super.c 42.0 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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static int ext2_freeze(struct super_block *sb);
static int ext2_unfreeze(struct super_block *sb);
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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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	/*
	 * Make sure all delayed rcu free inodes are flushed before we
	 * destroy cache.
	 */
	rcu_barrier();
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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");
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	if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
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	    le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
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		seq_printf(seq, ",resuid=%u",
				from_kuid_munged(&init_user_ns, sbi->s_resuid));
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	}
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	if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
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	    le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
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		seq_printf(seq, ",resgid=%u",
				from_kgid_munged(&init_user_ns, sbi->s_resgid));
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	}
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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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	.freeze_fs	= ext2_freeze,
	.unfreeze_fs	= ext2_unfreeze,
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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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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;
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	kuid_t uid;
	kgid_t gid;
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	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;
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			uid = make_kuid(current_user_ns(), option);
			if (!uid_valid(uid)) {
				ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
				return -1;

			}
			sbi->s_resuid = uid;
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			break;
		case Opt_resgid:
			if (match_int(&args[0], &option))
				return 0;
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			gid = make_kgid(current_user_ns(), option);
			if (!gid_valid(gid)) {
				ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
				return -1;
			}
			sbi->s_resgid = gid;
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			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
552 553 554 555
		case Opt_xip:
#ifdef CONFIG_EXT2_FS_XIP
			set_opt (sbi->s_mount_opt, XIP);
#else
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			ext2_msg(sb, KERN_INFO, "xip option not supported");
557 558
#endif
			break;
559 560 561 562 563 564 565 566 567 568 569 570 571 572

#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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			ext2_msg(sb, KERN_INFO,
				"quota operations not supported");
575 576 577
			break;
#endif

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		case Opt_reservation:
			set_opt(sbi->s_mount_opt, RESERVATION);
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Alexey Fisher 已提交
580
			ext2_msg(sb, KERN_INFO, "reservations ON");
M
Martin J. Bligh 已提交
581 582 583
			break;
		case Opt_noreservation:
			clear_opt(sbi->s_mount_opt, RESERVATION);
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Alexey Fisher 已提交
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			ext2_msg(sb, KERN_INFO, "reservations OFF");
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Martin J. Bligh 已提交
585
			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) {
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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");
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Linus Torvalds 已提交
614
	else if ((sbi->s_mount_state & EXT2_ERROR_FS))
A
Alexey Fisher 已提交
615 616 617
		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
621 622 623
		ext2_msg(sb, KERN_WARNING,
			"warning: maximal mount count reached, "
			"running e2fsck is recommended");
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624
	else if (le32_to_cpu(es->s_checkinterval) &&
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625 626 627 628 629
		(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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	if (!le16_to_cpu(es->s_max_mnt_count))
		es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
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Marcin Slusarz 已提交
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	le16_add_cpu(&es->s_mnt_count, 1);
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Linus Torvalds 已提交
633
	if (test_opt (sb, DEBUG))
A
Alexey Fisher 已提交
634 635
		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;
}

645
static int ext2_check_descriptors(struct super_block *sb)
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{
	int i;
	struct ext2_sb_info *sbi = EXT2_SB(sb);

	ext2_debug ("Checking group descriptors");

652 653
	for (i = 0; i < sbi->s_groups_count; i++) {
		struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
654 655
		ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
		ext2_fsblk_t last_block;
656

E
Eric Sandeen 已提交
657 658 659 660 661 662 663 664
		if (i == sbi->s_groups_count - 1)
			last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
		else
			last_block = first_block +
				(EXT2_BLOCKS_PER_GROUP(sb) - 1);

		if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
		    le32_to_cpu(gdp->bg_block_bitmap) > last_block)
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		{
			ext2_error (sb, "ext2_check_descriptors",
				    "Block bitmap for group %d"
				    " not in group (block %lu)!",
				    i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
			return 0;
		}
E
Eric Sandeen 已提交
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		if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
		    le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
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		{
			ext2_error (sb, "ext2_check_descriptors",
				    "Inode bitmap for group %d"
				    " not in group (block %lu)!",
				    i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
			return 0;
		}
E
Eric Sandeen 已提交
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		if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
682
		    le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
E
Eric Sandeen 已提交
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		    last_block)
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		{
			ext2_error (sb, "ext2_check_descriptors",
				    "Inode table for group %d"
				    " not in group (block %lu)!",
				    i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
			return 0;
		}
	}
	return 1;
}

/*
 * Maximal file size.  There is a direct, and {,double-,triple-}indirect
 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
 * We need to be 1 filesystem block less than the 2^32 sector limit.
 */
static loff_t ext2_max_size(int bits)
{
	loff_t res = EXT2_NDIR_BLOCKS;
703 704 705 706 707
	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
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	 * sectors in the file, including data and all indirect blocks,
709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727
	 * does not exceed 2^32 -1
	 * __u32 i_blocks representing the total number of
	 * 512 bytes blocks of the file
	 */
	upper_limit = (1LL << 32) - 1;

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


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

	upper_limit -= meta_blocks;
	upper_limit <<= bits;
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	res += 1LL << (bits-2);
	res += 1LL << (2*(bits-2));
	res += 1LL << (3*(bits-2));
	res <<= bits;
	if (res > upper_limit)
		res = upper_limit;
735 736 737 738

	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);
747
	unsigned long bg, first_meta_bg;
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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;
758 759

	return ext2_group_first_block_no(sb, bg) + has_super;
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}

static int ext2_fill_super(struct super_block *sb, void *data, int silent)
{
	struct buffer_head * bh;
	struct ext2_sb_info * sbi;
	struct ext2_super_block * es;
	struct inode *root;
	unsigned long block;
	unsigned long sb_block = get_sb_block(&data);
	unsigned long logic_sb_block;
	unsigned long offset = 0;
	unsigned long def_mount_opts;
773
	long ret = -EINVAL;
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	int blocksize = BLOCK_SIZE;
	int db_count;
	int i, j;
	__le32 features;
778
	int err;
L
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780
	err = -ENOMEM;
781
	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
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	if (!sbi)
783
		goto failed;
784 785 786 787 788

	sbi->s_blockgroup_lock =
		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
	if (!sbi->s_blockgroup_lock) {
		kfree(sbi);
789
		goto failed;
790
	}
L
Linus Torvalds 已提交
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	sb->s_fs_info = sbi;
M
Miklos Szeredi 已提交
792
	sbi->s_sb_block = sb_block;
L
Linus Torvalds 已提交
793

794 795
	spin_lock_init(&sbi->s_lock);

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Linus Torvalds 已提交
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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
805
		ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
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		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))) {
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Alexey Fisher 已提交
821
		ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
L
Linus Torvalds 已提交
822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842
		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);
843
#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);
846 847
#endif
#ifdef CONFIG_EXT2_FS_POSIX_ACL
L
Linus Torvalds 已提交
848 849
	if (def_mount_opts & EXT2_DEFM_ACL)
		set_opt(sbi->s_mount_opt, POSIX_ACL);
850
#endif
L
Linus Torvalds 已提交
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	if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
		set_opt(sbi->s_mount_opt, ERRORS_PANIC);
854
	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
V
Vasily Averin 已提交
855
		set_opt(sbi->s_mount_opt, ERRORS_CONT);
856 857
	else
		set_opt(sbi->s_mount_opt, ERRORS_RO);
L
Linus Torvalds 已提交
858

859 860
	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
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Linus Torvalds 已提交
861
	
M
Martin J. Bligh 已提交
862 863
	set_opt(sbi->s_mount_opt, RESERVATION);

A
Alexey Fisher 已提交
864
	if (!parse_options((char *) data, sb))
L
Linus Torvalds 已提交
865 866 867 868 869 870
		goto failed_mount;

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

871 872 873
	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
878 879 880
		ext2_msg(sb, KERN_WARNING,
			"warning: feature flags set on rev 0 fs, "
			"running e2fsck is recommended");
L
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881 882 883 884 885 886 887
	/*
	 * 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
888 889 890
		ext2_msg(sb, KERN_ERR,	"error: couldn't mount because of "
		       "unsupported optional features (%x)",
			le32_to_cpu(features));
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891 892 893 894
		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
895 896 897
		ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
		       "unsupported optional features (%x)",
		       le32_to_cpu(features));
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898 899 900 901 902
		goto failed_mount;
	}

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

N
Nick Piggin 已提交
903
	if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) {
904
		if (!silent)
A
Alexey Fisher 已提交
905 906
			ext2_msg(sb, KERN_ERR,
				"error: unsupported blocksize for xip");
907 908 909
		goto failed_mount;
	}

L
Linus Torvalds 已提交
910 911 912 913 914
	/* If the blocksize doesn't match, re-read the thing.. */
	if (sb->s_blocksize != blocksize) {
		brelse(bh);

		if (!sb_set_blocksize(sb, blocksize)) {
915 916
			ext2_msg(sb, KERN_ERR,
				"error: bad blocksize %d", blocksize);
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Linus Torvalds 已提交
917 918 919 920 921 922 923
			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
924 925
			ext2_msg(sb, KERN_ERR, "error: couldn't read"
				"superblock on 2nd try");
L
Linus Torvalds 已提交
926 927 928 929 930
			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
931
			ext2_msg(sb, KERN_ERR, "error: magic mismatch");
L
Linus Torvalds 已提交
932 933 934 935 936
			goto failed_mount;
		}
	}

	sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
937
	sb->s_max_links = EXT2_LINK_MAX;
L
Linus Torvalds 已提交
938 939 940 941 942 943 944 945

	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
946
		    !is_power_of_2(sbi->s_inode_size) ||
L
Linus Torvalds 已提交
947
		    (sbi->s_inode_size > blocksize)) {
A
Alexey Fisher 已提交
948 949
			ext2_msg(sb, KERN_ERR,
				"error: unsupported inode size: %d",
L
Linus Torvalds 已提交
950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967
				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);
968
	if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
L
Linus Torvalds 已提交
969 970 971 972 973 974 975 976
		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 =
977
		ilog2 (EXT2_ADDR_PER_BLOCK(sb));
L
Linus Torvalds 已提交
978
	sbi->s_desc_per_block_bits =
979
		ilog2 (EXT2_DESC_PER_BLOCK(sb));
L
Linus Torvalds 已提交
980 981 982 983 984 985

	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
986
			ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
L
Linus Torvalds 已提交
987 988 989 990
		goto failed_mount;
	}

	if (sb->s_blocksize != sbi->s_frag_size) {
A
Alexey Fisher 已提交
991 992 993
		ext2_msg(sb, KERN_ERR,
			"error: fragsize %lu != blocksize %lu"
			"(not supported yet)",
L
Linus Torvalds 已提交
994 995 996 997 998
			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
999 1000
		ext2_msg(sb, KERN_ERR,
			"error: #blocks per group too big: %lu",
L
Linus Torvalds 已提交
1001 1002 1003 1004
			sbi->s_blocks_per_group);
		goto failed_mount;
	}
	if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
A
Alexey Fisher 已提交
1005 1006
		ext2_msg(sb, KERN_ERR,
			"error: #fragments per group too big: %lu",
L
Linus Torvalds 已提交
1007 1008 1009 1010
			sbi->s_frags_per_group);
		goto failed_mount;
	}
	if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
A
Alexey Fisher 已提交
1011 1012
		ext2_msg(sb, KERN_ERR,
			"error: #inodes per group too big: %lu",
L
Linus Torvalds 已提交
1013 1014 1015 1016 1017 1018
			sbi->s_inodes_per_group);
		goto failed_mount;
	}

	if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
		goto cantfind_ext2;
E
Eric Sandeen 已提交
1019 1020 1021
 	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
1022 1023 1024 1025
	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
1026
		ext2_msg(sb, KERN_ERR, "error: not enough memory");
L
Linus Torvalds 已提交
1027 1028
		goto failed_mount;
	}
1029
	bgl_lock_init(sbi->s_blockgroup_lock);
1030
	sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
L
Linus Torvalds 已提交
1031
	if (!sbi->s_debts) {
A
Alexey Fisher 已提交
1032
		ext2_msg(sb, KERN_ERR, "error: not enough memory");
L
Linus Torvalds 已提交
1033 1034 1035 1036 1037 1038 1039 1040
		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
1041 1042
			ext2_msg(sb, KERN_ERR,
				"error: unable to read group descriptors");
L
Linus Torvalds 已提交
1043 1044 1045 1046
			goto failed_mount_group_desc;
		}
	}
	if (!ext2_check_descriptors (sb)) {
A
Alexey Fisher 已提交
1047
		ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
L
Linus Torvalds 已提交
1048 1049 1050 1051 1052
		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);
1053

M
Martin J. Bligh 已提交
1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068
	/* 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);

1069
	err = percpu_counter_init(&sbi->s_freeblocks_counter,
1070
				ext2_count_free_blocks(sb));
1071 1072
	if (!err) {
		err = percpu_counter_init(&sbi->s_freeinodes_counter,
1073
				ext2_count_free_inodes(sb));
1074 1075 1076
	}
	if (!err) {
		err = percpu_counter_init(&sbi->s_dirs_counter,
1077
				ext2_count_dirs(sb));
1078 1079
	}
	if (err) {
A
Alexey Fisher 已提交
1080
		ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1081 1082
		goto failed_mount3;
	}
L
Linus Torvalds 已提交
1083 1084 1085 1086 1087 1088
	/*
	 * 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;
1089 1090 1091

#ifdef CONFIG_QUOTA
	sb->dq_op = &dquot_operations;
1092
	sb->s_qcop = &dquot_quotactl_ops;
1093 1094
#endif

1095 1096 1097
	root = ext2_iget(sb, EXT2_ROOT_INO);
	if (IS_ERR(root)) {
		ret = PTR_ERR(root);
1098
		goto failed_mount3;
L
Linus Torvalds 已提交
1099 1100
	}
	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1101
		iput(root);
A
Alexey Fisher 已提交
1102
		ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1103
		goto failed_mount3;
L
Linus Torvalds 已提交
1104
	}
1105

1106
	sb->s_root = d_make_root(root);
1107
	if (!sb->s_root) {
A
Alexey Fisher 已提交
1108
		ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1109 1110 1111
		ret = -ENOMEM;
		goto failed_mount3;
	}
L
Linus Torvalds 已提交
1112
	if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
A
Alexey Fisher 已提交
1113 1114
		ext2_msg(sb, KERN_WARNING,
			"warning: mounting ext3 filesystem as ext2");
1115 1116 1117
	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
1118 1119 1120 1121
	return 0;

cantfind_ext2:
	if (!silent)
A
Alexey Fisher 已提交
1122 1123 1124
		ext2_msg(sb, KERN_ERR,
			"error: can't find an ext2 filesystem on dev %s.",
			sb->s_id);
L
Linus Torvalds 已提交
1125
	goto failed_mount;
1126 1127 1128 1129
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
1130 1131 1132 1133 1134 1135 1136 1137 1138 1139
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;
1140
	kfree(sbi->s_blockgroup_lock);
L
Linus Torvalds 已提交
1141
	kfree(sbi);
1142
failed:
1143
	return ret;
L
Linus Torvalds 已提交
1144 1145
}

1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158
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.
		 */
1159 1160
		ext2_msg(sb, KERN_ERR,
		       "previous I/O error to superblock detected\n");
1161 1162 1163 1164 1165
		clear_buffer_write_io_error(sbh);
		set_buffer_uptodate(sbh);
	}
}

1166 1167
static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
			    int wait)
L
Linus Torvalds 已提交
1168
{
1169
	ext2_clear_super_error(sb);
1170
	spin_lock(&EXT2_SB(sb)->s_lock);
L
Linus Torvalds 已提交
1171 1172 1173
	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());
1174 1175
	/* unlock before we do IO */
	spin_unlock(&EXT2_SB(sb)->s_lock);
L
Linus Torvalds 已提交
1176
	mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1177 1178
	if (wait)
		sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
L
Linus Torvalds 已提交
1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190
}

/*
 * 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
1191
static int ext2_sync_fs(struct super_block *sb, int wait)
L
Linus Torvalds 已提交
1192
{
1193
	struct ext2_sb_info *sbi = EXT2_SB(sb);
C
Christoph Hellwig 已提交
1194 1195
	struct ext2_super_block *es = EXT2_SB(sb)->s_es;

1196 1197 1198 1199 1200 1201
	/*
	 * Write quota structures to quota file, sync_blockdev() will write
	 * them to disk later
	 */
	dquot_writeback_dquots(sb, -1);

1202
	spin_lock(&sbi->s_lock);
C
Christoph Hellwig 已提交
1203 1204 1205
	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
1206
	}
1207
	spin_unlock(&sbi->s_lock);
1208
	ext2_sync_super(sb, es, wait);
C
Christoph Hellwig 已提交
1209 1210 1211
	return 0;
}

J
Jan Kara 已提交
1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240
static int ext2_freeze(struct super_block *sb)
{
	struct ext2_sb_info *sbi = EXT2_SB(sb);

	/*
	 * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
	 * because we have unattached inodes and thus filesystem is not fully
	 * consistent.
	 */
	if (atomic_long_read(&sb->s_remove_count)) {
		ext2_sync_fs(sb, 1);
		return 0;
	}
	/* Set EXT2_FS_VALID flag */
	spin_lock(&sbi->s_lock);
	sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
	spin_unlock(&sbi->s_lock);
	ext2_sync_super(sb, sbi->s_es, 1);

	return 0;
}

static int ext2_unfreeze(struct super_block *sb)
{
	/* Just write sb to clear EXT2_VALID_FS flag */
	ext2_write_super(sb);

	return 0;
}
C
Christoph Hellwig 已提交
1241 1242 1243 1244 1245

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
1246 1247 1248 1249 1250 1251
}

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;
1252
	unsigned long old_mount_opt = sbi->s_mount_opt;
1253 1254 1255 1256
	struct ext2_mount_options old_opts;
	unsigned long old_sb_flags;
	int err;

1257
	spin_lock(&sbi->s_lock);
1258

1259 1260 1261 1262 1263
	/* 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
1264 1265 1266 1267

	/*
	 * Allow the "check" option to be passed as a remount option.
	 */
A
Alexey Fisher 已提交
1268
	if (!parse_options(data, sb)) {
1269 1270 1271
		err = -EINVAL;
		goto restore_opts;
	}
L
Linus Torvalds 已提交
1272 1273 1274 1275

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

1276 1277 1278 1279
	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
1280 1281
		ext2_msg(sb, KERN_WARNING,
			"warning: unsupported blocksize for xip");
1282
		err = -EINVAL;
1283 1284 1285
		goto restore_opts;
	}

L
Linus Torvalds 已提交
1286
	es = sbi->s_es;
1287
	if ((sbi->s_mount_opt ^ old_mount_opt) & EXT2_MOUNT_XIP) {
A
Alexey Fisher 已提交
1288 1289
		ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
			 "xip flag with busy inodes while remounting");
1290 1291 1292
		sbi->s_mount_opt &= ~EXT2_MOUNT_XIP;
		sbi->s_mount_opt |= old_mount_opt & EXT2_MOUNT_XIP;
	}
1293
	if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
1294
		spin_unlock(&sbi->s_lock);
L
Linus Torvalds 已提交
1295
		return 0;
1296
	}
L
Linus Torvalds 已提交
1297 1298
	if (*flags & MS_RDONLY) {
		if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1299
		    !(sbi->s_mount_state & EXT2_VALID_FS)) {
1300
			spin_unlock(&sbi->s_lock);
L
Linus Torvalds 已提交
1301
			return 0;
1302
		}
1303

L
Linus Torvalds 已提交
1304 1305 1306 1307 1308 1309
		/*
		 * 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());
1310
		spin_unlock(&sbi->s_lock);
1311

1312 1313
		err = dquot_suspend(sb, -1);
		if (err < 0) {
1314 1315 1316 1317
			spin_lock(&sbi->s_lock);
			goto restore_opts;
		}

1318
		ext2_sync_super(sb, es, 1);
L
Linus Torvalds 已提交
1319 1320 1321 1322
	} else {
		__le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
					       ~EXT2_FEATURE_RO_COMPAT_SUPP);
		if (ret) {
A
Alexey Fisher 已提交
1323 1324 1325 1326
			ext2_msg(sb, KERN_WARNING,
				"warning: couldn't remount RDWR because of "
				"unsupported optional features (%x).",
				le32_to_cpu(ret));
1327 1328
			err = -EROFS;
			goto restore_opts;
L
Linus Torvalds 已提交
1329 1330 1331 1332 1333 1334 1335 1336 1337
		}
		/*
		 * 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;
1338
		spin_unlock(&sbi->s_lock);
1339

1340
		ext2_write_super(sb);
1341

1342
		dquot_resume(sb, -1);
L
Linus Torvalds 已提交
1343
	}
1344

L
Linus Torvalds 已提交
1345
	return 0;
1346 1347 1348 1349 1350
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;
1351
	spin_unlock(&sbi->s_lock);
1352
	return err;
L
Linus Torvalds 已提交
1353 1354
}

1355
static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
L
Linus Torvalds 已提交
1356
{
1357
	struct super_block *sb = dentry->d_sb;
L
Linus Torvalds 已提交
1358
	struct ext2_sb_info *sbi = EXT2_SB(sb);
P
Pekka Enberg 已提交
1359 1360
	struct ext2_super_block *es = sbi->s_es;
	u64 fsid;
L
Linus Torvalds 已提交
1361

1362 1363
	spin_lock(&sbi->s_lock);

L
Linus Torvalds 已提交
1364
	if (test_opt (sb, MINIX_DF))
B
Badari Pulavarty 已提交
1365 1366 1367 1368 1369
		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
1370
		/*
B
Badari Pulavarty 已提交
1371 1372 1373
		 * 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
1374 1375 1376 1377 1378 1379
		 */

		/*
		 * All of the blocks before first_data_block are
		 * overhead
		 */
P
Pekka Enberg 已提交
1380
		overhead = le32_to_cpu(es->s_first_data_block);
L
Linus Torvalds 已提交
1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396

		/*
		 * 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
1397 1398 1399
		sbi->s_overhead_last = overhead;
		smp_wmb();
		sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
L
Linus Torvalds 已提交
1400 1401 1402 1403
	}

	buf->f_type = EXT2_SUPER_MAGIC;
	buf->f_bsize = sb->s_blocksize;
B
Badari Pulavarty 已提交
1404
	buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
L
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	buf->f_bfree = ext2_count_free_blocks(sb);
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	es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
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	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))
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		buf->f_bavail = 0;
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	buf->f_files = le32_to_cpu(es->s_inodes_count);
	buf->f_ffree = ext2_count_free_inodes(sb);
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	es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
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	buf->f_namelen = EXT2_NAME_LEN;
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	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;
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	spin_unlock(&sbi->s_lock);
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	return 0;
}

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static struct dentry *ext2_mount(struct file_system_type *fs_type,
	int flags, const char *dev_name, void *data)
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{
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	return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
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}

#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
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 * itself serializes the operations (and no one else should touch the files)
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 * 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;

	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)
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		return err;
	if (inode->i_size < off+len-towrite)
		i_size_write(inode, off+len-towrite);
	inode->i_version++;
	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
	mark_inode_dirty(inode);
	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)