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linux-next/fs/ext2/super.c
Eric Sandeen 780dcdb211 fix inode_table test in ext234_check_descriptors 
ext[234]_check_descriptors sanity checks block group descriptor geometry at
mount time, testing whether the block bitmap, inode bitmap, and inode table
reside wholly within the blockgroup.  However, the inode table test is off
by one so that if the last block in the inode table resides on the last
block of the block group, the test incorrectly fails.  This is because it
tests the last block as (start + length) rather than (start + length - 1).

This can be seen by trying to mount a filesystem made such as:

 mkfs.ext2 -F -b 1024 -m 0 -g 256 -N 3744 fsfile 1024

which yields:

 EXT2-fs error (device loop0): ext2_check_descriptors: Inode table for group 0 not in group (block 101)!
 EXT2-fs: group descriptors corrupted!

There is a similar bug in e2fsprogs, patch already sent for that.

(I wonder if inside(), outside(), and/or in_range() should someday be
used in this and other tests throughout the ext filesystems...)

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-26 11:35:17 -07:00

1307 lines
36 KiB
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/*
* linux/fs/ext2/super.c
*
* Copyright (C) 1992, 1993, 1994, 1995
* Remy Card (card@masi.ibp.fr)
* Laboratoire MASI - Institut Blaise Pascal
* Universite Pierre et Marie Curie (Paris VI)
*
* from
*
* linux/fs/minix/inode.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*
* Big-endian to little-endian byte-swapping/bitmaps by
* David S. Miller (davem@caip.rutgers.edu), 1995
*/
#include <linux/module.h>
#include <linux/string.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/parser.h>
#include <linux/random.h>
#include <linux/buffer_head.h>
#include <linux/exportfs.h>
#include <linux/smp_lock.h>
#include <linux/vfs.h>
#include <linux/seq_file.h>
#include <linux/mount.h>
#include <asm/uaccess.h>
#include "ext2.h"
#include "xattr.h"
#include "acl.h"
#include "xip.h"
static void ext2_sync_super(struct super_block *sb,
struct ext2_super_block *es);
static int ext2_remount (struct super_block * sb, int * flags, char * data);
static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
void ext2_error (struct super_block * sb, const char * function,
const char * fmt, ...)
{
va_list args;
struct ext2_sb_info *sbi = EXT2_SB(sb);
struct ext2_super_block *es = sbi->s_es;
if (!(sb->s_flags & MS_RDONLY)) {
sbi->s_mount_state |= EXT2_ERROR_FS;
es->s_state =
cpu_to_le16(le16_to_cpu(es->s_state) | EXT2_ERROR_FS);
ext2_sync_super(sb, es);
}
va_start(args, fmt);
printk(KERN_CRIT "EXT2-fs error (device %s): %s: ",sb->s_id, function);
vprintk(fmt, args);
printk("\n");
va_end(args);
if (test_opt(sb, ERRORS_PANIC))
panic("EXT2-fs panic from previous error\n");
if (test_opt(sb, ERRORS_RO)) {
printk("Remounting filesystem read-only\n");
sb->s_flags |= MS_RDONLY;
}
}
void ext2_warning (struct super_block * sb, const char * function,
const char * fmt, ...)
{
va_list args;
va_start(args, fmt);
printk(KERN_WARNING "EXT2-fs warning (device %s): %s: ",
sb->s_id, function);
vprintk(fmt, args);
printk("\n");
va_end(args);
}
void ext2_update_dynamic_rev(struct super_block *sb)
{
struct ext2_super_block *es = EXT2_SB(sb)->s_es;
if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
return;
ext2_warning(sb, __FUNCTION__,
"updating to rev %d because of new feature flag, "
"running e2fsck is recommended",
EXT2_DYNAMIC_REV);
es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
/* leave es->s_feature_*compat flags alone */
/* es->s_uuid will be set by e2fsck if empty */
/*
* The rest of the superblock fields should be zero, and if not it
* means they are likely already in use, so leave them alone. We
* can leave it up to e2fsck to clean up any inconsistencies there.
*/
}
static void ext2_put_super (struct super_block * sb)
{
int db_count;
int i;
struct ext2_sb_info *sbi = EXT2_SB(sb);
ext2_xattr_put_super(sb);
if (!(sb->s_flags & MS_RDONLY)) {
struct ext2_super_block *es = sbi->s_es;
es->s_state = cpu_to_le16(sbi->s_mount_state);
ext2_sync_super(sb, es);
}
db_count = sbi->s_gdb_count;
for (i = 0; i < db_count; i++)
if (sbi->s_group_desc[i])
brelse (sbi->s_group_desc[i]);
kfree(sbi->s_group_desc);
kfree(sbi->s_debts);
percpu_counter_destroy(&sbi->s_freeblocks_counter);
percpu_counter_destroy(&sbi->s_freeinodes_counter);
percpu_counter_destroy(&sbi->s_dirs_counter);
brelse (sbi->s_sbh);
sb->s_fs_info = NULL;
kfree(sbi);
return;
}
static struct kmem_cache * ext2_inode_cachep;
static struct inode *ext2_alloc_inode(struct super_block *sb)
{
struct ext2_inode_info *ei;
ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
if (!ei)
return NULL;
#ifdef CONFIG_EXT2_FS_POSIX_ACL
ei->i_acl = EXT2_ACL_NOT_CACHED;
ei->i_default_acl = EXT2_ACL_NOT_CACHED;
#endif
ei->vfs_inode.i_version = 1;
return &ei->vfs_inode;
}
static void ext2_destroy_inode(struct inode *inode)
{
kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
}
static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flags)
{
struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
rwlock_init(&ei->i_meta_lock);
#ifdef CONFIG_EXT2_FS_XATTR
init_rwsem(&ei->xattr_sem);
#endif
inode_init_once(&ei->vfs_inode);
}
static int init_inodecache(void)
{
ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
sizeof(struct ext2_inode_info),
0, (SLAB_RECLAIM_ACCOUNT|
SLAB_MEM_SPREAD),
init_once);
if (ext2_inode_cachep == NULL)
return -ENOMEM;
return 0;
}
static void destroy_inodecache(void)
{
kmem_cache_destroy(ext2_inode_cachep);
}
static void ext2_clear_inode(struct inode *inode)
{
#ifdef CONFIG_EXT2_FS_POSIX_ACL
struct ext2_inode_info *ei = EXT2_I(inode);
if (ei->i_acl && ei->i_acl != EXT2_ACL_NOT_CACHED) {
posix_acl_release(ei->i_acl);
ei->i_acl = EXT2_ACL_NOT_CACHED;
}
if (ei->i_default_acl && ei->i_default_acl != EXT2_ACL_NOT_CACHED) {
posix_acl_release(ei->i_default_acl);
ei->i_default_acl = EXT2_ACL_NOT_CACHED;
}
#endif
}
static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs)
{
struct ext2_sb_info *sbi = EXT2_SB(vfs->mnt_sb);
if (sbi->s_mount_opt & EXT2_MOUNT_GRPID)
seq_puts(seq, ",grpid");
#if defined(CONFIG_QUOTA)
if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
seq_puts(seq, ",usrquota");
if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
seq_puts(seq, ",grpquota");
#endif
#if defined(CONFIG_EXT2_FS_XIP)
if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
seq_puts(seq, ",xip");
#endif
return 0;
}
#ifdef CONFIG_QUOTA
static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
#endif
static const struct super_operations ext2_sops = {
.alloc_inode = ext2_alloc_inode,
.destroy_inode = ext2_destroy_inode,
.read_inode = ext2_read_inode,
.write_inode = ext2_write_inode,
.put_inode = ext2_put_inode,
.delete_inode = ext2_delete_inode,
.put_super = ext2_put_super,
.write_super = ext2_write_super,
.statfs = ext2_statfs,
.remount_fs = ext2_remount,
.clear_inode = ext2_clear_inode,
.show_options = ext2_show_options,
#ifdef CONFIG_QUOTA
.quota_read = ext2_quota_read,
.quota_write = ext2_quota_write,
#endif
};
static struct dentry *ext2_get_dentry(struct super_block *sb, void *vobjp)
{
__u32 *objp = vobjp;
unsigned long ino = objp[0];
__u32 generation = objp[1];
struct inode *inode;
struct dentry *result;
if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
return ERR_PTR(-ESTALE);
if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
return ERR_PTR(-ESTALE);
/* iget isn't really right if the inode is currently unallocated!!
* ext2_read_inode currently does appropriate checks, but
* it might be "neater" to call ext2_get_inode first and check
* if the inode is valid.....
*/
inode = iget(sb, ino);
if (inode == NULL)
return ERR_PTR(-ENOMEM);
if (is_bad_inode(inode) ||
(generation && inode->i_generation != generation)) {
/* we didn't find the right inode.. */
iput(inode);
return ERR_PTR(-ESTALE);
}
/* now to find a dentry.
* If possible, get a well-connected one
*/
result = d_alloc_anon(inode);
if (!result) {
iput(inode);
return ERR_PTR(-ENOMEM);
}
return result;
}
/* Yes, most of these are left as NULL!!
* A NULL value implies the default, which works with ext2-like file
* systems, but can be improved upon.
* Currently only get_parent is required.
*/
static struct export_operations ext2_export_ops = {
.get_parent = ext2_get_parent,
.get_dentry = ext2_get_dentry,
};
static unsigned long get_sb_block(void **data)
{
unsigned long sb_block;
char *options = (char *) *data;
if (!options || strncmp(options, "sb=", 3) != 0)
return 1; /* Default location */
options += 3;
sb_block = simple_strtoul(options, &options, 0);
if (*options && *options != ',') {
printk("EXT2-fs: Invalid sb specification: %s\n",
(char *) *data);
return 1;
}
if (*options == ',')
options++;
*data = (void *) options;
return sb_block;
}
enum {
Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota,
Opt_usrquota, Opt_grpquota
};
static match_table_t tokens = {
{Opt_bsd_df, "bsddf"},
{Opt_minix_df, "minixdf"},
{Opt_grpid, "grpid"},
{Opt_grpid, "bsdgroups"},
{Opt_nogrpid, "nogrpid"},
{Opt_nogrpid, "sysvgroups"},
{Opt_resgid, "resgid=%u"},
{Opt_resuid, "resuid=%u"},
{Opt_sb, "sb=%u"},
{Opt_err_cont, "errors=continue"},
{Opt_err_panic, "errors=panic"},
{Opt_err_ro, "errors=remount-ro"},
{Opt_nouid32, "nouid32"},
{Opt_nocheck, "check=none"},
{Opt_nocheck, "nocheck"},
{Opt_debug, "debug"},
{Opt_oldalloc, "oldalloc"},
{Opt_orlov, "orlov"},
{Opt_nobh, "nobh"},
{Opt_user_xattr, "user_xattr"},
{Opt_nouser_xattr, "nouser_xattr"},
{Opt_acl, "acl"},
{Opt_noacl, "noacl"},
{Opt_xip, "xip"},
{Opt_grpquota, "grpquota"},
{Opt_ignore, "noquota"},
{Opt_quota, "quota"},
{Opt_usrquota, "usrquota"},
{Opt_err, NULL}
};
static int parse_options (char * options,
struct ext2_sb_info *sbi)
{
char * p;
substring_t args[MAX_OPT_ARGS];
int option;
if (!options)
return 1;
while ((p = strsep (&options, ",")) != NULL) {
int token;
if (!*p)
continue;
token = match_token(p, tokens, args);
switch (token) {
case Opt_bsd_df:
clear_opt (sbi->s_mount_opt, MINIX_DF);
break;
case Opt_minix_df:
set_opt (sbi->s_mount_opt, MINIX_DF);
break;
case Opt_grpid:
set_opt (sbi->s_mount_opt, GRPID);
break;
case Opt_nogrpid:
clear_opt (sbi->s_mount_opt, GRPID);
break;
case Opt_resuid:
if (match_int(&args[0], &option))
return 0;
sbi->s_resuid = option;
break;
case Opt_resgid:
if (match_int(&args[0], &option))
return 0;
sbi->s_resgid = option;
break;
case Opt_sb:
/* handled by get_sb_block() instead of here */
/* *sb_block = match_int(&args[0]); */
break;
case Opt_err_panic:
clear_opt (sbi->s_mount_opt, ERRORS_CONT);
clear_opt (sbi->s_mount_opt, ERRORS_RO);
set_opt (sbi->s_mount_opt, ERRORS_PANIC);
break;
case Opt_err_ro:
clear_opt (sbi->s_mount_opt, ERRORS_CONT);
clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
set_opt (sbi->s_mount_opt, ERRORS_RO);
break;
case Opt_err_cont:
clear_opt (sbi->s_mount_opt, ERRORS_RO);
clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
set_opt (sbi->s_mount_opt, ERRORS_CONT);
break;
case Opt_nouid32:
set_opt (sbi->s_mount_opt, NO_UID32);
break;
case Opt_nocheck:
clear_opt (sbi->s_mount_opt, CHECK);
break;
case Opt_debug:
set_opt (sbi->s_mount_opt, DEBUG);
break;
case Opt_oldalloc:
set_opt (sbi->s_mount_opt, OLDALLOC);
break;
case Opt_orlov:
clear_opt (sbi->s_mount_opt, OLDALLOC);
break;
case Opt_nobh:
set_opt (sbi->s_mount_opt, NOBH);
break;
#ifdef CONFIG_EXT2_FS_XATTR
case Opt_user_xattr:
set_opt (sbi->s_mount_opt, XATTR_USER);
break;
case Opt_nouser_xattr:
clear_opt (sbi->s_mount_opt, XATTR_USER);
break;
#else
case Opt_user_xattr:
case Opt_nouser_xattr:
printk("EXT2 (no)user_xattr options not supported\n");
break;
#endif
#ifdef CONFIG_EXT2_FS_POSIX_ACL
case Opt_acl:
set_opt(sbi->s_mount_opt, POSIX_ACL);
break;
case Opt_noacl:
clear_opt(sbi->s_mount_opt, POSIX_ACL);
break;
#else
case Opt_acl:
case Opt_noacl:
printk("EXT2 (no)acl options not supported\n");
break;
#endif
case Opt_xip:
#ifdef CONFIG_EXT2_FS_XIP
set_opt (sbi->s_mount_opt, XIP);
#else
printk("EXT2 xip option not supported\n");
#endif
break;
#if defined(CONFIG_QUOTA)
case Opt_quota:
case Opt_usrquota:
set_opt(sbi->s_mount_opt, USRQUOTA);
break;
case Opt_grpquota:
set_opt(sbi->s_mount_opt, GRPQUOTA);
break;
#else
case Opt_quota:
case Opt_usrquota:
case Opt_grpquota:
printk(KERN_ERR
"EXT2-fs: quota operations not supported.\n");
break;
#endif
case Opt_ignore:
break;
default:
return 0;
}
}
return 1;
}
static int ext2_setup_super (struct super_block * sb,
struct ext2_super_block * es,
int read_only)
{
int res = 0;
struct ext2_sb_info *sbi = EXT2_SB(sb);
if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
printk ("EXT2-fs warning: revision level too high, "
"forcing read-only mode\n");
res = MS_RDONLY;
}
if (read_only)
return res;
if (!(sbi->s_mount_state & EXT2_VALID_FS))
printk ("EXT2-fs warning: mounting unchecked fs, "
"running e2fsck is recommended\n");
else if ((sbi->s_mount_state & EXT2_ERROR_FS))
printk ("EXT2-fs warning: mounting fs with errors, "
"running e2fsck is recommended\n");
else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
le16_to_cpu(es->s_mnt_count) >=
(unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
printk ("EXT2-fs warning: maximal mount count reached, "
"running e2fsck is recommended\n");
else if (le32_to_cpu(es->s_checkinterval) &&
(le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds()))
printk ("EXT2-fs warning: checktime reached, "
"running e2fsck is recommended\n");
if (!le16_to_cpu(es->s_max_mnt_count))
es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1);
ext2_write_super(sb);
if (test_opt (sb, DEBUG))
printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, "
"bpg=%lu, ipg=%lu, mo=%04lx]\n",
EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
sbi->s_frag_size,
sbi->s_groups_count,
EXT2_BLOCKS_PER_GROUP(sb),
EXT2_INODES_PER_GROUP(sb),
sbi->s_mount_opt);
return res;
}
static int ext2_check_descriptors (struct super_block * sb)
{
int i;
int desc_block = 0;
struct ext2_sb_info *sbi = EXT2_SB(sb);
unsigned long first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
unsigned long last_block;
struct ext2_group_desc * gdp = NULL;
ext2_debug ("Checking group descriptors");
for (i = 0; i < sbi->s_groups_count; i++)
{
if (i == sbi->s_groups_count - 1)
last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
else
last_block = first_block +
(EXT2_BLOCKS_PER_GROUP(sb) - 1);
if ((i % EXT2_DESC_PER_BLOCK(sb)) == 0)
gdp = (struct ext2_group_desc *) sbi->s_group_desc[desc_block++]->b_data;
if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
le32_to_cpu(gdp->bg_block_bitmap) > last_block)
{
ext2_error (sb, "ext2_check_descriptors",
"Block bitmap for group %d"
" not in group (block %lu)!",
i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
return 0;
}
if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
{
ext2_error (sb, "ext2_check_descriptors",
"Inode bitmap for group %d"
" not in group (block %lu)!",
i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
return 0;
}
if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
last_block)
{
ext2_error (sb, "ext2_check_descriptors",
"Inode table for group %d"
" not in group (block %lu)!",
i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
return 0;
}
first_block += EXT2_BLOCKS_PER_GROUP(sb);
gdp++;
}
return 1;
}
/*
* Maximal file size. There is a direct, and {,double-,triple-}indirect
* block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
* We need to be 1 filesystem block less than the 2^32 sector limit.
*/
static loff_t ext2_max_size(int bits)
{
loff_t res = EXT2_NDIR_BLOCKS;
/* This constant is calculated to be the largest file size for a
* dense, 4k-blocksize file such that the total number of
* sectors in the file, including data and all indirect blocks,
* does not exceed 2^32. */
const loff_t upper_limit = 0x1ff7fffd000LL;
res += 1LL << (bits-2);
res += 1LL << (2*(bits-2));
res += 1LL << (3*(bits-2));
res <<= bits;
if (res > upper_limit)
res = upper_limit;
return res;
}
static unsigned long descriptor_loc(struct super_block *sb,
unsigned long logic_sb_block,
int nr)
{
struct ext2_sb_info *sbi = EXT2_SB(sb);
unsigned long bg, first_data_block, first_meta_bg;
int has_super = 0;
first_data_block = le32_to_cpu(sbi->s_es->s_first_data_block);
first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
nr < first_meta_bg)
return (logic_sb_block + nr + 1);
bg = sbi->s_desc_per_block * nr;
if (ext2_bg_has_super(sb, bg))
has_super = 1;
return (first_data_block + has_super + (bg * sbi->s_blocks_per_group));
}
static int ext2_fill_super(struct super_block *sb, void *data, int silent)
{
struct buffer_head * bh;
struct ext2_sb_info * sbi;
struct ext2_super_block * es;
struct inode *root;
unsigned long block;
unsigned long sb_block = get_sb_block(&data);
unsigned long logic_sb_block;
unsigned long offset = 0;
unsigned long def_mount_opts;
int blocksize = BLOCK_SIZE;
int db_count;
int i, j;
__le32 features;
sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
if (!sbi)
return -ENOMEM;
sb->s_fs_info = sbi;
/*
* See what the current blocksize for the device is, and
* use that as the blocksize. Otherwise (or if the blocksize
* is smaller than the default) use the default.
* This is important for devices that have a hardware
* sectorsize that is larger than the default.
*/
blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
if (!blocksize) {
printk ("EXT2-fs: unable to set blocksize\n");
goto failed_sbi;
}
/*
* If the superblock doesn't start on a hardware sector boundary,
* calculate the offset.
*/
if (blocksize != BLOCK_SIZE) {
logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
offset = (sb_block*BLOCK_SIZE) % blocksize;
} else {
logic_sb_block = sb_block;
}
if (!(bh = sb_bread(sb, logic_sb_block))) {
printk ("EXT2-fs: unable to read superblock\n");
goto failed_sbi;
}
/*
* Note: s_es must be initialized as soon as possible because
* some ext2 macro-instructions depend on its value
*/
es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
sbi->s_es = es;
sb->s_magic = le16_to_cpu(es->s_magic);
if (sb->s_magic != EXT2_SUPER_MAGIC)
goto cantfind_ext2;
/* Set defaults before we parse the mount options */
def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
if (def_mount_opts & EXT2_DEFM_DEBUG)
set_opt(sbi->s_mount_opt, DEBUG);
if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
set_opt(sbi->s_mount_opt, GRPID);
if (def_mount_opts & EXT2_DEFM_UID16)
set_opt(sbi->s_mount_opt, NO_UID32);
#ifdef CONFIG_EXT2_FS_XATTR
if (def_mount_opts & EXT2_DEFM_XATTR_USER)
set_opt(sbi->s_mount_opt, XATTR_USER);
#endif
#ifdef CONFIG_EXT2_FS_POSIX_ACL
if (def_mount_opts & EXT2_DEFM_ACL)
set_opt(sbi->s_mount_opt, POSIX_ACL);
#endif
if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
set_opt(sbi->s_mount_opt, ERRORS_PANIC);
else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_RO)
set_opt(sbi->s_mount_opt, ERRORS_RO);
else
set_opt(sbi->s_mount_opt, ERRORS_CONT);
sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
if (!parse_options ((char *) data, sbi))
goto failed_mount;
sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
MS_POSIXACL : 0);
ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
EXT2_MOUNT_XIP if not */
if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
(EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
printk("EXT2-fs warning: feature flags set on rev 0 fs, "
"running e2fsck is recommended\n");
/*
* Check feature flags regardless of the revision level, since we
* previously didn't change the revision level when setting the flags,
* so there is a chance incompat flags are set on a rev 0 filesystem.
*/
features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
if (features) {
printk("EXT2-fs: %s: couldn't mount because of "
"unsupported optional features (%x).\n",
sb->s_id, le32_to_cpu(features));
goto failed_mount;
}
if (!(sb->s_flags & MS_RDONLY) &&
(features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
printk("EXT2-fs: %s: couldn't mount RDWR because of "
"unsupported optional features (%x).\n",
sb->s_id, le32_to_cpu(features));
goto failed_mount;
}
blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
if ((ext2_use_xip(sb)) && ((blocksize != PAGE_SIZE) ||
(sb->s_blocksize != blocksize))) {
if (!silent)
printk("XIP: Unsupported blocksize\n");
goto failed_mount;
}
/* If the blocksize doesn't match, re-read the thing.. */
if (sb->s_blocksize != blocksize) {
brelse(bh);
if (!sb_set_blocksize(sb, blocksize)) {
printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n");
goto failed_sbi;
}
logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
offset = (sb_block*BLOCK_SIZE) % blocksize;
bh = sb_bread(sb, logic_sb_block);
if(!bh) {
printk("EXT2-fs: Couldn't read superblock on "
"2nd try.\n");
goto failed_sbi;
}
es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
sbi->s_es = es;
if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
printk ("EXT2-fs: Magic mismatch, very weird !\n");
goto failed_mount;
}
}
sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
} else {
sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
(sbi->s_inode_size & (sbi->s_inode_size - 1)) ||
(sbi->s_inode_size > blocksize)) {
printk ("EXT2-fs: unsupported inode size: %d\n",
sbi->s_inode_size);
goto failed_mount;
}
}
sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
le32_to_cpu(es->s_log_frag_size);
if (sbi->s_frag_size == 0)
goto cantfind_ext2;
sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
if (EXT2_INODE_SIZE(sb) == 0)
goto cantfind_ext2;
sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
goto cantfind_ext2;
sbi->s_itb_per_group = sbi->s_inodes_per_group /
sbi->s_inodes_per_block;
sbi->s_desc_per_block = sb->s_blocksize /
sizeof (struct ext2_group_desc);
sbi->s_sbh = bh;
sbi->s_mount_state = le16_to_cpu(es->s_state);
sbi->s_addr_per_block_bits =
ilog2 (EXT2_ADDR_PER_BLOCK(sb));
sbi->s_desc_per_block_bits =
ilog2 (EXT2_DESC_PER_BLOCK(sb));
if (sb->s_magic != EXT2_SUPER_MAGIC)
goto cantfind_ext2;
if (sb->s_blocksize != bh->b_size) {
if (!silent)
printk ("VFS: Unsupported blocksize on dev "
"%s.\n", sb->s_id);
goto failed_mount;
}
if (sb->s_blocksize != sbi->s_frag_size) {
printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n",
sbi->s_frag_size, sb->s_blocksize);
goto failed_mount;
}
if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
printk ("EXT2-fs: #blocks per group too big: %lu\n",
sbi->s_blocks_per_group);
goto failed_mount;
}
if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
printk ("EXT2-fs: #fragments per group too big: %lu\n",
sbi->s_frags_per_group);
goto failed_mount;
}
if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
printk ("EXT2-fs: #inodes per group too big: %lu\n",
sbi->s_inodes_per_group);
goto failed_mount;
}
if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
goto cantfind_ext2;
sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
le32_to_cpu(es->s_first_data_block) - 1)
/ EXT2_BLOCKS_PER_GROUP(sb)) + 1;
db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
EXT2_DESC_PER_BLOCK(sb);
sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
if (sbi->s_group_desc == NULL) {
printk ("EXT2-fs: not enough memory\n");
goto failed_mount;
}
bgl_lock_init(&sbi->s_blockgroup_lock);
sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
if (!sbi->s_debts) {
printk ("EXT2-fs: not enough memory\n");
goto failed_mount_group_desc;
}
for (i = 0; i < db_count; i++) {
block = descriptor_loc(sb, logic_sb_block, i);
sbi->s_group_desc[i] = sb_bread(sb, block);
if (!sbi->s_group_desc[i]) {
for (j = 0; j < i; j++)
brelse (sbi->s_group_desc[j]);
printk ("EXT2-fs: unable to read group descriptors\n");
goto failed_mount_group_desc;
}
}
if (!ext2_check_descriptors (sb)) {
printk ("EXT2-fs: group descriptors corrupted!\n");
goto failed_mount2;
}
sbi->s_gdb_count = db_count;
get_random_bytes(&sbi->s_next_generation, sizeof(u32));
spin_lock_init(&sbi->s_next_gen_lock);
percpu_counter_init(&sbi->s_freeblocks_counter,
ext2_count_free_blocks(sb));
percpu_counter_init(&sbi->s_freeinodes_counter,
ext2_count_free_inodes(sb));
percpu_counter_init(&sbi->s_dirs_counter,
ext2_count_dirs(sb));
/*
* set up enough so that it can read an inode
*/
sb->s_op = &ext2_sops;
sb->s_export_op = &ext2_export_ops;
sb->s_xattr = ext2_xattr_handlers;
root = iget(sb, EXT2_ROOT_INO);
sb->s_root = d_alloc_root(root);
if (!sb->s_root) {
iput(root);
printk(KERN_ERR "EXT2-fs: get root inode failed\n");
goto failed_mount3;
}
if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
dput(sb->s_root);
sb->s_root = NULL;
printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n");
goto failed_mount3;
}
if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
ext2_warning(sb, __FUNCTION__,
"mounting ext3 filesystem as ext2");
ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY);
return 0;
cantfind_ext2:
if (!silent)
printk("VFS: Can't find an ext2 filesystem on dev %s.\n",
sb->s_id);
goto failed_mount;
failed_mount3:
percpu_counter_destroy(&sbi->s_freeblocks_counter);
percpu_counter_destroy(&sbi->s_freeinodes_counter);
percpu_counter_destroy(&sbi->s_dirs_counter);
failed_mount2:
for (i = 0; i < db_count; i++)
brelse(sbi->s_group_desc[i]);
failed_mount_group_desc:
kfree(sbi->s_group_desc);
kfree(sbi->s_debts);
failed_mount:
brelse(bh);
failed_sbi:
sb->s_fs_info = NULL;
kfree(sbi);
return -EINVAL;
}
static void ext2_commit_super (struct super_block * sb,
struct ext2_super_block * es)
{
es->s_wtime = cpu_to_le32(get_seconds());
mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
sb->s_dirt = 0;
}
static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es)
{
es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
es->s_wtime = cpu_to_le32(get_seconds());
mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
sb->s_dirt = 0;
}
/*
* In the second extended file system, it is not necessary to
* write the super block since we use a mapping of the
* disk super block in a buffer.
*
* However, this function is still used to set the fs valid
* flags to 0. We need to set this flag to 0 since the fs
* may have been checked while mounted and e2fsck may have
* set s_state to EXT2_VALID_FS after some corrections.
*/
void ext2_write_super (struct super_block * sb)
{
struct ext2_super_block * es;
lock_kernel();
if (!(sb->s_flags & MS_RDONLY)) {
es = EXT2_SB(sb)->s_es;
if (le16_to_cpu(es->s_state) & EXT2_VALID_FS) {
ext2_debug ("setting valid to 0\n");
es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) &
~EXT2_VALID_FS);
es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
es->s_mtime = cpu_to_le32(get_seconds());
ext2_sync_super(sb, es);
} else
ext2_commit_super (sb, es);
}
sb->s_dirt = 0;
unlock_kernel();
}
static int ext2_remount (struct super_block * sb, int * flags, char * data)
{
struct ext2_sb_info * sbi = EXT2_SB(sb);
struct ext2_super_block * es;
unsigned long old_mount_opt = sbi->s_mount_opt;
struct ext2_mount_options old_opts;
unsigned long old_sb_flags;
int err;
/* Store the old options */
old_sb_flags = sb->s_flags;
old_opts.s_mount_opt = sbi->s_mount_opt;
old_opts.s_resuid = sbi->s_resuid;
old_opts.s_resgid = sbi->s_resgid;
/*
* Allow the "check" option to be passed as a remount option.
*/
if (!parse_options (data, sbi)) {
err = -EINVAL;
goto restore_opts;
}
sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
EXT2_MOUNT_XIP if not */
if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) {
printk("XIP: Unsupported blocksize\n");
err = -EINVAL;
goto restore_opts;
}
es = sbi->s_es;
if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) !=
(old_mount_opt & EXT2_MOUNT_XIP)) &&
invalidate_inodes(sb))
ext2_warning(sb, __FUNCTION__, "busy inodes while remounting "\
"xip remain in cache (no functional problem)");
if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
return 0;
if (*flags & MS_RDONLY) {
if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
!(sbi->s_mount_state & EXT2_VALID_FS))
return 0;
/*
* OK, we are remounting a valid rw partition rdonly, so set
* the rdonly flag and then mark the partition as valid again.
*/
es->s_state = cpu_to_le16(sbi->s_mount_state);
es->s_mtime = cpu_to_le32(get_seconds());
} else {
__le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
~EXT2_FEATURE_RO_COMPAT_SUPP);
if (ret) {
printk("EXT2-fs: %s: couldn't remount RDWR because of "
"unsupported optional features (%x).\n",
sb->s_id, le32_to_cpu(ret));
err = -EROFS;
goto restore_opts;
}
/*
* Mounting a RDONLY partition read-write, so reread and
* store the current valid flag. (It may have been changed
* by e2fsck since we originally mounted the partition.)
*/
sbi->s_mount_state = le16_to_cpu(es->s_state);
if (!ext2_setup_super (sb, es, 0))
sb->s_flags &= ~MS_RDONLY;
}
ext2_sync_super(sb, es);
return 0;
restore_opts:
sbi->s_mount_opt = old_opts.s_mount_opt;
sbi->s_resuid = old_opts.s_resuid;
sbi->s_resgid = old_opts.s_resgid;
sb->s_flags = old_sb_flags;
return err;
}
static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
{
struct super_block *sb = dentry->d_sb;
struct ext2_sb_info *sbi = EXT2_SB(sb);
struct ext2_super_block *es = sbi->s_es;
u64 fsid;
if (test_opt (sb, MINIX_DF))
sbi->s_overhead_last = 0;
else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
unsigned long i, overhead = 0;
smp_rmb();
/*
* Compute the overhead (FS structures). This is constant
* for a given filesystem unless the number of block groups
* changes so we cache the previous value until it does.
*/
/*
* All of the blocks before first_data_block are
* overhead
*/
overhead = le32_to_cpu(es->s_first_data_block);
/*
* Add the overhead attributed to the superblock and
* block group descriptors. If the sparse superblocks
* feature is turned on, then not all groups have this.
*/
for (i = 0; i < sbi->s_groups_count; i++)
overhead += ext2_bg_has_super(sb, i) +
ext2_bg_num_gdb(sb, i);
/*
* Every block group has an inode bitmap, a block
* bitmap, and an inode table.
*/
overhead += (sbi->s_groups_count *
(2 + sbi->s_itb_per_group));
sbi->s_overhead_last = overhead;
smp_wmb();
sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
}
buf->f_type = EXT2_SUPER_MAGIC;
buf->f_bsize = sb->s_blocksize;
buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
buf->f_bfree = ext2_count_free_blocks(sb);
es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
buf->f_bavail = 0;
buf->f_files = le32_to_cpu(es->s_inodes_count);
buf->f_ffree = ext2_count_free_inodes(sb);
es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
buf->f_namelen = EXT2_NAME_LEN;
fsid = le64_to_cpup((void *)es->s_uuid) ^
le64_to_cpup((void *)es->s_uuid + sizeof(u64));
buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
return 0;
}
static int ext2_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data, struct vfsmount *mnt)
{
return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt);
}
#ifdef CONFIG_QUOTA
/* Read data from quotafile - avoid pagecache and such because we cannot afford
* acquiring the locks... As quota files are never truncated and quota code
* itself serializes the operations (and noone else should touch the files)
* we don't have to be afraid of races */
static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
size_t len, loff_t off)
{
struct inode *inode = sb_dqopt(sb)->files[type];
sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
int err = 0;
int offset = off & (sb->s_blocksize - 1);
int tocopy;
size_t toread;
struct buffer_head tmp_bh;
struct buffer_head *bh;
loff_t i_size = i_size_read(inode);
if (off > i_size)
return 0;
if (off+len > i_size)
len = i_size-off;
toread = len;
while (toread > 0) {
tocopy = sb->s_blocksize - offset < toread ?
sb->s_blocksize - offset : toread;
tmp_bh.b_state = 0;
err = ext2_get_block(inode, blk, &tmp_bh, 0);
if (err)
return err;
if (!buffer_mapped(&tmp_bh)) /* A hole? */
memset(data, 0, tocopy);
else {
bh = sb_bread(sb, tmp_bh.b_blocknr);
if (!bh)
return -EIO;
memcpy(data, bh->b_data+offset, tocopy);
brelse(bh);
}
offset = 0;
toread -= tocopy;
data += tocopy;
blk++;
}
return len;
}
/* Write to quotafile */
static ssize_t ext2_quota_write(struct super_block *sb, int type,
const char *data, size_t len, loff_t off)
{
struct inode *inode = sb_dqopt(sb)->files[type];
sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
int err = 0;
int offset = off & (sb->s_blocksize - 1);
int tocopy;
size_t towrite = len;
struct buffer_head tmp_bh;
struct buffer_head *bh;
mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
while (towrite > 0) {
tocopy = sb->s_blocksize - offset < towrite ?
sb->s_blocksize - offset : towrite;
tmp_bh.b_state = 0;
err = ext2_get_block(inode, blk, &tmp_bh, 1);
if (err)
goto out;
if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
bh = sb_bread(sb, tmp_bh.b_blocknr);
else
bh = sb_getblk(sb, tmp_bh.b_blocknr);
if (!bh) {
err = -EIO;
goto out;
}
lock_buffer(bh);
memcpy(bh->b_data+offset, data, tocopy);
flush_dcache_page(bh->b_page);
set_buffer_uptodate(bh);
mark_buffer_dirty(bh);
unlock_buffer(bh);
brelse(bh);
offset = 0;
towrite -= tocopy;
data += tocopy;
blk++;
}
out:
if (len == towrite)
return err;
if (inode->i_size < off+len-towrite)
i_size_write(inode, off+len-towrite);
inode->i_version++;
inode->i_mtime = inode->i_ctime = CURRENT_TIME;
mark_inode_dirty(inode);
mutex_unlock(&inode->i_mutex);
return len - towrite;
}
#endif
static struct file_system_type ext2_fs_type = {
.owner = THIS_MODULE,
.name = "ext2",
.get_sb = ext2_get_sb,
.kill_sb = kill_block_super,
.fs_flags = FS_REQUIRES_DEV,
};
static int __init init_ext2_fs(void)
{
int err = init_ext2_xattr();
if (err)
return err;
err = init_inodecache();
if (err)
goto out1;
err = register_filesystem(&ext2_fs_type);
if (err)
goto out;
return 0;
out:
destroy_inodecache();
out1:
exit_ext2_xattr();
return err;
}
static void __exit exit_ext2_fs(void)
{
unregister_filesystem(&ext2_fs_type);
destroy_inodecache();
exit_ext2_xattr();
}
module_init(init_ext2_fs)
module_exit(exit_ext2_fs)
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