[Ocfs2-devel] [PATCH V2] Fix the nested PR lock calling issue

[Jiaju Zhang <jjzhang.linux@gmail.com>]

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);
 
 	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)