X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=fs%2Fext4%2Fsuper.c;h=7d865608e8175f2d9ed323517306c36e42b88ba4;hb=39d80c33a068d9fa63a36c3b2c0d718d38440dd1;hp=1e69f29a8c5582ba209ad7dbeb49e57396d7e2fe;hpb=9a5467fd600669cda488771dac3e951034fe2b08;p=linux-2.6-omap-h63xx.git

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 1e69f29a8c5..7d865608e81 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -34,6 +34,8 @@
 #include <linux/namei.h>
 #include <linux/quotaops.h>
 #include <linux/seq_file.h>
+#include <linux/proc_fs.h>
+#include <linux/marker.h>
 #include <linux/log2.h>
 #include <linux/crc16.h>
 #include <asm/uaccess.h>
@@ -45,24 +47,25 @@
 #include "namei.h"
 #include "group.h"
 
+struct proc_dir_entry *ext4_proc_root;
+
 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
 			     unsigned long journal_devnum);
 static int ext4_create_journal(struct super_block *, struct ext4_super_block *,
 			       unsigned int);
-static void ext4_commit_super (struct super_block * sb,
-			       struct ext4_super_block * es,
-			       int sync);
-static void ext4_mark_recovery_complete(struct super_block * sb,
-					struct ext4_super_block * es);
-static void ext4_clear_journal_err(struct super_block * sb,
-				   struct ext4_super_block * es);
+static void ext4_commit_super(struct super_block *sb,
+			      struct ext4_super_block *es, int sync);
+static void ext4_mark_recovery_complete(struct super_block *sb,
+					struct ext4_super_block *es);
+static void ext4_clear_journal_err(struct super_block *sb,
+				   struct ext4_super_block *es);
 static int ext4_sync_fs(struct super_block *sb, int wait);
-static const char *ext4_decode_error(struct super_block * sb, int errno,
+static const char *ext4_decode_error(struct super_block *sb, int errno,
 				     char nbuf[16]);
-static int ext4_remount (struct super_block * sb, int * flags, char * data);
-static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf);
+static int ext4_remount(struct super_block *sb, int *flags, char *data);
+static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
 static void ext4_unlockfs(struct super_block *sb);
-static void ext4_write_super (struct super_block * sb);
+static void ext4_write_super(struct super_block *sb);
 static void ext4_write_super_lockfs(struct super_block *sb);
 
 
@@ -211,15 +214,15 @@ static void ext4_handle_error(struct super_block *sb)
 	if (sb->s_flags & MS_RDONLY)
 		return;
 
-	if (!test_opt (sb, ERRORS_CONT)) {
+	if (!test_opt(sb, ERRORS_CONT)) {
 		journal_t *journal = EXT4_SB(sb)->s_journal;
 
 		EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
 		if (journal)
 			jbd2_journal_abort(journal, -EIO);
 	}
-	if (test_opt (sb, ERRORS_RO)) {
-		printk (KERN_CRIT "Remounting filesystem read-only\n");
+	if (test_opt(sb, ERRORS_RO)) {
+		printk(KERN_CRIT "Remounting filesystem read-only\n");
 		sb->s_flags |= MS_RDONLY;
 	}
 	ext4_commit_super(sb, es, 1);
@@ -228,13 +231,13 @@ static void ext4_handle_error(struct super_block *sb)
 			sb->s_id);
 }
 
-void ext4_error (struct super_block * sb, const char * function,
-		 const char * fmt, ...)
+void ext4_error(struct super_block *sb, const char *function,
+		const char *fmt, ...)
 {
 	va_list args;
 
 	va_start(args, fmt);
-	printk(KERN_CRIT "EXT4-fs error (device %s): %s: ",sb->s_id, function);
+	printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
 	vprintk(fmt, args);
 	printk("\n");
 	va_end(args);
@@ -242,7 +245,7 @@ void ext4_error (struct super_block * sb, const char * function,
 	ext4_handle_error(sb);
 }
 
-static const char *ext4_decode_error(struct super_block * sb, int errno,
+static const char *ext4_decode_error(struct super_block *sb, int errno,
 				     char nbuf[16])
 {
 	char *errstr = NULL;
@@ -278,8 +281,7 @@ static const char *ext4_decode_error(struct super_block * sb, int errno,
 /* __ext4_std_error decodes expected errors from journaling functions
  * automatically and invokes the appropriate error response.  */
 
-void __ext4_std_error (struct super_block * sb, const char * function,
-		       int errno)
+void __ext4_std_error(struct super_block *sb, const char *function, int errno)
 {
 	char nbuf[16];
 	const char *errstr;
@@ -292,8 +294,8 @@ void __ext4_std_error (struct super_block * sb, const char * function,
 		return;
 
 	errstr = ext4_decode_error(sb, errno, nbuf);
-	printk (KERN_CRIT "EXT4-fs error (device %s) in %s: %s\n",
-		sb->s_id, function, errstr);
+	printk(KERN_CRIT "EXT4-fs error (device %s) in %s: %s\n",
+	       sb->s_id, function, errstr);
 
 	ext4_handle_error(sb);
 }
@@ -308,15 +310,15 @@ void __ext4_std_error (struct super_block * sb, const char * function,
  * case we take the easy way out and panic immediately.
  */
 
-void ext4_abort (struct super_block * sb, const char * function,
-		 const char * fmt, ...)
+void ext4_abort(struct super_block *sb, const char *function,
+		const char *fmt, ...)
 {
 	va_list args;
 
-	printk (KERN_CRIT "ext4_abort called.\n");
+	printk(KERN_CRIT "ext4_abort called.\n");
 
 	va_start(args, fmt);
-	printk(KERN_CRIT "EXT4-fs error (device %s): %s: ",sb->s_id, function);
+	printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
 	vprintk(fmt, args);
 	printk("\n");
 	va_end(args);
@@ -334,8 +336,8 @@ void ext4_abort (struct super_block * sb, const char * function,
 	jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 }
 
-void ext4_warning (struct super_block * sb, const char * function,
-		   const char * fmt, ...)
+void ext4_warning(struct super_block *sb, const char *function,
+		  const char *fmt, ...)
 {
 	va_list args;
 
@@ -496,7 +498,7 @@ static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 	}
 }
 
-static void ext4_put_super (struct super_block * sb)
+static void ext4_put_super(struct super_block *sb)
 {
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
 	struct ext4_super_block *es = sbi->s_es;
@@ -510,10 +512,12 @@ static void ext4_put_super (struct super_block * sb)
 	if (!(sb->s_flags & MS_RDONLY)) {
 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 		es->s_state = cpu_to_le16(sbi->s_mount_state);
-		BUFFER_TRACE(sbi->s_sbh, "marking dirty");
-		mark_buffer_dirty(sbi->s_sbh);
 		ext4_commit_super(sb, es, 1);
 	}
+	if (sbi->s_proc) {
+		remove_proc_entry("inode_readahead_blks", sbi->s_proc);
+		remove_proc_entry(sb->s_id, ext4_proc_root);
+	}
 
 	for (i = 0; i < sbi->s_gdb_count; i++)
 		brelse(sbi->s_group_desc[i]);
@@ -522,6 +526,7 @@ static void ext4_put_super (struct super_block * sb)
 	percpu_counter_destroy(&sbi->s_freeblocks_counter);
 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
 	percpu_counter_destroy(&sbi->s_dirs_counter);
+	percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
 	brelse(sbi->s_sbh);
 #ifdef CONFIG_QUOTA
 	for (i = 0; i < MAXQUOTAS; i++)
@@ -568,8 +573,8 @@ static struct inode *ext4_alloc_inode(struct super_block *sb)
 	ei->i_acl = EXT4_ACL_NOT_CACHED;
 	ei->i_default_acl = EXT4_ACL_NOT_CACHED;
 #endif
-	ei->i_block_alloc_info = NULL;
 	ei->vfs_inode.i_version = 1;
+	ei->vfs_inode.i_data.writeback_index = 0;
 	memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
 	INIT_LIST_HEAD(&ei->i_prealloc_list);
 	spin_lock_init(&ei->i_prealloc_lock);
@@ -626,7 +631,6 @@ static void destroy_inodecache(void)
 
 static void ext4_clear_inode(struct inode *inode)
 {
-	struct ext4_block_alloc_info *rsv = EXT4_I(inode)->i_block_alloc_info;
 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
 	if (EXT4_I(inode)->i_acl &&
 			EXT4_I(inode)->i_acl != EXT4_ACL_NOT_CACHED) {
@@ -639,22 +643,20 @@ static void ext4_clear_inode(struct inode *inode)
 		EXT4_I(inode)->i_default_acl = EXT4_ACL_NOT_CACHED;
 	}
 #endif
-	ext4_discard_reservation(inode);
-	EXT4_I(inode)->i_block_alloc_info = NULL;
-	if (unlikely(rsv))
-		kfree(rsv);
+	ext4_discard_preallocations(inode);
 	jbd2_journal_release_jbd_inode(EXT4_SB(inode->i_sb)->s_journal,
 				       &EXT4_I(inode)->jinode);
 }
 
-static inline void ext4_show_quota_options(struct seq_file *seq, struct super_block *sb)
+static inline void ext4_show_quota_options(struct seq_file *seq,
+					   struct super_block *sb)
 {
 #if defined(CONFIG_QUOTA)
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
 
 	if (sbi->s_jquota_fmt)
 		seq_printf(seq, ",jqfmt=%s",
-		(sbi->s_jquota_fmt == QFMT_VFS_OLD) ? "vfsold": "vfsv0");
+		(sbi->s_jquota_fmt == QFMT_VFS_OLD) ? "vfsold" : "vfsv0");
 
 	if (sbi->s_qf_names[USRQUOTA])
 		seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
@@ -752,8 +754,6 @@ static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
 		seq_puts(seq, ",nobh");
 	if (!test_opt(sb, EXTENTS))
 		seq_puts(seq, ",noextents");
-	if (!test_opt(sb, MBALLOC))
-		seq_puts(seq, ",nomballoc");
 	if (test_opt(sb, I_VERSION))
 		seq_puts(seq, ",i_version");
 	if (!test_opt(sb, DELALLOC))
@@ -773,6 +773,10 @@ static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
 	else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
 		seq_puts(seq, ",data=writeback");
 
+	if (sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
+		seq_printf(seq, ",inode_readahead_blks=%u",
+			   sbi->s_inode_readahead_blks);
+
 	ext4_show_quota_options(seq, sb);
 	return 0;
 }
@@ -822,8 +826,8 @@ static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
 }
 
 #ifdef CONFIG_QUOTA
-#define QTYPE2NAME(t) ((t)==USRQUOTA?"user":"group")
-#define QTYPE2MOPT(on, t) ((t)==USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
+#define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
+#define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
 
 static int ext4_dquot_initialize(struct inode *inode, int type);
 static int ext4_dquot_drop(struct inode *inode);
@@ -907,6 +911,7 @@ enum {
 	Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota,
 	Opt_grpquota, Opt_extents, Opt_noextents, Opt_i_version,
 	Opt_mballoc, Opt_nomballoc, Opt_stripe, Opt_delalloc, Opt_nodelalloc,
+	Opt_inode_readahead_blks
 };
 
 static match_table_t tokens = {
@@ -967,6 +972,7 @@ static match_table_t tokens = {
 	{Opt_resize, "resize"},
 	{Opt_delalloc, "delalloc"},
 	{Opt_nodelalloc, "nodelalloc"},
+	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
 	{Opt_err, NULL},
 };
 
@@ -981,7 +987,7 @@ static ext4_fsblk_t get_sb_block(void **data)
 	/*todo: use simple_strtoll with >32bit ext4 */
 	sb_block = simple_strtoul(options, &options, 0);
 	if (*options && *options != ',') {
-		printk("EXT4-fs: Invalid sb specification: %s\n",
+		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
 		       (char *) *data);
 		return 1;
 	}
@@ -991,12 +997,12 @@ static ext4_fsblk_t get_sb_block(void **data)
 	return sb_block;
 }
 
-static int parse_options (char *options, struct super_block *sb,
-			  unsigned int *inum, unsigned long *journal_devnum,
-			  ext4_fsblk_t *n_blocks_count, int is_remount)
+static int parse_options(char *options, struct super_block *sb,
+			 unsigned int *inum, unsigned long *journal_devnum,
+			 ext4_fsblk_t *n_blocks_count, int is_remount)
 {
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
-	char * p;
+	char *p;
 	substring_t args[MAX_OPT_ARGS];
 	int data_opt = 0;
 	int option;
@@ -1009,7 +1015,7 @@ static int parse_options (char *options, struct super_block *sb,
 	if (!options)
 		return 1;
 
-	while ((p = strsep (&options, ",")) != NULL) {
+	while ((p = strsep(&options, ",")) != NULL) {
 		int token;
 		if (!*p)
 			continue;
@@ -1017,16 +1023,16 @@ static int parse_options (char *options, struct super_block *sb,
 		token = match_token(p, tokens, args);
 		switch (token) {
 		case Opt_bsd_df:
-			clear_opt (sbi->s_mount_opt, MINIX_DF);
+			clear_opt(sbi->s_mount_opt, MINIX_DF);
 			break;
 		case Opt_minix_df:
-			set_opt (sbi->s_mount_opt, MINIX_DF);
+			set_opt(sbi->s_mount_opt, MINIX_DF);
 			break;
 		case Opt_grpid:
-			set_opt (sbi->s_mount_opt, GRPID);
+			set_opt(sbi->s_mount_opt, GRPID);
 			break;
 		case Opt_nogrpid:
-			clear_opt (sbi->s_mount_opt, GRPID);
+			clear_opt(sbi->s_mount_opt, GRPID);
 			break;
 		case Opt_resuid:
 			if (match_int(&args[0], &option))
@@ -1043,46 +1049,47 @@ static int parse_options (char *options, struct super_block *sb,
 			/* *sb_block = match_int(&args[0]); */
 			break;
 		case Opt_err_panic:
-			clear_opt (sbi->s_mount_opt, ERRORS_CONT);
-			clear_opt (sbi->s_mount_opt, ERRORS_RO);
-			set_opt (sbi->s_mount_opt, ERRORS_PANIC);
+			clear_opt(sbi->s_mount_opt, ERRORS_CONT);
+			clear_opt(sbi->s_mount_opt, ERRORS_RO);
+			set_opt(sbi->s_mount_opt, ERRORS_PANIC);
 			break;
 		case Opt_err_ro:
-			clear_opt (sbi->s_mount_opt, ERRORS_CONT);
-			clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
-			set_opt (sbi->s_mount_opt, ERRORS_RO);
+			clear_opt(sbi->s_mount_opt, ERRORS_CONT);
+			clear_opt(sbi->s_mount_opt, ERRORS_PANIC);
+			set_opt(sbi->s_mount_opt, ERRORS_RO);
 			break;
 		case Opt_err_cont:
-			clear_opt (sbi->s_mount_opt, ERRORS_RO);
-			clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
-			set_opt (sbi->s_mount_opt, ERRORS_CONT);
+			clear_opt(sbi->s_mount_opt, ERRORS_RO);
+			clear_opt(sbi->s_mount_opt, ERRORS_PANIC);
+			set_opt(sbi->s_mount_opt, ERRORS_CONT);
 			break;
 		case Opt_nouid32:
-			set_opt (sbi->s_mount_opt, NO_UID32);
+			set_opt(sbi->s_mount_opt, NO_UID32);
 			break;
 		case Opt_nocheck:
-			clear_opt (sbi->s_mount_opt, CHECK);
+			clear_opt(sbi->s_mount_opt, CHECK);
 			break;
 		case Opt_debug:
-			set_opt (sbi->s_mount_opt, DEBUG);
+			set_opt(sbi->s_mount_opt, DEBUG);
 			break;
 		case Opt_oldalloc:
-			set_opt (sbi->s_mount_opt, OLDALLOC);
+			set_opt(sbi->s_mount_opt, OLDALLOC);
 			break;
 		case Opt_orlov:
-			clear_opt (sbi->s_mount_opt, OLDALLOC);
+			clear_opt(sbi->s_mount_opt, OLDALLOC);
 			break;
 #ifdef CONFIG_EXT4DEV_FS_XATTR
 		case Opt_user_xattr:
-			set_opt (sbi->s_mount_opt, XATTR_USER);
+			set_opt(sbi->s_mount_opt, XATTR_USER);
 			break;
 		case Opt_nouser_xattr:
-			clear_opt (sbi->s_mount_opt, XATTR_USER);
+			clear_opt(sbi->s_mount_opt, XATTR_USER);
 			break;
 #else
 		case Opt_user_xattr:
 		case Opt_nouser_xattr:
-			printk("EXT4 (no)user_xattr options not supported\n");
+			printk(KERN_ERR "EXT4 (no)user_xattr options "
+			       "not supported\n");
 			break;
 #endif
 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
@@ -1095,7 +1102,8 @@ static int parse_options (char *options, struct super_block *sb,
 #else
 		case Opt_acl:
 		case Opt_noacl:
-			printk("EXT4 (no)acl options not supported\n");
+			printk(KERN_ERR "EXT4 (no)acl options "
+			       "not supported\n");
 			break;
 #endif
 		case Opt_reservation:
@@ -1115,7 +1123,7 @@ static int parse_options (char *options, struct super_block *sb,
 				       "journal on remount\n");
 				return 0;
 			}
-			set_opt (sbi->s_mount_opt, UPDATE_JOURNAL);
+			set_opt(sbi->s_mount_opt, UPDATE_JOURNAL);
 			break;
 		case Opt_journal_inum:
 			if (is_remount) {
@@ -1145,7 +1153,7 @@ static int parse_options (char *options, struct super_block *sb,
 			set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
 			break;
 		case Opt_noload:
-			set_opt (sbi->s_mount_opt, NOLOAD);
+			set_opt(sbi->s_mount_opt, NOLOAD);
 			break;
 		case Opt_commit:
 			if (match_int(&args[0], &option))
@@ -1189,8 +1197,8 @@ set_qf_name:
 			     sb_any_quota_suspended(sb)) &&
 			    !sbi->s_qf_names[qtype]) {
 				printk(KERN_ERR
-					"EXT4-fs: Cannot change journaled "
-					"quota options when quota turned on.\n");
+				       "EXT4-fs: Cannot change journaled "
+				       "quota options when quota turned on.\n");
 				return 0;
 			}
 			qname = match_strdup(&args[0]);
@@ -1331,7 +1339,7 @@ set_qf_format:
 					"on this filesystem, use tune2fs\n");
 				return 0;
 			}
-			set_opt (sbi->s_mount_opt, EXTENTS);
+			set_opt(sbi->s_mount_opt, EXTENTS);
 			break;
 		case Opt_noextents:
 			/*
@@ -1348,7 +1356,7 @@ set_qf_format:
 						"-o noextents options\n");
 				return 0;
 			}
-			clear_opt (sbi->s_mount_opt, EXTENTS);
+			clear_opt(sbi->s_mount_opt, EXTENTS);
 			break;
 		case Opt_i_version:
 			set_opt(sbi->s_mount_opt, I_VERSION);
@@ -1357,12 +1365,6 @@ set_qf_format:
 		case Opt_nodelalloc:
 			clear_opt(sbi->s_mount_opt, DELALLOC);
 			break;
-		case Opt_mballoc:
-			set_opt(sbi->s_mount_opt, MBALLOC);
-			break;
-		case Opt_nomballoc:
-			clear_opt(sbi->s_mount_opt, MBALLOC);
-			break;
 		case Opt_stripe:
 			if (match_int(&args[0], &option))
 				return 0;
@@ -1373,10 +1375,17 @@ set_qf_format:
 		case Opt_delalloc:
 			set_opt(sbi->s_mount_opt, DELALLOC);
 			break;
+		case Opt_inode_readahead_blks:
+			if (match_int(&args[0], &option))
+				return 0;
+			if (option < 0 || option > (1 << 30))
+				return 0;
+			sbi->s_inode_readahead_blks = option;
+			break;
 		default:
-			printk (KERN_ERR
-				"EXT4-fs: Unrecognized mount option \"%s\" "
-				"or missing value\n", p);
+			printk(KERN_ERR
+			       "EXT4-fs: Unrecognized mount option \"%s\" "
+			       "or missing value\n", p);
 			return 0;
 		}
 	}
@@ -1423,31 +1432,31 @@ static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
 	int res = 0;
 
 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
-		printk (KERN_ERR "EXT4-fs warning: revision level too high, "
-			"forcing read-only mode\n");
+		printk(KERN_ERR "EXT4-fs warning: revision level too high, "
+		       "forcing read-only mode\n");
 		res = MS_RDONLY;
 	}
 	if (read_only)
 		return res;
 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
-		printk (KERN_WARNING "EXT4-fs warning: mounting unchecked fs, "
-			"running e2fsck is recommended\n");
+		printk(KERN_WARNING "EXT4-fs warning: mounting unchecked fs, "
+		       "running e2fsck is recommended\n");
 	else if ((sbi->s_mount_state & EXT4_ERROR_FS))
-		printk (KERN_WARNING
-			"EXT4-fs warning: mounting fs with errors, "
-			"running e2fsck is recommended\n");
+		printk(KERN_WARNING
+		       "EXT4-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
-			"EXT4-fs warning: maximal mount count reached, "
-			"running e2fsck is recommended\n");
+		printk(KERN_WARNING
+		       "EXT4-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) <= get_seconds()))
-		printk (KERN_WARNING
-			"EXT4-fs warning: checktime reached, "
-			"running e2fsck is recommended\n");
+		printk(KERN_WARNING
+		       "EXT4-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
@@ -1473,15 +1482,9 @@ static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
 			EXT4_INODES_PER_GROUP(sb),
 			sbi->s_mount_opt);
 
-	printk(KERN_INFO "EXT4 FS on %s, ", sb->s_id);
-	if (EXT4_SB(sb)->s_journal->j_inode == NULL) {
-		char b[BDEVNAME_SIZE];
-
-		printk("external journal on %s\n",
-			bdevname(EXT4_SB(sb)->s_journal->j_dev, b));
-	} else {
-		printk("internal journal\n");
-	}
+	printk(KERN_INFO "EXT4 FS on %s, %s journal on %s\n",
+	       sb->s_id, EXT4_SB(sb)->s_journal->j_inode ? "internal" :
+	       "external", EXT4_SB(sb)->s_journal->j_devname);
 	return res;
 }
 
@@ -1504,16 +1507,18 @@ static int ext4_fill_flex_info(struct super_block *sb)
 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
 	groups_per_flex = 1 << sbi->s_log_groups_per_flex;
 
-	flex_group_count = (sbi->s_groups_count + groups_per_flex - 1) /
-		groups_per_flex;
-	sbi->s_flex_groups = kmalloc(flex_group_count *
+	/* We allocate both existing and potentially added groups */
+	flex_group_count = ((sbi->s_groups_count + groups_per_flex - 1) +
+			    ((sbi->s_es->s_reserved_gdt_blocks +1 ) <<
+			      EXT4_DESC_PER_BLOCK_BITS(sb))) /
+			   groups_per_flex;
+	sbi->s_flex_groups = kzalloc(flex_group_count *
 				     sizeof(struct flex_groups), GFP_KERNEL);
 	if (sbi->s_flex_groups == NULL) {
-		printk(KERN_ERR "EXT4-fs: not enough memory\n");
+		printk(KERN_ERR "EXT4-fs: not enough memory for "
+				"%lu flex groups\n", flex_group_count);
 		goto failed;
 	}
-	memset(sbi->s_flex_groups, 0, flex_group_count *
-	       sizeof(struct flex_groups));
 
 	gdp = ext4_get_group_desc(sb, 1, &bh);
 	block_bitmap = ext4_block_bitmap(sb, gdp) - 1;
@@ -1585,7 +1590,7 @@ static int ext4_check_descriptors(struct super_block *sb)
 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
 		flexbg_flag = 1;
 
-	ext4_debug ("Checking group descriptors");
+	ext4_debug("Checking group descriptors");
 
 	for (i = 0; i < sbi->s_groups_count; i++) {
 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
@@ -1597,16 +1602,14 @@ static int ext4_check_descriptors(struct super_block *sb)
 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
 
 		block_bitmap = ext4_block_bitmap(sb, gdp);
-		if (block_bitmap < first_block || block_bitmap > last_block)
-		{
+		if (block_bitmap < first_block || block_bitmap > last_block) {
 			printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
 			       "Block bitmap for group %lu not in group "
 			       "(block %llu)!", i, block_bitmap);
 			return 0;
 		}
 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
-		if (inode_bitmap < first_block || inode_bitmap > last_block)
-		{
+		if (inode_bitmap < first_block || inode_bitmap > last_block) {
 			printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
 			       "Inode bitmap for group %lu not in group "
 			       "(block %llu)!", i, inode_bitmap);
@@ -1614,26 +1617,30 @@ static int ext4_check_descriptors(struct super_block *sb)
 		}
 		inode_table = ext4_inode_table(sb, gdp);
 		if (inode_table < first_block ||
-		    inode_table + sbi->s_itb_per_group - 1 > last_block)
-		{
+		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
 			printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
 			       "Inode table for group %lu not in group "
 			       "(block %llu)!", i, inode_table);
 			return 0;
 		}
+		spin_lock(sb_bgl_lock(sbi, i));
 		if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
 			printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
 			       "Checksum for group %lu failed (%u!=%u)\n",
 			       i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
 			       gdp)), le16_to_cpu(gdp->bg_checksum));
-			return 0;
+			if (!(sb->s_flags & MS_RDONLY)) {
+				spin_unlock(sb_bgl_lock(sbi, i));
+				return 0;
+			}
 		}
+		spin_unlock(sb_bgl_lock(sbi, i));
 		if (!flexbg_flag)
 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
 	}
 
 	ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
-	sbi->s_es->s_free_inodes_count=cpu_to_le32(ext4_count_free_inodes(sb));
+	sbi->s_es->s_free_inodes_count = cpu_to_le32(ext4_count_free_inodes(sb));
 	return 1;
 }
 
@@ -1654,8 +1661,8 @@ static int ext4_check_descriptors(struct super_block *sb)
  * 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 ext4_orphan_cleanup (struct super_block * sb,
-				 struct ext4_super_block * es)
+static void ext4_orphan_cleanup(struct super_block *sb,
+				struct ext4_super_block *es)
 {
 	unsigned int s_flags = sb->s_flags;
 	int nr_orphans = 0, nr_truncates = 0;
@@ -1715,9 +1722,9 @@ static void ext4_orphan_cleanup (struct super_block * sb,
 		DQUOT_INIT(inode);
 		if (inode->i_nlink) {
 			printk(KERN_DEBUG
-				"%s: truncating inode %lu to %Ld bytes\n",
+				"%s: truncating inode %lu to %lld bytes\n",
 				__func__, inode->i_ino, inode->i_size);
-			jbd_debug(2, "truncating inode %lu to %Ld bytes\n",
+			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
 				  inode->i_ino, inode->i_size);
 			ext4_truncate(inode);
 			nr_truncates++;
@@ -1732,7 +1739,7 @@ static void ext4_orphan_cleanup (struct super_block * sb,
 		iput(inode);  /* The delete magic happens here! */
 	}
 
-#define PLURAL(x) (x), ((x)==1) ? "" : "s"
+#define PLURAL(x) (x), ((x) == 1) ? "" : "s"
 
 	if (nr_orphans)
 		printk(KERN_INFO "EXT4-fs: %s: %d orphan inode%s deleted\n",
@@ -1899,12 +1906,12 @@ static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
 	return 0;
 }
 
-static int ext4_fill_super (struct super_block *sb, void *data, int silent)
+static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 				__releases(kernel_lock)
 				__acquires(kernel_lock)
 
 {
-	struct buffer_head * bh;
+	struct buffer_head *bh;
 	struct ext4_super_block *es = NULL;
 	struct ext4_sb_info *sbi;
 	ext4_fsblk_t block;
@@ -1915,6 +1922,7 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 	unsigned long journal_devnum = 0;
 	unsigned long def_mount_opts;
 	struct inode *root;
+	char *cp;
 	int ret = -EINVAL;
 	int blocksize;
 	int db_count;
@@ -1931,10 +1939,15 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 	sbi->s_mount_opt = 0;
 	sbi->s_resuid = EXT4_DEF_RESUID;
 	sbi->s_resgid = EXT4_DEF_RESGID;
+	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
 	sbi->s_sb_block = sb_block;
 
 	unlock_kernel();
 
+	/* Cleanup superblock name */
+	for (cp = sb->s_id; (cp = strchr(cp, '/'));)
+		*cp = '!';
+
 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
 	if (!blocksize) {
 		printk(KERN_ERR "EXT4-fs: unable to set blocksize\n");
@@ -1953,7 +1966,7 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 	}
 
 	if (!(bh = sb_bread(sb, logical_sb_block))) {
-		printk (KERN_ERR "EXT4-fs: unable to read superblock\n");
+		printk(KERN_ERR "EXT4-fs: unable to read superblock\n");
 		goto out_fail;
 	}
 	/*
@@ -2013,11 +2026,6 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 		ext4_warning(sb, __func__,
 			"extents feature not enabled on this filesystem, "
 			"use tune2fs.\n");
-	/*
-	 * turn on mballoc code by default in ext4 filesystem
-	 * Use -o nomballoc to turn it off
-	 */
-	set_opt(sbi->s_mount_opt, MBALLOC);
 
 	/*
 	 * enable delayed allocation by default
@@ -2026,8 +2034,8 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 	set_opt(sbi->s_mount_opt, DELALLOC);
 
 
-	if (!parse_options ((char *) data, sb, &journal_inum, &journal_devnum,
-			    NULL, 0))
+	if (!parse_options((char *) data, sb, &journal_inum, &journal_devnum,
+			   NULL, 0))
 		goto failed_mount;
 
 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
@@ -2102,7 +2110,7 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 			goto failed_mount;
 		}
 
-		brelse (bh);
+		brelse(bh);
 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
 		offset = do_div(logical_sb_block, blocksize);
 		bh = sb_bread(sb, logical_sb_block);
@@ -2114,8 +2122,8 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 		es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
 		sbi->s_es = es;
 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
-			printk (KERN_ERR
-				"EXT4-fs: Magic mismatch, very weird !\n");
+			printk(KERN_ERR
+			       "EXT4-fs: Magic mismatch, very weird !\n");
 			goto failed_mount;
 		}
 	}
@@ -2132,9 +2140,9 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
 		    (!is_power_of_2(sbi->s_inode_size)) ||
 		    (sbi->s_inode_size > blocksize)) {
-			printk (KERN_ERR
-				"EXT4-fs: unsupported inode size: %d\n",
-				sbi->s_inode_size);
+			printk(KERN_ERR
+			       "EXT4-fs: unsupported inode size: %d\n",
+			       sbi->s_inode_size);
 			goto failed_mount;
 		}
 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
@@ -2166,20 +2174,20 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 	sbi->s_mount_state = le16_to_cpu(es->s_state);
 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
-	for (i=0; i < 4; i++)
+	for (i = 0; i < 4; i++)
 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
 	sbi->s_def_hash_version = es->s_def_hash_version;
 
 	if (sbi->s_blocks_per_group > blocksize * 8) {
-		printk (KERN_ERR
-			"EXT4-fs: #blocks per group too big: %lu\n",
-			sbi->s_blocks_per_group);
+		printk(KERN_ERR
+		       "EXT4-fs: #blocks per group too big: %lu\n",
+		       sbi->s_blocks_per_group);
 		goto failed_mount;
 	}
 	if (sbi->s_inodes_per_group > blocksize * 8) {
-		printk (KERN_ERR
-			"EXT4-fs: #inodes per group too big: %lu\n",
-			sbi->s_inodes_per_group);
+		printk(KERN_ERR
+		       "EXT4-fs: #inodes per group too big: %lu\n",
+		       sbi->s_inodes_per_group);
 		goto failed_mount;
 	}
 
@@ -2213,26 +2221,34 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 	sbi->s_groups_count = blocks_count;
 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
 		   EXT4_DESC_PER_BLOCK(sb);
-	sbi->s_group_desc = kmalloc(db_count * sizeof (struct buffer_head *),
+	sbi->s_group_desc = kmalloc(db_count * sizeof(struct buffer_head *),
 				    GFP_KERNEL);
 	if (sbi->s_group_desc == NULL) {
-		printk (KERN_ERR "EXT4-fs: not enough memory\n");
+		printk(KERN_ERR "EXT4-fs: not enough memory\n");
 		goto failed_mount;
 	}
 
+	if (ext4_proc_root)
+		sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
+
+	if (sbi->s_proc)
+		proc_create_data("inode_readahead_blks", 0644, sbi->s_proc,
+				 &ext4_ui_proc_fops,
+				 &sbi->s_inode_readahead_blks);
+
 	bgl_lock_init(&sbi->s_blockgroup_lock);
 
 	for (i = 0; i < db_count; i++) {
 		block = descriptor_loc(sb, logical_sb_block, i);
 		sbi->s_group_desc[i] = sb_bread(sb, block);
 		if (!sbi->s_group_desc[i]) {
-			printk (KERN_ERR "EXT4-fs: "
-				"can't read group descriptor %d\n", i);
+			printk(KERN_ERR "EXT4-fs: "
+			       "can't read group descriptor %d\n", i);
 			db_count = i;
 			goto failed_mount2;
 		}
 	}
-	if (!ext4_check_descriptors (sb)) {
+	if (!ext4_check_descriptors(sb)) {
 		printk(KERN_ERR "EXT4-fs: group descriptors corrupted!\n");
 		goto failed_mount2;
 	}
@@ -2258,24 +2274,14 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 		err = percpu_counter_init(&sbi->s_dirs_counter,
 				ext4_count_dirs(sb));
 	}
+	if (!err) {
+		err = percpu_counter_init(&sbi->s_dirtyblocks_counter, 0);
+	}
 	if (err) {
 		printk(KERN_ERR "EXT4-fs: insufficient memory\n");
 		goto failed_mount3;
 	}
 
-	/* 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 = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
-	sbi->s_rsv_window_head.rsv_end = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
-	sbi->s_rsv_window_head.rsv_alloc_hit = 0;
-	sbi->s_rsv_window_head.rsv_goal_size = 0;
-	ext4_rsv_window_add(sb, &sbi->s_rsv_window_head);
-
 	sbi->s_stripe = ext4_get_stripe_size(sbi);
 
 	/*
@@ -2308,11 +2314,11 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 		    EXT4_SB(sb)->s_journal->j_failed_commit) {
 			printk(KERN_CRIT "EXT4-fs error (device %s): "
 			       "ext4_fill_super: Journal transaction "
-			       "%u is corrupt\n", sb->s_id, 
+			       "%u is corrupt\n", sb->s_id,
 			       EXT4_SB(sb)->s_journal->j_failed_commit);
-			if (test_opt (sb, ERRORS_RO)) {
-				printk (KERN_CRIT
-					"Mounting filesystem read-only\n");
+			if (test_opt(sb, ERRORS_RO)) {
+				printk(KERN_CRIT
+				       "Mounting filesystem read-only\n");
 				sb->s_flags |= MS_RDONLY;
 				EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 				es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
@@ -2332,9 +2338,9 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 			goto failed_mount3;
 	} else {
 		if (!silent)
-			printk (KERN_ERR
-				"ext4: No journal on filesystem on %s\n",
-				sb->s_id);
+			printk(KERN_ERR
+			       "ext4: No journal on filesystem on %s\n",
+			       sb->s_id);
 		goto failed_mount3;
 	}
 
@@ -2418,7 +2424,7 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 		goto failed_mount4;
 	}
 
-	ext4_setup_super (sb, es, sb->s_flags & MS_RDONLY);
+	ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY);
 
 	/* determine the minimum size of new large inodes, if present */
 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
@@ -2457,12 +2463,12 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 	ext4_orphan_cleanup(sb, es);
 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
 	if (needs_recovery)
-		printk (KERN_INFO "EXT4-fs: recovery complete.\n");
+		printk(KERN_INFO "EXT4-fs: recovery complete.\n");
 	ext4_mark_recovery_complete(sb, es);
-	printk (KERN_INFO "EXT4-fs: mounted filesystem with %s data mode.\n",
-		test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ? "journal":
-		test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA ? "ordered":
-		"writeback");
+	printk(KERN_INFO "EXT4-fs: mounted filesystem with %s data mode.\n",
+	       test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ? "journal":
+	       test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA ? "ordered":
+	       "writeback");
 
 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
 		printk(KERN_WARNING "EXT4-fs: Ignoring delalloc option - "
@@ -2472,7 +2478,12 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 		printk(KERN_INFO "EXT4-fs: delayed allocation enabled\n");
 
 	ext4_ext_init(sb);
-	ext4_mb_init(sb, needs_recovery);
+	err = ext4_mb_init(sb, needs_recovery);
+	if (err) {
+		printk(KERN_ERR "EXT4-fs: failed to initalize mballoc (%d)\n",
+		       err);
+		goto failed_mount4;
+	}
 
 	lock_kernel();
 	return 0;
@@ -2490,11 +2501,16 @@ failed_mount3:
 	percpu_counter_destroy(&sbi->s_freeblocks_counter);
 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
 	percpu_counter_destroy(&sbi->s_dirs_counter);
+	percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
 failed_mount2:
 	for (i = 0; i < db_count; i++)
 		brelse(sbi->s_group_desc[i]);
 	kfree(sbi->s_group_desc);
 failed_mount:
+	if (sbi->s_proc) {
+		remove_proc_entry("inode_readahead_blks", sbi->s_proc);
+		remove_proc_entry(sb->s_id, ext4_proc_root);
+	}
 #ifdef CONFIG_QUOTA
 	for (i = 0; i < MAXQUOTAS; i++)
 		kfree(sbi->s_qf_names[i]);
@@ -2553,7 +2569,7 @@ static journal_t *ext4_get_journal(struct super_block *sb,
 		return NULL;
 	}
 
-	jbd_debug(2, "Journal inode found at %p: %Ld bytes\n",
+	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
 		  journal_inode, journal_inode->i_size);
 	if (!S_ISREG(journal_inode->i_mode)) {
 		printk(KERN_ERR "EXT4-fs: invalid journal inode.\n");
@@ -2575,14 +2591,14 @@ static journal_t *ext4_get_journal(struct super_block *sb,
 static journal_t *ext4_get_dev_journal(struct super_block *sb,
 				       dev_t j_dev)
 {
-	struct buffer_head * bh;
+	struct buffer_head *bh;
 	journal_t *journal;
 	ext4_fsblk_t start;
 	ext4_fsblk_t len;
 	int hblock, blocksize;
 	ext4_fsblk_t sb_block;
 	unsigned long offset;
-	struct ext4_super_block * es;
+	struct ext4_super_block *es;
 	struct block_device *bdev;
 
 	bdev = ext4_blkdev_get(j_dev);
@@ -2697,8 +2713,8 @@ static int ext4_load_journal(struct super_block *sb,
 					"unavailable, cannot proceed.\n");
 				return -EROFS;
 			}
-			printk (KERN_INFO "EXT4-fs: write access will "
-					"be enabled during recovery.\n");
+			printk(KERN_INFO "EXT4-fs: write access will "
+			       "be enabled during recovery.\n");
 		}
 	}
 
@@ -2716,6 +2732,11 @@ static int ext4_load_journal(struct super_block *sb,
 			return -EINVAL;
 	}
 
+	if (journal->j_flags & JBD2_BARRIER)
+		printk(KERN_INFO "EXT4-fs: barriers enabled\n");
+	else
+		printk(KERN_INFO "EXT4-fs: barriers disabled\n");
+
 	if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
 		err = jbd2_journal_update_format(journal);
 		if (err)  {
@@ -2751,8 +2772,8 @@ static int ext4_load_journal(struct super_block *sb,
 	return 0;
 }
 
-static int ext4_create_journal(struct super_block * sb,
-			       struct ext4_super_block * es,
+static int ext4_create_journal(struct super_block *sb,
+			       struct ext4_super_block *es,
 			       unsigned int journal_inum)
 {
 	journal_t *journal;
@@ -2793,21 +2814,41 @@ static int ext4_create_journal(struct super_block * sb,
 	return 0;
 }
 
-static void ext4_commit_super (struct super_block * sb,
-			       struct ext4_super_block * es,
-			       int sync)
+static void ext4_commit_super(struct super_block *sb,
+			      struct ext4_super_block *es, int sync)
 {
 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
 
 	if (!sbh)
 		return;
+	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.
+		 */
+		printk(KERN_ERR "ext4: previous I/O error to "
+		       "superblock detected for %s.\n", sb->s_id);
+		clear_buffer_write_io_error(sbh);
+		set_buffer_uptodate(sbh);
+	}
 	es->s_wtime = cpu_to_le32(get_seconds());
 	ext4_free_blocks_count_set(es, ext4_count_free_blocks(sb));
 	es->s_free_inodes_count = cpu_to_le32(ext4_count_free_inodes(sb));
 	BUFFER_TRACE(sbh, "marking dirty");
 	mark_buffer_dirty(sbh);
-	if (sync)
+	if (sync) {
 		sync_dirty_buffer(sbh);
+		if (buffer_write_io_error(sbh)) {
+			printk(KERN_ERR "ext4: I/O error while writing "
+			       "superblock for %s.\n", sb->s_id);
+			clear_buffer_write_io_error(sbh);
+			set_buffer_uptodate(sbh);
+		}
+	}
 }
 
 
@@ -2816,8 +2857,8 @@ static void ext4_commit_super (struct super_block * sb,
  * remounting) the filesystem readonly, then we will end up with a
  * consistent fs on disk.  Record that fact.
  */
-static void ext4_mark_recovery_complete(struct super_block * sb,
-					struct ext4_super_block * es)
+static void ext4_mark_recovery_complete(struct super_block *sb,
+					struct ext4_super_block *es)
 {
 	journal_t *journal = EXT4_SB(sb)->s_journal;
 
@@ -2839,8 +2880,8 @@ static void ext4_mark_recovery_complete(struct super_block * sb,
  * has recorded an error from a previous lifetime, move that error to the
  * main filesystem now.
  */
-static void ext4_clear_journal_err(struct super_block * sb,
-				   struct ext4_super_block * es)
+static void ext4_clear_journal_err(struct super_block *sb,
+				   struct ext4_super_block *es)
 {
 	journal_t *journal;
 	int j_errno;
@@ -2865,7 +2906,7 @@ static void ext4_clear_journal_err(struct super_block * sb,
 
 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
-		ext4_commit_super (sb, es, 1);
+		ext4_commit_super(sb, es, 1);
 
 		jbd2_journal_clear_err(journal);
 	}
@@ -2898,7 +2939,7 @@ int ext4_force_commit(struct super_block *sb)
  * This implicitly triggers the writebehind on sync().
  */
 
-static void ext4_write_super (struct super_block * sb)
+static void ext4_write_super(struct super_block *sb)
 {
 	if (mutex_trylock(&sb->s_lock) != 0)
 		BUG();
@@ -2909,6 +2950,7 @@ static int ext4_sync_fs(struct super_block *sb, int wait)
 {
 	tid_t target;
 
+	trace_mark(ext4_sync_fs, "dev %s wait %d", sb->s_id, wait);
 	sb->s_dirt = 0;
 	if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal, &target)) {
 		if (wait)
@@ -2954,13 +2996,14 @@ static void ext4_unlockfs(struct super_block *sb)
 	}
 }
 
-static int ext4_remount (struct super_block * sb, int * flags, char * data)
+static int ext4_remount(struct super_block *sb, int *flags, char *data)
 {
-	struct ext4_super_block * es;
+	struct ext4_super_block *es;
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
 	ext4_fsblk_t n_blocks_count = 0;
 	unsigned long old_sb_flags;
 	struct ext4_mount_options old_opts;
+	ext4_group_t g;
 	int err;
 #ifdef CONFIG_QUOTA
 	int i;
@@ -3038,6 +3081,26 @@ static int ext4_remount (struct super_block * sb, int * flags, char * data)
 				goto restore_opts;
 			}
 
+			/*
+			 * Make sure the group descriptor checksums
+			 * are sane.  If they aren't, refuse to
+			 * remount r/w.
+			 */
+			for (g = 0; g < sbi->s_groups_count; g++) {
+				struct ext4_group_desc *gdp =
+					ext4_get_group_desc(sb, g, NULL);
+
+				if (!ext4_group_desc_csum_verify(sbi, g, gdp)) {
+					printk(KERN_ERR
+	       "EXT4-fs: ext4_remount: "
+		"Checksum for group %lu failed (%u!=%u)\n",
+		g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
+					       le16_to_cpu(gdp->bg_checksum));
+					err = -EINVAL;
+					goto restore_opts;
+				}
+			}
+
 			/*
 			 * If we have an unprocessed orphan list hanging
 			 * around from a previously readonly bdev mount,
@@ -3063,7 +3126,7 @@ static int ext4_remount (struct super_block * sb, int * flags, char * data)
 			sbi->s_mount_state = le16_to_cpu(es->s_state);
 			if ((err = ext4_group_extend(sb, es, n_blocks_count)))
 				goto restore_opts;
-			if (!ext4_setup_super (sb, es, 0))
+			if (!ext4_setup_super(sb, es, 0))
 				sb->s_flags &= ~MS_RDONLY;
 		}
 	}
@@ -3093,7 +3156,7 @@ restore_opts:
 	return err;
 }
 
-static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf)
+static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
 {
 	struct super_block *sb = dentry->d_sb;
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
@@ -3143,7 +3206,8 @@ static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf)
 	buf->f_type = EXT4_SUPER_MAGIC;
 	buf->f_bsize = sb->s_blocksize;
 	buf->f_blocks = ext4_blocks_count(es) - sbi->s_overhead_last;
-	buf->f_bfree = percpu_counter_sum_positive(&sbi->s_freeblocks_counter);
+	buf->f_bfree = percpu_counter_sum_positive(&sbi->s_freeblocks_counter) -
+		       percpu_counter_sum_positive(&sbi->s_dirtyblocks_counter);
 	ext4_free_blocks_count_set(es, buf->f_bfree);
 	buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
 	if (buf->f_bfree < ext4_r_blocks_count(es))
@@ -3331,12 +3395,12 @@ static int ext4_quota_on(struct super_block *sb, int type, int format_id,
 	}
 	/* Journaling quota? */
 	if (EXT4_SB(sb)->s_qf_names[type]) {
-		/* Quotafile not of fs root? */
+		/* Quotafile not in fs root? */
 		if (nd.path.dentry->d_parent->d_inode != sb->s_root->d_inode)
 			printk(KERN_WARNING
 				"EXT4-fs: Quota file not on filesystem root. "
 				"Journaled quota will not work.\n");
- 	}
+	}
 
 	/*
 	 * When we journal data on quota file, we have to flush journal to see
@@ -3413,7 +3477,7 @@ static ssize_t ext4_quota_write(struct super_block *sb, int type,
 	handle_t *handle = journal_current_handle();
 
 	if (!handle) {
-		printk(KERN_WARNING "EXT4-fs: Quota write (off=%Lu, len=%Lu)"
+		printk(KERN_WARNING "EXT4-fs: Quota write (off=%llu, len=%llu)"
 			" cancelled because transaction is not started.\n",
 			(unsigned long long)off, (unsigned long long)len);
 		return -EIO;
@@ -3474,6 +3538,48 @@ static int ext4_get_sb(struct file_system_type *fs_type,
 	return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super, mnt);
 }
 
+#ifdef CONFIG_PROC_FS
+static int ext4_ui_proc_show(struct seq_file *m, void *v)
+{
+	unsigned int *p = m->private;
+
+	seq_printf(m, "%u\n", *p);
+	return 0;
+}
+
+static int ext4_ui_proc_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, ext4_ui_proc_show, PDE(inode)->data);
+}
+
+static ssize_t ext4_ui_proc_write(struct file *file, const char __user *buf,
+			       size_t cnt, loff_t *ppos)
+{
+	unsigned int *p = PDE(file->f_path.dentry->d_inode)->data;
+	char str[32];
+	unsigned long value;
+
+	if (cnt >= sizeof(str))
+		return -EINVAL;
+	if (copy_from_user(str, buf, cnt))
+		return -EFAULT;
+	value = simple_strtol(str, NULL, 0);
+	if (value < 0)
+		return -ERANGE;
+	*p = value;
+	return cnt;
+}
+
+const struct file_operations ext4_ui_proc_fops = {
+	.owner		= THIS_MODULE,
+	.open		= ext4_ui_proc_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+	.write		= ext4_ui_proc_write,
+};
+#endif
+
 static struct file_system_type ext4dev_fs_type = {
 	.owner		= THIS_MODULE,
 	.name		= "ext4dev",
@@ -3486,6 +3592,7 @@ static int __init init_ext4_fs(void)
 {
 	int err;
 
+	ext4_proc_root = proc_mkdir("fs/ext4", NULL);
 	err = init_ext4_mballoc();
 	if (err)
 		return err;
@@ -3515,6 +3622,7 @@ static void __exit exit_ext4_fs(void)
 	destroy_inodecache();
 	exit_ext4_xattr();
 	exit_ext4_mballoc();
+	remove_proc_entry("fs/ext4", NULL);
 }
 
 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");