iMX/i2som-imx-linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

btrfs: compression: don't try to compress if we don't have enough pages

Browse Source 
commit f216562731 upstream

The early check if we should attempt compression does not take into
account the number of input pages. It can happen that there's only one
page, eg. a tail page after some ranges of the BTRFS_MAX_UNCOMPRESSED
have been processed, or an isolated page that won't be converted to an
inline extent.

The single page would be compressed but a later check would drop it
again because the result size must be at least one block shorter than
the input. That can never work with just one page.

CC: stable@vger.kernel.org # 4.4+
Signed-off-by: David Sterba <dsterba@suse.com>
[sudip: adjust context]
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
David Sterba
2021-06-14 12:45:18 +02:00
committed by Greg Kroah-Hartman
parent 654d3d1e01
commit 94e5a12759
1 changed files with 1 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
fs/btrfs/inode.c
View File

@ -540,7 +540,7 @@ again:
* inode has not been flagged as nocompress. This flag can
* change at any time if we discover bad compression ratios.
*/
if (inode_need_compress(inode, start, end)) {
if (nr_pages > 1 && inode_need_compress(inode, start, end)) {
WARN_ON(pages);
pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
if (!pages) {