From b8e95489bf0ddf767e4bd38f537e0adad16ee830 Mon Sep 17 00:00:00 2001 From: Miao Xie Date: Mon, 26 Nov 2012 08:48:01 +0000 Subject: [PATCH] Btrfs: get write access for scrub We need get write access for scrub, or we will modify the R/O fs. Signed-off-by: Miao Xie Signed-off-by: Chris Mason --- 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 ee36009..12b18c0 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: -- 2.7.4