From 5ea0d75037b93baa453b4d326c6319968fe91cea Mon Sep 17 00:00:00 2001 From: Marc Eshel Date: Tue, 28 Nov 2006 16:27:06 -0500 Subject: lockd: handle test_lock deferrals 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 Signed-off-by: J. Bruce Fields --- fs/lockd/svc4proc.c | 2 ++ fs/lockd/svclock.c | 84 +++++++++++++++++++++++++++++++++++++++++++---------- fs/lockd/svcproc.c | 3 ++ 3 files changed, 73 insertions(+), 16 deletions(-) (limited to 'fs/lockd') diff --git a/fs/lockd/svc4proc.c b/fs/lockd/svc4proc.c index a1bccad7ebd..205d8befbf1 100644 --- a/fs/lockd/svc4proc.c +++ b/fs/lockd/svc4proc.c @@ -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); diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c index 7ab2e60c51f..b7a8174fd1d 100644 --- a/fs/lockd/svclock.c +++ b/fs/lockd/svclock.c @@ -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; + } + + 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; } - return nlm_granted; +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); } diff --git a/fs/lockd/svcproc.c b/fs/lockd/svcproc.c index d13b827dfd3..40b5cf496b5 100644 --- a/fs/lockd/svcproc.c +++ b/fs/lockd/svcproc.c @@ -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); -- cgit v1.2.3