4.14-stable review patch. If anyone has any objections, please let me know.
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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;