patch-2.4.15 linux/fs/ext3/super.c

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diff -u --recursive --new-file v2.4.14/linux/fs/ext3/super.c linux/fs/ext3/super.c
@@ -0,0 +1,1745 @@
+/*
+ *  linux/fs/ext3/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/config.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/fs.h>
+#include <linux/sched.h>
+#include <linux/jbd.h>
+#include <linux/ext3_fs.h>
+#include <linux/ext3_jbd.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/locks.h>
+#include <linux/blkdev.h>
+#include <linux/smp_lock.h>
+#include <asm/uaccess.h>
+
+#ifdef CONFIG_JBD_DEBUG
+static int ext3_ro_after; /* Make fs read-only after this many jiffies */
+#endif
+
+static int ext3_load_journal(struct super_block *, struct ext3_super_block *);
+static int ext3_create_journal(struct super_block *, struct ext3_super_block *,
+			       int);
+static void ext3_commit_super (struct super_block * sb,
+			       struct ext3_super_block * es,
+			       int sync);
+static void ext3_mark_recovery_complete(struct super_block * sb,
+					struct ext3_super_block * es);
+static void ext3_clear_journal_err(struct super_block * sb,
+				   struct ext3_super_block * es);
+
+#ifdef CONFIG_JBD_DEBUG
+int journal_no_write[2];
+
+/*
+ * Debug code for turning filesystems "read-only" after a specified
+ * amount of time.  This is for crash/recovery testing.
+ */
+
+static void make_rdonly(kdev_t dev, int *no_write)
+{
+	if (dev) {
+		printk(KERN_WARNING "Turning device %s read-only\n", 
+		       bdevname(dev));
+		*no_write = 0xdead0000 + dev;
+	}
+}
+
+static void turn_fs_readonly(unsigned long arg)
+{
+	struct super_block *sb = (struct super_block *)arg;
+
+	make_rdonly(sb->s_dev, &journal_no_write[0]);
+	make_rdonly(EXT3_SB(sb)->s_journal->j_dev, &journal_no_write[1]);
+	wake_up(&EXT3_SB(sb)->ro_wait_queue);
+}
+
+static void setup_ro_after(struct super_block *sb)
+{
+	struct ext3_sb_info *sbi = EXT3_SB(sb);
+	init_timer(&sbi->turn_ro_timer);
+	if (ext3_ro_after) {
+		printk(KERN_DEBUG "fs will go read-only in %d jiffies\n",
+		       ext3_ro_after);
+		init_waitqueue_head(&sbi->ro_wait_queue);
+		journal_no_write[0] = 0;
+		journal_no_write[1] = 0;
+		sbi->turn_ro_timer.function = turn_fs_readonly;
+		sbi->turn_ro_timer.data = (unsigned long)sb;
+		sbi->turn_ro_timer.expires = jiffies + ext3_ro_after;
+		ext3_ro_after = 0;
+		add_timer(&sbi->turn_ro_timer);
+	}
+}
+
+static void clear_ro_after(struct super_block *sb)
+{
+	del_timer_sync(&EXT3_SB(sb)->turn_ro_timer);
+	journal_no_write[0] = 0;
+	journal_no_write[1] = 0;
+	ext3_ro_after = 0;
+}
+#else
+#define setup_ro_after(sb)	do {} while (0)
+#define clear_ro_after(sb)	do {} while (0)
+#endif
+
+
+static char error_buf[1024];
+
+/* Determine the appropriate response to ext3_error on a given filesystem */
+
+static int ext3_error_behaviour(struct super_block *sb)
+{
+	/* First check for mount-time options */
+	if (test_opt (sb, ERRORS_PANIC))
+		return EXT3_ERRORS_PANIC;
+	if (test_opt (sb, ERRORS_RO))
+		return EXT3_ERRORS_RO;
+	if (test_opt (sb, ERRORS_CONT))
+		return EXT3_ERRORS_CONTINUE;
+	
+	/* If no overrides were specified on the mount, then fall back
+	 * to the default behaviour set in the filesystem's superblock
+	 * on disk. */
+	switch (le16_to_cpu(sb->u.ext3_sb.s_es->s_errors)) {
+	case EXT3_ERRORS_PANIC:
+		return EXT3_ERRORS_PANIC;
+	case EXT3_ERRORS_RO:
+		return EXT3_ERRORS_RO;
+	default:
+		break;
+	}
+	return EXT3_ERRORS_CONTINUE;
+}
+
+/* Deal with the reporting of failure conditions on a filesystem such as
+ * inconsistencies detected or read IO failures.
+ *
+ * On ext2, we can store the error state of the filesystem in the
+ * superblock.  That is not possible on ext3, because we may have other
+ * write ordering constraints on the superblock which prevent us from
+ * writing it out straight away; and given that the journal is about to
+ * be aborted, we can't rely on the current, or future, transactions to
+ * write out the superblock safely.
+ *
+ * We'll just use the journal_abort() error code to record an error in
+ * the journal instead.  On recovery, the journal will compain about
+ * that error until we've noted it down and cleared it.
+ */
+
+static void ext3_handle_error(struct super_block *sb)
+{
+	struct ext3_super_block *es = EXT3_SB(sb)->s_es;
+
+	EXT3_SB(sb)->s_mount_state |= EXT3_ERROR_FS;
+	es->s_state |= cpu_to_le32(EXT3_ERROR_FS);
+
+	if (sb->s_flags & MS_RDONLY)
+		return;
+
+	if (ext3_error_behaviour(sb) != EXT3_ERRORS_CONTINUE) {
+		EXT3_SB(sb)->s_mount_opt |= EXT3_MOUNT_ABORT;
+		journal_abort(EXT3_SB(sb)->s_journal, -EIO);
+	}
+
+	if (ext3_error_behaviour(sb) == EXT3_ERRORS_PANIC) 
+		panic ("EXT3-fs (device %s): panic forced after error\n",
+		       bdevname(sb->s_dev));
+
+	if (ext3_error_behaviour(sb) == EXT3_ERRORS_RO) {
+		printk (KERN_CRIT "Remounting filesystem read-only\n");
+		sb->s_flags |= MS_RDONLY;
+	}
+
+	ext3_commit_super(sb, es, 1);
+}
+
+void ext3_error (struct super_block * sb, const char * function,
+		 const char * fmt, ...)
+{
+	va_list args;
+
+	va_start (args, fmt);
+	vsprintf (error_buf, fmt, args);
+	va_end (args);
+
+	printk (KERN_CRIT "EXT3-fs error (device %s): %s: %s\n",
+		bdevname(sb->s_dev), function, error_buf);
+
+	ext3_handle_error(sb);
+}
+
+const char *ext3_decode_error(struct super_block * sb, int errno, char nbuf[16])
+{
+	char *errstr = NULL;
+	
+	switch (errno) {
+	case -EIO:
+		errstr = "IO failure";
+		break;
+	case -ENOMEM:
+		errstr = "Out of memory";
+		break;
+	case -EROFS:
+		if (!sb || EXT3_SB(sb)->s_journal->j_flags & JFS_ABORT)
+			errstr = "Journal has aborted";
+		else
+			errstr = "Readonly filesystem";
+		break;
+	default:
+		/* If the caller passed in an extra buffer for unknown
+		 * errors, textualise them now.  Else we just return
+		 * NULL. */
+		if (nbuf) {
+			/* Check for truncated error codes... */
+			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
+				errstr = nbuf;
+		}
+		
+		break;
+	}
+
+	return errstr;
+}
+
+/* __ext3_std_error decodes expected errors from journaling functions
+ * automatically and invokes the appropriate error response.  */
+
+void __ext3_std_error (struct super_block * sb, const char * function,
+		       int errno)
+{
+	char nbuf[16];
+	const char *errstr = ext3_decode_error(sb, errno, nbuf);
+
+	printk (KERN_CRIT "EXT3-fs error (device %s) in %s: %s\n",
+		bdevname(sb->s_dev), function, errstr);
+	
+	ext3_handle_error(sb);
+}
+
+/*
+ * ext3_abort is a much stronger failure handler than ext3_error.  The
+ * abort function may be used to deal with unrecoverable failures such
+ * as journal IO errors or ENOMEM at a critical moment in log management.
+ *
+ * We unconditionally force the filesystem into an ABORT|READONLY state,
+ * unless the error response on the fs has been set to panic in which
+ * case we take the easy way out and panic immediately.
+ */
+
+void ext3_abort (struct super_block * sb, const char * function,
+		 const char * fmt, ...)
+{
+	va_list args;
+
+	printk (KERN_CRIT "ext3_abort called.\n");
+
+	va_start (args, fmt);
+	vsprintf (error_buf, fmt, args);
+	va_end (args);
+
+	if (ext3_error_behaviour(sb) == EXT3_ERRORS_PANIC)
+		panic ("EXT3-fs panic (device %s): %s: %s\n",
+		       bdevname(sb->s_dev), function, error_buf);
+
+	printk (KERN_CRIT "EXT3-fs abort (device %s): %s: %s\n",
+		bdevname(sb->s_dev), function, error_buf);
+
+	if (sb->s_flags & MS_RDONLY)
+		return;
+	
+	printk (KERN_CRIT "Remounting filesystem read-only\n");
+	sb->u.ext3_sb.s_mount_state |= EXT3_ERROR_FS;
+	sb->s_flags |= MS_RDONLY;
+	sb->u.ext3_sb.s_mount_opt |= EXT3_MOUNT_ABORT;
+	journal_abort(EXT3_SB(sb)->s_journal, -EIO);
+}
+
+/* Deal with the reporting of failure conditions while running, such as
+ * inconsistencies in operation or invalid system states.
+ *
+ * Use ext3_error() for cases of invalid filesystem states, as that will
+ * record an error on disk and force a filesystem check on the next boot.
+ */
+NORET_TYPE void ext3_panic (struct super_block * sb, const char * function,
+			    const char * fmt, ...)
+{
+	va_list args;
+
+	va_start (args, fmt);
+	vsprintf (error_buf, fmt, args);
+	va_end (args);
+
+	/* this is to prevent panic from syncing this filesystem */
+	/* AKPM: is this sufficient? */
+	sb->s_flags |= MS_RDONLY;
+	panic ("EXT3-fs panic (device %s): %s: %s\n",
+	       bdevname(sb->s_dev), function, error_buf);
+}
+
+void ext3_warning (struct super_block * sb, const char * function,
+		   const char * fmt, ...)
+{
+	va_list args;
+
+	va_start (args, fmt);
+	vsprintf (error_buf, fmt, args);
+	va_end (args);
+	printk (KERN_WARNING "EXT3-fs warning (device %s): %s: %s\n",
+		bdevname(sb->s_dev), function, error_buf);
+}
+
+void ext3_update_dynamic_rev(struct super_block *sb)
+{
+	struct ext3_super_block *es = EXT3_SB(sb)->s_es;
+
+	if (le32_to_cpu(es->s_rev_level) > EXT3_GOOD_OLD_REV)
+		return;
+
+	ext3_warning(sb, __FUNCTION__,
+		     "updating to rev %d because of new feature flag, "
+		     "running e2fsck is recommended",
+		     EXT3_DYNAMIC_REV);
+
+	es->s_first_ino = cpu_to_le32(EXT3_GOOD_OLD_FIRST_INO);
+	es->s_inode_size = cpu_to_le16(EXT3_GOOD_OLD_INODE_SIZE);
+	es->s_rev_level = cpu_to_le32(EXT3_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.
+	 */
+}
+
+/*
+ * Open the external journal device
+ */
+static struct block_device *ext3_blkdev_get(kdev_t dev)
+{
+	struct block_device *bdev;
+	int err = -ENODEV;
+
+	bdev = bdget(kdev_t_to_nr(dev));
+	if (bdev == NULL)
+		goto fail;
+	err = blkdev_get(bdev, FMODE_READ|FMODE_WRITE, 0, BDEV_FS);
+	if (err < 0)
+		goto fail;
+	return bdev;
+
+fail:
+	printk(KERN_ERR "EXT3: failed to open journal device %s: %d\n",
+			bdevname(dev), err);
+	return NULL;
+}
+
+/*
+ * Release the journal device
+ */
+static int ext3_blkdev_put(struct block_device *bdev)
+{
+	return blkdev_put(bdev, BDEV_FS);
+}
+
+static int ext3_blkdev_remove(struct ext3_sb_info *sbi)
+{
+	struct block_device *bdev;
+	int ret = -ENODEV;
+
+	bdev = sbi->journal_bdev;
+	if (bdev) {
+		ret = ext3_blkdev_put(bdev);
+		sbi->journal_bdev = 0;
+	}
+	return ret;
+}
+
+#define orphan_list_entry(l) list_entry((l), struct inode, u.ext3_i.i_orphan)
+
+static void dump_orphan_list(struct super_block *sb, struct ext3_sb_info *sbi)
+{
+	struct list_head *l;
+	
+	printk(KERN_ERR "sb orphan head is %d\n", 
+	       le32_to_cpu(sbi->s_es->s_last_orphan));
+	
+	printk(KERN_ERR "sb_info orphan list:\n");
+	list_for_each(l, &sbi->s_orphan) {
+		struct inode *inode = orphan_list_entry(l);
+		printk(KERN_ERR "  "
+		       "inode 0x%04x:%ld at %p: mode %o, nlink %d, next %d\n",
+		       inode->i_dev, inode->i_ino, inode,
+		       inode->i_mode, inode->i_nlink, 
+		       le32_to_cpu(NEXT_ORPHAN(inode)));
+	}
+}
+
+void ext3_put_super (struct super_block * sb)
+{
+	struct ext3_sb_info *sbi = EXT3_SB(sb);
+	struct ext3_super_block *es = sbi->s_es;
+	kdev_t j_dev = sbi->s_journal->j_dev;
+	int i;
+
+	journal_destroy(sbi->s_journal);
+	if (!(sb->s_flags & MS_RDONLY)) {
+		EXT3_CLEAR_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_RECOVER);
+		es->s_state = le16_to_cpu(sbi->s_mount_state);
+		BUFFER_TRACE(sbi->s_sbh, "marking dirty");
+		mark_buffer_dirty(sbi->s_sbh);
+		ext3_commit_super(sb, es, 1);
+	}
+
+	for (i = 0; i < sbi->s_gdb_count; i++)
+		brelse(sbi->s_group_desc[i]);
+	kfree(sbi->s_group_desc);
+	for (i = 0; i < EXT3_MAX_GROUP_LOADED; i++)
+		brelse(sbi->s_inode_bitmap[i]);
+	for (i = 0; i < EXT3_MAX_GROUP_LOADED; i++)
+		brelse(sbi->s_block_bitmap[i]);
+	brelse(sbi->s_sbh);
+
+	/* Debugging code just in case the in-memory inode orphan list
+	 * isn't empty.  The on-disk one can be non-empty if we've
+	 * detected an error and taken the fs readonly, but the
+	 * in-memory list had better be clean by this point. */
+	if (!list_empty(&sbi->s_orphan))
+		dump_orphan_list(sb, sbi);
+	J_ASSERT(list_empty(&sbi->s_orphan));
+
+	invalidate_buffers(sb->s_dev);
+	if (j_dev != sb->s_dev) {
+		/*
+		 * Invalidate the journal device's buffers.  We don't want them
+		 * floating about in memory - the physical journal device may
+		 * hotswapped, and it breaks the `ro-after' testing code.
+		 */
+		fsync_no_super(j_dev);
+		invalidate_buffers(j_dev);
+		ext3_blkdev_remove(sbi);
+	}
+	clear_ro_after(sb);
+
+	return;
+}
+
+static struct super_operations ext3_sops = {
+	read_inode:	ext3_read_inode,	/* BKL held */
+	write_inode:	ext3_write_inode,	/* BKL not held.  Don't need */
+	dirty_inode:	ext3_dirty_inode,	/* BKL not held.  We take it */
+	put_inode:	ext3_put_inode,		/* BKL not held.  Don't need */
+	delete_inode:	ext3_delete_inode,	/* BKL not held.  We take it */
+	put_super:	ext3_put_super,		/* BKL held */
+	write_super:	ext3_write_super,	/* BKL held */
+	write_super_lockfs: ext3_write_super_lockfs, /* BKL not held. Take it */
+	unlockfs:	ext3_unlockfs,		/* BKL not held.  We take it */
+	statfs:		ext3_statfs,		/* BKL held */
+	remount_fs:	ext3_remount,		/* BKL held */
+};
+
+static int want_value(char *value, char *option)
+{
+	if (!value || !*value) {
+		printk(KERN_NOTICE "EXT3-fs: the %s option needs an argument\n",
+		       option);
+		return -1;
+	}
+	return 0;
+}
+
+static int want_null_value(char *value, char *option)
+{
+	if (*value) {
+		printk(KERN_NOTICE "EXT3-fs: Invalid %s argument: %s\n",
+		       option, value);
+		return -1;
+	}
+	return 0;
+}
+
+static int want_numeric(char *value, char *option, unsigned long *number)
+{
+	if (want_value(value, option))
+		return -1;
+	*number = simple_strtoul(value, &value, 0);
+	if (want_null_value(value, option))
+		return -1;
+	return 0;
+}
+
+/*
+ * This function has been shamelessly adapted from the msdos fs
+ */
+static int parse_options (char * options, unsigned long * sb_block,
+			  struct ext3_sb_info *sbi,
+			  unsigned long * inum,
+			  int is_remount)
+{
+	unsigned long *mount_options = &sbi->s_mount_opt;
+	uid_t *resuid = &sbi->s_resuid;
+	gid_t *resgid = &sbi->s_resgid;
+	char * this_char;
+	char * value;
+
+	if (!options)
+		return 1;
+	for (this_char = strtok (options, ",");
+	     this_char != NULL;
+	     this_char = strtok (NULL, ",")) {
+		if ((value = strchr (this_char, '=')) != NULL)
+			*value++ = 0;
+		if (!strcmp (this_char, "bsddf"))
+			clear_opt (*mount_options, MINIX_DF);
+		else if (!strcmp (this_char, "nouid32")) {
+			set_opt (*mount_options, NO_UID32);
+		}
+		else if (!strcmp (this_char, "abort"))
+			set_opt (*mount_options, ABORT);
+		else if (!strcmp (this_char, "check")) {
+			if (!value || !*value || !strcmp (value, "none"))
+				clear_opt (*mount_options, CHECK);
+			else
+#ifdef CONFIG_EXT3_CHECK
+				set_opt (*mount_options, CHECK);
+#else
+				printk(KERN_ERR 
+				       "EXT3 Check option not supported\n");
+#endif
+		}
+		else if (!strcmp (this_char, "debug"))
+			set_opt (*mount_options, DEBUG);
+		else if (!strcmp (this_char, "errors")) {
+			if (want_value(value, "errors"))
+				return 0;
+			if (!strcmp (value, "continue")) {
+				clear_opt (*mount_options, ERRORS_RO);
+				clear_opt (*mount_options, ERRORS_PANIC);
+				set_opt (*mount_options, ERRORS_CONT);
+			}
+			else if (!strcmp (value, "remount-ro")) {
+				clear_opt (*mount_options, ERRORS_CONT);
+				clear_opt (*mount_options, ERRORS_PANIC);
+				set_opt (*mount_options, ERRORS_RO);
+			}
+			else if (!strcmp (value, "panic")) {
+				clear_opt (*mount_options, ERRORS_CONT);
+				clear_opt (*mount_options, ERRORS_RO);
+				set_opt (*mount_options, ERRORS_PANIC);
+			}
+			else {
+				printk (KERN_ERR
+					"EXT3-fs: Invalid errors option: %s\n",
+					value);
+				return 0;
+			}
+		}
+		else if (!strcmp (this_char, "grpid") ||
+			 !strcmp (this_char, "bsdgroups"))
+			set_opt (*mount_options, GRPID);
+		else if (!strcmp (this_char, "minixdf"))
+			set_opt (*mount_options, MINIX_DF);
+		else if (!strcmp (this_char, "nocheck"))
+			clear_opt (*mount_options, CHECK);
+		else if (!strcmp (this_char, "nogrpid") ||
+			 !strcmp (this_char, "sysvgroups"))
+			clear_opt (*mount_options, GRPID);
+		else if (!strcmp (this_char, "resgid")) {
+			unsigned long v;
+			if (want_numeric(value, "resgid", &v))
+				return 0;
+			*resgid = v;
+		}
+		else if (!strcmp (this_char, "resuid")) {
+			unsigned long v;
+			if (want_numeric(value, "resuid", &v))
+				return 0;
+			*resuid = v;
+		}
+		else if (!strcmp (this_char, "sb")) {
+			if (want_numeric(value, "sb", sb_block))
+				return 0;
+		}
+#ifdef CONFIG_JBD_DEBUG
+		else if (!strcmp (this_char, "ro-after")) {
+			unsigned long v;
+			if (want_numeric(value, "ro-after", &v))
+				return 0;
+			ext3_ro_after = v;
+		}
+#endif
+		/* Silently ignore the quota options */
+		else if (!strcmp (this_char, "grpquota")
+		         || !strcmp (this_char, "noquota")
+		         || !strcmp (this_char, "quota")
+		         || !strcmp (this_char, "usrquota"))
+			/* Don't do anything ;-) */ ;
+		else if (!strcmp (this_char, "journal")) {
+			/* @@@ FIXME */
+			/* Eventually we will want to be able to create
+                           a journal file here.  For now, only allow the
+                           user to specify an existing inode to be the
+                           journal file. */
+			if (is_remount) {
+				printk(KERN_ERR "EXT3-fs: cannot specify "
+				       "journal on remount\n");
+				return 0;
+			}
+
+			if (want_value(value, "journal"))
+				return 0;
+			if (!strcmp (value, "update"))
+				set_opt (*mount_options, UPDATE_JOURNAL);
+			else if (want_numeric(value, "journal", inum))
+				return 0;
+		}
+		else if (!strcmp (this_char, "noload"))
+			set_opt (*mount_options, NOLOAD);
+		else if (!strcmp (this_char, "data")) {
+			int data_opt = 0;
+
+			if (want_value(value, "data"))
+				return 0;
+			if (!strcmp (value, "journal"))
+				data_opt = EXT3_MOUNT_JOURNAL_DATA;
+			else if (!strcmp (value, "ordered"))
+				data_opt = EXT3_MOUNT_ORDERED_DATA;
+			else if (!strcmp (value, "writeback"))
+				data_opt = EXT3_MOUNT_WRITEBACK_DATA;
+			else {
+				printk (KERN_ERR 
+					"EXT3-fs: Invalid data option: %s\n",
+					value);
+				return 0;
+			}
+			if (is_remount) {
+				if ((*mount_options & EXT3_MOUNT_DATA_FLAGS) !=
+							data_opt) {
+					printk(KERN_ERR
+					       "EXT3-fs: cannot change data "
+					       "mode on remount\n");
+					return 0;
+				}
+			} else {
+				*mount_options &= ~EXT3_MOUNT_DATA_FLAGS;
+				*mount_options |= data_opt;
+			}
+		} else {
+			printk (KERN_ERR 
+				"EXT3-fs: Unrecognized mount option %s\n",
+				this_char);
+			return 0;
+		}
+	}
+	return 1;
+}
+
+static int ext3_setup_super(struct super_block *sb, struct ext3_super_block *es,
+			    int read_only)
+{
+	struct ext3_sb_info *sbi = EXT3_SB(sb);
+	int res = 0;
+
+	if (le32_to_cpu(es->s_rev_level) > EXT3_MAX_SUPP_REV) {
+		printk (KERN_ERR "EXT3-fs warning: revision level too high, "
+			"forcing read-only mode\n");
+		res = MS_RDONLY;
+	}
+	if (read_only)
+		return res;
+	if (!(sbi->s_mount_state & EXT3_VALID_FS))
+		printk (KERN_WARNING "EXT3-fs warning: mounting unchecked fs, "
+			"running e2fsck is recommended\n");
+	else if ((sbi->s_mount_state & EXT3_ERROR_FS))
+		printk (KERN_WARNING
+			"EXT3-fs warning: mounting fs with errors, "
+			"running e2fsck is recommended\n");
+	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))
+		printk (KERN_WARNING
+			"EXT3-fs warning: maximal mount count reached, "
+			"running e2fsck is recommended\n");
+	else if (le32_to_cpu(es->s_checkinterval) &&
+		(le32_to_cpu(es->s_lastcheck) +
+			le32_to_cpu(es->s_checkinterval) <= CURRENT_TIME))
+		printk (KERN_WARNING
+			"EXT3-fs warning: checktime reached, "
+			"running e2fsck is recommended\n");
+#if 0
+		/* @@@ We _will_ want to clear the valid bit if we find
+                   inconsistencies, to force a fsck at reboot.  But for
+                   a plain journaled filesystem we can keep it set as
+                   valid forever! :) */
+	es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) & ~EXT3_VALID_FS);
+#endif
+	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
+		es->s_max_mnt_count =
+			(__s16) cpu_to_le16(EXT3_DFL_MAX_MNT_COUNT);
+	es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1);
+	es->s_mtime = cpu_to_le32(CURRENT_TIME);
+	ext3_update_dynamic_rev(sb);
+	EXT3_SET_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_RECOVER);
+	ext3_commit_super (sb, es, 1);
+	if (test_opt (sb, DEBUG))
+		printk (KERN_INFO
+			"[EXT3 FS %s, %s, bs=%lu, gc=%lu, "
+			"bpg=%lu, ipg=%lu, mo=%04lx]\n",
+			EXT3FS_VERSION, EXT3FS_DATE, sb->s_blocksize,
+			sbi->s_groups_count,
+			EXT3_BLOCKS_PER_GROUP(sb),
+			EXT3_INODES_PER_GROUP(sb),
+			sbi->s_mount_opt);
+	printk(KERN_INFO "EXT3 FS " EXT3FS_VERSION ", " EXT3FS_DATE " on %s, ",
+				bdevname(sb->s_dev));
+	if (EXT3_SB(sb)->s_journal->j_inode == NULL) {
+		printk("external journal on %s\n",
+				bdevname(EXT3_SB(sb)->s_journal->j_dev));
+	} else {
+		printk("internal journal\n");
+	}
+#ifdef CONFIG_EXT3_CHECK
+	if (test_opt (sb, CHECK)) {
+		ext3_check_blocks_bitmap (sb);
+		ext3_check_inodes_bitmap (sb);
+	}
+#endif
+	setup_ro_after(sb);
+	return res;
+}
+
+static int ext3_check_descriptors (struct super_block * sb)
+{
+	struct ext3_sb_info *sbi = EXT3_SB(sb);
+	unsigned long block = le32_to_cpu(sbi->s_es->s_first_data_block);
+	struct ext3_group_desc * gdp = NULL;
+	int desc_block = 0;
+	int i;
+
+	ext3_debug ("Checking group descriptors");
+
+	for (i = 0; i < sbi->s_groups_count; i++)
+	{
+		if ((i % EXT3_DESC_PER_BLOCK(sb)) == 0)
+			gdp = (struct ext3_group_desc *)
+					sbi->s_group_desc[desc_block++]->b_data;
+		if (le32_to_cpu(gdp->bg_block_bitmap) < block ||
+		    le32_to_cpu(gdp->bg_block_bitmap) >=
+				block + EXT3_BLOCKS_PER_GROUP(sb))
+		{
+			ext3_error (sb, "ext3_check_descriptors",
+				    "Block bitmap for group %d"
+				    " not in group (block %lu)!",
+				    i, (unsigned long)
+					le32_to_cpu(gdp->bg_block_bitmap));
+			return 0;
+		}
+		if (le32_to_cpu(gdp->bg_inode_bitmap) < block ||
+		    le32_to_cpu(gdp->bg_inode_bitmap) >=
+				block + EXT3_BLOCKS_PER_GROUP(sb))
+		{
+			ext3_error (sb, "ext3_check_descriptors",
+				    "Inode bitmap for group %d"
+				    " not in group (block %lu)!",
+				    i, (unsigned long)
+					le32_to_cpu(gdp->bg_inode_bitmap));
+			return 0;
+		}
+		if (le32_to_cpu(gdp->bg_inode_table) < block ||
+		    le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group >=
+		    block + EXT3_BLOCKS_PER_GROUP(sb))
+		{
+			ext3_error (sb, "ext3_check_descriptors",
+				    "Inode table for group %d"
+				    " not in group (block %lu)!",
+				    i, (unsigned long)
+					le32_to_cpu(gdp->bg_inode_table));
+			return 0;
+		}
+		block += EXT3_BLOCKS_PER_GROUP(sb);
+		gdp++;
+	}
+	return 1;
+}
+
+
+/* ext3_orphan_cleanup() walks a singly-linked list of inodes (starting at
+ * the superblock) which were deleted from all directories, but held open by
+ * a process at the time of a crash.  We walk the list and try to delete these
+ * inodes at recovery time (only with a read-write filesystem).
+ *
+ * In order to keep the orphan inode chain consistent during traversal (in
+ * case of crash during recovery), we link each inode into the superblock
+ * orphan list_head and handle it the same way as an inode deletion during
+ * normal operation (which journals the operations for us).
+ *
+ * We only do an iget() and an iput() on each inode, which is very safe if we
+ * accidentally point at an in-use or already deleted inode.  The worst that
+ * can happen in this case is that we get a "bit already cleared" message from
+ * ext3_free_inode().  The only reason we would point at a wrong inode is if
+ * e2fsck was run on this filesystem, and it must have already done the orphan
+ * inode cleanup for us, so we can safely abort without any further action.
+ */
+static void ext3_orphan_cleanup (struct super_block * sb,
+				 struct ext3_super_block * es)
+{
+	unsigned int s_flags = sb->s_flags;
+	int nr_orphans = 0, nr_truncates = 0;
+	if (!es->s_last_orphan) {
+		jbd_debug(4, "no orphan inodes to clean up\n");
+		return;
+	}
+
+	if (s_flags & MS_RDONLY) {
+		printk(KERN_INFO "EXT3-fs: %s: orphan cleanup on readonly fs\n",
+		       bdevname(sb->s_dev));
+		sb->s_flags &= ~MS_RDONLY;
+	}
+
+	if (sb->u.ext3_sb.s_mount_state & EXT3_ERROR_FS) {
+		if (es->s_last_orphan)
+			jbd_debug(1, "Errors on filesystem, "
+				  "clearing orphan list.\n");
+		es->s_last_orphan = 0;
+		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
+		return;
+	}
+
+	while (es->s_last_orphan) {
+		struct inode *inode;
+
+		if (!(inode =
+		      ext3_orphan_get(sb, le32_to_cpu(es->s_last_orphan)))) {
+			es->s_last_orphan = 0;
+			break;
+		}
+
+		list_add(&EXT3_I(inode)->i_orphan, &EXT3_SB(sb)->s_orphan);
+		if (inode->i_nlink) {
+			printk(KERN_DEBUG __FUNCTION__
+				": truncating inode %ld to %Ld bytes\n",
+				inode->i_ino, inode->i_size);
+			jbd_debug(2, "truncating inode %ld to %Ld bytes\n",
+				  inode->i_ino, inode->i_size);
+			ext3_truncate(inode);
+			nr_truncates++;
+		} else {
+			printk(KERN_DEBUG __FUNCTION__
+				": deleting unreferenced inode %ld\n",
+				inode->i_ino);
+			jbd_debug(2, "deleting unreferenced inode %ld\n",
+				  inode->i_ino);
+			nr_orphans++;
+		}
+		iput(inode);  /* The delete magic happens here! */
+	}
+
+#define PLURAL(x) (x), ((x)==1) ? "" : "s"
+
+	if (nr_orphans)
+		printk(KERN_INFO "EXT3-fs: %s: %d orphan inode%s deleted\n",
+		       bdevname(sb->s_dev), PLURAL(nr_orphans));
+	if (nr_truncates)
+		printk(KERN_INFO "EXT3-fs: %s: %d truncate%s cleaned up\n",
+		       bdevname(sb->s_dev), PLURAL(nr_truncates));
+	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
+}
+
+#define log2(n) ffz(~(n))
+
+/*
+ * 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 ext3_max_size(int bits)
+{
+	loff_t res = EXT3_NDIR_BLOCKS;
+	res += 1LL << (bits-2);
+	res += 1LL << (2*(bits-2));
+	res += 1LL << (3*(bits-2));
+	res <<= bits;
+	if (res > (512LL << 32) - (1 << bits))
+		res = (512LL << 32) - (1 << bits);
+	return res;
+}
+
+struct super_block * ext3_read_super (struct super_block * sb, void * data,
+				      int silent)
+{
+	struct buffer_head * bh;
+	struct ext3_super_block *es = 0;
+	struct ext3_sb_info *sbi = EXT3_SB(sb);
+	unsigned long sb_block = 1;
+	unsigned long logic_sb_block = 1;
+	unsigned long offset = 0;
+	unsigned long journal_inum = 0;
+	kdev_t dev = sb->s_dev;
+	int blocksize;
+	int hblock;
+	int db_count;
+	int i;
+	int needs_recovery;
+
+#ifdef CONFIG_JBD_DEBUG
+	ext3_ro_after = 0;
+#endif
+	/*
+	 * 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 = EXT3_MIN_BLOCK_SIZE;
+	hblock = get_hardsect_size(dev);
+	if (blocksize < hblock)
+		blocksize = hblock;
+
+	sbi->s_mount_opt = 0;
+	sbi->s_resuid = EXT3_DEF_RESUID;
+	sbi->s_resgid = EXT3_DEF_RESGID;
+	if (!parse_options ((char *) data, &sb_block, sbi, &journal_inum, 0)) {
+		sb->s_dev = 0;
+		goto out_fail;
+	}
+
+	set_blocksize (dev, blocksize);
+
+	/*
+	 * The ext3 superblock will not be buffer aligned for other than 1kB
+	 * block sizes.  We need to calculate the offset from buffer start.
+	 */
+	if (blocksize != EXT3_MIN_BLOCK_SIZE) {
+		logic_sb_block = (sb_block * EXT3_MIN_BLOCK_SIZE) / blocksize;
+		offset = (sb_block * EXT3_MIN_BLOCK_SIZE) % blocksize;
+	}
+
+	if (!(bh = bread (dev, logic_sb_block, blocksize))) {
+		printk (KERN_ERR "EXT3-fs: unable to read superblock\n");
+		goto out_fail;
+	}
+	/*
+	 * Note: s_es must be initialized as soon as possible because
+	 *       some ext3 macro-instructions depend on its value
+	 */
+	es = (struct ext3_super_block *) (((char *)bh->b_data) + offset);
+	sbi->s_es = es;
+	sb->s_magic = le16_to_cpu(es->s_magic);
+	if (sb->s_magic != EXT3_SUPER_MAGIC) {
+		if (!silent)
+			printk(KERN_ERR 
+			       "VFS: Can't find ext3 filesystem on dev %s.\n",
+			       bdevname(dev));
+		goto failed_mount;
+	}
+	if (le32_to_cpu(es->s_rev_level) == EXT3_GOOD_OLD_REV &&
+	    (EXT3_HAS_COMPAT_FEATURE(sb, ~0U) ||
+	     EXT3_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
+	     EXT3_HAS_INCOMPAT_FEATURE(sb, ~0U)))
+		printk(KERN_WARNING 
+		       "EXT3-fs warning: feature flags set on rev 0 fs, "
+		       "running e2fsck is recommended\n");
+	/*
+	 * 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.
+	 */
+	if ((i = EXT3_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))) {
+		printk(KERN_ERR "EXT3-fs: %s: couldn't mount because of "
+		       "unsupported optional features (%x).\n",
+		       bdevname(dev), i);
+		goto failed_mount;
+	}
+	if (!(sb->s_flags & MS_RDONLY) &&
+	    (i = EXT3_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))){
+		printk(KERN_ERR "EXT3-fs: %s: couldn't mount RDWR because of "
+		       "unsupported optional features (%x).\n",
+		       bdevname(dev), i);
+		goto failed_mount;
+	}
+	sb->s_blocksize_bits = le32_to_cpu(es->s_log_block_size) + 10;
+	sb->s_blocksize = 1 << sb->s_blocksize_bits;
+
+	if (sb->s_blocksize < EXT3_MIN_BLOCK_SIZE ||
+	    sb->s_blocksize > EXT3_MAX_BLOCK_SIZE) {
+		printk(KERN_ERR 
+		       "EXT3-fs: Unsupported filesystem blocksize %d on %s.\n",
+		       blocksize, bdevname(dev));
+		goto failed_mount;
+	}
+
+	sb->s_maxbytes = ext3_max_size(sb->s_blocksize_bits);
+
+	if (sb->s_blocksize != blocksize) {
+		blocksize = sb->s_blocksize;
+
+		/*
+		 * Make sure the blocksize for the filesystem is larger
+		 * than the hardware sectorsize for the machine.
+		 */
+		if (sb->s_blocksize < hblock) {
+			printk(KERN_ERR "EXT3-fs: blocksize %d too small for "
+			       "device blocksize %d.\n", blocksize, hblock);
+			goto failed_mount;
+		}
+
+		brelse (bh);
+		set_blocksize (dev, sb->s_blocksize);
+		logic_sb_block = (sb_block * EXT3_MIN_BLOCK_SIZE) / blocksize;
+		offset = (sb_block * EXT3_MIN_BLOCK_SIZE) % blocksize;
+		bh = bread (dev, logic_sb_block, blocksize);
+		if (!bh) {
+			printk(KERN_ERR 
+			       "EXT3-fs: Can't read superblock on 2nd try.\n");
+			return NULL;
+		}
+		es = (struct ext3_super_block *)(((char *)bh->b_data) + offset);
+		sbi->s_es = es;
+		if (es->s_magic != le16_to_cpu(EXT3_SUPER_MAGIC)) {
+			printk (KERN_ERR 
+				"EXT3-fs: Magic mismatch, very weird !\n");
+			goto failed_mount;
+		}
+	}
+
+	if (le32_to_cpu(es->s_rev_level) == EXT3_GOOD_OLD_REV) {
+		sbi->s_inode_size = EXT3_GOOD_OLD_INODE_SIZE;
+		sbi->s_first_ino = EXT3_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 != EXT3_GOOD_OLD_INODE_SIZE) {
+			printk (KERN_ERR
+				"EXT3-fs: unsupported inode size: %d\n",
+				sbi->s_inode_size);
+			goto failed_mount;
+		}
+	}
+	sbi->s_frag_size = EXT3_MIN_FRAG_SIZE <<
+				   le32_to_cpu(es->s_log_frag_size);
+	if (blocksize != sbi->s_frag_size) {
+		printk(KERN_ERR
+		       "EXT3-fs: fragsize %lu != blocksize %u (unsupported)\n",
+		       sbi->s_frag_size, blocksize);
+		goto failed_mount;
+	}
+	sbi->s_frags_per_block = 1;
+	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);
+	sbi->s_inodes_per_block = blocksize / EXT3_INODE_SIZE(sb);
+	sbi->s_itb_per_group = sbi->s_inodes_per_group /sbi->s_inodes_per_block;
+	sbi->s_desc_per_block = blocksize / sizeof(struct ext3_group_desc);
+	sbi->s_sbh = bh;
+	if (sbi->s_resuid == EXT3_DEF_RESUID)
+		sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
+	if (sbi->s_resgid == EXT3_DEF_RESGID)
+		sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
+	sbi->s_mount_state = le16_to_cpu(es->s_state);
+	sbi->s_addr_per_block_bits = log2(EXT3_ADDR_PER_BLOCK(sb));
+	sbi->s_desc_per_block_bits = log2(EXT3_DESC_PER_BLOCK(sb));
+
+	if (sbi->s_blocks_per_group > blocksize * 8) {
+		printk (KERN_ERR
+			"EXT3-fs: #blocks per group too big: %lu\n",
+			sbi->s_blocks_per_group);
+		goto failed_mount;
+	}
+	if (sbi->s_frags_per_group > blocksize * 8) {
+		printk (KERN_ERR
+			"EXT3-fs: #fragments per group too big: %lu\n",
+			sbi->s_frags_per_group);
+		goto failed_mount;
+	}
+	if (sbi->s_inodes_per_group > blocksize * 8) {
+		printk (KERN_ERR
+			"EXT3-fs: #inodes per group too big: %lu\n",
+			sbi->s_inodes_per_group);
+		goto failed_mount;
+	}
+
+	sbi->s_groups_count = (le32_to_cpu(es->s_blocks_count) -
+			       le32_to_cpu(es->s_first_data_block) +
+			       EXT3_BLOCKS_PER_GROUP(sb) - 1) /
+			      EXT3_BLOCKS_PER_GROUP(sb);
+	db_count = (sbi->s_groups_count + EXT3_DESC_PER_BLOCK(sb) - 1) /
+		   EXT3_DESC_PER_BLOCK(sb);
+	sbi->s_group_desc = kmalloc(db_count * sizeof (struct buffer_head *),
+				    GFP_KERNEL);
+	if (sbi->s_group_desc == NULL) {
+		printk (KERN_ERR "EXT3-fs: not enough memory\n");
+		goto failed_mount;
+	}
+	for (i = 0; i < db_count; i++) {
+		sbi->s_group_desc[i] = bread(dev, logic_sb_block + i + 1,
+					     blocksize);
+		if (!sbi->s_group_desc[i]) {
+			printk (KERN_ERR "EXT3-fs: "
+				"can't read group descriptor %d\n", i);
+			db_count = i;
+			goto failed_mount2;
+		}
+	}
+	if (!ext3_check_descriptors (sb)) {
+		printk (KERN_ERR "EXT3-fs: group descriptors corrupted !\n");
+		goto failed_mount2;
+	}
+	for (i = 0; i < EXT3_MAX_GROUP_LOADED; i++) {
+		sbi->s_inode_bitmap_number[i] = 0;
+		sbi->s_inode_bitmap[i] = NULL;
+		sbi->s_block_bitmap_number[i] = 0;
+		sbi->s_block_bitmap[i] = NULL;
+	}
+	sbi->s_loaded_inode_bitmaps = 0;
+	sbi->s_loaded_block_bitmaps = 0;
+	sbi->s_gdb_count = db_count;
+	/*
+	 * set up enough so that it can read an inode
+	 */
+	sb->s_op = &ext3_sops;
+	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
+
+	sb->s_root = 0;
+
+	needs_recovery = (es->s_last_orphan != 0 ||
+			  EXT3_HAS_INCOMPAT_FEATURE(sb,
+				    EXT3_FEATURE_INCOMPAT_RECOVER));
+
+	/*
+	 * The first inode we look at is the journal inode.  Don't try
+	 * root first: it may be modified in the journal!
+	 */
+	if (!test_opt(sb, NOLOAD) &&
+	    EXT3_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL)) {
+		if (ext3_load_journal(sb, es))
+			goto failed_mount2;
+	} else if (journal_inum) {
+		if (ext3_create_journal(sb, es, journal_inum))
+			goto failed_mount2;
+	} else {
+		if (!silent)
+			printk (KERN_ERR
+				"ext3: No journal on filesystem on %s\n",
+				bdevname(dev));
+		goto failed_mount2;
+	}
+
+	/* We have now updated the journal if required, so we can
+	 * validate the data journaling mode. */
+	switch (test_opt(sb, DATA_FLAGS)) {
+	case 0:
+		/* No mode set, assume a default based on the journal
+                   capabilities: ORDERED_DATA if the journal can
+                   cope, else JOURNAL_DATA */
+		if (journal_check_available_features
+		    (sbi->s_journal, 0, 0, JFS_FEATURE_INCOMPAT_REVOKE))
+			set_opt(sbi->s_mount_opt, ORDERED_DATA);
+		else
+			set_opt(sbi->s_mount_opt, JOURNAL_DATA);
+		break;
+
+	case EXT3_MOUNT_ORDERED_DATA:
+	case EXT3_MOUNT_WRITEBACK_DATA:
+		if (!journal_check_available_features
+		    (sbi->s_journal, 0, 0, JFS_FEATURE_INCOMPAT_REVOKE)) {
+			printk(KERN_ERR "EXT3-fs: Journal does not support "
+			       "requested data journaling mode\n");
+			goto failed_mount3;
+		}
+	default:
+		break;
+	}
+
+	/*
+	 * The journal_load will have done any necessary log recovery,
+	 * so we can safely mount the rest of the filesystem now.
+	 */
+
+	sb->s_root = d_alloc_root(iget(sb, EXT3_ROOT_INO));
+	if (!sb->s_root || !S_ISDIR(sb->s_root->d_inode->i_mode) ||
+	    !sb->s_root->d_inode->i_blocks || !sb->s_root->d_inode->i_size) {
+		if (sb->s_root) {
+			dput(sb->s_root);
+			sb->s_root = NULL;
+			printk(KERN_ERR
+			       "EXT3-fs: corrupt root inode, run e2fsck\n");
+		} else
+			printk(KERN_ERR "EXT3-fs: get root inode failed\n");
+		goto failed_mount3;
+	}
+
+	ext3_setup_super (sb, es, sb->s_flags & MS_RDONLY);
+	/*
+	 * akpm: core read_super() calls in here with the superblock locked.
+	 * That deadlocks, because orphan cleanup needs to lock the superblock
+	 * in numerous places.  Here we just pop the lock - it's relatively
+	 * harmless, because we are now ready to accept write_super() requests,
+	 * and aviro says that's the only reason for hanging onto the
+	 * superblock lock.
+	 */
+	EXT3_SB(sb)->s_mount_state |= EXT3_ORPHAN_FS;
+	unlock_super(sb);	/* akpm: sigh */
+	ext3_orphan_cleanup(sb, es);
+	lock_super(sb);
+	EXT3_SB(sb)->s_mount_state &= ~EXT3_ORPHAN_FS;
+	if (needs_recovery)
+		printk (KERN_INFO "EXT3-fs: recovery complete.\n");
+	ext3_mark_recovery_complete(sb, es);
+	printk (KERN_INFO "EXT3-fs: mounted filesystem with %s data mode.\n",
+		test_opt(sb,DATA_FLAGS) == EXT3_MOUNT_JOURNAL_DATA ? "journal":
+		test_opt(sb,DATA_FLAGS) == EXT3_MOUNT_ORDERED_DATA ? "ordered":
+		"writeback");
+
+	return sb;
+
+failed_mount3:
+	journal_destroy(sbi->s_journal);
+failed_mount2:
+	for (i = 0; i < db_count; i++)
+		brelse(sbi->s_group_desc[i]);
+	kfree(sbi->s_group_desc);
+failed_mount:
+	ext3_blkdev_remove(sbi);
+	brelse(bh);
+out_fail:
+	return NULL;
+}
+
+static journal_t *ext3_get_journal(struct super_block *sb, int journal_inum)
+{
+	struct inode *journal_inode;
+	journal_t *journal;
+
+	/* First, test for the existence of a valid inode on disk.  Bad
+	 * things happen if we iget() an unused inode, as the subsequent
+	 * iput() will try to delete it. */
+
+	journal_inode = iget(sb, journal_inum);
+	if (!journal_inode) {
+		printk(KERN_ERR "EXT3-fs: no journal found.\n");
+		return NULL;
+	}
+	if (!journal_inode->i_nlink) {
+		make_bad_inode(journal_inode);
+		iput(journal_inode);
+		printk(KERN_ERR "EXT3-fs: journal inode is deleted.\n");
+		return NULL;
+	}
+
+	jbd_debug(2, "Journal inode found at %p: %Ld bytes\n",
+		  journal_inode, journal_inode->i_size);
+	if (is_bad_inode(journal_inode) || !S_ISREG(journal_inode->i_mode)) {
+		printk(KERN_ERR "EXT3-fs: invalid journal inode.\n");
+		iput(journal_inode);
+		return NULL;
+	}
+
+	journal = journal_init_inode(journal_inode);
+	if (!journal)
+		iput(journal_inode);
+	return journal;
+}
+
+static journal_t *ext3_get_dev_journal(struct super_block *sb,
+				       int dev)
+{
+	struct buffer_head * bh;
+	journal_t *journal;
+	int start;
+	int len;
+	int hblock, blocksize;
+	unsigned long sb_block;
+	unsigned long offset;
+	kdev_t journal_dev = to_kdev_t(dev);
+	struct ext3_super_block * es;
+	struct block_device *bdev;
+
+	bdev = ext3_blkdev_get(journal_dev);
+	if (bdev == NULL)
+		return NULL;
+
+	blocksize = sb->s_blocksize;
+	hblock = get_hardsect_size(journal_dev);
+	if (blocksize < hblock) {
+		printk(KERN_ERR
+			"EXT3-fs: blocksize too small for journal device.\n");
+		goto out_bdev;
+	}
+	
+	sb_block = EXT3_MIN_BLOCK_SIZE / blocksize;
+	offset = EXT3_MIN_BLOCK_SIZE % blocksize;
+	set_blocksize(dev, blocksize);
+	if (!(bh = bread(dev, sb_block, blocksize))) {
+		printk(KERN_ERR "EXT3-fs: couldn't read superblock of "
+		       "external journal\n");
+		goto out_bdev;
+	}
+
+	es = (struct ext3_super_block *) (((char *)bh->b_data) + offset);
+	if ((le16_to_cpu(es->s_magic) != EXT3_SUPER_MAGIC) ||
+	    !(le32_to_cpu(es->s_feature_incompat) &
+	      EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)) {
+		printk(KERN_ERR "EXT3-fs: external journal has "
+					"bad superblock\n");
+		brelse(bh);
+		goto out_bdev;
+	}
+
+	if (memcmp(EXT3_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
+		printk(KERN_ERR "EXT3-fs: journal UUID does not match\n");
+		brelse(bh);
+		goto out_bdev;
+	}
+
+	len = le32_to_cpu(es->s_blocks_count);
+	start = sb_block + 1;
+	brelse(bh);	/* we're done with the superblock */
+
+	journal = journal_init_dev(journal_dev, sb->s_dev, 
+					start, len, blocksize);
+	if (!journal) {
+		printk(KERN_ERR "EXT3-fs: failed to create device journal\n");
+		goto out_bdev;
+	}
+	ll_rw_block(READ, 1, &journal->j_sb_buffer);
+	wait_on_buffer(journal->j_sb_buffer);
+	if (!buffer_uptodate(journal->j_sb_buffer)) {
+		printk(KERN_ERR "EXT3-fs: I/O error on journal device\n");
+		goto out_journal;
+	}
+	if (ntohl(journal->j_superblock->s_nr_users) != 1) {
+		printk(KERN_ERR "EXT3-fs: External journal has more than one "
+					"user (unsupported) - %d\n",
+			ntohl(journal->j_superblock->s_nr_users));
+		goto out_journal;
+	}
+	EXT3_SB(sb)->journal_bdev = bdev;
+	return journal;
+out_journal:
+	journal_destroy(journal);
+out_bdev:
+	ext3_blkdev_put(bdev);
+	return NULL;
+}
+
+static int ext3_load_journal(struct super_block * sb,
+			     struct ext3_super_block * es)
+{
+	journal_t *journal;
+	int journal_inum = le32_to_cpu(es->s_journal_inum);
+	int journal_dev = le32_to_cpu(es->s_journal_dev);
+	int err;
+	int really_read_only;
+
+	really_read_only = is_read_only(sb->s_dev);
+
+	/*
+	 * Are we loading a blank journal or performing recovery after a
+	 * crash?  For recovery, we need to check in advance whether we
+	 * can get read-write access to the device.
+	 */
+
+	if (EXT3_HAS_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_RECOVER)) {
+		if (sb->s_flags & MS_RDONLY) {
+			printk(KERN_INFO "EXT3-fs: INFO: recovery "
+					"required on readonly filesystem.\n");
+			if (really_read_only) {
+				printk(KERN_ERR "EXT3-fs: write access "
+					"unavailable, cannot proceed.\n");
+				return -EROFS;
+			}
+			printk (KERN_INFO "EXT3-fs: write access will "
+					"be enabled during recovery.\n");
+		}
+	}
+
+	if (journal_inum && journal_dev) {
+		printk(KERN_ERR "EXT3-fs: filesystem has both journal "
+		       "and inode journals!\n");
+		return -EINVAL;
+	}
+
+	if (journal_inum) {
+		if (!(journal = ext3_get_journal(sb, journal_inum)))
+			return -EINVAL;
+	} else {
+		if (!(journal = ext3_get_dev_journal(sb, journal_dev)))
+			return -EINVAL;
+	}
+	
+
+	if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
+		err = journal_update_format(journal);
+		if (err)  {
+			printk(KERN_ERR "EXT3-fs: error updating journal.\n");
+			journal_destroy(journal);
+			return err;
+		}
+	}
+
+	if (!EXT3_HAS_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_RECOVER))
+		journal_wipe(journal, !really_read_only);
+
+	err = journal_load(journal);
+	if (err) {
+		printk(KERN_ERR "EXT3-fs: error loading journal.\n");
+		journal_destroy(journal);
+		return err;
+	}
+
+	EXT3_SB(sb)->s_journal = journal;
+	ext3_clear_journal_err(sb, es);
+	return 0;
+}
+
+static int ext3_create_journal(struct super_block * sb,
+			       struct ext3_super_block * es,
+			       int journal_inum)
+{
+	journal_t *journal;
+
+	if (sb->s_flags & MS_RDONLY) {
+		printk(KERN_ERR "EXT3-fs: readonly filesystem when trying to "
+				"create journal.\n");
+		return -EROFS;
+	}
+
+	if (!(journal = ext3_get_journal(sb, journal_inum)))
+		return -EINVAL;
+
+	printk(KERN_INFO "EXT3-fs: creating new journal on inode %d\n",
+	       journal_inum);
+
+	if (journal_create(journal)) {
+		printk(KERN_ERR "EXT3-fs: error creating journal.\n");
+		journal_destroy(journal);
+		return -EIO;
+	}
+
+	EXT3_SB(sb)->s_journal = journal;
+
+	ext3_update_dynamic_rev(sb);
+	EXT3_SET_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_RECOVER);
+	EXT3_SET_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL);
+
+	es->s_journal_inum = cpu_to_le32(journal_inum);
+	sb->s_dirt = 1;
+
+	/* Make sure we flush the recovery flag to disk. */
+	ext3_commit_super(sb, es, 1);
+
+	return 0;
+}
+
+static void ext3_commit_super (struct super_block * sb,
+			       struct ext3_super_block * es,
+			       int sync)
+{
+	es->s_wtime = cpu_to_le32(CURRENT_TIME);
+	BUFFER_TRACE(sb->u.ext3_sb.s_sbh, "marking dirty");
+	mark_buffer_dirty(sb->u.ext3_sb.s_sbh);
+	if (sync) {
+		ll_rw_block(WRITE, 1, &sb->u.ext3_sb.s_sbh);
+		wait_on_buffer(sb->u.ext3_sb.s_sbh);
+	}
+}
+
+
+/*
+ * Have we just finished recovery?  If so, and if we are mounting (or
+ * remounting) the filesystem readonly, then we will end up with a
+ * consistent fs on disk.  Record that fact.
+ */
+static void ext3_mark_recovery_complete(struct super_block * sb,
+					struct ext3_super_block * es)
+{
+	journal_flush(EXT3_SB(sb)->s_journal);
+	if (EXT3_HAS_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_RECOVER) &&
+	    sb->s_flags & MS_RDONLY) {
+		EXT3_CLEAR_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_RECOVER);
+		sb->s_dirt = 0;
+		ext3_commit_super(sb, es, 1);
+	}
+}
+
+/*
+ * If we are mounting (or read-write remounting) a filesystem whose journal
+ * has recorded an error from a previous lifetime, move that error to the
+ * main filesystem now.
+ */
+static void ext3_clear_journal_err(struct super_block * sb,
+				   struct ext3_super_block * es)
+{
+	journal_t *journal;
+	int j_errno;
+	const char *errstr;
+	
+	journal = EXT3_SB(sb)->s_journal;
+
+	/*
+	 * Now check for any error status which may have been recorded in the
+	 * journal by a prior ext3_error() or ext3_abort()
+	 */
+
+	j_errno = journal_errno(journal);
+	if (j_errno) {
+		char nbuf[16];
+		
+		errstr = ext3_decode_error(sb, j_errno, nbuf);
+		ext3_warning(sb, __FUNCTION__, "Filesystem error recorded "
+			     "from previous mount: %s", errstr);
+		ext3_warning(sb, __FUNCTION__, "Marking fs in need of "
+			     "filesystem check.");
+		
+		sb->u.ext3_sb.s_mount_state |= EXT3_ERROR_FS;
+		es->s_state |= cpu_to_le16(EXT3_ERROR_FS);
+		ext3_commit_super (sb, es, 1);
+
+		journal_clear_err(journal);
+	}
+}
+
+/*
+ * Force the running and committing transactions to commit,
+ * and wait on the commit.
+ */
+int ext3_force_commit(struct super_block *sb)
+{
+	journal_t *journal;
+	int ret;
+
+	if (sb->s_flags & MS_RDONLY)
+		return 0;
+
+	journal = EXT3_SB(sb)->s_journal;
+	sb->s_dirt = 0;
+	lock_kernel();	/* important: lock down j_running_transaction */
+	ret = ext3_journal_force_commit(journal);
+	unlock_kernel();
+	return ret;
+}
+
+/*
+ * Ext3 always journals updates to the superblock itself, so we don't
+ * have to propagate any other updates to the superblock on disk at this
+ * point.  Just start an async writeback to get the buffers on their way
+ * to the disk.
+ *
+ * This implicitly triggers the writebehind on sync().
+ */
+
+static int do_sync_supers = 0;
+MODULE_PARM(do_sync_supers, "i");
+MODULE_PARM_DESC(do_sync_supers, "Write superblocks synchronously");
+
+void ext3_write_super (struct super_block * sb)
+{
+	tid_t target;
+	
+	if (down_trylock(&sb->s_lock) == 0)
+		BUG();		/* aviro detector */
+	sb->s_dirt = 0;
+	target = log_start_commit(EXT3_SB(sb)->s_journal, NULL);
+
+	if (do_sync_supers) {
+		unlock_super(sb);
+		log_wait_commit(EXT3_SB(sb)->s_journal, target);
+		lock_super(sb);
+	}
+}
+
+/*
+ * LVM calls this function before a (read-only) snapshot is created.  This
+ * gives us a chance to flush the journal completely and mark the fs clean.
+ */
+void ext3_write_super_lockfs(struct super_block *sb)
+{
+	sb->s_dirt = 0;
+
+	lock_kernel();		/* 2.4.5 forgot to do this for us */
+	if (!(sb->s_flags & MS_RDONLY)) {
+		journal_t *journal = EXT3_SB(sb)->s_journal;
+
+		/* Now we set up the journal barrier. */
+		journal_lock_updates(journal);
+		journal_flush(journal);
+
+		/* Journal blocked and flushed, clear needs_recovery flag. */
+		EXT3_CLEAR_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_RECOVER);
+		ext3_commit_super(sb, EXT3_SB(sb)->s_es, 1);
+	}
+	unlock_kernel();
+}
+
+/*
+ * Called by LVM after the snapshot is done.  We need to reset the RECOVER
+ * flag here, even though the filesystem is not technically dirty yet.
+ */
+void ext3_unlockfs(struct super_block *sb)
+{
+	if (!(sb->s_flags & MS_RDONLY)) {
+		lock_kernel();
+		lock_super(sb);
+		/* Reser the needs_recovery flag before the fs is unlocked. */
+		EXT3_SET_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_RECOVER);
+		ext3_commit_super(sb, EXT3_SB(sb)->s_es, 1);
+		unlock_super(sb);
+		journal_unlock_updates(EXT3_SB(sb)->s_journal);
+		unlock_kernel();
+	}
+}
+
+int ext3_remount (struct super_block * sb, int * flags, char * data)
+{
+	struct ext3_super_block * es;
+	struct ext3_sb_info *sbi = EXT3_SB(sb);
+	unsigned long tmp;
+
+	clear_ro_after(sb);
+
+	/*
+	 * Allow the "check" option to be passed as a remount option.
+	 */
+	if (!parse_options(data, &tmp, sbi, &tmp, 1))
+		return -EINVAL;
+
+	if (sbi->s_mount_opt & EXT3_MOUNT_ABORT)
+		ext3_abort(sb, __FUNCTION__, "Abort forced by user");
+
+	es = sbi->s_es;
+
+	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
+		if (sbi->s_mount_opt & EXT3_MOUNT_ABORT)
+			return -EROFS;
+
+		if (*flags & MS_RDONLY) {
+			/*
+			 * First of all, the unconditional stuff we have to do
+			 * to disable replay of the journal when we next remount
+			 */
+			sb->s_flags |= MS_RDONLY;
+
+			/*
+			 * OK, test if we are remounting a valid rw partition
+			 * readonly, and if so set the rdonly flag and then
+			 * mark the partition as valid again.
+			 */
+			if (!(es->s_state & cpu_to_le16(EXT3_VALID_FS)) &&
+			    (sbi->s_mount_state & EXT3_VALID_FS))
+				es->s_state = cpu_to_le16(sbi->s_mount_state);
+
+			ext3_mark_recovery_complete(sb, es);
+		} else {
+			int ret;
+			if ((ret = EXT3_HAS_RO_COMPAT_FEATURE(sb,
+					~EXT3_FEATURE_RO_COMPAT_SUPP))) {
+				printk(KERN_WARNING "EXT3-fs: %s: couldn't "
+				       "remount RDWR because of unsupported "
+				       "optional features (%x).\n",
+				       bdevname(sb->s_dev), ret);
+				return -EROFS;
+			}
+			/*
+			 * 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.)
+			 */
+			ext3_clear_journal_err(sb, es);
+			sbi->s_mount_state = le16_to_cpu(es->s_state);
+			if (!ext3_setup_super (sb, es, 0))
+				sb->s_flags &= ~MS_RDONLY;
+		}
+	}
+	setup_ro_after(sb);
+	return 0;
+}
+
+int ext3_statfs (struct super_block * sb, struct statfs * buf)
+{
+	struct ext3_super_block *es = EXT3_SB(sb)->s_es;
+	unsigned long overhead;
+	int i;
+
+	if (test_opt (sb, MINIX_DF))
+		overhead = 0;
+	else {
+		/*
+		 * Compute the overhead (FS structures)
+		 */
+
+		/*
+		 * All of the blocks before first_data_block are
+		 * overhead
+		 */
+		overhead = le32_to_cpu(es->s_first_data_block);
+
+		/*
+		 * 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 < EXT3_SB(sb)->s_groups_count; i++)
+			overhead += ext3_bg_has_super(sb, i) +
+				ext3_bg_num_gdb(sb, i);
+
+		/*
+		 * Every block group has an inode bitmap, a block
+		 * bitmap, and an inode table.
+		 */
+		overhead += (EXT3_SB(sb)->s_groups_count *
+			     (2 + EXT3_SB(sb)->s_itb_per_group));
+	}
+
+	buf->f_type = EXT3_SUPER_MAGIC;
+	buf->f_bsize = sb->s_blocksize;
+	buf->f_blocks = le32_to_cpu(es->s_blocks_count) - overhead;
+	buf->f_bfree = ext3_count_free_blocks (sb);
+	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))
+		buf->f_bavail = 0;
+	buf->f_files = le32_to_cpu(es->s_inodes_count);
+	buf->f_ffree = ext3_count_free_inodes (sb);
+	buf->f_namelen = EXT3_NAME_LEN;
+	return 0;
+}
+
+static DECLARE_FSTYPE_DEV(ext3_fs_type, "ext3", ext3_read_super);
+
+static int __init init_ext3_fs(void)
+{
+        return register_filesystem(&ext3_fs_type);
+}
+
+static void __exit exit_ext3_fs(void)
+{
+	unregister_filesystem(&ext3_fs_type);
+}
+
+EXPORT_NO_SYMBOLS;
+
+MODULE_LICENSE("GPL");
+module_init(init_ext3_fs)
+module_exit(exit_ext3_fs)

FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)