performance/open-behind: Pass O_DIRECT flags for anon fd reads when required

        Backport of: http://review.gluster.org/15537
        cherry-picked from a412a4f50d8ca2ae68dbfa93b80757889150ce99

Writes are already passing the correct flags at the time of open().

Also, make io-cache honor direct-io for anon-fds with
O_DIRECT flag during reads.

Change-Id: Iba1a5c2c9e5fe334ba199cdbffd5b08764218460
BUG: 1378814
Signed-off-by: Krutika Dhananjay <kdhananj@redhat.com>
Reviewed-on: http://review.gluster.org/15553
Smoke: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>

2 files changed, 28 insertions, 39 deletions

diff --git a/xlators/performance/io-cache/src/io-cache.c b/xlators/performance/io-cache/src/io-cache.c
index 46e26bcdc1a..98c37746921 100644
--- a/xlators/performance/io-cache/src/io-cache.c
+++ b/xlators/performance/io-cache/src/io-cache.c
@@ -893,29 +893,6 @@ ioc_release (xlator_t *this, fd_t *fd)
         return 0;
 }
 
-/*
- * ioc_readv_disabled_cbk
- * @frame:
- * @cookie:
- * @this:
- * @op_ret:
- * @op_errno:
- * @vector:
- * @count:
- *
- */
-int32_t
-ioc_readv_disabled_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
-                        int32_t op_ret,	int32_t op_errno, struct iovec *vector,
-                        int32_t count, struct iatt *stbuf,
-                        struct iobref *iobref, dict_t *xdata)
-{
-        STACK_UNWIND_STRICT (readv, frame, op_ret, op_errno, vector, count,
-                             stbuf, iobref, xdata);
-        return 0;
-}
-
-
 int32_t
 ioc_need_prune (ioc_table_t *table)
 {
@@ -1128,10 +1105,17 @@ ioc_readv (call_frame_t *frame, xlator_t *this, fd_t *fd,
         ioc_inode = (ioc_inode_t *)(long)tmp_ioc_inode;
         if (!ioc_inode) {
                 /* caching disabled, go ahead with normal readv */
-                STACK_WIND (frame, ioc_readv_disabled_cbk,
-                            FIRST_CHILD (frame->this),
-                            FIRST_CHILD (frame->this)->fops->readv, fd, size,
-                            offset, flags, xdata);
+                STACK_WIND_TAIL (frame, FIRST_CHILD (frame->this),
+                                 FIRST_CHILD (frame->this)->fops->readv, fd,
+                                 size, offset, flags, xdata);
+                return 0;
+        }
+
+        if (flags & O_DIRECT) {
+                /* disable caching for this fd, if O_DIRECT is used */
+                STACK_WIND_TAIL (frame, FIRST_CHILD (frame->this),
+                                 FIRST_CHILD (frame->this)->fops->readv, fd,
+                                 size, offset, flags, xdata);
                 return 0;
         }
 
@@ -1165,10 +1149,9 @@ ioc_readv (call_frame_t *frame, xlator_t *this, fd_t *fd,
 
         if (!fd_ctx_get (fd, this, NULL)) {
                 /* disable caching for this fd, go ahead with normal readv */
-                STACK_WIND (frame, ioc_readv_disabled_cbk,
-                            FIRST_CHILD (frame->this),
-                            FIRST_CHILD (frame->this)->fops->readv, fd, size,
-                            offset, flags, xdata);
+                STACK_WIND_TAIL (frame, FIRST_CHILD (frame->this),
+                                 FIRST_CHILD (frame->this)->fops->readv, fd,
+                                 size, offset, flags, xdata);
                 return 0;
         }
 
diff --git a/xlators/performance/open-behind/src/open-behind.c b/xlators/performance/open-behind/src/open-behind.c
index efab88582ff..00e8906910a 100644
--- a/xlators/performance/open-behind/src/open-behind.c
+++ b/xlators/performance/open-behind/src/open-behind.c
@@ -351,19 +351,25 @@ err:
 
 
 fd_t *
-ob_get_wind_fd (xlator_t *this, fd_t *fd)
+ob_get_wind_fd (xlator_t *this, fd_t *fd, uint32_t *flag)
 {
-	ob_conf_t  *conf = NULL;
-	ob_fd_t    *ob_fd = NULL;
+        fd_t       *wind_fd = NULL;
+	ob_fd_t    *ob_fd   = NULL;
+	ob_conf_t  *conf    = NULL;
 
 	conf = this->private;
 
 	ob_fd = ob_fd_ctx_get (this, fd);
 
-	if (ob_fd && conf->use_anonymous_fd)
-		return fd_anonymous (fd->inode);
+	if (ob_fd && conf->use_anonymous_fd) {
+                wind_fd = fd_anonymous (fd->inode);
+                if ((ob_fd->flags & O_DIRECT) && (flag))
+                        *flag = *flag | O_DIRECT;
+        } else {
+                wind_fd = fd_ref (fd);
+        }
 
-	return fd_ref (fd);
+	return wind_fd;
 }
 
 
@@ -378,7 +384,7 @@ ob_readv (call_frame_t *frame, xlator_t *this, fd_t *fd, size_t size,
         conf = this->private;
 
         if (!conf->read_after_open)
-                wind_fd = ob_get_wind_fd (this, fd);
+                wind_fd = ob_get_wind_fd (this, fd, &flags);
         else
                 wind_fd = fd_ref (fd);
 
@@ -427,7 +433,7 @@ ob_fstat (call_frame_t *frame, xlator_t *this, fd_t *fd, dict_t *xdata)
 	call_stub_t  *stub = NULL;
 	fd_t         *wind_fd = NULL;
 
-	wind_fd = ob_get_wind_fd (this, fd);
+	wind_fd = ob_get_wind_fd (this, fd, NULL);
 
 	stub = fop_fstat_stub (frame, default_fstat_resume, wind_fd, xdata);