[PATCH 28/78] md: implement ->set_read_only to hook into BLKROSET processing

Christoph Hellwig
2020-11-16T15:03:12Z

Implement the ->set_read_only method instead of parsing the actual
ioctl command.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/md/md.c | 62 ++++++++++++++++++++++++-------------------------
1 file changed, 31 insertions(+), 31 deletions(-)

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 32e375d50fee17..fa31b71a72a35d 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -7477,7 +7477,6 @@ static inline bool md_ioctl_valid(unsigned int cmd)
{
switch (cmd) {
case ADD_NEW_DISK:
- case BLKROSET:
case GET_ARRAY_INFO:
case GET_BITMAP_FILE:
case GET_DISK_INFO:
@@ -7504,7 +7503,6 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode,
int err = 0;
void __user *argp = (void __user *)arg;
struct mddev *mddev = NULL;
- int ro;
bool did_set_md_closing = false;

if (!md_ioctl_valid(cmd))
@@ -7684,35 +7682,6 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode,
goto unlock;
}
break;
-
- case BLKROSET:
- if (get_user(ro, (int __user *)(arg))) {
- err = -EFAULT;
- goto unlock;
- }
- err = -EINVAL;
-
- /* if the bdev is going readonly the value of mddev->ro
- * does not matter, no writes are coming
- */
- if (ro)
- goto unlock;
-
- /* are we are already prepared for writes? */
- if (mddev->ro != 1)
- goto 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 unlock;
}

/*
@@ -7806,6 +7775,36 @@ static int md_compat_ioctl(struct block_device *bdev, fmode_t mode,
}
#endif /* CONFIG_COMPAT */

+static int md_set_read_only(struct block_device *bdev, bool ro)
+{
+ struct mddev *mddev = bdev->bd_disk->private_data;
+ int err;
+
+ err = mddev_lock(mddev);
+ if (err)
+ return err;
+
+ if (!mddev->raid_disks && !mddev->external) {
+ err = -ENODEV;
+ goto out_unlock;
+ }
+
+ /*
+ * Transitioning to read-auto need only happen for arrays that call
+ * md_write_start and which are not ready for writes yet.
+ */
+ if (!ro && mddev->ro == 1 && mddev->pers) {
+ err = restart_array(mddev);
+ if (err)
+ goto out_unlock;
+ mddev->ro = 2;
+ }
+
+out_unlock:
+ mddev_unlock(mddev);
+ return err;
+}
+
static int md_open(struct block_device *bdev, fmode_t mode)
{
/*
@@ -7883,6 +7882,7 @@ const struct block_device_operations md_fops =
#endif
.getgeo = md_getgeo,
.check_events = md_check_events,
+ .set_read_only = md_set_read_only,
};

static int md_thread(void *arg)