tree f8f998acb306c25992468d0a52e9082616b37ea5
parent 3eb2ce825ea1ad89d20f7a3b5780df850e4be274
author Yan, Zheng <zyan@redhat.com> 1521170549 +0800
committer Ilya Dryomov <idryomov@gmail.com> 1522401468 +0200

ceph: only dirty ITER_IOVEC pages for direct read

If a page is already locked, attempting to dirty it leads to a deadlock
in lock_page().  This is what currently happens to ITER_BVEC pages when
a dio-enabled loop device is backed by ceph:

  $ losetup --direct-io /dev/loop0 /mnt/cephfs/img
  $ xfs_io -c 'pread 0 4k' /dev/loop0

Follow other file systems and only dirty ITER_IOVEC pages.

Cc: stable@kernel.org
Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>