Merge branch 'fix/fst-sysfs' of...

Merge branch 'fix/fst-sysfs' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.5
Signed-off-by: NChris Mason <clm@fb.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

@@ -1459,6 +1459,8 @@ 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;
@@ -4067,6 +4069,8 @@ 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"
@@ -485,6 +486,9 @@ 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);
 				no_compress = 0;
 			} else if (strncmp(args[0].from, "no", 2) == 0) {
 				compress_type = "no";

fs/btrfs/sysfs.c

@@ -202,6 +202,7 @@ BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF);
 BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56);
 BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA);
 BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES);
+BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE);
 
 static struct attribute *btrfs_supported_feature_attrs[] = {
 	BTRFS_FEAT_ATTR_PTR(mixed_backref),
@@ -213,6 +214,7 @@ static struct attribute *btrfs_supported_feature_attrs[] = {
 	BTRFS_FEAT_ATTR_PTR(raid56),
 	BTRFS_FEAT_ATTR_PTR(skinny_metadata),
 	BTRFS_FEAT_ATTR_PTR(no_holes),
+	BTRFS_FEAT_ATTR_PTR(free_space_tree),
 	NULL
 };
 
@@ -780,6 +782,36 @@ int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
 	return error;
 }
 
+
+/*
+ * Change per-fs features in /sys/fs/btrfs/UUID/features to match current
+ * values in superblock. Call after any changes to incompat/compat_ro flags
+ */
+void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info,
+		u64 bit, enum btrfs_feature_set set)
+{
+	struct btrfs_fs_devices *fs_devs;
+	struct kobject *fsid_kobj;
+	u64 features;
+	int ret;
+
+	if (!fs_info)
+		return;
+
+	features = get_features(fs_info, set);
+	ASSERT(bit & supported_feature_masks[set]);
+
+	fs_devs = fs_info->fs_devices;
+	fsid_kobj = &fs_devs->fsid_kobj;
+
+	/*
+	 * FIXME: this is too heavy to update just one value, ideally we'd like
+	 * to use sysfs_update_group but some refactoring is needed first.
+	 */
+	sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
+	ret = sysfs_create_group(fsid_kobj, &btrfs_feature_attr_group);
+}
+
 static int btrfs_init_debugfs(void)
 {
 #ifdef CONFIG_DEBUG_FS

fs/btrfs/sysfs.h

@@ -56,7 +56,7 @@ static struct btrfs_feature_attr btrfs_attr_##_name = {			     \
 #define BTRFS_FEAT_ATTR_COMPAT(name, feature) \
 	BTRFS_FEAT_ATTR(name, FEAT_COMPAT, BTRFS_FEATURE_COMPAT, feature)
 #define BTRFS_FEAT_ATTR_COMPAT_RO(name, feature) \
-	BTRFS_FEAT_ATTR(name, FEAT_COMPAT_RO, BTRFS_FEATURE_COMPAT, feature)
+	BTRFS_FEAT_ATTR(name, FEAT_COMPAT_RO, BTRFS_FEATURE_COMPAT_RO, feature)
 #define BTRFS_FEAT_ATTR_INCOMPAT(name, feature) \
 	BTRFS_FEAT_ATTR(name, FEAT_INCOMPAT, BTRFS_FEATURE_INCOMPAT, feature)
 
@@ -90,4 +90,7 @@ int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs,
 				struct kobject *parent);
 int btrfs_sysfs_add_device(struct btrfs_fs_devices *fs_devs);
 void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs);
+void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info,
+		u64 bit, enum btrfs_feature_set set);
+
 #endif /* _BTRFS_SYSFS_H_ */

fs/btrfs/volumes.c

@@ -4469,6 +4469,8 @@ 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)		\