diff mbox series

[v2,1/5] 9p: Fix probe failed when modprobe 9pnet_virtio

Message ID 20221129160615.3343036-2-lizetao1@huawei.com (mailing list archive)
State Not Applicable
Delegated to: Netdev Maintainers
Headers show
Series Fix probe failed when modprobe modules | expand

Checks

Context Check Description
netdev/tree_selection success Guessed tree name to be net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers fail 1 blamed authors not CCed: mst@redhat.com; 1 maintainers not CCed: mst@redhat.com
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 7 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Li Zetao Nov. 29, 2022, 4:06 p.m. UTC
When doing the following test steps, an error was found:
  step 1: modprobe 9pnet_virtio succeeded
    # modprobe 9pnet_virtio      <-- OK

  step 2: fault injection in sysfs_create_file()
    # modprobe -r 9pnet_virtio   <-- OK
    # ...
      FAULT_INJECTION: forcing a failure.
      name failslab, interval 1, probability 0, space 0, times 0
      CPU: 0 PID: 3790 Comm: modprobe Tainted: G        W
      6.1.0-rc6-00285-g6a1e40c4b995-dirty #108
      Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
      Call Trace:
       <TASK>
       ...
       should_failslab+0xa/0x20
       ...
       sysfs_create_file_ns+0x130/0x1d0
       p9_virtio_probe+0x662/0xb30 [9pnet_virtio]
       virtio_dev_probe+0x608/0xae0
       ...
       </TASK>
      9pnet_virtio: probe of virtio3 failed with error -12

  step 3: modprobe 9pnet_virtio failed
    # modprobe 9pnet_virtio       <-- failed
      9pnet_virtio: probe of virtio3 failed with error -2

The root cause of the problem is that the virtqueues are not
stopped on the error handling path when sysfs_create_file()
fails in p9_virtio_probe(), resulting in an error "-ENOENT"
returned in the next modprobe call in setup_vq().

virtio_pci_modern_device uses virtqueues to send or
receive message, and "queue_enable" records whether the
queues are available. In vp_modern_find_vqs(), all queues
will be selected and activated, but once queues are enabled
there is no way to go back except reset.

Fix it by reset virtio device on error handling path. After
virtio_find_single_vq() succeeded, all virtqueues should be
stopped on error handling path.

Fixes: ea52bf8eda98 ("9p/trans_virtio: reset virtio device on remove")
Signed-off-by: Li Zetao <lizetao1@huawei.com>
Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com>
---
v1 -> v2: modify the description error of the test case in step 3 and
modify the fixes tag information.

 net/9p/trans_virtio.c | 1 +
 1 file changed, 1 insertion(+)
diff mbox series

Patch

diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index e757f0601304..39933187284b 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -668,6 +668,7 @@  static int p9_virtio_probe(struct virtio_device *vdev)
 out_free_tag:
 	kfree(tag);
 out_free_vq:
+	virtio_reset_device(vdev);
 	vdev->config->del_vqs(vdev);
 out_free_chan:
 	kfree(chan);