lkml.org 
[lkml]   [2018]   [May]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.14 43/95] btrfs: property: Set incompat flag if lzo/zstd compression is set
Date
4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>

commit 1a63c198ddb810c790101d693c7071cca703b3c7 upstream.

Incompat flag of LZO/ZSTD compression should be set at:

1. mount time (-o compress/compress-force)
2. when defrag is done
3. when property is set

Currently 3. is missing and this commit adds this.

This could lead to a filesystem that uses ZSTD but is not marked as
such. If a kernel without a ZSTD support encounteres a ZSTD compressed
extent, it will handle that but this could be confusing to the user.

Typically the filesystem is mounted with the ZSTD option, but the
discrepancy can arise when a filesystem is never mounted with ZSTD and
then the property on some file is set (and some new extents are
written). A simple mount with -o compress=zstd will fix that up on an
unpatched kernel.

Same goes for LZO, but this has been around for a very long time
(2.6.37) so it's unlikely that a pre-LZO kernel would be used.

Fixes: 5c1aab1dd544 ("btrfs: Add zstd support")
CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Tomohiro Misono <misono.tomohiro@jp.fujitsu.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add user visible impact ]
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/btrfs/props.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)

--- a/fs/btrfs/props.c
+++ b/fs/btrfs/props.c
@@ -400,6 +400,7 @@ static int prop_compression_apply(struct
const char *value,
size_t len)
{
+ struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
int type;

if (len == 0) {
@@ -410,14 +411,17 @@ static int prop_compression_apply(struct
return 0;
}

- if (!strncmp("lzo", value, 3))
+ if (!strncmp("lzo", value, 3)) {
type = BTRFS_COMPRESS_LZO;
- else if (!strncmp("zlib", value, 4))
+ btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
+ } else if (!strncmp("zlib", value, 4)) {
type = BTRFS_COMPRESS_ZLIB;
- else if (!strncmp("zstd", value, len))
+ } else if (!strncmp("zstd", value, len)) {
type = BTRFS_COMPRESS_ZSTD;
- else
+ btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD);
+ } else {
return -EINVAL;
+ }

BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;

\
 
 \ /
  Last update: 2018-05-22 00:12    [W:0.313 / U:1.036 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site