From: Lai Siyao <lai.siyao@intel.com>
Date: Thu, 14 Aug 2014 13:22:50 +0000 (+0800)
Subject: LU-5461 mdc: don't add to page cache upon failure
X-Git-Tag: 2.6.92~52
X-Git-Url: https://git.whamcloud.com/?p=fs%2Flustre-release.git;a=commitdiff_plain;h=2e1472489481ddef9956db8008d63a78c7c84289

LU-5461 mdc: don't add to page cache upon failure

Reading directory pages may fail on MDS, in this case client should
not cache a non-up-to-date directory page, because it will cause
a later read on the same page fail.

Add sanity 242 for this.

Signed-off-by: Lai Siyao <lai.siyao@intel.com>
Change-Id: Icbb55c0ecc4b88913b08ac8998c2673ec15b18ea
Reviewed-on: http://review.whamcloud.com/11450
Tested-by: Jenkins
Reviewed-by: Fan Yong <fan.yong@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
---

diff --git a/lustre/mdc/mdc_request.c b/lustre/mdc/mdc_request.c
index 7fb41ec..d655f9c 100644
--- a/lustre/mdc/mdc_request.c
+++ b/lustre/mdc/mdc_request.c
@@ -1352,6 +1352,14 @@ struct readpage_param {
 	struct md_callback	*rp_cb;
 };
 
+#ifndef HAVE_DELETE_FROM_PAGE_CACHE
+static inline void delete_from_page_cache(struct page *page)
+{
+	remove_from_page_cache(page);
+	page_cache_release(page);
+}
+#endif
+
 /**
  * Read pages from server.
  *
@@ -1401,7 +1409,10 @@ static int mdc_read_page_remote(void *data, struct page *page0)
 
 	rc = mdc_getpage(rp->rp_exp, fid, rp->rp_off, op_data->op_capa1,
 			 page_pool, npages, &req);
-	if (rc == 0) {
+	if (rc < 0) {
+		/* page0 is special, which was added into page cache early */
+		delete_from_page_cache(page0);
+	} else {
 		int lu_pgs;
 
 		rd_pgs = (req->rq_bulk->bd_nob_transferred +
@@ -1416,8 +1427,8 @@ static int mdc_read_page_remote(void *data, struct page *page0)
 
 		SetPageUptodate(page0);
 	}
-
 	unlock_page(page0);
+
 	ptlrpc_req_finished(req);
 	CDEBUG(D_CACHE, "read %d/%d pages\n", rd_pgs, npages);
 	for (i = 1; i < npages; i++) {
diff --git a/lustre/tests/sanity.sh b/lustre/tests/sanity.sh
index d7c9ad3..5e9f63a 100644
--- a/lustre/tests/sanity.sh
+++ b/lustre/tests/sanity.sh
@@ -12762,6 +12762,19 @@ test_241() {
 }
 run_test 241 "bio vs dio"
 
+test_242() {
+	mkdir -p $DIR/$tdir
+	touch $DIR/$tdir/$tfile
+
+	#define OBD_FAIL_MDS_READPAGE_PACK	0x105
+	do_facet mds1 lctl set_param fail_loc=0x105
+	/bin/ls $DIR/$tdir && error "ls $DIR/$tdir should fail"
+
+	do_facet mds1 lctl set_param fail_loc=0
+	/bin/ls $DIR/$tdir || error "ls $DIR/$tdir failed"
+}
+run_test 242 "mdt_readpage failure should not cause directory unreadable"
+
 cleanup_test_300() {
 	trap 0
 	umask $SAVE_UMASK