ocfs2: fix posix_acl_create deadlock

Commit 702e5bc68ad2 ("ocfs2: use generic posix ACL infrastructure")
refactored code to use posix_acl_create.  The problem with this function
is that it is not mindful of the cluster wide inode lock making it
unsuitable for use with ocfs2 inode creation with ACLs.  For example,
when used in ocfs2_mknod, this function can cause deadlock as follows.
The parent dir inode lock is taken when calling posix_acl_create ->
get_acl -> ocfs2_iop_get_acl which takes the inode lock again.  This can
cause deadlock if there is a blocked remote lock request waiting for the
lock to be downconverted.  And same deadlock happened in ocfs2_reflink.
This fix is to revert back using ocfs2_init_acl.

Fixes: 702e5bc68ad2 ("ocfs2: use generic posix ACL infrastructure")
Signed-off-by: Tariq Saeed <tariq.x.saeed@oracle.com>
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 63 insertions, 0 deletions

diff --git a/fs/ocfs2/acl.c b/fs/ocfs2/acl.c
index 749d3bc41232..2162434728c0 100644
--- a/fs/ocfs2/acl.c
+++ b/fs/ocfs2/acl.c
@@ -346,3 +346,66 @@ int ocfs2_acl_chmod(struct inode *inode, struct buffer_head *bh)
 	posix_acl_release(acl);
 	return ret;
 }
+
+/*
+ * Initialize the ACLs of a new inode. If parent directory has default ACL,
+ * then clone to new inode. Called from ocfs2_mknod.
+ */
+int ocfs2_init_acl(handle_t *handle,
+		   struct inode *inode,
+		   struct inode *dir,
+		   struct buffer_head *di_bh,
+		   struct buffer_head *dir_bh,
+		   struct ocfs2_alloc_context *meta_ac,
+		   struct ocfs2_alloc_context *data_ac)
+{
+	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+	struct posix_acl *acl = NULL;
+	int ret = 0, ret2;
+	umode_t mode;
+
+	if (!S_ISLNK(inode->i_mode)) {
+		if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) {
+			acl = ocfs2_get_acl_nolock(dir, ACL_TYPE_DEFAULT,
+						   dir_bh);
+			if (IS_ERR(acl))
+				return PTR_ERR(acl);
+		}
+		if (!acl) {
+			mode = inode->i_mode & ~current_umask();
+			ret = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
+			if (ret) {
+				mlog_errno(ret);
+				goto cleanup;
+			}
+		}
+	}
+	if ((osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) && acl) {
+		if (S_ISDIR(inode->i_mode)) {
+			ret = ocfs2_set_acl(handle, inode, di_bh,
+					    ACL_TYPE_DEFAULT, acl,
+					    meta_ac, data_ac);
+			if (ret)
+				goto cleanup;
+		}
+		mode = inode->i_mode;
+		ret = __posix_acl_create(&acl, GFP_NOFS, &mode);
+		if (ret < 0)
+			return ret;
+
+		ret2 = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
+		if (ret2) {
+			mlog_errno(ret2);
+			ret = ret2;
+			goto cleanup;
+		}
+		if (ret > 0) {
+			ret = ocfs2_set_acl(handle, inode,
+					    di_bh, ACL_TYPE_ACCESS,
+					    acl, meta_ac, data_ac);
+		}
+	}
+cleanup:
+	posix_acl_release(acl);
+	return ret;
+}