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authorDan Williams <dan.j.williams@intel.com>2010-05-12 08:25:37 +1000
committerNeilBrown <neilb@suse.de>2010-05-12 08:25:37 +1000
commite2218350465e7e0931676b4849b594c978437bce (patch)
tree395398081c277c533d28edd70d08a9394e7d8597 /drivers/md/md.c
parent627a2d3c29427637f4c5d31ccc7fcbd8d312cd71 (diff)
md: set mddev readonly flag on blkdev BLKROSET ioctl
When the user sets the block device to readwrite then the mddev should follow suit. Otherwise, the BUG_ON in md_write_start() will be set to trigger. The reverse direction, setting mddev->ro to match a set readonly request, can be ignored because the blkdev level readonly flag precludes the need to have mddev->ro set correctly. Nevermind the fact that setting mddev->ro to 1 may fail if the array is in use. Cc: <stable@kernel.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
Diffstat (limited to 'drivers/md/md.c')
-rw-r--r--drivers/md/md.c29
1 files changed, 29 insertions, 0 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c
index a20a71e5efd..08f665178c3 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -5489,6 +5489,7 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode,
int err = 0;
void __user *argp = (void __user *)arg;
mddev_t *mddev = NULL;
+ int ro;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
@@ -5624,6 +5625,34 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode,
err = do_md_stop(mddev, 1, 1);
goto done_unlock;
+ case BLKROSET:
+ if (get_user(ro, (int __user *)(arg))) {
+ err = -EFAULT;
+ goto done_unlock;
+ }
+ err = -EINVAL;
+
+ /* if the bdev is going readonly the value of mddev->ro
+ * does not matter, no writes are coming
+ */
+ if (ro)
+ goto done_unlock;
+
+ /* are we are already prepared for writes? */
+ if (mddev->ro != 1)
+ goto done_unlock;
+
+ /* transitioning to readauto need only happen for
+ * arrays that call md_write_start
+ */
+ if (mddev->pers) {
+ err = restart_array(mddev);
+ if (err == 0) {
+ mddev->ro = 2;
+ set_disk_ro(mddev->gendisk, 0);
+ }
+ }
+ goto done_unlock;
}
/*