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btrfs: property: Set incompat flag if lzo/zstd compression is set 

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: 5c1aab1dd5 ("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>
This commit is contained in:
Misono Tomohiro 2018-05-15 16:51:26 +09:00 committed by David Sterba
parent 31d11b83b9
commit 1a63c198dd
1 changed files with 8 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
fs/btrfs/props.c
View File

@ -380,6 +380,7 @@ static int prop_compression_apply(struct inode *inode,
const char *value,
size_t len)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
int type;
if (len == 0) {
@ -390,14 +391,17 @@ static int prop_compression_apply(struct inode *inode,
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;