From: Marc Eshel <[email protected]> - unquoted
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_TOO_LATE is set.
with nlm_granted if B_GOT_CALLBACK is set.
by dropping if neither B_TOO_LATE nor B_GOT_CALLBACK is set
Signed-off-by: Marc Eshel <[email protected]>
Signed-off-by: J. Bruce Fields <[email protected]>
---
fs/lockd/svclock.c | 61 ++++++++++++++++++++++++++++++++++++++++++---------
1 files changed, 50 insertions(+), 11 deletions(-)
diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c
index 93f1bc8..91690e3 100644
--- a/fs/lockd/svclock.c
+++ b/fs/lockd/svclock.c
@@ -447,6 +447,9 @@ 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;
+
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,
@@ -454,19 +457,55 @@ 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, &conflock->fl)) {
- dprintk("lockd: conflicting lock(ty=%d, %Ld-%Ld)\n",
- conflock->fl.fl_type,
- (long long)conflock->fl.fl_start,
- (long long)conflock->fl.fl_end);
- conflock->caller = "somehost"; /* FIXME */
- conflock->len = strlen(conflock->caller);
- conflock->oh.len = 0; /* don't return OH info */
- conflock->svid = conflock->fl.fl_pid;
- return nlm_lck_denied;
+ /* Get existing block (in case client is busy-waiting) */
+ block = nlmsvc_lookup_block(file, lock);
+
+ if (block == NULL) {
+ block = nlmsvc_create_block(rqstp, file, lock, cookie);
+ if (block == NULL)
+ return nlm_granted;
+ }
+ 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_TOO_LATE) {
+ nlmsvc_unlink_block(block);
+ return nlm_lck_denied;
+ }
+ if (block->b_flags & B_GOT_CALLBACK) {
+ if (block->b_fl != NULL) {
+ conflock->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, &conflock->fl);
+ if (error == -EINPROGRESS)
+ return nlmsvc_defer_lock_rqst(rqstp, block);
+ if (error)
+ return nlm_lck_denied_nolocks;
+ if (conflock->fl.fl_type == F_UNLCK) {
+ nlmsvc_unlink_block(block);
+ return nlm_granted;
+ }
+
+conf_lock:
+ dprintk("lockd: conflicting lock(ty=%d, %Ld-%Ld)\n",
+ conflock->fl.fl_type, (long long)conflock->fl.fl_start,
+ (long long)conflock->fl.fl_end);
+ conflock->caller = "somehost"; /* FIXME */
+ conflock->len = strlen(conflock->caller);
+ conflock->oh.len = 0; /* don't return OH info */
+ conflock->svid = conflock->fl.fl_pid;
+ if (block)
+ nlmsvc_unlink_block(block);
+ return nlm_lck_denied;
}
/*
--
1.5.0.rc1.g72fe