diff options
Diffstat (limited to 'fs/autofs/waitq.c')
| -rw-r--r-- | fs/autofs/waitq.c | 205 |
1 files changed, 0 insertions, 205 deletions
diff --git a/fs/autofs/waitq.c b/fs/autofs/waitq.c deleted file mode 100644 index be46805..0000000 --- a/fs/autofs/waitq.c +++ /dev/null @@ -1,205 +0,0 @@ -/* -*- linux-c -*- --------------------------------------------------------- * - * - * linux/fs/autofs/waitq.c - * - * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved - * - * 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 autofs_next_wait_queue = 1; - -/* These are the signals we allow interrupting a pending mount */ -#define SHUTDOWN_SIGS (sigmask(SIGKILL) | sigmask(SIGINT) | sigmask(SIGQUIT)) - -void autofs_catatonic_mode(struct autofs_sb_info *sbi) -{ - struct autofs_wait_queue *wq, *nwq; - - DPRINTK(("autofs: entering catatonic mode\n")); - - 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(&wq->queue); - wq = nwq; - } - fput(sbi->pipe); /* Close the pipe */ - sbi->pipe = NULL; - autofs_hash_dputall(&sbi->dirhash); /* Remove all dentry pointers */ -} - -static int autofs_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(¤t->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(¤t->sighand->siglock, flags); - sigdelset(¤t->pending.signal, SIGPIPE); - recalc_sigpending(); - spin_unlock_irqrestore(¤t->sighand->siglock, flags); - } - - return (bytes > 0); -} - -static void autofs_notify_daemon(struct autofs_sb_info *sbi, struct autofs_wait_queue *wq) -{ - struct autofs_packet_missing pkt; - - DPRINTK(("autofs_wait: wait id = 0x%08lx, name = ", wq->wait_queue_token)); - autofs_say(wq->name,wq->len); - - memset(&pkt,0,sizeof pkt); /* For security reasons */ - - pkt.hdr.proto_version = AUTOFS_PROTO_VERSION; - pkt.hdr.type = autofs_ptype_missing; - pkt.wait_queue_token = wq->wait_queue_token; - pkt.len = wq->len; - memcpy(pkt.name, wq->name, pkt.len); - pkt.name[pkt.len] = '\0'; - - if ( autofs_write(sbi->pipe,&pkt,sizeof(struct autofs_packet_missing)) ) - autofs_catatonic_mode(sbi); -} - -int autofs_wait(struct autofs_sb_info *sbi, struct qstr *name) -{ - struct autofs_wait_queue *wq; - int status; - - /* In catatonic mode, we don't wait for nobody */ - if ( sbi->catatonic ) - return -ENOENT; - - /* We shouldn't be able to get here, but just in case */ - if ( name->len > NAME_MAX ) - return -ENOENT; - - 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 ( !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); - return -ENOMEM; - } - wq->wait_queue_token = autofs_next_wait_queue++; - 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; - - /* autofs_notify_daemon() may block */ - wq->wait_ctr = 2; - autofs_notify_daemon(sbi,wq); - } else - wq->wait_ctr++; - - /* 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 ) { - /* Block all but "shutdown" signals while waiting */ - sigset_t sigmask; - - siginitsetinv(&sigmask, SHUTDOWN_SIGS); - sigprocmask(SIG_BLOCK, &sigmask, &sigmask); - - interruptible_sleep_on(&wq->queue); - - sigprocmask(SIG_SETMASK, &sigmask, NULL); - } else { - DPRINTK(("autofs_wait: skipped sleeping\n")); - } - - status = wq->status; - - if ( ! --wq->wait_ctr ) /* Are we the last process to need status? */ - kfree(wq); - - return status; -} - - -int autofs_wait_release(struct autofs_sb_info *sbi, autofs_wqt_t wait_queue_token, int status) -{ - struct autofs_wait_queue *wq, **wql; - - for (wql = &sbi->queues; (wq = *wql) != NULL; wql = &wq->next) { - if ( wq->wait_queue_token == wait_queue_token ) - break; - } - if ( !wq ) - return -EINVAL; - - *wql = wq->next; /* Unlink from chain */ - kfree(wq->name); - wq->name = NULL; /* Do not wait on this queue */ - - wq->status = status; - - if ( ! --wq->wait_ctr ) /* Is anyone still waiting for this guy? */ - kfree(wq); - else - wake_up(&wq->queue); - - return 0; -} - |