korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-11 04:18:39 +08:00
Code Issues Packages Projects Releases Wiki Activity

lockd: handle test_lock deferrals

Browse Source 
Rewrite nlmsvc_testlock() to use the new asynchronous interface: instead of
immediately doing a posix_test_lock(), we first look for a matching block.
If the subsequent test_lock returns anything other than -EINPROGRESS, we
then remove the block we've found and return the results.

If it returns -EINPROGRESS, then we defer the lock request.

In the case where the block we find in the first step has B_QUEUED set,
we bypass the vfs_test_lock entirely, instead using the block to decide how
to respond:
	with nlm_lck_denied if B_TIMED_OUT is set.
	with nlm_granted if B_GOT_CALLBACK is set.
	by dropping if neither B_TIMED_OUT nor B_GOT_CALLBACK is set

Signed-off-by: Marc Eshel <eshel@almaden.ibm.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
This commit is contained in:
Marc Eshel 2006-11-28 16:27:06 -05:00 committed by J. Bruce Fields
parent 85f3f1b3f7
commit 5ea0d75037
3 changed files with 73 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
fs/lockd/svc4proc.c
View File

@ -100,6 +100,8 @@ nlm4svc_proc_test(struct svc_rqst *rqstp, struct nlm_args *argp,
/* Now check for conflicting locks */
resp->status = nlmsvc_testlock(rqstp, file, &argp->lock, &resp->lock, &resp->cookie);
if (resp->status == nlm_drop_reply)
return rpc_drop_reply;
dprintk("lockd: TEST4 status %d\n", ntohl(resp->status));
nlm_release_host(host);

84
fs/lockd/svclock.c
View File

@ -173,7 +173,7 @@ found:
*/
static inline struct nlm_block *
nlmsvc_create_block(struct svc_rqst *rqstp, struct nlm_file *file,
struct nlm_lock *lock, struct nlm_cookie *cookie)
struct nlm_lock *lock, struct nlm_cookie *cookie)
{
struct nlm_block *block;
struct nlm_host *host;
@ -210,6 +210,7 @@ nlmsvc_create_block(struct svc_rqst *rqstp, struct nlm_file *file,
block->b_daemon = rqstp->rq_server;
block->b_host = host;
block->b_file = file;
block->b_fl = NULL;
file->f_count++;
/* Add to file's list of blocks */
@ -446,6 +447,10 @@ nlmsvc_testlock(struct svc_rqst *rqstp, struct nlm_file *file,
struct nlm_lock *lock, struct nlm_lock *conflock,
struct nlm_cookie *cookie)
{
struct nlm_block *block = NULL;
int error;
__be32 ret;
dprintk("lockd: nlmsvc_testlock(%s/%ld, ty=%d, %Ld-%Ld)\n",
file->f_file->f_path.dentry->d_inode->i_sb->s_id,
file->f_file->f_path.dentry->d_inode->i_ino,
@ -453,22 +458,70 @@ nlmsvc_testlock(struct svc_rqst *rqstp, struct nlm_file *file,
(long long)lock->fl.fl_start,
(long long)lock->fl.fl_end);
if (posix_test_lock(file->f_file, &lock->fl)) {
dprintk("lockd: conflicting lock(ty=%d, %Ld-%Ld)\n",
lock->fl.fl_type,
(long long)lock->fl.fl_start,
(long long)lock->fl.fl_end);
conflock->caller = "somehost"; /* FIXME */
conflock->len = strlen(conflock->caller);
conflock->oh.len = 0; /* don't return OH info */
conflock->svid = lock->fl.fl_pid;
conflock->fl.fl_type = lock->fl.fl_type;
conflock->fl.fl_start = lock->fl.fl_start;
conflock->fl.fl_end = lock->fl.fl_end;
return nlm_lck_denied;
/* Get existing block (in case client is busy-waiting) */
block = nlmsvc_lookup_block(file, lock);
if (block == NULL) {
struct file_lock *conf = kzalloc(sizeof(*conf), GFP_KERNEL);
if (conf == NULL)
return nlm_granted;
block = nlmsvc_create_block(rqstp, file, lock, cookie);
if (block == NULL) {
kfree(conf);
return nlm_granted;
}
block->b_fl = conf;
}
if (block->b_flags & B_QUEUED) {
dprintk("lockd: nlmsvc_testlock deferred block %p flags %d fl %p\n",
block, block->b_flags, block->b_fl);
if (block->b_flags & B_TIMED_OUT) {
nlmsvc_unlink_block(block);
return nlm_lck_denied;
}
if (block->b_flags & B_GOT_CALLBACK) {
if (block->b_fl != NULL
&& block->b_fl->fl_type != F_UNLCK) {
lock->fl = *block->b_fl;
goto conf_lock;
}
else {
nlmsvc_unlink_block(block);
return nlm_granted;
}
}
return nlm_drop_reply;
}
return nlm_granted;
error = vfs_test_lock(file->f_file, &lock->fl);
if (error == -EINPROGRESS)
return nlmsvc_defer_lock_rqst(rqstp, block);
if (error) {
ret = nlm_lck_denied_nolocks;
goto out;
}
if (lock->fl.fl_type == F_UNLCK) {
ret = nlm_granted;
goto out;
}
conf_lock:
dprintk("lockd: conflicting lock(ty=%d, %Ld-%Ld)\n",
lock->fl.fl_type, (long long)lock->fl.fl_start,
(long long)lock->fl.fl_end);
conflock->caller = "somehost"; /* FIXME */
conflock->len = strlen(conflock->caller);
conflock->oh.len = 0; /* don't return OH info */
conflock->svid = lock->fl.fl_pid;
conflock->fl.fl_type = lock->fl.fl_type;
conflock->fl.fl_start = lock->fl.fl_start;
conflock->fl.fl_end = lock->fl.fl_end;
ret = nlm_lck_denied;
out:
if (block)
nlmsvc_release_block(block);
return ret;
}
/*
@ -549,7 +602,6 @@ nlmsvc_update_deferred_block(struct nlm_block *block, struct file_lock *conf,
else
block->b_flags |= B_TIMED_OUT;
if (conf) {
block->b_fl = kzalloc(sizeof(struct file_lock), GFP_KERNEL);
if (block->b_fl)
locks_copy_lock(block->b_fl, conf);
}

3
fs/lockd/svcproc.c
View File

@ -33,6 +33,7 @@ cast_to_nlm(__be32 status, u32 vers)
case nlm_lck_denied_nolocks:
case nlm_lck_blocked:
case nlm_lck_denied_grace_period:
case nlm_drop_reply:
break;
case nlm4_deadlock:
status = nlm_lck_denied;
@ -128,6 +129,8 @@ nlmsvc_proc_test(struct svc_rqst *rqstp, struct nlm_args *argp,
/* Now check for conflicting locks */
resp->status = cast_status(nlmsvc_testlock(rqstp, file, &argp->lock, &resp->lock, &resp->cookie));
if (resp->status == nlm_drop_reply)
return rpc_drop_reply;
dprintk("lockd: TEST status %d vers %d\n",
ntohl(resp->status), rqstp->rq_vers);