[2/2] ocfs2: fix ocfs2 corrupt when iputting an inode
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Message ID ef080ca3-5d74-e276-17a1-d9e7c7e662c9@huawei.com
State New
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Series
  • [1/2] ocfs2: clear links count in ocfs2_mknod() if an error occurs
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Commit Message

Wangyan May 26, 2020, 7:55 a.m. UTC
In this condition, it will cause an bug on error.
ocfs2_mkdir()
  ->ocfs2_mknod()
    ->ocfs2_mknod_locked()
      ->__ocfs2_mknod_locked()
        //Assume inode->i_generation is genN.
        ->inode->i_generation = osb->s_next_generation++;
        // The inode lockres has been initialized.
        ->ocfs2_populate_inode()
        ->ocfs2_create_new_inode_locks()
            ->An error happened, returned value is non-zero
      // free the start_bit x in bg_blkno
      ->ocfs2_free_suballoc_bits()
    ->...  /* Another process execute mkdir success in this place,
              and it occupied the start_bit x in bg_blkno
              which has been freed before. Its inode->i_generation
              is genN + 1 */
    ->iput(inode)
      ->evict()
        ->ocfs2_evict_inode()
          ->ocfs2_delete_inode()
            ->ocfs2_inode_lock()
              ->ocfs2_inode_lock_update()
                /* Bug on here, genN != genN + 1 */
                ->mlog_bug_on_msg(inode->i_generation !=
                  le32_to_cpu(fe->i_generation))

So, we need not to reclaim the inode when the inode->ip_inode_lockres
has been initialized. It will be freed in iput().

Signed-off-by: Yan Wang <wangyan122@huawei.com>
Reviewed-by: Jun Piao <piaojun@huawei.com>
---
 fs/ocfs2/namei.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Joseph Qi June 1, 2020, 9:01 a.m. UTC | #1
On 2020/5/26 15:55, Wangyan wrote:
> In this condition, it will cause an bug on error.
> ocfs2_mkdir()
>   ->ocfs2_mknod()
>     ->ocfs2_mknod_locked()
>       ->__ocfs2_mknod_locked()
>         //Assume inode->i_generation is genN.
>         ->inode->i_generation = osb->s_next_generation++;
>         // The inode lockres has been initialized.
>         ->ocfs2_populate_inode()
>         ->ocfs2_create_new_inode_locks()
>             ->An error happened, returned value is non-zero
>       // free the start_bit x in bg_blkno
>       ->ocfs2_free_suballoc_bits()
>     ->...  /* Another process execute mkdir success in this place,
>               and it occupied the start_bit x in bg_blkno
>               which has been freed before. Its inode->i_generation
>               is genN + 1 */
>     ->iput(inode)
>       ->evict()
>         ->ocfs2_evict_inode()
>           ->ocfs2_delete_inode()
>             ->ocfs2_inode_lock()
>               ->ocfs2_inode_lock_update()
>                 /* Bug on here, genN != genN + 1 */
>                 ->mlog_bug_on_msg(inode->i_generation !=
>                   le32_to_cpu(fe->i_generation))
> 
> So, we need not to reclaim the inode when the inode->ip_inode_lockres
> has been initialized. It will be freed in iput().
> 
> Signed-off-by: Yan Wang <wangyan122@huawei.com>
> Reviewed-by: Jun Piao <piaojun@huawei.com>
> ---
>  fs/ocfs2/namei.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c
> index e61fdd8972ec..5302992d2bee 100644
> --- a/fs/ocfs2/namei.c
> +++ b/fs/ocfs2/namei.c
> @@ -640,7 +640,8 @@ static int ocfs2_mknod_locked(struct ocfs2_super *osb,
>  	status = __ocfs2_mknod_locked(dir, inode, dev, new_fe_bh,
>  				    parent_fe_bh, handle, inode_ac,
>  				    fe_blkno, suballoc_loc, suballoc_bit);
> -	if (status < 0) {
> +	if (status < 0 && !(OCFS2_I(inode)->ip_inode_lockres.l_flags &
> +				OCFS2_LOCK_INITIALIZED)) {

Each condition in separate line may be better:

if (status < 0 &&
    !(OCFS2_I(inode)->ip_inode_lockres.l_flags & OCFS2_LOCK_INITIALIZED))

And you've missed a fixed tag:
Fixes: b1529a41f777 ("ocfs2: should reclaim the inode if '__ocfs2_mknod_locked' returns an error")

Thanks,
Joseph

>  		u64 bg_blkno = ocfs2_which_suballoc_group(fe_blkno, suballoc_bit);
>  		int tmp = ocfs2_free_suballoc_bits(handle, inode_ac->ac_inode,
>  				inode_ac->ac_bh, suballoc_bit, bg_blkno, 1);
>
Andrew Morton Aug. 7, 2020, 3:49 a.m. UTC | #2
On Mon, 1 Jun 2020 17:01:51 +0800 Joseph Qi <jiangqi903@gmail.com> wrote:

> 
> 
> On 2020/5/26 15:55, Wangyan wrote:
> > In this condition, it will cause an bug on error.
> > ocfs2_mkdir()
> >   ->ocfs2_mknod()
> >     ->ocfs2_mknod_locked()
> >       ->__ocfs2_mknod_locked()
> >         //Assume inode->i_generation is genN.
> >         ->inode->i_generation = osb->s_next_generation++;
> >         // The inode lockres has been initialized.
> >         ->ocfs2_populate_inode()
> >         ->ocfs2_create_new_inode_locks()
> >             ->An error happened, returned value is non-zero
> >       // free the start_bit x in bg_blkno
> >       ->ocfs2_free_suballoc_bits()
> >     ->...  /* Another process execute mkdir success in this place,
> >               and it occupied the start_bit x in bg_blkno
> >               which has been freed before. Its inode->i_generation
> >               is genN + 1 */
> >     ->iput(inode)
> >       ->evict()
> >         ->ocfs2_evict_inode()
> >           ->ocfs2_delete_inode()
> >             ->ocfs2_inode_lock()
> >               ->ocfs2_inode_lock_update()
> >                 /* Bug on here, genN != genN + 1 */
> >                 ->mlog_bug_on_msg(inode->i_generation !=
> >                   le32_to_cpu(fe->i_generation))
> > 
> > So, we need not to reclaim the inode when the inode->ip_inode_lockres
> > has been initialized. It will be freed in iput().
> > 
> > Signed-off-by: Yan Wang <wangyan122@huawei.com>
> > Reviewed-by: Jun Piao <piaojun@huawei.com>
> > ---
> >  fs/ocfs2/namei.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c
> > index e61fdd8972ec..5302992d2bee 100644
> > --- a/fs/ocfs2/namei.c
> > +++ b/fs/ocfs2/namei.c
> > @@ -640,7 +640,8 @@ static int ocfs2_mknod_locked(struct ocfs2_super *osb,
> >  	status = __ocfs2_mknod_locked(dir, inode, dev, new_fe_bh,
> >  				    parent_fe_bh, handle, inode_ac,
> >  				    fe_blkno, suballoc_loc, suballoc_bit);
> > -	if (status < 0) {
> > +	if (status < 0 && !(OCFS2_I(inode)->ip_inode_lockres.l_flags &
> > +				OCFS2_LOCK_INITIALIZED)) {
> 
> Each condition in separate line may be better:
> 
> if (status < 0 &&
>     !(OCFS2_I(inode)->ip_inode_lockres.l_flags & OCFS2_LOCK_INITIALIZED))
> 
> And you've missed a fixed tag:
> Fixes: b1529a41f777 ("ocfs2: should reclaim the inode if '__ocfs2_mknod_locked' returns an error")

And to this one?

Patch
diff mbox series

diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c
index e61fdd8972ec..5302992d2bee 100644
--- a/fs/ocfs2/namei.c
+++ b/fs/ocfs2/namei.c
@@ -640,7 +640,8 @@  static int ocfs2_mknod_locked(struct ocfs2_super *osb,
 	status = __ocfs2_mknod_locked(dir, inode, dev, new_fe_bh,
 				    parent_fe_bh, handle, inode_ac,
 				    fe_blkno, suballoc_loc, suballoc_bit);
-	if (status < 0) {
+	if (status < 0 && !(OCFS2_I(inode)->ip_inode_lockres.l_flags &
+				OCFS2_LOCK_INITIALIZED)) {
 		u64 bg_blkno = ocfs2_which_suballoc_group(fe_blkno, suballoc_bit);
 		int tmp = ocfs2_free_suballoc_bits(handle, inode_ac->ac_inode,
 				inode_ac->ac_bh, suballoc_bit, bg_blkno, 1);