fd->lock added to protect transactions for accessing and modifying fd->_ctx.

fd->_ctx access and modifications are now protected by fd->lock.

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

2 files changed, 64 insertions, 33 deletions

diff --git a/libglusterfs/src/fd.c b/libglusterfs/src/fd.c
index 78c578842..bbd15201c 100644
--- a/libglusterfs/src/fd.c
+++ b/libglusterfs/src/fd.c
@@ -415,6 +415,8 @@ fd_destroy (fd_t *fd)
 			}
 		}
         }
+        
+        LOCK_DESTROY (&fd->lock);
 
 	FREE (fd->_ctx);
         inode_unref (fd->inode);
@@ -489,6 +491,8 @@ fd_create (inode_t *inode, pid_t pid)
         fd->pid = pid;
         INIT_LIST_HEAD (&fd->inode_list);
         
+        LOCK_INIT (&fd->lock);
+
         LOCK (&inode->lock);
         fd = _fd_ref (fd);
         UNLOCK (&inode->lock);
@@ -543,45 +547,61 @@ int
 fd_ctx_set (fd_t *fd, xlator_t *xlator, uint64_t value)
 {
 	int index = 0;
+        int ret = 0;
 
 	if (!fd || !xlator)
 		return -1;
-
-	for (index = 0; index < xlator->ctx->xl_count; index++) {
-		if (!fd->_ctx[index].key || 
-		    (fd->_ctx[index].key == (uint64_t)(long)xlator))
-			break;
-	}
+        
+        LOCK (&fd->lock);
+        {
+                for (index = 0; index < xlator->ctx->xl_count; index++) {
+                        if (!fd->_ctx[index].key || 
+                            (fd->_ctx[index].key == (uint64_t)(long)xlator))
+                                break;
+                }
 	
-	if (index == xlator->ctx->xl_count)
-		return -1;
+                if (index == xlator->ctx->xl_count) {
+                        ret = -1;
+                        goto unlock;
+                }
 
-	fd->_ctx[index].key   = (uint64_t)(long) xlator;
-	fd->_ctx[index].value = value;
+                fd->_ctx[index].key   = (uint64_t)(long) xlator;
+                fd->_ctx[index].value = value;
+        }
+unlock:
+        UNLOCK (&fd->lock);
 
-	return 0;
+	return ret;
 }
 
 int 
 fd_ctx_get (fd_t *fd, xlator_t *xlator, uint64_t *value)
 {
 	int index = 0;
+        int ret = 0;
 
 	if (!fd || !xlator)
 		return -1;
+        
+        LOCK (&fd->lock);
+        {
+                for (index = 0; index < xlator->ctx->xl_count; index++) {
+                        if (fd->_ctx[index].key == (uint64_t)(long)xlator)
+                                break;
+                }
 
-	for (index = 0; index < xlator->ctx->xl_count; index++) {
-		if (fd->_ctx[index].key == (uint64_t)(long)xlator)
-			break;
-	}
-
-	if (index == xlator->ctx->xl_count)
-		return -1;
+                if (index == xlator->ctx->xl_count) {
+                        ret = -1;
+                        goto unlock;
+                }
 
-	if (value) 
-		*value = fd->_ctx[index].value;
+                if (value) 
+                        *value = fd->_ctx[index].value;
+        }
+unlock:
+        UNLOCK (&fd->lock);
 
-	return 0;
+	return ret;
 }
 
 
@@ -589,23 +609,31 @@ int
 fd_ctx_del (fd_t *fd, xlator_t *xlator, uint64_t *value)
 {
 	int index = 0;
+        int ret = 0;
 
 	if (!fd || !xlator)
 		return -1;
+        
+        LOCK (&fd->lock);
+        {
+                for (index = 0; index < xlator->ctx->xl_count; index++) {
+                        if (fd->_ctx[index].key == (uint64_t)(long)xlator)
+                                break;
+                }
 
-	for (index = 0; index < xlator->ctx->xl_count; index++) {
-		if (fd->_ctx[index].key == (uint64_t)(long)xlator)
-			break;
-	}
-
-	if (index == xlator->ctx->xl_count)
-		return -1;
+                if (index == xlator->ctx->xl_count) {
+                        ret = -1;
+                        goto unlock;
+                }
 
-	if (value) 
-		*value = fd->_ctx[index].value;		
+                if (value) 
+                        *value = fd->_ctx[index].value;		
 
-	fd->_ctx[index].key   = 0;
-	fd->_ctx[index].value = 0;
+                fd->_ctx[index].key   = 0;
+                fd->_ctx[index].value = 0;
+        }
+unlock:
+        UNLOCK (&fd->lock);
 
-	return 0;
+	return ret;
 }
diff --git a/libglusterfs/src/fd.h b/libglusterfs/src/fd.h
index 8b8effdc3..29a79eb76 100644
--- a/libglusterfs/src/fd.h
+++ b/libglusterfs/src/fd.h
@@ -29,6 +29,7 @@
 #include <sys/types.h>
 #include <unistd.h>
 #include "glusterfs.h"
+#include "locking.h"
 
 struct _inode;
 struct _dict;
@@ -44,6 +45,8 @@ struct _fd {
         struct list_head  inode_list;
         struct _inode    *inode;
         struct _dict     *ctx;
+        gf_lock_t         lock; /* used ONLY for manipulating
+                                   'struct _fd_ctx' array (_ctx).*/
 	struct _fd_ctx   *_ctx;
 };
 typedef struct _fd fd_t;