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, ...)
{
	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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	printk(KERN_CRIT "EXT2-fs (%s): error: %s: ", sb->s_id, function);
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	vprintk(fmt, args);
	printk("\n");
	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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{
	va_list args;

	va_start(args, fmt);
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	printk("%sEXT2-fs (%s): ", prefix, sb->s_id);
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	vprintk(fmt, args);
	printk("\n");
	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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	if (sb->s_dirt)
		ext2_write_super(sb);

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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);
	INIT_LIST_HEAD(&inode->i_dentry);
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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 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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	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,
	.write_super	= ext2_write_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);

	/* 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}
};

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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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Alexey Fisher 已提交
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			ext2_msg(sb, KERN_INFO,
				"(no)acl options not supported");
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			break;
#endif
529 530 531 532
		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
533
			ext2_msg(sb, KERN_INFO, "xip option not supported");
534 535
#endif
			break;
536 537 538 539 540 541 542 543 544 545 546 547 548 549

#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");
552 553 554
			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
557
			ext2_msg(sb, KERN_INFO, "reservations ON");
M
Martin J. Bligh 已提交
558 559 560
			break;
		case Opt_noreservation:
			clear_opt(sbi->s_mount_opt, RESERVATION);
A
Alexey Fisher 已提交
561
			ext2_msg(sb, KERN_INFO, "reservations OFF");
M
Martin J. Bligh 已提交
562
			break;
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563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579
		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
580 581 582
		ext2_msg(sb, KERN_ERR,
			"error: revision level too high, "
			"forcing read-only mode");
L
Linus Torvalds 已提交
583 584 585 586 587
		res = MS_RDONLY;
	}
	if (read_only)
		return res;
	if (!(sbi->s_mount_state & EXT2_VALID_FS))
A
Alexey Fisher 已提交
588 589 590
		ext2_msg(sb, KERN_WARNING,
			"warning: mounting unchecked fs, "
			"running e2fsck is recommended");
L
Linus Torvalds 已提交
591
	else if ((sbi->s_mount_state & EXT2_ERROR_FS))
A
Alexey Fisher 已提交
592 593 594
		ext2_msg(sb, KERN_WARNING,
			"warning: mounting fs with errors, "
			"running e2fsck is recommended");
L
Linus Torvalds 已提交
595 596 597
	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
598 599 600
		ext2_msg(sb, KERN_WARNING,
			"warning: maximal mount count reached, "
			"running e2fsck is recommended");
L
Linus Torvalds 已提交
601
	else if (le32_to_cpu(es->s_checkinterval) &&
A
Alexey Fisher 已提交
602 603 604 605 606
		(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");
L
Linus Torvalds 已提交
607 608
	if (!le16_to_cpu(es->s_max_mnt_count))
		es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
M
Marcin Slusarz 已提交
609
	le16_add_cpu(&es->s_mnt_count, 1);
L
Linus Torvalds 已提交
610
	if (test_opt (sb, DEBUG))
A
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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Linus Torvalds 已提交
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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;
}

622
static int ext2_check_descriptors(struct super_block *sb)
L
Linus Torvalds 已提交
623 624 625 626 627 628
{
	int i;
	struct ext2_sb_info *sbi = EXT2_SB(sb);

	ext2_debug ("Checking group descriptors");

629 630
	for (i = 0; i < sbi->s_groups_count; i++) {
		struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
631 632
		ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
		ext2_fsblk_t last_block;
633

E
Eric Sandeen 已提交
634 635 636 637 638 639 640 641
		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
642 643 644 645 646 647 648
		{
			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
649 650
		if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
		    le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
L
Linus Torvalds 已提交
651 652 653 654 655 656 657
		{
			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
658
		if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
659
		    le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
E
Eric Sandeen 已提交
660
		    last_block)
L
Linus Torvalds 已提交
661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679
		{
			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;
680 681 682 683 684
	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
685
	 * sectors in the file, including data and all indirect blocks,
686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704
	 * 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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Linus Torvalds 已提交
705 706 707 708 709 710 711

	res += 1LL << (bits-2);
	res += 1LL << (2*(bits-2));
	res += 1LL << (3*(bits-2));
	res <<= bits;
	if (res > upper_limit)
		res = upper_limit;
712 713 714 715

	if (res > MAX_LFS_FILESIZE)
		res = MAX_LFS_FILESIZE;

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Linus Torvalds 已提交
716 717 718 719 720 721 722 723
	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);
724
	unsigned long bg, first_meta_bg;
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Linus Torvalds 已提交
725 726 727 728 729 730 731 732 733 734
	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;
735 736

	return ext2_group_first_block_no(sb, bg) + has_super;
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Linus Torvalds 已提交
737 738 739 740 741 742 743 744 745 746 747 748 749
}

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;
750
	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;
755
	int err;
L
Linus Torvalds 已提交
756

757
	err = -ENOMEM;
758
	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
L
Linus Torvalds 已提交
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	if (!sbi)
760
		goto failed_unlock;
761 762 763 764 765

	sbi->s_blockgroup_lock =
		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
	if (!sbi->s_blockgroup_lock) {
		kfree(sbi);
766
		goto failed_unlock;
767
	}
L
Linus Torvalds 已提交
768
	sb->s_fs_info = sbi;
M
Miklos Szeredi 已提交
769
	sbi->s_sb_block = sb_block;
L
Linus Torvalds 已提交
770

771 772
	spin_lock_init(&sbi->s_lock);

L
Linus Torvalds 已提交
773 774 775 776 777 778 779 780 781
	/*
	 * 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
782
		ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
L
Linus Torvalds 已提交
783 784 785 786 787 788 789 790 791 792 793 794 795 796 797
		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
798
		ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
L
Linus Torvalds 已提交
799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819
		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);
820
#ifdef CONFIG_EXT2_FS_XATTR
L
Linus Torvalds 已提交
821 822
	if (def_mount_opts & EXT2_DEFM_XATTR_USER)
		set_opt(sbi->s_mount_opt, XATTR_USER);
823 824
#endif
#ifdef CONFIG_EXT2_FS_POSIX_ACL
L
Linus Torvalds 已提交
825 826
	if (def_mount_opts & EXT2_DEFM_ACL)
		set_opt(sbi->s_mount_opt, POSIX_ACL);
827
#endif
L
Linus Torvalds 已提交
828 829 830
	
	if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
		set_opt(sbi->s_mount_opt, ERRORS_PANIC);
831
	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
V
Vasily Averin 已提交
832
		set_opt(sbi->s_mount_opt, ERRORS_CONT);
833 834
	else
		set_opt(sbi->s_mount_opt, ERRORS_RO);
L
Linus Torvalds 已提交
835 836 837 838

	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
839 840
	set_opt(sbi->s_mount_opt, RESERVATION);

A
Alexey Fisher 已提交
841
	if (!parse_options((char *) data, sb))
L
Linus Torvalds 已提交
842 843 844 845 846 847
		goto failed_mount;

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

848 849 850
	ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
				    EXT2_MOUNT_XIP if not */

L
Linus Torvalds 已提交
851 852 853 854
	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
855 856 857
		ext2_msg(sb, KERN_WARNING,
			"warning: feature flags set on rev 0 fs, "
			"running e2fsck is recommended");
L
Linus Torvalds 已提交
858 859 860 861 862 863 864
	/*
	 * 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
865 866 867
		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
868 869 870 871
		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
872 873 874
		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
875 876 877 878 879
		goto failed_mount;
	}

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

N
Nick Piggin 已提交
880
	if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) {
881
		if (!silent)
A
Alexey Fisher 已提交
882 883
			ext2_msg(sb, KERN_ERR,
				"error: unsupported blocksize for xip");
884 885 886
		goto failed_mount;
	}

L
Linus Torvalds 已提交
887 888 889 890 891
	/* If the blocksize doesn't match, re-read the thing.. */
	if (sb->s_blocksize != blocksize) {
		brelse(bh);

		if (!sb_set_blocksize(sb, blocksize)) {
A
Alexey Fisher 已提交
892
			ext2_msg(sb, KERN_ERR, "error: blocksize is too small");
L
Linus Torvalds 已提交
893 894 895 896 897 898 899
			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
900 901
			ext2_msg(sb, KERN_ERR, "error: couldn't read"
				"superblock on 2nd try");
L
Linus Torvalds 已提交
902 903 904 905 906
			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
907
			ext2_msg(sb, KERN_ERR, "error: magic mismatch");
L
Linus Torvalds 已提交
908 909 910 911 912 913 914 915 916 917 918 919 920
			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
921
		    !is_power_of_2(sbi->s_inode_size) ||
L
Linus Torvalds 已提交
922
		    (sbi->s_inode_size > blocksize)) {
A
Alexey Fisher 已提交
923 924
			ext2_msg(sb, KERN_ERR,
				"error: unsupported inode size: %d",
L
Linus Torvalds 已提交
925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942
				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);
943
	if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
L
Linus Torvalds 已提交
944 945 946 947 948 949 950 951
		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 =
952
		ilog2 (EXT2_ADDR_PER_BLOCK(sb));
L
Linus Torvalds 已提交
953
	sbi->s_desc_per_block_bits =
954
		ilog2 (EXT2_DESC_PER_BLOCK(sb));
L
Linus Torvalds 已提交
955 956 957 958 959 960

	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
961
			ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
L
Linus Torvalds 已提交
962 963 964 965
		goto failed_mount;
	}

	if (sb->s_blocksize != sbi->s_frag_size) {
A
Alexey Fisher 已提交
966 967 968
		ext2_msg(sb, KERN_ERR,
			"error: fragsize %lu != blocksize %lu"
			"(not supported yet)",
L
Linus Torvalds 已提交
969 970 971 972 973
			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
974 975
		ext2_msg(sb, KERN_ERR,
			"error: #blocks per group too big: %lu",
L
Linus Torvalds 已提交
976 977 978 979
			sbi->s_blocks_per_group);
		goto failed_mount;
	}
	if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
A
Alexey Fisher 已提交
980 981
		ext2_msg(sb, KERN_ERR,
			"error: #fragments per group too big: %lu",
L
Linus Torvalds 已提交
982 983 984 985
			sbi->s_frags_per_group);
		goto failed_mount;
	}
	if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
A
Alexey Fisher 已提交
986 987
		ext2_msg(sb, KERN_ERR,
			"error: #inodes per group too big: %lu",
L
Linus Torvalds 已提交
988 989 990 991 992 993
			sbi->s_inodes_per_group);
		goto failed_mount;
	}

	if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
		goto cantfind_ext2;
E
Eric Sandeen 已提交
994 995 996
 	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
997 998 999 1000
	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
1001
		ext2_msg(sb, KERN_ERR, "error: not enough memory");
L
Linus Torvalds 已提交
1002 1003
		goto failed_mount;
	}
1004
	bgl_lock_init(sbi->s_blockgroup_lock);
1005
	sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
L
Linus Torvalds 已提交
1006
	if (!sbi->s_debts) {
A
Alexey Fisher 已提交
1007
		ext2_msg(sb, KERN_ERR, "error: not enough memory");
L
Linus Torvalds 已提交
1008 1009 1010 1011 1012 1013 1014 1015
		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
1016 1017
			ext2_msg(sb, KERN_ERR,
				"error: unable to read group descriptors");
L
Linus Torvalds 已提交
1018 1019 1020 1021
			goto failed_mount_group_desc;
		}
	}
	if (!ext2_check_descriptors (sb)) {
A
Alexey Fisher 已提交
1022
		ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
L
Linus Torvalds 已提交
1023 1024 1025 1026 1027
		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);
1028

M
Martin J. Bligh 已提交
1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043
	/* 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);

1044
	err = percpu_counter_init(&sbi->s_freeblocks_counter,
1045
				ext2_count_free_blocks(sb));
1046 1047
	if (!err) {
		err = percpu_counter_init(&sbi->s_freeinodes_counter,
1048
				ext2_count_free_inodes(sb));
1049 1050 1051
	}
	if (!err) {
		err = percpu_counter_init(&sbi->s_dirs_counter,
1052
				ext2_count_dirs(sb));
1053 1054
	}
	if (err) {
A
Alexey Fisher 已提交
1055
		ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1056 1057
		goto failed_mount3;
	}
L
Linus Torvalds 已提交
1058 1059 1060 1061 1062 1063
	/*
	 * 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;
1064 1065 1066

#ifdef CONFIG_QUOTA
	sb->dq_op = &dquot_operations;
1067
	sb->s_qcop = &dquot_quotactl_ops;
1068 1069
#endif

1070 1071 1072
	root = ext2_iget(sb, EXT2_ROOT_INO);
	if (IS_ERR(root)) {
		ret = PTR_ERR(root);
1073
		goto failed_mount3;
L
Linus Torvalds 已提交
1074 1075
	}
	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1076
		iput(root);
A
Alexey Fisher 已提交
1077
		ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1078
		goto failed_mount3;
L
Linus Torvalds 已提交
1079
	}
1080 1081 1082 1083

	sb->s_root = d_alloc_root(root);
	if (!sb->s_root) {
		iput(root);
A
Alexey Fisher 已提交
1084
		ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1085 1086 1087
		ret = -ENOMEM;
		goto failed_mount3;
	}
L
Linus Torvalds 已提交
1088
	if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
A
Alexey Fisher 已提交
1089 1090
		ext2_msg(sb, KERN_WARNING,
			"warning: mounting ext3 filesystem as ext2");
1091 1092 1093
	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
1094 1095 1096 1097
	return 0;

cantfind_ext2:
	if (!silent)
A
Alexey Fisher 已提交
1098 1099 1100
		ext2_msg(sb, KERN_ERR,
			"error: can't find an ext2 filesystem on dev %s.",
			sb->s_id);
L
Linus Torvalds 已提交
1101
	goto failed_mount;
1102 1103 1104 1105
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
1106 1107 1108 1109 1110 1111 1112 1113 1114 1115
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;
1116
	kfree(sbi->s_blockgroup_lock);
L
Linus Torvalds 已提交
1117
	kfree(sbi);
1118
failed_unlock:
1119
	return ret;
L
Linus Torvalds 已提交
1120 1121
}

1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134
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.
		 */
1135 1136
		ext2_msg(sb, KERN_ERR,
		       "previous I/O error to superblock detected\n");
1137 1138 1139 1140 1141
		clear_buffer_write_io_error(sbh);
		set_buffer_uptodate(sbh);
	}
}

1142 1143
static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
			    int wait)
L
Linus Torvalds 已提交
1144
{
1145
	ext2_clear_super_error(sb);
1146
	spin_lock(&EXT2_SB(sb)->s_lock);
L
Linus Torvalds 已提交
1147 1148 1149
	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());
1150 1151
	/* unlock before we do IO */
	spin_unlock(&EXT2_SB(sb)->s_lock);
L
Linus Torvalds 已提交
1152
	mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1153 1154
	if (wait)
		sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
L
Linus Torvalds 已提交
1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167
	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.
 */
C
Christoph Hellwig 已提交
1168
static int ext2_sync_fs(struct super_block *sb, int wait)
L
Linus Torvalds 已提交
1169
{
1170
	struct ext2_sb_info *sbi = EXT2_SB(sb);
C
Christoph Hellwig 已提交
1171 1172
	struct ext2_super_block *es = EXT2_SB(sb)->s_es;

1173
	spin_lock(&sbi->s_lock);
C
Christoph Hellwig 已提交
1174 1175 1176
	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
1177
	}
1178
	spin_unlock(&sbi->s_lock);
1179
	ext2_sync_super(sb, es, wait);
C
Christoph Hellwig 已提交
1180 1181 1182 1183 1184 1185 1186 1187 1188 1189
	return 0;
}


void ext2_write_super(struct super_block *sb)
{
	if (!(sb->s_flags & MS_RDONLY))
		ext2_sync_fs(sb, 1);
	else
		sb->s_dirt = 0;
L
Linus Torvalds 已提交
1190 1191 1192 1193 1194 1195
}

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;
1196
	unsigned long old_mount_opt = sbi->s_mount_opt;
1197 1198 1199 1200
	struct ext2_mount_options old_opts;
	unsigned long old_sb_flags;
	int err;

1201
	spin_lock(&sbi->s_lock);
1202

1203 1204 1205 1206 1207
	/* 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
1208 1209 1210 1211

	/*
	 * Allow the "check" option to be passed as a remount option.
	 */
A
Alexey Fisher 已提交
1212
	if (!parse_options(data, sb)) {
1213 1214 1215
		err = -EINVAL;
		goto restore_opts;
	}
L
Linus Torvalds 已提交
1216 1217 1218 1219

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

1220 1221 1222 1223
	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
1224 1225
		ext2_msg(sb, KERN_WARNING,
			"warning: unsupported blocksize for xip");
1226
		err = -EINVAL;
1227 1228 1229
		goto restore_opts;
	}

L
Linus Torvalds 已提交
1230
	es = sbi->s_es;
1231
	if ((sbi->s_mount_opt ^ old_mount_opt) & EXT2_MOUNT_XIP) {
A
Alexey Fisher 已提交
1232 1233
		ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
			 "xip flag with busy inodes while remounting");
1234 1235 1236
		sbi->s_mount_opt &= ~EXT2_MOUNT_XIP;
		sbi->s_mount_opt |= old_mount_opt & EXT2_MOUNT_XIP;
	}
1237
	if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
1238
		spin_unlock(&sbi->s_lock);
L
Linus Torvalds 已提交
1239
		return 0;
1240
	}
L
Linus Torvalds 已提交
1241 1242
	if (*flags & MS_RDONLY) {
		if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1243
		    !(sbi->s_mount_state & EXT2_VALID_FS)) {
1244
			spin_unlock(&sbi->s_lock);
L
Linus Torvalds 已提交
1245
			return 0;
1246
		}
1247

L
Linus Torvalds 已提交
1248 1249 1250 1251 1252 1253
		/*
		 * 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());
1254
		spin_unlock(&sbi->s_lock);
1255

1256 1257
		err = dquot_suspend(sb, -1);
		if (err < 0) {
1258 1259 1260 1261
			spin_lock(&sbi->s_lock);
			goto restore_opts;
		}

1262
		ext2_sync_super(sb, es, 1);
L
Linus Torvalds 已提交
1263 1264 1265 1266
	} else {
		__le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
					       ~EXT2_FEATURE_RO_COMPAT_SUPP);
		if (ret) {
A
Alexey Fisher 已提交
1267 1268 1269 1270
			ext2_msg(sb, KERN_WARNING,
				"warning: couldn't remount RDWR because of "
				"unsupported optional features (%x).",
				le32_to_cpu(ret));
1271 1272
			err = -EROFS;
			goto restore_opts;
L
Linus Torvalds 已提交
1273 1274 1275 1276 1277 1278 1279 1280 1281
		}
		/*
		 * 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;
1282
		spin_unlock(&sbi->s_lock);
1283

1284
		ext2_write_super(sb);
1285

1286
		dquot_resume(sb, -1);
L
Linus Torvalds 已提交
1287
	}
1288

L
Linus Torvalds 已提交
1289
	return 0;
1290 1291 1292 1293 1294
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;
1295
	spin_unlock(&sbi->s_lock);
1296
	return err;
L
Linus Torvalds 已提交
1297 1298
}

1299
static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
L
Linus Torvalds 已提交
1300
{
1301
	struct super_block *sb = dentry->d_sb;
L
Linus Torvalds 已提交
1302
	struct ext2_sb_info *sbi = EXT2_SB(sb);
P
Pekka Enberg 已提交
1303 1304
	struct ext2_super_block *es = sbi->s_es;
	u64 fsid;
L
Linus Torvalds 已提交
1305

1306 1307
	spin_lock(&sbi->s_lock);

L
Linus Torvalds 已提交
1308
	if (test_opt (sb, MINIX_DF))
B
Badari Pulavarty 已提交
1309 1310 1311 1312 1313
		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
1314
		/*
B
Badari Pulavarty 已提交
1315 1316 1317
		 * 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
1318 1319 1320 1321 1322 1323
		 */

		/*
		 * All of the blocks before first_data_block are
		 * overhead
		 */
P
Pekka Enberg 已提交
1324
		overhead = le32_to_cpu(es->s_first_data_block);
L
Linus Torvalds 已提交
1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340

		/*
		 * 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
1341 1342 1343
		sbi->s_overhead_last = overhead;
		smp_wmb();
		sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
L
Linus Torvalds 已提交
1344 1345 1346 1347
	}

	buf->f_type = EXT2_SUPER_MAGIC;
	buf->f_bsize = sb->s_blocksize;
B
Badari Pulavarty 已提交
1348
	buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
L
Linus Torvalds 已提交
1349
	buf->f_bfree = ext2_count_free_blocks(sb);
B
Badari Pulavarty 已提交
1350
	es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
P
Pekka Enberg 已提交
1351 1352
	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
1353
		buf->f_bavail = 0;
P
Pekka Enberg 已提交
1354 1355
	buf->f_files = le32_to_cpu(es->s_inodes_count);
	buf->f_ffree = ext2_count_free_inodes(sb);
B
Badari Pulavarty 已提交
1356
	es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
L
Linus Torvalds 已提交
1357
	buf->f_namelen = EXT2_NAME_LEN;
P
Pekka Enberg 已提交
1358 1359 1360 1361
	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;
1362
	spin_unlock(&sbi->s_lock);
L
Linus Torvalds 已提交
1363 1364 1365
	return 0;
}

A
Al Viro 已提交
1366 1367
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
1368
{
A
Al Viro 已提交
1369
	return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
L
Linus Torvalds 已提交
1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400
}

#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;
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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();
}

module_init(init_ext2_fs)
module_exit(exit_ext2_fs)