diff options
| author | Liu Bo <liubo2009@cn.fujitsu.com> | 2012-05-11 18:11:26 +0800 |
|---|---|---|
| committer | Josef Bacik <josef@redhat.com> | 2012-05-30 10:23:35 -0400 |
| commit | 9ba1f6e44ed7a1fa52d3f292508bf921b5054172 (patch) | |
| tree | 2c20508be673a9ebce14d27efa6ee05a04695787 | |
| parent | d1ac6e41d5437385957fd708e285defd0b1a430c (diff) | |
Btrfs: do not do balance in readonly mode
In normal cases, we would not be allowed to do balance in RO mode.
However, when we're using a seeding device and adding another device to sprout,
things will change:
$ mkfs.btrfs /dev/sdb7
$ btrfstune -S 1 /dev/sdb7
$ mount /dev/sdb7 /mnt/btrfs -o ro
$ btrfs fi bal /mnt/btrfs -----------------------> fail.
$ btrfs dev add /dev/sdb8 /mnt/btrfs
$ btrfs fi bal /mnt/btrfs -----------------------> works!
It should not be designed as an exception, and we'd better add another check for
mnt flags.
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Reviewed-by: Josef Bacik <josef@redhat.com>
| -rw-r--r-- | fs/btrfs/ioctl.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 3d8ab27622c..15baf945630 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -3216,8 +3216,9 @@ void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock, } } -static long btrfs_ioctl_balance(struct btrfs_root *root, void __user *arg) +static long btrfs_ioctl_balance(struct file *file, void __user *arg) { + struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root; struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_ioctl_balance_args *bargs; struct btrfs_balance_control *bctl; @@ -3229,6 +3230,10 @@ static long btrfs_ioctl_balance(struct btrfs_root *root, void __user *arg) if (fs_info->sb->s_flags & MS_RDONLY) return -EROFS; + ret = mnt_want_write(file->f_path.mnt); + if (ret) + return ret; + mutex_lock(&fs_info->volume_mutex); mutex_lock(&fs_info->balance_mutex); @@ -3295,6 +3300,7 @@ out_bargs: out: mutex_unlock(&fs_info->balance_mutex); mutex_unlock(&fs_info->volume_mutex); + mnt_drop_write(file->f_path.mnt); return ret; } @@ -3390,7 +3396,7 @@ long btrfs_ioctl(struct file *file, unsigned int case BTRFS_IOC_DEV_INFO: return btrfs_ioctl_dev_info(root, argp); case BTRFS_IOC_BALANCE: - return btrfs_ioctl_balance(root, NULL); + return btrfs_ioctl_balance(file, NULL); case BTRFS_IOC_CLONE: return btrfs_ioctl_clone(file, arg, 0, 0, 0); case BTRFS_IOC_CLONE_RANGE: @@ -3423,7 +3429,7 @@ long btrfs_ioctl(struct file *file, unsigned int case BTRFS_IOC_SCRUB_PROGRESS: return btrfs_ioctl_scrub_progress(root, argp); case BTRFS_IOC_BALANCE_V2: - return btrfs_ioctl_balance(root, argp); + return btrfs_ioctl_balance(file, argp); case BTRFS_IOC_BALANCE_CTL: return btrfs_ioctl_balance_ctl(root, arg); case BTRFS_IOC_BALANCE_PROGRESS: |