Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 245 insertions, 0 deletions

diff --git a/fs/lockd/clntlock.c b/fs/lockd/clntlock.c
new file mode 100644
index 000000000000..ef7103b8c5bd
--- /dev/null
+++ b/fs/lockd/clntlock.c
@@ -0,0 +1,245 @@
+/*
+ * linux/fs/lockd/clntlock.c
+ *
+ * Lock handling for the client side NLM implementation
+ *
+ * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/time.h>
+#include <linux/nfs_fs.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/svc.h>
+#include <linux/lockd/lockd.h>
+#include <linux/smp_lock.h>
+
+#define NLMDBG_FACILITY		NLMDBG_CLIENT
+
+/*
+ * Local function prototypes
+ */
+static int			reclaimer(void *ptr);
+
+/*
+ * The following functions handle blocking and granting from the
+ * client perspective.
+ */
+
+/*
+ * This is the representation of a blocked client lock.
+ */
+struct nlm_wait {
+	struct nlm_wait *	b_next;		/* linked list */
+	wait_queue_head_t	b_wait;		/* where to wait on */
+	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 */
+};
+
+static struct nlm_wait *	nlm_blocked;
+
+/*
+ * Block on a lock
+ */
+int
+nlmclnt_block(struct nlm_host *host, struct file_lock *fl, u32 *statp)
+{
+	struct nlm_wait	block, **head;
+	int		err;
+	u32		pstate;
+
+	block.b_host   = host;
+	block.b_lock   = fl;
+	init_waitqueue_head(&block.b_wait);
+	block.b_status = NLM_LCK_BLOCKED;
+	block.b_next   = nlm_blocked;
+	nlm_blocked    = &block;
+
+	/* Remember pseudo nsm state */
+	pstate = host->h_state;
+
+	/* Go to sleep waiting for GRANT callback. Some servers seem
+	 * to lose callbacks, however, so we're going to poll from
+	 * time to time just to make sure.
+	 *
+	 * For now, the retry frequency is pretty high; normally 
+	 * a 1 minute timeout would do. See the comment before
+	 * nlmclnt_lock for an explanation.
+	 */
+	sleep_on_timeout(&block.b_wait, 30*HZ);
+
+	for (head = &nlm_blocked; *head; head = &(*head)->b_next) {
+		if (*head == &block) {
+			*head = block.b_next;
+			break;
+		}
+	}
+
+	if (!signalled()) {
+		*statp = block.b_status;
+		return 0;
+	}
+
+	/* Okay, we were interrupted. Cancel the pending request
+	 * unless the server has rebooted.
+	 */
+	if (pstate == host->h_state && (err = nlmclnt_cancel(host, fl)) < 0)
+		printk(KERN_NOTICE
+			"lockd: CANCEL call failed (errno %d)\n", -err);
+
+	return -ERESTARTSYS;
+}
+
+/*
+ * The server lockd has called us back to tell us the lock was granted
+ */
+u32
+nlmclnt_grant(struct nlm_lock *lock)
+{
+	struct nlm_wait	*block;
+
+	/*
+	 * Look up blocked request based on arguments. 
+	 * Warning: must not use cookie to match it!
+	 */
+	for (block = nlm_blocked; block; block = block->b_next) {
+		if (nlm_compare_locks(block->b_lock, &lock->fl))
+			break;
+	}
+
+	/* Ooops, no blocked request found. */
+	if (block == NULL)
+		return nlm_lck_denied;
+
+	/* Alright, we found the lock. Set the return status and
+	 * wake up the caller.
+	 */
+	block->b_status = NLM_LCK_GRANTED;
+	wake_up(&block->b_wait);
+
+	return nlm_granted;
+}
+
+/*
+ * The following procedures deal with the recovery of locks after a
+ * server crash.
+ */
+
+/*
+ * Mark the locks for reclaiming.
+ * FIXME: In 2.5 we don't want to iterate through any global file_lock_list.
+ *        Maintain NLM lock reclaiming lists in the nlm_host instead.
+ */
+static
+void nlmclnt_mark_reclaim(struct nlm_host *host)
+{
+	struct file_lock *fl;
+	struct inode *inode;
+	struct list_head *tmp;
+
+	list_for_each(tmp, &file_lock_list) {
+		fl = list_entry(tmp, struct file_lock, fl_link);
+
+		inode = fl->fl_file->f_dentry->d_inode;
+		if (inode->i_sb->s_magic != NFS_SUPER_MAGIC)
+			continue;
+		if (fl->fl_u.nfs_fl.owner->host != host)
+			continue;
+		if (!(fl->fl_u.nfs_fl.flags & NFS_LCK_GRANTED))
+			continue;
+		fl->fl_u.nfs_fl.flags |= NFS_LCK_RECLAIM;
+	}
+}
+
+/*
+ * 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 inline
+void nlmclnt_prepare_reclaim(struct nlm_host *host, u32 newstate)
+{
+	host->h_monitored = 0;
+	host->h_nsmstate = newstate;
+	host->h_state++;
+	host->h_nextrebind = 0;
+	nlm_rebind_host(host);
+	nlmclnt_mark_reclaim(host);
+	dprintk("NLM: 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)
+{
+	if (host->h_reclaiming++) {
+		if (host->h_nsmstate == newstate)
+			return;
+		nlmclnt_prepare_reclaim(host, newstate);
+	} else {
+		nlmclnt_prepare_reclaim(host, newstate);
+		nlm_get_host(host);
+		__module_get(THIS_MODULE);
+		if (kernel_thread(reclaimer, host, CLONE_KERNEL) < 0)
+			module_put(THIS_MODULE);
+	}
+}
+
+static int
+reclaimer(void *ptr)
+{
+	struct nlm_host	  *host = (struct nlm_host *) ptr;
+	struct nlm_wait	  *block;
+	struct list_head *tmp;
+	struct file_lock *fl;
+	struct inode *inode;
+
+	daemonize("%s-reclaim", host->h_name);
+	allow_signal(SIGKILL);
+
+	/* This one ensures that our parent doesn't terminate while the
+	 * reclaim is in progress */
+	lock_kernel();
+	lockd_up();
+
+	/* First, reclaim all locks that have been marked. */
+restart:
+	list_for_each(tmp, &file_lock_list) {
+		fl = list_entry(tmp, struct file_lock, fl_link);
+
+		inode = fl->fl_file->f_dentry->d_inode;
+		if (inode->i_sb->s_magic != NFS_SUPER_MAGIC)
+			continue;
+		if (fl->fl_u.nfs_fl.owner->host != host)
+			continue;
+		if (!(fl->fl_u.nfs_fl.flags & NFS_LCK_RECLAIM))
+			continue;
+
+		fl->fl_u.nfs_fl.flags &= ~NFS_LCK_RECLAIM;
+		nlmclnt_reclaim(host, fl);
+		if (signalled())
+			break;
+		goto restart;
+	}
+
+	host->h_reclaiming = 0;
+
+	/* Now, wake up all processes that sleep on a blocked lock */
+	for (block = nlm_blocked; block; block = block->b_next) {
+		if (block->b_host == host) {
+			block->b_status = NLM_LCK_DENIED_GRACE_PERIOD;
+			wake_up(&block->b_wait);
+		}
+	}
+
+	/* Release host handle after use */
+	nlm_release_host(host);
+	lockd_down();
+	unlock_kernel();
+	module_put_and_exit(0);
+}