NFS: Don't corrupt the value of pg_bytes_written in nfs_do_recoalesce()

commit 0d0ea309357dea0d85a82815f02157eb7fcda39f upstream.

The value of mirror->pg_bytes_written should only be updated after a
successful attempt to flush out the requests on the list.

Fixes: a7d42ddb3099 ("nfs: add mirroring support to pgio layer")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index f5de58c5773f6cfcbbda64340631cc555e835214..18868e318b03858d8c54968c808c8f4aa31d789b 100644 (file)
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -993,17 +993,16 @@ static void nfs_pageio_doio(struct nfs_pageio_descriptor *desc)
 {
        struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
 
-
        if (!list_empty(&mirror->pg_list)) {
                int error = desc->pg_ops->pg_doio(desc);
                if (error < 0)
                        desc->pg_error = error;
-               else
+               if (list_empty(&mirror->pg_list)) {
                        mirror->pg_bytes_written += mirror->pg_count;
-       }
-       if (list_empty(&mirror->pg_list)) {
-               mirror->pg_count = 0;
-               mirror->pg_base = 0;
+                       mirror->pg_count = 0;
+                       mirror->pg_base = 0;
+                       mirror->pg_recoalesce = 0;
+               }
        }
 }
 
@@ -1089,7 +1088,6 @@ static int nfs_do_recoalesce(struct nfs_pageio_descriptor *desc)
 
        do {
                list_splice_init(&mirror->pg_list, &head);
-               mirror->pg_bytes_written -= mirror->pg_count;
                mirror->pg_count = 0;
                mirror->pg_base = 0;
                mirror->pg_recoalesce = 0;