Commit 2aa85937 authored by Alexander Viro's avatar Alexander Viro Committed by Linus Torvalds

[PATCH] devpts cleanup

	* devpts "upcalls" eliminated.
	* instead of playing games with revalidation we simply use
ramfs-style tree and kill dentries upon devpts_pty_kill().  That
allows to get rid of a lot of code in fs/devpts/*.c.
	* devpts_fs.h cleaned up.
	* devpts/root.c and devpts/devpts_i.h removed.
	* array of pointers to devpts inodes killed; with ramfs-style tree
it's not needed anymore.
	* devpts/inode.c cleaned up.
	* devpts_pty_new() used to get mk_kdev() only to convert it to
dev_t (hardly a surprise, since it's mknod() in disguise).  Now it gets
dev_t as an argument.
parent 2ffe5f2f
......@@ -25,8 +25,6 @@
#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/bitops.h>
#define BUILDING_PTY_C 1
#include <linux/devpts_fs.h>
struct pty_struct {
......
......@@ -1336,7 +1336,7 @@ static int tty_open(struct inode * inode, struct file * filp)
ptmx_found:
set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
minor -= driver->minor_start;
devpts_pty_new(driver->other->name_base + minor, mk_kdev(driver->other->major, minor + driver->other->minor_start));
devpts_pty_new(driver->other->name_base + minor, MKDEV(driver->other->major, minor + driver->other->minor_start));
tty_register_devfs(&pts_driver[major], DEVFS_FL_DEFAULT,
pts_driver[major].minor_start + minor);
noctty = 1;
......
......@@ -40,6 +40,7 @@ obj-$(CONFIG_QUOTACTL) += quota.o
obj-$(CONFIG_PROC_FS) += proc/
obj-y += partitions/
obj-y += driverfs/
obj-y += devpts/
# Do not add any filesystems before this line
obj-$(CONFIG_EXT3_FS) += ext3/ # Before ext2 so root fs can be ext3
......@@ -81,7 +82,6 @@ obj-$(CONFIG_AUTOFS_FS) += autofs/
obj-$(CONFIG_AUTOFS4_FS) += autofs4/
obj-$(CONFIG_ADFS_FS) += adfs/
obj-$(CONFIG_REISERFS_FS) += reiserfs/
obj-$(CONFIG_DEVPTS_FS) += devpts/
obj-$(CONFIG_SUN_OPENPROMFS) += openpromfs/
obj-$(CONFIG_JFS_FS) += jfs/
......
......@@ -4,6 +4,6 @@
obj-$(CONFIG_DEVPTS_FS) += devpts.o
devpts-objs := root.o inode.o
devpts-objs := inode.o
include $(TOPDIR)/Rules.make
/* -*- linux-c -*- --------------------------------------------------------- *
*
* linux/fs/devpts/devpts_i.h
*
* Copyright 1998 H. Peter Anvin -- 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/fs.h>
#include <linux/tty.h>
#include <linux/types.h>
#define BUILDING_DEVPTS 1
#include <linux/devpts_fs.h>
struct devpts_sb_info {
u32 magic;
int setuid;
int setgid;
uid_t uid;
gid_t gid;
umode_t mode;
unsigned int max_ptys;
struct inode **inodes;
};
#define DEVPTS_SUPER_MAGIC 0x1cd1
#define DEVPTS_SBI_MAGIC 0x01da1d02
extern inline struct devpts_sb_info *SBI(struct super_block *sb)
{
return (struct devpts_sb_info *)(sb->u.generic_sbp);
}
extern struct inode_operations devpts_root_inode_operations;
extern struct file_operations devpts_root_operations;
......@@ -11,135 +11,70 @@
* ------------------------------------------------------------------------- */
#include <linux/module.h>
#include <linux/string.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/kdev_t.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/slab.h>
#include <linux/stat.h>
#include <linux/tty.h>
#include <asm/bitops.h>
#include <asm/uaccess.h>
#include <linux/fs.h>
#include <linux/sched.h>
#include <linux/namei.h>
#include "devpts_i.h"
#define DEVPTS_SUPER_MAGIC 0x1cd1
static struct vfsmount *devpts_mnt;
static struct dentry *devpts_root;
static void devpts_put_super(struct super_block *sb)
{
struct devpts_sb_info *sbi = SBI(sb);
struct inode *inode;
int i;
static struct {
int setuid;
int setgid;
uid_t uid;
gid_t gid;
umode_t mode;
} config = {mode: 0600};
for ( i = 0 ; i < sbi->max_ptys ; i++ ) {
if ( (inode = sbi->inodes[i]) ) {
if ( atomic_read(&inode->i_count) != 1 )
printk("devpts_put_super: badness: entry %d count %d\n",
i, atomic_read(&inode->i_count));
inode->i_nlink--;
iput(inode);
}
}
kfree(sbi->inodes);
kfree(sbi);
}
static int devpts_remount (struct super_block * sb, int * flags, char * data);
static struct super_operations devpts_sops = {
put_super: devpts_put_super,
statfs: simple_statfs,
remount_fs: devpts_remount,
};
static int devpts_parse_options(char *options, struct devpts_sb_info *sbi)
static int devpts_remount(struct super_block *sb, int *flags, char *data)
{
int setuid = 0;
int setgid = 0;
uid_t uid = 0;
gid_t gid = 0;
umode_t mode = 0600;
char *this_char, *value;
char *this_char;
this_char = NULL;
while ((this_char = strsep(&options, ",")) != NULL) {
while ((this_char = strsep(&data, ",")) != NULL) {
int n;
char dummy;
if (!*this_char)
continue;
if ((value = strchr(this_char,'=')) != NULL)
*value++ = 0;
if (!strcmp(this_char,"uid")) {
if (!value || !*value)
return 1;
uid = simple_strtoul(value,&value,0);
if (*value)
return 1;
if (sscanf(this_char, "uid=%i%c", &n, &dummy) == 1) {
setuid = 1;
}
else if (!strcmp(this_char,"gid")) {
if (!value || !*value)
return 1;
gid = simple_strtoul(value,&value,0);
if (*value)
return 1;
uid = n;
} else if (sscanf(this_char, "gid=%i%c", &n, &dummy) == 1) {
setgid = 1;
gid = n;
} else if (sscanf(this_char, "mode=%o%c", &n, &dummy) == 1)
mode = n & ~S_IFMT;
else {
printk("devpts: called with bogus options\n");
return -EINVAL;
}
else if (!strcmp(this_char,"mode")) {
if (!value || !*value)
return 1;
mode = simple_strtoul(value,&value,8);
if (*value)
return 1;
}
else
return 1;
}
sbi->setuid = setuid;
sbi->setgid = setgid;
sbi->uid = uid;
sbi->gid = gid;
sbi->mode = mode & ~S_IFMT;
config.setuid = setuid;
config.setgid = setgid;
config.uid = uid;
config.gid = gid;
config.mode = mode;
return 0;
}
static int devpts_remount(struct super_block * sb, int * flags, char * data)
{
struct devpts_sb_info *sbi = sb->u.generic_sbp;
int res = devpts_parse_options(data,sbi);
if (res) {
printk("devpts: called with bogus options\n");
return -EINVAL;
}
return 0;
}
static struct super_operations devpts_sops = {
statfs: simple_statfs,
remount_fs: devpts_remount,
};
static int devpts_fill_super(struct super_block *s, void *data, int silent)
{
int error = -ENOMEM;
struct inode * inode;
struct devpts_sb_info *sbi;
sbi = kmalloc(sizeof(*sbi), GFP_KERNEL);
if ( !sbi )
goto fail;
memset(sbi, 0, sizeof(*sbi));
sbi->magic = DEVPTS_SBI_MAGIC;
sbi->max_ptys = unix98_max_ptys;
sbi->inodes = kmalloc(sizeof(struct inode *) * sbi->max_ptys, GFP_KERNEL);
if ( !sbi->inodes )
goto fail_free;
memset(sbi->inodes, 0, sizeof(struct inode *) * sbi->max_ptys);
if ( devpts_parse_options(data,sbi) && !silent) {
error = -EINVAL;
printk("devpts: called with bogus options\n");
goto fail_free;
}
s->u.generic_sbp = (void *) sbi;
s->s_blocksize = 1024;
s->s_blocksize_bits = 10;
s->s_magic = DEVPTS_SUPER_MAGIC;
......@@ -147,27 +82,25 @@ static int devpts_fill_super(struct super_block *s, void *data, int silent)
inode = new_inode(s);
if (!inode)
goto fail_free;
goto fail;
inode->i_ino = 1;
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
inode->i_blocks = 0;
inode->i_blksize = 1024;
inode->i_uid = inode->i_gid = 0;
inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO | S_IWUSR;
inode->i_op = &devpts_root_inode_operations;
inode->i_fop = &devpts_root_operations;
inode->i_op = &simple_dir_inode_operations;
inode->i_fop = &simple_dir_operations;
inode->i_nlink = 2;
s->s_root = d_alloc_root(inode);
devpts_root = s->s_root = d_alloc_root(inode);
if (s->s_root)
return 0;
printk("devpts: get root dentry failed\n");
iput(inode);
fail_free:
kfree(sbi);
fail:
return error;
return -ENOMEM;
}
static struct super_block *devpts_get_sb(struct file_system_type *fs_type,
......@@ -183,44 +116,52 @@ static struct file_system_type devpts_fs_type = {
kill_sb: kill_anon_super,
};
void devpts_pty_new(int number, kdev_t device)
/*
* The normal naming convention is simply /dev/pts/<number>; this conforms
* to the System V naming convention
*/
static struct dentry *get_node(int num)
{
struct super_block *sb = devpts_mnt->mnt_sb;
struct devpts_sb_info *sbi = SBI(sb);
struct inode *inode;
if ( sbi->inodes[number] )
return; /* Already registered, this does happen */
inode = new_inode(sb);
char s[10];
struct dentry *root = devpts_root;
down(&root->d_inode->i_sem);
return lookup_one_len(s, root, sprintf(s, "%d", num));
}
void devpts_pty_new(int number, dev_t device)
{
struct dentry *dentry;
struct inode *inode = new_inode(devpts_mnt->mnt_sb);
if (!inode)
return;
inode->i_ino = number+2;
inode->i_blocks = 0;
inode->i_blksize = 1024;
inode->i_uid = sbi->setuid ? sbi->uid : current->fsuid;
inode->i_gid = sbi->setgid ? sbi->gid : current->fsgid;
inode->i_uid = config.setuid ? config.uid : current->fsuid;
inode->i_gid = config.setgid ? config.gid : current->fsgid;
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
init_special_inode(inode, S_IFCHR|sbi->mode, kdev_t_to_nr(device));
init_special_inode(inode, S_IFCHR|config.mode, device);
if ( sbi->inodes[number] ) {
iput(inode);
return;
}
sbi->inodes[number] = inode;
dentry = get_node(number);
if (!IS_ERR(dentry) && !dentry->d_inode)
d_instantiate(dentry, inode);
up(&devpts_root->d_inode->i_sem);
}
void devpts_pty_kill(int number)
{
struct super_block *sb = devpts_mnt->mnt_sb;
struct devpts_sb_info *sbi = SBI(sb);
struct inode *inode = sbi->inodes[number];
struct dentry *dentry = get_node(number);
if ( inode ) {
sbi->inodes[number] = NULL;
inode->i_nlink--;
iput(inode);
if (!IS_ERR(dentry)) {
struct inode *inode = dentry->d_inode;
if (inode) {
inode->i_nlink--;
d_delete(dentry);
dput(dentry);
}
dput(dentry);
}
up(&devpts_root->d_inode->i_sem);
}
static int __init init_devpts_fs(void)
......@@ -231,22 +172,12 @@ static int __init init_devpts_fs(void)
err = PTR_ERR(devpts_mnt);
if (!IS_ERR(devpts_mnt))
err = 0;
#ifdef MODULE
if ( !err ) {
devpts_upcall_new = devpts_pty_new;
devpts_upcall_kill = devpts_pty_kill;
}
#endif
}
return err;
}
static void __exit exit_devpts_fs(void)
{
#ifdef MODULE
devpts_upcall_new = NULL;
devpts_upcall_kill = NULL;
#endif
unregister_filesystem(&devpts_fs_type);
kern_umount(devpts_mnt);
}
......@@ -254,4 +185,3 @@ static void __exit exit_devpts_fs(void)
module_init(init_devpts_fs)
module_exit(exit_devpts_fs)
MODULE_LICENSE("GPL");
/* -*- linux-c -*- --------------------------------------------------------- *
*
* linux/fs/devpts/root.c
*
* Copyright 1998 H. Peter Anvin -- 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/string.h>
#include <linux/smp_lock.h>
#include "devpts_i.h"
static int devpts_root_readdir(struct file *,void *,filldir_t);
static struct dentry *devpts_root_lookup(struct inode *,struct dentry *);
static int devpts_revalidate(struct dentry *, int);
struct file_operations devpts_root_operations = {
read: generic_read_dir,
readdir: devpts_root_readdir,
};
struct inode_operations devpts_root_inode_operations = {
lookup: devpts_root_lookup,
};
static struct dentry_operations devpts_dentry_operations = {
d_revalidate: devpts_revalidate,
};
/*
* The normal naming convention is simply /dev/pts/<number>; this conforms
* to the System V naming convention
*/
#define genptsname(buf,num) sprintf(buf, "%d", num)
static int devpts_root_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
struct inode * inode = filp->f_dentry->d_inode;
struct devpts_sb_info * sbi = SBI(filp->f_dentry->d_inode->i_sb);
off_t nr;
char numbuf[16];
lock_kernel();
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 ( nr - 2 < sbi->max_ptys ) {
int ptynr = nr - 2;
if ( sbi->inodes[ptynr] ) {
genptsname(numbuf, ptynr);
if ( filldir(dirent, numbuf, strlen(numbuf), nr, nr, DT_CHR) < 0 )
goto out;
}
filp->f_pos = ++nr;
}
break;
}
out:
unlock_kernel();
return 0;
}
/*
* Revalidate is called on every cache lookup. We use it to check that
* the pty really does still exist. Never revalidate negative dentries;
* for simplicity (fix later?)
*/
static int devpts_revalidate(struct dentry * dentry, int flags)
{
struct devpts_sb_info *sbi;
if ( !dentry->d_inode )
return 0;
sbi = SBI(dentry->d_inode->i_sb);
return ( sbi->inodes[dentry->d_inode->i_ino - 2] == dentry->d_inode );
}
static struct dentry *devpts_root_lookup(struct inode * dir, struct dentry * dentry)
{
struct devpts_sb_info *sbi = SBI(dir->i_sb);
unsigned int entry;
int i;
const char *p;
dentry->d_op = &devpts_dentry_operations;
if ( dentry->d_name.len == 1 && dentry->d_name.name[0] == '0' ) {
entry = 0;
} else if ( dentry->d_name.len < 1 ) {
return NULL;
} else {
p = dentry->d_name.name;
if ( *p < '1' || *p > '9' )
return NULL;
entry = *p++ - '0';
for ( i = dentry->d_name.len-1 ; i ; i-- ) {
unsigned int nentry = *p++ - '0';
if ( nentry > 9 )
return NULL;
if ( entry >= ~0U/10 )
return NULL;
entry = nentry + entry * 10;
}
}
if ( entry >= sbi->max_ptys )
return NULL;
lock_kernel();
if ( sbi->inodes[entry] )
atomic_inc(&sbi->inodes[entry]->i_count);
d_add(dentry, sbi->inodes[entry]);
unlock_kernel();
return NULL;
}
......@@ -10,64 +10,23 @@
*
* ------------------------------------------------------------------------- */
/*
* Prototypes for the pty driver <-> devpts filesystem interface. Most
* of this is really just a hack so we can exclude it or build it as a
* module, and probably should go away eventually.
*/
#ifndef _LINUX_DEVPTS_FS_H
#define _LINUX_DEVPTS_FS_H 1
#include <linux/config.h>
#include <linux/kdev_t.h>
#include <linux/tty.h>
#ifdef CONFIG_DEVPTS_FS
void devpts_pty_new(int, kdev_t);
void devpts_pty_kill(int);
#define unix98_max_ptys NR_PTYS * UNIX98_NR_MAJORS;
#elif defined(CONFIG_DEVPTS_FS_MODULE)
void devpts_pty_new(int, dev_t); /* mknod in devpts */
void devpts_pty_kill(int); /* unlink */
#ifdef BUILDING_PTY_C
void (*devpts_upcall_new)(int,kdev_t) = NULL;
void (*devpts_upcall_kill)(int) = NULL;
unsigned int unix98_max_ptys = NR_PTYS * UNIX98_NR_MAJORS;
EXPORT_SYMBOL(devpts_upcall_new);
EXPORT_SYMBOL(devpts_upcall_kill);
EXPORT_SYMBOL(unix98_max_ptys);
#else
extern void (*devpts_upcall_new)(int,kdev_t);
extern void (*devpts_upcall_kill)(int);
extern unsigned int unix98_max_ptys;
#endif
#ifndef BUILDING_DEVPTS
static inline void
devpts_pty_new(int line, kdev_t device)
static inline void devpts_pty_new(int line, dev_t device)
{
if ( devpts_upcall_new )
return devpts_upcall_new(line,device);
}
static inline void
devpts_pty_kill(int line)
static inline void devpts_pty_kill(int line)
{
if ( devpts_upcall_kill )
return devpts_upcall_kill(line);
}
#endif
#else /* No /dev/pts filesystem at all */
static inline void
devpts_pty_new(int line, kdev_t device) { }
static inline void
devpts_pty_kill(int line) { }
#endif
......
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