ALSA: usb-audio: add support for Akai MPD16
[safe/jmp/linux-2.6] / fs / autofs4 / waitq.c
index c0a6c8d..2341375 100644 (file)
@@ -28,6 +28,12 @@ void autofs4_catatonic_mode(struct autofs_sb_info *sbi)
 {
        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;
@@ -36,15 +42,18 @@ void autofs4_catatonic_mode(struct autofs_sb_info *sbi)
        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;
-       }
+       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)
@@ -86,11 +95,16 @@ static void autofs4_notify_daemon(struct autofs_sb_info *sbi,
                                 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 */
 
@@ -100,26 +114,26 @@ static void autofs4_notify_daemon(struct autofs_sb_info *sbi,
        /* Kernel protocol v4 missing and expire packets */
        case autofs_ptype_missing:
        {
-               struct autofs_packet_missing *mp = &pkt.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';
+               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.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';
+               ep->len = wq->name.len;
+               memcpy(ep->name, wq->name.name, wq->name.len);
+               ep->name[wq->name.len] = '\0';
                break;
        }
        /*
@@ -131,14 +145,14 @@ static void autofs4_notify_daemon(struct autofs_sb_info *sbi,
        case autofs_ptype_missing_direct:
        case autofs_ptype_expire_direct:
        {
-               struct autofs_v5_packet *packet = &pkt.v5_packet;
+               struct autofs_v5_packet *packet = &pkt.v5_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->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;
@@ -152,8 +166,19 @@ static void autofs4_notify_daemon(struct autofs_sb_info *sbi,
                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,
@@ -169,7 +194,7 @@ 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;
        }
@@ -189,58 +214,55 @@ static int autofs4_getpath(struct autofs_sb_info *sbi,
 }
 
 static struct autofs_wait_queue *
-autofs4_find_wait(struct autofs_sb_info *sbi,
-                 char *name, unsigned int hash, unsigned int len)
+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->hash == hash &&
-                   wq->len == len &&
-                   wq->name && !memcmp(wq->name, name, len))
+               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;
 }
 
-int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
-               enum autofs_notify notify)
+/*
+ * 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_info *ino;
        struct autofs_wait_queue *wq;
-       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)
-               return -ENOENT;
-       
-       name = kmalloc(NAME_MAX + 1, GFP_KERNEL);
-       if (!name)
-               return -ENOMEM;
+       struct autofs_info *ino;
 
-       /* 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;
-               }
+       /* Wait in progress, continue; */
+       wq = autofs4_find_wait(sbi, qstr);
+       if (wq) {
+               *wait = wq;
+               return 1;
        }
-       hash = full_name_hash(name, len);
 
-       if (mutex_lock_interruptible(&sbi->wq_mutex)) {
-               kfree(name);
-               return -EINTR;
-       }
+       *wait = NULL;
 
-       wq = autofs4_find_wait(sbi, name, hash, len);
+       /* If we don't yet have any info this is a new request */
        ino = autofs4_dentry_ino(dentry);
-       if (!wq && ino && notify == NFY_NONE) {
+       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.
@@ -251,13 +273,14 @@ int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
                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);
+                       if (mutex_lock_interruptible(&sbi->wq_mutex))
                                return -EINTR;
+
+                       wq = autofs4_find_wait(sbi, qstr);
+                       if (wq) {
+                               *wait = wq;
+                               return 1;
                        }
-                       wq = autofs4_find_wait(sbi, name, hash, len);
-                       if (wq)
-                               break;
                }
 
                /*
@@ -265,18 +288,90 @@ int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
                 * 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 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 status, ret, type;
+
+       /* In catatonic mode, we don't wait for nobody */
+       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;
+
+       /* 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 (mutex_lock_interruptible(&sbi->wq_mutex)) {
+               kfree(qstr.name);
+               return -EINTR;
+       }
+
+       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) {
                /* Create a new wait queue */
                wq = kmalloc(sizeof(struct autofs_wait_queue),GFP_KERNEL);
                if (!wq) {
-                       kfree(name);
+                       kfree(qstr.name);
                        mutex_unlock(&sbi->wq_mutex);
                        return -ENOMEM;
                }
@@ -287,17 +382,15 @@ 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->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->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);
+               wq->wait_ctr = 2;
                mutex_unlock(&sbi->wq_mutex);
 
                if (sbi->version < 5) {
@@ -307,38 +400,35 @@ int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
                                type = autofs_ptype_expire_multi;
                } else {
                        if (notify == NFY_MOUNT)
-                               type = (sbi->type & AUTOFS_TYPE_DIRECT) ?
+                               type = autofs_type_trigger(sbi->type) ?
                                        autofs_ptype_missing_direct :
                                         autofs_ptype_missing_indirect;
                        else
-                               type = (sbi->type & AUTOFS_TYPE_DIRECT) ?
+                               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);
+                       (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 {
-               atomic_inc(&wq->wait_ctr);
+               wq->wait_ctr++;
                mutex_unlock(&sbi->wq_mutex);
-               kfree(name);
+               kfree(qstr.name);
                DPRINTK("existing wait id = 0x%08lx, name = %.*s, nfy=%d",
-                       (unsigned long) wq->wait_queue_token, wq->len, wq->name, notify);
+                       (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;
-               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;
@@ -349,7 +439,7 @@ int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
                recalc_sigpending();
                spin_unlock_irqrestore(&current->sighand->siglock, irqflags);
 
-               wait_event_interruptible(wq->queue, wq->name == NULL);
+               wait_event_interruptible(wq->queue, wq->name.name == NULL);
 
                spin_lock_irqsave(&current->sighand->siglock, irqflags);
                current->blocked = oldset;
@@ -361,9 +451,45 @@ int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
 
        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;
 }
@@ -374,7 +500,7 @@ 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) {
+       for (wql = &sbi->queues; (wq = *wql) != NULL; wql = &wq->next) {
                if (wq->wait_queue_token == wait_queue_token)
                        break;
        }
@@ -385,16 +511,13 @@ int autofs4_wait_release(struct autofs_sb_info *sbi, autofs_wqt_t wait_queue_tok
        }
 
        *wql = wq->next;        /* Unlink from chain */
-       mutex_unlock(&sbi->wq_mutex);
-       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;
 }