Author | Tokens | Token Proportion | Commits | Commit Proportion |
---|---|---|---|---|
Filipe David Borba Manana | 3501 | 88.25% | 26 | 25.74% |
Josef Whiter | 138 | 3.48% | 11 | 10.89% |
Qu Wenruo | 59 | 1.49% | 5 | 4.95% |
Mark Fasheh | 47 | 1.18% | 5 | 4.95% |
Christoph Hellwig | 36 | 0.91% | 6 | 5.94% |
Chris Mason | 35 | 0.88% | 11 | 10.89% |
Nikolay Borisov | 35 | 0.88% | 5 | 4.95% |
David Sterba | 22 | 0.55% | 8 | 7.92% |
Jan Kara | 18 | 0.45% | 1 | 0.99% |
Jeff Mahoney | 17 | 0.43% | 3 | 2.97% |
Josef Bacik | 11 | 0.28% | 3 | 2.97% |
Darrick J. Wong | 10 | 0.25% | 1 | 0.99% |
Jeff Layton | 8 | 0.20% | 3 | 2.97% |
Li Zefan | 6 | 0.15% | 1 | 0.99% |
Al Viro | 4 | 0.10% | 1 | 0.99% |
Ira Weiny | 4 | 0.10% | 2 | 1.98% |
Johannes Thumshirn | 3 | 0.08% | 1 | 0.99% |
Zheng Yan | 2 | 0.05% | 1 | 0.99% |
Liu Bo | 2 | 0.05% | 1 | 0.99% |
Matthew Wilcox | 2 | 0.05% | 1 | 0.99% |
Sidong Yang | 2 | 0.05% | 1 | 0.99% |
Zach Brown | 2 | 0.05% | 1 | 0.99% |
David Chinner | 1 | 0.03% | 1 | 0.99% |
Byongho Lee | 1 | 0.03% | 1 | 0.99% |
Filipe Brandenburger | 1 | 0.03% | 1 | 0.99% |
Total | 3967 | 101 |
// SPDX-License-Identifier: GPL-2.0 #include <linux/blkdev.h> #include <linux/iversion.h> #include "ctree.h" #include "fs.h" #include "messages.h" #include "compression.h" #include "delalloc-space.h" #include "disk-io.h" #include "reflink.h" #include "transaction.h" #include "subpage.h" #include "accessors.h" #include "file-item.h" #include "file.h" #include "super.h" #define BTRFS_MAX_DEDUPE_LEN SZ_16M static int clone_finish_inode_update(struct btrfs_trans_handle *trans, struct inode *inode, u64 endoff, const u64 destoff, const u64 olen, int no_time_update) { int ret; inode_inc_iversion(inode); if (!no_time_update) { inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode)); } /* * We round up to the block size at eof when determining which * extents to clone above, but shouldn't round up the file size. */ if (endoff > destoff + olen) endoff = destoff + olen; if (endoff > inode->i_size) { i_size_write(inode, endoff); btrfs_inode_safe_disk_i_size_write(BTRFS_I(inode), 0); } ret = btrfs_update_inode(trans, BTRFS_I(inode)); if (ret) { btrfs_abort_transaction(trans, ret); btrfs_end_transaction(trans); goto out; } ret = btrfs_end_transaction(trans); out: return ret; } static int copy_inline_to_page(struct btrfs_inode *inode, const u64 file_offset, char *inline_data, const u64 size, const u64 datal, const u8 comp_type) { struct btrfs_fs_info *fs_info = inode->root->fs_info; const u32 block_size = fs_info->sectorsize; const u64 range_end = file_offset + block_size - 1; const size_t inline_size = size - btrfs_file_extent_calc_inline_size(0); char *data_start = inline_data + btrfs_file_extent_calc_inline_size(0); struct extent_changeset *data_reserved = NULL; struct page *page = NULL; struct address_space *mapping = inode->vfs_inode.i_mapping; int ret; ASSERT(IS_ALIGNED(file_offset, block_size)); /* * We have flushed and locked the ranges of the source and destination * inodes, we also have locked the inodes, so we are safe to do a * reservation here. Also we must not do the reservation while holding * a transaction open, otherwise we would deadlock. */ ret = btrfs_delalloc_reserve_space(inode, &data_reserved, file_offset, block_size); if (ret) goto out; page = find_or_create_page(mapping, file_offset >> PAGE_SHIFT, btrfs_alloc_write_mask(mapping)); if (!page) { ret = -ENOMEM; goto out_unlock; } ret = set_page_extent_mapped(page); if (ret < 0) goto out_unlock; clear_extent_bit(&inode->io_tree, file_offset, range_end, EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, NULL); ret = btrfs_set_extent_delalloc(inode, file_offset, range_end, 0, NULL); if (ret) goto out_unlock; /* * After dirtying the page our caller will need to start a transaction, * and if we are low on metadata free space, that can cause flushing of * delalloc for all inodes in order to get metadata space released. * However we are holding the range locked for the whole duration of * the clone/dedupe operation, so we may deadlock if that happens and no * other task releases enough space. So mark this inode as not being * possible to flush to avoid such deadlock. We will clear that flag * when we finish cloning all extents, since a transaction is started * after finding each extent to clone. */ set_bit(BTRFS_INODE_NO_DELALLOC_FLUSH, &inode->runtime_flags); if (comp_type == BTRFS_COMPRESS_NONE) { memcpy_to_page(page, offset_in_page(file_offset), data_start, datal); } else { ret = btrfs_decompress(comp_type, data_start, page, offset_in_page(file_offset), inline_size, datal); if (ret) goto out_unlock; flush_dcache_page(page); } /* * If our inline data is smaller then the block/page size, then the * remaining of the block/page is equivalent to zeroes. We had something * like the following done: * * $ xfs_io -f -c "pwrite -S 0xab 0 500" file * $ sync # (or fsync) * $ xfs_io -c "falloc 0 4K" file * $ xfs_io -c "pwrite -S 0xcd 4K 4K" * * So what's in the range [500, 4095] corresponds to zeroes. */ if (datal < block_size) memzero_page(page, datal, block_size - datal); btrfs_folio_set_uptodate(fs_info, page_folio(page), file_offset, block_size); btrfs_folio_clear_checked(fs_info, page_folio(page), file_offset, block_size); btrfs_folio_set_dirty(fs_info, page_folio(page), file_offset, block_size); out_unlock: if (page) { unlock_page(page); put_page(page); } if (ret) btrfs_delalloc_release_space(inode, data_reserved, file_offset, block_size, true); btrfs_delalloc_release_extents(inode, block_size); out: extent_changeset_free(data_reserved); return ret; } /* * Deal with cloning of inline extents. We try to copy the inline extent from * the source inode to destination inode when possible. When not possible we * copy the inline extent's data into the respective page of the inode. */ static int clone_copy_inline_extent(struct inode *dst, struct btrfs_path *path, struct btrfs_key *new_key, const u64 drop_start, const u64 datal, const u64 size, const u8 comp_type, char *inline_data, struct btrfs_trans_handle **trans_out) { struct btrfs_fs_info *fs_info = inode_to_fs_info(dst); struct btrfs_root *root = BTRFS_I(dst)->root; const u64 aligned_end = ALIGN(new_key->offset + datal, fs_info->sectorsize); struct btrfs_trans_handle *trans = NULL; struct btrfs_drop_extents_args drop_args = { 0 }; int ret; struct btrfs_key key; if (new_key->offset > 0) { ret = copy_inline_to_page(BTRFS_I(dst), new_key->offset, inline_data, size, datal, comp_type); goto out; } key.objectid = btrfs_ino(BTRFS_I(dst)); key.type = BTRFS_EXTENT_DATA_KEY; key.offset = 0; ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) { return ret; } else if (ret > 0) { if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) { ret = btrfs_next_leaf(root, path); if (ret < 0) return ret; else if (ret > 0) goto copy_inline_extent; } btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); if (key.objectid == btrfs_ino(BTRFS_I(dst)) && key.type == BTRFS_EXTENT_DATA_KEY) { /* * There's an implicit hole at file offset 0, copy the * inline extent's data to the page. */ ASSERT(key.offset > 0); goto copy_to_page; } } else if (i_size_read(dst) <= datal) { struct btrfs_file_extent_item *ei; ei = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_file_extent_item); /* * If it's an inline extent replace it with the source inline * extent, otherwise copy the source inline extent data into * the respective page at the destination inode. */ if (btrfs_file_extent_type(path->nodes[0], ei) == BTRFS_FILE_EXTENT_INLINE) goto copy_inline_extent; goto copy_to_page; } copy_inline_extent: /* * We have no extent items, or we have an extent at offset 0 which may * or may not be inlined. All these cases are dealt the same way. */ if (i_size_read(dst) > datal) { /* * At the destination offset 0 we have either a hole, a regular * extent or an inline extent larger then the one we want to * clone. Deal with all these cases by copying the inline extent * data into the respective page at the destination inode. */ goto copy_to_page; } /* * Release path before starting a new transaction so we don't hold locks * that would confuse lockdep. */ btrfs_release_path(path); /* * If we end up here it means were copy the inline extent into a leaf * of the destination inode. We know we will drop or adjust at most one * extent item in the destination root. * * 1 unit - adjusting old extent (we may have to split it) * 1 unit - add new extent * 1 unit - inode update */ trans = btrfs_start_transaction(root, 3); if (IS_ERR(trans)) { ret = PTR_ERR(trans); trans = NULL; goto out; } drop_args.path = path; drop_args.start = drop_start; drop_args.end = aligned_end; drop_args.drop_cache = true; ret = btrfs_drop_extents(trans, root, BTRFS_I(dst), &drop_args); if (ret) goto out; ret = btrfs_insert_empty_item(trans, root, path, new_key, size); if (ret) goto out; write_extent_buffer(path->nodes[0], inline_data, btrfs_item_ptr_offset(path->nodes[0], path->slots[0]), size); btrfs_update_inode_bytes(BTRFS_I(dst), datal, drop_args.bytes_found); btrfs_set_inode_full_sync(BTRFS_I(dst)); ret = btrfs_inode_set_file_extent_range(BTRFS_I(dst), 0, aligned_end); out: if (!ret && !trans) { /* * No transaction here means we copied the inline extent into a * page of the destination inode. * * 1 unit to update inode item */ trans = btrfs_start_transaction(root, 1); if (IS_ERR(trans)) { ret = PTR_ERR(trans); trans = NULL; } } if (ret && trans) { btrfs_abort_transaction(trans, ret); btrfs_end_transaction(trans); } if (!ret) *trans_out = trans; return ret; copy_to_page: /* * Release our path because we don't need it anymore and also because * copy_inline_to_page() needs to reserve data and metadata, which may * need to flush delalloc when we are low on available space and * therefore cause a deadlock if writeback of an inline extent needs to * write to the same leaf or an ordered extent completion needs to write * to the same leaf. */ btrfs_release_path(path); ret = copy_inline_to_page(BTRFS_I(dst), new_key->offset, inline_data, size, datal, comp_type); goto out; } /* * Clone a range from inode file to another. * * @src: Inode to clone from * @inode: Inode to clone to * @off: Offset within source to start clone from * @olen: Original length, passed by user, of range to clone * @olen_aligned: Block-aligned value of olen * @destoff: Offset within @inode to start clone * @no_time_update: Whether to update mtime/ctime on the target inode */ static int btrfs_clone(struct inode *src, struct inode *inode, const u64 off, const u64 olen, const u64 olen_aligned, const u64 destoff, int no_time_update) { struct btrfs_fs_info *fs_info = inode_to_fs_info(inode); struct btrfs_path *path = NULL; struct extent_buffer *leaf; struct btrfs_trans_handle *trans; char *buf = NULL; struct btrfs_key key; u32 nritems; int slot; int ret; const u64 len = olen_aligned; u64 last_dest_end = destoff; u64 prev_extent_end = off; ret = -ENOMEM; buf = kvmalloc(fs_info->nodesize, GFP_KERNEL); if (!buf) return ret; path = btrfs_alloc_path(); if (!path) { kvfree(buf); return ret; } path->reada = READA_FORWARD; /* Clone data */ key.objectid = btrfs_ino(BTRFS_I(src)); key.type = BTRFS_EXTENT_DATA_KEY; key.offset = off; while (1) { struct btrfs_file_extent_item *extent; u64 extent_gen; int type; u32 size; struct btrfs_key new_key; u64 disko = 0, diskl = 0; u64 datao = 0, datal = 0; u8 comp; u64 drop_start; /* Note the key will change type as we walk through the tree */ ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path, 0, 0); if (ret < 0) goto out; /* * First search, if no extent item that starts at offset off was * found but the previous item is an extent item, it's possible * it might overlap our target range, therefore process it. */ if (key.offset == off && ret > 0 && path->slots[0] > 0) { btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0] - 1); if (key.type == BTRFS_EXTENT_DATA_KEY) path->slots[0]--; } nritems = btrfs_header_nritems(path->nodes[0]); process_slot: if (path->slots[0] >= nritems) { ret = btrfs_next_leaf(BTRFS_I(src)->root, path); if (ret < 0) goto out; if (ret > 0) break; nritems = btrfs_header_nritems(path->nodes[0]); } leaf = path->nodes[0]; slot = path->slots[0]; btrfs_item_key_to_cpu(leaf, &key, slot); if (key.type > BTRFS_EXTENT_DATA_KEY || key.objectid != btrfs_ino(BTRFS_I(src))) break; ASSERT(key.type == BTRFS_EXTENT_DATA_KEY); extent = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); extent_gen = btrfs_file_extent_generation(leaf, extent); comp = btrfs_file_extent_compression(leaf, extent); type = btrfs_file_extent_type(leaf, extent); if (type == BTRFS_FILE_EXTENT_REG || type == BTRFS_FILE_EXTENT_PREALLOC) { disko = btrfs_file_extent_disk_bytenr(leaf, extent); diskl = btrfs_file_extent_disk_num_bytes(leaf, extent); datao = btrfs_file_extent_offset(leaf, extent); datal = btrfs_file_extent_num_bytes(leaf, extent); } else if (type == BTRFS_FILE_EXTENT_INLINE) { /* Take upper bound, may be compressed */ datal = btrfs_file_extent_ram_bytes(leaf, extent); } /* * The first search might have left us at an extent item that * ends before our target range's start, can happen if we have * holes and NO_HOLES feature enabled. * * Subsequent searches may leave us on a file range we have * processed before - this happens due to a race with ordered * extent completion for a file range that is outside our source * range, but that range was part of a file extent item that * also covered a leading part of our source range. */ if (key.offset + datal <= prev_extent_end) { path->slots[0]++; goto process_slot; } else if (key.offset >= off + len) { break; } prev_extent_end = key.offset + datal; size = btrfs_item_size(leaf, slot); read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf, slot), size); btrfs_release_path(path); memcpy(&new_key, &key, sizeof(new_key)); new_key.objectid = btrfs_ino(BTRFS_I(inode)); if (off <= key.offset) new_key.offset = key.offset + destoff - off; else new_key.offset = destoff; /* * Deal with a hole that doesn't have an extent item that * represents it (NO_HOLES feature enabled). * This hole is either in the middle of the cloning range or at * the beginning (fully overlaps it or partially overlaps it). */ if (new_key.offset != last_dest_end) drop_start = last_dest_end; else drop_start = new_key.offset; if (type == BTRFS_FILE_EXTENT_REG || type == BTRFS_FILE_EXTENT_PREALLOC) { struct btrfs_replace_extent_info clone_info; /* * a | --- range to clone ---| b * | ------------- extent ------------- | */ /* Subtract range b */ if (key.offset + datal > off + len) datal = off + len - key.offset; /* Subtract range a */ if (off > key.offset) { datao += off - key.offset; datal -= off - key.offset; } clone_info.disk_offset = disko; clone_info.disk_len = diskl; clone_info.data_offset = datao; clone_info.data_len = datal; clone_info.file_offset = new_key.offset; clone_info.extent_buf = buf; clone_info.is_new_extent = false; clone_info.update_times = !no_time_update; ret = btrfs_replace_file_extents(BTRFS_I(inode), path, drop_start, new_key.offset + datal - 1, &clone_info, &trans); if (ret) goto out; } else { ASSERT(type == BTRFS_FILE_EXTENT_INLINE); /* * Inline extents always have to start at file offset 0 * and can never be bigger then the sector size. We can * never clone only parts of an inline extent, since all * reflink operations must start at a sector size aligned * offset, and the length must be aligned too or end at * the i_size (which implies the whole inlined data). */ ASSERT(key.offset == 0); ASSERT(datal <= fs_info->sectorsize); if (WARN_ON(type != BTRFS_FILE_EXTENT_INLINE) || WARN_ON(key.offset != 0) || WARN_ON(datal > fs_info->sectorsize)) { ret = -EUCLEAN; goto out; } ret = clone_copy_inline_extent(inode, path, &new_key, drop_start, datal, size, comp, buf, &trans); if (ret) goto out; } btrfs_release_path(path); /* * Whenever we share an extent we update the last_reflink_trans * of each inode to the current transaction. This is needed to * make sure fsync does not log multiple checksum items with * overlapping ranges (because some extent items might refer * only to sections of the original extent). For the destination * inode we do this regardless of the generation of the extents * or even if they are inline extents or explicit holes, to make * sure a full fsync does not skip them. For the source inode, * we only need to update last_reflink_trans in case it's a new * extent that is not a hole or an inline extent, to deal with * the checksums problem on fsync. */ if (extent_gen == trans->transid && disko > 0) BTRFS_I(src)->last_reflink_trans = trans->transid; BTRFS_I(inode)->last_reflink_trans = trans->transid; last_dest_end = ALIGN(new_key.offset + datal, fs_info->sectorsize); ret = clone_finish_inode_update(trans, inode, last_dest_end, destoff, olen, no_time_update); if (ret) goto out; if (new_key.offset + datal >= destoff + len) break; btrfs_release_path(path); key.offset = prev_extent_end; if (fatal_signal_pending(current)) { ret = -EINTR; goto out; } cond_resched(); } ret = 0; if (last_dest_end < destoff + len) { /* * We have an implicit hole that fully or partially overlaps our * cloning range at its end. This means that we either have the * NO_HOLES feature enabled or the implicit hole happened due to * mixing buffered and direct IO writes against this file. */ btrfs_release_path(path); /* * When using NO_HOLES and we are cloning a range that covers * only a hole (no extents) into a range beyond the current * i_size, punching a hole in the target range will not create * an extent map defining a hole, because the range starts at or * beyond current i_size. If the file previously had an i_size * greater than the new i_size set by this clone operation, we * need to make sure the next fsync is a full fsync, so that it * detects and logs a hole covering a range from the current * i_size to the new i_size. If the clone range covers extents, * besides a hole, then we know the full sync flag was already * set by previous calls to btrfs_replace_file_extents() that * replaced file extent items. */ if (last_dest_end >= i_size_read(inode)) btrfs_set_inode_full_sync(BTRFS_I(inode)); ret = btrfs_replace_file_extents(BTRFS_I(inode), path, last_dest_end, destoff + len - 1, NULL, &trans); if (ret) goto out; ret = clone_finish_inode_update(trans, inode, destoff + len, destoff, olen, no_time_update); } out: btrfs_free_path(path); kvfree(buf); clear_bit(BTRFS_INODE_NO_DELALLOC_FLUSH, &BTRFS_I(inode)->runtime_flags); return ret; } static void btrfs_double_extent_unlock(struct inode *inode1, u64 loff1, struct inode *inode2, u64 loff2, u64 len) { unlock_extent(&BTRFS_I(inode1)->io_tree, loff1, loff1 + len - 1, NULL); unlock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1, NULL); } static void btrfs_double_extent_lock(struct inode *inode1, u64 loff1, struct inode *inode2, u64 loff2, u64 len) { u64 range1_end = loff1 + len - 1; u64 range2_end = loff2 + len - 1; if (inode1 < inode2) { swap(inode1, inode2); swap(loff1, loff2); swap(range1_end, range2_end); } else if (inode1 == inode2 && loff2 < loff1) { swap(loff1, loff2); swap(range1_end, range2_end); } lock_extent(&BTRFS_I(inode1)->io_tree, loff1, range1_end, NULL); lock_extent(&BTRFS_I(inode2)->io_tree, loff2, range2_end, NULL); btrfs_assert_inode_range_clean(BTRFS_I(inode1), loff1, range1_end); btrfs_assert_inode_range_clean(BTRFS_I(inode2), loff2, range2_end); } static void btrfs_double_mmap_lock(struct inode *inode1, struct inode *inode2) { if (inode1 < inode2) swap(inode1, inode2); down_write(&BTRFS_I(inode1)->i_mmap_lock); down_write_nested(&BTRFS_I(inode2)->i_mmap_lock, SINGLE_DEPTH_NESTING); } static void btrfs_double_mmap_unlock(struct inode *inode1, struct inode *inode2) { up_write(&BTRFS_I(inode1)->i_mmap_lock); up_write(&BTRFS_I(inode2)->i_mmap_lock); } static int btrfs_extent_same_range(struct inode *src, u64 loff, u64 len, struct inode *dst, u64 dst_loff) { struct btrfs_fs_info *fs_info = BTRFS_I(src)->root->fs_info; const u64 bs = fs_info->sectorsize; int ret; /* * Lock destination range to serialize with concurrent readahead() and * source range to serialize with relocation. */ btrfs_double_extent_lock(src, loff, dst, dst_loff, len); ret = btrfs_clone(src, dst, loff, len, ALIGN(len, bs), dst_loff, 1); btrfs_double_extent_unlock(src, loff, dst, dst_loff, len); btrfs_btree_balance_dirty(fs_info); return ret; } static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen, struct inode *dst, u64 dst_loff) { int ret = 0; u64 i, tail_len, chunk_count; struct btrfs_root *root_dst = BTRFS_I(dst)->root; spin_lock(&root_dst->root_item_lock); if (root_dst->send_in_progress) { btrfs_warn_rl(root_dst->fs_info, "cannot deduplicate to root %llu while send operations are using it (%d in progress)", root_dst->root_key.objectid, root_dst->send_in_progress); spin_unlock(&root_dst->root_item_lock); return -EAGAIN; } root_dst->dedupe_in_progress++; spin_unlock(&root_dst->root_item_lock); tail_len = olen % BTRFS_MAX_DEDUPE_LEN; chunk_count = div_u64(olen, BTRFS_MAX_DEDUPE_LEN); for (i = 0; i < chunk_count; i++) { ret = btrfs_extent_same_range(src, loff, BTRFS_MAX_DEDUPE_LEN, dst, dst_loff); if (ret) goto out; loff += BTRFS_MAX_DEDUPE_LEN; dst_loff += BTRFS_MAX_DEDUPE_LEN; } if (tail_len > 0) ret = btrfs_extent_same_range(src, loff, tail_len, dst, dst_loff); out: spin_lock(&root_dst->root_item_lock); root_dst->dedupe_in_progress--; spin_unlock(&root_dst->root_item_lock); return ret; } static noinline int btrfs_clone_files(struct file *file, struct file *file_src, u64 off, u64 olen, u64 destoff) { struct inode *inode = file_inode(file); struct inode *src = file_inode(file_src); struct btrfs_fs_info *fs_info = inode_to_fs_info(inode); int ret; int wb_ret; u64 len = olen; u64 bs = fs_info->sectorsize; /* * VFS's generic_remap_file_range_prep() protects us from cloning the * eof block into the middle of a file, which would result in corruption * if the file size is not blocksize aligned. So we don't need to check * for that case here. */ if (off + len == src->i_size) len = ALIGN(src->i_size, bs) - off; if (destoff > inode->i_size) { const u64 wb_start = ALIGN_DOWN(inode->i_size, bs); ret = btrfs_cont_expand(BTRFS_I(inode), inode->i_size, destoff); if (ret) return ret; /* * We may have truncated the last block if the inode's size is * not sector size aligned, so we need to wait for writeback to * complete before proceeding further, otherwise we can race * with cloning and attempt to increment a reference to an * extent that no longer exists (writeback completed right after * we found the previous extent covering eof and before we * attempted to increment its reference count). */ ret = btrfs_wait_ordered_range(inode, wb_start, destoff - wb_start); if (ret) return ret; } /* * Lock destination range to serialize with concurrent readahead() and * source range to serialize with relocation. */ btrfs_double_extent_lock(src, off, inode, destoff, len); ret = btrfs_clone(src, inode, off, olen, len, destoff, 0); btrfs_double_extent_unlock(src, off, inode, destoff, len); /* * We may have copied an inline extent into a page of the destination * range, so wait for writeback to complete before truncating pages * from the page cache. This is a rare case. */ wb_ret = btrfs_wait_ordered_range(inode, destoff, len); ret = ret ? ret : wb_ret; /* * Truncate page cache pages so that future reads will see the cloned * data immediately and not the previous data. */ truncate_inode_pages_range(&inode->i_data, round_down(destoff, PAGE_SIZE), round_up(destoff + len, PAGE_SIZE) - 1); btrfs_btree_balance_dirty(fs_info); return ret; } static int btrfs_remap_file_range_prep(struct file *file_in, loff_t pos_in, struct file *file_out, loff_t pos_out, loff_t *len, unsigned int remap_flags) { struct inode *inode_in = file_inode(file_in); struct inode *inode_out = file_inode(file_out); u64 bs = BTRFS_I(inode_out)->root->fs_info->sectorsize; u64 wb_len; int ret; if (!(remap_flags & REMAP_FILE_DEDUP)) { struct btrfs_root *root_out = BTRFS_I(inode_out)->root; if (btrfs_root_readonly(root_out)) return -EROFS; ASSERT(inode_in->i_sb == inode_out->i_sb); } /* Don't make the dst file partly checksummed */ if ((BTRFS_I(inode_in)->flags & BTRFS_INODE_NODATASUM) != (BTRFS_I(inode_out)->flags & BTRFS_INODE_NODATASUM)) { return -EINVAL; } /* * Now that the inodes are locked, we need to start writeback ourselves * and can not rely on the writeback from the VFS's generic helper * generic_remap_file_range_prep() because: * * 1) For compression we must call filemap_fdatawrite_range() range * twice (btrfs_fdatawrite_range() does it for us), and the generic * helper only calls it once; * * 2) filemap_fdatawrite_range(), called by the generic helper only * waits for the writeback to complete, i.e. for IO to be done, and * not for the ordered extents to complete. We need to wait for them * to complete so that new file extent items are in the fs tree. */ if (*len == 0 && !(remap_flags & REMAP_FILE_DEDUP)) wb_len = ALIGN(inode_in->i_size, bs) - ALIGN_DOWN(pos_in, bs); else wb_len = ALIGN(*len, bs); /* * Workaround to make sure NOCOW buffered write reach disk as NOCOW. * * Btrfs' back references do not have a block level granularity, they * work at the whole extent level. * NOCOW buffered write without data space reserved may not be able * to fall back to CoW due to lack of data space, thus could cause * data loss. * * Here we take a shortcut by flushing the whole inode, so that all * nocow write should reach disk as nocow before we increase the * reference of the extent. We could do better by only flushing NOCOW * data, but that needs extra accounting. * * Also we don't need to check ASYNC_EXTENT, as async extent will be * CoWed anyway, not affecting nocow part. */ ret = filemap_flush(inode_in->i_mapping); if (ret < 0) return ret; ret = btrfs_wait_ordered_range(inode_in, ALIGN_DOWN(pos_in, bs), wb_len); if (ret < 0) return ret; ret = btrfs_wait_ordered_range(inode_out, ALIGN_DOWN(pos_out, bs), wb_len); if (ret < 0) return ret; return generic_remap_file_range_prep(file_in, pos_in, file_out, pos_out, len, remap_flags); } static bool file_sync_write(const struct file *file) { if (file->f_flags & (__O_SYNC | O_DSYNC)) return true; if (IS_SYNC(file_inode(file))) return true; return false; } loff_t btrfs_remap_file_range(struct file *src_file, loff_t off, struct file *dst_file, loff_t destoff, loff_t len, unsigned int remap_flags) { struct inode *src_inode = file_inode(src_file); struct inode *dst_inode = file_inode(dst_file); bool same_inode = dst_inode == src_inode; int ret; if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY)) return -EINVAL; if (same_inode) { btrfs_inode_lock(BTRFS_I(src_inode), BTRFS_ILOCK_MMAP); } else { lock_two_nondirectories(src_inode, dst_inode); btrfs_double_mmap_lock(src_inode, dst_inode); } ret = btrfs_remap_file_range_prep(src_file, off, dst_file, destoff, &len, remap_flags); if (ret < 0 || len == 0) goto out_unlock; if (remap_flags & REMAP_FILE_DEDUP) ret = btrfs_extent_same(src_inode, off, len, dst_inode, destoff); else ret = btrfs_clone_files(dst_file, src_file, off, len, destoff); out_unlock: if (same_inode) { btrfs_inode_unlock(BTRFS_I(src_inode), BTRFS_ILOCK_MMAP); } else { btrfs_double_mmap_unlock(src_inode, dst_inode); unlock_two_nondirectories(src_inode, dst_inode); } /* * If either the source or the destination file was opened with O_SYNC, * O_DSYNC or has the S_SYNC attribute, fsync both the destination and * source files/ranges, so that after a successful return (0) followed * by a power failure results in the reflinked data to be readable from * both files/ranges. */ if (ret == 0 && len > 0 && (file_sync_write(src_file) || file_sync_write(dst_file))) { ret = btrfs_sync_file(src_file, off, off + len - 1, 0); if (ret == 0) ret = btrfs_sync_file(dst_file, destoff, destoff + len - 1, 0); } return ret < 0 ? ret : len; }
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