* linux/fs/autofs/waitq.c
*
* Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
+ * Copyright 2001-2006 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
{
struct autofs_wait_queue *wq, *nwq;
- DPRINTK(("autofs: entering catatonic mode\n"));
+ DPRINTK("entering catatonic mode");
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);
wq->name = NULL;
- wake_up(&wq->queue);
+ wake_up_interruptible(&wq->queue);
wq = nwq;
}
- if (sbi->pipe) {
- fput(sbi->pipe); /* Close the pipe */
- sbi->pipe = NULL;
- }
-
- shrink_dcache_sb(sbi->sb);
+ fput(sbi->pipe); /* Close the pipe */
+ sbi->pipe = NULL;
}
static int autofs4_write(struct file *file, const void *addr, int bytes)
union autofs_packet_union pkt;
size_t pktsz;
- DPRINTK(("autofs_notify: wait id = 0x%08lx, name = %.*s, type=%d\n",
- wq->wait_queue_token, wq->len, wq->name, type));
+ DPRINTK("wait id = 0x%08lx, name = %.*s, type=%d",
+ wq->wait_queue_token, wq->len, wq->name, type);
memset(&pkt,0,sizeof pkt); /* For security reasons */
pkt.hdr.proto_version = sbi->version;
pkt.hdr.type = type;
- if (type == autofs_ptype_missing) {
+ switch (type) {
+ /* Kernel protocol v4 missing and expire packets */
+ case autofs_ptype_missing:
+ {
struct autofs_packet_missing *mp = &pkt.missing;
pktsz = sizeof(*mp);
mp->len = wq->len;
memcpy(mp->name, wq->name, wq->len);
mp->name[wq->len] = '\0';
- } else if (type == autofs_ptype_expire_multi) {
+ break;
+ }
+ case autofs_ptype_expire_multi:
+ {
struct autofs_packet_expire_multi *ep = &pkt.expire_multi;
pktsz = sizeof(*ep);
ep->len = wq->len;
memcpy(ep->name, wq->name, wq->len);
ep->name[wq->len] = '\0';
- } else {
- printk("autofs_notify_daemon: bad type %d!\n", type);
+ 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:
+ printk("autofs4_notify_daemon: bad type %d!\n", type);
return;
}
autofs4_catatonic_mode(sbi);
}
-int autofs4_wait(struct autofs_sb_info *sbi, struct qstr *name,
+static int autofs4_getpath(struct autofs_sb_info *sbi,
+ struct dentry *dentry, char **name)
+{
+ struct dentry *root = sbi->sb->s_root;
+ struct dentry *tmp;
+ char *buf = *name;
+ char *p;
+ int len = 0;
+
+ spin_lock(&dcache_lock);
+ for (tmp = dentry ; tmp != root ; tmp = tmp->d_parent)
+ len += tmp->d_name.len + 1;
+
+ if (--len > NAME_MAX) {
+ spin_unlock(&dcache_lock);
+ return 0;
+ }
+
+ *(buf + len) = '\0';
+ p = buf + len - dentry->d_name.len;
+ strncpy(p, dentry->d_name.name, dentry->d_name.len);
+
+ for (tmp = dentry->d_parent; tmp != root ; tmp = tmp->d_parent) {
+ *(--p) = '/';
+ p -= tmp->d_name.len;
+ strncpy(p, tmp->d_name.name, tmp->d_name.len);
+ }
+ spin_unlock(&dcache_lock);
+
+ 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;
- int status;
+ char *name;
+ unsigned int len = 0;
+ unsigned int hash = 0;
+ int status, type;
/* In catatonic mode, we don't wait for nobody */
- if ( sbi->catatonic )
+ if (sbi->catatonic)
return -ENOENT;
- /* We shouldn't be able to get here, but just in case */
- if ( name->len > NAME_MAX )
- 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;
+ }
+ }
+ hash = full_name_hash(name, len);
- for ( wq = sbi->queues ; wq ; wq = wq->next ) {
- if ( wq->hash == name->hash &&
- wq->len == name->len &&
- wq->name && !memcmp(wq->name,name->name,name->len) )
- break;
+ if (mutex_lock_interruptible(&sbi->wq_mutex)) {
+ kfree(name);
+ return -EINTR;
}
-
- if ( !wq ) {
+
+ 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;
+ }
+
+ /*
+ * 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) {
+ kfree(name);
+ mutex_unlock(&sbi->wq_mutex);
+ return 0;
+ }
+ }
+
+ if (!wq) {
/* Create a new wait queue */
wq = kmalloc(sizeof(struct autofs_wait_queue),GFP_KERNEL);
- if ( !wq )
- return -ENOMEM;
-
- wq->name = kmalloc(name->len,GFP_KERNEL);
- if ( !wq->name ) {
- kfree(wq);
+ if (!wq) {
+ kfree(name);
+ mutex_unlock(&sbi->wq_mutex);
return -ENOMEM;
}
+
wq->wait_queue_token = autofs4_next_wait_queue;
if (++autofs4_next_wait_queue == 0)
autofs4_next_wait_queue = 1;
- init_waitqueue_head(&wq->queue);
- wq->hash = name->hash;
- wq->len = name->len;
- wq->status = -EINTR; /* Status return if interrupted */
- memcpy(wq->name, name->name, name->len);
wq->next = sbi->queues;
sbi->queues = wq;
+ init_waitqueue_head(&wq->queue);
+ wq->hash = 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;
+ }
+
+ DPRINTK("new wait id = 0x%08lx, name = %.*s, nfy=%d\n",
+ (unsigned long) wq->wait_queue_token, wq->len, wq->name, notify);
- DPRINTK(("autofs_wait: new wait id = 0x%08lx, name = %.*s, nfy=%d\n",
- wq->wait_queue_token, wq->len, wq->name, notify));
/* autofs4_notify_daemon() may block */
- wq->wait_ctr = 2;
- if (notify != NFY_NONE) {
- autofs4_notify_daemon(sbi,wq,
- notify == NFY_MOUNT ? autofs_ptype_missing :
- autofs_ptype_expire_multi);
- }
+ autofs4_notify_daemon(sbi, wq, type);
} else {
- wq->wait_ctr++;
- DPRINTK(("autofs_wait: existing wait id = 0x%08lx, name = %.*s, nfy=%d\n",
- wq->wait_queue_token, wq->len, wq->name, notify));
+ 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;
- if ( wq->name ) {
- kfree(wq->name);
- wq->name = NULL;
- }
+ 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;
recalc_sigpending();
spin_unlock_irqrestore(¤t->sighand->siglock, irqflags);
- interruptible_sleep_on(&wq->queue);
+ wait_event_interruptible(wq->queue, wq->name == NULL);
spin_lock_irqsave(¤t->sighand->siglock, irqflags);
current->blocked = oldset;
recalc_sigpending();
spin_unlock_irqrestore(¤t->sighand->siglock, irqflags);
} else {
- DPRINTK(("autofs_wait: skipped sleeping\n"));
+ DPRINTK("skipped sleeping");
}
status = wq->status;
- if (--wq->wait_ctr == 0) /* Are we the last process to need status? */
+ /* Are we the last process to need status? */
+ if (atomic_dec_and_test(&wq->wait_ctr))
kfree(wq);
return status;
{
struct autofs_wait_queue *wq, **wql;
- for ( wql = &sbi->queues ; (wq = *wql) ; wql = &wq->next ) {
- if ( wq->wait_queue_token == wait_queue_token )
+ mutex_lock(&sbi->wq_mutex);
+ for (wql = &sbi->queues ; (wq = *wql) != 0 ; wql = &wq->next) {
+ if (wq->wait_queue_token == wait_queue_token)
break;
}
- if ( !wq )
+
+ if (!wq) {
+ mutex_unlock(&sbi->wq_mutex);
return -EINVAL;
+ }
*wql = wq->next; /* Unlink from chain */
+ mutex_unlock(&sbi->wq_mutex);
kfree(wq->name);
wq->name = NULL; /* Do not wait on this queue */
wq->status = status;
- if (--wq->wait_ctr == 0) /* Is anyone still waiting for this guy? */
+ if (atomic_dec_and_test(&wq->wait_ctr)) /* Is anyone still waiting for this guy? */
kfree(wq);
else
- wake_up(&wq->queue);
+ wake_up_interruptible(&wq->queue);
return 0;
}
git://git.onelab.eu / linux-2.6.git / blobdiff