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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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26
fs/btrfs/ctree.h
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@@ -2428,32 +2428,6 @@ static inline u32 btrfs_file_extent_inline_item_len(
return btrfs_item_size(eb, e) - BTRFS_FILE_EXTENT_INLINE_DATA_START;
}
/* this returns the number of file bytes represented by the inline item.
* If an item is compressed, this is the uncompressed size
*/
static inline u32 btrfs_file_extent_inline_len(const struct extent_buffer *eb,
int slot,
const struct btrfs_file_extent_item *fi)
{
struct btrfs_map_token token;
btrfs_init_map_token(&token);
/*
* return the space used on disk if this item isn't
* compressed or encoded
*/
if (btrfs_token_file_extent_compression(eb, fi, &token) == 0 &&
btrfs_token_file_extent_encryption(eb, fi, &token) == 0 &&
btrfs_token_file_extent_other_encoding(eb, fi, &token) == 0) {
return btrfs_file_extent_inline_item_len(eb,
btrfs_item_nr(slot));
}
/* otherwise use the ram bytes field */
return btrfs_token_file_extent_ram_bytes(eb, fi, &token);
}
/* btrfs_dev_stats_item */
static inline u64 btrfs_dev_stats_value(const struct extent_buffer *eb,
const struct btrfs_dev_stats_item *ptr,