ceph: try getting buffer capability for readahead/fadvise

For readahead/fadvise cases, caller of ceph_readpages does not
hold buffer capability. Pages can be added to page cache while
there is no buffer capability. This can cause data integrity
issue.

Signed-off-by: Yan, Zheng <zyan@redhat.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 10cd6acad44c..ae3cec5724d6 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -1249,8 +1249,9 @@ again:
                 dout("aio_read %p %llx.%llx %llu~%u got cap refs on %s\n",
                      inode, ceph_vinop(inode), iocb->ki_pos, (unsigned)len,
                      ceph_cap_string(got));
-
+                current->journal_info = filp;
                 ret = generic_file_read_iter(iocb, to);
+                current->journal_info = NULL;
         }
         dout("aio_read %p %llx.%llx dropping cap refs on %s = %d\n",
              inode, ceph_vinop(inode), ceph_cap_string(got), (int)ret);