diff options
Diffstat (limited to 'fs/btrfs/compression.c')
| -rw-r--r-- | fs/btrfs/compression.c | 39 |
1 files changed, 24 insertions, 15 deletions
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index 7f390849343b..c4444d6f439f 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -1024,6 +1024,7 @@ int btrfs_decompress_buf2page(char *buf, unsigned long buf_start, unsigned long buf_offset; unsigned long current_buf_start; unsigned long start_byte; + unsigned long prev_start_byte; unsigned long working_bytes = total_out - buf_start; unsigned long bytes; char *kaddr; @@ -1071,26 +1072,34 @@ int btrfs_decompress_buf2page(char *buf, unsigned long buf_start, if (!bio->bi_iter.bi_size) return 0; bvec = bio_iter_iovec(bio, bio->bi_iter); - + prev_start_byte = start_byte; start_byte = page_offset(bvec.bv_page) - disk_start; /* - * make sure our new page is covered by this - * working buffer + * We need to make sure we're only adjusting + * our offset into compression working buffer when + * we're switching pages. Otherwise we can incorrectly + * keep copying when we were actually done. */ - if (total_out <= start_byte) - return 1; + if (start_byte != prev_start_byte) { + /* + * make sure our new page is covered by this + * working buffer + */ + if (total_out <= start_byte) + return 1; - /* - * the next page in the biovec might not be adjacent - * to the last page, but it might still be found - * inside this working buffer. bump our offset pointer - */ - if (total_out > start_byte && - current_buf_start < start_byte) { - buf_offset = start_byte - buf_start; - working_bytes = total_out - start_byte; - current_buf_start = buf_start + buf_offset; + /* + * the next page in the biovec might not be adjacent + * to the last page, but it might still be found + * inside this working buffer. bump our offset pointer + */ + if (total_out > start_byte && + current_buf_start < start_byte) { + buf_offset = start_byte - buf_start; + working_bytes = total_out - start_byte; + current_buf_start = buf_start + buf_offset; + } } } |