diff mbox

[4/6] Btrfs: add SNAP_CREATE_ASYNC ioctl

Message ID 1288033662-21464-5-git-send-email-sage@newdream.net
State New, archived
Headers show

Commit Message

Sage Weil Oct. 25, 2010, 7:07 p.m. UTC
None
diff mbox

Patch

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 6306051..679b8a8 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;
@@ -338,13 +339,19 @@  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;
 	return ret;
 }
 
-static int create_snapshot(struct btrfs_root *root, struct dentry *dentry)
+static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
+			   char *name, int namelen, u64 *async_transid)
 {
 	struct inode *inode;
 	struct btrfs_pending_snapshot *pending_snapshot;
@@ -373,7 +380,14 @@  static int create_snapshot(struct btrfs_root *root, struct dentry *dentry)
 
 	list_add(&pending_snapshot->list,
 		 &trans->transaction->pending_snapshots);
-	ret = btrfs_commit_transaction(trans, root->fs_info->extent_root);
+	if (async_transid) {
+		*async_transid = trans->transid;
+		ret = btrfs_commit_transaction_async(trans,
+				     root->fs_info->extent_root, 1);
+	} else {
+		ret = btrfs_commit_transaction(trans,
+					       root->fs_info->extent_root);
+	}
 	BUG_ON(ret);
 
 	ret = pending_snapshot->error;
@@ -412,7 +426,8 @@  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;
@@ -443,10 +458,11 @@  static noinline int btrfs_mksubvol(struct path *parent,
 		goto out_up_read;
 
 	if (snap_src) {
-		error = create_snapshot(snap_src, dentry);
+		error = create_snapshot(snap_src, dentry,
+					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);
@@ -801,8 +817,10 @@  out_unlock:
 	return ret;
 }
 
-static noinline int btrfs_ioctl_snap_create(struct file *file,
-					    void __user *arg, int subvol)
+static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
+						    void __user *arg,
+						    int subvol,
+						    u64 *transid)
 {
 	struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
 	struct btrfs_ioctl_vol_args *vol_args;
@@ -826,7 +844,7 @@  static noinline int btrfs_ioctl_snap_create(struct file *file,
 
 	if (subvol) {
 		ret = btrfs_mksubvol(&file->f_path, vol_args->name, namelen,
-				     NULL);
+				     NULL, transid);
 	} else {
 		struct inode *src_inode;
 		src_file = fget(vol_args->fd);
@@ -844,7 +862,8 @@  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,
+				     transid);
 		fput(src_file);
 	}
 out:
@@ -852,6 +871,48 @@  out:
 	return ret;
 }
 
+static noinline int btrfs_async_vol_args(void __user *arg,
+			     struct btrfs_ioctl_vol_args **vol_args,
+			     u64 __user **ptransid)
+{
+	struct btrfs_ioctl_async_vol_args *async_args;
+
+	async_args = memdup_user(arg, sizeof(*async_args));
+	if (IS_ERR(async_args))
+		return PTR_ERR(async_args);
+	*vol_args = async_args->args;
+	*ptransid = async_args->transid;
+	kfree(async_args);
+	return 0;
+}
+
+static noinline int btrfs_ioctl_snap_create(struct file *file,
+					    void __user *arg, int subvol,
+					    int async)
+{
+	struct btrfs_ioctl_vol_args *vol_args = arg;
+	u64 __user *ptransid = NULL;
+	u64 transid = 0;
+	int ret;
+
+	if (async) {
+		ret = btrfs_async_vol_args(arg, &vol_args, &ptransid);
+		if (ret < 0)
+			return ret;
+	}
+
+	ret = btrfs_ioctl_snap_create_transid(file, vol_args,
+					      subvol, &transid);
+
+	if (!ret && async && ptransid) {
+		if (copy_to_user(ptransid, &transid,
+				 sizeof(transid)))
+			return -EFAULT;
+	}
+
+	return ret;
+}
+
 /*
  * helper to check if the subvolume references other subvolumes
  */
@@ -2028,9 +2089,11 @@  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..8f28626 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -30,6 +30,11 @@  struct btrfs_ioctl_vol_args {
 	char name[BTRFS_PATH_NAME_MAX + 1];
 };
 
+struct btrfs_ioctl_async_vol_args {
+	struct btrfs_ioctl_vol_args *args;
+	__u64 *transid;
+};
+
 #define BTRFS_INO_LOOKUP_PATH_MAX 4080
 struct btrfs_ioctl_ino_lookup_args {
 	__u64 treeid;
@@ -180,4 +185,6 @@  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_async_vol_args)
 #endif