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| author |   Ilya Dryomov <idryomov@gmail.com> | 2019-11-12 19:50:55 +0100 |
|---|---|---|
| committer | Ilya Dryomov <idryomov@gmail.com> | 2019-11-25 11:44:03 +0100 |
| commit | c1b6205730ef009868fbb68cf4755b20055fcc6c (patch) | |
| tree | 4e939119a3c73f76a5fb99af5cce6511d9fa0b8b /drivers/block | |
| parent | rbd: treat images mapped read-only seriously (diff) | |
| download | linux-dev-c1b6205730ef009868fbb68cf4755b20055fcc6c.tar.xz linux-dev-c1b6205730ef009868fbb68cf4755b20055fcc6c.zip | |
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')
| -rw-r--r-- | drivers/block/rbd.c | 13 |
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; |