Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit a7164fa4 authored Jul 17, 2017 by David Sterba

btrfs: prepare for extensions in compression options



This is a minimal patch intended to be backported to older kernels.
We're going to extend the string specifying the compression method and
this would fail on kernels before that change (the string is compared
exactly).

Relax the string matching only to the prefix, ie. ignoring anything that
goes after "zlib" or "lzo", regardless of th format extension we decide
to use. This applies to the mount options and properties.

That way, patched old kernels could be booted on systems already
utilizing the new compression spec.

Applicable since commit 63541927, v3.14.

Signed-off-by: David Sterba <dsterba@suse.com>

parent 1e20d1c4

fs/btrfs/props.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -408,9 +408,9 @@ static int prop_compression_apply(struct inode *inode,
		return 0;
		}

		if (!strncmp("lzo", value, len))
		if (!strncmp("lzo", value, 3))
		type = BTRFS_COMPRESS_LZO;
		else if (!strncmp("zlib", value, len))
		else if (!strncmp("zlib", value, 4))
		type = BTRFS_COMPRESS_ZLIB;
		else
		return -EINVAL;

fs/btrfs/super.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -499,14 +499,14 @@ int btrfs_parse_options(struct btrfs_fs_info info, char options,
		btrfs_test_opt(info, FORCE_COMPRESS);
		if (token == Opt_compress \|\|
		token == Opt_compress_force \|\|
		strcmp(args[0].from, "zlib") == 0) {
		strncmp(args[0].from, "zlib", 4) == 0) {
		compress_type = "zlib";
		info->compress_type = BTRFS_COMPRESS_ZLIB;
		btrfs_set_opt(info->mount_opt, COMPRESS);
		btrfs_clear_opt(info->mount_opt, NODATACOW);
		btrfs_clear_opt(info->mount_opt, NODATASUM);
		no_compress = 0;
		} else if (strcmp(args[0].from, "lzo") == 0) {
		} else if (strncmp(args[0].from, "lzo", 3) == 0) {
		compress_type = "lzo";
		info->compress_type = BTRFS_COMPRESS_LZO;
		btrfs_set_opt(info->mount_opt, COMPRESS);