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authorIlya Dryomov2019-11-12 19:50:55 +0100
committerIlya Dryomov2019-11-25 11:44:03 +0100
commitc1b6205730ef009868fbb68cf4755b20055fcc6c (patch)
tree4e939119a3c73f76a5fb99af5cce6511d9fa0b8b /drivers/block/rbd.c
parentb948ad78971fb2c6ed6b53b0edbdd720cfe08d9f (diff)
rbd: disallow read-write partitions on images mapped read-only
If an image is mapped read-only, don't allow setting its partition(s) to read-write via BLKROSET: with the previous patch all writes to such images are failed anyway. If an image is mapped read-write, its partition(s) can be set to read-only (and back to read-write) as before. Note that at the rbd level the image will remain writeable: anything sent down by the block layer will be executed, including any write from internal kernel users. Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Reviewed-by: Jason Dillaman <dillaman@redhat.com> Reviewed-by: Dongsheng Yang <dongsheng.yang@easystack.cn>
Diffstat (limited to 'drivers/block/rbd.c')
-rw-r--r--drivers/block/rbd.c13
1 files changed, 10 insertions, 3 deletions
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 02cd2a7df6dd..978e4d846f64 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -706,9 +706,16 @@ static int rbd_ioctl_set_ro(struct rbd_device *rbd_dev, unsigned long arg)
if (get_user(ro, (int __user *)arg))
return -EFAULT;
- /* Snapshots can't be marked read-write */
- if (rbd_is_snap(rbd_dev) && !ro)
- return -EROFS;
+ /*
+ * Both images mapped read-only and snapshots can't be marked
+ * read-write.
+ */
+ if (!ro) {
+ if (rbd_is_ro(rbd_dev))
+ return -EROFS;
+
+ rbd_assert(!rbd_is_snap(rbd_dev));
+ }
/* Let blkdev_roset() handle it */
return -ENOTTY;