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mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-27 14:43:58 +08:00
linux-next/fs/hpfs/super.c
Arnd Bergmann 9a311b96c3 hpfs: remove the BKL
This removes the BKL in hpfs in a rather awful
way, by making the code only work on uniprocessor
systems without kernel preemption, as suggested
by Andi Kleen.

The HPFS code probably has close to zero remaining
users on current kernels, all archeological uses of
the file system can probably be done with the significant
restrictions.

The hpfs_lock/hpfs_unlock functions are left in the
code, sincen Mikulas has indicated that he is still
interested in fixing it in a better way.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Andi Kleen <ak@linux.intel.com>
Cc: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Cc: linux-fsdevel@vger.kernel.org
2011-03-02 22:27:36 +01:00

729 lines
19 KiB
C

/*
* linux/fs/hpfs/super.c
*
* Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
*
* mounting, unmounting, error handling
*/
#include "hpfs_fn.h"
#include <linux/module.h>
#include <linux/parser.h>
#include <linux/init.h>
#include <linux/statfs.h>
#include <linux/magic.h>
#include <linux/sched.h>
#include <linux/bitmap.h>
#include <linux/slab.h>
/* Mark the filesystem dirty, so that chkdsk checks it when os/2 booted */
static void mark_dirty(struct super_block *s)
{
if (hpfs_sb(s)->sb_chkdsk && !(s->s_flags & MS_RDONLY)) {
struct buffer_head *bh;
struct hpfs_spare_block *sb;
if ((sb = hpfs_map_sector(s, 17, &bh, 0))) {
sb->dirty = 1;
sb->old_wrote = 0;
mark_buffer_dirty(bh);
brelse(bh);
}
}
}
/* Mark the filesystem clean (mark it dirty for chkdsk if chkdsk==2 or if there
were errors) */
static void unmark_dirty(struct super_block *s)
{
struct buffer_head *bh;
struct hpfs_spare_block *sb;
if (s->s_flags & MS_RDONLY) return;
if ((sb = hpfs_map_sector(s, 17, &bh, 0))) {
sb->dirty = hpfs_sb(s)->sb_chkdsk > 1 - hpfs_sb(s)->sb_was_error;
sb->old_wrote = hpfs_sb(s)->sb_chkdsk >= 2 && !hpfs_sb(s)->sb_was_error;
mark_buffer_dirty(bh);
brelse(bh);
}
}
/* Filesystem error... */
static char err_buf[1024];
void hpfs_error(struct super_block *s, const char *fmt, ...)
{
va_list args;
va_start(args, fmt);
vsnprintf(err_buf, sizeof(err_buf), fmt, args);
va_end(args);
printk("HPFS: filesystem error: %s", err_buf);
if (!hpfs_sb(s)->sb_was_error) {
if (hpfs_sb(s)->sb_err == 2) {
printk("; crashing the system because you wanted it\n");
mark_dirty(s);
panic("HPFS panic");
} else if (hpfs_sb(s)->sb_err == 1) {
if (s->s_flags & MS_RDONLY) printk("; already mounted read-only\n");
else {
printk("; remounting read-only\n");
mark_dirty(s);
s->s_flags |= MS_RDONLY;
}
} else if (s->s_flags & MS_RDONLY) printk("; going on - but anything won't be destroyed because it's read-only\n");
else printk("; corrupted filesystem mounted read/write - your computer will explode within 20 seconds ... but you wanted it so!\n");
} else printk("\n");
hpfs_sb(s)->sb_was_error = 1;
}
/*
* A little trick to detect cycles in many hpfs structures and don't let the
* kernel crash on corrupted filesystem. When first called, set c2 to 0.
*
* BTW. chkdsk doesn't detect cycles correctly. When I had 2 lost directories
* nested each in other, chkdsk locked up happilly.
*/
int hpfs_stop_cycles(struct super_block *s, int key, int *c1, int *c2,
char *msg)
{
if (*c2 && *c1 == key) {
hpfs_error(s, "cycle detected on key %08x in %s", key, msg);
return 1;
}
(*c2)++;
if (!((*c2 - 1) & *c2)) *c1 = key;
return 0;
}
static void hpfs_put_super(struct super_block *s)
{
struct hpfs_sb_info *sbi = hpfs_sb(s);
kfree(sbi->sb_cp_table);
kfree(sbi->sb_bmp_dir);
unmark_dirty(s);
s->s_fs_info = NULL;
kfree(sbi);
}
unsigned hpfs_count_one_bitmap(struct super_block *s, secno secno)
{
struct quad_buffer_head qbh;
unsigned long *bits;
unsigned count;
bits = hpfs_map_4sectors(s, secno, &qbh, 4);
if (!bits)
return 0;
count = bitmap_weight(bits, 2048 * BITS_PER_BYTE);
hpfs_brelse4(&qbh);
return count;
}
static unsigned count_bitmaps(struct super_block *s)
{
unsigned n, count, n_bands;
n_bands = (hpfs_sb(s)->sb_fs_size + 0x3fff) >> 14;
count = 0;
for (n = 0; n < n_bands; n++)
count += hpfs_count_one_bitmap(s, hpfs_sb(s)->sb_bmp_dir[n]);
return count;
}
static int hpfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct super_block *s = dentry->d_sb;
struct hpfs_sb_info *sbi = hpfs_sb(s);
u64 id = huge_encode_dev(s->s_bdev->bd_dev);
hpfs_lock(s);
/*if (sbi->sb_n_free == -1) {*/
sbi->sb_n_free = count_bitmaps(s);
sbi->sb_n_free_dnodes = hpfs_count_one_bitmap(s, sbi->sb_dmap);
/*}*/
buf->f_type = s->s_magic;
buf->f_bsize = 512;
buf->f_blocks = sbi->sb_fs_size;
buf->f_bfree = sbi->sb_n_free;
buf->f_bavail = sbi->sb_n_free;
buf->f_files = sbi->sb_dirband_size / 4;
buf->f_ffree = sbi->sb_n_free_dnodes;
buf->f_fsid.val[0] = (u32)id;
buf->f_fsid.val[1] = (u32)(id >> 32);
buf->f_namelen = 254;
hpfs_unlock(s);
return 0;
}
static struct kmem_cache * hpfs_inode_cachep;
static struct inode *hpfs_alloc_inode(struct super_block *sb)
{
struct hpfs_inode_info *ei;
ei = (struct hpfs_inode_info *)kmem_cache_alloc(hpfs_inode_cachep, GFP_NOFS);
if (!ei)
return NULL;
ei->vfs_inode.i_version = 1;
return &ei->vfs_inode;
}
static void hpfs_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(hpfs_inode_cachep, hpfs_i(inode));
}
static void hpfs_destroy_inode(struct inode *inode)
{
call_rcu(&inode->i_rcu, hpfs_i_callback);
}
static void init_once(void *foo)
{
struct hpfs_inode_info *ei = (struct hpfs_inode_info *) foo;
mutex_init(&ei->i_mutex);
mutex_init(&ei->i_parent_mutex);
inode_init_once(&ei->vfs_inode);
}
static int init_inodecache(void)
{
hpfs_inode_cachep = kmem_cache_create("hpfs_inode_cache",
sizeof(struct hpfs_inode_info),
0, (SLAB_RECLAIM_ACCOUNT|
SLAB_MEM_SPREAD),
init_once);
if (hpfs_inode_cachep == NULL)
return -ENOMEM;
return 0;
}
static void destroy_inodecache(void)
{
kmem_cache_destroy(hpfs_inode_cachep);
}
/*
* A tiny parser for option strings, stolen from dosfs.
* Stolen again from read-only hpfs.
* And updated for table-driven option parsing.
*/
enum {
Opt_help, Opt_uid, Opt_gid, Opt_umask, Opt_case_lower, Opt_case_asis,
Opt_conv_binary, Opt_conv_text, Opt_conv_auto,
Opt_check_none, Opt_check_normal, Opt_check_strict,
Opt_err_cont, Opt_err_ro, Opt_err_panic,
Opt_eas_no, Opt_eas_ro, Opt_eas_rw,
Opt_chkdsk_no, Opt_chkdsk_errors, Opt_chkdsk_always,
Opt_timeshift, Opt_err,
};
static const match_table_t tokens = {
{Opt_help, "help"},
{Opt_uid, "uid=%u"},
{Opt_gid, "gid=%u"},
{Opt_umask, "umask=%o"},
{Opt_case_lower, "case=lower"},
{Opt_case_asis, "case=asis"},
{Opt_conv_binary, "conv=binary"},
{Opt_conv_text, "conv=text"},
{Opt_conv_auto, "conv=auto"},
{Opt_check_none, "check=none"},
{Opt_check_normal, "check=normal"},
{Opt_check_strict, "check=strict"},
{Opt_err_cont, "errors=continue"},
{Opt_err_ro, "errors=remount-ro"},
{Opt_err_panic, "errors=panic"},
{Opt_eas_no, "eas=no"},
{Opt_eas_ro, "eas=ro"},
{Opt_eas_rw, "eas=rw"},
{Opt_chkdsk_no, "chkdsk=no"},
{Opt_chkdsk_errors, "chkdsk=errors"},
{Opt_chkdsk_always, "chkdsk=always"},
{Opt_timeshift, "timeshift=%d"},
{Opt_err, NULL},
};
static int parse_opts(char *opts, uid_t *uid, gid_t *gid, umode_t *umask,
int *lowercase, int *conv, int *eas, int *chk, int *errs,
int *chkdsk, int *timeshift)
{
char *p;
int option;
if (!opts)
return 1;
/*printk("Parsing opts: '%s'\n",opts);*/
while ((p = strsep(&opts, ",")) != NULL) {
substring_t args[MAX_OPT_ARGS];
int token;
if (!*p)
continue;
token = match_token(p, tokens, args);
switch (token) {
case Opt_help:
return 2;
case Opt_uid:
if (match_int(args, &option))
return 0;
*uid = option;
break;
case Opt_gid:
if (match_int(args, &option))
return 0;
*gid = option;
break;
case Opt_umask:
if (match_octal(args, &option))
return 0;
*umask = option;
break;
case Opt_case_lower:
*lowercase = 1;
break;
case Opt_case_asis:
*lowercase = 0;
break;
case Opt_conv_binary:
*conv = CONV_BINARY;
break;
case Opt_conv_text:
*conv = CONV_TEXT;
break;
case Opt_conv_auto:
*conv = CONV_AUTO;
break;
case Opt_check_none:
*chk = 0;
break;
case Opt_check_normal:
*chk = 1;
break;
case Opt_check_strict:
*chk = 2;
break;
case Opt_err_cont:
*errs = 0;
break;
case Opt_err_ro:
*errs = 1;
break;
case Opt_err_panic:
*errs = 2;
break;
case Opt_eas_no:
*eas = 0;
break;
case Opt_eas_ro:
*eas = 1;
break;
case Opt_eas_rw:
*eas = 2;
break;
case Opt_chkdsk_no:
*chkdsk = 0;
break;
case Opt_chkdsk_errors:
*chkdsk = 1;
break;
case Opt_chkdsk_always:
*chkdsk = 2;
break;
case Opt_timeshift:
{
int m = 1;
char *rhs = args[0].from;
if (!rhs || !*rhs)
return 0;
if (*rhs == '-') m = -1;
if (*rhs == '+' || *rhs == '-') rhs++;
*timeshift = simple_strtoul(rhs, &rhs, 0) * m;
if (*rhs)
return 0;
break;
}
default:
return 0;
}
}
return 1;
}
static inline void hpfs_help(void)
{
printk("\n\
HPFS filesystem options:\n\
help do not mount and display this text\n\
uid=xxx set uid of files that don't have uid specified in eas\n\
gid=xxx set gid of files that don't have gid specified in eas\n\
umask=xxx set mode of files that don't have mode specified in eas\n\
case=lower lowercase all files\n\
case=asis do not lowercase files (default)\n\
conv=binary do not convert CR/LF -> LF (default)\n\
conv=auto convert only files with known text extensions\n\
conv=text convert all files\n\
check=none no fs checks - kernel may crash on corrupted filesystem\n\
check=normal do some checks - it should not crash (default)\n\
check=strict do extra time-consuming checks, used for debugging\n\
errors=continue continue on errors\n\
errors=remount-ro remount read-only if errors found (default)\n\
errors=panic panic on errors\n\
chkdsk=no do not mark fs for chkdsking even if there were errors\n\
chkdsk=errors mark fs dirty if errors found (default)\n\
chkdsk=always always mark fs dirty - used for debugging\n\
eas=no ignore extended attributes\n\
eas=ro read but do not write extended attributes\n\
eas=rw r/w eas => enables chmod, chown, mknod, ln -s (default)\n\
timeshift=nnn add nnn seconds to file times\n\
\n");
}
static int hpfs_remount_fs(struct super_block *s, int *flags, char *data)
{
uid_t uid;
gid_t gid;
umode_t umask;
int lowercase, conv, eas, chk, errs, chkdsk, timeshift;
int o;
struct hpfs_sb_info *sbi = hpfs_sb(s);
char *new_opts = kstrdup(data, GFP_KERNEL);
*flags |= MS_NOATIME;
hpfs_lock(s);
lock_super(s);
uid = sbi->sb_uid; gid = sbi->sb_gid;
umask = 0777 & ~sbi->sb_mode;
lowercase = sbi->sb_lowercase; conv = sbi->sb_conv;
eas = sbi->sb_eas; chk = sbi->sb_chk; chkdsk = sbi->sb_chkdsk;
errs = sbi->sb_err; timeshift = sbi->sb_timeshift;
if (!(o = parse_opts(data, &uid, &gid, &umask, &lowercase, &conv,
&eas, &chk, &errs, &chkdsk, &timeshift))) {
printk("HPFS: bad mount options.\n");
goto out_err;
}
if (o == 2) {
hpfs_help();
goto out_err;
}
if (timeshift != sbi->sb_timeshift) {
printk("HPFS: timeshift can't be changed using remount.\n");
goto out_err;
}
unmark_dirty(s);
sbi->sb_uid = uid; sbi->sb_gid = gid;
sbi->sb_mode = 0777 & ~umask;
sbi->sb_lowercase = lowercase; sbi->sb_conv = conv;
sbi->sb_eas = eas; sbi->sb_chk = chk; sbi->sb_chkdsk = chkdsk;
sbi->sb_err = errs; sbi->sb_timeshift = timeshift;
if (!(*flags & MS_RDONLY)) mark_dirty(s);
replace_mount_options(s, new_opts);
unlock_super(s);
hpfs_unlock(s);
return 0;
out_err:
unlock_super(s);
hpfs_unlock(s);
kfree(new_opts);
return -EINVAL;
}
/* Super operations */
static const struct super_operations hpfs_sops =
{
.alloc_inode = hpfs_alloc_inode,
.destroy_inode = hpfs_destroy_inode,
.evict_inode = hpfs_evict_inode,
.put_super = hpfs_put_super,
.statfs = hpfs_statfs,
.remount_fs = hpfs_remount_fs,
.show_options = generic_show_options,
};
static int hpfs_fill_super(struct super_block *s, void *options, int silent)
{
struct buffer_head *bh0, *bh1, *bh2;
struct hpfs_boot_block *bootblock;
struct hpfs_super_block *superblock;
struct hpfs_spare_block *spareblock;
struct hpfs_sb_info *sbi;
struct inode *root;
uid_t uid;
gid_t gid;
umode_t umask;
int lowercase, conv, eas, chk, errs, chkdsk, timeshift;
dnode_secno root_dno;
struct hpfs_dirent *de = NULL;
struct quad_buffer_head qbh;
int o;
if (num_possible_cpus() > 1) {
printk(KERN_ERR "HPFS is not SMP safe\n");
return -EINVAL;
}
save_mount_options(s, options);
sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
if (!sbi) {
return -ENOMEM;
}
s->s_fs_info = sbi;
sbi->sb_bmp_dir = NULL;
sbi->sb_cp_table = NULL;
mutex_init(&sbi->hpfs_creation_de);
uid = current_uid();
gid = current_gid();
umask = current_umask();
lowercase = 0;
conv = CONV_BINARY;
eas = 2;
chk = 1;
errs = 1;
chkdsk = 1;
timeshift = 0;
if (!(o = parse_opts(options, &uid, &gid, &umask, &lowercase, &conv,
&eas, &chk, &errs, &chkdsk, &timeshift))) {
printk("HPFS: bad mount options.\n");
goto bail0;
}
if (o==2) {
hpfs_help();
goto bail0;
}
/*sbi->sb_mounting = 1;*/
sb_set_blocksize(s, 512);
sbi->sb_fs_size = -1;
if (!(bootblock = hpfs_map_sector(s, 0, &bh0, 0))) goto bail1;
if (!(superblock = hpfs_map_sector(s, 16, &bh1, 1))) goto bail2;
if (!(spareblock = hpfs_map_sector(s, 17, &bh2, 0))) goto bail3;
/* Check magics */
if (/*bootblock->magic != BB_MAGIC
||*/ superblock->magic != SB_MAGIC
|| spareblock->magic != SP_MAGIC) {
if (!silent) printk("HPFS: Bad magic ... probably not HPFS\n");
goto bail4;
}
/* Check version */
if (!(s->s_flags & MS_RDONLY) &&
superblock->funcversion != 2 && superblock->funcversion != 3) {
printk("HPFS: Bad version %d,%d. Mount readonly to go around\n",
(int)superblock->version, (int)superblock->funcversion);
printk("HPFS: please try recent version of HPFS driver at http://artax.karlin.mff.cuni.cz/~mikulas/vyplody/hpfs/index-e.cgi and if it still can't understand this format, contact author - mikulas@artax.karlin.mff.cuni.cz\n");
goto bail4;
}
s->s_flags |= MS_NOATIME;
/* Fill superblock stuff */
s->s_magic = HPFS_SUPER_MAGIC;
s->s_op = &hpfs_sops;
s->s_d_op = &hpfs_dentry_operations;
sbi->sb_root = superblock->root;
sbi->sb_fs_size = superblock->n_sectors;
sbi->sb_bitmaps = superblock->bitmaps;
sbi->sb_dirband_start = superblock->dir_band_start;
sbi->sb_dirband_size = superblock->n_dir_band;
sbi->sb_dmap = superblock->dir_band_bitmap;
sbi->sb_uid = uid;
sbi->sb_gid = gid;
sbi->sb_mode = 0777 & ~umask;
sbi->sb_n_free = -1;
sbi->sb_n_free_dnodes = -1;
sbi->sb_lowercase = lowercase;
sbi->sb_conv = conv;
sbi->sb_eas = eas;
sbi->sb_chk = chk;
sbi->sb_chkdsk = chkdsk;
sbi->sb_err = errs;
sbi->sb_timeshift = timeshift;
sbi->sb_was_error = 0;
sbi->sb_cp_table = NULL;
sbi->sb_c_bitmap = -1;
sbi->sb_max_fwd_alloc = 0xffffff;
/* Load bitmap directory */
if (!(sbi->sb_bmp_dir = hpfs_load_bitmap_directory(s, superblock->bitmaps)))
goto bail4;
/* Check for general fs errors*/
if (spareblock->dirty && !spareblock->old_wrote) {
if (errs == 2) {
printk("HPFS: Improperly stopped, not mounted\n");
goto bail4;
}
hpfs_error(s, "improperly stopped");
}
if (!(s->s_flags & MS_RDONLY)) {
spareblock->dirty = 1;
spareblock->old_wrote = 0;
mark_buffer_dirty(bh2);
}
if (spareblock->hotfixes_used || spareblock->n_spares_used) {
if (errs >= 2) {
printk("HPFS: Hotfixes not supported here, try chkdsk\n");
mark_dirty(s);
goto bail4;
}
hpfs_error(s, "hotfixes not supported here, try chkdsk");
if (errs == 0) printk("HPFS: Proceeding, but your filesystem will be probably corrupted by this driver...\n");
else printk("HPFS: This driver may read bad files or crash when operating on disk with hotfixes.\n");
}
if (spareblock->n_dnode_spares != spareblock->n_dnode_spares_free) {
if (errs >= 2) {
printk("HPFS: Spare dnodes used, try chkdsk\n");
mark_dirty(s);
goto bail4;
}
hpfs_error(s, "warning: spare dnodes used, try chkdsk");
if (errs == 0) printk("HPFS: Proceeding, but your filesystem could be corrupted if you delete files or directories\n");
}
if (chk) {
unsigned a;
if (superblock->dir_band_end - superblock->dir_band_start + 1 != superblock->n_dir_band ||
superblock->dir_band_end < superblock->dir_band_start || superblock->n_dir_band > 0x4000) {
hpfs_error(s, "dir band size mismatch: dir_band_start==%08x, dir_band_end==%08x, n_dir_band==%08x",
superblock->dir_band_start, superblock->dir_band_end, superblock->n_dir_band);
goto bail4;
}
a = sbi->sb_dirband_size;
sbi->sb_dirband_size = 0;
if (hpfs_chk_sectors(s, superblock->dir_band_start, superblock->n_dir_band, "dir_band") ||
hpfs_chk_sectors(s, superblock->dir_band_bitmap, 4, "dir_band_bitmap") ||
hpfs_chk_sectors(s, superblock->bitmaps, 4, "bitmaps")) {
mark_dirty(s);
goto bail4;
}
sbi->sb_dirband_size = a;
} else printk("HPFS: You really don't want any checks? You are crazy...\n");
/* Load code page table */
if (spareblock->n_code_pages)
if (!(sbi->sb_cp_table = hpfs_load_code_page(s, spareblock->code_page_dir)))
printk("HPFS: Warning: code page support is disabled\n");
brelse(bh2);
brelse(bh1);
brelse(bh0);
root = iget_locked(s, sbi->sb_root);
if (!root)
goto bail0;
hpfs_init_inode(root);
hpfs_read_inode(root);
unlock_new_inode(root);
s->s_root = d_alloc_root(root);
if (!s->s_root) {
iput(root);
goto bail0;
}
/*
* find the root directory's . pointer & finish filling in the inode
*/
root_dno = hpfs_fnode_dno(s, sbi->sb_root);
if (root_dno)
de = map_dirent(root, root_dno, "\001\001", 2, NULL, &qbh);
if (!de)
hpfs_error(s, "unable to find root dir");
else {
root->i_atime.tv_sec = local_to_gmt(s, de->read_date);
root->i_atime.tv_nsec = 0;
root->i_mtime.tv_sec = local_to_gmt(s, de->write_date);
root->i_mtime.tv_nsec = 0;
root->i_ctime.tv_sec = local_to_gmt(s, de->creation_date);
root->i_ctime.tv_nsec = 0;
hpfs_i(root)->i_ea_size = de->ea_size;
hpfs_i(root)->i_parent_dir = root->i_ino;
if (root->i_size == -1)
root->i_size = 2048;
if (root->i_blocks == -1)
root->i_blocks = 5;
hpfs_brelse4(&qbh);
}
return 0;
bail4: brelse(bh2);
bail3: brelse(bh1);
bail2: brelse(bh0);
bail1:
bail0:
kfree(sbi->sb_bmp_dir);
kfree(sbi->sb_cp_table);
s->s_fs_info = NULL;
kfree(sbi);
return -EINVAL;
}
static struct dentry *hpfs_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
return mount_bdev(fs_type, flags, dev_name, data, hpfs_fill_super);
}
static struct file_system_type hpfs_fs_type = {
.owner = THIS_MODULE,
.name = "hpfs",
.mount = hpfs_mount,
.kill_sb = kill_block_super,
.fs_flags = FS_REQUIRES_DEV,
};
static int __init init_hpfs_fs(void)
{
int err = init_inodecache();
if (err)
goto out1;
err = register_filesystem(&hpfs_fs_type);
if (err)
goto out;
return 0;
out:
destroy_inodecache();
out1:
return err;
}
static void __exit exit_hpfs_fs(void)
{
unregister_filesystem(&hpfs_fs_type);
destroy_inodecache();
}
module_init(init_hpfs_fs)
module_exit(exit_hpfs_fs)
MODULE_LICENSE("GPL");