a oops about orphan inode

a oops about orphan inode

[awp47]

hi ,all
recently, I meet a oops in a old kernel(2.6.5-suse9).
General process are:
1.mount a block device: mount -t ext3 -o data=journal /dev/device
/some, it return ok.
2.in userspace, execute the rm commond, and the rm will call sys_unlink():
2.1.sys_unlink() will call path_lookup(), it will call
ext3_lookup()->ext3_read_inode(), it's get a inode from
   disk, but it's inode->i_nlink and inode->i_mode are both 0, so it's
a bad inode(make_bad_inode()).
2.2.after lookup path, sys_unlink() will call
vfs_unlink()->ext3_unlink(), in ext3_unlink() it will find the bad
   inode, and put it in orphan inode list both memory and disk.
2.3.after vfs_unlink(), sys_unlink() will call
iput()->ext3_delete_inode(), in ext3_delete_inode() it will check
   the inode, if it is bad, it will goto end(don't remove orphan inode
from the memory and disk list)
3.umount the block device, at this time, kernel oops in
ext3_put_super(): J_ASSERT(list_empty(&sbi->s_orphan));

can somebody tell me, how to deal with bad inode in kernel? if we get
a bad inode from disk, it will don't remove
from orphan inode list?

I checked the newest stable kernel 3.0.3. ext3_read_inode() change
into ext3_iget(): if we get a bad inode, it will
call iget_failed(), it will mark inode as bad(make_bad_inode) and call
iput(), at last will call ext3_evict_inode. now
in ext3_evict_inode also checked inode, if it is bad, don't remove
from orphan inode list.

Re: a oops about orphan inode

[Jan Kara]

On Mon 22-08-11 23:51:11, awp47 wrote:
> hi ,all
> recently, I meet a oops in a old kernel(2.6.5-suse9).
> General process are:
> 1.mount a block device: mount -t ext3 -o data=journal /dev/device
> /some, it return ok.
> 2.in userspace, execute the rm commond, and the rm will call sys_unlink():
> 2.1.sys_unlink() will call path_lookup(), it will call
> ext3_lookup()->ext3_read_inode(), it's get a inode from
>    disk, but it's inode->i_nlink and inode->i_mode are both 0, so it's
> a bad inode(make_bad_inode()).
> 2.2.after lookup path, sys_unlink() will call
> vfs_unlink()->ext3_unlink(), in ext3_unlink() it will find the bad
>    inode, and put it in orphan inode list both memory and disk.
> 2.3.after vfs_unlink(), sys_unlink() will call
> iput()->ext3_delete_inode(), in ext3_delete_inode() it will check
>    the inode, if it is bad, it will goto end(don't remove orphan inode
> from the memory and disk list)
> 3.umount the block device, at this time, kernel oops in
> ext3_put_super(): J_ASSERT(list_empty(&sbi->s_orphan));
> 
> can somebody tell me, how to deal with bad inode in kernel? if we get
> a bad inode from disk, it will don't remove
> from orphan inode list?
> 
> I checked the newest stable kernel 3.0.3. ext3_read_inode() change
> into ext3_iget(): if we get a bad inode, it will
> call iget_failed(), it will mark inode as bad(make_bad_inode) and call
> iput(), at last will call ext3_evict_inode. now
> in ext3_evict_inode also checked inode, if it is bad, don't remove
> from orphan inode list.
  Hmm, where does it check for bad inode and exit without removing inode
from orphan list? I don't see anything like that in ext3_evict_inode().

  BTW: Sending this question to linux-ext4@vger.kernel.org would have
higher chances of getting some attention.

								Honza
-- 
Jan Kara <jack@suse.cz>
SUSE Labs, CR