Hi Jongman, Is the panic on your client or server? I don't see how the patch your bisect led you to could cause the problem, since all it does is expand the minor version array on the server. Your client doesn't have NFSD enabled, so this code shouldn't even be affecting it. A few questions: what is your /etc/exports on the server? What version of NFS are you using for nfsroot? Thanks! Anna On Wed, Sep 25, 2013 at 1:19 AM, Jongman Heo <jongman.heo@xxxxxxxxxxx> wrote: > > Hi all, > > My embedded development box fails to NFS-boot with NFS server which uses recent kernel. > > Using git bisect, I found it is caused by commit 4bdc33ed ("NFSDv4.2: Add NFS v4.2 support to the NFS server"). > > > 1. dmesg (NFS boot failure case) > > ... > [ 2.040893] ADDRCONF(NETDEV_UP): eth0: link is not ready > [ 2.046207] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX > [ 2.053570] ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready > [ 3.055023] IP-Config: Guessing netmask 255.255.0.0 > [ 3.059979] IP-Config: Gateway not on directly connected network. > [ 3.066330] Looking up port of RPC 100003/2 on 165.213.88.249 > [ 3.074001] Looking up port of RPC 100005/1 on 165.213.88.249 > [ 3.122878] VFS: Unable to mount root fs via NFS, trying floppy. > [ 3.129134] VFS: Cannot open root device "nfs" or unknown-block(2,0) > [ 3.135478] Please append a correct "root=" boot option; here are the available partitions: > [ 3.143831] 1f00 3072 mtdblock0 (driver?) > [ 3.148798] 1f01 64 mtdblock1 (driver?) > [ 3.153758] 1f02 64 mtdblock2 (driver?) > [ 3.158719] 1f03 64 mtdblock3 (driver?) > [ 3.163682] 1f04 64 mtdblock4 (driver?) > [ 3.168644] 1f05 64 mtdblock5 (driver?) > [ 3.173607] 1f06 64 mtdblock6 (driver?) > [ 3.178568] 0800 488386584 sda driver: sd > [ 3.183099] 0801 506016 sda1 > [ 3.186927] 0802 4008217 sda2 > [ 3.190755] 0803 483869767 sda3 > [ 3.194584] b300 1880064 mmcblk0 driver: mmcblk > [ 3.199802] b301 4096 mmcblk0p1 > [ 3.204063] b302 102400 mmcblk0p2 > [ 3.208330] b303 4096 mmcblk0p3 > [ 3.212594] b304 1 mmcblk0p4 > [ 3.216855] b305 2048 mmcblk0p5 > [ 3.221116] b306 2048 mmcblk0p6 > [ 3.225382] b307 2048 mmcblk0p7 > [ 3.229644] b308 4096 mmcblk0p8 > [ 3.233906] b309 12288 mmcblk0p9 > [ 3.238176] b30a 16384 mmcblk0p10 > [ 3.242524] b30b 142336 mmcblk0p11 > [ 3.246869] b30c 1572864 mmcblk0p12 > [ 3.251219] b320 12288 mmcblk0gp1 (driver?) > [ 3.256272] b310 12288 mmcblk0gp0 (driver?) > [ 3.261320] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(2,0) > [ 3.269566] Pid: 1, comm: swapper Not tainted 2.6.35 #1 > [ 3.274776] Call Trace: > [ 3.277232] [<80d0db5b>] ? printk+0x1e/0x20 > [ 3.281492] [<80d0dad1>] panic+0x65/0xd1 > [ 3.285495] [<80eb9ce3>] mount_block_root+0x125/0x1be > [ 3.290631] [<809d1f6d>] ? sys_mknod+0x2d/0x30 > [ 3.295156] [<80eb9f6d>] mount_root+0xd0/0xf2 > [ 3.299591] [<80eba0d9>] prepare_namespace+0x14a/0x184 > [ 3.304803] [<809c44f6>] ? sys_access+0x26/0x30 > [ 3.309411] [<80eb9a4e>] kernel_init+0x25e/0x26e > [ 3.314105] [<80eb97f0>] ? kernel_init+0x0/0x26e > [ 3.318800] [<80903242>] kernel_thread_helper+0x6/0x10 > > > 2. Client (my embedded box) configuration > It's kernel 2.6.35 based, and has following NFS kernel configs. > > # grep NFS .config > CONFIG_NFS_FS=y > CONFIG_NFS_V3=y > CONFIG_NFS_V3_ACL=y > CONFIG_NFS_V4=y > # CONFIG_NFS_V4_1 is not set > CONFIG_ROOT_NFS=y > # CONFIG_NFSD is not set > CONFIG_NFS_ACL_SUPPORT=y > CONFIG_NFS_COMMON=y > > > 3. Server (NFSD) configuration > Fedora 19 + latest linus git kernel 3.12.0-rc2+ (commit 22356f44, mm: Place preemption point in do_mlockall() loop) > > > 4. workaround > > Reverting the commit 4bdc33ed resolves my issue, NFS boot is working then. > I've done git bisect, but lost the resulting bisect log due to sudden power loss :(. > > Best regards, > Jongman Heo -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html