linux 2.6.16.38 w/ vs2.0.3-rc1
[linux-2.6.git] / fs / autofs4 / waitq.c
index c0a6c8d..394ff36 100644 (file)
@@ -3,7 +3,7 @@
  * linux/fs/autofs/waitq.c
  *
  *  Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
- *  Copyright 2001-2006 Ian Kent <raven@themaw.net>
+ *  Copyright 2001-2003 Ian Kent <raven@themaw.net>
  *
  * This file is part of the Linux kernel and is made available under
  * the terms of the GNU General Public License, version 2, or at your
@@ -33,7 +33,7 @@ void autofs4_catatonic_mode(struct autofs_sb_info *sbi)
        sbi->catatonic = 1;
        wq = sbi->queues;
        sbi->queues = NULL;     /* Erase all wait queues */
-       while (wq) {
+       while ( wq ) {
                nwq = wq->next;
                wq->status = -ENOENT; /* Magic is gone - report failure */
                kfree(wq->name);
@@ -45,6 +45,8 @@ void autofs4_catatonic_mode(struct autofs_sb_info *sbi)
                fput(sbi->pipe);        /* Close the pipe */
                sbi->pipe = NULL;
        }
+
+       shrink_dcache_sb(sbi->sb);
 }
 
 static int autofs4_write(struct file *file, const void *addr, int bytes)
@@ -96,10 +98,7 @@ static void autofs4_notify_daemon(struct autofs_sb_info *sbi,
 
        pkt.hdr.proto_version = sbi->version;
        pkt.hdr.type = type;
-       switch (type) {
-       /* Kernel protocol v4 missing and expire packets */
-       case autofs_ptype_missing:
-       {
+       if (type == autofs_ptype_missing) {
                struct autofs_packet_missing *mp = &pkt.missing;
 
                pktsz = sizeof(*mp);
@@ -108,10 +107,7 @@ static void autofs4_notify_daemon(struct autofs_sb_info *sbi,
                mp->len = wq->len;
                memcpy(mp->name, wq->name, wq->len);
                mp->name[wq->len] = '\0';
-               break;
-       }
-       case autofs_ptype_expire_multi:
-       {
+       } else if (type == autofs_ptype_expire_multi) {
                struct autofs_packet_expire_multi *ep = &pkt.expire_multi;
 
                pktsz = sizeof(*ep);
@@ -120,34 +116,7 @@ static void autofs4_notify_daemon(struct autofs_sb_info *sbi,
                ep->len = wq->len;
                memcpy(ep->name, wq->name, wq->len);
                ep->name[wq->len] = '\0';
-               break;
-       }
-       /*
-        * Kernel protocol v5 packet for handling indirect and direct
-        * mount missing and expire requests
-        */
-       case autofs_ptype_missing_indirect:
-       case autofs_ptype_expire_indirect:
-       case autofs_ptype_missing_direct:
-       case autofs_ptype_expire_direct:
-       {
-               struct autofs_v5_packet *packet = &pkt.v5_packet;
-
-               pktsz = sizeof(*packet);
-
-               packet->wait_queue_token = wq->wait_queue_token;
-               packet->len = wq->len;
-               memcpy(packet->name, wq->name, wq->len);
-               packet->name[wq->len] = '\0';
-               packet->dev = wq->dev;
-               packet->ino = wq->ino;
-               packet->uid = wq->uid;
-               packet->gid = wq->gid;
-               packet->pid = wq->pid;
-               packet->tgid = wq->tgid;
-               break;
-       }
-       default:
+       } else {
                printk("autofs4_notify_daemon: bad type %d!\n", type);
                return;
        }
@@ -188,96 +157,52 @@ static int autofs4_getpath(struct autofs_sb_info *sbi,
        return len;
 }
 
-static struct autofs_wait_queue *
-autofs4_find_wait(struct autofs_sb_info *sbi,
-                 char *name, unsigned int hash, unsigned int len)
-{
-       struct autofs_wait_queue *wq;
-
-       for (wq = sbi->queues; wq; wq = wq->next) {
-               if (wq->hash == hash &&
-                   wq->len == len &&
-                   wq->name && !memcmp(wq->name, name, len))
-                       break;
-       }
-       return wq;
-}
-
 int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
                enum autofs_notify notify)
 {
-       struct autofs_info *ino;
        struct autofs_wait_queue *wq;
        char *name;
-       unsigned int len = 0;
-       unsigned int hash = 0;
-       int status, type;
+       int len, status;
 
        /* In catatonic mode, we don't wait for nobody */
-       if (sbi->catatonic)
+       if ( sbi->catatonic )
                return -ENOENT;
        
        name = kmalloc(NAME_MAX + 1, GFP_KERNEL);
        if (!name)
                return -ENOMEM;
 
-       /* If this is a direct mount request create a dummy name */
-       if (IS_ROOT(dentry) && (sbi->type & AUTOFS_TYPE_DIRECT))
-               len = sprintf(name, "%p", dentry);
-       else {
-               len = autofs4_getpath(sbi, dentry, &name);
-               if (!len) {
-                       kfree(name);
-                       return -ENOENT;
-               }
+       len = autofs4_getpath(sbi, dentry, &name);
+       if (!len) {
+               kfree(name);
+               return -ENOENT;
        }
-       hash = full_name_hash(name, len);
 
-       if (mutex_lock_interruptible(&sbi->wq_mutex)) {
+       if (down_interruptible(&sbi->wq_sem)) {
                kfree(name);
                return -EINTR;
        }
 
-       wq = autofs4_find_wait(sbi, name, hash, len);
-       ino = autofs4_dentry_ino(dentry);
-       if (!wq && ino && notify == NFY_NONE) {
-               /*
-                * Either we've betean the pending expire to post it's
-                * wait or it finished while we waited on the mutex.
-                * So we need to wait till either, the wait appears
-                * or the expire finishes.
-                */
-
-               while (ino->flags & AUTOFS_INF_EXPIRING) {
-                       mutex_unlock(&sbi->wq_mutex);
-                       schedule_timeout_interruptible(HZ/10);
-                       if (mutex_lock_interruptible(&sbi->wq_mutex)) {
-                               kfree(name);
-                               return -EINTR;
-                       }
-                       wq = autofs4_find_wait(sbi, name, hash, len);
-                       if (wq)
-                               break;
-               }
+       for (wq = sbi->queues ; wq ; wq = wq->next) {
+               if (wq->hash == dentry->d_name.hash &&
+                   wq->len == len &&
+                   wq->name && !memcmp(wq->name, name, len))
+                       break;
+       }
 
-               /*
-                * Not ideal but the status has already gone. Of the two
-                * cases where we wait on NFY_NONE neither depend on the
-                * return status of the wait.
-                */
-               if (!wq) {
+       if ( !wq ) {
+               /* Can't wait for an expire if there's no mount */
+               if (notify == NFY_NONE && !d_mountpoint(dentry)) {
                        kfree(name);
-                       mutex_unlock(&sbi->wq_mutex);
-                       return 0;
+                       up(&sbi->wq_sem);
+                       return -ENOENT;
                }
-       }
 
-       if (!wq) {
                /* Create a new wait queue */
                wq = kmalloc(sizeof(struct autofs_wait_queue),GFP_KERNEL);
-               if (!wq) {
+               if ( !wq ) {
                        kfree(name);
-                       mutex_unlock(&sbi->wq_mutex);
+                       up(&sbi->wq_sem);
                        return -ENOMEM;
                }
 
@@ -287,58 +212,42 @@ int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
                wq->next = sbi->queues;
                sbi->queues = wq;
                init_waitqueue_head(&wq->queue);
-               wq->hash = hash;
+               wq->hash = dentry->d_name.hash;
                wq->name = name;
                wq->len = len;
-               wq->dev = autofs4_get_dev(sbi);
-               wq->ino = autofs4_get_ino(sbi);
-               wq->uid = current->uid;
-               wq->gid = current->gid;
-               wq->pid = current->pid;
-               wq->tgid = current->tgid;
                wq->status = -EINTR; /* Status return if interrupted */
                atomic_set(&wq->wait_ctr, 2);
-               mutex_unlock(&sbi->wq_mutex);
-
-               if (sbi->version < 5) {
-                       if (notify == NFY_MOUNT)
-                               type = autofs_ptype_missing;
-                       else
-                               type = autofs_ptype_expire_multi;
-               } else {
-                       if (notify == NFY_MOUNT)
-                               type = (sbi->type & AUTOFS_TYPE_DIRECT) ?
-                                       autofs_ptype_missing_direct :
-                                        autofs_ptype_missing_indirect;
-                       else
-                               type = (sbi->type & AUTOFS_TYPE_DIRECT) ?
-                                       autofs_ptype_expire_direct :
-                                       autofs_ptype_expire_indirect;
-               }
+               atomic_set(&wq->notified, 1);
+               up(&sbi->wq_sem);
+       } else {
+               atomic_inc(&wq->wait_ctr);
+               up(&sbi->wq_sem);
+               kfree(name);
+               DPRINTK("existing wait id = 0x%08lx, name = %.*s, nfy=%d",
+                       (unsigned long) wq->wait_queue_token, wq->len, wq->name, notify);
+       }
+
+       if (notify != NFY_NONE && atomic_dec_and_test(&wq->notified)) {
+               int type = (notify == NFY_MOUNT ?
+                       autofs_ptype_missing : autofs_ptype_expire_multi);
 
                DPRINTK("new wait id = 0x%08lx, name = %.*s, nfy=%d\n",
                        (unsigned long) wq->wait_queue_token, wq->len, wq->name, notify);
 
                /* autofs4_notify_daemon() may block */
                autofs4_notify_daemon(sbi, wq, type);
-       } else {
-               atomic_inc(&wq->wait_ctr);
-               mutex_unlock(&sbi->wq_mutex);
-               kfree(name);
-               DPRINTK("existing wait id = 0x%08lx, name = %.*s, nfy=%d",
-                       (unsigned long) wq->wait_queue_token, wq->len, wq->name, notify);
        }
 
        /* wq->name is NULL if and only if the lock is already released */
 
-       if (sbi->catatonic) {
+       if ( sbi->catatonic ) {
                /* We might have slept, so check again for catatonic mode */
                wq->status = -ENOENT;
                kfree(wq->name);
                wq->name = NULL;
        }
 
-       if (wq->name) {
+       if ( wq->name ) {
                /* Block all but "shutdown" signals while waiting */
                sigset_t oldset;
                unsigned long irqflags;
@@ -373,19 +282,19 @@ int autofs4_wait_release(struct autofs_sb_info *sbi, autofs_wqt_t wait_queue_tok
 {
        struct autofs_wait_queue *wq, **wql;
 
-       mutex_lock(&sbi->wq_mutex);
-       for (wql = &sbi->queues ; (wq = *wql) != 0 ; wql = &wq->next) {
-               if (wq->wait_queue_token == wait_queue_token)
+       down(&sbi->wq_sem);
+       for ( wql = &sbi->queues ; (wq = *wql) != 0 ; wql = &wq->next ) {
+               if ( wq->wait_queue_token == wait_queue_token )
                        break;
        }
 
-       if (!wq) {
-               mutex_unlock(&sbi->wq_mutex);
+       if ( !wq ) {
+               up(&sbi->wq_sem);
                return -EINVAL;
        }
 
        *wql = wq->next;        /* Unlink from chain */
-       mutex_unlock(&sbi->wq_mutex);
+       up(&sbi->wq_sem);
        kfree(wq->name);
        wq->name = NULL;        /* Do not wait on this queue */