We need get write access for scrub, or we will modify the R/O fs.
Signed-off-by: Miao Xie <miaox@xxxxxxxxxxxxxx>
---
fs/btrfs/ioctl.c | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 5921bb9..a7afafa 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3103,10 +3103,11 @@ 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;
@@ -3115,12 +3116,21 @@ 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, sa->devid, sa->start, sa->end,
&sa->progress, sa->flags & BTRFS_SCRUB_READONLY);
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;
}
@@ -3802,7 +3812,7 @@ 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:
--
1.7.11.7
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