- 根目录:
- fs
- affs
- super.c
/*
* linux/fs/affs/inode.c
*
* (c) 1996 Hans-Joachim Widmaier - Rewritten
*
* (C) 1993 Ray Burr - Modified for Amiga FFS filesystem.
*
* (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem.
*
* (C) 1991 Linus Torvalds - minix filesystem
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/statfs.h>
#include <linux/parser.h>
#include <linux/magic.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/writeback.h>
#include <linux/blkdev.h>
#include "affs.h"
static int affs_statfs(struct dentry *dentry, struct kstatfs *buf);
static int affs_remount (struct super_block *sb, int *flags, char *data);
static void
affs_commit_super(struct super_block *sb, int wait)
{
struct affs_sb_info *sbi = AFFS_SB(sb);
struct buffer_head *bh = sbi->s_root_bh;
struct affs_root_tail *tail = AFFS_ROOT_TAIL(sb, bh);
lock_buffer(bh);
secs_to_datestamp(get_seconds(), &tail->disk_change);
affs_fix_checksum(sb, bh);
unlock_buffer(bh);
mark_buffer_dirty(bh);
if (wait)
sync_dirty_buffer(bh);
}
static void
affs_put_super(struct super_block *sb)
{
struct affs_sb_info *sbi = AFFS_SB(sb);
pr_debug("%s()\n", __func__);
cancel_delayed_work_sync(&sbi->sb_work);
}
static int
affs_sync_fs(struct super_block *sb, int wait)
{
affs_commit_super(sb, wait);
return 0;
}
static void flush_superblock(struct work_struct *work)
{
struct affs_sb_info *sbi;
struct super_block *sb;
sbi = container_of(work, struct affs_sb_info, sb_work.work);
sb = sbi->sb;
spin_lock(&sbi->work_lock);
sbi->work_queued = 0;
spin_unlock(&sbi->work_lock);
affs_commit_super(sb, 1);
}
void affs_mark_sb_dirty(struct super_block *sb)
{
struct affs_sb_info *sbi = AFFS_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->sb_work, delay);
sbi->work_queued = 1;
}
spin_unlock(&sbi->work_lock);
}
static struct kmem_cache * affs_inode_cachep;
static struct inode *affs_alloc_inode(struct super_block *sb)
{
struct affs_inode_info *i;
i = kmem_cache_alloc(affs_inode_cachep, GFP_KERNEL);
if (!i)
return NULL;
i->vfs_inode.i_version = 1;
i->i_lc = NULL;
i->i_ext_bh = NULL;
i->i_pa_cnt = 0;
return &i->vfs_inode;
}
static void affs_i_callback(struct rcu_head *head)
{
struct inode *inode = container_of(head, struct inode, i_rcu);
kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
}
static void affs_destroy_inode(struct inode *inode)
{
call_rcu(&inode->i_rcu, affs_i_callback);
}
static void init_once(void *foo)
{
struct affs_inode_info *ei = (struct affs_inode_info *) foo;
sema_init(&ei->i_link_lock, 1);
sema_init(&ei->i_ext_lock, 1);
inode_init_once(&ei->vfs_inode);
}
static int __init init_inodecache(void)
{
affs_inode_cachep = kmem_cache_create("affs_inode_cache",
sizeof(struct affs_inode_info),
0, (SLAB_RECLAIM_ACCOUNT|
SLAB_MEM_SPREAD),
init_once);
if (affs_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(affs_inode_cachep);
}
static const struct super_operations affs_sops = {
.alloc_inode = affs_alloc_inode,
.destroy_inode = affs_destroy_inode,
.write_inode = affs_write_inode,
.evict_inode = affs_evict_inode,
.put_super = affs_put_super,
.sync_fs = affs_sync_fs,
.statfs = affs_statfs,
.remount_fs = affs_remount,
.show_options = generic_show_options,
};
enum {
Opt_bs, Opt_mode, Opt_mufs, Opt_notruncate, Opt_prefix, Opt_protect,
Opt_reserved, Opt_root, Opt_setgid, Opt_setuid,
Opt_verbose, Opt_volume, Opt_ignore, Opt_err,
};
static const match_table_t tokens = {
{Opt_bs, "bs=%u"},
{Opt_mode, "mode=%o"},
{Opt_mufs, "mufs"},
{Opt_notruncate, "nofilenametruncate"},
{Opt_prefix, "prefix=%s"},
{Opt_protect, "protect"},
{Opt_reserved, "reserved=%u"},
{Opt_root, "root=%u"},
{Opt_setgid, "setgid=%u"},
{Opt_setuid, "setuid=%u"},
{Opt_verbose, "verbose"},
{Opt_volume, "volume=%s"},
{Opt_ignore, "grpquota"},
{Opt_ignore, "noquota"},
{Opt_ignore, "quota"},
{Opt_ignore, "usrquota"},
{Opt_err, NULL},
};
static int
parse_options(char *options, kuid_t *uid, kgid_t *gid, int *mode, int *reserved, s32 *root,
int *blocksize, char **prefix, char *volume, unsigned long *mount_opts)
{
char *p;
substring_t args[MAX_OPT_ARGS];
/* Fill in defaults */
*uid = current_uid();
*gid = current_gid();
*reserved = 2;
*root = -1;
*blocksize = -1;
volume[0] = ':';
volume[1] = 0;
*mount_opts = 0;
if (!options)
return 1;
while ((p = strsep(&options, ",")) != NULL) {
int token, n, option;
if (!*p)
continue;
token = match_token(p, tokens, args);
switch (token) {
case Opt_bs:
if (match_int(&args[0], &n))
return 0;
if (n != 512 && n != 1024 && n != 2048
&& n != 4096) {
pr_warn("Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
return 0;
}
*blocksize = n;
break;
case Opt_mode:
if (match_octal(&args[0], &option))
return 0;
*mode = option & 0777;
affs_set_opt(*mount_opts, SF_SETMODE);
break;
case Opt_mufs:
affs_set_opt(*mount_opts, SF_MUFS);
break;
case Opt_notruncate:
affs_set_opt(*mount_opts, SF_NO_TRUNCATE);
break;
case Opt_prefix:
*prefix = match_strdup(&args[0]);
if (!*prefix)
return 0;
affs_set_opt(*mount_opts, SF_PREFIX);
break;
case Opt_protect:
affs_set_opt(*mount_opts, SF_IMMUTABLE);
break;
case Opt_reserved:
if (match_int(&args[0], reserved))
return 0;
break;
case Opt_root:
if (match_int(&args[0], root))
return 0;
break;
case Opt_setgid:
if (match_int(&args[0], &option))
return 0;
*gid = make_kgid(current_user_ns(), option);
if (!gid_valid(*gid))
return 0;
affs_set_opt(*mount_opts, SF_SETGID);
break;
case Opt_setuid:
if (match_int(&args[0], &option))
return 0;
*uid = make_kuid(current_user_ns(), option);
if (!uid_valid(*uid))
return 0;
affs_set_opt(*mount_opts, SF_SETUID);
break;
case Opt_verbose:
affs_set_opt(*mount_opts, SF_VERBOSE);
break;
case Opt_volume: {
char *vol = match_strdup(&args[0]);
if (!vol)
return 0;
strlcpy(volume, vol, 32);
kfree(vol);
break;
}
case Opt_ignore:
/* Silently ignore the quota options */
break;
default:
pr_warn("Unrecognized mount option \"%s\" or missing value\n",
p);
return 0;
}
}
return 1;
}
/* This function definitely needs to be split up. Some fine day I'll
* hopefully have the guts to do so. Until then: sorry for the mess.
*/
static int affs_fill_super(struct super_block *sb, void *data, int silent)
{
struct affs_sb_info *sbi;
struct buffer_head *root_bh = NULL;
struct buffer_head *boot_bh;
struct inode *root_inode = NULL;
s32 root_block;
int size, blocksize;
u32 chksum;
int num_bm;
int i, j;
kuid_t uid;
kgid_t gid;
int reserved;
unsigned long mount_flags;
int tmp_flags; /* fix remount prototype... */
u8 sig[4];
int ret;
save_mount_options(sb, data);
pr_debug("read_super(%s)\n", data ? (const char *)data : "no options");
sb->s_magic = AFFS_SUPER_MAGIC;
sb->s_op = &affs_sops;
sb->s_flags |= MS_NODIRATIME;
sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
if (!sbi)
return -ENOMEM;
sb->s_fs_info = sbi;
sbi->sb = sb;
mutex_init(&sbi->s_bmlock);
spin_lock_init(&sbi->symlink_lock);
spin_lock_init(&sbi->work_lock);
INIT_DELAYED_WORK(&sbi->sb_work, flush_superblock);
if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
&blocksize,&sbi->s_prefix,
sbi->s_volume, &mount_flags)) {
pr_err("Error parsing options\n");
return -EINVAL;
}
/* N.B. after this point s_prefix must be released */
sbi->s_flags = mount_flags;
sbi->s_mode = i;
sbi->s_uid = uid;
sbi->s_gid = gid;
sbi->s_reserved= reserved;
/* Get the size of the device in 512-byte blocks.
* If we later see that the partition uses bigger
* blocks, we will have to change it.
*/
size = i_size_read(sb->s_bdev->bd_inode) >> 9;
pr_debug("initial blocksize=%d, #blocks=%d\n", 512, size);
affs_set_blocksize(sb, PAGE_SIZE);
/* Try to find root block. Its location depends on the block size. */
i = bdev_logical_block_size(sb->s_bdev);
j = PAGE_SIZE;
if (blocksize > 0) {
i = j = blocksize;
size = size / (blocksize / 512);
}
for (blocksize = i; blocksize <= j; blocksize <<= 1, size >>= 1) {
sbi->s_root_block = root_block;
if (root_block < 0)
sbi->s_root_block = (reserved + size - 1) / 2;
pr_debug("setting blocksize to %d\n", blocksize);
affs_set_blocksize(sb, blocksize);
sbi->s_partition_size = size;
/* The root block location that was calculated above is not
* correct if the partition size is an odd number of 512-
* byte blocks, which will be rounded down to a number of
* 1024-byte blocks, and if there were an even number of
* reserved blocks. Ideally, all partition checkers should
* report the real number of blocks of the real blocksize,
* but since this just cannot be done, we have to try to
* find the root block anyways. In the above case, it is one
* block behind the calculated one. So we check this one, too.
*/
for (num_bm = 0; num_bm < 2; num_bm++) {
pr_debug("Dev %s, trying root=%u, bs=%d, "
"size=%d, reserved=%d\n",
sb->s_id,
sbi->s_root_block + num_bm,
blocksize, size, reserved);
root_bh = affs_bread(sb, sbi->s_root_block + num_bm);
if (!root_bh)
continue;
if (!affs_checksum_block(sb, root_bh) &&
be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
sbi->s_hashsize = blocksize / 4 - 56;
sbi->s_root_block += num_bm;
goto got_root;
}
affs_brelse(root_bh);
root_bh = NULL;
}
}
if (!silent)
pr_err("No valid root block on device %s\n", sb->s_id);
return -EINVAL;
/* N.B. after this point bh must be released */
got_root:
/* Keep super block in cache */
sbi->s_root_bh = root_bh;
root_block = sbi->s_root_block;
/* Find out which kind of FS we have */
boot_bh = sb_bread(sb, 0);
if (!boot_bh) {
pr_err("Cannot read boot block\n");
return -EINVAL;
}
memcpy(sig, boot_bh->b_data, 4);
brelse(boot_bh);
chksum = be32_to_cpu(*(__be32 *)sig);
/* Dircache filesystems are compatible with non-dircache ones
* when reading. As long as they aren't supported, writing is
* not recommended.
*/
if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
|| chksum == MUFS_DCOFS) && !(sb->s_flags & MS_RDONLY)) {
pr_notice("Dircache FS - mounting %s read only\n", sb->s_id);
sb->s_flags |= MS_RDONLY;
}
switch (chksum) {
case MUFS_FS:
case MUFS_INTLFFS:
case MUFS_DCFFS:
affs_set_opt(sbi->s_flags, SF_MUFS);
/* fall thru */
case FS_INTLFFS:
case FS_DCFFS:
affs_set_opt(sbi->s_flags, SF_INTL);
break;
case MUFS_FFS:
affs_set_opt(sbi->s_flags, SF_MUFS);
break;
case FS_FFS:
break;
case MUFS_OFS:
affs_set_opt(sbi->s_flags, SF_MUFS);
/* fall thru */
case FS_OFS:
affs_set_opt(sbi->s_flags, SF_OFS);
sb->s_flags |= MS_NOEXEC;
break;
case MUFS_DCOFS:
case MUFS_INTLOFS:
affs_set_opt(sbi->s_flags, SF_MUFS);
case FS_DCOFS:
case FS_INTLOFS:
affs_set_opt(sbi->s_flags, SF_INTL);
affs_set_opt(sbi->s_flags, SF_OFS);
sb->s_flags |= MS_NOEXEC;
break;
default:
pr_err("Unknown filesystem on device %s: %08X\n",
sb->s_id, chksum);
return -EINVAL;
}
if (affs_test_opt(mount_flags, SF_VERBOSE)) {
u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0];
pr_notice("Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n",
len > 31 ? 31 : len,
AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
sig, sig[3] + '0', blocksize);
}
sb->s_flags |= MS_NODEV | MS_NOSUID;
sbi->s_data_blksize = sb->s_blocksize;
if (affs_test_opt(sbi->s_flags, SF_OFS))
sbi->s_data_blksize -= 24;
tmp_flags = sb->s_flags;
ret = affs_init_bitmap(sb, &tmp_flags);
if (ret)
return ret;
sb->s_flags = tmp_flags;
/* set up enough so that it can read an inode */
root_inode = affs_iget(sb, root_block);
if (IS_ERR(root_inode))
return PTR_ERR(root_inode);
if (affs_test_opt(AFFS_SB(sb)->s_flags, SF_INTL))
sb->s_d_op = &affs_intl_dentry_operations;
else
sb->s_d_op = &affs_dentry_operations;
sb->s_root = d_make_root(root_inode);
if (!sb->s_root) {
pr_err("AFFS: Get root inode failed\n");
return -ENOMEM;
}
pr_debug("s_flags=%lX\n", sb->s_flags);
return 0;
}
static int
affs_remount(struct super_block *sb, int *flags, char *data)
{
struct affs_sb_info *sbi = AFFS_SB(sb);
int blocksize;
kuid_t uid;
kgid_t gid;
int mode;
int reserved;
int root_block;
unsigned long mount_flags;
int res = 0;
char *new_opts;
char volume[32];
char *prefix = NULL;
new_opts = kstrdup(data, GFP_KERNEL);
if (!new_opts)
return -ENOMEM;
pr_debug("%s(flags=0x%x,opts=\"%s\")\n", __func__, *flags, data);
sync_filesystem(sb);
*flags |= MS_NODIRATIME;
memcpy(volume, sbi->s_volume, 32);
if (!parse_options(data, &uid, &gid, &mode, &reserved, &root_block,
&blocksize, &prefix, volume,
&mount_flags)) {
kfree(prefix);
kfree(new_opts);
return -EINVAL;
}
flush_delayed_work(&sbi->sb_work);
replace_mount_options(sb, new_opts);
sbi->s_flags = mount_flags;
sbi->s_mode = mode;
sbi->s_uid = uid;
sbi->s_gid = gid;
/* protect against readers */
spin_lock(&sbi->symlink_lock);
if (prefix) {
kfree(sbi->s_prefix);
sbi->s_prefix = prefix;
}
memcpy(sbi->s_volume, volume, 32);
spin_unlock(&sbi->symlink_lock);
if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
return 0;
if (*flags & MS_RDONLY)
affs_free_bitmap(sb);
else
res = affs_init_bitmap(sb, flags);
return res;
}
static int
affs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct super_block *sb = dentry->d_sb;
int free;
u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
pr_debug("%s() partsize=%d, reserved=%d\n",
__func__, AFFS_SB(sb)->s_partition_size,
AFFS_SB(sb)->s_reserved);
free = affs_count_free_blocks(sb);
buf->f_type = AFFS_SUPER_MAGIC;
buf->f_bsize = sb->s_blocksize;
buf->f_blocks = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;
buf->f_bfree = free;
buf->f_bavail = free;
buf->f_fsid.val[0] = (u32)id;
buf->f_fsid.val[1] = (u32)(id >> 32);
buf->f_namelen = AFFSNAMEMAX;
return 0;
}
static struct dentry *affs_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
return mount_bdev(fs_type, flags, dev_name, data, affs_fill_super);
}
static void affs_kill_sb(struct super_block *sb)
{
struct affs_sb_info *sbi = AFFS_SB(sb);
kill_block_super(sb);
if (sbi) {
affs_free_bitmap(sb);
affs_brelse(sbi->s_root_bh);
kfree(sbi->s_prefix);
mutex_destroy(&sbi->s_bmlock);
kfree(sbi);
}
}
static struct file_system_type affs_fs_type = {
.owner = THIS_MODULE,
.name = "affs",
.mount = affs_mount,
.kill_sb = affs_kill_sb,
.fs_flags = FS_REQUIRES_DEV,
};
MODULE_ALIAS_FS("affs");
static int __init init_affs_fs(void)
{
int err = init_inodecache();
if (err)
goto out1;
err = register_filesystem(&affs_fs_type);
if (err)
goto out;
return 0;
out:
destroy_inodecache();
out1:
return err;
}
static void __exit exit_affs_fs(void)
{
unregister_filesystem(&affs_fs_type);
destroy_inodecache();
}
MODULE_DESCRIPTION("Amiga filesystem support for Linux");
MODULE_LICENSE("GPL");
module_init(init_affs_fs)
module_exit(exit_affs_fs)