cifs: protect GlobalOplock_Q with its own spinlock

Right now, the GlobalOplock_Q is protected by the GlobalMid_Lock. That
lock is also used for completely unrelated purposes (mostly for managing
the global mid queue). Give the list its own dedicated spinlock
(cifs_oplock_lock) and rename the list to cifs_oplock_list to
eliminate the camel-case.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index b750aa5..3610e99 100644 (file)
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -986,19 +986,19 @@ static int cifs_oplock_thread(void *dummyarg)
                if (try_to_freeze())
                        continue;
 
-               spin_lock(&GlobalMid_Lock);
-               if (list_empty(&GlobalOplock_Q)) {
-                       spin_unlock(&GlobalMid_Lock);
+               spin_lock(&cifs_oplock_lock);
+               if (list_empty(&cifs_oplock_list)) {
+                       spin_unlock(&cifs_oplock_lock);
                        set_current_state(TASK_INTERRUPTIBLE);
                        schedule_timeout(39*HZ);
                } else {
-                       oplock_item = list_entry(GlobalOplock_Q.next,
+                       oplock_item = list_entry(cifs_oplock_list.next,
                                                struct oplock_q_entry, qhead);
                        cFYI(1, ("found oplock item to write out"));
                        pTcon = oplock_item->tcon;
                        inode = oplock_item->pinode;
                        netfid = oplock_item->netfid;
-                       spin_unlock(&GlobalMid_Lock);
+                       spin_unlock(&cifs_oplock_lock);
                        DeleteOplockQEntry(oplock_item);
                        /* can not grab inode sem here since it would
                                deadlock when oplock received on delete
@@ -1055,7 +1055,7 @@ init_cifs(void)
        int rc = 0;
        cifs_proc_init();
        INIT_LIST_HEAD(&cifs_tcp_ses_list);
-       INIT_LIST_HEAD(&GlobalOplock_Q);
+       INIT_LIST_HEAD(&cifs_oplock_list);
 #ifdef CONFIG_CIFS_EXPERIMENTAL
        INIT_LIST_HEAD(&GlobalDnotifyReqList);
        INIT_LIST_HEAD(&GlobalDnotifyRsp_Q);
@@ -1084,6 +1084,7 @@ init_cifs(void)
        rwlock_init(&GlobalSMBSeslock);
        rwlock_init(&cifs_tcp_ses_lock);
        spin_lock_init(&GlobalMid_Lock);
+       spin_lock_init(&cifs_oplock_lock);
 
        if (cifs_max_pending < 2) {
                cifs_max_pending = 2;

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 6084d63..f100399 100644 (file)
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -656,7 +656,11 @@ GLOBAL_EXTERN rwlock_t             cifs_tcp_ses_lock;
  */
 GLOBAL_EXTERN rwlock_t GlobalSMBSeslock;
 
-GLOBAL_EXTERN struct list_head GlobalOplock_Q;
+/* Global list of oplocks */
+GLOBAL_EXTERN struct list_head cifs_oplock_list;
+
+/* Protects the cifs_oplock_list */
+GLOBAL_EXTERN spinlock_t cifs_oplock_lock;
 
 /* Outstanding dir notify requests */
 GLOBAL_EXTERN struct list_head GlobalDnotifyReqList;

diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 0ad3e2d..1da4ab2 100644 (file)
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -119,20 +119,19 @@ AllocOplockQEntry(struct inode *pinode, __u16 fid, struct cifsTconInfo *tcon)
                temp->pinode = pinode;
                temp->tcon = tcon;
                temp->netfid = fid;
-               spin_lock(&GlobalMid_Lock);
-               list_add_tail(&temp->qhead, &GlobalOplock_Q);
-               spin_unlock(&GlobalMid_Lock);
+               spin_lock(&cifs_oplock_lock);
+               list_add_tail(&temp->qhead, &cifs_oplock_list);
+               spin_unlock(&cifs_oplock_lock);
        }
        return temp;
-
 }
 
 void DeleteOplockQEntry(struct oplock_q_entry *oplockEntry)
 {
-       spin_lock(&GlobalMid_Lock);
+       spin_lock(&cifs_oplock_lock);
     /* should we check if list empty first? */
        list_del(&oplockEntry->qhead);
-       spin_unlock(&GlobalMid_Lock);
+       spin_unlock(&cifs_oplock_lock);
        kmem_cache_free(cifs_oplock_cachep, oplockEntry);
 }
 
@@ -144,14 +143,14 @@ void DeleteTconOplockQEntries(struct cifsTconInfo *tcon)
        if (tcon == NULL)
                return;
 
-       spin_lock(&GlobalMid_Lock);
-       list_for_each_entry(temp, &GlobalOplock_Q, qhead) {
+       spin_lock(&cifs_oplock_lock);
+       list_for_each_entry(temp, &cifs_oplock_list, qhead) {
                if ((temp->tcon) && (temp->tcon == tcon)) {
                        list_del(&temp->qhead);
                        kmem_cache_free(cifs_oplock_cachep, temp);
                }
        }
-       spin_unlock(&GlobalMid_Lock);
+       spin_unlock(&cifs_oplock_lock);
 }
 
 static int