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, 303 insertions, 0 deletions

diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c
new file mode 100644
index 000000000000..1ab24a662e09
--- /dev/null
+++ b/fs/autofs4/waitq.c
@@ -0,0 +1,303 @@
+/* -*- c -*- --------------------------------------------------------------- *
+ *
+ * linux/fs/autofs/waitq.c
+ *
+ *  Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
+ *  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
+ * option, any later version, incorporated herein by reference.
+ *
+ * ------------------------------------------------------------------------- */
+
+#include <linux/slab.h>
+#include <linux/time.h>
+#include <linux/signal.h>
+#include <linux/file.h>
+#include "autofs_i.h"
+
+/* We make this a static variable rather than a part of the superblock; it
+   is better if we don't reassign numbers easily even across filesystems */
+static autofs_wqt_t autofs4_next_wait_queue = 1;
+
+/* These are the signals we allow interrupting a pending mount */
+#define SHUTDOWN_SIGS   (sigmask(SIGKILL) | sigmask(SIGINT) | sigmask(SIGQUIT))
+
+void autofs4_catatonic_mode(struct autofs_sb_info *sbi)
+{
+        struct autofs_wait_queue *wq, *nwq;
+
+        DPRINTK("entering catatonic mode");
+
+        sbi->catatonic = 1;
+        wq = sbi->queues;
+        sbi->queues = NULL;     /* Erase all wait queues */
+        while ( wq ) {
+                nwq = wq->next;
+                wq->status = -ENOENT; /* Magic is gone - report failure */
+                kfree(wq->name);
+                wq->name = NULL;
+                wake_up_interruptible(&wq->queue);
+                wq = nwq;
+        }
+        if (sbi->pipe) {
+                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)
+{
+        unsigned long sigpipe, flags;
+        mm_segment_t fs;
+        const char *data = (const char *)addr;
+        ssize_t wr = 0;
+
+        /** WARNING: this is not safe for writing more than PIPE_BUF bytes! **/
+
+        sigpipe = sigismember(&current->pending.signal, SIGPIPE);
+
+        /* Save pointer to user space and point back to kernel space */
+        fs = get_fs();
+        set_fs(KERNEL_DS);
+
+        while (bytes &&
+               (wr = file->f_op->write(file,data,bytes,&file->f_pos)) > 0) {
+                data += wr;
+                bytes -= wr;
+        }
+
+        set_fs(fs);
+
+        /* Keep the currently executing process from receiving a
+           SIGPIPE unless it was already supposed to get one */
+        if (wr == -EPIPE && !sigpipe) {
+                spin_lock_irqsave(&current->sighand->siglock, flags);
+                sigdelset(&current->pending.signal, SIGPIPE);
+                recalc_sigpending();
+                spin_unlock_irqrestore(&current->sighand->siglock, flags);
+        }
+
+        return (bytes > 0);
+}
+        
+static void autofs4_notify_daemon(struct autofs_sb_info *sbi,
+                                 struct autofs_wait_queue *wq,
+                                 int type)
+{
+        union autofs_packet_union pkt;
+        size_t pktsz;
+
+        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) {
+                struct autofs_packet_missing *mp = &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;
+
+                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 {
+                printk("autofs4_notify_daemon: bad type %d!\n", type);
+                return;
+        }
+
+        if (autofs4_write(sbi->pipe, &pkt, pktsz))
+                autofs4_catatonic_mode(sbi);
+}
+
+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;
+}
+
+int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
+                enum autofs_notify notify)
+{
+        struct autofs_wait_queue *wq;
+        char *name;
+        int len, status;
+
+        /* 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;
+
+        len = autofs4_getpath(sbi, dentry, &name);
+        if (!len) {
+                kfree(name);
+                return -ENOENT;
+        }
+
+        if (down_interruptible(&sbi->wq_sem)) {
+                kfree(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;
+        }
+
+        if ( !wq ) {
+                /* Create a new wait queue */
+                wq = kmalloc(sizeof(struct autofs_wait_queue),GFP_KERNEL);
+                if ( !wq ) {
+                        kfree(name);
+                        up(&sbi->wq_sem);
+                        return -ENOMEM;
+                }
+
+                wq->wait_queue_token = autofs4_next_wait_queue;
+                if (++autofs4_next_wait_queue == 0)
+                        autofs4_next_wait_queue = 1;
+                wq->next = sbi->queues;
+                sbi->queues = wq;
+                init_waitqueue_head(&wq->queue);
+                wq->hash = dentry->d_name.hash;
+                wq->name = name;
+                wq->len = len;
+                wq->status = -EINTR; /* Status return if interrupted */
+                atomic_set(&wq->wait_ctr, 2);
+                up(&sbi->wq_sem);
+
+                DPRINTK("new wait id = 0x%08lx, name = %.*s, nfy=%d",
+                        (unsigned long) wq->wait_queue_token, wq->len, wq->name, notify);
+                /* autofs4_notify_daemon() may block */
+                if (notify != NFY_NONE) {
+                        autofs4_notify_daemon(sbi,wq, 
+                                        notify == NFY_MOUNT ?
+                                                  autofs_ptype_missing :
+                                                  autofs_ptype_expire_multi);
+                }
+        } 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);
+        }
+
+        /* 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 ) {
+                /* Block all but "shutdown" signals while waiting */
+                sigset_t oldset;
+                unsigned long irqflags;
+
+                spin_lock_irqsave(&current->sighand->siglock, irqflags);
+                oldset = current->blocked;
+                siginitsetinv(&current->blocked, SHUTDOWN_SIGS & ~oldset.sig[0]);
+                recalc_sigpending();
+                spin_unlock_irqrestore(&current->sighand->siglock, irqflags);
+
+                wait_event_interruptible(wq->queue, wq->name == NULL);
+
+                spin_lock_irqsave(&current->sighand->siglock, irqflags);
+                current->blocked = oldset;
+                recalc_sigpending();
+                spin_unlock_irqrestore(&current->sighand->siglock, irqflags);
+        } else {
+                DPRINTK("skipped sleeping");
+        }
+
+        status = wq->status;
+
+        /* Are we the last process to need status? */
+        if (atomic_dec_and_test(&wq->wait_ctr))
+                kfree(wq);
+
+        return status;
+}
+
+
+int autofs4_wait_release(struct autofs_sb_info *sbi, autofs_wqt_t wait_queue_token, int 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 )
+                        break;
+        }
+
+        if ( !wq ) {
+                up(&sbi->wq_sem);
+                return -EINVAL;
+        }
+
+        *wql = wq->next;        /* Unlink from chain */
+        up(&sbi->wq_sem);
+        kfree(wq->name);
+        wq->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? */
+                kfree(wq);
+        else
+                wake_up_interruptible(&wq->queue);
+
+        return 0;
+}
+