check for fd ctx set in changelog_needed_post_op for flush() in afr

Earlier the check was in afr_flush(), which caused race conditions
with writev()

Signed-off-by: Anand V. Avati <avati@amp.gluster.com>

2 files changed, 49 insertions, 95 deletions

diff --git a/xlators/cluster/afr/src/afr-transaction.c b/xlators/cluster/afr/src/afr-transaction.c
index 6a1f228a6c0..82c2ee3406f 100644
--- a/xlators/cluster/afr/src/afr-transaction.c
+++ b/xlators/cluster/afr/src/afr-transaction.c
@@ -89,6 +89,26 @@ __is_first_write_on_fd (xlator_t *this, fd_t *fd)
 
 
 static int
+__unset_fd_ctx_if_set (xlator_t *this, fd_t *fd)
+{
+        int op_ret = 0;
+        int _ret   = -1;
+
+        LOCK (&fd->inode->lock);
+        {
+                _ret = fd_ctx_get (fd, this, NULL);
+                if (_ret == 0) {
+                        fd_ctx_del (fd, this, NULL);
+                        op_ret = 1;
+                }
+        }
+        UNLOCK (&fd->inode->lock);
+
+        return op_ret;
+}
+
+
+static int
 __changelog_enabled (afr_private_t *priv, afr_transaction_type type)
 {
 	int ret = 0;
@@ -170,19 +190,31 @@ __changelog_needed_post_op (call_frame_t *frame, xlator_t *this)
 	afr_private_t * priv  = NULL;
 	afr_local_t   * local = NULL;
 
-	int ret = 0;
+	int op_ret = 0;
 	afr_transaction_type type = -1;
 
 	priv  = this->private;
 	local = frame->local;
 	type  = local->transaction.type;
 
-	if (__changelog_enabled (priv, type)
-	    && (local->op != GF_FOP_WRITE)
-	    && (local->op != GF_FOP_FTRUNCATE))
-		ret = 1;
-	
-	return ret;
+	if (__changelog_enabled (priv, type)) {
+                switch (local->op) {
+
+                case GF_FOP_WRITE:
+                case GF_FOP_FTRUNCATE:
+                        op_ret = 0;
+                        break;
+
+                case GF_FOP_FLUSH:
+                        op_ret = __unset_fd_ctx_if_set (this, local->fd);
+                        break;
+
+                default:
+                        op_ret = 1;
+                }
+        }
+
+	return op_ret;
 }
 
 
diff --git a/xlators/cluster/afr/src/afr.c b/xlators/cluster/afr/src/afr.c
index da6a31f6f9a..acd7f8d0236 100644
--- a/xlators/cluster/afr/src/afr.c
+++ b/xlators/cluster/afr/src/afr.c
@@ -762,62 +762,16 @@ afr_flush_done (call_frame_t *frame, xlator_t *this)
 
 
 int
-afr_simple_flush_cbk (call_frame_t *frame, void *cookie,
-		      xlator_t *this, int32_t op_ret, int32_t op_errno)
-{
-        afr_local_t *local = NULL;
-        
-        int call_count = -1;
-	
-        local = frame->local;
-	
-        LOCK (&frame->lock);
-        {
-                if (op_ret == 0)
-                        local->op_ret = 0;
-
-                local->op_errno = op_errno;
-        }
-        UNLOCK (&frame->lock);
-	
-        call_count = afr_frame_return (frame);
-	
-        if (call_count == 0)
-                AFR_STACK_UNWIND (frame, local->op_ret, local->op_errno);
-	
-        return 0;
-}
-
-
-static int
-__is_fd_ctx_set (xlator_t *this, fd_t *fd)
-{
-	int _ret   = 0;
-	int op_ret = 0;
-
-	_ret = fd_ctx_get (fd, this, NULL);
-	if (_ret == 0)
-		op_ret = 1;
-
-	return op_ret;
-}
-
-
-int
 afr_flush (call_frame_t *frame, xlator_t *this, fd_t *fd)
 {
 	afr_private_t * priv  = NULL;
 	afr_local_t   * local = NULL;
 
 	int ret        = -1;
-	int i          = 0;
-	int call_count = 0;
 
 	int op_ret   = -1;
 	int op_errno = 0;
 
-        int transaction_needed = 0;
-
 	VALIDATE_OR_GOTO (frame, out);
 	VALIDATE_OR_GOTO (this, out);
 	VALIDATE_OR_GOTO (this->private, out);
@@ -834,50 +788,18 @@ afr_flush (call_frame_t *frame, xlator_t *this, fd_t *fd)
 
 	frame->local = local;
 
-        LOCK (&fd->inode->lock);
-        {
-                if (__is_fd_ctx_set (this, fd)) {
-                        transaction_needed = 1;
-                        fd_ctx_del (fd, this, NULL);
-                } else {
-                        transaction_needed = 0;
-                }
-        }
-        UNLOCK (&fd->inode->lock);
-
-        if (transaction_needed) {
-		local->op = GF_FOP_FLUSH;
-		local->transaction.fop    = afr_flush_wind;
-		local->transaction.done   = afr_flush_done;
-		
-		local->fd                 = fd_ref (fd);
-		
-		local->transaction.start  = 0;
-		local->transaction.len    = 0;
-		
-		local->transaction.pending = AFR_DATA_PENDING;
-		
-		afr_transaction (frame, this, AFR_FLUSH_TRANSACTION);
-	} else {
-		/*
-		 * if fd's ctx is not set, then there is no need
-		 * to erase changelog. So just send the flush
-		 */
+        local->op = GF_FOP_FLUSH;
+        local->transaction.fop    = afr_flush_wind;
+        local->transaction.done   = afr_flush_done;
 
-		call_count = local->call_count;
+        local->fd                 = fd_ref (fd);
 
-		for (i = 0; i < priv->child_count; i++) {
-			if (local->child_up[i]) {
-				STACK_WIND (frame, afr_simple_flush_cbk,
-					    priv->children[i],
-					    priv->children[i]->fops->flush,
-					    fd);
-
-				if (!--call_count)
-					break;
-			}
-		}
-	}
+        local->transaction.start  = 0;
+        local->transaction.len    = 0;
+
+        local->transaction.pending = AFR_DATA_PENDING;
+
+        afr_transaction (frame, this, AFR_FLUSH_TRANSACTION);
 
 	op_ret = 0;
 out: