diff mbox

[2/2] Fix protocol minor version fall-back

Message ID 20151217015634.19978.65001.stgit@noble (mailing list archive)
State New, archived
Headers show

Commit Message

NeilBrown Dec. 17, 2015, 1:56 a.m. UTC
mount.nfs currently expects mount(2) to fail with EPROTONOSUPPORT if
the kernel doesn't understand the requested NFS version.

Unfortunately if the requested minor is not known to the kernel
it returns -EINVAL.
In kernels since 3.11 this can happen in nfs4_alloc_client(), if
compiled without NFS_V4_2.

More generally it can happen in in nfs_validate_text_mount_data()
when nfs_parse_mount_options() returns 0 because nfs_parse_version_string()
didn't recognise the version.

EPROTONOSUPPORT is only returned if NFSv4 support is completely compiled out.

So nfs_autonegotiate needs to check for EINVAL as well as EPROTONOSUPPORT.

URL: https://bugzilla.opensuse.org/show_bug.cgi?id=959211
Reported-by: Takashi Iwai <tiwai@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>
---
 utils/mount/stropts.c |    3 +++
 1 file changed, 3 insertions(+)



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diff mbox

Patch

diff --git a/utils/mount/stropts.c b/utils/mount/stropts.c
index c8f5a6d223e7..86829a902bfd 100644
--- a/utils/mount/stropts.c
+++ b/utils/mount/stropts.c
@@ -841,6 +841,9 @@  check_result:
 	case EPROTONOSUPPORT:
 		/* A clear indication that the server or our
 		 * client does not support NFS version 4 and minor */
+	case EINVAL:
+		/* A less clear indication that our client
+		 * does not support NFSv4 minor version. */
 		if (mi->version.v_mode == V_GENERAL &&
 			mi->version.minor == 0)
 				return result;