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: a7d42dd ("nfs: add mirroring support to pgio layer") Signed-off-by: Trond Myklebust <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
akeromi · Jun 3, 2021 · 40f139a · 40f139a
1 parent 945ebef
commit 40f139a
Showing 1 changed file with 5 additions and 7 deletions.
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
@@ -987,17 +987,16 @@ 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;
+		}
 	}
 }
 
@@ -1095,7 +1094,6 @@ 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;