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root/fs/autofs/inode.c

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DEFINITIONS

This source file includes following definitions.
  1. autofs_kill_sb
  2. parse_options
  3. autofs_fill_super
  4. autofs_iget

/* -*- linux-c -*- --------------------------------------------------------- *
 *
 * linux/fs/autofs/inode.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/kernel.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/file.h>
#include <linux/parser.h>
#include <linux/bitops.h>
#include <linux/magic.h>
#include "autofs_i.h"
#include <linux/module.h>

void autofs_kill_sb(struct super_block *sb)
{
        struct autofs_sb_info *sbi = autofs_sbi(sb);
        unsigned int n;

        /*
         * In the event of a failure in get_sb_nodev the superblock
         * info is not present so nothing else has been setup, so
         * just call kill_anon_super when we are called from
         * deactivate_super.
         */
        if (!sbi)
                goto out_kill_sb;

        if (!sbi->catatonic)
                autofs_catatonic_mode(sbi); /* Free wait queues, close pipe */

        put_pid(sbi->oz_pgrp);

        autofs_hash_nuke(sbi);
        for (n = 0; n < AUTOFS_MAX_SYMLINKS; n++) {
                if (test_bit(n, sbi->symlink_bitmap))
                        kfree(sbi->symlink[n].data);
        }

        kfree(sb->s_fs_info);

out_kill_sb:
        DPRINTK(("autofs: shutting down\n"));
        kill_anon_super(sb);
}

static const struct super_operations autofs_sops = {
        .statfs         = simple_statfs,
        .show_options   = generic_show_options,
};

enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto};

static const match_table_t autofs_tokens = {
        {Opt_fd, "fd=%u"},
        {Opt_uid, "uid=%u"},
        {Opt_gid, "gid=%u"},
        {Opt_pgrp, "pgrp=%u"},
        {Opt_minproto, "minproto=%u"},
        {Opt_maxproto, "maxproto=%u"},
        {Opt_err, NULL}
};

static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid,
                pid_t *pgrp, int *minproto, int *maxproto)
{
        char *p;
        substring_t args[MAX_OPT_ARGS];
        int option;

        *uid = current->uid;
        *gid = current->gid;
        *pgrp = task_pgrp_nr(current);

        *minproto = *maxproto = AUTOFS_PROTO_VERSION;

        *pipefd = -1;

        if (!options)
                return 1;

        while ((p = strsep(&options, ",")) != NULL) {
                int token;
                if (!*p)
                        continue;

                token = match_token(p, autofs_tokens, args);
                switch (token) {
                case Opt_fd:
                        if (match_int(&args[0], &option))
                                return 1;
                        *pipefd = option;
                        break;
                case Opt_uid:
                        if (match_int(&args[0], &option))
                                return 1;
                        *uid = option;
                        break;
                case Opt_gid:
                        if (match_int(&args[0], &option))
                                return 1;
                        *gid = option;
                        break;
                case Opt_pgrp:
                        if (match_int(&args[0], &option))
                                return 1;
                        *pgrp = option;
                        break;
                case Opt_minproto:
                        if (match_int(&args[0], &option))
                                return 1;
                        *minproto = option;
                        break;
                case Opt_maxproto:
                        if (match_int(&args[0], &option))
                                return 1;
                        *maxproto = option;
                        break;
                default:
                        return 1;
                }
        }
        return (*pipefd < 0);
}

int autofs_fill_super(struct super_block *s, void *data, int silent)
{
        struct inode * root_inode;
        struct dentry * root;
        struct file * pipe;
        int pipefd;
        struct autofs_sb_info *sbi;
        int minproto, maxproto;
        pid_t pgid;

        save_mount_options(s, data);

        sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
        if (!sbi)
                goto fail_unlock;
        DPRINTK(("autofs: starting up, sbi = %p\n",sbi));

        s->s_fs_info = sbi;
        sbi->magic = AUTOFS_SBI_MAGIC;
        sbi->pipe = NULL;
        sbi->catatonic = 1;
        sbi->exp_timeout = 0;
        autofs_initialize_hash(&sbi->dirhash);
        sbi->queues = NULL;
        memset(sbi->symlink_bitmap, 0, sizeof(long)*AUTOFS_SYMLINK_BITMAP_LEN);
        sbi->next_dir_ino = AUTOFS_FIRST_DIR_INO;
        s->s_blocksize = 1024;
        s->s_blocksize_bits = 10;
        s->s_magic = AUTOFS_SUPER_MAGIC;
        s->s_op = &autofs_sops;
        s->s_time_gran = 1;
        sbi->sb = s;

        root_inode = autofs_iget(s, AUTOFS_ROOT_INO);
        if (IS_ERR(root_inode))
                goto fail_free;
        root = d_alloc_root(root_inode);
        pipe = NULL;

        if (!root)
                goto fail_iput;

        /* Can this call block?  - WTF cares? s is locked. */
        if (parse_options(data, &pipefd, &root_inode->i_uid,
                                &root_inode->i_gid, &pgid, &minproto,
                                &maxproto)) {
                printk("autofs: called with bogus options\n");
                goto fail_dput;
        }

        /* Couldn't this be tested earlier? */
        if (minproto > AUTOFS_PROTO_VERSION ||
             maxproto < AUTOFS_PROTO_VERSION) {
                printk("autofs: kernel does not match daemon version\n");
                goto fail_dput;
        }

        DPRINTK(("autofs: pipe fd = %d, pgrp = %u\n", pipefd, pgid));
        sbi->oz_pgrp = find_get_pid(pgid);

        if (!sbi->oz_pgrp) {
                printk("autofs: could not find process group %d\n", pgid);
                goto fail_dput;
        }

        pipe = fget(pipefd);
        
        if (!pipe) {
                printk("autofs: could not open pipe file descriptor\n");
                goto fail_put_pid;
        }

        if (!pipe->f_op || !pipe->f_op->write)
                goto fail_fput;
        sbi->pipe = pipe;
        sbi->catatonic = 0;

        /*
         * Success! Install the root dentry now to indicate completion.
         */
        s->s_root = root;
        return 0;

fail_fput:
        printk("autofs: pipe file descriptor does not contain proper ops\n");
        fput(pipe);
fail_put_pid:
        put_pid(sbi->oz_pgrp);
fail_dput:
        dput(root);
        goto fail_free;
fail_iput:
        printk("autofs: get root dentry failed\n");
        iput(root_inode);
fail_free:
        kfree(sbi);
        s->s_fs_info = NULL;
fail_unlock:
        return -EINVAL;
}

struct inode *autofs_iget(struct super_block *sb, unsigned long ino)
{
        unsigned int n;
        struct autofs_sb_info *sbi = autofs_sbi(sb);
        struct inode *inode;

        inode = iget_locked(sb, ino);
        if (!inode)
                return ERR_PTR(-ENOMEM);
        if (!(inode->i_state & I_NEW))
                return inode;

        /* Initialize to the default case (stub directory) */

        inode->i_op = &simple_dir_inode_operations;
        inode->i_fop = &simple_dir_operations;
        inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO;
        inode->i_nlink = 2;
        inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
        inode->i_blocks = 0;

        if (ino == AUTOFS_ROOT_INO) {
                inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO | S_IWUSR;
                inode->i_op = &autofs_root_inode_operations;
                inode->i_fop = &autofs_root_operations;
                inode->i_uid = inode->i_gid = 0; /* Changed in read_super */
                goto done;
        } 
        
        inode->i_uid = inode->i_sb->s_root->d_inode->i_uid;
        inode->i_gid = inode->i_sb->s_root->d_inode->i_gid;
        
        if (ino >= AUTOFS_FIRST_SYMLINK && ino < AUTOFS_FIRST_DIR_INO) {
                /* Symlink inode - should be in symlink list */
                struct autofs_symlink *sl;

                n = ino - AUTOFS_FIRST_SYMLINK;
                if (n >= AUTOFS_MAX_SYMLINKS || !test_bit(n,sbi->symlink_bitmap)) {
                        printk("autofs: Looking for bad symlink inode %u\n", (unsigned int) ino);
                        goto done;
                }
                
                inode->i_op = &autofs_symlink_inode_operations;
                sl = &sbi->symlink[n];
                inode->i_private = sl;
                inode->i_mode = S_IFLNK | S_IRWXUGO;
                inode->i_mtime.tv_sec = inode->i_ctime.tv_sec = sl->mtime;
                inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0;
                inode->i_size = sl->len;
                inode->i_nlink = 1;
        }

done:
        unlock_new_inode(inode);
        return inode;
}

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