super.c 40.7 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/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,
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			    struct ext2_super_block *es, int wait);
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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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static int ext2_sync_fs(struct super_block *sb, int wait);
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void ext2_error(struct super_block *sb, const char *function,
		const char *fmt, ...)
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{
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	struct va_format vaf;
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	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)) {
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		spin_lock(&sbi->s_lock);
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		sbi->s_mount_state |= EXT2_ERROR_FS;
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		es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
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		spin_unlock(&sbi->s_lock);
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		ext2_sync_super(sb, es, 1);
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	}

	va_start(args, fmt);
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	vaf.fmt = fmt;
	vaf.va = &args;

	printk(KERN_CRIT "EXT2-fs (%s): error: %s: %pV\n",
	       sb->s_id, function, &vaf);

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	va_end(args);

	if (test_opt(sb, ERRORS_PANIC))
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		panic("EXT2-fs: panic from previous error\n");
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	if (test_opt(sb, ERRORS_RO)) {
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		ext2_msg(sb, KERN_CRIT,
			     "error: remounting filesystem read-only");
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		sb->s_flags |= MS_RDONLY;
	}
}

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void ext2_msg(struct super_block *sb, const char *prefix,
		const char *fmt, ...)
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{
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	struct va_format vaf;
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	va_list args;

	va_start(args, fmt);
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	vaf.fmt = fmt;
	vaf.va = &args;

	printk("%sEXT2-fs (%s): %pV\n", prefix, sb->s_id, &vaf);

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	va_end(args);
}

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/*
 * This must be called with sbi->s_lock held.
 */
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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_msg(sb, KERN_WARNING,
		     "warning: updating to rev %d because of "
		     "new feature flag, running e2fsck is recommended",
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		     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);

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	dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);

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	ext2_xattr_put_super(sb);
	if (!(sb->s_flags & MS_RDONLY)) {
		struct ext2_super_block *es = sbi->s_es;

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		spin_lock(&sbi->s_lock);
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		es->s_state = cpu_to_le16(sbi->s_mount_state);
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		spin_unlock(&sbi->s_lock);
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		ext2_sync_super(sb, es, 1);
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	}
	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;
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	kfree(sbi->s_blockgroup_lock);
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	kfree(sbi);
}

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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;
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	ei->i_block_alloc_info = NULL;
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	ei->vfs_inode.i_version = 1;
	return &ei->vfs_inode;
}

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static void ext2_i_callback(struct rcu_head *head)
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{
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	struct inode *inode = container_of(head, struct inode, i_rcu);
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	kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
}

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static void ext2_destroy_inode(struct inode *inode)
{
	call_rcu(&inode->i_rcu, ext2_i_callback);
}

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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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}

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static int ext2_show_options(struct seq_file *seq, struct dentry *root)
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{
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	struct super_block *sb = root->d_sb;
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	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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	spin_lock(&sbi->s_lock);
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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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	spin_unlock(&sbi->s_lock);
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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,
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	.evict_inode	= ext2_evict_inode,
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	.put_super	= ext2_put_super,
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	.sync_fs	= ext2_sync_fs,
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	.statfs		= ext2_statfs,
	.remount_fs	= ext2_remount,
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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);

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	/*
	 * ext2_iget isn't quite right if the inode is currently unallocated!
	 * However ext2_iget currently does appropriate checks to handle stale
	 * inodes so everything is OK.
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	 */
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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}
};

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static int parse_options(char *options, struct super_block *sb)
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{
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	char *p;
	struct ext2_sb_info *sbi = EXT2_SB(sb);
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	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:
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			ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
				"not supported");
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			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:
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			ext2_msg(sb, KERN_INFO,
				"(no)acl options not supported");
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			break;
#endif
533 534 535 536
		case Opt_xip:
#ifdef CONFIG_EXT2_FS_XIP
			set_opt (sbi->s_mount_opt, XIP);
#else
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Alexey Fisher 已提交
537
			ext2_msg(sb, KERN_INFO, "xip option not supported");
538 539
#endif
			break;
540 541 542 543 544 545 546 547 548 549 550 551 552 553

#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:
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Alexey Fisher 已提交
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			ext2_msg(sb, KERN_INFO,
				"quota operations not supported");
556 557 558
			break;
#endif

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Martin J. Bligh 已提交
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		case Opt_reservation:
			set_opt(sbi->s_mount_opt, RESERVATION);
A
Alexey Fisher 已提交
561
			ext2_msg(sb, KERN_INFO, "reservations ON");
M
Martin J. Bligh 已提交
562 563 564
			break;
		case Opt_noreservation:
			clear_opt(sbi->s_mount_opt, RESERVATION);
A
Alexey Fisher 已提交
565
			ext2_msg(sb, KERN_INFO, "reservations OFF");
M
Martin J. Bligh 已提交
566
			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) {
A
Alexey Fisher 已提交
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		ext2_msg(sb, KERN_ERR,
			"error: revision level too high, "
			"forcing read-only mode");
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		res = MS_RDONLY;
	}
	if (read_only)
		return res;
	if (!(sbi->s_mount_state & EXT2_VALID_FS))
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		ext2_msg(sb, KERN_WARNING,
			"warning: mounting unchecked fs, "
			"running e2fsck is recommended");
L
Linus Torvalds 已提交
595
	else if ((sbi->s_mount_state & EXT2_ERROR_FS))
A
Alexey Fisher 已提交
596 597 598
		ext2_msg(sb, KERN_WARNING,
			"warning: mounting fs with errors, "
			"running e2fsck is recommended");
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	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))
A
Alexey Fisher 已提交
602 603 604
		ext2_msg(sb, KERN_WARNING,
			"warning: maximal mount count reached, "
			"running e2fsck is recommended");
L
Linus Torvalds 已提交
605
	else if (le32_to_cpu(es->s_checkinterval) &&
A
Alexey Fisher 已提交
606 607 608 609 610
		(le32_to_cpu(es->s_lastcheck) +
			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
		ext2_msg(sb, KERN_WARNING,
			"warning: checktime reached, "
			"running e2fsck is recommended");
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Linus Torvalds 已提交
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	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
613
	le16_add_cpu(&es->s_mnt_count, 1);
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Linus Torvalds 已提交
614
	if (test_opt (sb, DEBUG))
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Alexey Fisher 已提交
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		ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
			"bpg=%lu, ipg=%lu, mo=%04lx]",
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			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;
}

626
static int ext2_check_descriptors(struct super_block *sb)
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Linus Torvalds 已提交
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{
	int i;
	struct ext2_sb_info *sbi = EXT2_SB(sb);

	ext2_debug ("Checking group descriptors");

633 634
	for (i = 0; i < sbi->s_groups_count; i++) {
		struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
635 636
		ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
		ext2_fsblk_t last_block;
637

E
Eric Sandeen 已提交
638 639 640 641 642 643 644 645
		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)
L
Linus Torvalds 已提交
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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;
		}
E
Eric Sandeen 已提交
653 654
		if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
		    le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
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Linus Torvalds 已提交
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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
662
		if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
663
		    le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
E
Eric Sandeen 已提交
664
		    last_block)
L
Linus Torvalds 已提交
665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683
		{
			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;
684 685 686 687 688
	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
689
	 * sectors in the file, including data and all indirect blocks,
690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708
	 * 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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709 710 711 712 713 714 715

	res += 1LL << (bits-2);
	res += 1LL << (2*(bits-2));
	res += 1LL << (3*(bits-2));
	res <<= bits;
	if (res > upper_limit)
		res = upper_limit;
716 717 718 719

	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);
728
	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;
739 740

	return ext2_group_first_block_no(sb, bg) + has_super;
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741 742 743 744 745 746 747 748 749 750 751 752 753
}

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;
754
	long ret = -EINVAL;
L
Linus Torvalds 已提交
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	int blocksize = BLOCK_SIZE;
	int db_count;
	int i, j;
	__le32 features;
759
	int err;
L
Linus Torvalds 已提交
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761
	err = -ENOMEM;
762
	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
L
Linus Torvalds 已提交
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	if (!sbi)
764
		goto failed_unlock;
765 766 767 768 769

	sbi->s_blockgroup_lock =
		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
	if (!sbi->s_blockgroup_lock) {
		kfree(sbi);
770
		goto failed_unlock;
771
	}
L
Linus Torvalds 已提交
772
	sb->s_fs_info = sbi;
M
Miklos Szeredi 已提交
773
	sbi->s_sb_block = sb_block;
L
Linus Torvalds 已提交
774

775 776
	spin_lock_init(&sbi->s_lock);

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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) {
A
Alexey Fisher 已提交
786
		ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
L
Linus Torvalds 已提交
787 788 789 790 791 792 793 794 795 796 797 798 799 800 801
		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))) {
A
Alexey Fisher 已提交
802
		ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
L
Linus Torvalds 已提交
803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823
		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);
824
#ifdef CONFIG_EXT2_FS_XATTR
L
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);
827 828
#endif
#ifdef CONFIG_EXT2_FS_POSIX_ACL
L
Linus Torvalds 已提交
829 830
	if (def_mount_opts & EXT2_DEFM_ACL)
		set_opt(sbi->s_mount_opt, POSIX_ACL);
831
#endif
L
Linus Torvalds 已提交
832 833 834
	
	if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
		set_opt(sbi->s_mount_opt, ERRORS_PANIC);
835
	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
V
Vasily Averin 已提交
836
		set_opt(sbi->s_mount_opt, ERRORS_CONT);
837 838
	else
		set_opt(sbi->s_mount_opt, ERRORS_RO);
L
Linus Torvalds 已提交
839 840 841 842

	sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
	sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
	
M
Martin J. Bligh 已提交
843 844
	set_opt(sbi->s_mount_opt, RESERVATION);

A
Alexey Fisher 已提交
845
	if (!parse_options((char *) data, sb))
L
Linus Torvalds 已提交
846 847 848 849 850 851
		goto failed_mount;

	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
		((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
		 MS_POSIXACL : 0);

852 853 854
	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)))
A
Alexey Fisher 已提交
859 860 861
		ext2_msg(sb, KERN_WARNING,
			"warning: feature flags set on rev 0 fs, "
			"running e2fsck is recommended");
L
Linus Torvalds 已提交
862 863 864 865 866 867 868
	/*
	 * 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) {
A
Alexey Fisher 已提交
869 870 871
		ext2_msg(sb, KERN_ERR,	"error: couldn't mount because of "
		       "unsupported optional features (%x)",
			le32_to_cpu(features));
L
Linus Torvalds 已提交
872 873 874 875
		goto failed_mount;
	}
	if (!(sb->s_flags & MS_RDONLY) &&
	    (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
A
Alexey Fisher 已提交
876 877 878
		ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
		       "unsupported optional features (%x)",
		       le32_to_cpu(features));
L
Linus Torvalds 已提交
879 880 881 882 883
		goto failed_mount;
	}

	blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);

N
Nick Piggin 已提交
884
	if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) {
885
		if (!silent)
A
Alexey Fisher 已提交
886 887
			ext2_msg(sb, KERN_ERR,
				"error: unsupported blocksize for xip");
888 889 890
		goto failed_mount;
	}

L
Linus Torvalds 已提交
891 892 893 894 895
	/* If the blocksize doesn't match, re-read the thing.. */
	if (sb->s_blocksize != blocksize) {
		brelse(bh);

		if (!sb_set_blocksize(sb, blocksize)) {
896 897
			ext2_msg(sb, KERN_ERR,
				"error: bad blocksize %d", blocksize);
L
Linus Torvalds 已提交
898 899 900 901 902 903 904
			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) {
A
Alexey Fisher 已提交
905 906
			ext2_msg(sb, KERN_ERR, "error: couldn't read"
				"superblock on 2nd try");
L
Linus Torvalds 已提交
907 908 909 910 911
			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)) {
A
Alexey Fisher 已提交
912
			ext2_msg(sb, KERN_ERR, "error: magic mismatch");
L
Linus Torvalds 已提交
913 914 915 916 917
			goto failed_mount;
		}
	}

	sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
918
	sb->s_max_links = EXT2_LINK_MAX;
L
Linus Torvalds 已提交
919 920 921 922 923 924 925 926

	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
927
		    !is_power_of_2(sbi->s_inode_size) ||
L
Linus Torvalds 已提交
928
		    (sbi->s_inode_size > blocksize)) {
A
Alexey Fisher 已提交
929 930
			ext2_msg(sb, KERN_ERR,
				"error: unsupported inode size: %d",
L
Linus Torvalds 已提交
931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948
				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);
949
	if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
L
Linus Torvalds 已提交
950 951 952 953 954 955 956 957
		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 =
958
		ilog2 (EXT2_ADDR_PER_BLOCK(sb));
L
Linus Torvalds 已提交
959
	sbi->s_desc_per_block_bits =
960
		ilog2 (EXT2_DESC_PER_BLOCK(sb));
L
Linus Torvalds 已提交
961 962 963 964 965 966

	if (sb->s_magic != EXT2_SUPER_MAGIC)
		goto cantfind_ext2;

	if (sb->s_blocksize != bh->b_size) {
		if (!silent)
A
Alexey Fisher 已提交
967
			ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
L
Linus Torvalds 已提交
968 969 970 971
		goto failed_mount;
	}

	if (sb->s_blocksize != sbi->s_frag_size) {
A
Alexey Fisher 已提交
972 973 974
		ext2_msg(sb, KERN_ERR,
			"error: fragsize %lu != blocksize %lu"
			"(not supported yet)",
L
Linus Torvalds 已提交
975 976 977 978 979
			sbi->s_frag_size, sb->s_blocksize);
		goto failed_mount;
	}

	if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
A
Alexey Fisher 已提交
980 981
		ext2_msg(sb, KERN_ERR,
			"error: #blocks per group too big: %lu",
L
Linus Torvalds 已提交
982 983 984 985
			sbi->s_blocks_per_group);
		goto failed_mount;
	}
	if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
A
Alexey Fisher 已提交
986 987
		ext2_msg(sb, KERN_ERR,
			"error: #fragments per group too big: %lu",
L
Linus Torvalds 已提交
988 989 990 991
			sbi->s_frags_per_group);
		goto failed_mount;
	}
	if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
A
Alexey Fisher 已提交
992 993
		ext2_msg(sb, KERN_ERR,
			"error: #inodes per group too big: %lu",
L
Linus Torvalds 已提交
994 995 996 997 998 999
			sbi->s_inodes_per_group);
		goto failed_mount;
	}

	if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
		goto cantfind_ext2;
E
Eric Sandeen 已提交
1000 1001 1002
 	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
1003 1004 1005 1006
	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) {
A
Alexey Fisher 已提交
1007
		ext2_msg(sb, KERN_ERR, "error: not enough memory");
L
Linus Torvalds 已提交
1008 1009
		goto failed_mount;
	}
1010
	bgl_lock_init(sbi->s_blockgroup_lock);
1011
	sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
L
Linus Torvalds 已提交
1012
	if (!sbi->s_debts) {
A
Alexey Fisher 已提交
1013
		ext2_msg(sb, KERN_ERR, "error: not enough memory");
L
Linus Torvalds 已提交
1014 1015 1016 1017 1018 1019 1020 1021
		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]);
A
Alexey Fisher 已提交
1022 1023
			ext2_msg(sb, KERN_ERR,
				"error: unable to read group descriptors");
L
Linus Torvalds 已提交
1024 1025 1026 1027
			goto failed_mount_group_desc;
		}
	}
	if (!ext2_check_descriptors (sb)) {
A
Alexey Fisher 已提交
1028
		ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
L
Linus Torvalds 已提交
1029 1030 1031 1032 1033
		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);
1034

M
Martin J. Bligh 已提交
1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049
	/* 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);

1050
	err = percpu_counter_init(&sbi->s_freeblocks_counter,
1051
				ext2_count_free_blocks(sb));
1052 1053
	if (!err) {
		err = percpu_counter_init(&sbi->s_freeinodes_counter,
1054
				ext2_count_free_inodes(sb));
1055 1056 1057
	}
	if (!err) {
		err = percpu_counter_init(&sbi->s_dirs_counter,
1058
				ext2_count_dirs(sb));
1059 1060
	}
	if (err) {
A
Alexey Fisher 已提交
1061
		ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1062 1063
		goto failed_mount3;
	}
L
Linus Torvalds 已提交
1064 1065 1066 1067 1068 1069
	/*
	 * 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;
1070 1071 1072

#ifdef CONFIG_QUOTA
	sb->dq_op = &dquot_operations;
1073
	sb->s_qcop = &dquot_quotactl_ops;
1074 1075
#endif

1076 1077 1078
	root = ext2_iget(sb, EXT2_ROOT_INO);
	if (IS_ERR(root)) {
		ret = PTR_ERR(root);
1079
		goto failed_mount3;
L
Linus Torvalds 已提交
1080 1081
	}
	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1082
		iput(root);
A
Alexey Fisher 已提交
1083
		ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1084
		goto failed_mount3;
L
Linus Torvalds 已提交
1085
	}
1086

1087
	sb->s_root = d_make_root(root);
1088
	if (!sb->s_root) {
A
Alexey Fisher 已提交
1089
		ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1090 1091 1092
		ret = -ENOMEM;
		goto failed_mount3;
	}
L
Linus Torvalds 已提交
1093
	if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
A
Alexey Fisher 已提交
1094 1095
		ext2_msg(sb, KERN_WARNING,
			"warning: mounting ext3 filesystem as ext2");
1096 1097 1098
	if (ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY))
		sb->s_flags |= MS_RDONLY;
	ext2_write_super(sb);
L
Linus Torvalds 已提交
1099 1100 1101 1102
	return 0;

cantfind_ext2:
	if (!silent)
A
Alexey Fisher 已提交
1103 1104 1105
		ext2_msg(sb, KERN_ERR,
			"error: can't find an ext2 filesystem on dev %s.",
			sb->s_id);
L
Linus Torvalds 已提交
1106
	goto failed_mount;
1107 1108 1109 1110
failed_mount3:
	percpu_counter_destroy(&sbi->s_freeblocks_counter);
	percpu_counter_destroy(&sbi->s_freeinodes_counter);
	percpu_counter_destroy(&sbi->s_dirs_counter);
L
Linus Torvalds 已提交
1111 1112 1113 1114 1115 1116 1117 1118 1119 1120
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;
1121
	kfree(sbi->s_blockgroup_lock);
L
Linus Torvalds 已提交
1122
	kfree(sbi);
1123
failed_unlock:
1124
	return ret;
L
Linus Torvalds 已提交
1125 1126
}

1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139
static void ext2_clear_super_error(struct super_block *sb)
{
	struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;

	if (buffer_write_io_error(sbh)) {
		/*
		 * Oh, dear.  A previous attempt to write the
		 * superblock failed.  This could happen because the
		 * USB device was yanked out.  Or it could happen to
		 * be a transient write error and maybe the block will
		 * be remapped.  Nothing we can do but to retry the
		 * write and hope for the best.
		 */
1140 1141
		ext2_msg(sb, KERN_ERR,
		       "previous I/O error to superblock detected\n");
1142 1143 1144 1145 1146
		clear_buffer_write_io_error(sbh);
		set_buffer_uptodate(sbh);
	}
}

1147 1148
static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
			    int wait)
L
Linus Torvalds 已提交
1149
{
1150
	ext2_clear_super_error(sb);
1151
	spin_lock(&EXT2_SB(sb)->s_lock);
L
Linus Torvalds 已提交
1152 1153 1154
	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());
1155 1156
	/* unlock before we do IO */
	spin_unlock(&EXT2_SB(sb)->s_lock);
L
Linus Torvalds 已提交
1157
	mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1158 1159
	if (wait)
		sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
L
Linus Torvalds 已提交
1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171
}

/*
 * 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.
 */
C
Christoph Hellwig 已提交
1172
static int ext2_sync_fs(struct super_block *sb, int wait)
L
Linus Torvalds 已提交
1173
{
1174
	struct ext2_sb_info *sbi = EXT2_SB(sb);
C
Christoph Hellwig 已提交
1175 1176
	struct ext2_super_block *es = EXT2_SB(sb)->s_es;

1177
	spin_lock(&sbi->s_lock);
C
Christoph Hellwig 已提交
1178 1179 1180
	if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
		ext2_debug("setting valid to 0\n");
		es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
L
Linus Torvalds 已提交
1181
	}
1182
	spin_unlock(&sbi->s_lock);
1183
	ext2_sync_super(sb, es, wait);
C
Christoph Hellwig 已提交
1184 1185 1186 1187 1188 1189 1190 1191
	return 0;
}


void ext2_write_super(struct super_block *sb)
{
	if (!(sb->s_flags & MS_RDONLY))
		ext2_sync_fs(sb, 1);
L
Linus Torvalds 已提交
1192 1193 1194 1195 1196 1197
}

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;
1198
	unsigned long old_mount_opt = sbi->s_mount_opt;
1199 1200 1201 1202
	struct ext2_mount_options old_opts;
	unsigned long old_sb_flags;
	int err;

1203
	spin_lock(&sbi->s_lock);
1204

1205 1206 1207 1208 1209
	/* 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;
L
Linus Torvalds 已提交
1210 1211 1212 1213

	/*
	 * Allow the "check" option to be passed as a remount option.
	 */
A
Alexey Fisher 已提交
1214
	if (!parse_options(data, sb)) {
1215 1216 1217
		err = -EINVAL;
		goto restore_opts;
	}
L
Linus Torvalds 已提交
1218 1219 1220 1221

	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
		((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);

1222 1223 1224 1225
	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)) {
A
Alexey Fisher 已提交
1226 1227
		ext2_msg(sb, KERN_WARNING,
			"warning: unsupported blocksize for xip");
1228
		err = -EINVAL;
1229 1230 1231
		goto restore_opts;
	}

L
Linus Torvalds 已提交
1232
	es = sbi->s_es;
1233
	if ((sbi->s_mount_opt ^ old_mount_opt) & EXT2_MOUNT_XIP) {
A
Alexey Fisher 已提交
1234 1235
		ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
			 "xip flag with busy inodes while remounting");
1236 1237 1238
		sbi->s_mount_opt &= ~EXT2_MOUNT_XIP;
		sbi->s_mount_opt |= old_mount_opt & EXT2_MOUNT_XIP;
	}
1239
	if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
1240
		spin_unlock(&sbi->s_lock);
L
Linus Torvalds 已提交
1241
		return 0;
1242
	}
L
Linus Torvalds 已提交
1243 1244
	if (*flags & MS_RDONLY) {
		if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1245
		    !(sbi->s_mount_state & EXT2_VALID_FS)) {
1246
			spin_unlock(&sbi->s_lock);
L
Linus Torvalds 已提交
1247
			return 0;
1248
		}
1249

L
Linus Torvalds 已提交
1250 1251 1252 1253 1254 1255
		/*
		 * 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());
1256
		spin_unlock(&sbi->s_lock);
1257

1258 1259
		err = dquot_suspend(sb, -1);
		if (err < 0) {
1260 1261 1262 1263
			spin_lock(&sbi->s_lock);
			goto restore_opts;
		}

1264
		ext2_sync_super(sb, es, 1);
L
Linus Torvalds 已提交
1265 1266 1267 1268
	} else {
		__le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
					       ~EXT2_FEATURE_RO_COMPAT_SUPP);
		if (ret) {
A
Alexey Fisher 已提交
1269 1270 1271 1272
			ext2_msg(sb, KERN_WARNING,
				"warning: couldn't remount RDWR because of "
				"unsupported optional features (%x).",
				le32_to_cpu(ret));
1273 1274
			err = -EROFS;
			goto restore_opts;
L
Linus Torvalds 已提交
1275 1276 1277 1278 1279 1280 1281 1282 1283
		}
		/*
		 * 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;
1284
		spin_unlock(&sbi->s_lock);
1285

1286
		ext2_write_super(sb);
1287

1288
		dquot_resume(sb, -1);
L
Linus Torvalds 已提交
1289
	}
1290

L
Linus Torvalds 已提交
1291
	return 0;
1292 1293 1294 1295 1296
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;
1297
	spin_unlock(&sbi->s_lock);
1298
	return err;
L
Linus Torvalds 已提交
1299 1300
}

1301
static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
L
Linus Torvalds 已提交
1302
{
1303
	struct super_block *sb = dentry->d_sb;
L
Linus Torvalds 已提交
1304
	struct ext2_sb_info *sbi = EXT2_SB(sb);
P
Pekka Enberg 已提交
1305 1306
	struct ext2_super_block *es = sbi->s_es;
	u64 fsid;
L
Linus Torvalds 已提交
1307

1308 1309
	spin_lock(&sbi->s_lock);

L
Linus Torvalds 已提交
1310
	if (test_opt (sb, MINIX_DF))
B
Badari Pulavarty 已提交
1311 1312 1313 1314 1315
		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
Linus Torvalds 已提交
1316
		/*
B
Badari Pulavarty 已提交
1317 1318 1319
		 * 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
Linus Torvalds 已提交
1320 1321 1322 1323 1324 1325
		 */

		/*
		 * All of the blocks before first_data_block are
		 * overhead
		 */
P
Pekka Enberg 已提交
1326
		overhead = le32_to_cpu(es->s_first_data_block);
L
Linus Torvalds 已提交
1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342

		/*
		 * 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
1343 1344 1345
		sbi->s_overhead_last = overhead;
		smp_wmb();
		sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
L
Linus Torvalds 已提交
1346 1347 1348 1349
	}

	buf->f_type = EXT2_SUPER_MAGIC;
	buf->f_bsize = sb->s_blocksize;
B
Badari Pulavarty 已提交
1350
	buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
L
Linus Torvalds 已提交
1351
	buf->f_bfree = ext2_count_free_blocks(sb);
B
Badari Pulavarty 已提交
1352
	es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
P
Pekka Enberg 已提交
1353 1354
	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
Linus Torvalds 已提交
1355
		buf->f_bavail = 0;
P
Pekka Enberg 已提交
1356 1357
	buf->f_files = le32_to_cpu(es->s_inodes_count);
	buf->f_ffree = ext2_count_free_inodes(sb);
B
Badari Pulavarty 已提交
1358
	es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
L
Linus Torvalds 已提交
1359
	buf->f_namelen = EXT2_NAME_LEN;
P
Pekka Enberg 已提交
1360 1361 1362 1363
	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;
1364
	spin_unlock(&sbi->s_lock);
L
Linus Torvalds 已提交
1365 1366 1367
	return 0;
}

A
Al Viro 已提交
1368 1369
static struct dentry *ext2_mount(struct file_system_type *fs_type,
	int flags, const char *dev_name, void *data)
L
Linus Torvalds 已提交
1370
{
A
Al Viro 已提交
1371
	return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
L
Linus Torvalds 已提交
1372 1373 1374 1375 1376 1377
}

#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
L
Lucas De Marchi 已提交
1378
 * itself serializes the operations (and no one else should touch the files)
L
Linus Torvalds 已提交
1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402
 * 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;
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		tmp_bh.b_size = sb->s_blocksize;
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		err = ext2_get_block(inode, blk, &tmp_bh, 0);
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		if (err < 0)
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			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;

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	mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
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	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);
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		if (err < 0)
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			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:
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	if (len == towrite) {
		mutex_unlock(&inode->i_mutex);
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		return err;
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	}
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	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);
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	mutex_unlock(&inode->i_mutex);
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	return len - towrite;
}

#endif

static struct file_system_type ext2_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "ext2",
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	.mount		= ext2_mount,
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	.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();
}

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MODULE_AUTHOR("Remy Card and others");
MODULE_DESCRIPTION("Second Extended Filesystem");
MODULE_LICENSE("GPL");
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module_init(init_ext2_fs)
module_exit(exit_ext2_fs)