* linux/fs/autofs/waitq.c
*
* Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
- * Copyright 2001-2003 Ian Kent <raven@themaw.net>
+ * 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;
+ mutex_lock(&sbi->wq_mutex);
+ if (sbi->catatonic) {
+ mutex_unlock(&sbi->wq_mutex);
+ return;
+ }
+
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;
+ if (wq->name.name) {
+ kfree(wq->name.name);
+ wq->name.name = NULL;
+ }
+ wq->wait_ctr--;
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;
+ sbi->pipefd = -1;
+ mutex_unlock(&sbi->wq_mutex);
}
static int autofs4_write(struct file *file, const void *addr, int bytes)
struct autofs_wait_queue *wq,
int type)
{
- union autofs_packet_union pkt;
+ union {
+ struct autofs_packet_hdr hdr;
+ union autofs_packet_union v4_pkt;
+ union autofs_v5_packet_union v5_pkt;
+ } pkt;
+ struct file *pipe = NULL;
size_t pktsz;
DPRINTK("wait id = 0x%08lx, name = %.*s, type=%d",
- wq->wait_queue_token, wq->len, wq->name, type);
+ wq->wait_queue_token, wq->name.len, wq->name.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) {
- struct autofs_packet_missing *mp = &pkt.missing;
+ switch (type) {
+ /* Kernel protocol v4 missing and expire packets */
+ case autofs_ptype_missing:
+ {
+ struct autofs_packet_missing *mp = &pkt.v4_pkt.missing;
pktsz = sizeof(*mp);
mp->wait_queue_token = wq->wait_queue_token;
- mp->len = wq->len;
- memcpy(mp->name, wq->name, wq->len);
- mp->name[wq->len] = '\0';
- } else if (type == autofs_ptype_expire_multi) {
- struct autofs_packet_expire_multi *ep = &pkt.expire_multi;
+ mp->len = wq->name.len;
+ memcpy(mp->name, wq->name.name, wq->name.len);
+ mp->name[wq->name.len] = '\0';
+ break;
+ }
+ case autofs_ptype_expire_multi:
+ {
+ struct autofs_packet_expire_multi *ep = &pkt.v4_pkt.expire_multi;
pktsz = sizeof(*ep);
ep->wait_queue_token = wq->wait_queue_token;
- ep->len = wq->len;
- memcpy(ep->name, wq->name, wq->len);
- ep->name[wq->len] = '\0';
- } else {
+ ep->len = wq->name.len;
+ memcpy(ep->name, wq->name.name, wq->name.len);
+ ep->name[wq->name.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_pkt.v5_packet;
+
+ pktsz = sizeof(*packet);
+
+ packet->wait_queue_token = wq->wait_queue_token;
+ packet->len = wq->name.len;
+ memcpy(packet->name, wq->name.name, wq->name.len);
+ packet->name[wq->name.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;
}
- if (autofs4_write(sbi->pipe, &pkt, pktsz))
- autofs4_catatonic_mode(sbi);
+ /* Check if we have become catatonic */
+ mutex_lock(&sbi->wq_mutex);
+ if (!sbi->catatonic) {
+ pipe = sbi->pipe;
+ get_file(pipe);
+ }
+ mutex_unlock(&sbi->wq_mutex);
+
+ if (pipe) {
+ if (autofs4_write(pipe, &pkt, pktsz))
+ autofs4_catatonic_mode(sbi);
+ fput(pipe);
+ }
}
static int autofs4_getpath(struct autofs_sb_info *sbi,
for (tmp = dentry ; tmp != root ; tmp = tmp->d_parent)
len += tmp->d_name.len + 1;
- if (--len > NAME_MAX) {
+ if (!len || --len > NAME_MAX) {
spin_unlock(&dcache_lock);
return 0;
}
return len;
}
+static struct autofs_wait_queue *
+autofs4_find_wait(struct autofs_sb_info *sbi, struct qstr *qstr)
+{
+ struct autofs_wait_queue *wq;
+
+ for (wq = sbi->queues; wq; wq = wq->next) {
+ if (wq->name.hash == qstr->hash &&
+ wq->name.len == qstr->len &&
+ wq->name.name &&
+ !memcmp(wq->name.name, qstr->name, qstr->len))
+ break;
+ }
+ return wq;
+}
+
+/*
+ * Check if we have a valid request.
+ * Returns
+ * 1 if the request should continue.
+ * In this case we can return an autofs_wait_queue entry if one is
+ * found or NULL to idicate a new wait needs to be created.
+ * 0 or a negative errno if the request shouldn't continue.
+ */
+static int validate_request(struct autofs_wait_queue **wait,
+ struct autofs_sb_info *sbi,
+ struct qstr *qstr,
+ struct dentry*dentry, enum autofs_notify notify)
+{
+ struct autofs_wait_queue *wq;
+ struct autofs_info *ino;
+
+ /* Wait in progress, continue; */
+ wq = autofs4_find_wait(sbi, qstr);
+ if (wq) {
+ *wait = wq;
+ return 1;
+ }
+
+ *wait = NULL;
+
+ /* If we don't yet have any info this is a new request */
+ ino = autofs4_dentry_ino(dentry);
+ if (!ino)
+ return 1;
+
+ /*
+ * If we've been asked to wait on an existing expire (NFY_NONE)
+ * but there is no wait in the queue ...
+ */
+ if (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))
+ return -EINTR;
+
+ wq = autofs4_find_wait(sbi, qstr);
+ if (wq) {
+ *wait = wq;
+ return 1;
+ }
+ }
+
+ /*
+ * 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.
+ */
+ return 0;
+ }
+
+ /*
+ * If we've been asked to trigger a mount and the request
+ * completed while we waited on the mutex ...
+ */
+ if (notify == NFY_MOUNT) {
+ /*
+ * If the dentry was successfully mounted while we slept
+ * on the wait queue mutex we can return success. If it
+ * isn't mounted (doesn't have submounts for the case of
+ * a multi-mount with no mount at it's base) we can
+ * continue on and create a new request.
+ */
+ if (have_submounts(dentry))
+ return 0;
+ }
+
+ return 1;
+}
+
int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
enum autofs_notify notify)
{
struct autofs_wait_queue *wq;
+ struct qstr qstr;
char *name;
- int len, status;
+ int status, ret, type;
/* In catatonic mode, we don't wait for nobody */
- if ( sbi->catatonic )
+ if (sbi->catatonic)
return -ENOENT;
-
+
+ if (!dentry->d_inode) {
+ /*
+ * A wait for a negative dentry is invalid for certain
+ * cases. A direct or offset mount "always" has its mount
+ * point directory created and so the request dentry must
+ * be positive or the map key doesn't exist. The situation
+ * is very similar for indirect mounts except only dentrys
+ * in the root of the autofs file system may be negative.
+ */
+ if (autofs_type_trigger(sbi->type))
+ return -ENOENT;
+ else if (!IS_ROOT(dentry->d_parent))
+ return -ENOENT;
+ }
+
name = kmalloc(NAME_MAX + 1, GFP_KERNEL);
if (!name)
return -ENOMEM;
- len = autofs4_getpath(sbi, dentry, &name);
- if (!len) {
- kfree(name);
- return -ENOENT;
+ /* If this is a direct mount request create a dummy name */
+ if (IS_ROOT(dentry) && autofs_type_trigger(sbi->type))
+ qstr.len = sprintf(name, "%p", dentry);
+ else {
+ qstr.len = autofs4_getpath(sbi, dentry, &name);
+ if (!qstr.len) {
+ kfree(name);
+ return -ENOENT;
+ }
}
+ qstr.name = name;
+ qstr.hash = full_name_hash(name, qstr.len);
- if (down_interruptible(&sbi->wq_sem)) {
- kfree(name);
+ if (mutex_lock_interruptible(&sbi->wq_mutex)) {
+ kfree(qstr.name);
return -EINTR;
}
- 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;
+ ret = validate_request(&wq, sbi, &qstr, dentry, notify);
+ if (ret <= 0) {
+ if (ret == 0)
+ mutex_unlock(&sbi->wq_mutex);
+ kfree(qstr.name);
+ return ret;
}
- if ( !wq ) {
+ if (!wq) {
/* Create a new wait queue */
wq = kmalloc(sizeof(struct autofs_wait_queue),GFP_KERNEL);
- if ( !wq ) {
- kfree(name);
- up(&sbi->wq_sem);
+ if (!wq) {
+ kfree(qstr.name);
+ mutex_unlock(&sbi->wq_mutex);
return -ENOMEM;
}
wq->next = sbi->queues;
sbi->queues = wq;
init_waitqueue_head(&wq->queue);
- wq->hash = dentry->d_name.hash;
- wq->name = name;
- wq->len = len;
+ memcpy(&wq->name, &qstr, sizeof(struct qstr));
+ 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);
- 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);
+ 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 = autofs_type_trigger(sbi->type) ?
+ autofs_ptype_missing_direct :
+ autofs_ptype_missing_indirect;
+ else
+ type = autofs_type_trigger(sbi->type) ?
+ 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("new wait id = 0x%08lx, name = %.*s, nfy=%d\n",
+ (unsigned long) wq->wait_queue_token, wq->name.len,
+ wq->name.name, notify);
/* autofs4_notify_daemon() may block */
autofs4_notify_daemon(sbi, wq, type);
+ } else {
+ wq->wait_ctr++;
+ mutex_unlock(&sbi->wq_mutex);
+ kfree(qstr.name);
+ DPRINTK("existing wait id = 0x%08lx, name = %.*s, nfy=%d",
+ (unsigned long) wq->wait_queue_token, wq->name.len,
+ wq->name.name, notify);
}
- /* wq->name is NULL if and only if the lock is already released */
-
- 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;
- }
- }
-
- if ( wq->name ) {
+ /*
+ * wq->name.name is NULL iff the lock is already released
+ * or the mount has been made catatonic.
+ */
+ if (wq->name.name) {
/* Block all but "shutdown" signals while waiting */
sigset_t oldset;
unsigned long irqflags;
recalc_sigpending();
spin_unlock_irqrestore(¤t->sighand->siglock, irqflags);
- wait_event_interruptible(wq->queue, wq->name == NULL);
+ wait_event_interruptible(wq->queue, wq->name.name == NULL);
spin_lock_irqsave(¤t->sighand->siglock, irqflags);
current->blocked = oldset;
status = wq->status;
+ /*
+ * For direct and offset mounts we need to track the requester's
+ * uid and gid in the dentry info struct. This is so it can be
+ * supplied, on request, by the misc device ioctl interface.
+ * This is needed during daemon resatart when reconnecting
+ * to existing, active, autofs mounts. The uid and gid (and
+ * related string values) may be used for macro substitution
+ * in autofs mount maps.
+ */
+ if (!status) {
+ struct autofs_info *ino;
+ struct dentry *de = NULL;
+
+ /* direct mount or browsable map */
+ ino = autofs4_dentry_ino(dentry);
+ if (!ino) {
+ /* If not lookup actual dentry used */
+ de = d_lookup(dentry->d_parent, &dentry->d_name);
+ if (de)
+ ino = autofs4_dentry_ino(de);
+ }
+
+ /* Set mount requester */
+ if (ino) {
+ spin_lock(&sbi->fs_lock);
+ ino->uid = wq->uid;
+ ino->gid = wq->gid;
+ spin_unlock(&sbi->fs_lock);
+ }
+
+ if (de)
+ dput(de);
+ }
+
/* Are we the last process to need status? */
- if (atomic_dec_and_test(&wq->wait_ctr))
+ mutex_lock(&sbi->wq_mutex);
+ if (!--wq->wait_ctr)
kfree(wq);
+ mutex_unlock(&sbi->wq_mutex);
return status;
}
{
struct autofs_wait_queue *wq, **wql;
- down(&sbi->wq_sem);
- for ( wql = &sbi->queues ; (wq = *wql) != 0 ; wql = &wq->next ) {
- if ( wq->wait_queue_token == wait_queue_token )
+ mutex_lock(&sbi->wq_mutex);
+ for (wql = &sbi->queues; (wq = *wql) != NULL; wql = &wq->next) {
+ if (wq->wait_queue_token == wait_queue_token)
break;
}
- if ( !wq ) {
- up(&sbi->wq_sem);
+ if (!wq) {
+ mutex_unlock(&sbi->wq_mutex);
return -EINVAL;
}
*wql = wq->next; /* Unlink from chain */
- up(&sbi->wq_sem);
- kfree(wq->name);
- wq->name = NULL; /* Do not wait on this queue */
-
+ kfree(wq->name.name);
+ wq->name.name = NULL; /* Do not wait on this queue */
wq->status = status;
-
- if (atomic_dec_and_test(&wq->wait_ctr)) /* Is anyone still waiting for this guy? */
+ wake_up_interruptible(&wq->queue);
+ if (!--wq->wait_ctr)
kfree(wq);
- else
- wake_up_interruptible(&wq->queue);
+ mutex_unlock(&sbi->wq_mutex);
return 0;
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff