super.c 39.2 KB
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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>
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#include <linux/fs.h>
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#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>
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#include <linux/exportfs.h>
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#include <linux/smp_lock.h>
#include <linux/vfs.h>
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#include <linux/seq_file.h>
#include <linux/mount.h>
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#include <linux/log2.h>
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#include <linux/quotaops.h>
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#include <asm/uaccess.h>
#include "ext2.h"
#include "xattr.h"
#include "acl.h"
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#include "xip.h"
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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);
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static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
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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;
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		es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
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		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;

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	ext2_warning(sb, __func__,
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		     "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;
}

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static struct kmem_cache * ext2_inode_cachep;
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static struct inode *ext2_alloc_inode(struct super_block *sb)
{
	struct ext2_inode_info *ei;
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	ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
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	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
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	ei->i_block_alloc_info = NULL;
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	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));
}

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static void init_once(void *foo)
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{
	struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;

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	rwlock_init(&ei->i_meta_lock);
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#ifdef CONFIG_EXT2_FS_XATTR
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	init_rwsem(&ei->xattr_sem);
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#endif
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	mutex_init(&ei->truncate_mutex);
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	inode_init_once(&ei->vfs_inode);
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}
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static int init_inodecache(void)
{
	ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
					     sizeof(struct ext2_inode_info),
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					     0, (SLAB_RECLAIM_ACCOUNT|
						SLAB_MEM_SPREAD),
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					     init_once);
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	if (ext2_inode_cachep == NULL)
		return -ENOMEM;
	return 0;
}

static void destroy_inodecache(void)
{
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	kmem_cache_destroy(ext2_inode_cachep);
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}

static void ext2_clear_inode(struct inode *inode)
{
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	struct ext2_block_alloc_info *rsv = EXT2_I(inode)->i_block_alloc_info;
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#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
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	ext2_discard_reservation(inode);
	EXT2_I(inode)->i_block_alloc_info = NULL;
	if (unlikely(rsv))
		kfree(rsv);
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}

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static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs)
{
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	struct super_block *sb = vfs->mnt_sb;
	struct ext2_sb_info *sbi = EXT2_SB(sb);
	struct ext2_super_block *es = sbi->s_es;
	unsigned long def_mount_opts;
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	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);

	if (sbi->s_sb_block != 1)
		seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
	if (test_opt(sb, MINIX_DF))
		seq_puts(seq, ",minixdf");
	if (test_opt(sb, GRPID))
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		seq_puts(seq, ",grpid");
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	if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
		seq_puts(seq, ",nogrpid");
	if (sbi->s_resuid != EXT2_DEF_RESUID ||
	    le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
		seq_printf(seq, ",resuid=%u", sbi->s_resuid);
	}
	if (sbi->s_resgid != EXT2_DEF_RESGID ||
	    le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
		seq_printf(seq, ",resgid=%u", sbi->s_resgid);
	}
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	if (test_opt(sb, ERRORS_RO)) {
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		int def_errors = le16_to_cpu(es->s_errors);

		if (def_errors == EXT2_ERRORS_PANIC ||
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		    def_errors == EXT2_ERRORS_CONTINUE) {
			seq_puts(seq, ",errors=remount-ro");
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		}
	}
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	if (test_opt(sb, ERRORS_CONT))
		seq_puts(seq, ",errors=continue");
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	if (test_opt(sb, ERRORS_PANIC))
		seq_puts(seq, ",errors=panic");
	if (test_opt(sb, NO_UID32))
		seq_puts(seq, ",nouid32");
	if (test_opt(sb, DEBUG))
		seq_puts(seq, ",debug");
	if (test_opt(sb, OLDALLOC))
		seq_puts(seq, ",oldalloc");

#ifdef CONFIG_EXT2_FS_XATTR
	if (test_opt(sb, XATTR_USER))
		seq_puts(seq, ",user_xattr");
	if (!test_opt(sb, XATTR_USER) &&
	    (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
		seq_puts(seq, ",nouser_xattr");
	}
#endif

#ifdef CONFIG_EXT2_FS_POSIX_ACL
	if (test_opt(sb, POSIX_ACL))
		seq_puts(seq, ",acl");
	if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
		seq_puts(seq, ",noacl");
#endif

	if (test_opt(sb, NOBH))
		seq_puts(seq, ",nobh");
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#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

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#if defined(CONFIG_EXT2_FS_XIP)
	if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
		seq_puts(seq, ",xip");
#endif

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	if (!test_opt(sb, RESERVATION))
		seq_puts(seq, ",noreservation");

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	return 0;
}

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#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

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static const struct super_operations ext2_sops = {
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	.alloc_inode	= ext2_alloc_inode,
	.destroy_inode	= ext2_destroy_inode,
	.write_inode	= ext2_write_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,
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	.show_options	= ext2_show_options,
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#ifdef CONFIG_QUOTA
	.quota_read	= ext2_quota_read,
	.quota_write	= ext2_quota_write,
#endif
};

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static struct inode *ext2_nfs_get_inode(struct super_block *sb,
		u64 ino, u32 generation)
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{
	struct inode *inode;

	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.....
	 */
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	inode = ext2_iget(sb, ino);
	if (IS_ERR(inode))
		return ERR_CAST(inode);
	if (generation && inode->i_generation != generation) {
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		/* we didn't find the right inode.. */
		iput(inode);
		return ERR_PTR(-ESTALE);
	}
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	return inode;
}

static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
		int fh_len, int fh_type)
{
	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
				    ext2_nfs_get_inode);
}

static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
		int fh_len, int fh_type)
{
	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
				    ext2_nfs_get_inode);
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}

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/* 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.
 */
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static const struct export_operations ext2_export_ops = {
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	.fh_to_dentry = ext2_fh_to_dentry,
	.fh_to_parent = ext2_fh_to_parent,
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	.get_parent = ext2_get_parent,
};

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,
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	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
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	Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
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	Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
	Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota,
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	Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
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};

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static const match_table_t tokens = {
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	{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"},
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	{Opt_xip, "xip"},
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	{Opt_grpquota, "grpquota"},
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	{Opt_ignore, "noquota"},
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	{Opt_quota, "quota"},
	{Opt_usrquota, "usrquota"},
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	{Opt_reservation, "reservation"},
	{Opt_noreservation, "noreservation"},
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	{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:
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			clear_opt (sbi->s_mount_opt, ERRORS_CONT);
			clear_opt (sbi->s_mount_opt, ERRORS_RO);
			set_opt (sbi->s_mount_opt, ERRORS_PANIC);
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			break;
		case Opt_err_ro:
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			clear_opt (sbi->s_mount_opt, ERRORS_CONT);
			clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
			set_opt (sbi->s_mount_opt, ERRORS_RO);
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			break;
		case Opt_err_cont:
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			clear_opt (sbi->s_mount_opt, ERRORS_RO);
			clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
			set_opt (sbi->s_mount_opt, ERRORS_CONT);
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			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
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		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;
539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558

#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

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		case Opt_reservation:
			set_opt(sbi->s_mount_opt, RESERVATION);
			printk("reservations ON\n");
			break;
		case Opt_noreservation:
			clear_opt(sbi->s_mount_opt, RESERVATION);
			printk("reservations OFF\n");
			break;
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		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);
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Marcin Slusarz 已提交
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	le16_add_cpu(&es->s_mnt_count, 1);
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	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;
}

621
static int ext2_check_descriptors(struct super_block *sb)
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{
	int i;
	struct ext2_sb_info *sbi = EXT2_SB(sb);

	ext2_debug ("Checking group descriptors");

628 629
	for (i = 0; i < sbi->s_groups_count; i++) {
		struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
630 631
		ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
		ext2_fsblk_t last_block;
632

E
Eric Sandeen 已提交
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		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 (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
		    le32_to_cpu(gdp->bg_block_bitmap) > last_block)
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		{
			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;
		}
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Eric Sandeen 已提交
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		if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
		    le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
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		{
			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;
		}
E
Eric Sandeen 已提交
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		if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
658
		    le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
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		    last_block)
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		{
			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;
		}
	}
	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;
679 680 681 682 683
	int meta_blocks;
	loff_t upper_limit;

	/* This is calculated to be the largest file size for a
	 * dense, file such that the total number of
L
Linus Torvalds 已提交
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	 * sectors in the file, including data and all indirect blocks,
685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703
	 * does not exceed 2^32 -1
	 * __u32 i_blocks representing the total number of
	 * 512 bytes blocks of the file
	 */
	upper_limit = (1LL << 32) - 1;

	/* total blocks in file system block size */
	upper_limit >>= (bits - 9);


	/* indirect blocks */
	meta_blocks = 1;
	/* double indirect blocks */
	meta_blocks += 1 + (1LL << (bits-2));
	/* tripple indirect blocks */
	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));

	upper_limit -= meta_blocks;
	upper_limit <<= bits;
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	res += 1LL << (bits-2);
	res += 1LL << (2*(bits-2));
	res += 1LL << (3*(bits-2));
	res <<= bits;
	if (res > upper_limit)
		res = upper_limit;
711 712 713 714

	if (res > MAX_LFS_FILESIZE)
		res = MAX_LFS_FILESIZE;

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	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);
723
	unsigned long bg, first_meta_bg;
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Linus Torvalds 已提交
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	int has_super = 0;
	
	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;
734 735

	return ext2_group_first_block_no(sb, bg) + has_super;
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}

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;
749
	long ret = -EINVAL;
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	int blocksize = BLOCK_SIZE;
	int db_count;
	int i, j;
	__le32 features;
754
	int err;
L
Linus Torvalds 已提交
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756
	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
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Linus Torvalds 已提交
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	if (!sbi)
		return -ENOMEM;
	sb->s_fs_info = sbi;
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Miklos Szeredi 已提交
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	sbi->s_sb_block = sb_block;
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	/*
	 * 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);
809
#ifdef CONFIG_EXT2_FS_XATTR
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Linus Torvalds 已提交
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	if (def_mount_opts & EXT2_DEFM_XATTR_USER)
		set_opt(sbi->s_mount_opt, XATTR_USER);
812 813
#endif
#ifdef CONFIG_EXT2_FS_POSIX_ACL
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Linus Torvalds 已提交
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	if (def_mount_opts & EXT2_DEFM_ACL)
		set_opt(sbi->s_mount_opt, POSIX_ACL);
816
#endif
L
Linus Torvalds 已提交
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	if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
		set_opt(sbi->s_mount_opt, ERRORS_PANIC);
820
	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
V
Vasily Averin 已提交
821
		set_opt(sbi->s_mount_opt, ERRORS_CONT);
822 823
	else
		set_opt(sbi->s_mount_opt, ERRORS_RO);
L
Linus Torvalds 已提交
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	sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
	sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
	
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Martin J. Bligh 已提交
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	set_opt(sbi->s_mount_opt, RESERVATION);

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Linus Torvalds 已提交
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	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);

837 838 839
	ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
				    EXT2_MOUNT_XIP if not */

L
Linus Torvalds 已提交
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	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);

N
Nick Piggin 已提交
868
	if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) {
869 870 871 872 873
		if (!silent)
			printk("XIP: Unsupported blocksize\n");
		goto failed_mount;
	}

L
Linus Torvalds 已提交
874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907
	/* 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) ||
V
vignesh babu 已提交
908
		    !is_power_of_2(sbi->s_inode_size) ||
L
Linus Torvalds 已提交
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		    (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);
929
	if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
L
Linus Torvalds 已提交
930 931 932 933 934 935 936 937
		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 =
938
		ilog2 (EXT2_ADDR_PER_BLOCK(sb));
L
Linus Torvalds 已提交
939
	sbi->s_desc_per_block_bits =
940
		ilog2 (EXT2_DESC_PER_BLOCK(sb));
L
Linus Torvalds 已提交
941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975

	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;
E
Eric Sandeen 已提交
976 977 978
 	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;
L
Linus Torvalds 已提交
979 980 981 982 983 984 985 986
	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);
987
	sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
L
Linus Torvalds 已提交
988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008
	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);
1009

M
Martin J. Bligh 已提交
1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024
	/* per fileystem reservation list head & lock */
	spin_lock_init(&sbi->s_rsv_window_lock);
	sbi->s_rsv_window_root = RB_ROOT;
	/*
	 * Add a single, static dummy reservation to the start of the
	 * reservation window list --- it gives us a placeholder for
	 * append-at-start-of-list which makes the allocation logic
	 * _much_ simpler.
	 */
	sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
	sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
	sbi->s_rsv_window_head.rsv_alloc_hit = 0;
	sbi->s_rsv_window_head.rsv_goal_size = 0;
	ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);

1025
	err = percpu_counter_init(&sbi->s_freeblocks_counter,
1026
				ext2_count_free_blocks(sb));
1027 1028
	if (!err) {
		err = percpu_counter_init(&sbi->s_freeinodes_counter,
1029
				ext2_count_free_inodes(sb));
1030 1031 1032
	}
	if (!err) {
		err = percpu_counter_init(&sbi->s_dirs_counter,
1033
				ext2_count_dirs(sb));
1034 1035 1036 1037 1038
	}
	if (err) {
		printk(KERN_ERR "EXT2-fs: insufficient memory\n");
		goto failed_mount3;
	}
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1039 1040 1041 1042 1043 1044
	/*
	 * 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;
1045 1046 1047
	root = ext2_iget(sb, EXT2_ROOT_INO);
	if (IS_ERR(root)) {
		ret = PTR_ERR(root);
1048
		goto failed_mount3;
L
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	}
	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1051
		iput(root);
L
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		printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n");
1053
		goto failed_mount3;
L
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	}
1055 1056 1057 1058 1059 1060 1061 1062

	sb->s_root = d_alloc_root(root);
	if (!sb->s_root) {
		iput(root);
		printk(KERN_ERR "EXT2-fs: get root inode failed\n");
		ret = -ENOMEM;
		goto failed_mount3;
	}
L
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	if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1064
		ext2_warning(sb, __func__,
1065
			"mounting ext3 filesystem as ext2");
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	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;
1074 1075 1076 1077
failed_mount3:
	percpu_counter_destroy(&sbi->s_freeblocks_counter);
	percpu_counter_destroy(&sbi->s_freeinodes_counter);
	percpu_counter_destroy(&sbi->s_dirs_counter);
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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);
1089
	return ret;
L
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}

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;

1128
		if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
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			ext2_debug ("setting valid to 0\n");
1130
			es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
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			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;
1146
	unsigned long old_mount_opt = sbi->s_mount_opt;
1147 1148 1149 1150 1151 1152 1153 1154 1155
	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;
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	/*
	 * Allow the "check" option to be passed as a remount option.
	 */
1160 1161 1162 1163
	if (!parse_options (data, sbi)) {
		err = -EINVAL;
		goto restore_opts;
	}
L
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	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
		((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);

1168 1169 1170 1171 1172
	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");
1173
		err = -EINVAL;
1174 1175 1176
		goto restore_opts;
	}

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	es = sbi->s_es;
1178 1179 1180
	if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) !=
	    (old_mount_opt & EXT2_MOUNT_XIP)) &&
	    invalidate_inodes(sb))
1181
		ext2_warning(sb, __func__, "busy inodes while remounting "\
1182
			     "xip remain in cache (no functional problem)");
L
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	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));
1202 1203
			err = -EROFS;
			goto restore_opts;
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		}
		/*
		 * 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;
1216 1217 1218 1219 1220 1221
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;
L
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}

1224
static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
L
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1225
{
1226
	struct super_block *sb = dentry->d_sb;
L
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	struct ext2_sb_info *sbi = EXT2_SB(sb);
P
Pekka Enberg 已提交
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	struct ext2_super_block *es = sbi->s_es;
	u64 fsid;
L
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1230 1231

	if (test_opt (sb, MINIX_DF))
B
Badari Pulavarty 已提交
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		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();

L
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		/*
B
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		 * 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.
L
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		 */

		/*
		 * All of the blocks before first_data_block are
		 * overhead
		 */
P
Pekka Enberg 已提交
1247
		overhead = le32_to_cpu(es->s_first_data_block);
L
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		/*
		 * 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));
B
Badari Pulavarty 已提交
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		sbi->s_overhead_last = overhead;
		smp_wmb();
		sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
L
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1267 1268 1269 1270
	}

	buf->f_type = EXT2_SUPER_MAGIC;
	buf->f_bsize = sb->s_blocksize;
B
Badari Pulavarty 已提交
1271
	buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
L
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1272
	buf->f_bfree = ext2_count_free_blocks(sb);
B
Badari Pulavarty 已提交
1273
	es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
P
Pekka Enberg 已提交
1274 1275
	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))
L
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1276
		buf->f_bavail = 0;
P
Pekka Enberg 已提交
1277 1278
	buf->f_files = le32_to_cpu(es->s_inodes_count);
	buf->f_ffree = ext2_count_free_inodes(sb);
B
Badari Pulavarty 已提交
1279
	es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
L
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1280
	buf->f_namelen = EXT2_NAME_LEN;
P
Pekka Enberg 已提交
1281 1282 1283 1284
	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;
L
Linus Torvalds 已提交
1285 1286 1287
	return 0;
}

1288 1289
static int ext2_get_sb(struct file_system_type *fs_type,
	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
L
Linus Torvalds 已提交
1290
{
1291
	return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt);
L
Linus Torvalds 已提交
1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323
}

#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);
M
Martin J. Bligh 已提交
1324
		if (err < 0)
L
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1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355
			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;

1356
	mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
L
Linus Torvalds 已提交
1357 1358 1359 1360 1361 1362
	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);
M
Martin J. Bligh 已提交
1363
		if (err < 0)
L
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1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392
			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);
1393
	mutex_unlock(&inode->i_mutex);
L
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1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434
	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)