init: add bdev fs printk if mount_block_root failed

Booting with the QEMU command line:
"qemu-system-x86_64 -append root=/dev/vda rootfstype=ext4 ..."
will panic if ext4 is not builtin and a request to load the ext4 module
fails.

[    1.729006] VFS: Cannot open root device "vda" or unknown-block(253,0): error -19
[    1.730603] Please append a correct "root=" boot option; here are the available partitions:
[    1.732323] fd00          256000 vda
[    1.732329]  driver: virtio_blk
[    1.734194] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(253,0)
[    1.734771] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.4.0-rc2+ #53
[    1.735194] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.10.2-1ubuntu1 04/01/2014
[    1.735772] Call Trace:
[    1.735950]  <TASK>
[    1.736113]  dump_stack_lvl+0x32/0x50
[    1.736367]  panic+0x108/0x310
[    1.736570]  mount_block_root+0x161/0x310
[    1.736849]  ? rdinit_setup+0x40/0x40
[    1.737088]  prepare_namespace+0x10c/0x180
[    1.737393]  kernel_init_freeable+0x354/0x450
[    1.737707]  ? rest_init+0xd0/0xd0
[    1.737945]  kernel_init+0x16/0x130
[    1.738196]  ret_from_fork+0x1f/0x30

As a hint, print all the bdev fstypes which are available.

[akpm@linux-foundation.org: fix spelling in printk message]
Link: https://lkml.kernel.org/r/20230518035321.1672-1-angus.chen@jaguarmicro.com
Signed-off-by: Angus Chen <angus.chen@jaguarmicro.com>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Angus Chen 2023-05-18 11:53:21 +08:00 committed by Andrew Morton
parent e0ddec73fd
commit 6aee6723f1

View File

@ -427,8 +427,19 @@ retry:
printk("VFS: Cannot open root device \"%s\" or %s: error %d\n",
root_device_name, b, err);
printk("Please append a correct \"root=\" boot option; here are the available partitions:\n");
printk_all_partitions();
if (root_fs_names)
num_fs = list_bdev_fs_names(fs_names, PAGE_SIZE);
if (!num_fs)
pr_err("Can't find any bdev filesystem to be used for mount!\n");
else {
pr_err("List of all bdev filesystems:\n");
for (i = 0, p = fs_names; i < num_fs; i++, p += strlen(p)+1)
pr_err(" %s", p);
pr_err("\n");
}
panic("VFS: Unable to mount root fs on %s", b);
}
if (!(flags & SB_RDONLY)) {