Description of problem: Using mount to remount a mountpoint failed if the mountpoint is nfs with ipv6 address. Version-Release number of selected component (if applicable): util-linux-2.24-2.fc20.x86_64 How reproducible: 100% Steps to Reproduce: 1. add a entry in /etc/fstab like "[fe80::5054:ff:fe48:ca80%eth0]:/mnt /mnt nfs defaults 0 0" 2.reboot 3.remount the mountpoint /mnt using "mount -o remount,ro /mnt" Actual results: remount failed Expected results: remount succeed Additional info: Filesystem 1K-blocks Used Available Use% Mounted on /dev/mapper/fedora-root 8649736 3285568 4901732 41% / devtmpfs 952308 0 952308 0% /dev tmpfs 960236 0 960236 0% /dev/shm tmpfs 960236 604 959632 1% /run tmpfs 960236 0 960236 0% /sys/fs/cgroup tmpfs 960236 4 960232 1% /tmp /dev/vda1 487652 95988 361968 21% /boot [fe80::5054:ff:fe48:ca80%eth0]:/mnt 8649984 3589120 4598528 44% /mnt [root@localhost ~]# mount -o remount,ro /mnt [ 40.842524] BUG: unable to handle kernel NULL pointer dereference at 00000000000000d8 [ 40.843025] IP: [<ffffffff81546dcf>] dev_get_by_name_rcu+0x2f/0x90 [ 40.843025] PGD 0 [ 40.843025] Oops: 0000 [#1] SMP [ 40.843025] Modules linked in: nfsv4 dns_resolver nfs fscache nf_conntrack_netbios_ns nf_conntrack_broadcast ipt_MASQUERADE bnep bluetooth cfg80211 rfkill ip6t_REJECT xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw joydev i2c_piix4 i2c_core ppdev parport_pc parport virtio_balloon microcode serio_raw mperf nfsd auth_rpcgss nfs_acl lockd sunrpc virtio_blk virtio_net virtio_pci virtio_ring ata_generic virtio pata_acpi [ 40.843025] CPU: 1 PID: 1259 Comm: mount.nfs Not tainted 3.11.10-301.fc20.x86_64 #1 [ 40.843025] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 40.843025] task: ffff88007a981e80 ti: ffff88007bc1c000 task.ti: ffff88007bc1c000 [ 40.843025] RIP: 0010:[<ffffffff81546dcf>] [<ffffffff81546dcf>] dev_get_by_name_rcu+0x2f/0x90 [ 40.843025] RSP: 0018:ffff88007bc1dd30 EFLAGS: 00010a87 [ 40.843025] RAX: 00000000881b7465 RBX: 0000000000000000 RCX: 0000000000000020 [ 40.843025] RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000030687465 [ 40.843025] RBP: ffff88007bc1dd40 R08: 0000000000016e80 R09: ffff88007d001e00 [ 40.843025] R10: 0000000000000004 R11: ffff88007bc1dd10 R12: ffff88007a811a60 [ 40.843025] R13: ffff88007a3650f8 R14: 0000000000000000 R15: ffff88007a365100 [ 40.843025] FS: 00007f80252a18c0(0000) GS:ffff88007fd00000(0000) knlGS:0000000000000000 [ 40.843025] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 40.843025] CR2: 00000000000000d8 CR3: 000000007ab2f000 CR4: 00000000000006e0 [ 40.843025] Stack: [ 40.843025] ffff88007a811a60 ffff88007ac2b620 ffff88007bc1dd50 ffffffff81546e3e [ 40.843025] ffff88007bc1dda0 ffffffffa0056f1e ffff88007ac2b637 ffff88007ac2b637 [ 40.843025] 0000000000000000 ffff88007a365000 0000000000000000 0000000000000000 [ 40.843025] Call Trace: [ 40.843025] [<ffffffff81546e3e>] dev_get_by_name+0xe/0x20 [ 40.843025] [<ffffffffa0056f1e>] rpc_pton+0x10e/0x1d0 [sunrpc] [ 40.843025] [<ffffffffa0319218>] nfs_parse_mount_options+0x398/0xc70 [nfs] [ 40.843025] [<ffffffff8118ea67>] ? kmem_cache_alloc_trace+0x1d7/0x230 [ 40.843025] [<ffffffffa031bc27>] ? nfs_remount+0x67/0x350 [nfs] [ 40.843025] [<ffffffffa031bd2a>] nfs_remount+0x16a/0x350 [nfs] [ 40.843025] [<ffffffff811acb0a>] do_remount_sb+0x7a/0x1a0 [ 40.843025] [<ffffffff811c86a9>] do_mount+0x689/0xa20 [ 40.843025] [<ffffffff811c7ea6>] ? copy_mount_options+0x36/0x170 [ 40.843025] [<ffffffff811c8ac3>] SyS_mount+0x83/0xc0 [ 40.843025] [<ffffffff816533d9>] system_call_fastpath+0x16/0x1b [ 40.843025] Code: 00 55 48 89 e5 41 54 49 89 f4 be 10 00 00 00 53 48 89 fb 4c 89 e7 e8 c1 b3 db ff 4c 89 e7 89 c6 e8 97 cb c6 ff 69 c0 01 00 37 9e <48> 8b 93 d8 00 00 00 31 db c1 e8 18 48 8d 04 c2 48 8b 00 48 8d [ 40.843025] RIP [<ffffffff81546dcf>] dev_get_by_name_rcu+0x2f/0x90 [ 40.843025] RSP <ffff88007bc1dd30> [ 40.843025] CR2: 00000000000000d8 [ 40.891754] ---[ end trace 4bc36db59be31d9a ]--- [root@localhost ~]# cat /etc/fstab # # /etc/fstab # Created by anaconda on Wed May 21 03:34:42 2014 # # Accessible filesystems, by reference, are maintained under '/dev/disk' # See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info # /dev/mapper/fedora-root / ext4 defaults 1 1 UUID=e271aea5-ed08-4c3d-9732-07daa6f00f22 /boot ext4 defaults 1 2 /dev/mapper/fedora-swap swap swap defaults 0 0 [fe80::5054:ff:fe48:ca80%eth0]:/mnt /mnt nfs defaults 0 0
Can you recreate this with the latest F20 kernel update (3.14.4)? 3.11.10 is the GA kernel for F20 and is rather old at this point.
(In reply to Josh Boyer from comment #1) > Can you recreate this with the latest F20 kernel update (3.14.4)? 3.11.10 > is the GA kernel for F20 and is rather old at this point. Hi Josh Boyer, remount still failed with the latest kernle 3.14.4-200.fc20.x86_64 [ 42.537784] BUG: unable to handle kernel NULL pointer dereference at 00000000000000d8 [ 42.538027] IP: [<ffffffff815e243f>] dev_get_by_name_rcu+0x2f/0x90 [ 42.538027] PGD 0 [ 42.538027] Oops: 0000 [#1] SMP [ 42.538027] Modules linked in: rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache bnep bluetooth 6lowpan_iphc nf_conntrack_netbios_ns nf_conntrack_broadcast ipt_MASQUERADE cfg80211 rfkill ip6t_REJECT xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw ppdev i2c_piix4 microcode parport_pc virtio_balloon parport pvpanic serio_raw i2c_core nfsd auth_rpcgss nfs_acl lockd sunrpc virtio_blk virtio_net virtio_pci virtio_ring virtio ata_generic pata_acpi [ 42.538027] CPU: 1 PID: 1271 Comm: mount.nfs Not tainted 3.14.4-200.fc20.x86_64 #1 [ 42.538027] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 42.538027] task: ffff88003731cc00 ti: ffff88007a584000 task.ti: ffff88007a584000 [ 42.538027] RIP: 0010:[<ffffffff815e243f>] [<ffffffff815e243f>] dev_get_by_name_rcu+0x2f/0x90 [ 42.538027] RSP: 0018:ffff88007a585d08 EFLAGS: 00010a87 [ 42.538027] RAX: 00000000881b7465 RBX: 0000000000000000 RCX: 0000000000000020 [ 42.538027] RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000030687465 [ 42.538027] RBP: ffff88007a585d18 R08: 0000000000017380 R09: ffff88007d001e00 [ 42.538027] R10: 0000000000000004 R11: ffff88007a585ce8 R12: ffff88007a772e00 [ 42.538027] R13: ffff88007b27df28 R14: 0000000000000000 R15: ffff88007b27df30 [ 42.538027] FS: 00007fa15a4b88c0(0000) GS:ffff88007fd00000(0000) knlGS:0000000000000000 [ 42.538027] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 42.538027] CR2: 00000000000000d8 CR3: 000000007c3db000 CR4: 00000000000006e0 [ 42.538027] Stack: [ 42.538027] ffff88007a772e00 ffff8800370341c0 ffff88007a585d28 ffffffff815e24ae [ 42.538027] ffff88007a585d80 ffffffffa004de32 ffff8800370341d7 ffff8800370341d7 [ 42.538027] 0000000000000000 00000000320eb197 ffff88007b27de00 0000000000000000 [ 42.538027] Call Trace: [ 42.538027] [<ffffffff815e24ae>] dev_get_by_name+0xe/0x20 [ 42.538027] [<ffffffffa004de32>] rpc_pton+0x132/0x1f0 [sunrpc] [ 42.538027] [<ffffffffa03350e8>] nfs_parse_mount_options+0x3a8/0xc90 [nfs] [ 42.538027] [<ffffffff811ccd06>] ? kmem_cache_alloc_trace+0x1d6/0x200 [ 42.538027] [<ffffffffa0337e03>] nfs_remount+0x1d3/0x3f0 [nfs] [ 42.538027] [<ffffffff811ed34a>] do_remount_sb+0x7a/0x1a0 [ 42.538027] [<ffffffff8120b221>] do_mount+0x6c1/0xae0 [ 42.538027] [<ffffffff811796a4>] ? __get_free_pages+0x14/0x50 [ 42.538027] [<ffffffff8120b976>] SyS_mount+0x96/0xf0 [ 42.538027] [<ffffffff816ff569>] system_call_fastpath+0x16/0x1b [ 42.538027] Code: 00 55 48 89 e5 41 54 49 89 f4 be 10 00 00 00 53 48 89 fb 4c 89 e7 e8 11 98 d7 ff 4c 89 e7 89 c6 e8 d7 24 c1 ff 69 c0 01 00 37 9e <48> 8b 93 d8 00 00 00 31 db c1 e8 18 48 8d 04 c2 48 8b 00 48 8d [ 42.538027] RIP [<ffffffff815e243f>] dev_get_by_name_rcu+0x2f/0x90 [ 42.538027] RSP <ffff88007a585d08> [ 42.538027] CR2: 00000000000000d8 [ 42.565834] ---[ end trace 163129b3911cbefc ]--- Thanks zzou
The bug is that ->net is not popoulated when remounting. This fixes the problem for me: diff --git a/fs/nfs/super.c b/fs/nfs/super.c index 2cb5694..104ef01 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -2248,6 +2248,7 @@ nfs_remount(struct super_block *sb, int *flags, char *raw_data) data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen; data->version = nfsvers; data->minorversion = nfss->nfs_client->cl_minorversion; + data->net = current->nsproxy->net_ns; memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr, data->nfs_server.addrlen); As for reproducer, it is enough to: mount -t nfs '[fe80::5054:ff:fe10:223a%eth0]':/mnt/export /mnt/tmp mount -t nfs -o remount,ro '[fe80::5054:ff:fe10:223a%eth0]':/mnt/export /mnt/tmp
Patch sent upstream: http://www.mail-archive.com/linux-kernel@vger.kernel.org/msg660865.html
Patch got committed with id a914722f333b3359d2f4f12919380a334176bb89 . Do I have to do anything else w.r.t. fedora?
(In reply to Mateusz Guzik from comment #5) > Patch got committed with id a914722f333b3359d2f4f12919380a334176bb89 . > > Do I have to do anything else w.r.t. fedora? No, it's CC'd to stable and we'll either pick it up when it hits 3.14.y or 3.15.y, if not before then. Thanks!
Picked this up early. Thanks again.
kernel-3.14.7-200.fc20 has been submitted as an update for Fedora 20. https://admin.fedoraproject.org/updates/kernel-3.14.7-200.fc20
kernel-3.14.7-100.fc19 has been submitted as an update for Fedora 19. https://admin.fedoraproject.org/updates/kernel-3.14.7-100.fc19
Package kernel-3.14.7-200.fc20: * should fix your issue, * was pushed to the Fedora 20 testing repository, * should be available at your local mirror within two days. Update it with: # su -c 'yum update --enablerepo=updates-testing kernel-3.14.7-200.fc20' as soon as you are able to, then reboot. Please go to the following url: https://admin.fedoraproject.org/updates/FEDORA-2014-7313/kernel-3.14.7-200.fc20 then log in and leave karma (feedback).
kernel-3.14.7-200.fc20 has been pushed to the Fedora 20 stable repository. If problems still persist, please make note of it in this bug report.
kernel-3.14.7-100.fc19 has been pushed to the Fedora 19 stable repository. If problems still persist, please make note of it in this bug report.