[CIFS] Change semaphore to mutex for cifs lock_sem

Originally at http://lkml.org/lkml/2006/9/2/86

The recent change to "allow Windows blocking locks to be cancelled via a
CANCEL_LOCK call" introduced a new semaphore in struct cifsFileInfo,
lock_sem.  However, semaphores used as mutexes are deprecated these days,
and there's no reason to add a new one to the kernel.  Therefore, convert
lock_sem to a struct mutex (and also fix one indentation glitch on one of
the lines changed anyway).

Signed-off-by: Roland Dreier <roland@digitalvampire.org>
Signed-off-by: Jan Engelhardt <jengelh@gmx.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>

fs/cifs/cifsglob.h

@@ -311,7 +311,7 @@ struct cifsFileInfo {
 	/* lock scope id (0 if none) */
 	struct file * pfile; /* needed for writepage */
 	struct inode * pInode; /* needed for oplock break */
-	struct semaphore lock_sem;
+	struct mutex lock_mutex;
 	struct list_head llist; /* list of byte range locks we have. */
 	unsigned closePend:1;	/* file is marked to close */
 	unsigned invalidHandle:1;  /* file closed via session abend */

fs/cifs/dir.c

@@ -274,7 +274,7 @@ cifs_create(struct inode *inode, struct dentry *direntry, int mode,
 			pCifsFile->invalidHandle = FALSE;
 			pCifsFile->closePend     = FALSE;
 			init_MUTEX(&pCifsFile->fh_sem);
-			init_MUTEX(&pCifsFile->lock_sem);
+			mutex_init(&pCifsFile->lock_mutex);
 			INIT_LIST_HEAD(&pCifsFile->llist);
 			atomic_set(&pCifsFile->wrtPending,0);
 

fs/cifs/file.c

@@ -48,7 +48,7 @@ static inline struct cifsFileInfo *cifs_init_private(
 	private_data->netfid = netfid;
 	private_data->pid = current->tgid;	
 	init_MUTEX(&private_data->fh_sem);
-	init_MUTEX(&private_data->lock_sem);
+	mutex_init(&private_data->lock_mutex);
 	INIT_LIST_HEAD(&private_data->llist);
 	private_data->pfile = file; /* needed for writepage */
 	private_data->pInode = inode;
@@ -511,12 +511,12 @@ int cifs_close(struct inode *inode, struct file *file)
 
 		/* Delete any outstanding lock records.
 		   We'll lose them when the file is closed anyway. */
-		down(&pSMBFile->lock_sem);
+		mutex_lock(&pSMBFile->lock_mutex);
 		list_for_each_entry_safe(li, tmp, &pSMBFile->llist, llist) {
 			list_del(&li->llist);
 			kfree(li);
 		}
-		up(&pSMBFile->lock_sem);
+		mutex_unlock(&pSMBFile->lock_mutex);
 
 		write_lock(&GlobalSMBSeslock);
 		list_del(&pSMBFile->flist);
@@ -601,9 +601,9 @@ static int store_file_lock(struct cifsFileInfo *fid, __u64 len,
 	li->offset = offset;
 	li->length = len;
 	li->type = lockType;
-	down(&fid->lock_sem);
+	mutex_lock(&fid->lock_mutex);
 	list_add(&li->llist, &fid->llist);
-	up(&fid->lock_sem);
+	mutex_unlock(&fid->lock_mutex);
 	return 0;
 }
 
@@ -760,7 +760,7 @@ int cifs_lock(struct file *file, int cmd, struct file_lock *pfLock)
 			struct cifsLockInfo *li, *tmp;
 
 			rc = 0;
-			down(&fid->lock_sem);
+			mutex_lock(&fid->lock_mutex);
 			list_for_each_entry_safe(li, tmp, &fid->llist, llist) {
 				if (pfLock->fl_start <= li->offset &&
 						length >= li->length) {
@@ -774,7 +774,7 @@ int cifs_lock(struct file *file, int cmd, struct file_lock *pfLock)
 					kfree(li);
 				}
 			}
-			up(&fid->lock_sem);
+			mutex_unlock(&fid->lock_mutex);
 		}
 	}