- 根目录:
- fs
- hfs
- super.c
/*
* linux/fs/hfs/super.c
*
* Copyright (C) 1995-1997 Paul H. Hargrove
* (C) 2003 Ardis Technologies <roman@ardistech.com>
* This file may be distributed under the terms of the GNU General Public License.
*
* This file contains hfs_read_super(), some of the super_ops and
* init_hfs_fs() and exit_hfs_fs(). The remaining super_ops are in
* inode.c since they deal with inodes.
*
* Based on the minix file system code, (C) 1991, 1992 by Linus Torvalds
*/
#include <linux/module.h>
#include <linux/blkdev.h>
#include <linux/mount.h>
#include <linux/init.h>
#include <linux/nls.h>
#include <linux/parser.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/vfs.h>
#include "hfs_fs.h"
#include "btree.h"
static struct kmem_cache *hfs_inode_cachep;
MODULE_LICENSE("GPL");
static int hfs_sync_fs(struct super_block *sb, int wait)
{
hfs_mdb_commit(sb);
return 0;
}
/*
* hfs_put_super()
*
* This is the put_super() entry in the super_operations structure for
* HFS filesystems. The purpose is to release the resources
* associated with the superblock sb.
*/
static void hfs_put_super(struct super_block *sb)
{
cancel_delayed_work_sync(&HFS_SB(sb)->mdb_work);
hfs_mdb_close(sb);
/* release the MDB's resources */
hfs_mdb_put(sb);
}
static void flush_mdb(struct work_struct *work)
{
struct hfs_sb_info *sbi;
struct super_block *sb;
sbi = container_of(work, struct hfs_sb_info, mdb_work.work);
sb = sbi->sb;
spin_lock(&sbi->work_lock);
sbi->work_queued = 0;
spin_unlock(&sbi->work_lock);
hfs_mdb_commit(sb);
}
void hfs_mark_mdb_dirty(struct super_block *sb)
{
struct hfs_sb_info *sbi = HFS_SB(sb);
unsigned long delay;
if (sb->s_flags & MS_RDONLY)
return;
spin_lock(&sbi->work_lock);
if (!sbi->work_queued) {
delay = msecs_to_jiffies(dirty_writeback_interval * 10);
queue_delayed_work(system_long_wq, &sbi->mdb_work, delay);
sbi->work_queued = 1;
}
spin_unlock(&sbi->work_lock);
}
/*
* hfs_statfs()
*
* This is the statfs() entry in the super_operations structure for
* HFS filesystems. The purpose is to return various data about the
* filesystem.
*
* changed f_files/f_ffree to reflect the fs_ablock/free_ablocks.
*/
static int hfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct super_block *sb = dentry->d_sb;
u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
buf->f_type = HFS_SUPER_MAGIC;
buf->f_bsize = sb->s_blocksize;
buf->f_blocks = (u32)HFS_SB(sb)->fs_ablocks * HFS_SB(sb)->fs_div;
buf->f_bfree = (u32)HFS_SB(sb)->free_ablocks * HFS_SB(sb)->fs_div;
buf->f_bavail = buf->f_bfree;
buf->f_files = HFS_SB(sb)->fs_ablocks;
buf->f_ffree = HFS_SB(sb)->free_ablocks;
buf->f_fsid.val[0] = (u32)id;
buf->f_fsid.val[1] = (u32)(id >> 32);
buf->f_namelen = HFS_NAMELEN;
return 0;
}
static int hfs_remount(struct super_block *sb, int *flags, char *data)
{
*flags |= MS_NODIRATIME;
if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
return 0;
if (!(*flags & MS_RDONLY)) {
if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
pr_warn("filesystem was not cleanly unmounted, running fsck.hfs is recommended. leaving read-only.\n");
sb->s_flags |= MS_RDONLY;
*flags |= MS_RDONLY;
} else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {
pr_warn("filesystem is marked locked, leaving read-only.\n");
sb->s_flags |= MS_RDONLY;
*flags |= MS_RDONLY;
}
}
return 0;
}
static int hfs_show_options(struct seq_file *seq, struct dentry *root)
{
struct hfs_sb_info *sbi = HFS_SB(root->d_sb);
if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f))
seq_printf(seq, ",creator=%.4s", (char *)&sbi->s_creator);
if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
seq_printf(seq, ",type=%.4s", (char *)&sbi->s_type);
seq_printf(seq, ",uid=%u,gid=%u",
from_kuid_munged(&init_user_ns, sbi->s_uid),
from_kgid_munged(&init_user_ns, sbi->s_gid));
if (sbi->s_file_umask != 0133)
seq_printf(seq, ",file_umask=%o", sbi->s_file_umask);
if (sbi->s_dir_umask != 0022)
seq_printf(seq, ",dir_umask=%o", sbi->s_dir_umask);
if (sbi->part >= 0)
seq_printf(seq, ",part=%u", sbi->part);
if (sbi->session >= 0)
seq_printf(seq, ",session=%u", sbi->session);
if (sbi->nls_disk)
seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset);
if (sbi->nls_io)
seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset);
if (sbi->s_quiet)
seq_printf(seq, ",quiet");
return 0;
}
static struct inode *hfs_alloc_inode(struct super_block *sb)
{
struct hfs_inode_info *i;
i = kmem_cache_alloc(hfs_inode_cachep, GFP_KERNEL);
return i ? &i->vfs_inode : NULL;
}
static void hfs_i_callback(struct rcu_head *head)
{
struct inode *inode = container_of(head, struct inode, i_rcu);
kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
}
static void hfs_destroy_inode(struct inode *inode)
{
call_rcu(&inode->i_rcu, hfs_i_callback);
}
static const struct super_operations hfs_super_operations = {
.alloc_inode = hfs_alloc_inode,
.destroy_inode = hfs_destroy_inode,
.write_inode = hfs_write_inode,
.evict_inode = hfs_evict_inode,
.put_super = hfs_put_super,
.sync_fs = hfs_sync_fs,
.statfs = hfs_statfs,
.remount_fs = hfs_remount,
.show_options = hfs_show_options,
};
enum {
opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
opt_part, opt_session, opt_type, opt_creator, opt_quiet,
opt_codepage, opt_iocharset,
opt_err
};
static const match_table_t tokens = {
{ opt_uid, "uid=%u" },
{ opt_gid, "gid=%u" },
{ opt_umask, "umask=%o" },
{ opt_file_umask, "file_umask=%o" },
{ opt_dir_umask, "dir_umask=%o" },
{ opt_part, "part=%u" },
{ opt_session, "session=%u" },
{ opt_type, "type=%s" },
{ opt_creator, "creator=%s" },
{ opt_quiet, "quiet" },
{ opt_codepage, "codepage=%s" },
{ opt_iocharset, "iocharset=%s" },
{ opt_err, NULL }
};
static inline int match_fourchar(substring_t *arg, u32 *result)
{
if (arg->to - arg->from != 4)
return -EINVAL;
memcpy(result, arg->from, 4);
return 0;
}
/*
* parse_options()
*
* adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger
* This function is called by hfs_read_super() to parse the mount options.
*/
static int parse_options(char *options, struct hfs_sb_info *hsb)
{
char *p;
substring_t args[MAX_OPT_ARGS];
int tmp, token;
/* initialize the sb with defaults */
hsb->s_uid = current_uid();
hsb->s_gid = current_gid();
hsb->s_file_umask = 0133;
hsb->s_dir_umask = 0022;
hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f); /* == '????' */
hsb->s_quiet = 0;
hsb->part = -1;
hsb->session = -1;
if (!options)
return 1;
while ((p = strsep(&options, ",")) != NULL) {
if (!*p)
continue;
token = match_token(p, tokens, args);
switch (token) {
case opt_uid:
if (match_int(&args[0], &tmp)) {
pr_err("uid requires an argument\n");
return 0;
}
hsb->s_uid = make_kuid(current_user_ns(), (uid_t)tmp);
if (!uid_valid(hsb->s_uid)) {
pr_err("invalid uid %d\n", tmp);
return 0;
}
break;
case opt_gid:
if (match_int(&args[0], &tmp)) {
pr_err("gid requires an argument\n");
return 0;
}
hsb->s_gid = make_kgid(current_user_ns(), (gid_t)tmp);
if (!gid_valid(hsb->s_gid)) {
pr_err("invalid gid %d\n", tmp);
return 0;
}
break;
case opt_umask:
if (match_octal(&args[0], &tmp)) {
pr_err("umask requires a value\n");
return 0;
}
hsb->s_file_umask = (umode_t)tmp;
hsb->s_dir_umask = (umode_t)tmp;
break;
case opt_file_umask:
if (match_octal(&args[0], &tmp)) {
pr_err("file_umask requires a value\n");
return 0;
}
hsb->s_file_umask = (umode_t)tmp;
break;
case opt_dir_umask:
if (match_octal(&args[0], &tmp)) {
pr_err("dir_umask requires a value\n");
return 0;
}
hsb->s_dir_umask = (umode_t)tmp;
break;
case opt_part:
if (match_int(&args[0], &hsb->part)) {
pr_err("part requires an argument\n");
return 0;
}
break;
case opt_session:
if (match_int(&args[0], &hsb->session)) {
pr_err("session requires an argument\n");
return 0;
}
break;
case opt_type:
if (match_fourchar(&args[0], &hsb->s_type)) {
pr_err("type requires a 4 character value\n");
return 0;
}
break;
case opt_creator:
if (match_fourchar(&args[0], &hsb->s_creator)) {
pr_err("creator requires a 4 character value\n");
return 0;
}
break;
case opt_quiet:
hsb->s_quiet = 1;
break;
case opt_codepage:
if (hsb->nls_disk) {
pr_err("unable to change codepage\n");
return 0;
}
p = match_strdup(&args[0]);
if (p)
hsb->nls_disk = load_nls(p);
if (!hsb->nls_disk) {
pr_err("unable to load codepage \"%s\"\n", p);
kfree(p);
return 0;
}
kfree(p);
break;
case opt_iocharset:
if (hsb->nls_io) {
pr_err("unable to change iocharset\n");
return 0;
}
p = match_strdup(&args[0]);
if (p)
hsb->nls_io = load_nls(p);
if (!hsb->nls_io) {
pr_err("unable to load iocharset \"%s\"\n", p);
kfree(p);
return 0;
}
kfree(p);
break;
default:
return 0;
}
}
if (hsb->nls_disk && !hsb->nls_io) {
hsb->nls_io = load_nls_default();
if (!hsb->nls_io) {
pr_err("unable to load default iocharset\n");
return 0;
}
}
hsb->s_dir_umask &= 0777;
hsb->s_file_umask &= 0577;
return 1;
}
/*
* hfs_read_super()
*
* This is the function that is responsible for mounting an HFS
* filesystem. It performs all the tasks necessary to get enough data
* from the disk to read the root inode. This includes parsing the
* mount options, dealing with Macintosh partitions, reading the
* superblock and the allocation bitmap blocks, calling
* hfs_btree_init() to get the necessary data about the extents and
* catalog B-trees and, finally, reading the root inode into memory.
*/
static int hfs_fill_super(struct super_block *sb, void *data, int silent)
{
struct hfs_sb_info *sbi;
struct hfs_find_data fd;
hfs_cat_rec rec;
struct inode *root_inode;
int res;
sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
if (!sbi)
return -ENOMEM;
sbi->sb = sb;
sb->s_fs_info = sbi;
spin_lock_init(&sbi->work_lock);
INIT_DELAYED_WORK(&sbi->mdb_work, flush_mdb);
res = -EINVAL;
if (!parse_options((char *)data, sbi)) {
pr_err("unable to parse mount options\n");
goto bail;
}
sb->s_op = &hfs_super_operations;
sb->s_flags |= MS_NODIRATIME;
mutex_init(&sbi->bitmap_lock);
res = hfs_mdb_get(sb);
if (res) {
if (!silent)
pr_warn("can't find a HFS filesystem on dev %s\n",
hfs_mdb_name(sb));
res = -EINVAL;
goto bail;
}
/* try to get the root inode */
res = hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
if (res)
goto bail_no_root;
res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
if (!res) {
if (fd.entrylength > sizeof(rec) || fd.entrylength < 0) {
res = -EIO;
goto bail;
}
hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
}
if (res) {
hfs_find_exit(&fd);
goto bail_no_root;
}
res = -EINVAL;
root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
hfs_find_exit(&fd);
if (!root_inode)
goto bail_no_root;
sb->s_d_op = &hfs_dentry_operations;
res = -ENOMEM;
sb->s_root = d_make_root(root_inode);
if (!sb->s_root)
goto bail_no_root;
/* everything's okay */
return 0;
bail_no_root:
pr_err("get root inode failed\n");
bail:
hfs_mdb_put(sb);
return res;
}
static struct dentry *hfs_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
return mount_bdev(fs_type, flags, dev_name, data, hfs_fill_super);
}
static struct file_system_type hfs_fs_type = {
.owner = THIS_MODULE,
.name = "hfs",
.mount = hfs_mount,
.kill_sb = kill_block_super,
.fs_flags = FS_REQUIRES_DEV,
};
MODULE_ALIAS_FS("hfs");
static void hfs_init_once(void *p)
{
struct hfs_inode_info *i = p;
inode_init_once(&i->vfs_inode);
}
static int __init init_hfs_fs(void)
{
int err;
hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
sizeof(struct hfs_inode_info), 0, SLAB_HWCACHE_ALIGN,
hfs_init_once);
if (!hfs_inode_cachep)
return -ENOMEM;
err = register_filesystem(&hfs_fs_type);
if (err)
kmem_cache_destroy(hfs_inode_cachep);
return err;
}
static void __exit exit_hfs_fs(void)
{
unregister_filesystem(&hfs_fs_type);
/*
* Make sure all delayed rcu free inodes are flushed before we
* destroy cache.
*/
rcu_barrier();
kmem_cache_destroy(hfs_inode_cachep);
}
module_init(init_hfs_fs)
module_exit(exit_hfs_fs)