diff options
Diffstat (limited to 'fs/btrfs/compression.c')
| -rw-r--r-- | fs/btrfs/compression.c | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index 7f11ef559be6..56d970434b4b 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -1138,6 +1138,22 @@ void __cold btrfs_exit_compress(void) } /* + * The bvec is a single page bvec from a bio that contains folios from a filemap. + * + * Since the folio may be a large one, and if the bv_page is not a head page of + * a large folio, then page->index is unreliable. + * + * Thus we need this helper to grab the proper file offset. + */ +static u64 file_offset_from_bvec(const struct bio_vec *bvec) +{ + const struct page *page = bvec->bv_page; + const struct folio *folio = page_folio(page); + + return (page_pgoff(folio, page) << PAGE_SHIFT) + bvec->bv_offset; +} + +/* * Copy decompressed data from working buffer to pages. * * @buf: The decompressed data buffer @@ -1188,7 +1204,7 @@ int btrfs_decompress_buf2page(const char *buf, u32 buf_len, * cb->start may underflow, but subtracting that value can still * give us correct offset inside the full decompressed extent. */ - bvec_offset = page_offset(bvec.bv_page) + bvec.bv_offset - cb->start; + bvec_offset = file_offset_from_bvec(&bvec) - cb->start; /* Haven't reached the bvec range, exit */ if (decompressed + buf_len <= bvec_offset) |