From 9b646972467fb5fdc677f9e4251875db20bdbb64 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 20 Jul 2010 22:09:02 +0200 Subject: cifs: use workqueue instead of slow-work Workqueue can now handle high concurrency. Use system_nrt_wq instead of slow-work. * Updated is_valid_oplock_break() to not call cifs_oplock_break_put() as advised by Steve French. It might cause deadlock. Instead, reference is increased after queueing succeeded and cifs_oplock_break() briefly grabs GlobalSMBSeslock before putting the cfile to make sure it doesn't put before the matching get is finished. * Anton Blanchard reported that cifs conversion was using now gone system_single_wq. Use system_nrt_wq which provides non-reentrance guarantee which is enough and much better. Signed-off-by: Tejun Heo Acked-by: Steve French Cc: Anton Blanchard --- fs/cifs/misc.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) (limited to 'fs/cifs/misc.c') diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c index 1394aa37f26..3ccadc1326d 100644 --- a/fs/cifs/misc.c +++ b/fs/cifs/misc.c @@ -498,7 +498,6 @@ is_valid_oplock_break(struct smb_hdr *buf, struct TCP_Server_Info *srv) struct cifsTconInfo *tcon; struct cifsInodeInfo *pCifsInode; struct cifsFileInfo *netfile; - int rc; cFYI(1, "Checking for oplock break or dnotify response"); if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) && @@ -583,13 +582,18 @@ is_valid_oplock_break(struct smb_hdr *buf, struct TCP_Server_Info *srv) pCifsInode->clientCanCacheAll = false; if (pSMB->OplockLevel == 0) pCifsInode->clientCanCacheRead = false; - rc = slow_work_enqueue(&netfile->oplock_break); - if (rc) { - cERROR(1, "failed to enqueue oplock " - "break: %d\n", rc); - } else { - netfile->oplock_break_cancelled = false; - } + + /* + * cifs_oplock_break_put() can't be called + * from here. Get reference after queueing + * succeeded. cifs_oplock_break() will + * synchronize using GlobalSMSSeslock. + */ + if (queue_work(system_nrt_wq, + &netfile->oplock_break)) + cifs_oplock_break_get(netfile); + netfile->oplock_break_cancelled = false; + read_unlock(&GlobalSMBSeslock); read_unlock(&cifs_tcp_ses_lock); return true; -- cgit v1.2.3