From 900083183959107159f962b83b3b439d53796499 Mon Sep 17 00:00:00 2001 From: David Teigland Date: Fri, 5 Apr 2013 10:57:15 +0100 Subject: dlm: avoid unnecessary posix unlock When the kernel clears flocks/plocks during close, it calls posix unlock when there are flocks but no posix locks. Without this patch, that unnecessary posix unlock is passed to userland (dlm_controld), across the cluster, and back to the kernel. This can create a lot of plock activity, even when no posix locks had been used. This patch copies the nfs approach, and skips the full posix unlock if there is no plock found during the vfs unlock phase. Signed-off-by: David Teigland --- fs/dlm/plock.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) (limited to 'fs/dlm') diff --git a/fs/dlm/plock.c b/fs/dlm/plock.c index 01fd5c11a7fb..f704458ea5f5 100644 --- a/fs/dlm/plock.c +++ b/fs/dlm/plock.c @@ -247,6 +247,7 @@ int dlm_posix_unlock(dlm_lockspace_t *lockspace, u64 number, struct file *file, struct dlm_ls *ls; struct plock_op *op; int rv; + unsigned char fl_flags = fl->fl_flags; ls = dlm_find_lockspace_local(lockspace); if (!ls) @@ -258,9 +259,18 @@ int dlm_posix_unlock(dlm_lockspace_t *lockspace, u64 number, struct file *file, goto out; } - if (posix_lock_file_wait(file, fl) < 0) - log_error(ls, "dlm_posix_unlock: vfs unlock error %llx", - (unsigned long long)number); + /* cause the vfs unlock to return ENOENT if lock is not found */ + fl->fl_flags |= FL_EXISTS; + + rv = posix_lock_file_wait(file, fl); + if (rv == -ENOENT) { + rv = 0; + goto out_free; + } + if (rv < 0) { + log_error(ls, "dlm_posix_unlock: vfs unlock error %d %llx", + rv, (unsigned long long)number); + } op->info.optype = DLM_PLOCK_OP_UNLOCK; op->info.pid = fl->fl_pid; @@ -296,9 +306,11 @@ int dlm_posix_unlock(dlm_lockspace_t *lockspace, u64 number, struct file *file, if (rv == -ENOENT) rv = 0; +out_free: kfree(op); out: dlm_put_lockspace(ls); + fl->fl_flags = fl_flags; return rv; } EXPORT_SYMBOL_GPL(dlm_posix_unlock); -- cgit v1.2.3