[3/5] Btrfs: add SNAP_CREATE_ASYNC ioctl

Commit Message

Sage Weil March 22, 2010, 7:13 p.m. UTC

None

Patch

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 8e29712..7ea4ff0 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -224,7 +224,8 @@  static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
 
 static noinline int create_subvol(struct btrfs_root *root,
 				  struct dentry *dentry,
-				  char *name, int namelen)
+				  char *name, int namelen,
+				  u64 *async_transid)
 {
 	struct btrfs_trans_handle *trans;
 	struct btrfs_key key;
@@ -342,7 +343,12 @@  static noinline int create_subvol(struct btrfs_root *root,
 
 	d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry));
 fail:
-	err = btrfs_commit_transaction(trans, root);
+	if (async_transid) {
+		*async_transid = trans->transid;
+		err = btrfs_commit_transaction_async(trans, root, 1);
+	} else {
+		err = btrfs_commit_transaction(trans, root);
+	}
 	if (err && !ret)
 		ret = err;
 
@@ -351,7 +357,7 @@  fail:
 }
 
 static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
-			   char *name, int namelen)
+			   char *name, int namelen, u64 *async_transid)
 {
 	struct inode *inode;
 	struct btrfs_pending_snapshot *pending_snapshot;
@@ -392,7 +398,12 @@  static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
 	pending_snapshot->root = root;
 	list_add(&pending_snapshot->list,
 		 &trans->transaction->pending_snapshots);
-	ret = btrfs_commit_transaction(trans, root);
+	if (async_transid) {
+		*async_transid = trans->transid;
+		ret = btrfs_commit_transaction_async(trans, root, 1);
+	} else {
+		ret = btrfs_commit_transaction(trans, root);
+	}
 	BUG_ON(ret);
 	btrfs_unreserve_metadata_space(root, 6);
 
@@ -425,7 +436,8 @@  static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
  */
 static noinline int btrfs_mksubvol(struct path *parent,
 				   char *name, int namelen,
-				   struct btrfs_root *snap_src)
+				   struct btrfs_root *snap_src,
+				   u64 *async_transid)
 {
 	struct inode *dir  = parent->dentry->d_inode;
 	struct dentry *dentry;
@@ -457,10 +469,10 @@  static noinline int btrfs_mksubvol(struct path *parent,
 
 	if (snap_src) {
 		error = create_snapshot(snap_src, dentry,
-					name, namelen);
+					name, namelen, async_transid);
 	} else {
 		error = create_subvol(BTRFS_I(dir)->root, dentry,
-				      name, namelen);
+				      name, namelen, async_transid);
 	}
 	if (!error)
 		fsnotify_mkdir(dir, dentry);
@@ -825,12 +837,14 @@  out_unlock:
 }
 
 static noinline int btrfs_ioctl_snap_create(struct file *file,
-					    void __user *arg, int subvol)
+					    void __user *arg, int subvol,
+					    int async)
 {
 	struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
 	struct btrfs_ioctl_vol_args *vol_args;
 	struct file *src_file;
 	int namelen;
+	u64 transid = 0;
 	int ret = 0;
 
 	if (root->fs_info->sb->s_flags & MS_RDONLY)
@@ -849,7 +863,7 @@  static noinline int btrfs_ioctl_snap_create(struct file *file,
 
 	if (subvol) {
 		ret = btrfs_mksubvol(&file->f_path, vol_args->name, namelen,
-				     NULL);
+				     NULL, async ? &transid : NULL);
 	} else {
 		struct inode *src_inode;
 		src_file = fget(vol_args->fd);
@@ -867,7 +881,8 @@  static noinline int btrfs_ioctl_snap_create(struct file *file,
 			goto out;
 		}
 		ret = btrfs_mksubvol(&file->f_path, vol_args->name, namelen,
-				     BTRFS_I(src_inode)->root);
+				     BTRFS_I(src_inode)->root,
+				     async ? &transid : NULL);
 		fput(src_file);
 	}
 out:
@@ -2009,9 +2024,11 @@  long btrfs_ioctl(struct file *file, unsigned int
 	case FS_IOC_GETVERSION:
 		return btrfs_ioctl_getversion(file, argp);
 	case BTRFS_IOC_SNAP_CREATE:
-		return btrfs_ioctl_snap_create(file, argp, 0);
+		return btrfs_ioctl_snap_create(file, argp, 0, 0);
+	case BTRFS_IOC_SNAP_CREATE_ASYNC:
+		return btrfs_ioctl_snap_create(file, argp, 0, 1);
 	case BTRFS_IOC_SUBVOL_CREATE:
-		return btrfs_ioctl_snap_create(file, argp, 1);
+		return btrfs_ioctl_snap_create(file, argp, 1, 0);
 	case BTRFS_IOC_SNAP_DESTROY:
 		return btrfs_ioctl_snap_destroy(file, argp);
 	case BTRFS_IOC_DEFAULT_SUBVOL:
diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
index e9a2f7e..d9169d8 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -180,4 +180,6 @@  struct btrfs_ioctl_space_args {
 				    struct btrfs_ioctl_space_args)
 #define BTRFS_IOC_START_SYNC _IOR(BTRFS_IOCTL_MAGIC, 21, __u64)
 #define BTRFS_IOC_WAIT_SYNC  _IOW(BTRFS_IOCTL_MAGIC, 22, __u64)
+#define BTRFS_IOC_SNAP_CREATE_ASYNC _IOW(BTRFS_IOCTL_MAGIC, 23, \
+				   struct btrfs_ioctl_vol_args)
 #endif