diff options
| -rw-r--r-- | fs/btrfs/btrfs_inode.h | 3 | ||||
| -rw-r--r-- | fs/btrfs/file.c | 33 | ||||
| -rw-r--r-- | fs/btrfs/inode.c | 107 |
3 files changed, 98 insertions, 45 deletions
diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h index a5ebd2b9e242..a79fa0726f1d 100644 --- a/fs/btrfs/btrfs_inode.h +++ b/fs/btrfs/btrfs_inode.h @@ -547,8 +547,7 @@ int btrfs_add_link(struct btrfs_trans_handle *trans, struct btrfs_inode *parent_inode, struct btrfs_inode *inode, const struct fscrypt_str *name, int add_backref, u64 index); int btrfs_delete_subvolume(struct btrfs_inode *dir, struct dentry *dentry); -int btrfs_truncate_block(struct btrfs_inode *inode, loff_t from, loff_t len, - int front); +int btrfs_truncate_block(struct btrfs_inode *inode, u64 offset, u64 start, u64 end); int btrfs_start_delalloc_snapshot(struct btrfs_root *root, bool in_reclaim_context); int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, long nr, diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 42d2df8ebe05..c1b350fd3bb7 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -2611,7 +2611,8 @@ static int btrfs_punch_hole(struct file *file, loff_t offset, loff_t len) u64 lockend; u64 tail_start; u64 tail_len; - u64 orig_start = offset; + const u64 orig_start = offset; + const u64 orig_end = offset + len - 1; int ret = 0; bool same_block; u64 ino_size; @@ -2643,18 +2644,14 @@ static int btrfs_punch_hole(struct file *file, loff_t offset, loff_t len) 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); + ret = btrfs_truncate_block(BTRFS_I(inode), offset + len - 1, + orig_start, orig_end); } else { ret = 0; } @@ -2664,7 +2661,7 @@ static int btrfs_punch_hole(struct file *file, loff_t offset, loff_t len) /* zero back part of the first block */ if (offset < ino_size) { truncated_block = true; - ret = btrfs_truncate_block(BTRFS_I(inode), offset, 0, 0); + ret = btrfs_truncate_block(BTRFS_I(inode), offset, orig_start, orig_end); if (ret) { btrfs_inode_unlock(BTRFS_I(inode), BTRFS_ILOCK_MMAP); return ret; @@ -2701,8 +2698,8 @@ static int btrfs_punch_hole(struct file *file, loff_t offset, loff_t len) if (tail_start + tail_len < ino_size) { truncated_block = true; ret = btrfs_truncate_block(BTRFS_I(inode), - tail_start + tail_len, - 0, 1); + tail_start + tail_len - 1, + orig_start, orig_end); if (ret) goto out_only_mutex; } @@ -2870,6 +2867,8 @@ static int btrfs_zero_range(struct inode *inode, int ret; u64 alloc_hint = 0; const u64 sectorsize = fs_info->sectorsize; + const u64 orig_start = offset; + const u64 orig_end = offset + len - 1; u64 alloc_start = round_down(offset, sectorsize); u64 alloc_end = round_up(offset + len, sectorsize); u64 bytes_to_reserve = 0; @@ -2932,8 +2931,8 @@ static int btrfs_zero_range(struct inode *inode, } if (len < sectorsize && em->disk_bytenr != EXTENT_MAP_HOLE) { btrfs_free_extent_map(em); - ret = btrfs_truncate_block(BTRFS_I(inode), offset, len, - 0); + ret = btrfs_truncate_block(BTRFS_I(inode), offset + len - 1, + orig_start, orig_end); if (!ret) ret = btrfs_fallocate_update_isize(inode, offset + len, @@ -2964,7 +2963,8 @@ static int btrfs_zero_range(struct inode *inode, 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); + ret = btrfs_truncate_block(BTRFS_I(inode), offset, + orig_start, orig_end); if (ret) goto out; } else { @@ -2981,8 +2981,8 @@ static int btrfs_zero_range(struct inode *inode, 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); + ret = btrfs_truncate_block(BTRFS_I(inode), offset + len - 1, + orig_start, orig_end); if (ret) goto out; } else { @@ -3102,7 +3102,8 @@ static long btrfs_fallocate(struct file *file, int mode, * 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); + ret = btrfs_truncate_block(BTRFS_I(inode), inode->i_size, + inode->i_size, (u64)-1); if (ret) goto out; } diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 3a1e5926fee9..db46fda53770 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -4775,20 +4775,34 @@ out_notrans: return ret; } +static bool is_inside_block(u64 bytenr, u64 blockstart, u32 blocksize) +{ + ASSERT(IS_ALIGNED(blockstart, blocksize), "blockstart=%llu blocksize=%u", + blockstart, blocksize); + + if (blockstart <= bytenr && bytenr <= blockstart + blocksize - 1) + return true; + return false; +} + /* - * Read, zero a chunk and write a block. + * Handle the truncation of a fs block. * - * @inode - inode that we're zeroing - * @from - the offset to start zeroing - * @len - the length to zero, 0 to zero the entire range respective to the - * offset - * @front - zero up to the offset instead of from the offset on + * @inode - inode that we're zeroing + * @offset - the file offset of the block to truncate + * The value must be inside [@start, @end], and the function will do + * extra checks if the block that covers @offset needs to be zeroed. + * @start - the start file offset of the range we want to zero + * @end - the end (inclusive) file offset of the range we want to zero. * - * This will find the block for the "from" offset and cow the block and zero the - * part we want to zero. This is used with truncate and hole punching. + * If the range is not block aligned, read out the folio that covers @offset, + * and if needed zero blocks that are inside the folio and covered by [@start, @end). + * If @start or @end + 1 lands inside a block, that block will be marked dirty + * for writeback. + * + * This is utilized by hole punch, zero range, file expansion. */ -int btrfs_truncate_block(struct btrfs_inode *inode, loff_t from, loff_t len, - int front) +int btrfs_truncate_block(struct btrfs_inode *inode, u64 offset, u64 start, u64 end) { struct btrfs_fs_info *fs_info = inode->root->fs_info; struct address_space *mapping = inode->vfs_inode.i_mapping; @@ -4798,20 +4812,49 @@ int btrfs_truncate_block(struct btrfs_inode *inode, loff_t from, loff_t len, struct extent_changeset *data_reserved = NULL; bool only_release_metadata = false; u32 blocksize = fs_info->sectorsize; - pgoff_t index = from >> PAGE_SHIFT; - unsigned offset = from & (blocksize - 1); + pgoff_t index = (offset >> PAGE_SHIFT); struct folio *folio; gfp_t mask = btrfs_alloc_write_mask(mapping); size_t write_bytes = blocksize; int ret = 0; + const bool in_head_block = is_inside_block(offset, round_down(start, blocksize), + blocksize); + const bool in_tail_block = is_inside_block(offset, round_down(end, blocksize), + blocksize); + bool need_truncate_head = false; + bool need_truncate_tail = false; + u64 zero_start; + u64 zero_end; u64 block_start; u64 block_end; - if (IS_ALIGNED(offset, blocksize) && - (!len || IS_ALIGNED(len, blocksize))) + /* @offset should be inside the range. */ + ASSERT(start <= offset && offset <= end, "offset=%llu start=%llu end=%llu", + offset, start, end); + + /* The range is aligned at both ends. */ + if (IS_ALIGNED(start, blocksize) && IS_ALIGNED(end + 1, blocksize)) + goto out; + + /* + * @offset may not be inside the head nor tail block. In that case we + * don't need to do anything. + */ + if (!in_head_block && !in_tail_block) + goto out; + + /* + * Skip the truncatioin if the range in the target block is already aligned. + * The seemingly complex check will also handle the same block case. + */ + if (in_head_block && !IS_ALIGNED(start, blocksize)) + need_truncate_head = true; + if (in_tail_block && !IS_ALIGNED(end + 1, blocksize)) + need_truncate_tail = true; + if (!need_truncate_head && !need_truncate_tail) goto out; - block_start = round_down(from, blocksize); + block_start = round_down(offset, blocksize); block_end = block_start + blocksize - 1; ret = btrfs_check_data_free_space(inode, &data_reserved, block_start, @@ -4891,17 +4934,26 @@ again: goto out_unlock; } - if (offset != blocksize) { - if (!len) - len = blocksize - offset; - if (front) - folio_zero_range(folio, block_start - folio_pos(folio), - offset); - else - folio_zero_range(folio, - (block_start - folio_pos(folio)) + offset, - len); + if (end == (u64)-1) { + /* + * We're truncating beyond EOF, the remaining blocks normally are + * already holes thus no need to zero again, but it's possible for + * fs block size < page size cases to have memory mapped writes + * to pollute ranges beyond EOF. + * + * In that case although such polluted blocks beyond EOF will + * not reach disk, it still affects our page caches. + */ + zero_start = max_t(u64, folio_pos(folio), start); + zero_end = min_t(u64, folio_pos(folio) + folio_size(folio) - 1, + end); + } else { + zero_start = max_t(u64, block_start, start); + zero_end = min_t(u64, block_end, end); } + folio_zero_range(folio, zero_start - folio_pos(folio), + zero_end - zero_start + 1); + btrfs_folio_clear_checked(fs_info, folio, block_start, block_end + 1 - block_start); btrfs_folio_set_dirty(fs_info, folio, block_start, @@ -5003,7 +5055,7 @@ int btrfs_cont_expand(struct btrfs_inode *inode, loff_t oldsize, loff_t size) * rest of the block before we expand the i_size, otherwise we could * expose stale data. */ - ret = btrfs_truncate_block(inode, oldsize, 0, 0); + ret = btrfs_truncate_block(inode, oldsize, oldsize, -1); if (ret) return ret; @@ -7637,7 +7689,8 @@ static int btrfs_truncate(struct btrfs_inode *inode, bool skip_writeback) btrfs_end_transaction(trans); btrfs_btree_balance_dirty(fs_info); - ret = btrfs_truncate_block(inode, inode->vfs_inode.i_size, 0, 0); + ret = btrfs_truncate_block(inode, inode->vfs_inode.i_size, + inode->vfs_inode.i_size, (u64)-1); if (ret) goto out; trans = btrfs_start_transaction(root, 1); |