diff options
| author | Chris Mason <clm@fb.com> | 2014-11-30 08:56:33 -0500 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-11-30 09:33:51 -0800 |
| commit | 2f19cad94cee3c9bd52d0c9ca584ef506302fb7c (patch) | |
| tree | ca1a69874842c86904ff6b66cb7430c818f2baa4 /fs/btrfs/zlib.c | |
| parent | 7a5a4f978750756755dc839014e13d1b088ccc8e (diff) | |
btrfs: zero out left over bytes after processing compression streams
Don Bailey noticed that our page zeroing for compression at end-io time
isn't complete. This reworks a patch from Linus to push the zeroing
into the zlib and lzo specific functions instead of trying to handle the
corners inside btrfs_decompress_buf2page
Signed-off-by: Chris Mason <clm@fb.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Reported-by: Don A. Bailey <donb@securitymouse.com>
cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/btrfs/zlib.c')
| -rw-r--r-- | fs/btrfs/zlib.c | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c index 759fa4e2de8f..fb22fd8d8fb8 100644 --- a/fs/btrfs/zlib.c +++ b/fs/btrfs/zlib.c @@ -299,6 +299,8 @@ done: zlib_inflateEnd(&workspace->strm); if (data_in) kunmap(pages_in[page_in_index]); + if (!ret) + btrfs_clear_biovec_end(bvec, vcnt, page_out_index, pg_offset); return ret; } @@ -310,10 +312,14 @@ static int zlib_decompress(struct list_head *ws, unsigned char *data_in, struct workspace *workspace = list_entry(ws, struct workspace, list); int ret = 0; int wbits = MAX_WBITS; - unsigned long bytes_left = destlen; + unsigned long bytes_left; unsigned long total_out = 0; + unsigned long pg_offset = 0; char *kaddr; + destlen = min_t(unsigned long, destlen, PAGE_SIZE); + bytes_left = destlen; + workspace->strm.next_in = data_in; workspace->strm.avail_in = srclen; workspace->strm.total_in = 0; @@ -341,7 +347,6 @@ static int zlib_decompress(struct list_head *ws, unsigned char *data_in, unsigned long buf_start; unsigned long buf_offset; unsigned long bytes; - unsigned long pg_offset = 0; ret = zlib_inflate(&workspace->strm, Z_NO_FLUSH); if (ret != Z_OK && ret != Z_STREAM_END) @@ -384,6 +389,17 @@ next: ret = 0; zlib_inflateEnd(&workspace->strm); + + /* + * this should only happen if zlib returned fewer bytes than we + * expected. btrfs_get_block is responsible for zeroing from the + * end of the inline extent (destlen) to the end of the page + */ + if (pg_offset < destlen) { + kaddr = kmap_atomic(dest_page); + memset(kaddr + pg_offset, 0, destlen - pg_offset); + kunmap_atomic(kaddr); + } return ret; } |