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btrfs: Get rid of the confusing btrfs_file_extent_inline_len

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We used to call btrfs_file_extent_inline_len() to get the uncompressed
data size of an inlined extent.

However this function is hiding evil, for compressed extent, it has no
choice but to directly read out ram_bytes from btrfs_file_extent_item.
While for uncompressed extent, it uses item size to calculate the real
data size, and ignoring ram_bytes completely.

In fact, for corrupted ram_bytes, due to above behavior kernel
btrfs_print_leaf() can't even print correct ram_bytes to expose the bug.

Since we have the tree-checker to verify all EXTENT_DATA, such mismatch
can be detected pretty easily, thus we can trust ram_bytes without the
evil btrfs_file_extent_inline_len().

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Qu Wenruo
2018-06-06 15:41:49 +08:00
committed by David Sterba
parent bc877d285c
commit e41ca58974
8 changed files with 22 additions and 56 deletions
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12
fs/btrfs/inode.c
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@@ -1443,8 +1443,7 @@ next_slot:
nocow = 1;
} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
extent_end = found_key.offset +
btrfs_file_extent_inline_len(leaf,
path->slots[0], fi);
btrfs_file_extent_ram_bytes(leaf, fi);
extent_end = ALIGN(extent_end,
fs_info->sectorsize);
} else {
@@ -4643,8 +4642,8 @@ search_again:
BTRFS_I(inode), leaf, fi,
found_key.offset);
} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
item_end += btrfs_file_extent_inline_len(leaf,
path->slots[0], fi);
item_end += btrfs_file_extent_ram_bytes(leaf,
fi);
trace_btrfs_truncate_show_fi_inline(
BTRFS_I(inode), leaf, fi, path->slots[0],
@@ -6943,7 +6942,8 @@ struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
extent_start);
} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
size_t size;
size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
size = btrfs_file_extent_ram_bytes(leaf, item);
extent_end = ALIGN(extent_start + size,
fs_info->sectorsize);
@@ -6994,7 +6994,7 @@ next:
if (new_inline)
goto out;
size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
size = btrfs_file_extent_ram_bytes(leaf, item);
extent_offset = page_offset(page) + pg_offset - extent_start;
copy_size = min_t(u64, PAGE_SIZE - pg_offset,
size - extent_offset);