scoutos / prex-0.9.0 / usr / server / fs / vfs / vfs_task.c @ 03e9c04a
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/*-
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* Copyright (c) 2007, Kohsuke Ohtani All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the author nor the names of any co-contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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/*
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* vfs_task.c - Routines to manage the per task data.
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*/
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#include <sys/prex.h> |
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#include <sys/list.h> |
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#include <limits.h> |
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#include <stdlib.h> |
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#include <string.h> |
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#include <stdio.h> |
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#include <errno.h> |
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#include "vfs.h" |
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#define TASK_MAXBUCKETS 32 /* number of task hash buckets */ |
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#define TASKHASH(x) (int)((x) & (TASK_MAXBUCKETS - 1)) |
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/*
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* Hash table for task.
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*/
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static struct list task_table[TASK_MAXBUCKETS]; |
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/*
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* Global lock for task access.
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*/
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#if CONFIG_FS_THREADS > 1 |
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static mutex_t task_lock = MUTEX_INITIALIZER;
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#define TASK_LOCK() mutex_lock(&task_lock)
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#define TASK_UNLOCK() mutex_unlock(&task_lock)
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#else
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#define TASK_LOCK()
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#define TASK_UNLOCK()
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#endif
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/*
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* Convert task ID to a task structure.
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* Returns locked task. Caller must unlock it after using it.
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*/
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struct task *
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task_lookup(task_t task) |
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{ |
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list_t head, n; |
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struct task *t;
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if (task == TASK_NULL)
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return NULL; |
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TASK_LOCK(); |
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head = &task_table[TASKHASH(task)]; |
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for (n = list_first(head); n != head; n = list_next(n)) {
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t = list_entry(n, struct task, t_link);
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ASSERT(t->t_taskid); |
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if (t->t_taskid == task) {
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TASK_UNLOCK(); |
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mutex_lock(&t->t_lock); |
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return t;
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} |
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} |
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TASK_UNLOCK(); |
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/* Not found */
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return NULL; |
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} |
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/*
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* Allocate new task.
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*/
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int
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task_alloc(task_t task, struct task **pt)
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{ |
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struct task *t;
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/* Check if specified task already exists. */
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if (task_lookup(task) != NULL) |
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return EINVAL;
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if (!(t = malloc(sizeof(struct task)))) |
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return ENOMEM;
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memset(t, 0, sizeof(struct task)); |
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t->t_taskid = task; |
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strlcpy(t->t_cwd, "/", sizeof(t->t_cwd)); |
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mutex_init(&t->t_lock); |
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TASK_LOCK(); |
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list_insert(&task_table[TASKHASH(task)], &t->t_link); |
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TASK_UNLOCK(); |
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*pt = t; |
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return 0; |
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} |
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/*
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* Free task and related resource.
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*/
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void
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task_free(struct task *t)
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{ |
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TASK_LOCK(); |
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list_remove(&t->t_link); |
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mutex_unlock(&t->t_lock); |
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mutex_destroy(&t->t_lock); |
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free(t); |
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TASK_UNLOCK(); |
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} |
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/*
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* Set task id of the specified task.
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*/
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void
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task_setid(struct task *t, task_t task)
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{ |
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TASK_LOCK(); |
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list_remove(&t->t_link); |
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t->t_taskid = task; |
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list_insert(&task_table[TASKHASH(task)], &t->t_link); |
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TASK_UNLOCK(); |
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} |
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/*
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* Unlock task.
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*/
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void
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task_unlock(struct task *t)
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{ |
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mutex_unlock(&t->t_lock); |
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} |
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/*
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* Convert a file descriptor into a pointer
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* to a file structre.
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*/
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file_t |
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task_getfp(struct task *t, int fd) |
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{ |
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if (fd < 0 || fd >= OPEN_MAX) |
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return NULL; |
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return t->t_ofile[fd];
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} |
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/*
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* Set file pointer for task/fd pair.
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*/
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void
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task_setfp(struct task *t, int fd, file_t fp) |
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{ |
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t->t_ofile[fd] = fp; |
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} |
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/*
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* Get new file descriptor in the task.
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* Returns -1 if there is no empty slot.
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*/
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int
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task_newfd(struct task *t)
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{ |
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int fd;
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/*
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* Find the smallest empty slot in the fd array.
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*/
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for (fd = 0; fd < OPEN_MAX; fd++) { |
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if (t->t_ofile[fd] == NULL) |
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break;
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} |
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if (fd == OPEN_MAX)
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return -1; /* slot full */ |
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return fd;
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} |
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/*
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* Delete a file descriptor.
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*/
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void
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task_delfd(struct task *t, int fd) |
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{ |
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t->t_ofile[fd] = NULL;
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} |
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/*
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* Convert to full path from the cwd of task and path.
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* @t: task structure
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* @path: target path
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* @full: full path to be returned
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* @acc: access mode
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*/
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int
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task_conv(struct task *t, char *path, int acc, char *full) |
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{ |
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char *src, *tgt, *p, *end, *cwd;
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size_t len = 0;
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cwd = t->t_cwd; |
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path[PATH_MAX - 1] = '\0'; |
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len = strlen(path); |
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if (len >= PATH_MAX)
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return ENAMETOOLONG;
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if (strlen(cwd) + len >= PATH_MAX)
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return ENAMETOOLONG;
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src = path; |
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tgt = full; |
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end = src + len; |
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if (path[0] == '/') { |
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*tgt++ = *src++; |
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len++; |
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} else {
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strlcpy(full, cwd, PATH_MAX); |
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len = strlen(cwd); |
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tgt += len; |
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if (len > 1 && path[0] != '.') { |
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*tgt = '/';
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tgt++; |
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len++; |
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} |
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} |
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while (*src) {
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p = src; |
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while (*p != '/' && *p != '\0') |
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p++; |
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*p = '\0';
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if (!strcmp(src, "..")) { |
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if (len >= 2) { |
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len -= 2;
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tgt -= 2; /* skip previous '/' */ |
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while (*tgt != '/') { |
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tgt--; |
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len--; |
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} |
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if (len == 0) { |
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tgt++; |
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len++; |
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} |
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} |
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} else if (!strcmp(src, ".")) { |
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/* Ignore "." */
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} else {
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while (*src != '\0') { |
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*tgt++ = *src++; |
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len++; |
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} |
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} |
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if (p == end)
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break;
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if (len > 0 && *(tgt - 1) != '/') { |
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*tgt++ = '/';
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len++; |
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} |
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src = p + 1;
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} |
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*tgt = '\0';
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/* Check if the client task has required permission */
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return sec_file_permission(t->t_taskid, full, acc);
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} |
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#ifdef DEBUG_VFS
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void
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task_dump(void)
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{ |
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list_t head, n; |
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struct task *t;
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int i;
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TASK_LOCK(); |
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dprintf("Dump file data\n");
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dprintf(" task opens cwd\n");
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dprintf(" -------- ------- ------------------------------\n");
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for (i = 0; i < TASK_MAXBUCKETS; i++) { |
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head = &task_table[i]; |
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for (n = list_first(head); n != head; n = list_next(n)) {
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t = list_entry(n, struct task, t_link);
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dprintf(" %08x %7x %s\n", (int)t->t_taskid, t->t_nopens, |
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t->t_cwd); |
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} |
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} |
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dprintf("\n");
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TASK_UNLOCK(); |
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} |
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#endif
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void
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task_init(void)
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{ |
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int i;
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for (i = 0; i < TASK_MAXBUCKETS; i++) |
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list_init(&task_table[i]); |
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} |