cifs: add refcounting to cifs_readdata structures

This isn't strictly necessary for the async readpages code, but the
uncached version will need to be able to collect the replies after
issuing the calls. Add a kref to cifs_readdata and use change the
code to take and put references appropriately.

Signed-off-by: Jeff Layton <jlayton@redhat.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 3aa1fcc15156..45633da461a8 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -1635,12 +1635,15 @@ cifs_async_readv(struct cifs_readdata *rdata)
         rdata->iov[0].iov_base = smb;
         rdata->iov[0].iov_len = be32_to_cpu(smb->hdr.smb_buf_length) + 4;
 
+        kref_get(&rdata->refcount);
         rc = cifs_call_async(tcon->ses->server, rdata->iov, 1,
                              cifs_readv_receive, cifs_readv_callback,
                              rdata, false);
 
         if (rc == 0)
                 cifs_stats_inc(&tcon->num_reads);
+        else
+                kref_put(&rdata->refcount, cifs_readdata_release);
 
         cifs_small_buf_release(smb);
         return rc;