mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-23 20:24:12 +08:00
1da177e4c3
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!
565 lines
15 KiB
C
565 lines
15 KiB
C
/* -*- linux-c -*- --------------------------------------------------------- *
|
|
*
|
|
* linux/fs/autofs/root.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/errno.h>
|
|
#include <linux/stat.h>
|
|
#include <linux/param.h>
|
|
#include <linux/time.h>
|
|
#include <linux/smp_lock.h>
|
|
#include "autofs_i.h"
|
|
|
|
static int autofs_root_readdir(struct file *,void *,filldir_t);
|
|
static struct dentry *autofs_root_lookup(struct inode *,struct dentry *, struct nameidata *);
|
|
static int autofs_root_symlink(struct inode *,struct dentry *,const char *);
|
|
static int autofs_root_unlink(struct inode *,struct dentry *);
|
|
static int autofs_root_rmdir(struct inode *,struct dentry *);
|
|
static int autofs_root_mkdir(struct inode *,struct dentry *,int);
|
|
static int autofs_root_ioctl(struct inode *, struct file *,unsigned int,unsigned long);
|
|
|
|
struct file_operations autofs_root_operations = {
|
|
.read = generic_read_dir,
|
|
.readdir = autofs_root_readdir,
|
|
.ioctl = autofs_root_ioctl,
|
|
};
|
|
|
|
struct inode_operations autofs_root_inode_operations = {
|
|
.lookup = autofs_root_lookup,
|
|
.unlink = autofs_root_unlink,
|
|
.symlink = autofs_root_symlink,
|
|
.mkdir = autofs_root_mkdir,
|
|
.rmdir = autofs_root_rmdir,
|
|
};
|
|
|
|
static int autofs_root_readdir(struct file *filp, void *dirent, filldir_t filldir)
|
|
{
|
|
struct autofs_dir_ent *ent = NULL;
|
|
struct autofs_dirhash *dirhash;
|
|
struct autofs_sb_info *sbi;
|
|
struct inode * inode = filp->f_dentry->d_inode;
|
|
off_t onr, nr;
|
|
|
|
lock_kernel();
|
|
|
|
sbi = autofs_sbi(inode->i_sb);
|
|
dirhash = &sbi->dirhash;
|
|
nr = filp->f_pos;
|
|
|
|
switch(nr)
|
|
{
|
|
case 0:
|
|
if (filldir(dirent, ".", 1, nr, inode->i_ino, DT_DIR) < 0)
|
|
goto out;
|
|
filp->f_pos = ++nr;
|
|
/* fall through */
|
|
case 1:
|
|
if (filldir(dirent, "..", 2, nr, inode->i_ino, DT_DIR) < 0)
|
|
goto out;
|
|
filp->f_pos = ++nr;
|
|
/* fall through */
|
|
default:
|
|
while ( onr = nr, ent = autofs_hash_enum(dirhash,&nr,ent) ) {
|
|
if ( !ent->dentry || d_mountpoint(ent->dentry) ) {
|
|
if (filldir(dirent,ent->name,ent->len,onr,ent->ino,DT_UNKNOWN) < 0)
|
|
goto out;
|
|
filp->f_pos = nr;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
|
|
out:
|
|
unlock_kernel();
|
|
return 0;
|
|
}
|
|
|
|
static int try_to_fill_dentry(struct dentry *dentry, struct super_block *sb, struct autofs_sb_info *sbi)
|
|
{
|
|
struct inode * inode;
|
|
struct autofs_dir_ent *ent;
|
|
int status = 0;
|
|
|
|
if ( !(ent = autofs_hash_lookup(&sbi->dirhash, &dentry->d_name)) ) {
|
|
do {
|
|
if ( status && dentry->d_inode ) {
|
|
if ( status != -ENOENT )
|
|
printk("autofs warning: lookup failure on positive dentry, status = %d, name = %s\n", status, dentry->d_name.name);
|
|
return 0; /* Try to get the kernel to invalidate this dentry */
|
|
}
|
|
|
|
/* Turn this into a real negative dentry? */
|
|
if (status == -ENOENT) {
|
|
dentry->d_time = jiffies + AUTOFS_NEGATIVE_TIMEOUT;
|
|
dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
|
|
return 1;
|
|
} else if (status) {
|
|
/* Return a negative dentry, but leave it "pending" */
|
|
return 1;
|
|
}
|
|
status = autofs_wait(sbi, &dentry->d_name);
|
|
} while (!(ent = autofs_hash_lookup(&sbi->dirhash, &dentry->d_name)) );
|
|
}
|
|
|
|
/* Abuse this field as a pointer to the directory entry, used to
|
|
find the expire list pointers */
|
|
dentry->d_time = (unsigned long) ent;
|
|
|
|
if (!dentry->d_inode) {
|
|
inode = iget(sb, ent->ino);
|
|
if (!inode) {
|
|
/* Failed, but leave pending for next time */
|
|
return 1;
|
|
}
|
|
dentry->d_inode = inode;
|
|
}
|
|
|
|
/* If this is a directory that isn't a mount point, bitch at the
|
|
daemon and fix it in user space */
|
|
if ( S_ISDIR(dentry->d_inode->i_mode) && !d_mountpoint(dentry) ) {
|
|
return !autofs_wait(sbi, &dentry->d_name);
|
|
}
|
|
|
|
/* We don't update the usages for the autofs daemon itself, this
|
|
is necessary for recursive autofs mounts */
|
|
if ( !autofs_oz_mode(sbi) ) {
|
|
autofs_update_usage(&sbi->dirhash,ent);
|
|
}
|
|
|
|
dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
|
|
return 1;
|
|
}
|
|
|
|
|
|
/*
|
|
* Revalidate is called on every cache lookup. Some of those
|
|
* cache lookups may actually happen while the dentry is not
|
|
* yet completely filled in, and revalidate has to delay such
|
|
* lookups..
|
|
*/
|
|
static int autofs_revalidate(struct dentry * dentry, struct nameidata *nd)
|
|
{
|
|
struct inode * dir;
|
|
struct autofs_sb_info *sbi;
|
|
struct autofs_dir_ent *ent;
|
|
int res;
|
|
|
|
lock_kernel();
|
|
dir = dentry->d_parent->d_inode;
|
|
sbi = autofs_sbi(dir->i_sb);
|
|
|
|
/* Pending dentry */
|
|
if ( dentry->d_flags & DCACHE_AUTOFS_PENDING ) {
|
|
if (autofs_oz_mode(sbi))
|
|
res = 1;
|
|
else
|
|
res = try_to_fill_dentry(dentry, dir->i_sb, sbi);
|
|
unlock_kernel();
|
|
return res;
|
|
}
|
|
|
|
/* Negative dentry.. invalidate if "old" */
|
|
if (!dentry->d_inode) {
|
|
unlock_kernel();
|
|
return (dentry->d_time - jiffies <= AUTOFS_NEGATIVE_TIMEOUT);
|
|
}
|
|
|
|
/* Check for a non-mountpoint directory */
|
|
if ( S_ISDIR(dentry->d_inode->i_mode) && !d_mountpoint(dentry) ) {
|
|
if (autofs_oz_mode(sbi))
|
|
res = 1;
|
|
else
|
|
res = try_to_fill_dentry(dentry, dir->i_sb, sbi);
|
|
unlock_kernel();
|
|
return res;
|
|
}
|
|
|
|
/* Update the usage list */
|
|
if ( !autofs_oz_mode(sbi) ) {
|
|
ent = (struct autofs_dir_ent *) dentry->d_time;
|
|
if ( ent )
|
|
autofs_update_usage(&sbi->dirhash,ent);
|
|
}
|
|
unlock_kernel();
|
|
return 1;
|
|
}
|
|
|
|
static struct dentry_operations autofs_dentry_operations = {
|
|
.d_revalidate = autofs_revalidate,
|
|
};
|
|
|
|
static struct dentry *autofs_root_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
|
|
{
|
|
struct autofs_sb_info *sbi;
|
|
int oz_mode;
|
|
|
|
DPRINTK(("autofs_root_lookup: name = "));
|
|
lock_kernel();
|
|
autofs_say(dentry->d_name.name,dentry->d_name.len);
|
|
|
|
if (dentry->d_name.len > NAME_MAX) {
|
|
unlock_kernel();
|
|
return ERR_PTR(-ENAMETOOLONG);/* File name too long to exist */
|
|
}
|
|
|
|
sbi = autofs_sbi(dir->i_sb);
|
|
|
|
oz_mode = autofs_oz_mode(sbi);
|
|
DPRINTK(("autofs_lookup: pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d\n",
|
|
current->pid, process_group(current), sbi->catatonic, oz_mode));
|
|
|
|
/*
|
|
* Mark the dentry incomplete, but add it. This is needed so
|
|
* that the VFS layer knows about the dentry, and we can count
|
|
* on catching any lookups through the revalidate.
|
|
*
|
|
* Let all the hard work be done by the revalidate function that
|
|
* needs to be able to do this anyway..
|
|
*
|
|
* We need to do this before we release the directory semaphore.
|
|
*/
|
|
dentry->d_op = &autofs_dentry_operations;
|
|
dentry->d_flags |= DCACHE_AUTOFS_PENDING;
|
|
d_add(dentry, NULL);
|
|
|
|
up(&dir->i_sem);
|
|
autofs_revalidate(dentry, nd);
|
|
down(&dir->i_sem);
|
|
|
|
/*
|
|
* If we are still pending, check if we had to handle
|
|
* a signal. If so we can force a restart..
|
|
*/
|
|
if (dentry->d_flags & DCACHE_AUTOFS_PENDING) {
|
|
/* See if we were interrupted */
|
|
if (signal_pending(current)) {
|
|
sigset_t *sigset = ¤t->pending.signal;
|
|
if (sigismember (sigset, SIGKILL) ||
|
|
sigismember (sigset, SIGQUIT) ||
|
|
sigismember (sigset, SIGINT)) {
|
|
unlock_kernel();
|
|
return ERR_PTR(-ERESTARTNOINTR);
|
|
}
|
|
}
|
|
}
|
|
unlock_kernel();
|
|
|
|
/*
|
|
* If this dentry is unhashed, then we shouldn't honour this
|
|
* lookup even if the dentry is positive. Returning ENOENT here
|
|
* doesn't do the right thing for all system calls, but it should
|
|
* be OK for the operations we permit from an autofs.
|
|
*/
|
|
if ( dentry->d_inode && d_unhashed(dentry) )
|
|
return ERR_PTR(-ENOENT);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static int autofs_root_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
|
|
{
|
|
struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
|
|
struct autofs_dirhash *dh = &sbi->dirhash;
|
|
struct autofs_dir_ent *ent;
|
|
unsigned int n;
|
|
int slsize;
|
|
struct autofs_symlink *sl;
|
|
|
|
DPRINTK(("autofs_root_symlink: %s <- ", symname));
|
|
autofs_say(dentry->d_name.name,dentry->d_name.len);
|
|
|
|
lock_kernel();
|
|
if ( !autofs_oz_mode(sbi) ) {
|
|
unlock_kernel();
|
|
return -EACCES;
|
|
}
|
|
|
|
if ( autofs_hash_lookup(dh, &dentry->d_name) ) {
|
|
unlock_kernel();
|
|
return -EEXIST;
|
|
}
|
|
|
|
n = find_first_zero_bit(sbi->symlink_bitmap,AUTOFS_MAX_SYMLINKS);
|
|
if ( n >= AUTOFS_MAX_SYMLINKS ) {
|
|
unlock_kernel();
|
|
return -ENOSPC;
|
|
}
|
|
|
|
set_bit(n,sbi->symlink_bitmap);
|
|
sl = &sbi->symlink[n];
|
|
sl->len = strlen(symname);
|
|
sl->data = kmalloc(slsize = sl->len+1, GFP_KERNEL);
|
|
if ( !sl->data ) {
|
|
clear_bit(n,sbi->symlink_bitmap);
|
|
unlock_kernel();
|
|
return -ENOSPC;
|
|
}
|
|
|
|
ent = kmalloc(sizeof(struct autofs_dir_ent), GFP_KERNEL);
|
|
if ( !ent ) {
|
|
kfree(sl->data);
|
|
clear_bit(n,sbi->symlink_bitmap);
|
|
unlock_kernel();
|
|
return -ENOSPC;
|
|
}
|
|
|
|
ent->name = kmalloc(dentry->d_name.len+1, GFP_KERNEL);
|
|
if ( !ent->name ) {
|
|
kfree(sl->data);
|
|
kfree(ent);
|
|
clear_bit(n,sbi->symlink_bitmap);
|
|
unlock_kernel();
|
|
return -ENOSPC;
|
|
}
|
|
|
|
memcpy(sl->data,symname,slsize);
|
|
sl->mtime = get_seconds();
|
|
|
|
ent->ino = AUTOFS_FIRST_SYMLINK + n;
|
|
ent->hash = dentry->d_name.hash;
|
|
memcpy(ent->name, dentry->d_name.name, 1+(ent->len = dentry->d_name.len));
|
|
ent->dentry = NULL; /* We don't keep the dentry for symlinks */
|
|
|
|
autofs_hash_insert(dh,ent);
|
|
d_instantiate(dentry, iget(dir->i_sb,ent->ino));
|
|
unlock_kernel();
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* NOTE!
|
|
*
|
|
* Normal filesystems would do a "d_delete()" to tell the VFS dcache
|
|
* that the file no longer exists. However, doing that means that the
|
|
* VFS layer can turn the dentry into a negative dentry, which we
|
|
* obviously do not want (we're dropping the entry not because it
|
|
* doesn't exist, but because it has timed out).
|
|
*
|
|
* Also see autofs_root_rmdir()..
|
|
*/
|
|
static int autofs_root_unlink(struct inode *dir, struct dentry *dentry)
|
|
{
|
|
struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
|
|
struct autofs_dirhash *dh = &sbi->dirhash;
|
|
struct autofs_dir_ent *ent;
|
|
unsigned int n;
|
|
|
|
/* This allows root to remove symlinks */
|
|
lock_kernel();
|
|
if ( !autofs_oz_mode(sbi) && !capable(CAP_SYS_ADMIN) ) {
|
|
unlock_kernel();
|
|
return -EACCES;
|
|
}
|
|
|
|
ent = autofs_hash_lookup(dh, &dentry->d_name);
|
|
if ( !ent ) {
|
|
unlock_kernel();
|
|
return -ENOENT;
|
|
}
|
|
|
|
n = ent->ino - AUTOFS_FIRST_SYMLINK;
|
|
if ( n >= AUTOFS_MAX_SYMLINKS ) {
|
|
unlock_kernel();
|
|
return -EISDIR; /* It's a directory, dummy */
|
|
}
|
|
if ( !test_bit(n,sbi->symlink_bitmap) ) {
|
|
unlock_kernel();
|
|
return -EINVAL; /* Nonexistent symlink? Shouldn't happen */
|
|
}
|
|
|
|
dentry->d_time = (unsigned long)(struct autofs_dirhash *)NULL;
|
|
autofs_hash_delete(ent);
|
|
clear_bit(n,sbi->symlink_bitmap);
|
|
kfree(sbi->symlink[n].data);
|
|
d_drop(dentry);
|
|
|
|
unlock_kernel();
|
|
return 0;
|
|
}
|
|
|
|
static int autofs_root_rmdir(struct inode *dir, struct dentry *dentry)
|
|
{
|
|
struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
|
|
struct autofs_dirhash *dh = &sbi->dirhash;
|
|
struct autofs_dir_ent *ent;
|
|
|
|
lock_kernel();
|
|
if ( !autofs_oz_mode(sbi) ) {
|
|
unlock_kernel();
|
|
return -EACCES;
|
|
}
|
|
|
|
ent = autofs_hash_lookup(dh, &dentry->d_name);
|
|
if ( !ent ) {
|
|
unlock_kernel();
|
|
return -ENOENT;
|
|
}
|
|
|
|
if ( (unsigned int)ent->ino < AUTOFS_FIRST_DIR_INO ) {
|
|
unlock_kernel();
|
|
return -ENOTDIR; /* Not a directory */
|
|
}
|
|
|
|
if ( ent->dentry != dentry ) {
|
|
printk("autofs_rmdir: odentry != dentry for entry %s\n", dentry->d_name.name);
|
|
}
|
|
|
|
dentry->d_time = (unsigned long)(struct autofs_dir_ent *)NULL;
|
|
autofs_hash_delete(ent);
|
|
dir->i_nlink--;
|
|
d_drop(dentry);
|
|
unlock_kernel();
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int autofs_root_mkdir(struct inode *dir, struct dentry *dentry, int mode)
|
|
{
|
|
struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
|
|
struct autofs_dirhash *dh = &sbi->dirhash;
|
|
struct autofs_dir_ent *ent;
|
|
ino_t ino;
|
|
|
|
lock_kernel();
|
|
if ( !autofs_oz_mode(sbi) ) {
|
|
unlock_kernel();
|
|
return -EACCES;
|
|
}
|
|
|
|
ent = autofs_hash_lookup(dh, &dentry->d_name);
|
|
if ( ent ) {
|
|
unlock_kernel();
|
|
return -EEXIST;
|
|
}
|
|
|
|
if ( sbi->next_dir_ino < AUTOFS_FIRST_DIR_INO ) {
|
|
printk("autofs: Out of inode numbers -- what the heck did you do??\n");
|
|
unlock_kernel();
|
|
return -ENOSPC;
|
|
}
|
|
ino = sbi->next_dir_ino++;
|
|
|
|
ent = kmalloc(sizeof(struct autofs_dir_ent), GFP_KERNEL);
|
|
if ( !ent ) {
|
|
unlock_kernel();
|
|
return -ENOSPC;
|
|
}
|
|
|
|
ent->name = kmalloc(dentry->d_name.len+1, GFP_KERNEL);
|
|
if ( !ent->name ) {
|
|
kfree(ent);
|
|
unlock_kernel();
|
|
return -ENOSPC;
|
|
}
|
|
|
|
ent->hash = dentry->d_name.hash;
|
|
memcpy(ent->name, dentry->d_name.name, 1+(ent->len = dentry->d_name.len));
|
|
ent->ino = ino;
|
|
ent->dentry = dentry;
|
|
autofs_hash_insert(dh,ent);
|
|
|
|
dir->i_nlink++;
|
|
d_instantiate(dentry, iget(dir->i_sb,ino));
|
|
unlock_kernel();
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Get/set timeout ioctl() operation */
|
|
static inline int autofs_get_set_timeout(struct autofs_sb_info *sbi,
|
|
unsigned long __user *p)
|
|
{
|
|
unsigned long ntimeout;
|
|
|
|
if (get_user(ntimeout, p) ||
|
|
put_user(sbi->exp_timeout / HZ, p))
|
|
return -EFAULT;
|
|
|
|
if ( ntimeout > ULONG_MAX/HZ )
|
|
sbi->exp_timeout = 0;
|
|
else
|
|
sbi->exp_timeout = ntimeout * HZ;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Return protocol version */
|
|
static inline int autofs_get_protover(int __user *p)
|
|
{
|
|
return put_user(AUTOFS_PROTO_VERSION, p);
|
|
}
|
|
|
|
/* Perform an expiry operation */
|
|
static inline int autofs_expire_run(struct super_block *sb,
|
|
struct autofs_sb_info *sbi,
|
|
struct vfsmount *mnt,
|
|
struct autofs_packet_expire __user *pkt_p)
|
|
{
|
|
struct autofs_dir_ent *ent;
|
|
struct autofs_packet_expire pkt;
|
|
|
|
memset(&pkt,0,sizeof pkt);
|
|
|
|
pkt.hdr.proto_version = AUTOFS_PROTO_VERSION;
|
|
pkt.hdr.type = autofs_ptype_expire;
|
|
|
|
if ( !sbi->exp_timeout ||
|
|
!(ent = autofs_expire(sb,sbi,mnt)) )
|
|
return -EAGAIN;
|
|
|
|
pkt.len = ent->len;
|
|
memcpy(pkt.name, ent->name, pkt.len);
|
|
pkt.name[pkt.len] = '\0';
|
|
|
|
if ( copy_to_user(pkt_p, &pkt, sizeof(struct autofs_packet_expire)) )
|
|
return -EFAULT;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* ioctl()'s on the root directory is the chief method for the daemon to
|
|
* generate kernel reactions
|
|
*/
|
|
static int autofs_root_ioctl(struct inode *inode, struct file *filp,
|
|
unsigned int cmd, unsigned long arg)
|
|
{
|
|
struct autofs_sb_info *sbi = autofs_sbi(inode->i_sb);
|
|
void __user *argp = (void __user *)arg;
|
|
|
|
DPRINTK(("autofs_ioctl: cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u\n",cmd,arg,sbi,process_group(current)));
|
|
|
|
if ( _IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) ||
|
|
_IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT )
|
|
return -ENOTTY;
|
|
|
|
if ( !autofs_oz_mode(sbi) && !capable(CAP_SYS_ADMIN) )
|
|
return -EPERM;
|
|
|
|
switch(cmd) {
|
|
case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */
|
|
return autofs_wait_release(sbi,(autofs_wqt_t)arg,0);
|
|
case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */
|
|
return autofs_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT);
|
|
case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */
|
|
autofs_catatonic_mode(sbi);
|
|
return 0;
|
|
case AUTOFS_IOC_PROTOVER: /* Get protocol version */
|
|
return autofs_get_protover(argp);
|
|
case AUTOFS_IOC_SETTIMEOUT:
|
|
return autofs_get_set_timeout(sbi, argp);
|
|
case AUTOFS_IOC_EXPIRE:
|
|
return autofs_expire_run(inode->i_sb, sbi, filp->f_vfsmnt,
|
|
argp);
|
|
default:
|
|
return -ENOSYS;
|
|
}
|
|
}
|