Commit 5f6dbc9e authored by Jeff Layton's avatar Jeff Layton Committed by Steve French
Browse files

cifs: convert cifsFileInfo->count to non-atomic counter 



The count for cifsFileInfo is currently an atomic, but that just adds
complexity for little value. We generally need to hold cifs_file_list_lock
to traverse the lists anyway so we might as well make this counter
non-atomic and simply use the cifs_file_list_lock to protect it.

Signed-off-by: default avatarJeff Layton <jlayton@redhat.com>
Reviewed-by: default avatarSuresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: default avatarSteve French <sfrench@us.ibm.com>
parent 229aebb8

fs/cifs/cifsglob.h

+6 −3
Original line number Diff line number Diff line
@@ -395,16 +395,19 @@ 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.

 */

static inline void cifsFileInfo_get(struct cifsFileInfo *cifs_file)

{

	atomic_inc(&cifs_file->count);

	++cifs_file->count;

}



void cifsFileInfo_put(struct cifsFileInfo *cifs_file);

fs/cifs/file.c

+5 −3
Original line number Diff line number Diff line
@@ -232,6 +232,7 @@ 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();
@@ -242,7 +243,6 @@ 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);



	spin_lock(&cifs_file_list_lock);
@@ -267,7 +267,8 @@ 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)

{
@@ -276,7 +277,7 @@ void cifsFileInfo_put(struct cifsFileInfo *cifs_file) 
	struct cifsLockInfo *li, *tmp;



	spin_lock(&cifs_file_list_lock);

	if (!atomic_dec_and_test(&cifs_file->count)) {

	if (--cifs_file->count > 0) {

		spin_unlock(&cifs_file_list_lock);

		return;

	}
@@ -2322,6 +2323,7 @@ void cifs_oplock_break(struct work_struct *work) 
	cifs_oplock_break_put(cfile);

}



/* must be called while holding cifs_file_list_lock */

void cifs_oplock_break_get(struct cifsFileInfo *cfile)

{

	cifs_sb_active(cfile->dentry->d_sb);