From a874a63e1389c1daabd5abe4e4faaf9d63daf474 Mon Sep 17 00:00:00 2001 From: Liu Bo Date: Fri, 29 Jun 2012 03:58:46 -0600 Subject: [PATCH] Btrfs: check write access to mount earlier while creating snapshots Move check of write access to mount into upper functions so that we can use mnt_want_write_file instead, which is faster than mnt_want_write. Signed-off-by: Liu Bo --- fs/btrfs/ioctl.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 3a3f916d7c0..c1f4975648e 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -652,13 +652,9 @@ static noinline int btrfs_mksubvol(struct path *parent, if (dentry->d_inode) goto out_dput; - error = mnt_want_write(parent->mnt); - if (error) - goto out_dput; - error = btrfs_may_create(dir, dentry); if (error) - goto out_drop_write; + goto out_dput; down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem); @@ -676,8 +672,6 @@ static noinline int btrfs_mksubvol(struct path *parent, fsnotify_mkdir(dir, dentry); out_up_read: up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem); -out_drop_write: - mnt_drop_write(parent->mnt); out_dput: dput(dentry); out_unlock: @@ -1395,16 +1389,20 @@ static noinline int btrfs_ioctl_snap_create_transid(struct file *file, if (root->fs_info->sb->s_flags & MS_RDONLY) return -EROFS; + ret = mnt_want_write_file(file); + if (ret) + goto out; + namelen = strlen(name); if (strchr(name, '/')) { ret = -EINVAL; - goto out; + goto out_drop_write; } if (name[0] == '.' && (namelen == 1 || (name[1] == '.' && namelen == 2))) { ret = -EEXIST; - goto out; + goto out_drop_write; } if (subvol) { @@ -1415,7 +1413,7 @@ static noinline int btrfs_ioctl_snap_create_transid(struct file *file, src_file = fget(fd); if (!src_file) { ret = -EINVAL; - goto out; + goto out_drop_write; } src_inode = src_file->f_path.dentry->d_inode; @@ -1424,13 +1422,15 @@ static noinline int btrfs_ioctl_snap_create_transid(struct file *file, "another FS\n"); ret = -EINVAL; fput(src_file); - goto out; + goto out_drop_write; } ret = btrfs_mksubvol(&file->f_path, name, namelen, BTRFS_I(src_inode)->root, transid, readonly); fput(src_file); } +out_drop_write: + mnt_drop_write_file(file); out: return ret; } -- 2.20.1