351 строка
8.1 KiB
C
351 строка
8.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* super.c
|
|
*
|
|
* Copyright (c) 1999 Al Smith
|
|
*
|
|
* Portions derived from work (c) 1995,1996 Christian Vogelgsang.
|
|
*/
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/module.h>
|
|
#include <linux/exportfs.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/buffer_head.h>
|
|
#include <linux/vfs.h>
|
|
|
|
#include "efs.h"
|
|
#include <linux/efs_vh.h>
|
|
#include <linux/efs_fs_sb.h>
|
|
|
|
static int efs_statfs(struct dentry *dentry, struct kstatfs *buf);
|
|
static int efs_fill_super(struct super_block *s, void *d, int silent);
|
|
|
|
static struct dentry *efs_mount(struct file_system_type *fs_type,
|
|
int flags, const char *dev_name, void *data)
|
|
{
|
|
return mount_bdev(fs_type, flags, dev_name, data, efs_fill_super);
|
|
}
|
|
|
|
static void efs_kill_sb(struct super_block *s)
|
|
{
|
|
struct efs_sb_info *sbi = SUPER_INFO(s);
|
|
kill_block_super(s);
|
|
kfree(sbi);
|
|
}
|
|
|
|
static struct file_system_type efs_fs_type = {
|
|
.owner = THIS_MODULE,
|
|
.name = "efs",
|
|
.mount = efs_mount,
|
|
.kill_sb = efs_kill_sb,
|
|
.fs_flags = FS_REQUIRES_DEV,
|
|
};
|
|
MODULE_ALIAS_FS("efs");
|
|
|
|
static struct pt_types sgi_pt_types[] = {
|
|
{0x00, "SGI vh"},
|
|
{0x01, "SGI trkrepl"},
|
|
{0x02, "SGI secrepl"},
|
|
{0x03, "SGI raw"},
|
|
{0x04, "SGI bsd"},
|
|
{SGI_SYSV, "SGI sysv"},
|
|
{0x06, "SGI vol"},
|
|
{SGI_EFS, "SGI efs"},
|
|
{0x08, "SGI lv"},
|
|
{0x09, "SGI rlv"},
|
|
{0x0A, "SGI xfs"},
|
|
{0x0B, "SGI xfslog"},
|
|
{0x0C, "SGI xlv"},
|
|
{0x82, "Linux swap"},
|
|
{0x83, "Linux native"},
|
|
{0, NULL}
|
|
};
|
|
|
|
|
|
static struct kmem_cache * efs_inode_cachep;
|
|
|
|
static struct inode *efs_alloc_inode(struct super_block *sb)
|
|
{
|
|
struct efs_inode_info *ei;
|
|
ei = kmem_cache_alloc(efs_inode_cachep, GFP_KERNEL);
|
|
if (!ei)
|
|
return NULL;
|
|
return &ei->vfs_inode;
|
|
}
|
|
|
|
static void efs_free_inode(struct inode *inode)
|
|
{
|
|
kmem_cache_free(efs_inode_cachep, INODE_INFO(inode));
|
|
}
|
|
|
|
static void init_once(void *foo)
|
|
{
|
|
struct efs_inode_info *ei = (struct efs_inode_info *) foo;
|
|
|
|
inode_init_once(&ei->vfs_inode);
|
|
}
|
|
|
|
static int __init init_inodecache(void)
|
|
{
|
|
efs_inode_cachep = kmem_cache_create("efs_inode_cache",
|
|
sizeof(struct efs_inode_info), 0,
|
|
SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
|
|
SLAB_ACCOUNT, init_once);
|
|
if (efs_inode_cachep == NULL)
|
|
return -ENOMEM;
|
|
return 0;
|
|
}
|
|
|
|
static void destroy_inodecache(void)
|
|
{
|
|
/*
|
|
* Make sure all delayed rcu free inodes are flushed before we
|
|
* destroy cache.
|
|
*/
|
|
rcu_barrier();
|
|
kmem_cache_destroy(efs_inode_cachep);
|
|
}
|
|
|
|
static int efs_remount(struct super_block *sb, int *flags, char *data)
|
|
{
|
|
sync_filesystem(sb);
|
|
*flags |= SB_RDONLY;
|
|
return 0;
|
|
}
|
|
|
|
static const struct super_operations efs_superblock_operations = {
|
|
.alloc_inode = efs_alloc_inode,
|
|
.free_inode = efs_free_inode,
|
|
.statfs = efs_statfs,
|
|
.remount_fs = efs_remount,
|
|
};
|
|
|
|
static const struct export_operations efs_export_ops = {
|
|
.fh_to_dentry = efs_fh_to_dentry,
|
|
.fh_to_parent = efs_fh_to_parent,
|
|
.get_parent = efs_get_parent,
|
|
};
|
|
|
|
static int __init init_efs_fs(void) {
|
|
int err;
|
|
pr_info(EFS_VERSION" - http://aeschi.ch.eu.org/efs/\n");
|
|
err = init_inodecache();
|
|
if (err)
|
|
goto out1;
|
|
err = register_filesystem(&efs_fs_type);
|
|
if (err)
|
|
goto out;
|
|
return 0;
|
|
out:
|
|
destroy_inodecache();
|
|
out1:
|
|
return err;
|
|
}
|
|
|
|
static void __exit exit_efs_fs(void) {
|
|
unregister_filesystem(&efs_fs_type);
|
|
destroy_inodecache();
|
|
}
|
|
|
|
module_init(init_efs_fs)
|
|
module_exit(exit_efs_fs)
|
|
|
|
static efs_block_t efs_validate_vh(struct volume_header *vh) {
|
|
int i;
|
|
__be32 cs, *ui;
|
|
int csum;
|
|
efs_block_t sblock = 0; /* shuts up gcc */
|
|
struct pt_types *pt_entry;
|
|
int pt_type, slice = -1;
|
|
|
|
if (be32_to_cpu(vh->vh_magic) != VHMAGIC) {
|
|
/*
|
|
* assume that we're dealing with a partition and allow
|
|
* read_super() to try and detect a valid superblock
|
|
* on the next block.
|
|
*/
|
|
return 0;
|
|
}
|
|
|
|
ui = ((__be32 *) (vh + 1)) - 1;
|
|
for(csum = 0; ui >= ((__be32 *) vh);) {
|
|
cs = *ui--;
|
|
csum += be32_to_cpu(cs);
|
|
}
|
|
if (csum) {
|
|
pr_warn("SGI disklabel: checksum bad, label corrupted\n");
|
|
return 0;
|
|
}
|
|
|
|
#ifdef DEBUG
|
|
pr_debug("bf: \"%16s\"\n", vh->vh_bootfile);
|
|
|
|
for(i = 0; i < NVDIR; i++) {
|
|
int j;
|
|
char name[VDNAMESIZE+1];
|
|
|
|
for(j = 0; j < VDNAMESIZE; j++) {
|
|
name[j] = vh->vh_vd[i].vd_name[j];
|
|
}
|
|
name[j] = (char) 0;
|
|
|
|
if (name[0]) {
|
|
pr_debug("vh: %8s block: 0x%08x size: 0x%08x\n",
|
|
name, (int) be32_to_cpu(vh->vh_vd[i].vd_lbn),
|
|
(int) be32_to_cpu(vh->vh_vd[i].vd_nbytes));
|
|
}
|
|
}
|
|
#endif
|
|
|
|
for(i = 0; i < NPARTAB; i++) {
|
|
pt_type = (int) be32_to_cpu(vh->vh_pt[i].pt_type);
|
|
for(pt_entry = sgi_pt_types; pt_entry->pt_name; pt_entry++) {
|
|
if (pt_type == pt_entry->pt_type) break;
|
|
}
|
|
#ifdef DEBUG
|
|
if (be32_to_cpu(vh->vh_pt[i].pt_nblks)) {
|
|
pr_debug("pt %2d: start: %08d size: %08d type: 0x%02x (%s)\n",
|
|
i, (int)be32_to_cpu(vh->vh_pt[i].pt_firstlbn),
|
|
(int)be32_to_cpu(vh->vh_pt[i].pt_nblks),
|
|
pt_type, (pt_entry->pt_name) ?
|
|
pt_entry->pt_name : "unknown");
|
|
}
|
|
#endif
|
|
if (IS_EFS(pt_type)) {
|
|
sblock = be32_to_cpu(vh->vh_pt[i].pt_firstlbn);
|
|
slice = i;
|
|
}
|
|
}
|
|
|
|
if (slice == -1) {
|
|
pr_notice("partition table contained no EFS partitions\n");
|
|
#ifdef DEBUG
|
|
} else {
|
|
pr_info("using slice %d (type %s, offset 0x%x)\n", slice,
|
|
(pt_entry->pt_name) ? pt_entry->pt_name : "unknown",
|
|
sblock);
|
|
#endif
|
|
}
|
|
return sblock;
|
|
}
|
|
|
|
static int efs_validate_super(struct efs_sb_info *sb, struct efs_super *super) {
|
|
|
|
if (!IS_EFS_MAGIC(be32_to_cpu(super->fs_magic)))
|
|
return -1;
|
|
|
|
sb->fs_magic = be32_to_cpu(super->fs_magic);
|
|
sb->total_blocks = be32_to_cpu(super->fs_size);
|
|
sb->first_block = be32_to_cpu(super->fs_firstcg);
|
|
sb->group_size = be32_to_cpu(super->fs_cgfsize);
|
|
sb->data_free = be32_to_cpu(super->fs_tfree);
|
|
sb->inode_free = be32_to_cpu(super->fs_tinode);
|
|
sb->inode_blocks = be16_to_cpu(super->fs_cgisize);
|
|
sb->total_groups = be16_to_cpu(super->fs_ncg);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int efs_fill_super(struct super_block *s, void *d, int silent)
|
|
{
|
|
struct efs_sb_info *sb;
|
|
struct buffer_head *bh;
|
|
struct inode *root;
|
|
|
|
sb = kzalloc(sizeof(struct efs_sb_info), GFP_KERNEL);
|
|
if (!sb)
|
|
return -ENOMEM;
|
|
s->s_fs_info = sb;
|
|
s->s_time_min = 0;
|
|
s->s_time_max = U32_MAX;
|
|
|
|
s->s_magic = EFS_SUPER_MAGIC;
|
|
if (!sb_set_blocksize(s, EFS_BLOCKSIZE)) {
|
|
pr_err("device does not support %d byte blocks\n",
|
|
EFS_BLOCKSIZE);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* read the vh (volume header) block */
|
|
bh = sb_bread(s, 0);
|
|
|
|
if (!bh) {
|
|
pr_err("cannot read volume header\n");
|
|
return -EIO;
|
|
}
|
|
|
|
/*
|
|
* if this returns zero then we didn't find any partition table.
|
|
* this isn't (yet) an error - just assume for the moment that
|
|
* the device is valid and go on to search for a superblock.
|
|
*/
|
|
sb->fs_start = efs_validate_vh((struct volume_header *) bh->b_data);
|
|
brelse(bh);
|
|
|
|
if (sb->fs_start == -1) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
bh = sb_bread(s, sb->fs_start + EFS_SUPER);
|
|
if (!bh) {
|
|
pr_err("cannot read superblock\n");
|
|
return -EIO;
|
|
}
|
|
|
|
if (efs_validate_super(sb, (struct efs_super *) bh->b_data)) {
|
|
#ifdef DEBUG
|
|
pr_warn("invalid superblock at block %u\n",
|
|
sb->fs_start + EFS_SUPER);
|
|
#endif
|
|
brelse(bh);
|
|
return -EINVAL;
|
|
}
|
|
brelse(bh);
|
|
|
|
if (!sb_rdonly(s)) {
|
|
#ifdef DEBUG
|
|
pr_info("forcing read-only mode\n");
|
|
#endif
|
|
s->s_flags |= SB_RDONLY;
|
|
}
|
|
s->s_op = &efs_superblock_operations;
|
|
s->s_export_op = &efs_export_ops;
|
|
root = efs_iget(s, EFS_ROOTINODE);
|
|
if (IS_ERR(root)) {
|
|
pr_err("get root inode failed\n");
|
|
return PTR_ERR(root);
|
|
}
|
|
|
|
s->s_root = d_make_root(root);
|
|
if (!(s->s_root)) {
|
|
pr_err("get root dentry failed\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int efs_statfs(struct dentry *dentry, struct kstatfs *buf) {
|
|
struct super_block *sb = dentry->d_sb;
|
|
struct efs_sb_info *sbi = SUPER_INFO(sb);
|
|
u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
|
|
|
|
buf->f_type = EFS_SUPER_MAGIC; /* efs magic number */
|
|
buf->f_bsize = EFS_BLOCKSIZE; /* blocksize */
|
|
buf->f_blocks = sbi->total_groups * /* total data blocks */
|
|
(sbi->group_size - sbi->inode_blocks);
|
|
buf->f_bfree = sbi->data_free; /* free data blocks */
|
|
buf->f_bavail = sbi->data_free; /* free blocks for non-root */
|
|
buf->f_files = sbi->total_groups * /* total inodes */
|
|
sbi->inode_blocks *
|
|
(EFS_BLOCKSIZE / sizeof(struct efs_dinode));
|
|
buf->f_ffree = sbi->inode_free; /* free inodes */
|
|
buf->f_fsid.val[0] = (u32)id;
|
|
buf->f_fsid.val[1] = (u32)(id >> 32);
|
|
buf->f_namelen = EFS_MAXNAMELEN; /* max filename length */
|
|
|
|
return 0;
|
|
}
|
|
|