Btrfs: allow mount -o remount,compress=no (063849ea) · Commits · 戴 / test

Btrfs allows to turn on compression on a mounted and used filesystem by issuing mount -o remount,compress=lzo. This patch allows to turn compression off again while the filesystem is mounted. As suggested by David Sterba if the compress-force option was set, it is implicitly cleared if compression is turned off. Tested-by:

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

Arnd Hannemann <arnd@arndnet.de>

fs/btrfs/super.c

+8 −1

Original line number	Diff line number	Diff line
		@@ -396,15 +396,22 @@ int btrfs_parse_options(struct btrfs_root root, char options)
		strcmp(args[0].from, "zlib") == 0) {
		compress_type = "zlib";
		info->compress_type = BTRFS_COMPRESS_ZLIB;
		btrfs_set_opt(info->mount_opt, COMPRESS);
		} else if (strcmp(args[0].from, "lzo") == 0) {
		compress_type = "lzo";
		info->compress_type = BTRFS_COMPRESS_LZO;
		btrfs_set_opt(info->mount_opt, COMPRESS);
		} else if (strncmp(args[0].from, "no", 2) == 0) {
		compress_type = "no";
		info->compress_type = BTRFS_COMPRESS_NONE;
		btrfs_clear_opt(info->mount_opt, COMPRESS);
		btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
		compress_force = false;
		} else {
		ret = -EINVAL;
		goto out;
		}

		btrfs_set_opt(info->mount_opt, COMPRESS);
		if (compress_force) {
		btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
		pr_info("btrfs: force %s compression\n",

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