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>
This commit is contained in:
Jeff Layton 2009-08-28 10:11:11 -04:00 committed by Steve French
parent 8e047d09ee
commit 1b49c55661
3 changed files with 20 additions and 16 deletions

View file

@ -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;

View file

@ -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;

View file

@ -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