Viewing file:  super.c (15.94 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
/*
* presto's super.c
*
* Copyright (C) 1998 Peter J. Braam
* Copyright (C) 2000 Stelias Computing, Inc.
* Copyright (C) 2000 Red Hat, Inc.
*
*
*/
#include <stdarg.h>
#include <asm/bitops.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/ext2_fs.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/sched.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/locks.h>
#include <linux/blkdev.h>
#include <linux/init.h>
#define __NO_VERSION__
#include <linux/module.h>
#include <linux/intermezzo_fs.h>
#include <linux/intermezzo_upcall.h>
#include <linux/intermezzo_psdev.h>
#ifdef PRESTO_DEBUG
long presto_vmemory = 0;
long presto_kmemory = 0;
#endif
extern struct presto_cache *presto_init_cache(void);
extern inline void presto_cache_add(struct presto_cache *cache, kdev_t dev);
extern inline void presto_init_cache_hash(void);
int presto_remount(struct super_block *, int *, char *);
extern ssize_t presto_file_write(struct file *file, const char *buf,
size_t size, loff_t *off);
/*
* Reading the super block.
*
*
*
*/
/* returns an allocated string, copied out from data if opt is found */
static char *read_opt(const char *opt, char *data)
{
char *value;
char *retval;
CDEBUG(D_SUPER, "option: %s, data %s\n", opt, data);
if ( strncmp(opt, data, strlen(opt)) )
return NULL;
if ( (value = strchr(data, '=')) == NULL )
return NULL;
value++;
PRESTO_ALLOC(retval, char *, strlen(value) + 1);
if ( !retval ) {
printk("InterMezzo: Out of memory!\n");
return NULL;
}
strcpy(retval, value);
CDEBUG(D_SUPER, "Assigned option: %s, value %s\n", opt, retval);
return retval;
}
static void store_opt(char **dst, char *opt, char *defval)
{
if (dst) {
if (*dst) {
PRESTO_FREE(*dst, strlen(*dst) + 1);
}
*dst = opt;
} else {
printk("presto: store_opt, error dst == NULL\n");
}
if (!opt && defval) {
char *def_alloced;
PRESTO_ALLOC(def_alloced, char *, strlen(defval)+1);
strcpy(def_alloced, defval);
*dst = def_alloced;
}
}
/* Find the options for InterMezzo in "options", saving them into the
* passed pointers. If the pointer is null, the option is discarded.
* Copy out all non-InterMezzo options into cache_data (to be passed
* to the read_super operation of the cache). The return value will
* be a pointer to the end of the cache_data.
*/
static char *presto_options(char *options, char *cache_data,
char **cache_type, char **fileset,
char **prestodev, char **mtpt)
{
char *this_char;
char *cache_data_end = cache_data;
if (!options || !cache_data)
return cache_data_end;
/* set the defaults */
store_opt(cache_type, NULL, "ext3");
store_opt(prestodev, NULL, PRESTO_PSDEV_NAME "0");
CDEBUG(D_SUPER, "parsing options\n");
for (this_char = strtok (options, ",");
this_char != NULL;
this_char = strtok (NULL, ",")) {
char *opt;
CDEBUG(D_SUPER, "this_char %s\n", this_char);
if ( (opt = read_opt("fileset", this_char)) ) {
store_opt(fileset, opt, NULL);
continue;
}
if ( (opt = read_opt("cache_type", this_char)) ) {
store_opt(cache_type, opt, "ext3");
continue;
}
if ( (opt = read_opt("mtpt", this_char)) ) {
store_opt(mtpt, opt, NULL);
continue;
}
if ( (opt = read_opt("prestodev", this_char)) ) {
store_opt(prestodev, opt, PRESTO_PSDEV_NAME);
continue;
}
cache_data_end += sprintf(cache_data_end, "%s%s",
cache_data_end != cache_data ? ",":"",
this_char);
}
return cache_data_end;
}
/*
map a /dev/intermezzoX path to a minor:
used to validate mount options passed to InterMezzo
*/
static int presto_get_minor(char *dev_path, int *minor)
{
struct nameidata nd;
struct dentry *dentry;
kdev_t devno = 0;
int error;
ENTRY;
/* Special case for root filesystem - use minor 0 always. */
if ( current->pid == 1 ) {
*minor = 0;
return 0;
}
error = presto_walk(dev_path, &nd);
if (error) {
EXIT;
return error;
}
dentry = nd.dentry;
error = -ENODEV;
if (!dentry->d_inode) {
EXIT;
goto out;
}
if (!S_ISCHR(dentry->d_inode->i_mode)) {
EXIT;
goto out;
}
devno = dentry->d_inode->i_rdev;
if ( MAJOR(devno) != PRESTO_PSDEV_MAJOR ) {
EXIT;
goto out;
}
if ( MINOR(devno) >= MAX_PRESTODEV ) {
EXIT;
goto out;
}
EXIT;
out:
*minor = MINOR(devno);
path_release(&nd);
return 0;
}
/* We always need to remove the presto options before passing to bottom FS */
struct super_block * presto_read_super(struct super_block * presto_sb,
void * data, int silent)
{
struct super_block *mysb = NULL;
struct file_system_type *fstype;
struct presto_cache *cache = NULL;
char *cache_data = NULL;
char *cache_data_end;
char *cache_type = NULL;
char *fileset = NULL;
char *presto_mtpt = NULL;
char *prestodev = NULL;
struct filter_fs *ops;
int minor;
struct upc_comm *psdev;
ENTRY;
CDEBUG(D_MALLOC, "before parsing: kmem %ld, vmem %ld\n",
presto_kmemory, presto_vmemory);
/* reserve space for the cache's data */
PRESTO_ALLOC(cache_data, void *, PAGE_SIZE);
if ( !cache_data ) {
printk("presto_read_super: Cannot allocate data page.\n");
EXIT;
goto out_err;
}
CDEBUG(D_SUPER, "mount opts: %s\n", data ? (char *)data : "(none)");
/* read and validate options */
cache_data_end = presto_options(data, cache_data, &cache_type, &fileset,
&prestodev, &presto_mtpt);
/* was there anything for the cache filesystem in the data? */
if (cache_data_end == cache_data) {
PRESTO_FREE(cache_data, PAGE_SIZE);
cache_data = NULL;
} else {
CDEBUG(D_SUPER, "cache_data at %p is: %s\n", cache_data,
cache_data);
}
/* prepare the communication channel */
if ( presto_get_minor(prestodev, &minor) ) {
/* if (!silent) */
printk("InterMezzo: %s not a valid presto dev\n", prestodev);
EXIT;
goto out_err;
}
psdev = &upc_comms[minor];
CDEBUG(D_SUPER, "\n");
psdev->uc_no_filter = 1;
CDEBUG(D_SUPER, "presto minor is %d\n", minor);
/* set up the cache */
cache = presto_init_cache();
if ( !cache ) {
printk("presto_read_super: failure allocating cache.\n");
EXIT;
goto out_err;
}
/* no options were passed: likely we are "/" readonly */
if ( !presto_mtpt || !fileset ) {
cache->cache_flags |= CACHE_LENTO_RO | CACHE_CLIENT_RO;
}
cache->cache_psdev = psdev;
/* no options were passed: likely we are "/" readonly */
/* before the journaling infrastructure can work, these
need to be set; that happens in presto_remount */
if ( !presto_mtpt || !fileset ) {
if (!presto_mtpt)
printk("No mountpoint marking cache RO\n");
if (!fileset)
printk("No fileset marking cache RO\n");
cache->cache_flags |= CACHE_LENTO_RO | CACHE_CLIENT_RO;
}
cache->cache_mtpt = presto_mtpt;
cache->cache_root_fileset = fileset;
cache->cache_type = cache_type;
printk("Presto: type=%s, vol=%s, dev=%s (minor %d), mtpt %s, flags %x\n",
cache_type, fileset ? fileset : "NULL", prestodev, minor,
presto_mtpt ? presto_mtpt : "NULL", cache->cache_flags);
MOD_INC_USE_COUNT;
fstype = get_fs_type(cache_type);
cache->cache_filter = filter_get_filter_fs((const char *)cache_type);
if ( !fstype || !cache->cache_filter) {
printk("Presto: unrecognized fs type or cache type\n");
MOD_DEC_USE_COUNT;
EXIT;
goto out_err;
}
mysb = fstype->read_super(presto_sb, cache_data, silent);
/* this might have been freed above */
if (cache_data) {
PRESTO_FREE(cache_data, PAGE_SIZE);
cache_data = NULL;
}
if ( !mysb ) {
/* if (!silent) */
printk("InterMezzo: cache mount failure.\n");
MOD_DEC_USE_COUNT;
EXIT;
goto out_err;
}
cache->cache_sb = mysb;
ops = filter_get_filter_fs(cache_type);
filter_setup_journal_ops(cache->cache_filter, cache->cache_type);
/* we now know the dev of the cache: hash the cache */
presto_cache_add(cache, mysb->s_dev);
/* make sure we have our own super operations: mysb
still contains the cache operations */
filter_setup_super_ops(cache->cache_filter, mysb->s_op,
&presto_super_ops);
mysb->s_op = filter_c2usops(cache->cache_filter);
/* now get our own directory operations */
if ( mysb->s_root && mysb->s_root->d_inode ) {
CDEBUG(D_SUPER, "\n");
filter_setup_dir_ops(cache->cache_filter,
mysb->s_root->d_inode,
&presto_dir_iops, &presto_dir_fops);
mysb->s_root->d_inode->i_op = filter_c2udiops(cache->cache_filter);
CDEBUG(D_SUPER, "lookup at %p\n",
mysb->s_root->d_inode->i_op->lookup);
filter_setup_dentry_ops(cache->cache_filter,
mysb->s_root->d_op,
&presto_dentry_ops);
presto_sb->s_root->d_op = filter_c2udops(cache->cache_filter);
cache->cache_mtde = mysb->s_root;
}
CDEBUG(D_MALLOC, "after mounting: kmem %ld, vmem %ld\n",
presto_kmemory, presto_vmemory);
EXIT;
return mysb;
out_err:
CDEBUG(D_SUPER, "out_err called\n");
if (cache)
PRESTO_FREE(cache, sizeof(struct presto_cache));
if (cache_data)
PRESTO_FREE(cache_data, PAGE_SIZE);
if (fileset)
PRESTO_FREE(fileset, strlen(fileset) + 1);
if (presto_mtpt)
PRESTO_FREE(presto_mtpt, strlen(presto_mtpt) + 1);
if (prestodev)
PRESTO_FREE(prestodev, strlen(prestodev) + 1);
if (cache_type)
PRESTO_FREE(cache_type, strlen(cache_type) + 1);
CDEBUG(D_MALLOC, "mount error exit: kmem %ld, vmem %ld\n",
presto_kmemory, presto_vmemory);
return NULL;
}
int presto_remount(struct super_block * sb, int *flags, char *data)
{
char *cache_data = NULL;
char *cache_data_end;
char **type;
char **fileset;
char **mtpt;
char **prestodev;
struct super_operations *sops;
struct presto_cache *cache = NULL;
int err = 0;
ENTRY;
CDEBUG(D_MALLOC, "before remount: kmem %ld, vmem %ld\n",
presto_kmemory, presto_vmemory);
CDEBUG(D_SUPER, "remount opts: %s\n", data ? (char *)data : "(none)");
if (data) {
/* reserve space for the cache's data */
PRESTO_ALLOC(cache_data, void *, PAGE_SIZE);
if ( !cache_data ) {
err = -ENOMEM;
EXIT;
goto out_err;
}
}
cache = presto_find_cache(sb->s_dev);
if (!cache) {
printk(__FUNCTION__ ": cannot find cache on remount\n");
err = -ENODEV;
EXIT;
goto out_err;
}
/* If an option has not yet been set, we allow it to be set on
* remount. If an option already has a value, we pass NULL for
* the option pointer, which means that the InterMezzo option
* will be parsed but discarded.
*/
type = cache->cache_type ? NULL : &cache->cache_type;
fileset = cache->cache_root_fileset ? NULL : &cache->cache_root_fileset;
prestodev = cache->cache_psdev ? NULL : &cache->cache_psdev->uc_devname;
mtpt = cache->cache_mtpt ? NULL : &cache->cache_mtpt;
cache_data_end = presto_options(data, cache_data, type, fileset,
prestodev, mtpt);
if (cache_data) {
if (cache_data_end == cache_data) {
PRESTO_FREE(cache_data, PAGE_SIZE);
cache_data = NULL;
} else {
CDEBUG(D_SUPER, "cache_data at %p is: %s\n", cache_data,
cache_data);
}
}
if (cache->cache_root_fileset && cache->cache_mtpt) {
cache->cache_flags &= ~(CACHE_LENTO_RO|CACHE_CLIENT_RO);
}
sops = filter_c2csops(cache->cache_filter);
if (sops->remount_fs) {
err = sops->remount_fs(sb, flags, cache_data);
}
CDEBUG(D_MALLOC, "after remount: kmem %ld, vmem %ld\n",
presto_kmemory, presto_vmemory);
EXIT;
out_err:
if (cache_data)
PRESTO_FREE(cache_data, PAGE_SIZE);
return err;
}
struct file_system_type presto_fs_type = {
#ifdef PRESTO_DEVEL
"izofs",
#else
"intermezzo",
#endif
FS_REQUIRES_DEV, /* can use Ibaskets when ext2 does */
presto_read_super,
NULL
};
int /* __init */ init_intermezzo_fs(void)
{
int status;
printk(KERN_INFO "InterMezzo Kernel/Lento communications, "
"v1.04, braam@inter-mezzo.org\n");
status = presto_psdev_init();
if ( status ) {
printk("Problem (%d) in init_intermezzo_psdev\n", status);
return status;
}
status = init_intermezzo_sysctl();
if (status) {
printk("presto: failed in init_intermezzo_sysctl!\n");
}
presto_init_cache_hash();
status = register_filesystem(&presto_fs_type);
if (status) {
printk("presto: failed in register_filesystem!\n");
}
return status;
}
#ifdef MODULE
MODULE_AUTHOR("Peter J. Braam <braam@inter-mezzo.org>");
MODULE_DESCRIPTION("InterMezzo Kernel/Lento communications, v1.0.5.1");
int init_module(void)
{
return init_intermezzo_fs();
}
void cleanup_module(void)
{
int err;
ENTRY;
if ( (err = unregister_filesystem(&presto_fs_type)) != 0 ) {
printk("presto: failed to unregister filesystem\n");
}
presto_psdev_cleanup();
cleanup_intermezzo_sysctl();
#ifdef PRESTO_DEVEL
unregister_chrdev(PRESTO_PSDEV_MAJOR, "intermezzo_psdev_devel");
#else
unregister_chrdev(PRESTO_PSDEV_MAJOR, "intermezzo_psdev");
#endif
CDEBUG(D_MALLOC, "after cleanup: kmem %ld, vmem %ld\n",
presto_kmemory, presto_vmemory);
}
#endif
|