From fa3306595071ae03e181c2336d0dcd8f5e3cf9b0 Mon Sep 17 00:00:00 2001 From: Omar Sandoval Date: Mon, 18 May 2015 02:16:28 -0700 Subject: [PATCH] Btrfs: clean up error handling in mount_subvol() In preparation for new functionality in mount_subvol(), give it ownership of subvol_name and tidy up the error paths. Reviewed-by: David Sterba Signed-off-by: Omar Sandoval Signed-off-by: Chris Mason --- fs/btrfs/super.c | 61 ++++++++++++++++++++++++++---------------------- 1 file changed, 33 insertions(+), 28 deletions(-) diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 1c57c0d0dc41..dd89dd353c4a 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -1171,55 +1171,61 @@ static struct dentry *mount_subvol(const char *subvol_name, int flags, const char *device_name, char *data) { struct dentry *root; - struct vfsmount *mnt; + struct vfsmount *mnt = NULL; char *newargs; + int ret; newargs = setup_root_args(data); - if (!newargs) - return ERR_PTR(-ENOMEM); - mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name, - newargs); + if (!newargs) { + root = ERR_PTR(-ENOMEM); + goto out; + } - if (PTR_RET(mnt) == -EBUSY) { + mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name, newargs); + if (PTR_ERR_OR_ZERO(mnt) == -EBUSY) { if (flags & MS_RDONLY) { - mnt = vfs_kern_mount(&btrfs_fs_type, flags & ~MS_RDONLY, device_name, - newargs); + mnt = vfs_kern_mount(&btrfs_fs_type, flags & ~MS_RDONLY, + device_name, newargs); } else { - int r; - mnt = vfs_kern_mount(&btrfs_fs_type, flags | MS_RDONLY, device_name, - newargs); + mnt = vfs_kern_mount(&btrfs_fs_type, flags | MS_RDONLY, + device_name, newargs); if (IS_ERR(mnt)) { - kfree(newargs); - return ERR_CAST(mnt); + root = ERR_CAST(mnt); + mnt = NULL; + goto out; } down_write(&mnt->mnt_sb->s_umount); - r = btrfs_remount(mnt->mnt_sb, &flags, NULL); + ret = btrfs_remount(mnt->mnt_sb, &flags, NULL); up_write(&mnt->mnt_sb->s_umount); - if (r < 0) { - /* FIXME: release vfsmount mnt ??*/ - kfree(newargs); - return ERR_PTR(r); + if (ret < 0) { + root = ERR_PTR(ret); + goto out; } } } - - kfree(newargs); - - if (IS_ERR(mnt)) - return ERR_CAST(mnt); + if (IS_ERR(mnt)) { + root = ERR_CAST(mnt); + mnt = NULL; + goto out; + } root = mount_subtree(mnt, subvol_name); + /* mount_subtree() drops our reference on the vfsmount. */ + mnt = NULL; if (!IS_ERR(root) && !is_subvolume_inode(d_inode(root))) { struct super_block *s = root->d_sb; dput(root); root = ERR_PTR(-EINVAL); deactivate_locked_super(s); - printk(KERN_ERR "BTRFS: '%s' is not a valid subvolume\n", - subvol_name); + pr_err("BTRFS: '%s' is not a valid subvolume\n", subvol_name); } +out: + mntput(mnt); + kfree(newargs); + kfree(subvol_name); return root; } @@ -1305,9 +1311,8 @@ static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags, } if (subvol_name) { - root = mount_subvol(subvol_name, flags, device_name, data); - kfree(subvol_name); - return root; + /* mount_subvol() will free subvol_name. */ + return mount_subvol(subvol_name, flags, device_name, data); } security_init_mnt_opts(&new_sec_opts); -- 2.30.2