path: root/fs/ext2/super.c

/*
 *  linux/fs/ext2/super.c
 *
 * Copyright (C) 1992, 1993, 1994, 1995
 * Remy Card (card@masi.ibp.fr)
 * Laboratoire MASI - Institut Blaise Pascal
 * Universite Pierre et Marie Curie (Paris VI)
 *
 *  from
 *
 *  linux/fs/minix/inode.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *
 *  Big-endian to little-endian byte-swapping/bitmaps by
 *        David S. Miller (davem@caip.rutgers.edu), 1995
 */

#include <linux/module.h>
#include <linux/string.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/parser.h>
#include <linux/random.h>
#include <linux/buffer_head.h>
#include <linux/exportfs.h>
#include <linux/vfs.h>
#include <linux/seq_file.h>
#include <linux/mount.h>
#include <linux/log2.h>
#include <linux/quotaops.h>
#include <asm/uaccess.h>
#include "ext2.h"
#include "xattr.h"
#include "acl.h"

static void ext2_sync_super(struct super_block *sb,
			    struct ext2_super_block *es, int wait);
static int ext2_remount (struct super_block * sb, int * flags, char * data);
static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
static int ext2_sync_fs(struct super_block *sb, int wait);
static int ext2_freeze(struct super_block *sb);
static int ext2_unfreeze(struct super_block *sb);

void ext2_error(struct super_block *sb, const char *function,
		const char *fmt, ...)
{
	struct va_format vaf;
	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)) {
		spin_lock(&sbi->s_lock);
		sbi->s_mount_state |= EXT2_ERROR_FS;
		es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
		spin_unlock(&sbi->s_lock);
		ext2_sync_super(sb, es, 1);
	}

	va_start(args, fmt);

	vaf.fmt = fmt;
	vaf.va = &args;

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

	va_end(args);

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

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

	va_start(args, fmt);

	vaf.fmt = fmt;
	vaf.va = &args;

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

	va_end(args);
}

/*
 * This must be called with sbi->s_lock held.
 */
void ext2_update_dynamic_rev(struct super_block *sb)
{
	struct ext2_super_block *es = EXT2_SB(sb)->s_es;

	if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
		return;

	ext2_msg(sb, KERN_WARNING,
		     "warning: 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);

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

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

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

static struct kmem_cache * ext2_inode_cachep;

static struct inode *ext2_alloc_inode(struct super_block *sb)
{
	struct ext2_inode_info *ei;
	ei = kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
	if (!ei)
		return NULL;
	ei->i_block_alloc_info = NULL;
	ei->vfs_inode.i_version = 1;
#ifdef CONFIG_QUOTA
	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
#endif

	return &ei->vfs_inode;
}

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

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

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

	rwlock_init(&ei->i_meta_lock);
#ifdef CONFIG_EXT2_FS_XATTR
	init_rwsem(&ei->xattr_sem);
#endif
	mutex_init(&ei->truncate_mutex);
	inode_init_once(&ei->vfs_inode);
}

static int __init init_inodecache(void)
{
	ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
					     sizeof(struct ext2_inode_info),
					     0, (SLAB_RECLAIM_ACCOUNT|
						SLAB_MEM_SPREAD),
					     init_once);
	if (ext2_inode_cachep == NULL)
		return -ENOMEM;
	return 0;
}

static void destroy_inodecache(void)
{
	/*
	 * Make sure all delayed rcu free inodes are flushed before we
	 * destroy cache.
	 */
	rcu_barrier();
	kmem_cache_destroy(ext2_inode_cachep);
}

static int ext2_show_options(struct seq_file *seq, struct dentry