FYI, we noticed the below changes on

git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
commit 5dc5218840e1268de639150a851978bb19c341df ("fs: create proper filename objects using getname_kernel()")

[   16.813397] 010f           65536 ram15  (driver?)
[   16.815041] fc00       268435456 vda  driver: virtio_blk
[   16.816777] fc10       268435456 vdb  driver: virtio_blk
[   16.818544] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(1,0)
[   16.819520] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.19.0-rc5-next-20150120-g5d0eebb #799
[   16.819520] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014
[   16.819520]  ffff8800076a0000 ffff880006f47db8 ffffffff81b7a16b ffffffff810cf061
[   16.819520]  ffffffff81fd6ce5 ffff880006f47e38 ffffffff81b749fd ffffffff822459b0
[   16.819520]  ffff880000000010 ffff880006f47e48 ffff880006f47de8 ffff003500626476
[   16.819520] Call Trace:
[   16.819520]  [<ffffffff81b7a16b>] dump_stack+0x4c/0x65
[   16.819520]  [<ffffffff810cf061>] ? console_unlock+0x398/0x3c7
[   16.819520]  [<ffffffff81b749fd>] panic+0xc9/0x1f7
[   16.819520]  [<ffffffff824e84aa>] mount_block_root+0x201/0x218
[   16.819520]  [<ffffffff824e871f>] mount_root+0x13f/0x14a
[   16.819520]  [<ffffffff824e92fc>] ? initrd_load+0x2d7/0x2e6
[   16.819520]  [<ffffffff824e8897>] prepare_namespace+0x16d/0x1a6
[   16.819520]  [<ffffffff824e815a>] kernel_init_freeable+0x268/0x278
[   16.819520]  [<ffffffff81b6bb61>] ? rest_init+0xca/0xca
[   16.819520]  [<ffffffff81b6bb6f>] kernel_init+0xe/0xda
[   16.819520]  [<ffffffff81b881fc>] ret_from_fork+0x7c/0xb0
[   16.819520]  [<ffffffff81b6bb61>] ? rest_init+0xca/0xca
[   16.819520] Kernel Offset: 0x0 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffff9fffffff)

Elapsed time: 20


Thanks,
Huang, Ying