[13/15] cifs: convert cifsFileInfo->count to non-atomic counter

Commit Message

Jeff Layton Oct. 6, 2010, 7:54 p.m. UTC

None

Patch

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 531a768..f3c4e00 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -393,16 +393,19 @@  struct cifsFileInfo {
 	struct list_head llist; /* list of byte range locks we have. */
 	bool invalidHandle:1;	/* file closed via session abend */
 	bool oplock_break_cancelled:1;
-	atomic_t count;		/* reference count */
+	int count;		/* refcount -- protected by cifs_file_list_lock */
 	struct mutex fh_mutex; /* prevents reopen race after dead ses*/
 	struct cifs_search_info srch_inf;
 	struct work_struct oplock_break; /* work for oplock breaks */
 };
 
-/* Take a reference on the file private data */
+/*
+ * Take a reference on the file private data. Must be called with
+ * cifs_file_list_lock held for read or write.
+ */
 static inline void cifsFileInfo_get(struct cifsFileInfo *cifs_file)
 {
-	atomic_inc(&cifs_file->count);
+	++cifs_file->count;
 }
 
 void cifsFileInfo_put(struct cifsFileInfo *cifs_file);
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 157ab9d..3a917be 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -172,6 +172,7 @@  cifs_new_fileinfo(__u16 fileHandle, struct file *file,
 	if (pCifsFile == NULL)
 		return pCifsFile;
 
+	pCifsFile->count = 1;
 	pCifsFile->netfid = fileHandle;
 	pCifsFile->pid = current->tgid;
 	pCifsFile->uid = current_fsuid();
@@ -182,7 +183,6 @@  cifs_new_fileinfo(__u16 fileHandle, struct file *file,
 	mutex_init(&pCifsFile->fh_mutex);
 	mutex_init(&pCifsFile->lock_mutex);
 	INIT_LIST_HEAD(&pCifsFile->llist);
-	atomic_set(&pCifsFile->count, 1);
 	INIT_WORK(&pCifsFile->oplock_break, cifs_oplock_break);
 
 	write_lock(&cifs_file_list_lock);
@@ -208,7 +208,8 @@  cifs_new_fileinfo(__u16 fileHandle, struct file *file,
 
 /*
  * Release a reference on the file private data. This may involve closing
- * the filehandle out on the server.
+ * the filehandle out on the server. Must be called without holding
+ * cifs_file_list_lock.
  */
 void cifsFileInfo_put(struct cifsFileInfo *cifs_file)
 {
@@ -217,7 +218,7 @@  void cifsFileInfo_put(struct cifsFileInfo *cifs_file)
 	struct cifsLockInfo *li, *tmp;
 
 	write_lock(&cifs_file_list_lock);
-	if (!atomic_dec_and_test(&cifs_file_list_lock)) {
+	if (--cifs_file->count > 0) {
 		write_unlock(&cifs_file_list_lock);
 		return;
 	}
@@ -2259,6 +2260,7 @@  void cifs_oplock_break(struct work_struct *work)
 	cifs_oplock_break_put(cfile);
 }
 
+/* must be called while holding cifs_file_list_lock for read or write */
 void cifs_oplock_break_get(struct cifsFileInfo *cfile)
 {
 	cifs_sb_active(cfile->dentry->d_sb);