(sizeof(*private), GFP_KERNEL); /* * No worries if memory allocation failed. * The private structure is used only for speeding up multiple * lseek SEEK_HOLE/DATA calls to a file when there's delalloc, * so everything will still be correct. */ file->private_data = private; } if (private) delalloc_cached_state = &private->llseek_cached_state; else delalloc_cached_state = NULL; /* * offset can be negative, in this case we start finding DATA/HOLE from * the very start of the file. */ start = max_t(loff_t, 0, offset); lockstart = round_down(start, fs_info->sectorsize); lockend = round_up(i_size, fs_info->sectorsize); if (lockend <= lockstart) lockend = lockstart + fs_info->sectorsize; lockend--; path = btrfs_alloc_path(); if (!path) return -ENOMEM; path->reada = READA_FORWARD; key.objectid = ino; key.type = BTRFS_EXTENT_DATA_KEY; key.offset = start; last_extent_end = lockstart; lock_extent(&inode->io_tree, lockstart, lockend, &cached_state); ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) { goto out; } else if (ret > 0 && path->slots[0] > 0) { btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0] - 1); if (key.objectid == ino && key.type == BTRFS_EXTENT_DATA_KEY) path->slots[0]--; } while (start < i_size) { struct extent_buffer *leaf = path->nodes[0]; struct btrfs_file_extent_item *extent; u64 extent_end; u8 type; if (path->slots[0] >= btrfs_header_nritems(leaf)) { ret = btrfs_next_leaf(root, path); if (ret < 0) goto out; else if (ret > 0) break; leaf = path->nodes[0]; } btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); if (key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY) break; extent_end = btrfs_file_extent_end(path); /* * In the first iteration we may have a slot that points to an * extent that ends before our start offset, so skip it. */ if (extent_end <= start) { path->slots[0]++; continue; } /* We have an implicit hole, NO_HOLES feature is likely set. */ if (last_extent_end < key.offset) { u64 search_start = last_extent_end; u64 found_start; /* * First iteration, @start matches @offset and it's * within the hole. */ if (start == offset) search_start = offset; found = find_desired_extent_in_hole(inode, whence, delalloc_cached_state, search_start, key.offset - 1, &found_start); if (found) { start = found_start; break; } /* * Didn't find data or a hole (due to delalloc) in the * implicit hole range, so need to analyze the extent. */ } extent = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); type = btrfs_file_extent_type(leaf, extent); /* * Can't access the extent's disk_bytenr field if this is an * inline extent, since at that offset, it's where the extent * data starts. */ if (type == BTRFS_FILE_EXTENT_PREALLOC || (type == BTRFS_FILE_EXTENT_REG && btrfs_file_extent_disk_bytenr(leaf, extent) == 0)) { /* * Explicit hole or prealloc extent, search for delalloc. * A prealloc extent is treated like a hole. */ u64 search_start = key.offset; u64 found_start; /* * First iteration, @start matches @offset and it's * within the hole. */ if (start == offset) search_start = offset; found = find_desired_extent_in_hole(inode, whence, delalloc_cached_state, search_start, extent_end - 1, &found_start); if (found) { start = found_start; break; } /* * Didn't find data or a hole (due to delalloc) in the * implicit hole range, so need to analyze the next * extent item. */ } else { /* * Found a regular or inline extent. * If we are seeking for data, adjust the start offset * and stop, we're done. */ if (whence == SEEK_DATA) { start = max_t(u64, key.offset, offset); found = true; break; } /* * Else, we are seeking for a hole, check the next file * extent item. */ } start = extent_end; last_extent_end = extent_end; path->slots[0]++; if (fatal_signal_pending(current)) { ret = -EINTR; goto out; } cond_resched(); } /* We have an implicit hole from the last extent found up to i_size. */ if (!found && start < i_size) { found = find_desired_extent_in_hole(inode, whence, delalloc_cached_state, start, i_size - 1, &start); if (!found) start = i_size; } out: unlock_extent(&inode->io_tree, lockstart, lockend, &cached_state); btrfs_free_path(path); if (ret < 0) return ret; if (whence == SEEK_DATA && start >= i_size) return -ENXIO; return min_t(loff_t, start, i_size); } static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence) { struct inode *inode = file->f_mapping->host; switch (whence) { default: return generic_file_llseek(file, offset, whence); case SEEK_DATA: case SEEK_HOLE: btrfs_inode_lock(BTRFS_I(inode), BTRFS_ILOCK_SHARED); offset = find_desired_extent(file, offset, whence); btrfs_inode_unlock(BTRFS_I(inode), BTRFS_ILOCK_SHARED); break; } if (offset < 0) return offset; return vfs_setpos(file, offset, inode->i_sb->s_maxbytes); } static int btrfs_file_open(struct inode *inode, struct file *filp) { int ret; filp->f_mode |= FMODE_NOWAIT | FMODE_BUF_RASYNC | FMODE_BUF_WASYNC | FMODE_CAN_ODIRECT; ret = fsverity_file_open(inode, filp); if (ret) return ret; return generic_file_open(inode, filp); } static int check_direct_read(struct btrfs_fs_info *fs_info, const struct iov_iter *iter, loff_t offset) { int ret; int i, seg; ret = check_direct_IO(fs_info, iter, offset); if (ret < 0) return ret; if (!iter_is_iovec(iter)) return 0; for (seg = 0; seg < iter->nr_segs; seg++) { for (i = seg + 1; i < iter->nr_segs; i++) { const struct iovec *iov1 = iter_iov(iter) + seg; const struct iovec *iov2 = iter_iov(iter) + i; if (iov1->iov_base == iov2->iov_base) return -EINVAL; } } return 0; } static ssize_t btrfs_direct_read(struct kiocb *iocb, struct iov_iter *to) { struct inode *inode = file_inode(iocb->ki_filp); size_t prev_left = 0; ssize_t read = 0; ssize_t ret; if (fsverity_active(inode)) return 0; if (check_direct_read(btrfs_sb(inode->i_sb), to, iocb->ki_pos)) return 0; btrfs_inode_lock(BTRFS_I(inode), BTRFS_ILOCK_SHARED); again: /* * This is similar to what we do for direct IO writes, see the comment * at btrfs_direct_write(), but we also disable page faults in addition * to disabling them only at the iov_iter level. This is because when * reading from a hole or prealloc extent, iomap calls iov_iter_zero(), * which can still trigger page fault ins despite having set ->nofault * to true of our 'to' iov_iter. * * The difference to direct IO writes is that we deadlock when trying * to lock the extent range in the inode's tree during he page reads * triggered by the fault in (while for writes it is due to waiting for * our own ordered extent). This is because for direct IO reads, * btrfs_dio_iomap_begin() returns with the extent range locked, which * is only unlocked in the endio callback (end_bio_extent_readpage()). */ pagefault_disable(); to->nofault = true; ret = btrfs_dio_read(iocb, to, read); to->nofault = false; pagefault_enable(); /* No increment (+=) because iomap returns a cumulative value. */ if (ret > 0) read = ret; if (iov_iter_count(to) > 0 && (ret == -EFAULT || ret > 0)) { const size_t left = iov_iter_count(to); if (left == prev_left) { /* * We didn't make any progress since the last attempt, * fallback to a buffered read for the remainder of the * range. This is just to avoid any possibility of looping * for too long. */ ret = read; } else { /* * We made some progress since the last retry or this is * the first time we are retrying. Fault in as many pages * as possible and retry. */ fault_in_iov_iter_writeable(to, left); prev_left = left; goto again; } } btrfs_inode_unlock(BTRFS_I(inode), BTRFS_ILOCK_SHARED); return ret < 0 ? ret : read; } static ssize_t btrfs_file_read_iter(struct kiocb *iocb, struct iov_iter *to) { ssize_t ret = 0; if (iocb->ki_flags & IOCB_DIRECT) { ret = btrfs_direct_read(iocb, to); if (ret < 0 || !iov_iter_count(to) || iocb->ki_pos >= i_size_read(file_inode(iocb->ki_filp))) return ret; } return filemap_read(iocb, to, ret); } const struct file_operations btrfs_file_operations = { .llseek = btrfs_file_llseek, .read_iter = btrfs_file_read_iter, .splice_read = filemap_splice_read, .write_iter = btrfs_file_write_iter, .splice_write = iter_file_splice_write, .mmap = btrfs_file_mmap, .open = btrfs_file_open, .release = btrfs_release_file, .get_unmapped_area = thp_get_unmapped_area, .fsync = btrfs_sync_file, .fallocate = btrfs_fallocate, .unlocked_ioctl = btrfs_ioctl, #ifdef CONFIG_COMPAT .compat_ioctl = btrfs_compat_ioctl, #endif .remap_file_range = btrfs_remap_file_range, }; int btrfs_fdatawrite_range(struct inode *inode, loff_t start, loff_t end) { int ret; /* * So with compression we will find and lock a dirty page and clear the * first one as dirty, setup an async extent, and immediately return * with the entire range locked but with nobody actually marked with * writeback. So we can't just filemap_write_and_wait_range() and * expect it to work since it will just kick off a thread to do the * actual work. So we need to call filemap_fdatawrite_range _again_ * since it will wait on the page lock, which won't be unlocked until * after the pages have been marked as writeback and so we're good to go * from there. We have to do this otherwise we'll miss the ordered * extents and that results in badness. Please Josef, do not think you * know better and pull this out at some point in the future, it is * right and you are wrong. */ ret = filemap_fdatawrite_range(inode->i_mapping, start, end); if (!ret && test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, &BTRFS_I(inode)->runtime_flags)) ret = filemap_fdatawrite_range(inode->i_mapping, start, end); return ret; }
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