btrfs: Get rid of the confusing btrfs_file_extent_inline_len

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>

1 files changed, 4 insertions, 8 deletions

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index b3b1d424f2d8..6bca8f88ade0 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -597,7 +597,7 @@ static noinline int replay_one_extent(struct btrfs_trans_handle *trans,
                 if (btrfs_file_extent_disk_bytenr(eb, item) == 0)
                         nbytes = 0;
         } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
-                size = btrfs_file_extent_inline_len(eb, slot, item);
+                size = btrfs_file_extent_ram_bytes(eb, item);
                 nbytes = btrfs_file_extent_ram_bytes(eb, item);
                 extent_end = ALIGN(start + size,
                                    fs_info->sectorsize);
@@ -3920,9 +3920,7 @@ static noinline int copy_items(struct btrfs_trans_handle *trans,
                                         struct btrfs_file_extent_item);
                 if (btrfs_file_extent_type(src, extent) ==
                     BTRFS_FILE_EXTENT_INLINE) {
-                        len = btrfs_file_extent_inline_len(src,
-                                                           src_path->slots[0],
-                                                           extent);
+                        len = btrfs_file_extent_ram_bytes(src, extent);
                         *last_extent = ALIGN(key.offset + len,
                                              fs_info->sectorsize);
                 } else {
@@ -3987,7 +3985,7 @@ fill_holes:
                 extent = btrfs_item_ptr(src, i, struct btrfs_file_extent_item);
                 if (btrfs_file_extent_type(src, extent) ==
                     BTRFS_FILE_EXTENT_INLINE) {
-                        len = btrfs_file_extent_inline_len(src, i, extent);
+                        len = btrfs_file_extent_ram_bytes(src, extent);
                         extent_end = ALIGN(key.offset + len,
                                            fs_info->sectorsize);
                 } else {
@@ -4572,9 +4570,7 @@ static int btrfs_log_trailing_hole(struct btrfs_trans_handle *trans,
 
                 if (btrfs_file_extent_type(leaf, extent) ==
                     BTRFS_FILE_EXTENT_INLINE) {
-                        len = btrfs_file_extent_inline_len(leaf,
-                                                           path->slots[0],
-                                                           extent);
+                        len = btrfs_file_extent_ram_bytes(leaf, extent);
                         ASSERT(len == i_size ||
                                (len == fs_info->sectorsize &&
                                 btrfs_file_extent_compression(leaf, extent) !=