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linux-sg2042/fs/autofs4/inode.c

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C
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/* -*- c -*- --------------------------------------------------------------- *
*
* linux/fs/autofs/inode.c
*
* Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
* Copyright 2005-2006 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/kernel.h>
#include <linux/slab.h>
#include <linux/file.h>
#include <linux/seq_file.h>
#include <linux/pagemap.h>
#include <linux/parser.h>
#include <linux/bitops.h>
#include <linux/smp_lock.h>
#include "autofs_i.h"
#include <linux/module.h>
static void ino_lnkfree(struct autofs_info *ino)
{
kfree(ino->u.symlink);
ino->u.symlink = NULL;
}
struct autofs_info *autofs4_init_ino(struct autofs_info *ino,
struct autofs_sb_info *sbi, mode_t mode)
{
int reinit = 1;
if (ino == NULL) {
reinit = 0;
ino = kmalloc(sizeof(*ino), GFP_KERNEL);
}
if (ino == NULL)
return NULL;
ino->flags = 0;
ino->mode = mode;
ino->inode = NULL;
ino->dentry = NULL;
ino->size = 0;
ino->last_used = jiffies;
atomic_set(&ino->count, 0);
ino->sbi = sbi;
if (reinit && ino->free)
(ino->free)(ino);
memset(&ino->u, 0, sizeof(ino->u));
ino->free = NULL;
if (S_ISLNK(mode))
ino->free = ino_lnkfree;
return ino;
}
void autofs4_free_ino(struct autofs_info *ino)
{
struct autofs_info *p_ino;
if (ino->dentry) {
ino->dentry->d_fsdata = NULL;
if (ino->dentry->d_inode) {
struct dentry *parent = ino->dentry->d_parent;
if (atomic_dec_and_test(&ino->count)) {
p_ino = autofs4_dentry_ino(parent);
if (p_ino && parent != ino->dentry)
atomic_dec(&p_ino->count);
}
dput(ino->dentry);
}
ino->dentry = NULL;
}
if (ino->free)
(ino->free)(ino);
kfree(ino);
}
/*
* Deal with the infamous "Busy inodes after umount ..." message.
*
* Clean up the dentry tree. This happens with autofs if the user
* space program goes away due to a SIGKILL, SIGSEGV etc.
*/
static void autofs4_force_release(struct autofs_sb_info *sbi)
{
struct dentry *this_parent = sbi->root;
struct list_head *next;
spin_lock(&dcache_lock);
repeat:
next = this_parent->d_subdirs.next;
resume:
while (next != &this_parent->d_subdirs) {
struct dentry *dentry = list_entry(next, struct dentry, d_u.d_child);
/* Negative dentry - don`t care */
if (!simple_positive(dentry)) {
next = next->next;
continue;
}
if (!list_empty(&dentry->d_subdirs)) {
this_parent = dentry;
goto repeat;
}
next = next->next;
spin_unlock(&dcache_lock);
DPRINTK("dentry %p %.*s",
dentry, (int)dentry->d_name.len, dentry->d_name.name);
dput(dentry);
spin_lock(&dcache_lock);
}
if (this_parent != sbi->root) {
struct dentry *dentry = this_parent;
next = this_parent->d_u.d_child.next;
this_parent = this_parent->d_parent;
spin_unlock(&dcache_lock);
DPRINTK("parent dentry %p %.*s",
dentry, (int)dentry->d_name.len, dentry->d_name.name);
dput(dentry);
spin_lock(&dcache_lock);
goto resume;
}
spin_unlock(&dcache_lock);
dput(sbi->root);
sbi->root = NULL;
shrink_dcache_sb(sbi->sb);
return;
}
static void autofs4_put_super(struct super_block *sb)
{
struct autofs_sb_info *sbi = autofs4_sbi(sb);
sb->s_fs_info = NULL;
if ( !sbi->catatonic )
autofs4_catatonic_mode(sbi); /* Free wait queues, close pipe */
/* Clean up and release dangling references */
autofs4_force_release(sbi);
kfree(sbi);
DPRINTK("shutting down");
}
static int autofs4_show_options(struct seq_file *m, struct vfsmount *mnt)
{
struct autofs_sb_info *sbi = autofs4_sbi(mnt->mnt_sb);
if (!sbi)
return 0;
seq_printf(m, ",fd=%d", sbi->pipefd);
seq_printf(m, ",pgrp=%d", sbi->oz_pgrp);
seq_printf(m, ",timeout=%lu", sbi->exp_timeout/HZ);
seq_printf(m, ",minproto=%d", sbi->min_proto);
seq_printf(m, ",maxproto=%d", sbi->max_proto);
if (sbi->type & AUTOFS_TYPE_OFFSET)
seq_printf(m, ",offset");
else if (sbi->type & AUTOFS_TYPE_DIRECT)
seq_printf(m, ",direct");
else
seq_printf(m, ",indirect");
return 0;
}
static struct super_operations autofs4_sops = {
.put_super = autofs4_put_super,
.statfs = simple_statfs,
.show_options = autofs4_show_options,
};
enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto,
Opt_indirect, Opt_direct, Opt_offset};
static match_table_t 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_indirect, "indirect"},
{Opt_direct, "direct"},
{Opt_offset, "offset"},
{Opt_err, NULL}
};
static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid,
pid_t *pgrp, unsigned int *type,
int *minproto, int *maxproto)
{
char *p;
substring_t args[MAX_OPT_ARGS];
int option;
*uid = current->uid;
*gid = current->gid;
*pgrp = process_group(current);
*minproto = AUTOFS_MIN_PROTO_VERSION;
*maxproto = AUTOFS_MAX_PROTO_VERSION;
*pipefd = -1;
if (!options)
return 1;
while ((p = strsep(&options, ",")) != NULL) {
int token;
if (!*p)
continue;
token = match_token(p, tokens, args);
switch (token) {
case Opt_fd:
if (match_int(args, pipefd))
return 1;
break;
case Opt_uid:
if (match_int(args, &option))
return 1;
*uid = option;
break;
case Opt_gid:
if (match_int(args, &option))
return 1;
*gid = option;
break;
case Opt_pgrp:
if (match_int(args, &option))
return 1;
*pgrp = option;
break;
case Opt_minproto:
if (match_int(args, &option))
return 1;
*minproto = option;
break;
case Opt_maxproto:
if (match_int(args, &option))
return 1;
*maxproto = option;
break;
case Opt_indirect:
*type = AUTOFS_TYPE_INDIRECT;
break;
case Opt_direct:
*type = AUTOFS_TYPE_DIRECT;
break;
case Opt_offset:
*type = AUTOFS_TYPE_DIRECT | AUTOFS_TYPE_OFFSET;
break;
default:
return 1;
}
}
return (*pipefd < 0);
}
static struct autofs_info *autofs4_mkroot(struct autofs_sb_info *sbi)
{
struct autofs_info *ino;
ino = autofs4_init_ino(NULL, sbi, S_IFDIR | 0755);
if (!ino)
return NULL;
return ino;
}
static struct dentry_operations autofs4_sb_dentry_operations = {
.d_release = autofs4_dentry_release,
};
int autofs4_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;
struct autofs_info *ino;
sbi = (struct autofs_sb_info *) kmalloc(sizeof(*sbi), GFP_KERNEL);
if ( !sbi )
goto fail_unlock;
DPRINTK("starting up, sbi = %p",sbi);
memset(sbi, 0, sizeof(*sbi));
s->s_fs_info = sbi;
sbi->magic = AUTOFS_SBI_MAGIC;
sbi->root = NULL;
sbi->pipefd = -1;
sbi->catatonic = 0;
sbi->exp_timeout = 0;
sbi->oz_pgrp = process_group(current);
sbi->sb = s;
sbi->version = 0;
sbi->sub_version = 0;
sbi->type = 0;
sbi->min_proto = 0;
sbi->max_proto = 0;
mutex_init(&sbi->wq_mutex);
spin_lock_init(&sbi->fs_lock);
sbi->queues = NULL;
s->s_blocksize = 1024;
s->s_blocksize_bits = 10;
s->s_magic = AUTOFS_SUPER_MAGIC;
s->s_op = &autofs4_sops;
s->s_time_gran = 1;
/*
* Get the root inode and dentry, but defer checking for errors.
*/
ino = autofs4_mkroot(sbi);
if (!ino)
goto fail_free;
root_inode = autofs4_get_inode(s, ino);
if (!root_inode)
goto fail_ino;
root = d_alloc_root(root_inode);
if (!root)
goto fail_iput;
pipe = NULL;
root->d_op = &autofs4_sb_dentry_operations;
root->d_fsdata = ino;
/* Can this call block? */
if (parse_options(data, &pipefd,
&root_inode->i_uid, &root_inode->i_gid,
&sbi->oz_pgrp, &sbi->type,
&sbi->min_proto, &sbi->max_proto)) {
printk("autofs: called with bogus options\n");
goto fail_dput;
}
root_inode->i_fop = &autofs4_root_operations;
root_inode->i_op = sbi->type & AUTOFS_TYPE_DIRECT ?
&autofs4_direct_root_inode_operations :
&autofs4_indirect_root_inode_operations;
/* Couldn't this be tested earlier? */
if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION ||
sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) {
printk("autofs: kernel does not match daemon version "
"daemon (%d, %d) kernel (%d, %d)\n",
sbi->min_proto, sbi->max_proto,
AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION);
goto fail_dput;
}
/* Establish highest kernel protocol version */
if (sbi->max_proto > AUTOFS_MAX_PROTO_VERSION)
sbi->version = AUTOFS_MAX_PROTO_VERSION;
else
sbi->version = sbi->max_proto;
sbi->sub_version = AUTOFS_PROTO_SUBVERSION;
DPRINTK("pipe fd = %d, pgrp = %u", pipefd, sbi->oz_pgrp);
pipe = fget(pipefd);
if ( !pipe ) {
printk("autofs: could not open pipe file descriptor\n");
goto fail_dput;
}
if ( !pipe->f_op || !pipe->f_op->write )
goto fail_fput;
sbi->pipe = pipe;
sbi->pipefd = pipefd;
/*
* Take a reference to the root dentry so we get a chance to
* clean up the dentry tree on umount.
* See autofs4_force_release.
*/
sbi->root = dget(root);
/*
* Success! Install the root dentry now to indicate completion.
*/
s->s_root = root;
return 0;
/*
* Failure ... clean up.
*/
fail_fput:
printk("autofs: pipe file descriptor does not contain proper ops\n");
fput(pipe);
/* fall through */
fail_dput:
dput(root);
goto fail_free;
fail_iput:
printk("autofs: get root dentry failed\n");
iput(root_inode);
fail_ino:
kfree(ino);
fail_free:
kfree(sbi);
fail_unlock:
return -EINVAL;
}
struct inode *autofs4_get_inode(struct super_block *sb,
struct autofs_info *inf)
{
struct inode *inode = new_inode(sb);
if (inode == NULL)
return NULL;
inf->inode = inode;
inode->i_mode = inf->mode;
if (sb->s_root) {
inode->i_uid = sb->s_root->d_inode->i_uid;
inode->i_gid = sb->s_root->d_inode->i_gid;
} else {
inode->i_uid = 0;
inode->i_gid = 0;
}
inode->i_blksize = PAGE_CACHE_SIZE;
inode->i_blocks = 0;
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
if (S_ISDIR(inf->mode)) {
inode->i_nlink = 2;
inode->i_op = &autofs4_dir_inode_operations;
inode->i_fop = &autofs4_dir_operations;
} else if (S_ISLNK(inf->mode)) {
inode->i_size = inf->size;
inode->i_op = &autofs4_symlink_inode_operations;
}
return inode;
}
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