lockd: convert reclaimer thread to kthread interface
[linux-2.6.git] / fs / lockd / clntlock.c
index 87e1d03..94d42cc 100644 (file)
@@ -14,6 +14,7 @@
 #include <linux/sunrpc/svc.h>
 #include <linux/lockd/lockd.h>
 #include <linux/smp_lock.h>
+#include <linux/kthread.h>
 
 #define NLMDBG_FACILITY                NLMDBG_CLIENT
 
@@ -36,11 +37,52 @@ struct nlm_wait {
        struct nlm_host *       b_host;
        struct file_lock *      b_lock;         /* local file lock */
        unsigned short          b_reclaim;      /* got to reclaim lock */
-       u32                     b_status;       /* grant callback status */
+       __be32                  b_status;       /* grant callback status */
 };
 
 static LIST_HEAD(nlm_blocked);
 
+/**
+ * nlmclnt_init - Set up per-NFS mount point lockd data structures
+ * @nlm_init: pointer to arguments structure
+ *
+ * Returns pointer to an appropriate nlm_host struct,
+ * or an ERR_PTR value.
+ */
+struct nlm_host *nlmclnt_init(const struct nlmclnt_initdata *nlm_init)
+{
+       struct nlm_host *host;
+       u32 nlm_version = (nlm_init->nfs_version == 2) ? 1 : 4;
+       int status;
+
+       status = lockd_up();
+       if (status < 0)
+               return ERR_PTR(status);
+
+       host = nlmclnt_lookup_host(nlm_init->address, nlm_init->addrlen,
+                                  nlm_init->protocol, nlm_version,
+                                  nlm_init->hostname);
+       if (host == NULL) {
+               lockd_down();
+               return ERR_PTR(-ENOLCK);
+       }
+
+       return host;
+}
+EXPORT_SYMBOL_GPL(nlmclnt_init);
+
+/**
+ * nlmclnt_done - Release resources allocated by nlmclnt_init()
+ * @host: nlm_host structure reserved by nlmclnt_init()
+ *
+ */
+void nlmclnt_done(struct nlm_host *host)
+{
+       nlm_release_host(host);
+       lockd_down();
+}
+EXPORT_SYMBOL_GPL(nlmclnt_done);
+
 /*
  * Queue up a lock for blocking so that the GRANTED request can see it
  */
@@ -53,7 +95,7 @@ struct nlm_wait *nlmclnt_prepare_block(struct nlm_host *host, struct file_lock *
                block->b_host = host;
                block->b_lock = fl;
                init_waitqueue_head(&block->b_wait);
-               block->b_status = NLM_LCK_BLOCKED;
+               block->b_status = nlm_lck_blocked;
                list_add(&block->b_list, &nlm_blocked);
        }
        return block;
@@ -89,7 +131,7 @@ int nlmclnt_block(struct nlm_wait *block, struct nlm_rqst *req, long timeout)
         * nlmclnt_lock for an explanation.
         */
        ret = wait_event_interruptible_timeout(block->b_wait,
-                       block->b_status != NLM_LCK_BLOCKED,
+                       block->b_status != nlm_lck_blocked,
                        timeout);
        if (ret < 0)
                return -ERESTARTSYS;
@@ -100,12 +142,12 @@ int nlmclnt_block(struct nlm_wait *block, struct nlm_rqst *req, long timeout)
 /*
  * The server lockd has called us back to tell us the lock was granted
  */
-u32 nlmclnt_grant(const struct sockaddr_in *addr, const struct nlm_lock *lock)
+__be32 nlmclnt_grant(const struct sockaddr *addr, const struct nlm_lock *lock)
 {
        const struct file_lock *fl = &lock->fl;
        const struct nfs_fh *fh = &lock->fh;
        struct nlm_wait *block;
-       u32 res = nlm_lck_denied;
+       __be32 res = nlm_lck_denied;
 
        /*
         * Look up blocked request based on arguments. 
@@ -124,14 +166,14 @@ u32 nlmclnt_grant(const struct sockaddr_in *addr, const struct nlm_lock *lock)
                 */
                if (fl_blocked->fl_u.nfs_fl.owner->pid != lock->svid)
                        continue;
-               if (!nlm_cmp_addr(&block->b_host->h_addr, addr))
+               if (!nlm_cmp_addr(nlm_addr(block->b_host), addr))
                        continue;
-               if (nfs_compare_fh(NFS_FH(fl_blocked->fl_file->f_dentry->d_inode) ,fh) != 0)
+               if (nfs_compare_fh(NFS_FH(fl_blocked->fl_file->f_path.dentry->d_inode) ,fh) != 0)
                        continue;
                /* Alright, we found a lock. Set the return status
                 * and wake up the caller
                 */
-               block->b_status = NLM_LCK_GRANTED;
+               block->b_status = nlm_granted;
                wake_up(&block->b_wait);
                res = nlm_granted;
        }
@@ -144,47 +186,21 @@ u32 nlmclnt_grant(const struct sockaddr_in *addr, const struct nlm_lock *lock)
  */
 
 /*
- * Someone has sent us an SM_NOTIFY. Ensure we bind to the new port number,
- * that we mark locks for reclaiming, and that we bump the pseudo NSM state.
- */
-static void nlmclnt_prepare_reclaim(struct nlm_host *host)
-{
-       down_write(&host->h_rwsem);
-       host->h_monitored = 0;
-       host->h_state++;
-       host->h_nextrebind = 0;
-       nlm_rebind_host(host);
-
-       /*
-        * Mark the locks for reclaiming.
-        */
-       list_splice_init(&host->h_granted, &host->h_reclaim);
-
-       dprintk("NLM: reclaiming locks for host %s\n", host->h_name);
-}
-
-static void nlmclnt_finish_reclaim(struct nlm_host *host)
-{
-       host->h_reclaiming = 0;
-       up_write(&host->h_rwsem);
-       dprintk("NLM: done reclaiming locks for host %s", host->h_name);
-}
-
-/*
  * Reclaim all locks on server host. We do this by spawning a separate
  * reclaimer thread.
  */
 void
-nlmclnt_recovery(struct nlm_host *host, u32 newstate)
+nlmclnt_recovery(struct nlm_host *host)
 {
-       if (host->h_nsmstate == newstate)
-               return;
-       host->h_nsmstate = newstate;
+       struct task_struct *task;
+
        if (!host->h_reclaiming++) {
                nlm_get_host(host);
-               __module_get(THIS_MODULE);
-               if (kernel_thread(reclaimer, host, CLONE_KERNEL) < 0)
-                       module_put(THIS_MODULE);
+               task = kthread_run(reclaimer, host, "%s-reclaim", host->h_name);
+               if (IS_ERR(task))
+                       printk(KERN_ERR "lockd: unable to spawn reclaimer "
+                               "thread. Locks for %s won't be reclaimed! "
+                               "(%ld)\n", host->h_name, PTR_ERR(task));
        }
 }
 
@@ -196,21 +212,37 @@ reclaimer(void *ptr)
        struct file_lock *fl, *next;
        u32 nsmstate;
 
-       daemonize("%s-reclaim", host->h_name);
        allow_signal(SIGKILL);
 
+       down_write(&host->h_rwsem);
+
        /* This one ensures that our parent doesn't terminate while the
         * reclaim is in progress */
        lock_kernel();
-       lockd_up(0); /* note: this cannot fail as lockd is already running */
+       lockd_up();     /* note: this cannot fail as lockd is already running */
+
+       dprintk("lockd: reclaiming locks for host %s\n", host->h_name);
 
-       nlmclnt_prepare_reclaim(host);
-       /* First, reclaim all locks that have been marked. */
 restart:
        nsmstate = host->h_nsmstate;
+
+       /* Force a portmap getport - the peer's lockd will
+        * most likely end up on a different port.
+        */
+       host->h_nextrebind = jiffies;
+       nlm_rebind_host(host);
+
+       /* First, reclaim all locks that have been granted. */
+       list_splice_init(&host->h_granted, &host->h_reclaim);
        list_for_each_entry_safe(fl, next, &host->h_reclaim, fl_u.nfs_fl.list) {
                list_del_init(&fl->fl_u.nfs_fl.list);
 
+               /*
+                * sending this thread a SIGKILL will result in any unreclaimed
+                * locks being removed from the h_granted list. This means that
+                * the kernel will not attempt to reclaim them again if a new
+                * reclaimer thread is spawned for this host.
+                */
                if (signalled())
                        continue;
                if (nlmclnt_reclaim(host, fl) != 0)
@@ -218,16 +250,18 @@ restart:
                list_add_tail(&fl->fl_u.nfs_fl.list, &host->h_granted);
                if (host->h_nsmstate != nsmstate) {
                        /* Argh! The server rebooted again! */
-                       list_splice_init(&host->h_granted, &host->h_reclaim);
                        goto restart;
                }
        }
-       nlmclnt_finish_reclaim(host);
+
+       host->h_reclaiming = 0;
+       up_write(&host->h_rwsem);
+       dprintk("NLM: done reclaiming locks for host %s\n", host->h_name);
 
        /* Now, wake up all processes that sleep on a blocked lock */
        list_for_each_entry(block, &nlm_blocked, b_list) {
                if (block->b_host == host) {
-                       block->b_status = NLM_LCK_DENIED_GRACE_PERIOD;
+                       block->b_status = nlm_lck_denied_grace_period;
                        wake_up(&block->b_wait);
                }
        }
@@ -236,5 +270,5 @@ restart:
        nlm_release_host(host);
        lockd_down();
        unlock_kernel();
-       module_put_and_exit(0);
+       return 0;
 }