ceph: fix setting of xattrs on async created inodes

Currently when we create a file, we spin up an xattr buffer to send
along with the create request. If we end up doing an async create
however, then we currently pass down a zero-length xattr buffer.

Fix the code to send down the xattr buffer in req->r_pagelist. If the
xattrs span more than a page, however give up and don't try to do an
async create.

Cc: stable@vger.kernel.org
URL: https://bugzilla.redhat.com/show_bug.cgi?id=2063929
Fixes: 9a8d03ca ("ceph: attempt to do async create when possible")
Reported-by: John Fortin <fortinj66@gmail.com>
Reported-by: Sri Ramanujam <sri@ramanujam.io>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

fs/ceph/file.c

@@ -629,9 +629,15 @@ static int ceph_finish_async_create(struct inode *dir, struct dentry *dentry,
 	iinfo.change_attr = 1;
 	ceph_encode_timespec64(&iinfo.btime, &now);
 
-	iinfo.xattr_len = ARRAY_SIZE(xattr_buf);
-	iinfo.xattr_data = xattr_buf;
-	memset(iinfo.xattr_data, 0, iinfo.xattr_len);
+	if (req->r_pagelist) {
+		iinfo.xattr_len = req->r_pagelist->length;
+		iinfo.xattr_data = req->r_pagelist->mapped_tail;
+	} else {
+		/* fake it */
+		iinfo.xattr_len = ARRAY_SIZE(xattr_buf);
+		iinfo.xattr_data = xattr_buf;
+		memset(iinfo.xattr_data, 0, iinfo.xattr_len);
+	}
 
 	in.ino = cpu_to_le64(vino.ino);
 	in.snapid = cpu_to_le64(CEPH_NOSNAP);
@@ -743,6 +749,10 @@ int ceph_atomic_open(struct inode *dir, struct dentry *dentry,
 		err = ceph_security_init_secctx(dentry, mode, &as_ctx);
 		if (err < 0)
 			goto out_ctx;
+		/* Async create can't handle more than a page of xattrs */
+		if (as_ctx.pagelist &&
+		    !list_is_singular(&as_ctx.pagelist->head))
+			try_async = false;
 	} else if (!d_in_lookup(dentry)) {
 		/* If it's not being looked up, it's negative */
 		return -ENOENT;