btrfs: synchronize incompat feature bits with sysfs files

The files under /sys/fs/UUID/features get out of sync with the actual
incompat bits set for the filesystem if they change after mount (eg. the
LZO compression).

Synchronize the feature bits with the sysfs files representing them
right after we set/clear them.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

fs/btrfs/free-space-tree.c

@@ -23,6 +23,7 @@
 #include "locking.h"
 #include "free-space-tree.h"
 #include "transaction.h"
+#include "sysfs.h"
 
 static int __add_block_group_free_space(struct btrfs_trans_handle *trans,
 					struct btrfs_fs_info *fs_info,
@@ -1169,6 +1170,9 @@ int btrfs_create_free_space_tree(struct btrfs_fs_info *fs_info)
 	}
 
 	btrfs_set_fs_compat_ro(fs_info, FREE_SPACE_TREE);
+	btrfs_sysfs_feature_update(fs_info,
+		BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE, FEAT_COMPAT_RO);
+
 	fs_info->creating_free_space_tree = 0;
 
 	ret = btrfs_commit_transaction(trans, tree_root);
@@ -1237,6 +1241,9 @@ int btrfs_clear_free_space_tree(struct btrfs_fs_info *fs_info)
 		return PTR_ERR(trans);
 
 	btrfs_clear_fs_compat_ro(fs_info, FREE_SPACE_TREE);
+	btrfs_sysfs_feature_update(fs_info,
+		BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE, FEAT_COMPAT_RO);
+
 	fs_info->free_space_root = NULL;
 
 	ret = clear_free_space_tree(trans, free_space_root);

fs/btrfs/ioctl.c

@@ -1455,6 +1455,8 @@ int btrfs_defrag_file(struct inode *inode, struct file *file,
 
 	if (range->compress_type == BTRFS_COMPRESS_LZO) {
 		btrfs_set_fs_incompat(root->fs_info, COMPRESS_LZO);
+		btrfs_sysfs_feature_update(root->fs_info,
+			BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO, FEAT_INCOMPAT);
 	}
 
 	ret = defrag_count;
@@ -4063,6 +4065,8 @@ static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
 	btrfs_free_path(path);
 
 	btrfs_set_fs_incompat(root->fs_info, DEFAULT_SUBVOL);
+	btrfs_sysfs_feature_update(root->fs_info,
+		BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL, FEAT_INCOMPAT);
 	btrfs_end_transaction(trans, root);
 out:
 	mnt_drop_write_file(file);

fs/btrfs/super.c

@@ -58,6 +58,7 @@
 #include "dev-replace.h"
 #include "free-space-cache.h"
 #include "backref.h"
+#include "sysfs.h"
 #include "tests/btrfs-tests.h"
 
 #include "qgroup.h"
@@ -477,6 +478,9 @@ 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);
+				btrfs_sysfs_feature_update(root->fs_info,
+					BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO,
+					FEAT_INCOMPAT);
 			} else if (strncmp(args[0].from, "no", 2) == 0) {
 				compress_type = "no";
 				btrfs_clear_opt(info->mount_opt, COMPRESS);

fs/btrfs/volumes.c

@@ -4468,6 +4468,8 @@ static void check_raid56_incompat_flag(struct btrfs_fs_info *info, u64 type)
 		return;
 
 	btrfs_set_fs_incompat(info, RAID56);
+	btrfs_sysfs_feature_update(info, BTRFS_FEATURE_INCOMPAT_RAID56,
+		FEAT_INCOMPAT);
 }
 
 #define BTRFS_MAX_DEVS(r) ((BTRFS_LEAF_DATA_SIZE(r)		\