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/smp_lock.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"
#include "xip.h"

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

void ext2_error (struct super_block * sb, const char * function,
		 const char * fmt, ...)
{
	va_list args;
	struct ext2_sb_info *sbi = EXT2_SB(sb);
	struct ext2_super_block *es = sbi->s_es;

	if (!(sb->s_flags & MS_RDONLY)) {
		sbi->s_mount_state |= EXT2_ERROR_FS;
		es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
		ext2_sync_super(sb, es);
	}

	va_start(args, fmt);
	printk(KERN_CRIT "EXT2-fs (%s): error: %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)) {
		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, ...)
{
	va_list args;

	va_start(args, fmt);
	printk("%sEXT2-fs (%s): ", prefix, sb->s_id);
	vprintk(fmt, args);
	printk("\n");
	va_end(args);
}

void ext2_update_dynamic_rev(struct super_block *sb)
{
	struct ext2_super_block *es = EXT2_SB(sb)->s_es;

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

	ext2_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);

	lock_kernel();

	if (sb->s_dirt)
		ext2_write_super(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->s_blockgroup_lock);
	kfree(sbi);

	unlock_kernel();
}

static struct kmem_cache * ext2_inode_cachep;

static struct inode *ext2_alloc_inode(struct super_block *sb)
{
	struct ext2_inode_info *ei;
	ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
	if (!ei)
		return NULL;
	ei->i_block_alloc_info = NULL;
	ei->vfs_inode.i_version = 1;
	return &ei->vfs_inode;
}

static void ext2_destroy_inode(struct inode *inode)
{
	kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
}

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

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

static void ext2_clear_inode(struct inode *inode)
{
	struct ext2_block_alloc_info *rsv = EXT2_I(inode)->i_block_alloc_info;

	dquot_drop(inode);
	ext2_discard_reservation(inode);
	EXT2_I(inode)->i_block_alloc_info = NULL;
	if (unlikely(rsv))
		kfree(rsv);
}

static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs)
{
	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;

	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))
		seq_puts(seq, ",grpid");
	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);
	}
	if (test_opt(sb, ERRORS_RO)) {
		int def_errors = le16_to_cpu(es->s_errors);

		if (def_errors == EXT2_ERRORS_PANIC ||
		    def_errors == EXT2_ERRORS_CONTINUE) {
			seq_puts(seq, ",errors=remount-ro");
		}
	}
	if (test_opt(sb, ERRORS_CONT))
		seq_puts(seq, ",errors=continue");
	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");

#if defined(CONFIG_QUOTA)
	if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
		seq_puts(seq, ",usrquota");

	if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
		seq_puts(seq, ",grpquota");
#endif

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

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

	return 0;
}

#ifdef CONFIG_QUOTA
static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
#endif

static const struct super_operations ext2_sops = {
	.alloc_inode	= ext2_alloc_inode,
	.destroy_inode	= ext2_destroy_inode,
	.write_inode	= ext2_write_inode,
	.delete_inode	= ext2_delete_inode,
	.put_super	= ext2_put_super,
	.write_super	= ext2_write_super,
	.sync_fs	= ext2_sync_fs,
	.statfs		=