When mount is triggered for an already mounted share (using auto negotiation), it displays "mount.nfs: Protocol not supported" or "mount.nfs: access denied by server while mounting" instead of EBUSY. This easily causes confusion if the mount was not tried verbose : [root@rsable ~]# mount 127.0.0.1:/export /mnt mount.nfs: Protocol not supported [root@rsable ~]# mount -v 127.0.0.1:/export /mnt mount.nfs: timeout set for Mon Apr 5 16:03:53 2021 mount.nfs: trying text-based options 'vers=4.2,addr=127.0.0.1,clientaddr=127.0.0.1' mount.nfs: mount(2): Protocol not supported mount.nfs: trying text-based options 'vers=4,minorversion=1,addr=127.0.0.1,clientaddr=127.0.0.1' mount.nfs: mount(2): Protocol not supported mount.nfs: trying text-based options 'vers=4,addr=127.0.0.1,clientaddr=127.0.0.1' mount.nfs: mount(2): Protocol not supported mount.nfs: trying text-based options 'addr=127.0.0.1' mount.nfs: prog 100003, trying vers=3, prot=6 mount.nfs: trying 127.0.0.1 prog 100003 vers 3 prot TCP port 2049 mount.nfs: prog 100005, trying vers=3, prot=17 mount.nfs: trying 127.0.0.1 prog 100005 vers 3 prot UDP port 20048 mount.nfs: mount(2): Device or resource busy << actual error mount.nfs: Protocol not supported [root@rsable ~]# mount rsable76server:/testshare /mnt mount.nfs: access denied by server while mounting rsable76server:/testshare [root@rsable ~]# mount rsable76server:/testshare /mnt -v mount.nfs: timeout set for Mon Jan 17 13:36:16 2022 mount.nfs: trying text-based options 'vers=4.1,addr=192.168.122.58,clientaddr=192.168.122.82' mount.nfs: mount(2): Permission denied mount.nfs: trying text-based options 'vers=4.0,addr=192.168.122.58,clientaddr=192.168.122.82' mount.nfs: mount(2): Permission denied mount.nfs: trying text-based options 'addr=192.168.122.58' mount.nfs: prog 100003, trying vers=3, prot=6 mount.nfs: trying 192.168.122.58 prog 100003 vers 3 prot TCP port 2049 mount.nfs: prog 100005, trying vers=3, prot=17 mount.nfs: trying 192.168.122.58 prog 100005 vers 3 prot UDP port 20048 mount.nfs: mount(2): Device or resource busy << actual error mount.nfs: access denied by server while mounting rsable76server:/testshare Signed-off-by: Rohan Sable <rsable@xxxxxxxxxx> Signed-off-by: Yongcheng Yang <yoyang@xxxxxxxxxx> --- utils/mount/stropts.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/utils/mount/stropts.c b/utils/mount/stropts.c index 3c4e218a..573df6ee 100644 --- a/utils/mount/stropts.c +++ b/utils/mount/stropts.c @@ -973,7 +973,9 @@ fall_back: if ((result = nfs_try_mount_v3v2(mi, FALSE))) return result; - errno = olderrno; + if (errno != EBUSY || errno != EACCES) + errno = olderrno; + return result; } -- 2.34.1
