提交 1a8322b2 编写于 作者: M Marc Eshel 提交者: J. Bruce Fields

lockd: add code to handle deferred lock requests

Rewrite nlmsvc_lock() to use the asynchronous interface.

As with testlock, we answer nlm requests in nlmsvc_lock by first looking up
the block and then using the results we find in the block if B_QUEUED is
set, and calling vfs_lock_file() otherwise.

If this a new lock request and we get -EINPROGRESS return on a non-blocking
request then we defer the request.

Also modify nlmsvc_unlock() to call the filesystem method if appropriate.
Signed-off-by: NMarc Eshel <eshel@almaden.ibm.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
上级 f8120480
......@@ -145,6 +145,8 @@ nlm4svc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
/* Now try to lock the file */
resp->status = nlmsvc_lock(rqstp, file, &argp->lock,
argp->block, &argp->cookie);
if (resp->status == nlm_drop_reply)
return rpc_drop_reply;
dprintk("lockd: LOCK status %d\n", ntohl(resp->status));
nlm_release_host(host);
......
......@@ -393,17 +393,43 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file,
} else
lock->fl.fl_flags &= ~FL_SLEEP;
error = posix_lock_file(file->f_file, &lock->fl, NULL);
lock->fl.fl_flags &= ~FL_SLEEP;
if (block->b_flags & B_QUEUED) {
dprintk("lockd: nlmsvc_lock deferred block %p flags %d\n",
block, block->b_flags);
if (block->b_granted) {
nlmsvc_unlink_block(block);
ret = nlm_granted;
goto out;
}
if (block->b_flags & B_TIMED_OUT) {
nlmsvc_unlink_block(block);
ret = nlm_lck_denied;
goto out;
}
ret = nlm_drop_reply;
goto out;
}
dprintk("lockd: posix_lock_file returned %d\n", error);
if (!wait)
lock->fl.fl_flags &= ~FL_SLEEP;
error = vfs_lock_file(file->f_file, F_SETLK, &lock->fl, NULL);
lock->fl.fl_flags &= ~FL_SLEEP;
dprintk("lockd: vfs_lock_file returned %d\n", error);
switch(error) {
case 0:
ret = nlm_granted;
goto out;
case -EAGAIN:
ret = nlm_lck_denied;
break;
case -EINPROGRESS:
if (wait)
break;
/* Filesystem lock operation is in progress
Add it to the queue waiting for callback */
ret = nlmsvc_defer_lock_rqst(rqstp, block);
goto out;
case -EDEADLK:
ret = nlm_deadlock;
goto out;
......@@ -535,7 +561,7 @@ nlmsvc_unlock(struct nlm_file *file, struct nlm_lock *lock)
nlmsvc_cancel_blocked(file, lock);
lock->fl.fl_type = F_UNLCK;
error = posix_lock_file(file->f_file, &lock->fl, NULL);
error = vfs_lock_file(file->f_file, F_SETLK, &lock->fl, NULL);
return (error < 0)? nlm_lck_denied_nolocks : nlm_granted;
}
......@@ -564,6 +590,8 @@ nlmsvc_cancel_blocked(struct nlm_file *file, struct nlm_lock *lock)
block = nlmsvc_lookup_block(file, lock);
mutex_unlock(&file->f_mutex);
if (block != NULL) {
vfs_cancel_lock(block->b_file->f_file,
&block->b_call->a_args.lock.fl);
status = nlmsvc_unlink_block(block);
nlmsvc_release_block(block);
}
......@@ -697,14 +725,15 @@ nlmsvc_grant_blocked(struct nlm_block *block)
/* Try the lock operation again */
lock->fl.fl_flags |= FL_SLEEP;
error = posix_lock_file(file->f_file, &lock->fl, NULL);
error = vfs_lock_file(file->f_file, F_SETLK, &lock->fl, NULL);
lock->fl.fl_flags &= ~FL_SLEEP;
switch (error) {
case 0:
break;
case -EAGAIN:
dprintk("lockd: lock still blocked\n");
case -EINPROGRESS:
dprintk("lockd: lock still blocked error %d\n", error);
nlmsvc_insert_block(block, NLM_NEVER);
nlmsvc_release_block(block);
return;
......
......@@ -175,6 +175,8 @@ nlmsvc_proc_lock(struct svc_rqst *rqstp, struct nlm_args *argp,
/* Now try to lock the file */
resp->status = cast_status(nlmsvc_lock(rqstp, file, &argp->lock,
argp->block, &argp->cookie));
if (resp->status == nlm_drop_reply)
return rpc_drop_reply;
dprintk("lockd: LOCK status %d\n", ntohl(resp->status));
nlm_release_host(host);
......
......@@ -182,7 +182,7 @@ nlm_traverse_locks(struct nlm_host *host, struct nlm_file *file,
lock.fl_type = F_UNLCK;
lock.fl_start = 0;
lock.fl_end = OFFSET_MAX;
if (posix_lock_file(file->f_file, &lock, NULL) < 0) {
if (vfs_lock_file(file->f_file, F_SETLK, &lock, NULL) < 0) {
printk("lockd: unlock failure in %s:%d\n",
__FILE__, __LINE__);
return 1;
......
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