diff options
| author | Benjamin Coddington <bcodding@redhat.com> | 2024-11-22 10:11:11 -0500 |
|---|---|---|
| committer | Trond Myklebust <trond.myklebust@hammerspace.com> | 2024-11-28 12:55:32 -0500 |
| commit | 3a4ce14d9a6b868e0787e4582420b721c04ee41e (patch) | |
| tree | 4f5804162623b019fa28da40aff337a433b18b24 | |
| parent | 3f23f96528e8fcf8619895c4c916c52653892ec1 (diff) | |
nfs/blocklayout: Don't attempt unregister for invalid block device
Since commit d869da91cccb ("nfs/blocklayout: Fix premature PR key
unregistration") an unmount of a pNFS SCSI layout-enabled NFS may
dereference a NULL block_device in:
bl_unregister_scsi+0x16/0xe0 [blocklayoutdriver]
bl_free_device+0x70/0x80 [blocklayoutdriver]
bl_free_deviceid_node+0x12/0x30 [blocklayoutdriver]
nfs4_put_deviceid_node+0x60/0xc0 [nfsv4]
nfs4_deviceid_purge_client+0x132/0x190 [nfsv4]
unset_pnfs_layoutdriver+0x59/0x60 [nfsv4]
nfs4_destroy_server+0x36/0x70 [nfsv4]
nfs_free_server+0x23/0xe0 [nfs]
deactivate_locked_super+0x30/0xb0
cleanup_mnt+0xba/0x150
task_work_run+0x59/0x90
syscall_exit_to_user_mode+0x217/0x220
do_syscall_64+0x8e/0x160
This happens because even though we were able to create the
nfs4_deviceid_node, the lookup for the device was unable to attach the
block device to the pnfs_block_dev.
If we never found a block device to register, we can avoid this case with
the PNFS_BDEV_REGISTERED flag. Move the deref behind the test for the
flag.
Fixes: d869da91cccb ("nfs/blocklayout: Fix premature PR key unregistration")
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
| -rw-r--r-- | fs/nfs/blocklayout/dev.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/fs/nfs/blocklayout/dev.c b/fs/nfs/blocklayout/dev.c index 6252f4447945..cab8809f0e0f 100644 --- a/fs/nfs/blocklayout/dev.c +++ b/fs/nfs/blocklayout/dev.c @@ -20,9 +20,6 @@ static void bl_unregister_scsi(struct pnfs_block_dev *dev) const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops; int status; - if (!test_and_clear_bit(PNFS_BDEV_REGISTERED, &dev->flags)) - return; - status = ops->pr_register(bdev, dev->pr_key, 0, false); if (status) trace_bl_pr_key_unreg_err(bdev, dev->pr_key, status); @@ -58,7 +55,8 @@ static void bl_unregister_dev(struct pnfs_block_dev *dev) return; } - if (dev->type == PNFS_BLOCK_VOLUME_SCSI) + if (dev->type == PNFS_BLOCK_VOLUME_SCSI && + test_and_clear_bit(PNFS_BDEV_REGISTERED, &dev->flags)) bl_unregister_scsi(dev); } |