performance/io-cache: pass appropriate op_errno even during successful

reads.

An op_errno equal to ENOENT with op_ret equal to zero is used by
storage/posix xlator to indicate EOF. NFS relies on this protocol
for correct functioning.

Change-Id: I136fbf429a829bd7bd75ce8ce236f9557a418a5d
BUG: 795789
Signed-off-by: Raghavendra G <raghavendra@gluster.com>
Reviewed-on: http://review.gluster.com/2894
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vijay@gluster.com>

4 files changed, 21 insertions, 11 deletions

diff --git a/xlators/performance/io-cache/src/io-cache.c b/xlators/performance/io-cache/src/io-cache.c
index 823bac38d..329668230 100644
--- a/xlators/performance/io-cache/src/io-cache.c
+++ b/xlators/performance/io-cache/src/io-cache.c
@@ -999,7 +999,7 @@ ioc_dispatch_requests (call_frame_t *frame, ioc_inode_t *ioc_inode, fd_t *fd,
                                                 "cache hit for trav_offset=%"
                                                 PRId64"/local_offset=%"PRId64"",
                                                 trav_offset, local_offset);
-                                        waitq = __ioc_page_wakeup (trav);
+                                        waitq = __ioc_page_wakeup (trav, 0);
                                 } else {
                                         /* if waitq already exists, fstat
                                          * revalidate is
@@ -1016,7 +1016,8 @@ ioc_dispatch_requests (call_frame_t *frame, ioc_inode_t *ioc_inode, fd_t *fd,
                                                 local->op_errno = -ret;
                                                 need_validate = 0;
 
-                                                waitq = __ioc_page_wakeup (trav);
+                                                waitq = __ioc_page_wakeup (trav,
+                                                                           0);
                                                 ioc_inode_unlock (ioc_inode);
 
                                                 ioc_waitq_return (waitq);
@@ -1048,7 +1049,7 @@ ioc_dispatch_requests (call_frame_t *frame, ioc_inode_t *ioc_inode, fd_t *fd,
                         if (ret == -1) {
                                 ioc_inode_lock (ioc_inode);
                                 {
-                                        waitq = __ioc_page_wakeup (trav);
+                                        waitq = __ioc_page_wakeup (trav, 0);
                                 }
                                 ioc_inode_unlock (ioc_inode);
 
diff --git a/xlators/performance/io-cache/src/io-cache.h b/xlators/performance/io-cache/src/io-cache.h
index eec24f143..bd60aa4f4 100644
--- a/xlators/performance/io-cache/src/io-cache.h
+++ b/xlators/performance/io-cache/src/io-cache.h
@@ -212,7 +212,7 @@ __ioc_wait_on_page (ioc_page_t *page, call_frame_t *frame, off_t offset,
                   size_t size);
 
 ioc_waitq_t *
-__ioc_page_wakeup (ioc_page_t *page);
+__ioc_page_wakeup (ioc_page_t *page, int32_t op_errno);
 
 void
 ioc_page_flush (ioc_page_t *page);
@@ -228,7 +228,7 @@ ioc_waitq_return (ioc_waitq_t *waitq);
 
 int32_t
 ioc_frame_fill (ioc_page_t *page, call_frame_t *frame, off_t offset,
-                size_t size);
+                size_t size, int32_t op_errno);
 
 #define ioc_inode_lock(ioc_inode)                                       \
         do {                                                            \
diff --git a/xlators/performance/io-cache/src/ioc-inode.c b/xlators/performance/io-cache/src/ioc-inode.c
index 4c48c41d1..a99d5ea99 100644
--- a/xlators/performance/io-cache/src/ioc-inode.c
+++ b/xlators/performance/io-cache/src/ioc-inode.c
@@ -123,7 +123,8 @@ ioc_inode_wakeup (call_frame_t *frame, ioc_inode_t *ioc_inode,
                                 ioc_inode_lock (ioc_inode);
                                 {
                                         page_waitq =
-                                                __ioc_page_wakeup (waiter_page);
+                                                __ioc_page_wakeup (waiter_page,
+                                                                   0);
                                 }
                                 ioc_inode_unlock (ioc_inode);
                                 if (page_waitq)
diff --git a/xlators/performance/io-cache/src/page.c b/xlators/performance/io-cache/src/page.c
index 87a78ecda..d3d74653a 100644
--- a/xlators/performance/io-cache/src/page.c
+++ b/xlators/performance/io-cache/src/page.c
@@ -524,7 +524,8 @@ ioc_fault_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                                         /* wake up all the frames waiting on
                                          * this page, including
                                          * the frame which triggered fault */
-                                        waitq = __ioc_page_wakeup (page);
+                                        waitq = __ioc_page_wakeup (page,
+                                                                   op_errno);
                                 } /* if(page->waitq) */
                         } /* if(!page)...else */
                 } /* if(op_ret < 0)...else */
@@ -650,7 +651,7 @@ err:
 
 int32_t
 __ioc_frame_fill (ioc_page_t *page, call_frame_t *frame, off_t offset,
-                  size_t size)
+                  size_t size, int32_t op_errno)
 {
         ioc_local_t *local      = NULL;
         ioc_fill_t  *fill       = NULL;
@@ -685,7 +686,13 @@ __ioc_frame_fill (ioc_page_t *page, call_frame_t *frame, off_t offset,
         /* immediately move this page to the end of the page_lru list */
         list_move_tail (&page->page_lru, &ioc_inode->cache.page_lru);
         /* fill local->pending_size bytes from local->pending_offset */
-        if (local->op_ret != -1 && page->size) {
+        if (local->op_ret != -1) {
+                local->op_errno = op_errno;
+
+                if (page->size == 0) {
+                        goto done;
+                }
+
                 if (offset > page->offset)
                         /* offset is offset in file, convert it to offset in
                          * page */
@@ -778,6 +785,7 @@ __ioc_frame_fill (ioc_page_t *page, call_frame_t *frame, off_t offset,
                 local->op_ret += copy_size;
         }
 
+done:
         ret = 0;
 out:
         return ret;
@@ -922,7 +930,7 @@ ioc_frame_return (call_frame_t *frame)
  * to be called only when a frame is waiting on an in-transit page
  */
 ioc_waitq_t *
-__ioc_page_wakeup (ioc_page_t *page)
+__ioc_page_wakeup (ioc_page_t *page, int32_t op_errno)
 {
         ioc_waitq_t  *waitq = NULL, *trav = NULL;
         call_frame_t *frame = NULL;
@@ -941,7 +949,7 @@ __ioc_page_wakeup (ioc_page_t *page)
         for (trav = waitq; trav; trav = trav->next) {
                 frame = trav->data;
                 ret = __ioc_frame_fill (page, frame, trav->pending_offset,
-                                        trav->pending_size);
+                                        trav->pending_size, op_errno);
                 if (ret == -1) {
                         break;
                 }