lockd: Clean up of the server-side GRANTED code
[safe/jmp/linux-2.6] / fs / lockd / svclock.c
index e42f0cc..3c7dd95 100644 (file)
 #define nlm_deadlock   nlm_lck_denied
 #endif
 
+static void nlmsvc_release_block(struct nlm_block *block);
 static void    nlmsvc_insert_block(struct nlm_block *block, unsigned long);
 static int     nlmsvc_remove_block(struct nlm_block *block);
 
+static int nlmsvc_setgrantargs(struct nlm_rqst *call, struct nlm_lock *lock);
+static void nlmsvc_freegrantargs(struct nlm_rqst *call);
 static const struct rpc_call_ops nlmsvc_grant_ops;
 
 /*
@@ -58,6 +61,7 @@ nlmsvc_insert_block(struct nlm_block *block, unsigned long when)
        struct nlm_block **bp, *b;
 
        dprintk("lockd: nlmsvc_insert_block(%p, %ld)\n", block, when);
+       kref_get(&block->b_count);
        if (block->b_queued)
                nlmsvc_remove_block(block);
        bp = &nlm_blocked;
@@ -90,6 +94,7 @@ nlmsvc_remove_block(struct nlm_block *block)
                if (b == block) {
                        *bp = block->b_next;
                        block->b_queued = 0;
+                       nlmsvc_release_block(block);
                        return 1;
                }
        }
@@ -123,6 +128,7 @@ nlmsvc_lookup_block(struct nlm_file *file, struct nlm_lock *lock, int remove)
                                *head = block->b_next;
                                block->b_queued = 0;
                        }
+                       kref_get(&block->b_count);
                        return block;
                }
        }
@@ -155,6 +161,8 @@ nlmsvc_find_block(struct nlm_cookie *cookie,  struct sockaddr_in *sin)
                        break;
        }
 
+       if (block != NULL)
+               kref_get(&block->b_count);
        return block;
 }
 
@@ -188,11 +196,13 @@ nlmsvc_create_block(struct svc_rqst *rqstp, struct nlm_file *file,
        memset(block, 0, sizeof(*block));
        locks_init_lock(&block->b_call.a_args.lock.fl);
        locks_init_lock(&block->b_call.a_res.lock.fl);
+       kref_init(&block->b_count);
 
-       if (!nlmclnt_setgrantargs(&block->b_call, lock))
+       if (!nlmsvc_setgrantargs(&block->b_call, lock))
                goto failed_free;
 
        /* Set notifier function for VFS, and init args */
+       block->b_call.a_args.lock.fl.fl_flags |= FL_SLEEP;
        block->b_call.a_args.lock.fl.fl_lmops = &nlmsvc_lock_operations;
        block->b_call.a_args.cookie = *cookie;  /* see above */
 
@@ -227,32 +237,24 @@ failed:
  * It is the caller's responsibility to check whether the file
  * can be closed hereafter.
  */
-static void
-nlmsvc_delete_block(struct nlm_block *block, int unlock)
+static int nlmsvc_unlink_block(struct nlm_block *block)
 {
-       struct file_lock        *fl = &block->b_call.a_args.lock.fl;
-       struct nlm_file         *file = block->b_file;
-       struct nlm_block        **bp;
-
-       dprintk("lockd: deleting block %p...\n", block);
+       int status;
+       dprintk("lockd: unlinking block %p...\n", block);
 
        /* Remove block from list */
+       status = posix_unblock_lock(block->b_file->f_file, &block->b_call.a_args.lock.fl);
        nlmsvc_remove_block(block);
-       if (fl->fl_next)
-               posix_unblock_lock(file->f_file, fl);
-       if (unlock) {
-               fl->fl_type = F_UNLCK;
-               posix_lock_file(file->f_file, fl);
-               block->b_granted = 0;
-       }
+       return status;
+}
 
-       /* If the block is in the middle of a GRANT callback,
-        * don't kill it yet. */
-       if (block->b_incall) {
-               nlmsvc_insert_block(block, NLM_NEVER);
-               block->b_done = 1;
-               return;
-       }
+static void nlmsvc_free_block(struct kref *kref)
+{
+       struct nlm_block *block = container_of(kref, struct nlm_block, b_count);
+       struct nlm_file         *file = block->b_file;
+       struct nlm_block        **bp;
+
+       dprintk("lockd: freeing block %p...\n", block);
 
        /* Remove block from file's list of blocks */
        for (bp = &file->f_blocks; *bp; bp = &(*bp)->b_fnext) {
@@ -264,10 +266,16 @@ nlmsvc_delete_block(struct nlm_block *block, int unlock)
 
        if (block->b_host)
                nlm_release_host(block->b_host);
-       nlmclnt_freegrantargs(&block->b_call);
+       nlmsvc_freegrantargs(&block->b_call);
        kfree(block);
 }
 
+static void nlmsvc_release_block(struct nlm_block *block)
+{
+       if (block != NULL)
+               kref_put(&block->b_count, nlmsvc_free_block);
+}
+
 /*
  * Loop over all blocks and perform the action specified.
  * (NLM_ACT_CHECK handled by nlmsvc_inspect_file).
@@ -276,6 +284,7 @@ int
 nlmsvc_traverse_blocks(struct nlm_host *host, struct nlm_file *file, int action)
 {
        struct nlm_block        *block, *next;
+       /* XXX: Will everything get cleaned up if we don't unlock here? */
 
        down(&file->f_sema);
        for (block = file->f_blocks; block; block = next) {
@@ -284,7 +293,7 @@ nlmsvc_traverse_blocks(struct nlm_host *host, struct nlm_file *file, int action)
                        block->b_host->h_inuse = 1;
                else if (action == NLM_ACT_UNLOCK) {
                        if (host == NULL || host == block->b_host)
-                               nlmsvc_delete_block(block, 1);
+                               nlmsvc_unlink_block(block);
                }
        }
        up(&file->f_sema);
@@ -292,6 +301,49 @@ nlmsvc_traverse_blocks(struct nlm_host *host, struct nlm_file *file, int action)
 }
 
 /*
+ * Initialize arguments for GRANTED call. The nlm_rqst structure
+ * has been cleared already.
+ */
+static int nlmsvc_setgrantargs(struct nlm_rqst *call, struct nlm_lock *lock)
+{
+       locks_copy_lock(&call->a_args.lock.fl, &lock->fl);
+       memcpy(&call->a_args.lock.fh, &lock->fh, sizeof(call->a_args.lock.fh));
+       call->a_args.lock.caller = system_utsname.nodename;
+       call->a_args.lock.oh.len = lock->oh.len;
+
+       /* set default data area */
+       call->a_args.lock.oh.data = call->a_owner;
+       call->a_args.lock.svid = lock->fl.fl_pid;
+
+       if (lock->oh.len > NLMCLNT_OHSIZE) {
+               void *data = kmalloc(lock->oh.len, GFP_KERNEL);
+               if (!data) {
+                       nlmsvc_freegrantargs(call);
+                       return 0;
+               }
+               call->a_args.lock.oh.data = (u8 *) data;
+       }
+
+       memcpy(call->a_args.lock.oh.data, lock->oh.data, lock->oh.len);
+       return 1;
+}
+
+static void nlmsvc_freegrantargs(struct nlm_rqst *call)
+{
+       struct file_lock *fl = &call->a_args.lock.fl;
+       /*
+        * Check whether we allocated memory for the owner.
+        */
+       if (call->a_args.lock.oh.data != (u8 *) call->a_owner) {
+               kfree(call->a_args.lock.oh.data);
+       }
+       if (fl->fl_ops && fl->fl_ops->fl_release_private)
+               fl->fl_ops->fl_release_private(fl);
+       if (fl->fl_lmops && fl->fl_lmops->fl_release_private)
+               fl->fl_lmops->fl_release_private(fl);
+}
+
+/*
  * Attempt to establish a lock, and if it can't be granted, block it
  * if required.
  */
@@ -299,9 +351,9 @@ u32
 nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file,
                        struct nlm_lock *lock, int wait, struct nlm_cookie *cookie)
 {
-       struct file_lock        *conflock;
-       struct nlm_block        *block;
+       struct nlm_block        *block, *newblock = NULL;
        int                     error;
+       u32                     ret;
 
        dprintk("lockd: nlmsvc_lock(%s/%ld, ty=%d, pi=%d, %Ld-%Ld, bl=%d)\n",
                                file->f_file->f_dentry->d_inode->i_sb->s_id,
@@ -312,69 +364,65 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file,
                                wait);
 
 
-       /* Get existing block (in case client is busy-waiting) */
-       block = nlmsvc_lookup_block(file, lock, 0);
-
-       lock->fl.fl_flags |= FL_LOCKD;
-
+       lock->fl.fl_flags &= ~FL_SLEEP;
 again:
        /* Lock file against concurrent access */
        down(&file->f_sema);
+       /* Get existing block (in case client is busy-waiting) */
+       block = nlmsvc_lookup_block(file, lock, 0);
+       if (block == NULL) {
+               if (newblock != NULL)
+                       lock = &newblock->b_call.a_args.lock;
+       } else
+               lock = &block->b_call.a_args.lock;
 
-       if (!(conflock = posix_test_lock(file->f_file, &lock->fl))) {
-               error = posix_lock_file(file->f_file, &lock->fl);
+       error = posix_lock_file(file->f_file, &lock->fl);
+       lock->fl.fl_flags &= ~FL_SLEEP;
 
-               if (block)
-                       nlmsvc_delete_block(block, 0);
-               up(&file->f_sema);
+       dprintk("lockd: posix_lock_file returned %d\n", error);
 
-               dprintk("lockd: posix_lock_file returned %d\n", -error);
-               switch(-error) {
+       switch(error) {
                case 0:
-                       return nlm_granted;
-               case EDEADLK:
-                       return nlm_deadlock;
-               case EAGAIN:
-                       return nlm_lck_denied;
+                       ret = nlm_granted;
+                       goto out;
+               case -EAGAIN:
+                       break;
+               case -EDEADLK:
+                       ret = nlm_deadlock;
+                       goto out;
                default:                        /* includes ENOLCK */
-                       return nlm_lck_denied_nolocks;
-               }
+                       ret = nlm_lck_denied_nolocks;
+                       goto out;
        }
 
-       if (!wait) {
-               up(&file->f_sema);
-               return nlm_lck_denied;
-       }
+       ret = nlm_lck_denied;
+       if (!wait)
+               goto out;
 
-       if (posix_locks_deadlock(&lock->fl, conflock)) {
-               up(&file->f_sema);
-               return nlm_deadlock;
-       }
+       ret = nlm_lck_blocked;
+       if (block != NULL)
+               goto out;
 
        /* If we don't have a block, create and initialize it. Then
         * retry because we may have slept in kmalloc. */
        /* We have to release f_sema as nlmsvc_create_block may try to
         * to claim it while doing host garbage collection */
-       if (block == NULL) {
+       if (newblock == NULL) {
                up(&file->f_sema);
                dprintk("lockd: blocking on this lock (allocating).\n");
-               if (!(block = nlmsvc_create_block(rqstp, file, lock, cookie)))
+               if (!(newblock = nlmsvc_create_block(rqstp, file, lock, cookie)))
                        return nlm_lck_denied_nolocks;
                goto again;
        }
 
        /* Append to list of blocked */
-       nlmsvc_insert_block(block, NLM_NEVER);
-
-       if (list_empty(&block->b_call.a_args.lock.fl.fl_block)) {
-               /* Now add block to block list of the conflicting lock
-                  if we haven't done so. */
-               dprintk("lockd: blocking on this lock.\n");
-               posix_block_lock(conflock, &block->b_call.a_args.lock.fl);
-       }
-
+       nlmsvc_insert_block(newblock, NLM_NEVER);
+out:
        up(&file->f_sema);
-       return nlm_lck_blocked;
+       nlmsvc_release_block(newblock);
+       nlmsvc_release_block(block);
+       dprintk("lockd: nlmsvc_lock returned %u\n", ret);
+       return ret;
 }
 
 /*
@@ -384,8 +432,6 @@ u32
 nlmsvc_testlock(struct nlm_file *file, struct nlm_lock *lock,
                                       struct nlm_lock *conflock)
 {
-       struct file_lock        *fl;
-
        dprintk("lockd: nlmsvc_testlock(%s/%ld, ty=%d, %Ld-%Ld)\n",
                                file->f_file->f_dentry->d_inode->i_sb->s_id,
                                file->f_file->f_dentry->d_inode->i_ino,
@@ -393,13 +439,14 @@ nlmsvc_testlock(struct nlm_file *file, struct nlm_lock *lock,
                                (long long)lock->fl.fl_start,
                                (long long)lock->fl.fl_end);
 
-       if ((fl = posix_test_lock(file->f_file, &lock->fl)) != NULL) {
+       if (posix_test_lock(file->f_file, &lock->fl, &conflock->fl)) {
                dprintk("lockd: conflicting lock(ty=%d, %Ld-%Ld)\n",
-                               fl->fl_type, (long long)fl->fl_start,
-                               (long long)fl->fl_end);
+                               conflock->fl.fl_type,
+                               (long long)conflock->fl.fl_start,
+                               (long long)conflock->fl.fl_end);
                conflock->caller = "somehost";  /* FIXME */
                conflock->oh.len = 0;           /* don't return OH info */
-               conflock->fl = *fl;
+               conflock->svid = conflock->fl.fl_pid;
                return nlm_lck_denied;
        }
 
@@ -445,6 +492,7 @@ u32
 nlmsvc_cancel_blocked(struct nlm_file *file, struct nlm_lock *lock)
 {
        struct nlm_block        *block;
+       int status = 0;
 
        dprintk("lockd: nlmsvc_cancel(%s/%ld, pi=%d, %Ld-%Ld)\n",
                                file->f_file->f_dentry->d_inode->i_sb->s_id,
@@ -454,10 +502,12 @@ nlmsvc_cancel_blocked(struct nlm_file *file, struct nlm_lock *lock)
                                (long long)lock->fl.fl_end);
 
        down(&file->f_sema);
-       if ((block = nlmsvc_lookup_block(file, lock, 1)) != NULL)
-               nlmsvc_delete_block(block, 1);
+       if ((block = nlmsvc_lookup_block(file, lock, 1)) != NULL) {
+               status = nlmsvc_unlink_block(block);
+               nlmsvc_release_block(block);
+       }
        up(&file->f_sema);
-       return nlm_granted;
+       return status ? nlm_lck_denied : nlm_granted;
 }
 
 /*
@@ -510,7 +560,6 @@ nlmsvc_grant_blocked(struct nlm_block *block)
 {
        struct nlm_file         *file = block->b_file;
        struct nlm_lock         *lock = &block->b_call.a_args.lock;
-       struct file_lock        *conflock;
        int                     error;
 
        dprintk("lockd: grant blocked lock %p\n", block);
@@ -519,7 +568,7 @@ nlmsvc_grant_blocked(struct nlm_block *block)
        down(&file->f_sema);
 
        /* Unlink block request from list */
-       nlmsvc_remove_block(block);
+       nlmsvc_unlink_block(block);
 
        /* If b_granted is true this means we've been here before.
         * Just retry the grant callback, possibly refreshing the RPC
@@ -530,41 +579,38 @@ nlmsvc_grant_blocked(struct nlm_block *block)
        }
 
        /* Try the lock operation again */
-       if ((conflock = posix_test_lock(file->f_file, &lock->fl)) != NULL) {
-               /* Bummer, we blocked again */
+       lock->fl.fl_flags |= FL_SLEEP;
+       error = posix_lock_file(file->f_file, &lock->fl);
+       lock->fl.fl_flags &= ~FL_SLEEP;
+
+       switch (error) {
+       case 0:
+               break;
+       case -EAGAIN:
                dprintk("lockd: lock still blocked\n");
                nlmsvc_insert_block(block, NLM_NEVER);
-               posix_block_lock(conflock, &lock->fl);
-               up(&file->f_sema);
-               return;
-       }
-
-       /* Alright, no conflicting lock. Now lock it for real. If the
-        * following yields an error, this is most probably due to low
-        * memory. Retry the lock in a few seconds.
-        */
-       if ((error = posix_lock_file(file->f_file, &lock->fl)) < 0) {
+               goto out_unlock;
+       default:
                printk(KERN_WARNING "lockd: unexpected error %d in %s!\n",
                                -error, __FUNCTION__);
                nlmsvc_insert_block(block, 10 * HZ);
-               up(&file->f_sema);
-               return;
+               goto out_unlock;
        }
 
 callback:
        /* Lock was granted by VFS. */
        dprintk("lockd: GRANTing blocked lock.\n");
        block->b_granted = 1;
-       block->b_incall  = 1;
 
        /* Schedule next grant callback in 30 seconds */
        nlmsvc_insert_block(block, 30 * HZ);
 
        /* Call the client */
-       nlm_get_host(block->b_call.a_host);
+       kref_get(&block->b_count);
        if (nlmsvc_async_call(&block->b_call, NLMPROC_GRANTED_MSG,
                                                &nlmsvc_grant_ops) < 0)
-               nlm_release_host(block->b_call.a_host);
+               nlmsvc_release_block(block);
+out_unlock:
        up(&file->f_sema);
 }
 
@@ -579,20 +625,10 @@ callback:
 static void nlmsvc_grant_callback(struct rpc_task *task, void *data)
 {
        struct nlm_rqst         *call = data;
-       struct nlm_block        *block;
+       struct nlm_block        *block = container_of(call, struct nlm_block, b_call);
        unsigned long           timeout;
-       struct sockaddr_in      *peer_addr = RPC_PEERADDR(task->tk_client);
 
        dprintk("lockd: GRANT_MSG RPC callback\n");
-       dprintk("callback: looking for cookie %s, host (%u.%u.%u.%u)\n",
-               nlmdbg_cookie2a(&call->a_args.cookie),
-               NIPQUAD(peer_addr->sin_addr.s_addr));
-       if (!(block = nlmsvc_find_block(&call->a_args.cookie, peer_addr))) {
-               dprintk("lockd: no block for cookie %s, host (%u.%u.%u.%u)\n",
-                       nlmdbg_cookie2a(&call->a_args.cookie),
-                       NIPQUAD(peer_addr->sin_addr.s_addr));
-               return;
-       }
 
        /* Technically, we should down the file semaphore here. Since we
         * move the block towards the head of the queue only, no harm
@@ -609,13 +645,16 @@ static void nlmsvc_grant_callback(struct rpc_task *task, void *data)
        }
        nlmsvc_insert_block(block, timeout);
        svc_wake_up(block->b_daemon);
-       block->b_incall = 0;
+}
 
-       nlm_release_host(call->a_host);
+void nlmsvc_grant_release(void *data)
+{
+       nlmsvc_release_block(data);
 }
 
 static const struct rpc_call_ops nlmsvc_grant_ops = {
        .rpc_call_done = nlmsvc_grant_callback,
+       .rpc_release = nlmsvc_grant_release,
 };
 
 /*
@@ -637,23 +676,19 @@ nlmsvc_grant_reply(struct svc_rqst *rqstp, struct nlm_cookie *cookie, u32 status
 
        file->f_count++;
        down(&file->f_sema);
-       block = nlmsvc_find_block(cookie, &rqstp->rq_addr);
        if (block) {
                if (status == NLM_LCK_DENIED_GRACE_PERIOD) {
                        /* Try again in a couple of seconds */
                        nlmsvc_insert_block(block, 10 * HZ);
-                       up(&file->f_sema);
                } else {
                        /* Lock is now held by client, or has been rejected.
                         * In both cases, the block should be removed. */
-                       up(&file->f_sema);
-                       if (status == NLM_LCK_GRANTED)
-                               nlmsvc_delete_block(block, 0);
-                       else
-                               nlmsvc_delete_block(block, 1);
+                       nlmsvc_unlink_block(block);
                }
        }
+       up(&file->f_sema);
        nlm_release_file(file);
+       nlmsvc_release_block(block);
 }
 
 /*
@@ -676,10 +711,12 @@ nlmsvc_retry_blocked(void)
                        break;
                dprintk("nlmsvc_retry_blocked(%p, when=%ld, done=%d)\n",
                        block, block->b_when, block->b_done);
+               kref_get(&block->b_count);
                if (block->b_done)
-                       nlmsvc_delete_block(block, 0);
+                       nlmsvc_unlink_block(block);
                else
                        nlmsvc_grant_blocked(block);
+               nlmsvc_release_block(block);
        }
 
        if ((block = nlm_blocked) && block->b_when != NLM_NEVER)