diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index ee36009f8aa1..12b18c01b911 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -3127,10 +3127,11 @@ static noinline long btrfs_ioctl_wait_sync(struct btrfs_root *root, return btrfs_wait_for_commit(root, transid); } -static long btrfs_ioctl_scrub(struct btrfs_root *root, void __user *arg) +static long btrfs_ioctl_scrub(struct file *file, void __user *arg) { - int ret; + struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root; struct btrfs_ioctl_scrub_args *sa; + int ret; if (!capable(CAP_SYS_ADMIN)) return -EPERM; @@ -3139,6 +3140,12 @@ static long btrfs_ioctl_scrub(struct btrfs_root *root, void __user *arg) if (IS_ERR(sa)) return PTR_ERR(sa); + if (!(sa->flags & BTRFS_SCRUB_READONLY)) { + ret = mnt_want_write_file(file); + if (ret) + goto out; + } + ret = btrfs_scrub_dev(root->fs_info, sa->devid, sa->start, sa->end, &sa->progress, sa->flags & BTRFS_SCRUB_READONLY, 0); @@ -3146,6 +3153,9 @@ static long btrfs_ioctl_scrub(struct btrfs_root *root, void __user *arg) if (copy_to_user(arg, sa, sizeof(*sa))) ret = -EFAULT; + if (!(sa->flags & BTRFS_SCRUB_READONLY)) + mnt_drop_write_file(file); +out: kfree(sa); return ret; } @@ -3879,7 +3889,7 @@ long btrfs_ioctl(struct file *file, unsigned int case BTRFS_IOC_WAIT_SYNC: return btrfs_ioctl_wait_sync(root, argp); case BTRFS_IOC_SCRUB: - return btrfs_ioctl_scrub(root, argp); + return btrfs_ioctl_scrub(file, argp); case BTRFS_IOC_SCRUB_CANCEL: return btrfs_ioctl_scrub_cancel(root, argp); case BTRFS_IOC_SCRUB_PROGRESS: