From: Wengang Wang <wen.gang.wang@oracle.com>
Date: Wed, 21 Jul 2010 23:17:01 +0800
Subject: [Ocfs2-devel] [PATCH V2] Fix the nested PR lock calling issue
In-Reply-To: <20100721144805.GA12822@linux-jjzhang>
References: <20100721144805.GA12822@linux-jjzhang>
Message-ID: <20100721151701.GA3579@laptop.jp.oracle.com>
List-Id: <ocfs2-devel.oss.oracle.com>
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To: ocfs2-devel@oss.oracle.com

On 10-07-21 22:48, Jiaju Zhang wrote:
> Hi,
> 
> This is an improved patch for the bug
> https://bugzilla.novell.com/show_bug.cgi?id=614332
> (also http://oss.oracle.com/bugzilla/show_bug.cgi?id=1278)
> 
> It is a nested PR lock calling issue, the referenced stack trace is
> as:
> smbd          D ffff8800013d0600     0  9522   5608 0x00000000
>  ffff88002ca7fb18 0000000000000282 ffff88002f964500 ffff88002ca7fa98
>  ffff8800013d0600 ffff88002ca7fae0 ffff88002f964340 ffff88002f964340
>  ffff88002ca7ffd8 ffff88002ca7ffd8 ffff88002f964340 ffff88002f964340
> Call Trace:
> [<ffffffff80350425>] schedule_timeout+0x175/0x210
> [<ffffffff8034f580>] wait_for_common+0xf0/0x210
> [<ffffffffa03e12b9>] __ocfs2_cluster_lock+0x3b9/0xa90 [ocfs2]
> [<ffffffffa03e7665>] ocfs2_inode_lock_full_nested+0x255/0xdb0 [ocfs2]
> [<ffffffffa0446019>] ocfs2_get_acl+0x69/0x120 [ocfs2]
> [<ffffffffa0446368>] ocfs2_check_acl+0x28/0x80 [ocfs2]
> [<ffffffff800e3507>] acl_permission_check+0x57/0xb0
> [<ffffffff800e357d>] generic_permission+0x1d/0xc0
> [<ffffffffa03eecea>] ocfs2_permission+0x10a/0x1d0 [ocfs2]
> [<ffffffff800e3f65>] inode_permission+0x45/0x100
> [<ffffffff800d86b3>] sys_chdir+0x53/0x90
> [<ffffffff80007458>] system_call_fastpath+0x16/0x1b
> [<00007f34a4ef6927>] 0x7f34a4ef6927
> 
> Many thanks for your review and comments;)
> 
> Thanks,
> Jiaju
> 
> Signed-off-by: <jjzhang@suse.de>
> Cc: Joel Becker <Joel.Becker@oracle.com>
> Cc: Mark Fasheh <mfasheh@suse.com>
> Cc: Sunil Mushran <sunil.mushran@oracle.com>
> Cc: Tao Ma <tao.ma@oracle.com>
> Cc: Tiger Yang <tiger.yang@oracle.com>
> Cc: Wengang Wang <wen.gang.wang@oracle.com>
> --- 
>  fs/ocfs2/acl.c |   21 +++++++++++++++++----
>  1 files changed, 17 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/ocfs2/acl.c b/fs/ocfs2/acl.c
> index da70229..ecf73f4 100644
> --- a/fs/ocfs2/acl.c
> +++ b/fs/ocfs2/acl.c
> @@ -290,17 +290,30 @@ static int ocfs2_set_acl(handle_t *handle,
>  
>  int ocfs2_check_acl(struct inode *inode, int mask)
>  {
> -	struct posix_acl *acl = ocfs2_get_acl(inode, ACL_TYPE_ACCESS);
> +	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
> +	struct posix_acl *acl;
> +	struct buffer_head *di_bh = NULL;
> +	int ret = -EAGAIN;
> +
> +	if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
> +		return ret;
> +
> +	ret = ocfs2_read_inode_block(inode, &di_bh);
> +	if (ret < 0) {
> +		mlog_errno(ret);
> +		return ret;
> +	}
> +
> +	acl = ocfs2_get_acl_nolock(inode, ACL_TYPE_ACCESS, di_bh);

From here on, you need to release di_bh.

regards,
wengang.
>  
>  	if (IS_ERR(acl))
>  		return PTR_ERR(acl);
>  	if (acl) {
> -		int ret = posix_acl_permission(inode, acl, mask);
> +		ret = posix_acl_permission(inode, acl, mask);
>  		posix_acl_release(acl);
> -		return ret;
>  	}
>  
> -	return -EAGAIN;
> +	return ret;
>  }
>  
>  int ocfs2_acl_chmod(struct inode *inode)