Merge ../linux-2.6
[pandora-kernel.git] / fs / lockd / svclock.c
index d683dd0..c9d4197 100644 (file)
@@ -20,7 +20,6 @@
  * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
  */
 
-#include <linux/config.h>
 #include <linux/types.h>
 #include <linux/errno.h>
 #include <linux/kernel.h>
 #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 +60,7 @@ 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 +93,7 @@ nlmsvc_remove_block(struct nlm_block *block)
                if (b == block) {
                        *bp = block->b_next;
                        block->b_queued = 0;
+                       nlmsvc_release_block(block);
                        return 1;
                }
        }
@@ -98,11 +102,10 @@ nlmsvc_remove_block(struct nlm_block *block)
 }
 
 /*
- * Find a block for a given lock and optionally remove it from
- * the list.
+ * Find a block for a given lock
  */
 static struct nlm_block *
-nlmsvc_lookup_block(struct nlm_file *file, struct nlm_lock *lock, int remove)
+nlmsvc_lookup_block(struct nlm_file *file, struct nlm_lock *lock)
 {
        struct nlm_block        **head, *block;
        struct file_lock        *fl;
@@ -112,17 +115,14 @@ nlmsvc_lookup_block(struct nlm_file *file, struct nlm_lock *lock, int remove)
                                (long long)lock->fl.fl_start,
                                (long long)lock->fl.fl_end, lock->fl.fl_type);
        for (head = &nlm_blocked; (block = *head) != 0; head = &block->b_next) {
-               fl = &block->b_call.a_args.lock.fl;
+               fl = &block->b_call->a_args.lock.fl;
                dprintk("lockd: check f=%p pd=%d %Ld-%Ld ty=%d cookie=%s\n",
                                block->b_file, fl->fl_pid,
                                (long long)fl->fl_start,
                                (long long)fl->fl_end, fl->fl_type,
-                               nlmdbg_cookie2a(&block->b_call.a_args.cookie));
+                               nlmdbg_cookie2a(&block->b_call->a_args.cookie));
                if (block->b_file == file && nlm_compare_locks(fl, &lock->fl)) {
-                       if (remove) {
-                               *head = block->b_next;
-                               block->b_queued = 0;
-                       }
+                       kref_get(&block->b_count);
                        return block;
                }
        }
@@ -150,11 +150,13 @@ nlmsvc_find_block(struct nlm_cookie *cookie,  struct sockaddr_in *sin)
        for (block = nlm_blocked; block; block = block->b_next) {
                dprintk("cookie: head of blocked queue %p, block %p\n", 
                        nlm_blocked, block);
-               if (nlm_cookie_match(&block->b_call.a_args.cookie,cookie)
+               if (nlm_cookie_match(&block->b_call->a_args.cookie,cookie)
                                && nlm_cmp_addr(sin, &block->b_host->h_addr))
                        break;
        }
 
+       if (block != NULL)
+               kref_get(&block->b_count);
        return block;
 }
 
@@ -174,27 +176,30 @@ nlmsvc_create_block(struct svc_rqst *rqstp, struct nlm_file *file,
 {
        struct nlm_block        *block;
        struct nlm_host         *host;
-       struct nlm_rqst         *call;
+       struct nlm_rqst         *call = NULL;
 
        /* Create host handle for callback */
-       host = nlmclnt_lookup_host(&rqstp->rq_addr,
-                               rqstp->rq_prot, rqstp->rq_vers);
+       host = nlmsvc_lookup_host(rqstp);
        if (host == NULL)
                return NULL;
 
+       call = nlm_alloc_call(host);
+       if (call == NULL)
+               return NULL;
+
        /* Allocate memory for block, and initialize arguments */
-       if (!(block = (struct nlm_block *) kmalloc(sizeof(*block), GFP_KERNEL)))
+       block = kzalloc(sizeof(*block), GFP_KERNEL);
+       if (block == NULL)
                goto failed;
-       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(call, lock))
                goto failed_free;
 
        /* Set notifier function for VFS, and init args */
-       block->b_call.a_args.lock.fl.fl_lmops = &nlmsvc_lock_operations;
-       block->b_call.a_args.cookie = *cookie;  /* see above */
+       call->a_args.lock.fl.fl_flags |= FL_SLEEP;
+       call->a_args.lock.fl.fl_lmops = &nlmsvc_lock_operations;
+       call->a_args.cookie = *cookie;  /* see above */
 
        dprintk("lockd: created block %p...\n", block);
 
@@ -202,22 +207,23 @@ 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;
+       file->f_count++;
 
        /* Add to file's list of blocks */
        block->b_fnext  = file->f_blocks;
        file->f_blocks  = block;
 
        /* Set up RPC arguments for callback */
-       call = &block->b_call;
-       call->a_host    = host;
+       block->b_call = call;
        call->a_flags   = RPC_TASK_ASYNC;
+       call->a_block = block;
 
        return block;
 
 failed_free:
        kfree(block);
 failed:
-       nlm_release_host(host);
+       nlm_release_call(call);
        return NULL;
 }
 
@@ -227,29 +233,26 @@ failed:
  * It is the caller's responsibility to check whether the file
  * can be closed hereafter.
  */
-static int
-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;
-       int status = 0;
-
-       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 (unlock)
-               status = posix_unblock_lock(file->f_file, fl);
+       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 status;
-       }
+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);
 
+       down(&file->f_sema);
        /* Remove block from file's list of blocks */
        for (bp = &file->f_blocks; *bp; bp = &(*bp)->b_fnext) {
                if (*bp == block) {
@@ -257,36 +260,93 @@ nlmsvc_delete_block(struct nlm_block *block, int unlock)
                        break;
                }
        }
+       up(&file->f_sema);
 
-       if (block->b_host)
-               nlm_release_host(block->b_host);
-       nlmclnt_freegrantargs(&block->b_call);
+       nlmsvc_freegrantargs(block->b_call);
+       nlm_release_call(block->b_call);
+       nlm_release_file(block->b_file);
        kfree(block);
-       return status;
+}
+
+static void nlmsvc_release_block(struct nlm_block *block)
+{
+       if (block != NULL)
+               kref_put(&block->b_count, nlmsvc_free_block);
+}
+
+static void nlmsvc_act_mark(struct nlm_host *host, struct nlm_file *file)
+{
+       struct nlm_block *block;
+
+       down(&file->f_sema);
+       for (block = file->f_blocks; block != NULL; block = block->b_fnext)
+               block->b_host->h_inuse = 1;
+       up(&file->f_sema);
+}
+
+static void nlmsvc_act_unlock(struct nlm_host *host, struct nlm_file *file)
+{
+       struct nlm_block *block;
+
+restart:
+       down(&file->f_sema);
+       for (block = file->f_blocks; block != NULL; block = block->b_fnext) {
+               if (host != NULL && host != block->b_host)
+                       continue;
+               if (!block->b_queued)
+                       continue;
+               kref_get(&block->b_count);
+               up(&file->f_sema);
+               nlmsvc_unlink_block(block);
+               nlmsvc_release_block(block);
+               goto restart;
+       }
+       up(&file->f_sema);
 }
 
 /*
  * Loop over all blocks and perform the action specified.
  * (NLM_ACT_CHECK handled by nlmsvc_inspect_file).
  */
-int
+void
 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? */
+       if (action == NLM_ACT_MARK)
+               nlmsvc_act_mark(host, file);
+       else
+               nlmsvc_act_unlock(host, file);
+}
 
-       down(&file->f_sema);
-       for (block = file->f_blocks; block; block = next) {
-               next = block->b_fnext;
-               if (action == NLM_ACT_MARK)
-                       block->b_host->h_inuse = 1;
-               else if (action == NLM_ACT_UNLOCK) {
-                       if (host == NULL || host == block->b_host)
-                               nlmsvc_delete_block(block, 1);
-               }
+/*
+ * 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)
+                       return 0;
+               call->a_args.lock.oh.data = (u8 *) data;
        }
-       up(&file->f_sema);
-       return 0;
+
+       memcpy(call->a_args.lock.oh.data, lock->oh.data, lock->oh.len);
+       return 1;
+}
+
+static void nlmsvc_freegrantargs(struct nlm_rqst *call)
+{
+       if (call->a_args.lock.oh.data != call->a_owner)
+               kfree(call->a_args.lock.oh.data);
 }
 
 /*
@@ -297,7 +357,7 @@ u32
 nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file,
                        struct nlm_lock *lock, int wait, struct nlm_cookie *cookie)
 {
-       struct nlm_block        *block;
+       struct nlm_block        *block, *newblock = NULL;
        int                     error;
        u32                     ret;
 
@@ -310,61 +370,63 @@ 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);
+       if (block == NULL) {
+               if (newblock != NULL)
+                       lock = &newblock->b_call->a_args.lock;
+       } else
+               lock = &block->b_call->a_args.lock;
 
        error = posix_lock_file(file->f_file, &lock->fl);
+       lock->fl.fl_flags &= ~FL_SLEEP;
 
        dprintk("lockd: posix_lock_file returned %d\n", error);
 
-       if (error != -EAGAIN) {
-               if (block)
-                       nlmsvc_delete_block(block, 0);
-               up(&file->f_sema);
-
-               switch(-error) {
+       switch(error) {
                case 0:
                        ret = nlm_granted;
                        goto out;
-               case EDEADLK:
+               case -EAGAIN:
+                       break;
+               case -EDEADLK:
                        ret = nlm_deadlock;
                        goto out;
                default:                        /* includes ENOLCK */
                        ret = nlm_lck_denied_nolocks;
                        goto out;
-               }
        }
 
-       if (!wait) {
-               ret = nlm_lck_denied;
-               goto out_unlock;
-       }
+       ret = nlm_lck_denied;
+       if (!wait)
+               goto out;
+
+       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);
-
-       ret = nlm_lck_blocked;
-out_unlock:
-       up(&file->f_sema);
+       nlmsvc_insert_block(newblock, NLM_NEVER);
 out:
+       up(&file->f_sema);
+       nlmsvc_release_block(newblock);
+       nlmsvc_release_block(block);
        dprintk("lockd: nlmsvc_lock returned %u\n", ret);
        return ret;
 }
@@ -446,9 +508,12 @@ 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)
-               status = nlmsvc_delete_block(block, 1);
+       block = nlmsvc_lookup_block(file, lock);
        up(&file->f_sema);
+       if (block != NULL) {
+               status = nlmsvc_unlink_block(block);
+               nlmsvc_release_block(block);
+       }
        return status ? nlm_lck_denied : nlm_granted;
 }
 
@@ -466,7 +531,7 @@ nlmsvc_notify_blocked(struct file_lock *fl)
 
        dprintk("lockd: VFS unblock notification for block %p\n", fl);
        for (bp = &nlm_blocked; (block = *bp) != 0; bp = &block->b_next) {
-               if (nlm_compare_locks(&block->b_call.a_args.lock.fl, fl)) {
+               if (nlm_compare_locks(&block->b_call->a_args.lock.fl, fl)) {
                        nlmsvc_insert_block(block, 0);
                        svc_wake_up(block->b_daemon);
                        return;
@@ -501,16 +566,13 @@ static void
 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 nlm_lock         *lock = &block->b_call->a_args.lock;
        int                     error;
 
        dprintk("lockd: grant blocked lock %p\n", block);
 
-       /* First thing is lock the file */
-       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
@@ -521,37 +583,37 @@ 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);
+       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);
-               goto out_unlock;
+               return;
        default:
                printk(KERN_WARNING "lockd: unexpected error %d in %s!\n",
                                -error, __FUNCTION__);
                nlmsvc_insert_block(block, 10 * HZ);
-               goto out_unlock;
+               return;
        }
 
 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);
-       if (nlmsvc_async_call(&block->b_call, NLMPROC_GRANTED_MSG,
+       kref_get(&block->b_count);
+       if (nlm_async_call(block->b_call, NLMPROC_GRANTED_MSG,
                                                &nlmsvc_grant_ops) < 0)
-               nlm_release_host(block->b_call.a_host);
-out_unlock:
-       up(&file->f_sema);
+               nlmsvc_release_block(block);
 }
 
 /*
@@ -565,20 +627,10 @@ out_unlock:
 static void nlmsvc_grant_callback(struct rpc_task *task, void *data)
 {
        struct nlm_rqst         *call = data;
-       struct nlm_block        *block;
+       struct nlm_block        *block = call->a_block;
        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
@@ -586,22 +638,24 @@ static void nlmsvc_grant_callback(struct rpc_task *task, void *data)
        if (task->tk_status < 0) {
                /* RPC error: Re-insert for retransmission */
                timeout = 10 * HZ;
-       } else if (block->b_done) {
-               /* Block already removed, kill it for real */
-               timeout = 0;
        } else {
                /* Call was successful, now wait for client callback */
                timeout = 60 * HZ;
        }
        nlmsvc_insert_block(block, timeout);
        svc_wake_up(block->b_daemon);
-       block->b_incall = 0;
+}
 
-       nlm_release_host(call->a_host);
+static void nlmsvc_grant_release(void *data)
+{
+       struct nlm_rqst         *call = data;
+
+       nlmsvc_release_block(call->a_block);
 }
 
 static const struct rpc_call_ops nlmsvc_grant_ops = {
        .rpc_call_done = nlmsvc_grant_callback,
+       .rpc_release = nlmsvc_grant_release,
 };
 
 /*
@@ -621,25 +675,17 @@ nlmsvc_grant_reply(struct svc_rqst *rqstp, struct nlm_cookie *cookie, u32 status
                return;
        file = block->b_file;
 
-       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);
                }
        }
-       nlm_release_file(file);
+       nlmsvc_release_block(block);
 }
 
 /*
@@ -660,12 +706,11 @@ nlmsvc_retry_blocked(void)
                        break;
                if (time_after(block->b_when,jiffies))
                        break;
-               dprintk("nlmsvc_retry_blocked(%p, when=%ld, done=%d)\n",
-                       block, block->b_when, block->b_done);
-               if (block->b_done)
-                       nlmsvc_delete_block(block, 0);
-               else
-                       nlmsvc_grant_blocked(block);
+               dprintk("nlmsvc_retry_blocked(%p, when=%ld)\n",
+                       block, block->b_when);
+               kref_get(&block->b_count);
+               nlmsvc_grant_blocked(block);
+               nlmsvc_release_block(block);
        }
 
        if ((block = nlm_blocked) && block->b_when != NLM_NEVER)