Btrfs: fix output of compression message in btrfs_parse_options()

The compression message might not be correctly output.
Fix it.

[[before fix]]

# mount -o compress /dev/sdb3 /test3
[  996.874264] BTRFS info (device sdb3): disk space caching is enabled
[  996.874268] BTRFS: has skinny extents
# mount | grep /test3
/dev/sdb3 on /test3 type btrfs (rw,relatime,compress=zlib,space_cache,subvolid=5,subvol=/)

# mount -o remount,compress-force /dev/sdb3 /test3
[ 1035.075017] BTRFS info (device sdb3): force zlib compression
[ 1035.075021] BTRFS info (device sdb3): disk space caching is enabled
# mount | grep /test3
/dev/sdb3 on /test3 type btrfs (rw,relatime,compress-force=zlib,space_cache,subvolid=5,subvol=/)

# mount -o remount,compress /dev/sdb3 /test3
[ 1053.679092] BTRFS info (device sdb3): disk space caching is enabled
# mount | grep /test3
/dev/sdb3 on /test3 type btrfs (rw,relatime,compress=zlib,space_cache,subvolid=5,subvol=/)

[[after fix]]

# mount -o compress /dev/sdb3 /test3
[  401.021753] BTRFS info (device sdb3): use zlib compression
[  401.021758] BTRFS info (device sdb3): disk space caching is enabled
[  401.021760] BTRFS: has skinny extents
# mount | grep /test3
/dev/sdb3 on /test3 type btrfs (rw,relatime,compress=zlib,space_cache,subvolid=5,subvol=/)

# mount -o remount,compress-force /dev/sdb3 /test3
[  439.824624] BTRFS info (device sdb3): force zlib compression
[  439.824629] BTRFS info (device sdb3): disk space caching is enabled
# mount | grep /test3
/dev/sdb3 on /test3 type btrfs (rw,relatime,compress-force=zlib,space_cache,subvolid=5,subvol=/)

# mount -o remount,compress /dev/sdb3 /test3
[  459.918430] BTRFS info (device sdb3): use zlib compression
[  459.918434] BTRFS info (device sdb3): disk space caching is enabled
# mount | grep /test3
/dev/sdb3 on /test3 type btrfs (rw,relatime,compress=zlib,space_cache,subvolid=5,subvol=/)

Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 5099e4633e5076fb500051913fa2854b1ca16064..3225ac36540843d58c75fef396611f184b53f388 100644 (file)
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -381,6 +381,9 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
        int ret = 0;
        char *compress_type;
        bool compress_force = false;
+       enum btrfs_compression_type saved_compress_type;
+       bool saved_compress_force;
+       int no_compress = 0;
 
        cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
        if (cache_gen)
@@ -458,6 +461,10 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
                        /* Fallthrough */
                case Opt_compress:
                case Opt_compress_type:
+                       saved_compress_type = btrfs_test_opt(root, COMPRESS) ?
+                               info->compress_type : BTRFS_COMPRESS_NONE;
+                       saved_compress_force =
+                               btrfs_test_opt(root, FORCE_COMPRESS);
                        if (token == Opt_compress ||
                            token == Opt_compress_force ||
                            strcmp(args[0].from, "zlib") == 0) {
@@ -466,6 +473,7 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
                                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) {
                                compress_type = "lzo";
                                info->compress_type = BTRFS_COMPRESS_LZO;
@@ -473,25 +481,21 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
                                btrfs_clear_opt(info->mount_opt, NODATACOW);
                                btrfs_clear_opt(info->mount_opt, NODATASUM);
                                btrfs_set_fs_incompat(info, COMPRESS_LZO);
+                               no_compress = 0;
                        } else if (strncmp(args[0].from, "no", 2) == 0) {
                                compress_type = "no";
                                btrfs_clear_opt(info->mount_opt, COMPRESS);
                                btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
                                compress_force = false;
+                               no_compress++;
                        } else {
                                ret = -EINVAL;
                                goto out;
                        }
 
                        if (compress_force) {
-                               btrfs_set_and_info(root, FORCE_COMPRESS,
-                                                  "force %s compression",
-                                                  compress_type);
+                               btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
                        } else {
-                               if (!btrfs_test_opt(root, COMPRESS))
-                                       btrfs_info(root->fs_info,
-                                                  "btrfs: use %s compression",
-                                                  compress_type);
                                /*
                                 * If we remount from compress-force=xxx to
                                 * compress=xxx, we need clear FORCE_COMPRESS
@@ -500,6 +504,17 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
                                 */
                                btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
                        }
+                       if ((btrfs_test_opt(root, COMPRESS) &&
+                            (info->compress_type != saved_compress_type ||
+                             compress_force != saved_compress_force)) ||
+                           (!btrfs_test_opt(root, COMPRESS) &&
+                            no_compress == 1)) {
+                               btrfs_info(root->fs_info,
+                                          "%s %s compression",
+                                          (compress_force) ? "force" : "use",
+                                          compress_type);
+                       }
+                       compress_force = false;
                        break;
                case Opt_ssd:
                        btrfs_set_and_info(root, SSD,