- 根目录:
- fs
- qnx6
- inode.c
/*
* QNX6 file system, Linux implementation.
*
* Version : 1.0.0
*
* History :
*
* 01-02-2012 by Kai Bankett (chaosman@ontika.net) : first release.
* 16-02-2012 pagemap extension by Al Viro
*
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/highuid.h>
#include <linux/pagemap.h>
#include <linux/buffer_head.h>
#include <linux/writeback.h>
#include <linux/statfs.h>
#include <linux/parser.h>
#include <linux/seq_file.h>
#include <linux/mount.h>
#include <linux/crc32.h>
#include <linux/mpage.h>
#include "qnx6.h"
static const struct super_operations qnx6_sops;
static void qnx6_put_super(struct super_block *sb);
static struct inode *qnx6_alloc_inode(struct super_block *sb);
static void qnx6_destroy_inode(struct inode *inode);
static int qnx6_remount(struct super_block *sb, int *flags, char *data);
static int qnx6_statfs(struct dentry *dentry, struct kstatfs *buf);
static int qnx6_show_options(struct seq_file *seq, struct dentry *root);
static const struct super_operations qnx6_sops = {
.alloc_inode = qnx6_alloc_inode,
.destroy_inode = qnx6_destroy_inode,
.put_super = qnx6_put_super,
.statfs = qnx6_statfs,
.remount_fs = qnx6_remount,
.show_options = qnx6_show_options,
};
static int qnx6_show_options(struct seq_file *seq, struct dentry *root)
{
struct super_block *sb = root->d_sb;
struct qnx6_sb_info *sbi = QNX6_SB(sb);
if (sbi->s_mount_opt & QNX6_MOUNT_MMI_FS)
seq_puts(seq, ",mmi_fs");
return 0;
}
static int qnx6_remount(struct super_block *sb, int *flags, char *data)
{
*flags |= MS_RDONLY;
return 0;
}
static unsigned qnx6_get_devblock(struct super_block *sb, __fs32 block)
{
struct qnx6_sb_info *sbi = QNX6_SB(sb);
return fs32_to_cpu(sbi, block) + sbi->s_blks_off;
}
static unsigned qnx6_block_map(struct inode *inode, unsigned iblock);
static int qnx6_get_block(struct inode *inode, sector_t iblock,
struct buffer_head *bh, int create)
{
unsigned phys;
QNX6DEBUG((KERN_INFO "qnx6: qnx6_get_block inode=[%ld] iblock=[%ld]\n",
inode->i_ino, (unsigned long)iblock));
phys = qnx6_block_map(inode, iblock);
if (phys) {
/* logical block is before EOF */
map_bh(bh, inode->i_sb, phys);
}
return 0;
}
static int qnx6_check_blockptr(__fs32 ptr)
{
if (ptr == ~(__fs32)0) {
printk(KERN_ERR "qnx6: hit unused blockpointer.\n");
return 0;
}
return 1;
}
static int qnx6_readpage(struct file *file, struct page *page)
{
return mpage_readpage(page, qnx6_get_block);
}
static int qnx6_readpages(struct file *file, struct address_space *mapping,
struct list_head *pages, unsigned nr_pages)
{
return mpage_readpages(mapping, pages, nr_pages, qnx6_get_block);
}
/*
* returns the block number for the no-th element in the tree
* inodebits requred as there are multiple inodes in one inode block
*/
static unsigned qnx6_block_map(struct inode *inode, unsigned no)
{
struct super_block *s = inode->i_sb;
struct qnx6_sb_info *sbi = QNX6_SB(s);
struct qnx6_inode_info *ei = QNX6_I(inode);
unsigned block = 0;
struct buffer_head *bh;
__fs32 ptr;
int levelptr;
int ptrbits = sbi->s_ptrbits;
int bitdelta;
u32 mask = (1 << ptrbits) - 1;
int depth = ei->di_filelevels;
int i;
bitdelta = ptrbits * depth;
levelptr = no >> bitdelta;
if (levelptr > QNX6_NO_DIRECT_POINTERS - 1) {
printk(KERN_ERR "qnx6:Requested file block number (%u) too big.",
no);
return 0;
}
block = qnx6_get_devblock(s, ei->di_block_ptr[levelptr]);
for (i = 0; i < depth; i++) {
bh = sb_bread(s, block);
if (!bh) {
printk(KERN_ERR "qnx6:Error reading block (%u)\n",
block);
return 0;
}
bitdelta -= ptrbits;
levelptr = (no >> bitdelta) & mask;
ptr = ((__fs32 *)bh->b_data)[levelptr];
if (!qnx6_check_blockptr(ptr))
return 0;
block = qnx6_get_devblock(s, ptr);
brelse(bh);
}
return block;
}
static int qnx6_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct super_block *sb = dentry->d_sb;
struct qnx6_sb_info *sbi = QNX6_SB(sb);
u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
buf->f_type = sb->s_magic;
buf->f_bsize = sb->s_blocksize;
buf->f_blocks = fs32_to_cpu(sbi, sbi->sb->sb_num_blocks);
buf->f_bfree = fs32_to_cpu(sbi, sbi->sb->sb_free_blocks);
buf->f_files = fs32_to_cpu(sbi, sbi->sb->sb_num_inodes);
buf->f_ffree = fs32_to_cpu(sbi, sbi->sb->sb_free_inodes);
buf->f_bavail = buf->f_bfree;
buf->f_namelen = QNX6_LONG_NAME_MAX;
buf->f_fsid.val[0] = (u32)id;
buf->f_fsid.val[1] = (u32)(id >> 32);
return 0;
}
/*
* Check the root directory of the filesystem to make sure
* it really _is_ a qnx6 filesystem, and to check the size
* of the directory entry.
*/
static const char *qnx6_checkroot(struct super_block *s)
{
static char match_root[2][3] = {".\0\0", "..\0"};
int i, error = 0;
struct qnx6_dir_entry *dir_entry;
struct inode *root = s->s_root->d_inode;
struct address_space *mapping = root->i_mapping;
struct page *page = read_mapping_page(mapping, 0, NULL);
if (IS_ERR(page))
return "error reading root directory";
kmap(page);
dir_entry = page_address(page);
for (i = 0; i < 2; i++) {
/* maximum 3 bytes - due to match_root limitation */
if (strncmp(dir_entry[i].de_fname, match_root[i], 3))
error = 1;
}
qnx6_put_page(page);
if (error)
return "error reading root directory.";
return NULL;
}
#ifdef CONFIG_QNX6FS_DEBUG
void qnx6_superblock_debug(struct qnx6_super_block *sb, struct super_block *s)
{
struct qnx6_sb_info *sbi = QNX6_SB(s);
QNX6DEBUG((KERN_INFO "magic: %08x\n",
fs32_to_cpu(sbi, sb->sb_magic)));
QNX6DEBUG((KERN_INFO "checksum: %08x\n",
fs32_to_cpu(sbi, sb->sb_checksum)));
QNX6DEBUG((KERN_INFO "serial: %llx\n",
fs64_to_cpu(sbi, sb->sb_serial)));
QNX6DEBUG((KERN_INFO "flags: %08x\n",
fs32_to_cpu(sbi, sb->sb_flags)));
QNX6DEBUG((KERN_INFO "blocksize: %08x\n",
fs32_to_cpu(sbi, sb->sb_blocksize)));
QNX6DEBUG((KERN_INFO "num_inodes: %08x\n",
fs32_to_cpu(sbi, sb->sb_num_inodes)));
QNX6DEBUG((KERN_INFO "free_inodes: %08x\n",
fs32_to_cpu(sbi, sb->sb_free_inodes)));
QNX6DEBUG((KERN_INFO "num_blocks: %08x\n",
fs32_to_cpu(sbi, sb->sb_num_blocks)));
QNX6DEBUG((KERN_INFO "free_blocks: %08x\n",
fs32_to_cpu(sbi, sb->sb_free_blocks)));
QNX6DEBUG((KERN_INFO "inode_levels: %02x\n",
sb->Inode.levels));
}
#endif
enum {
Opt_mmifs,
Opt_err
};
static const match_table_t tokens = {
{Opt_mmifs, "mmi_fs"},
{Opt_err, NULL}
};
static int qnx6_parse_options(char *options, struct super_block *sb)
{
char *p;
struct qnx6_sb_info *sbi = QNX6_SB(sb);
substring_t args[MAX_OPT_ARGS];
if (!options)
return 1;
while ((p = strsep(&options, ",")) != NULL) {
int token;
if (!*p)
continue;
token = match_token(p, tokens, args);
switch (token) {
case Opt_mmifs:
set_opt(sbi->s_mount_opt, MMI_FS);
break;
default:
return 0;
}
}
return 1;
}
static struct buffer_head *qnx6_check_first_superblock(struct super_block *s,
int offset, int silent)
{
struct qnx6_sb_info *sbi = QNX6_SB(s);
struct buffer_head *bh;
struct qnx6_super_block *sb;
/* Check the superblock signatures
start with the first superblock */
bh = sb_bread(s, offset);
if (!bh) {
printk(KERN_ERR "qnx6: unable to read the first superblock\n");
return NULL;
}
sb = (struct qnx6_super_block *)bh->b_data;
if (fs32_to_cpu(sbi, sb->sb_magic) != QNX6_SUPER_MAGIC) {
sbi->s_bytesex = BYTESEX_BE;
if (fs32_to_cpu(sbi, sb->sb_magic) == QNX6_SUPER_MAGIC) {
/* we got a big endian fs */
QNX6DEBUG((KERN_INFO "qnx6: fs got different"
" endianess.\n"));
return bh;
} else
sbi->s_bytesex = BYTESEX_LE;
if (!silent) {
if (offset == 0) {
printk(KERN_ERR "qnx6: wrong signature (magic)"
" in superblock #1.\n");
} else {
printk(KERN_INFO "qnx6: wrong signature (magic)"
" at position (0x%lx) - will try"
" alternative position (0x0000).\n",
offset * s->s_blocksize);
}
}
brelse(bh);
return NULL;
}
return bh;
}
static struct inode *qnx6_private_inode(struct super_block *s,
struct qnx6_root_node *p);
static int qnx6_fill_super(struct super_block *s, void *data, int silent)
{
struct buffer_head *bh1 = NULL, *bh2 = NULL;
struct qnx6_super_block *sb1 = NULL, *sb2 = NULL;
struct qnx6_sb_info *sbi;
struct inode *root;
const char *errmsg;
struct qnx6_sb_info *qs;
int ret = -EINVAL;
u64 offset;
int bootblock_offset = QNX6_BOOTBLOCK_SIZE;
qs = kzalloc(sizeof(struct qnx6_sb_info), GFP_KERNEL);
if (!qs)
return -ENOMEM;
s->s_fs_info = qs;
/* Superblock always is 512 Byte long */
if (!sb_set_blocksize(s, QNX6_SUPERBLOCK_SIZE)) {
printk(KERN_ERR "qnx6: unable to set blocksize\n");
goto outnobh;
}
/* parse the mount-options */
if (!qnx6_parse_options((char *) data, s)) {
printk(KERN_ERR "qnx6: invalid mount options.\n");
goto outnobh;
}
if (test_opt(s, MMI_FS)) {
sb1 = qnx6_mmi_fill_super(s, silent);
if (sb1)
goto mmi_success;
else
goto outnobh;
}
sbi = QNX6_SB(s);
sbi->s_bytesex = BYTESEX_LE;
/* Check the superblock signatures
start with the first superblock */
bh1 = qnx6_check_first_superblock(s,
bootblock_offset / QNX6_SUPERBLOCK_SIZE, silent);
if (!bh1) {
/* try again without bootblock offset */
bh1 = qnx6_check_first_superblock(s, 0, silent);
if (!bh1) {
printk(KERN_ERR "qnx6: unable to read the first superblock\n");
goto outnobh;
}
/* seems that no bootblock at partition start */
bootblock_offset = 0;
}
sb1 = (struct qnx6_super_block *)bh1->b_data;
#ifdef CONFIG_QNX6FS_DEBUG
qnx6_superblock_debug(sb1, s);
#endif
/* checksum check - start at byte 8 and end at byte 512 */
if (fs32_to_cpu(sbi, sb1->sb_checksum) !=
crc32_be(0, (char *)(bh1->b_data + 8), 504)) {
printk(KERN_ERR "qnx6: superblock #1 checksum error\n");
goto out;
}
/* set new blocksize */
if (!sb_set_blocksize(s, fs32_to_cpu(sbi, sb1->sb_blocksize))) {
printk(KERN_ERR "qnx6: unable to set blocksize\n");
goto out;
}
/* blocksize invalidates bh - pull it back in */
brelse(bh1);
bh1 = sb_bread(s, bootblock_offset >> s->s_blocksize_bits);
if (!bh1)
goto outnobh;
sb1 = (struct qnx6_super_block *)bh1->b_data;
/* calculate second superblock blocknumber */
offset = fs32_to_cpu(sbi, sb1->sb_num_blocks) +
(bootblock_offset >> s->s_blocksize_bits) +
(QNX6_SUPERBLOCK_AREA >> s->s_blocksize_bits);
/* set bootblock offset */
sbi->s_blks_off = (bootblock_offset >> s->s_blocksize_bits) +
(QNX6_SUPERBLOCK_AREA >> s->s_blocksize_bits);
/* next the second superblock */
bh2 = sb_bread(s, offset);
if (!bh2) {
printk(KERN_ERR "qnx6: unable to read the second superblock\n");
goto out;
}
sb2 = (struct qnx6_super_block *)bh2->b_data;
if (fs32_to_cpu(sbi, sb2->sb_magic) != QNX6_SUPER_MAGIC) {
if (!silent)
printk(KERN_ERR "qnx6: wrong signature (magic)"
" in superblock #2.\n");
goto out;
}
/* checksum check - start at byte 8 and end at byte 512 */
if (fs32_to_cpu(sbi, sb2->sb_checksum) !=
crc32_be(0, (char *)(bh2->b_data + 8), 504)) {
printk(KERN_ERR "qnx6: superblock #2 checksum error\n");
goto out;
}
if (fs64_to_cpu(sbi, sb1->sb_serial) >=
fs64_to_cpu(sbi, sb2->sb_serial)) {
/* superblock #1 active */
sbi->sb_buf = bh1;
sbi->sb = (struct qnx6_super_block *)bh1->b_data;
brelse(bh2);
printk(KERN_INFO "qnx6: superblock #1 active\n");
} else {
/* superblock #2 active */
sbi->sb_buf = bh2;
sbi->sb = (struct qnx6_super_block *)bh2->b_data;
brelse(bh1);
printk(KERN_INFO "qnx6: superblock #2 active\n");
}
mmi_success:
/* sanity check - limit maximum indirect pointer levels */
if (sb1->Inode.levels > QNX6_PTR_MAX_LEVELS) {
printk(KERN_ERR "qnx6: too many inode levels (max %i, sb %i)\n",
QNX6_PTR_MAX_LEVELS, sb1->Inode.levels);
goto out;
}
if (sb1->Longfile.levels > QNX6_PTR_MAX_LEVELS) {
printk(KERN_ERR "qnx6: too many longfilename levels"
" (max %i, sb %i)\n",
QNX6_PTR_MAX_LEVELS, sb1->Longfile.levels);
goto out;
}
s->s_op = &qnx6_sops;
s->s_magic = QNX6_SUPER_MAGIC;
s->s_flags |= MS_RDONLY; /* Yup, read-only yet */
/* ease the later tree level calculations */
sbi = QNX6_SB(s);
sbi->s_ptrbits = ilog2(s->s_blocksize / 4);
sbi->inodes = qnx6_private_inode(s, &sb1->Inode);
if (!sbi->inodes)
goto out;
sbi->longfile = qnx6_private_inode(s, &sb1->Longfile);
if (!sbi->longfile)
goto out1;
/* prefetch root inode */
root = qnx6_iget(s, QNX6_ROOT_INO);
if (IS_ERR(root)) {
printk(KERN_ERR "qnx6: get inode failed\n");
ret = PTR_ERR(root);
goto out2;
}
ret = -ENOMEM;
s->s_root = d_make_root(root);
if (!s->s_root)
goto out2;
ret = -EINVAL;
errmsg = qnx6_checkroot(s);
if (errmsg != NULL) {
if (!silent)
printk(KERN_ERR "qnx6: %s\n", errmsg);
goto out3;
}
return 0;
out3:
dput(s->s_root);
s->s_root = NULL;
out2:
iput(sbi->longfile);
out1:
iput(sbi->inodes);
out:
if (bh1)
brelse(bh1);
if (bh2)
brelse(bh2);
outnobh:
kfree(qs);
s->s_fs_info = NULL;
return ret;
}
static void qnx6_put_super(struct super_block *sb)
{
struct qnx6_sb_info *qs = QNX6_SB(sb);
brelse(qs->sb_buf);
iput(qs->longfile);
iput(qs->inodes);
kfree(qs);
sb->s_fs_info = NULL;
return;
}
static sector_t qnx6_bmap(struct address_space *mapping, sector_t block)
{
return generic_block_bmap(mapping, block, qnx6_get_block);
}
static const struct address_space_operations qnx6_aops = {
.readpage = qnx6_readpage,
.readpages = qnx6_readpages,
.bmap = qnx6_bmap
};
static struct inode *qnx6_private_inode(struct super_block *s,
struct qnx6_root_node *p)
{
struct inode *inode = new_inode(s);
if (inode) {
struct qnx6_inode_info *ei = QNX6_I(inode);
struct qnx6_sb_info *sbi = QNX6_SB(s);
inode->i_size = fs64_to_cpu(sbi, p->size);
memcpy(ei->di_block_ptr, p->ptr, sizeof(p->ptr));
ei->di_filelevels = p->levels;
inode->i_mode = S_IFREG | S_IRUSR; /* probably wrong */
inode->i_mapping->a_ops = &qnx6_aops;
}
return inode;
}
struct inode *qnx6_iget(struct super_block *sb, unsigned ino)
{
struct qnx6_sb_info *sbi = QNX6_SB(sb);
struct qnx6_inode_entry *raw_inode;
struct inode *inode;
struct qnx6_inode_info *ei;
struct address_space *mapping;
struct page *page;
u32 n, offs;
inode = iget_locked(sb, ino);
if (!inode)
return ERR_PTR(-ENOMEM);
if (!(inode->i_state & I_NEW))
return inode;
ei = QNX6_I(inode);
inode->i_mode = 0;
if (ino == 0) {
printk(KERN_ERR "qnx6: bad inode number on dev %s: %u is "
"out of range\n",
sb->s_id, ino);
iget_failed(inode);
return ERR_PTR(-EIO);
}
n = (ino - 1) >> (PAGE_CACHE_SHIFT - QNX6_INODE_SIZE_BITS);
offs = (ino - 1) & (~PAGE_CACHE_MASK >> QNX6_INODE_SIZE_BITS);
mapping = sbi->inodes->i_mapping;
page = read_mapping_page(mapping, n, NULL);
if (IS_ERR(page)) {
printk(KERN_ERR "qnx6: major problem: unable to read inode from "
"dev %s\n", sb->s_id);
iget_failed(inode);
return ERR_CAST(page);
}
kmap(page);
raw_inode = ((struct qnx6_inode_entry *)page_address(page)) + offs;
inode->i_mode = fs16_to_cpu(sbi, raw_inode->di_mode);
inode->i_uid = (uid_t)fs32_to_cpu(sbi, raw_inode->di_uid);
inode->i_gid = (gid_t)fs32_to_cpu(sbi, raw_inode->di_gid);
inode->i_size = fs64_to_cpu(sbi, raw_inode->di_size);
inode->i_mtime.tv_sec = fs32_to_cpu(sbi, raw_inode->di_mtime);
inode->i_mtime.tv_nsec = 0;
inode->i_atime.tv_sec = fs32_to_cpu(sbi, raw_inode->di_atime);
inode->i_atime.tv_nsec = 0;
inode->i_ctime.tv_sec = fs32_to_cpu(sbi, raw_inode->di_ctime);
inode->i_ctime.tv_nsec = 0;
/* calc blocks based on 512 byte blocksize */
inode->i_blocks = (inode->i_size + 511) >> 9;
memcpy(&ei->di_block_ptr, &raw_inode->di_block_ptr,
sizeof(raw_inode->di_block_ptr));
ei->di_filelevels = raw_inode->di_filelevels;
if (S_ISREG(inode->i_mode)) {
inode->i_fop = &generic_ro_fops;
inode->i_mapping->a_ops = &qnx6_aops;
} else if (S_ISDIR(inode->i_mode)) {
inode->i_op = &qnx6_dir_inode_operations;
inode->i_fop = &qnx6_dir_operations;
inode->i_mapping->a_ops = &qnx6_aops;
} else if (S_ISLNK(inode->i_mode)) {
inode->i_op = &page_symlink_inode_operations;
inode->i_mapping->a_ops = &qnx6_aops;
} else
init_special_inode(inode, inode->i_mode, 0);
qnx6_put_page(page);
unlock_new_inode(inode);
return inode;
}
static struct kmem_cache *qnx6_inode_cachep;
static struct inode *qnx6_alloc_inode(struct super_block *sb)
{
struct qnx6_inode_info *ei;
ei = kmem_cache_alloc(qnx6_inode_cachep, GFP_KERNEL);
if (!ei)
return NULL;
return &ei->vfs_inode;
}
static void qnx6_i_callback(struct rcu_head *head)
{
struct inode *inode = container_of(head, struct inode, i_rcu);
INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(qnx6_inode_cachep, QNX6_I(inode));
}
static void qnx6_destroy_inode(struct inode *inode)
{
call_rcu(&inode->i_rcu, qnx6_i_callback);
}
static void init_once(void *foo)
{
struct qnx6_inode_info *ei = (struct qnx6_inode_info *) foo;
inode_init_once(&ei->vfs_inode);
}
static int init_inodecache(void)
{
qnx6_inode_cachep = kmem_cache_create("qnx6_inode_cache",
sizeof(struct qnx6_inode_info),
0, (SLAB_RECLAIM_ACCOUNT|
SLAB_MEM_SPREAD),
init_once);
if (!qnx6_inode_cachep)
return -ENOMEM;
return 0;
}
static void destroy_inodecache(void)
{
kmem_cache_destroy(qnx6_inode_cachep);
}
static struct dentry *qnx6_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
return mount_bdev(fs_type, flags, dev_name, data, qnx6_fill_super);
}
static struct file_system_type qnx6_fs_type = {
.owner = THIS_MODULE,
.name = "qnx6",
.mount = qnx6_mount,
.kill_sb = kill_block_super,
.fs_flags = FS_REQUIRES_DEV,
};
static int __init init_qnx6_fs(void)
{
int err;
err = init_inodecache();
if (err)
return err;
err = register_filesystem(&qnx6_fs_type);
if (err) {
destroy_inodecache();
return err;
}
printk(KERN_INFO "QNX6 filesystem 1.0.0 registered.\n");
return 0;
}
static void __exit exit_qnx6_fs(void)
{
unregister_filesystem(&qnx6_fs_type);
destroy_inodecache();
}
module_init(init_qnx6_fs)
module_exit(exit_qnx6_fs)
MODULE_LICENSE("GPL");