1 files changed, 394 insertions, 323 deletions

diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index 4a4ab683250d..121e634c792a 100644
--- a/fs/ext2/super.c
+++ b/fs/ext2/super.c
@@ -23,7 +23,8 @@
 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/blkdev.h>
-#include <linux/parser.h>
+#include <linux/fs_context.h>
+#include <linux/fs_parser.h>
 #include <linux/random.h>
 #include <linux/buffer_head.h>
 #include <linux/exportfs.h>
@@ -40,7 +41,6 @@
 #include "acl.h"
 
 static void ext2_write_super(struct super_block *sb);
-static int ext2_remount (struct super_block * sb, int * flags, char * data);
 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
 static int ext2_sync_fs(struct super_block *sb, int wait);
 static int ext2_freeze(struct super_block *sb);
@@ -81,6 +81,33 @@ void ext2_error(struct super_block *sb, const char *function,
 	}
 }
 
+static void ext2_msg_fc(struct fs_context *fc, const char *prefix,
+			const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+	const char *s_id;
+
+	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
+		s_id = fc->root->d_sb->s_id;
+	} else {
+		/* get last path component of source */
+		s_id = strrchr(fc->source, '/');
+		if (s_id)
+			s_id++;
+		else
+			s_id = fc->source;
+	}
+	va_start(args, fmt);
+
+	vaf.fmt = fmt;
+	vaf.va = &args;
+
+	printk("%sEXT2-fs (%s): %pV\n", prefix, s_id, &vaf);
+
+	va_end(args);
+}
+
 void ext2_msg(struct super_block *sb, const char *prefix,
 		const char *fmt, ...)
 {
@@ -163,7 +190,7 @@ static void ext2_put_super (struct super_block * sb)
 	db_count = sbi->s_gdb_count;
 	for (i = 0; i < db_count; i++)
 		brelse(sbi->s_group_desc[i]);
-	kfree(sbi->s_group_desc);
+	kvfree(sbi->s_group_desc);
 	kfree(sbi->s_debts);
 	percpu_counter_destroy(&sbi->s_freeblocks_counter);
 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
@@ -171,7 +198,7 @@ static void ext2_put_super (struct super_block * sb)
 	brelse (sbi->s_sbh);
 	sb->s_fs_info = NULL;
 	kfree(sbi->s_blockgroup_lock);
-	fs_put_dax(sbi->s_daxdev);
+	fs_put_dax(sbi->s_daxdev, NULL);
 	kfree(sbi);
 }
 
@@ -180,7 +207,7 @@ static struct kmem_cache * ext2_inode_cachep;
 static struct inode *ext2_alloc_inode(struct super_block *sb)
 {
 	struct ext2_inode_info *ei;
-	ei = kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
+	ei = alloc_inode_sb(sb, ext2_inode_cachep, GFP_KERNEL);
 	if (!ei)
 		return NULL;
 	ei->i_block_alloc_info = NULL;
@@ -206,9 +233,6 @@ static void init_once(void *foo)
 	init_rwsem(&ei->xattr_sem);
 #endif
 	mutex_init(&ei->truncate_mutex);
-#ifdef CONFIG_FS_DAX
-	init_rwsem(&ei->dax_sem);
-#endif
 	inode_init_once(&ei->vfs_inode);
 }
 
@@ -216,8 +240,7 @@ static int __init init_inodecache(void)
 {
 	ext2_inode_cachep = kmem_cache_create_usercopy("ext2_inode_cache",
 				sizeof(struct ext2_inode_info), 0,
-				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
-					SLAB_ACCOUNT),
+				SLAB_RECLAIM_ACCOUNT | SLAB_ACCOUNT,
 				offsetof(struct ext2_inode_info, i_data),
 				sizeof_field(struct ext2_inode_info, i_data),
 				init_once);
@@ -299,9 +322,6 @@ static int ext2_show_options(struct seq_file *seq, struct dentry *root)
 		seq_puts(seq, ",noacl");
 #endif
 
-	if (test_opt(sb, NOBH))
-		seq_puts(seq, ",nobh");
-
 	if (test_opt(sb, USRQUOTA))
 		seq_puts(seq, ",usrquota");
 
@@ -326,7 +346,7 @@ static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, siz
 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
 static int ext2_quota_on(struct super_block *sb, int type, int format_id,
 			 const struct path *path);
-static struct dquot **ext2_get_dquots(struct inode *inode)
+static struct dquot __rcu **ext2_get_dquots(struct inode *inode)
 {
 	return EXT2_I(inode)->i_dquot;
 }
@@ -353,7 +373,6 @@ static const struct super_operations ext2_sops = {
 	.freeze_fs	= ext2_freeze,
 	.unfreeze_fs	= ext2_unfreeze,
 	.statfs		= ext2_statfs,
-	.remount_fs	= ext2_remount,
 	.show_options	= ext2_show_options,
 #ifdef CONFIG_QUOTA
 	.quota_read	= ext2_quota_read,
@@ -403,242 +422,224 @@ static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
 }
 
 static const struct export_operations ext2_export_ops = {
+	.encode_fh = generic_encode_ino32_fh,
 	.fh_to_dentry = ext2_fh_to_dentry,
 	.fh_to_parent = ext2_fh_to_parent,
 	.get_parent = ext2_get_parent,
 };
 
-static unsigned long get_sb_block(void **data)
-{
-	unsigned long 	sb_block;
-	char 		*options = (char *) *data;
-
-	if (!options || strncmp(options, "sb=", 3) != 0)
-		return 1;	/* Default location */
-	options += 3;
-	sb_block = simple_strtoul(options, &options, 0);
-	if (*options && *options != ',') {
-		printk("EXT2-fs: Invalid sb specification: %s\n",
-		       (char *) *data);
-		return 1;
-	}
-	if (*options == ',')
-		options++;
-	*data = (void *) options;
-	return sb_block;
-}
-
 enum {
-	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
-	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
-	Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
-	Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
-	Opt_acl, Opt_noacl, Opt_xip, Opt_dax, Opt_ignore, Opt_err, Opt_quota,
-	Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
+	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid, Opt_resgid, Opt_resuid,
+	Opt_sb, Opt_errors, Opt_nouid32, Opt_debug, Opt_oldalloc, Opt_orlov,
+	Opt_nobh, Opt_user_xattr, Opt_acl, Opt_xip, Opt_dax, Opt_ignore,
+	Opt_quota, Opt_usrquota, Opt_grpquota, Opt_reservation,
 };
 
-static const match_table_t tokens = {
-	{Opt_bsd_df, "bsddf"},
-	{Opt_minix_df, "minixdf"},
-	{Opt_grpid, "grpid"},
-	{Opt_grpid, "bsdgroups"},
-	{Opt_nogrpid, "nogrpid"},
-	{Opt_nogrpid, "sysvgroups"},
-	{Opt_resgid, "resgid=%u"},
-	{Opt_resuid, "resuid=%u"},
-	{Opt_sb, "sb=%u"},
-	{Opt_err_cont, "errors=continue"},
-	{Opt_err_panic, "errors=panic"},
-	{Opt_err_ro, "errors=remount-ro"},
-	{Opt_nouid32, "nouid32"},
-	{Opt_nocheck, "check=none"},
-	{Opt_nocheck, "nocheck"},
-	{Opt_debug, "debug"},
-	{Opt_oldalloc, "oldalloc"},
-	{Opt_orlov, "orlov"},
-	{Opt_nobh, "nobh"},
-	{Opt_user_xattr, "user_xattr"},
-	{Opt_nouser_xattr, "nouser_xattr"},
-	{Opt_acl, "acl"},
-	{Opt_noacl, "noacl"},
-	{Opt_xip, "xip"},
-	{Opt_dax, "dax"},
-	{Opt_grpquota, "grpquota"},
-	{Opt_ignore, "noquota"},
-	{Opt_quota, "quota"},
-	{Opt_usrquota, "usrquota"},
-	{Opt_reservation, "reservation"},
-	{Opt_noreservation, "noreservation"},
-	{Opt_err, NULL}
+static const struct constant_table ext2_param_errors[] = {
+	{"continue",	EXT2_MOUNT_ERRORS_CONT},
+	{"panic",	EXT2_MOUNT_ERRORS_PANIC},
+	{"remount-ro",	EXT2_MOUNT_ERRORS_RO},
+	{}
 };
 
-static int parse_options(char *options, struct super_block *sb,
-			 struct ext2_mount_options *opts)
+static const struct fs_parameter_spec ext2_param_spec[] = {
+	fsparam_flag	("bsddf", Opt_bsd_df),
+	fsparam_flag	("minixdf", Opt_minix_df),
+	fsparam_flag	("grpid", Opt_grpid),
+	fsparam_flag	("bsdgroups", Opt_grpid),
+	fsparam_flag	("nogrpid", Opt_nogrpid),
+	fsparam_flag	("sysvgroups", Opt_nogrpid),
+	fsparam_gid	("resgid", Opt_resgid),
+	fsparam_uid	("resuid", Opt_resuid),
+	fsparam_u32	("sb", Opt_sb),
+	fsparam_enum	("errors", Opt_errors, ext2_param_errors),
+	fsparam_flag	("nouid32", Opt_nouid32),
+	fsparam_flag	("debug", Opt_debug),
+	fsparam_flag	("oldalloc", Opt_oldalloc),
+	fsparam_flag	("orlov", Opt_orlov),
+	fsparam_flag	("nobh", Opt_nobh),
+	fsparam_flag_no	("user_xattr", Opt_user_xattr),
+	fsparam_flag_no	("acl", Opt_acl),
+	fsparam_flag	("xip", Opt_xip),
+	fsparam_flag	("dax", Opt_dax),
+	fsparam_flag	("grpquota", Opt_grpquota),
+	fsparam_flag	("noquota", Opt_ignore),
+	fsparam_flag	("quota", Opt_quota),
+	fsparam_flag	("usrquota", Opt_usrquota),
+	fsparam_flag_no	("reservation", Opt_reservation),
+	{}
+};
+
+#define EXT2_SPEC_s_resuid                      (1 << 0)
+#define EXT2_SPEC_s_resgid                      (1 << 1)
+
+struct ext2_fs_context {
+	unsigned long	vals_s_flags;	/* Bits to set in s_flags */
+	unsigned long	mask_s_flags;	/* Bits changed in s_flags */
+	unsigned int	vals_s_mount_opt;
+	unsigned int	mask_s_mount_opt;
+	kuid_t		s_resuid;
+	kgid_t		s_resgid;
+	unsigned long	s_sb_block;
+	unsigned int	spec;
+
+};
+
+static inline void ctx_set_mount_opt(struct ext2_fs_context *ctx,
+				  unsigned long flag)
 {
-	char *p;
-	substring_t args[MAX_OPT_ARGS];
-	int option;
-	kuid_t uid;
-	kgid_t gid;
-
-	if (!options)
-		return 1;
-
-	while ((p = strsep (&options, ",")) != NULL) {
-		int token;
-		if (!*p)
-			continue;
-
-		token = match_token(p, tokens, args);
-		switch (token) {
-		case Opt_bsd_df:
-			clear_opt (opts->s_mount_opt, MINIX_DF);
-			break;
-		case Opt_minix_df:
-			set_opt (opts->s_mount_opt, MINIX_DF);
-			break;
-		case Opt_grpid:
-			set_opt (opts->s_mount_opt, GRPID);
-			break;
-		case Opt_nogrpid:
-			clear_opt (opts->s_mount_opt, GRPID);
-			break;
-		case Opt_resuid:
-			if (match_int(&args[0], &option))
-				return 0;
-			uid = make_kuid(current_user_ns(), option);
-			if (!uid_valid(uid)) {
-				ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
-				return 0;
-
-			}
-			opts->s_resuid = uid;
-			break;
-		case Opt_resgid:
-			if (match_int(&args[0], &option))
-				return 0;
-			gid = make_kgid(current_user_ns(), option);
-			if (!gid_valid(gid)) {
-				ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
-				return 0;
-			}
-			opts->s_resgid = gid;
-			break;
-		case Opt_sb:
-			/* handled by get_sb_block() instead of here */
-			/* *sb_block = match_int(&args[0]); */
-			break;
-		case Opt_err_panic:
-			clear_opt (opts->s_mount_opt, ERRORS_CONT);
-			clear_opt (opts->s_mount_opt, ERRORS_RO);
-			set_opt (opts->s_mount_opt, ERRORS_PANIC);
-			break;
-		case Opt_err_ro:
-			clear_opt (opts->s_mount_opt, ERRORS_CONT);
-			clear_opt (opts->s_mount_opt, ERRORS_PANIC);
-			set_opt (opts->s_mount_opt, ERRORS_RO);
-			break;
-		case Opt_err_cont:
-			clear_opt (opts->s_mount_opt, ERRORS_RO);
-			clear_opt (opts->s_mount_opt, ERRORS_PANIC);
-			set_opt (opts->s_mount_opt, ERRORS_CONT);
-			break;
-		case Opt_nouid32:
-			set_opt (opts->s_mount_opt, NO_UID32);
-			break;
-		case Opt_nocheck:
-			ext2_msg(sb, KERN_WARNING,
-				"Option nocheck/check=none is deprecated and"
-				" will be removed in June 2020.");
-			clear_opt (opts->s_mount_opt, CHECK);
-			break;
-		case Opt_debug:
-			set_opt (opts->s_mount_opt, DEBUG);
-			break;
-		case Opt_oldalloc:
-			set_opt (opts->s_mount_opt, OLDALLOC);
-			break;
-		case Opt_orlov:
-			clear_opt (opts->s_mount_opt, OLDALLOC);
-			break;
-		case Opt_nobh:
-			set_opt (opts->s_mount_opt, NOBH);
-			break;
+	ctx->mask_s_mount_opt |= flag;
+	ctx->vals_s_mount_opt |= flag;
+}
+
+static inline void ctx_clear_mount_opt(struct ext2_fs_context *ctx,
+				    unsigned long flag)
+{
+	ctx->mask_s_mount_opt |= flag;
+	ctx->vals_s_mount_opt &= ~flag;
+}
+
+static inline unsigned long
+ctx_test_mount_opt(struct ext2_fs_context *ctx, unsigned long flag)
+{
+	return (ctx->vals_s_mount_opt & flag);
+}
+
+static inline bool
+ctx_parsed_mount_opt(struct ext2_fs_context *ctx, unsigned long flag)
+{
+	return (ctx->mask_s_mount_opt & flag);
+}
+
+static void ext2_free_fc(struct fs_context *fc)
+{
+	kfree(fc->fs_private);
+}
+
+static int ext2_parse_param(struct fs_context *fc, struct fs_parameter *param)
+{
+	struct ext2_fs_context *ctx = fc->fs_private;
+	int opt;
+	struct fs_parse_result result;
+
+	opt = fs_parse(fc, ext2_param_spec, param, &result);
+	if (opt < 0)
+		return opt;
+
+	switch (opt) {
+	case Opt_bsd_df:
+		ctx_clear_mount_opt(ctx, EXT2_MOUNT_MINIX_DF);
+		break;
+	case Opt_minix_df:
+		ctx_set_mount_opt(ctx, EXT2_MOUNT_MINIX_DF);
+		break;
+	case Opt_grpid:
+		ctx_set_mount_opt(ctx, EXT2_MOUNT_GRPID);
+		break;
+	case Opt_nogrpid:
+		ctx_clear_mount_opt(ctx, EXT2_MOUNT_GRPID);
+		break;
+	case Opt_resuid:
+		ctx->s_resuid = result.uid;
+		ctx->spec |= EXT2_SPEC_s_resuid;
+		break;
+	case Opt_resgid:
+		ctx->s_resgid = result.gid;
+		ctx->spec |= EXT2_SPEC_s_resgid;
+		break;
+	case Opt_sb:
+		/* Note that this is silently ignored on remount */
+		ctx->s_sb_block = result.uint_32;
+		break;
+	case Opt_errors:
+		ctx_clear_mount_opt(ctx, EXT2_MOUNT_ERRORS_MASK);
+		ctx_set_mount_opt(ctx, result.uint_32);
+		break;
+	case Opt_nouid32:
+		ctx_set_mount_opt(ctx, EXT2_MOUNT_NO_UID32);
+		break;
+	case Opt_debug:
+		ctx_set_mount_opt(ctx, EXT2_MOUNT_DEBUG);
+		break;
+	case Opt_oldalloc:
+		ctx_set_mount_opt(ctx, EXT2_MOUNT_OLDALLOC);
+		break;
+	case Opt_orlov:
+		ctx_clear_mount_opt(ctx, EXT2_MOUNT_OLDALLOC);
+		break;
+	case Opt_nobh:
+		ext2_msg_fc(fc, KERN_INFO, "nobh option not supported\n");
+		break;
 #ifdef CONFIG_EXT2_FS_XATTR
-		case Opt_user_xattr:
-			set_opt (opts->s_mount_opt, XATTR_USER);
-			break;
-		case Opt_nouser_xattr:
-			clear_opt (opts->s_mount_opt, XATTR_USER);
-			break;
+	case Opt_user_xattr:
+		if (!result.negated)
+			ctx_set_mount_opt(ctx, EXT2_MOUNT_XATTR_USER);
+		else
+			ctx_clear_mount_opt(ctx, EXT2_MOUNT_XATTR_USER);
+		break;
 #else
-		case Opt_user_xattr:
-		case Opt_nouser_xattr:
-			ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
-				"not supported");
-			break;
+	case Opt_user_xattr:
+		ext2_msg_fc(fc, KERN_INFO, "(no)user_xattr options not supported");
+		break;
 #endif
 #ifdef CONFIG_EXT2_FS_POSIX_ACL
-		case Opt_acl:
-			set_opt(opts->s_mount_opt, POSIX_ACL);
-			break;
-		case Opt_noacl:
-			clear_opt(opts->s_mount_opt, POSIX_ACL);
-			break;
+	case Opt_acl:
+		if (!result.negated)
+			ctx_set_mount_opt(ctx, EXT2_MOUNT_POSIX_ACL);
+		else
+			ctx_clear_mount_opt(ctx, EXT2_MOUNT_POSIX_ACL);
+		break;
 #else
-		case Opt_acl:
-		case Opt_noacl:
-			ext2_msg(sb, KERN_INFO,
-				"(no)acl options not supported");
-			break;
+	case Opt_acl:
+		ext2_msg_fc(fc, KERN_INFO, "(no)acl options not supported");
+		break;
 #endif
-		case Opt_xip:
-			ext2_msg(sb, KERN_INFO, "use dax instead of xip");
-			set_opt(opts->s_mount_opt, XIP);
-			/* Fall through */
-		case Opt_dax:
+	case Opt_xip:
+		ext2_msg_fc(fc, KERN_INFO, "use dax instead of xip");
+		ctx_set_mount_opt(ctx, EXT2_MOUNT_XIP);
+		fallthrough;
+	case Opt_dax:
 #ifdef CONFIG_FS_DAX
-			ext2_msg(sb, KERN_WARNING,
-		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
-			set_opt(opts->s_mount_opt, DAX);
+		ext2_msg_fc(fc, KERN_WARNING,
+		    "DAX enabled. Warning: DAX support in ext2 driver is deprecated"
+		    " and will be removed at the end of 2025. Please use ext4 driver instead.");
+		ctx_set_mount_opt(ctx, EXT2_MOUNT_DAX);
 #else
-			ext2_msg(sb, KERN_INFO, "dax option not supported");
+		ext2_msg_fc(fc, KERN_INFO, "dax option not supported");
 #endif
-			break;
+		break;
 
 #if defined(CONFIG_QUOTA)
-		case Opt_quota:
-		case Opt_usrquota:
-			set_opt(opts->s_mount_opt, USRQUOTA);
-			break;
-
-		case Opt_grpquota:
-			set_opt(opts->s_mount_opt, GRPQUOTA);
-			break;
+	case Opt_quota:
+	case Opt_usrquota:
+		ctx_set_mount_opt(ctx, EXT2_MOUNT_USRQUOTA);
+		break;
+
+	case Opt_grpquota:
+		ctx_set_mount_opt(ctx, EXT2_MOUNT_GRPQUOTA);
+		break;
 #else
-		case Opt_quota:
-		case Opt_usrquota:
-		case Opt_grpquota:
-			ext2_msg(sb, KERN_INFO,
-				"quota operations not supported");
-			break;
+	case Opt_quota:
+	case Opt_usrquota:
+	case Opt_grpquota:
+		ext2_msg_fc(fc, KERN_INFO, "quota operations not supported");
+		break;
 #endif
-
-		case Opt_reservation:
-			set_opt(opts->s_mount_opt, RESERVATION);
-			ext2_msg(sb, KERN_INFO, "reservations ON");
-			break;
-		case Opt_noreservation:
-			clear_opt(opts->s_mount_opt, RESERVATION);
-			ext2_msg(sb, KERN_INFO, "reservations OFF");
-			break;
-		case Opt_ignore:
-			break;
-		default:
-			return 0;
+	case Opt_reservation:
+		if (!result.negated) {
+			ctx_set_mount_opt(ctx, EXT2_MOUNT_RESERVATION);
+			ext2_msg_fc(fc, KERN_INFO, "reservations ON");
+		} else {
+			ctx_clear_mount_opt(ctx, EXT2_MOUNT_RESERVATION);
+			ext2_msg_fc(fc, KERN_INFO, "reservations OFF");
 		}
+		break;
+	case Opt_ignore:
+		break;
+	default:
+		return -EINVAL;
 	}
-	return 1;
+	return 0;
 }
 
 static int ext2_setup_super (struct super_block * sb,
@@ -681,10 +682,9 @@ static int ext2_setup_super (struct super_block * sb,
 		es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
 	le16_add_cpu(&es->s_mnt_count, 1);
 	if (test_opt (sb, DEBUG))
-		ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
+		ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, gc=%lu, "
 			"bpg=%lu, ipg=%lu, mo=%04lx]",
 			EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
-			sbi->s_frag_size,
 			sbi->s_groups_count,
 			EXT2_BLOCKS_PER_GROUP(sb),
 			EXT2_INODES_PER_GROUP(sb),
@@ -764,8 +764,12 @@ static loff_t ext2_max_size(int bits)
 	res += 1LL << (bits-2);
 	res += 1LL << (2*(bits-2));
 	res += 1LL << (3*(bits-2));
+	/* Compute how many metadata blocks are needed */
+	meta_blocks = 1;
+	meta_blocks += 1 + ppb;
+	meta_blocks += 1 + ppb + ppb * ppb;
 	/* Does block tree limit file size? */
-	if (res < upper_limit)
+	if (res + meta_blocks <= upper_limit)
 		goto check_lfs;
 
 	res = upper_limit;
@@ -811,39 +815,98 @@ static unsigned long descriptor_loc(struct super_block *sb,
 	return ext2_group_first_block_no(sb, bg) + ext2_bg_has_super(sb, bg);
 }
 
-static int ext2_fill_super(struct super_block *sb, void *data, int silent)
+/*
+ * Set all mount options either from defaults on disk, or from parsed
+ * options. Parsed/specified options override on-disk defaults.
+ */
+static void ext2_set_options(struct fs_context *fc, struct ext2_sb_info *sbi)
+{
+	struct ext2_fs_context *ctx = fc->fs_private;
+	struct ext2_super_block *es = sbi->s_es;
+	unsigned long def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
+
+	/* Copy parsed mount options to sbi */
+	sbi->s_mount_opt = ctx->vals_s_mount_opt;
+
+	/* Use in-superblock defaults only if not specified during parsing */
+	if (!ctx_parsed_mount_opt(ctx, EXT2_MOUNT_DEBUG) &&
+	    def_mount_opts & EXT2_DEFM_DEBUG)
+		set_opt(sbi->s_mount_opt, DEBUG);
+
+	if (!ctx_parsed_mount_opt(ctx, EXT2_MOUNT_GRPID) &&
+	    def_mount_opts & EXT2_DEFM_BSDGROUPS)
+		set_opt(sbi->s_mount_opt, GRPID);
+
+	if (!ctx_parsed_mount_opt(ctx, EXT2_MOUNT_NO_UID32) &&
+	    def_mount_opts & EXT2_DEFM_UID16)
+		set_opt(sbi->s_mount_opt, NO_UID32);
+
+#ifdef CONFIG_EXT2_FS_XATTR
+	if (!ctx_parsed_mount_opt(ctx, EXT2_MOUNT_XATTR_USER) &&
+	    def_mount_opts & EXT2_DEFM_XATTR_USER)
+		set_opt(sbi->s_mount_opt, XATTR_USER);
+#endif
+#ifdef CONFIG_EXT2_FS_POSIX_ACL
+	if (!ctx_parsed_mount_opt(ctx, EXT2_MOUNT_POSIX_ACL) &&
+	    def_mount_opts & EXT2_DEFM_ACL)
+		set_opt(sbi->s_mount_opt, POSIX_ACL);
+#endif
+
+	if (!ctx_parsed_mount_opt(ctx, EXT2_MOUNT_ERRORS_MASK)) {
+		if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
+			set_opt(sbi->s_mount_opt, ERRORS_PANIC);
+		else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
+			set_opt(sbi->s_mount_opt, ERRORS_CONT);
+		else
+			set_opt(sbi->s_mount_opt, ERRORS_RO);
+	}
+
+	if (ctx->spec & EXT2_SPEC_s_resuid)
+		sbi->s_resuid = ctx->s_resuid;
+	else
+		sbi->s_resuid = make_kuid(&init_user_ns,
+					   le16_to_cpu(es->s_def_resuid));
+
+	if (ctx->spec & EXT2_SPEC_s_resgid)
+		sbi->s_resgid = ctx->s_resgid;
+	else
+		sbi->s_resgid = make_kgid(&init_user_ns,
+					   le16_to_cpu(es->s_def_resgid));
+}
+
+static int ext2_fill_super(struct super_block *sb, struct fs_context *fc)
 {
-	struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
+	struct ext2_fs_context *ctx = fc->fs_private;
+	int silent = fc->sb_flags & SB_SILENT;
 	struct buffer_head * bh;
 	struct ext2_sb_info * sbi;
 	struct ext2_super_block * es;
 	struct inode *root;
 	unsigned long block;
-	unsigned long sb_block = get_sb_block(&data);
+	unsigned long sb_block = ctx->s_sb_block;
 	unsigned long logic_sb_block;
 	unsigned long offset = 0;
-	unsigned long def_mount_opts;
 	long ret = -ENOMEM;
 	int blocksize = BLOCK_SIZE;
 	int db_count;
 	int i, j;
 	__le32 features;
 	int err;
-	struct ext2_mount_options opts;
 
 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 	if (!sbi)
-		goto failed;
+		return -ENOMEM;
 
 	sbi->s_blockgroup_lock =
 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
 	if (!sbi->s_blockgroup_lock) {
 		kfree(sbi);
-		goto failed;
+		return -ENOMEM;
 	}
 	sb->s_fs_info = sbi;
 	sbi->s_sb_block = sb_block;
-	sbi->s_daxdev = dax_dev;
+	sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->s_dax_part_off,
+					   NULL, NULL);
 
 	spin_lock_init(&sbi->s_lock);
 	ret = -EINVAL;
@@ -887,42 +950,7 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 	if (sb->s_magic != EXT2_SUPER_MAGIC)
 		goto cantfind_ext2;
 
-	opts.s_mount_opt = 0;
-	/* Set defaults before we parse the mount options */
-	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
-	if (def_mount_opts & EXT2_DEFM_DEBUG)
-		set_opt(opts.s_mount_opt, DEBUG);
-	if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
-		set_opt(opts.s_mount_opt, GRPID);
-	if (def_mount_opts & EXT2_DEFM_UID16)
-		set_opt(opts.s_mount_opt, NO_UID32);
-#ifdef CONFIG_EXT2_FS_XATTR
-	if (def_mount_opts & EXT2_DEFM_XATTR_USER)
-		set_opt(opts.s_mount_opt, XATTR_USER);
-#endif
-#ifdef CONFIG_EXT2_FS_POSIX_ACL
-	if (def_mount_opts & EXT2_DEFM_ACL)
-		set_opt(opts.s_mount_opt, POSIX_ACL);
-#endif
-	
-	if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
-		set_opt(opts.s_mount_opt, ERRORS_PANIC);
-	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
-		set_opt(opts.s_mount_opt, ERRORS_CONT);
-	else
-		set_opt(opts.s_mount_opt, ERRORS_RO);
-
-	opts.s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
-	opts.s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
-	
-	set_opt(opts.s_mount_opt, RESERVATION);
-
-	if (!parse_options((char *) data, sb, &opts))
-		goto failed_mount;
-
-	sbi->s_mount_opt = opts.s_mount_opt;
-	sbi->s_resuid = opts.s_resuid;
-	sbi->s_resgid = opts.s_resgid;
+	ext2_set_options(fc, sbi);
 
 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
@@ -954,13 +982,23 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 		goto failed_mount;
 	}
 
+	if (le32_to_cpu(es->s_log_block_size) >
+	    (EXT2_MAX_BLOCK_LOG_SIZE - BLOCK_SIZE_BITS)) {
+		ext2_msg(sb, KERN_ERR,
+			 "Invalid log block size: %u",
+			 le32_to_cpu(es->s_log_block_size));
+		goto failed_mount;
+	}
 	blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
 
 	if (test_opt(sb, DAX)) {
-		if (!bdev_dax_supported(sb->s_bdev, blocksize)) {
+		if (!sbi->s_daxdev) {
 			ext2_msg(sb, KERN_ERR,
 				"DAX unsupported by block device. Turning off DAX.");
 			clear_opt(sbi->s_mount_opt, DAX);
+		} else if (blocksize != PAGE_SIZE) {
+			ext2_msg(sb, KERN_ERR, "unsupported blocksize for DAX\n");
+			clear_opt(sbi->s_mount_opt, DAX);
 		}
 	}
 
@@ -1011,14 +1049,7 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 		}
 	}
 
-	sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
-				   le32_to_cpu(es->s_log_frag_size);
-	if (sbi->s_frag_size == 0)
-		goto cantfind_ext2;
-	sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
-
 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
-	sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
 
 	sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
@@ -1044,11 +1075,10 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 		goto failed_mount;
 	}
 
-	if (sb->s_blocksize != sbi->s_frag_size) {
+	if (es->s_log_frag_size != es->s_log_block_size) {
 		ext2_msg(sb, KERN_ERR,
-			"error: fragsize %lu != blocksize %lu"
-			"(not supported yet)",
-			sbi->s_frag_size, sb->s_blocksize);
+			"error: fragsize log %u != blocksize log %u",
+			le32_to_cpu(es->s_log_frag_size), sb->s_blocksize_bits);
 		goto failed_mount;
 	}
 
@@ -1058,27 +1088,41 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 			sbi->s_blocks_per_group);
 		goto failed_mount;
 	}
-	if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
+	/* At least inode table, bitmaps, and sb have to fit in one group */
+	if (sbi->s_blocks_per_group <= sbi->s_itb_per_group + 3) {
 		ext2_msg(sb, KERN_ERR,
-			"error: #fragments per group too big: %lu",
-			sbi->s_frags_per_group);
+			"error: #blocks per group smaller than metadata size: %lu <= %lu",
+			sbi->s_blocks_per_group, sbi->s_inodes_per_group + 3);
 		goto failed_mount;
 	}
-	if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
+	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
+	    sbi->s_inodes_per_group > sb->s_blocksize * 8) {
 		ext2_msg(sb, KERN_ERR,
-			"error: #inodes per group too big: %lu",
+			"error: invalid #inodes per group: %lu",
 			sbi->s_inodes_per_group);
 		goto failed_mount;
 	}
+	if (sb_bdev_nr_blocks(sb) < le32_to_cpu(es->s_blocks_count)) {
+		ext2_msg(sb, KERN_ERR,
+			 "bad geometry: block count %u exceeds size of device (%u blocks)",
+			 le32_to_cpu(es->s_blocks_count),
+			 (unsigned)sb_bdev_nr_blocks(sb));
+		goto failed_mount;
+	}
 
-	if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
-		goto cantfind_ext2;
 	sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
 				le32_to_cpu(es->s_first_data_block) - 1)
 					/ EXT2_BLOCKS_PER_GROUP(sb)) + 1;
+	if ((u64)sbi->s_groups_count * sbi->s_inodes_per_group !=
+	    le32_to_cpu(es->s_inodes_count)) {
+		ext2_msg(sb, KERN_ERR, "error: invalid #inodes: %u vs computed %llu",
+			 le32_to_cpu(es->s_inodes_count),
+			 (u64)sbi->s_groups_count * sbi->s_inodes_per_group);
+		goto failed_mount;
+	}
 	db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
 		   EXT2_DESC_PER_BLOCK(sb);
-	sbi->s_group_desc = kmalloc_array (db_count,
+	sbi->s_group_desc = kvmalloc_array(db_count,
 					   sizeof(struct buffer_head *),
 					   GFP_KERNEL);
 	if (sbi->s_group_desc == NULL) {
@@ -1112,7 +1156,7 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
 	spin_lock_init(&sbi->s_next_gen_lock);
 
-	/* per fileystem reservation list head & lock */
+	/* per filesystem reservation list head & lock */
 	spin_lock_init(&sbi->s_rsv_window_lock);
 	sbi->s_rsv_window_root = RB_ROOT;
 	/*
@@ -1204,16 +1248,15 @@ failed_mount2:
 	for (i = 0; i < db_count; i++)
 		brelse(sbi->s_group_desc[i]);
 failed_mount_group_desc:
-	kfree(sbi->s_group_desc);
+	kvfree(sbi->s_group_desc);
 	kfree(sbi->s_debts);
 failed_mount:
 	brelse(bh);
 failed_sbi:
+	fs_put_dax(sbi->s_daxdev, NULL);
 	sb->s_fs_info = NULL;
 	kfree(sbi->s_blockgroup_lock);
 	kfree(sbi);
-failed:
-	fs_put_dax(dax_dev);
 	return ret;
 }
 
@@ -1319,23 +1362,21 @@ static void ext2_write_super(struct super_block *sb)
 		ext2_sync_fs(sb, 1);
 }
 
-static int ext2_remount (struct super_block * sb, int * flags, char * data)
+static int ext2_reconfigure(struct fs_context *fc)
 {
+	struct ext2_fs_context *ctx = fc->fs_private;
+	struct super_block *sb = fc->root->d_sb;
 	struct ext2_sb_info * sbi = EXT2_SB(sb);
 	struct ext2_super_block * es;
 	struct ext2_mount_options new_opts;
+	int flags = fc->sb_flags;
 	int err;
 
 	sync_filesystem(sb);
 
-	spin_lock(&sbi->s_lock);
-	new_opts.s_mount_opt = sbi->s_mount_opt;
-	new_opts.s_resuid = sbi->s_resuid;
-	new_opts.s_resgid = sbi->s_resgid;
-	spin_unlock(&sbi->s_lock);
-
-	if (!parse_options(data, sb, &new_opts))
-		return -EINVAL;
+	new_opts.s_mount_opt = ctx->vals_s_mount_opt;
+	new_opts.s_resuid = ctx->s_resuid;
+	new_opts.s_resgid = ctx->s_resgid;
 
 	spin_lock(&sbi->s_lock);
 	es = sbi->s_es;
@@ -1344,9 +1385,9 @@ static int ext2_remount (struct super_block * sb, int * flags, char * data)
 			 "dax flag with busy inodes while remounting");
 		new_opts.s_mount_opt ^= EXT2_MOUNT_DAX;
 	}
-	if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
+	if ((bool)(flags & SB_RDONLY) == sb_rdonly(sb))
 		goto out_set;
-	if (*flags & SB_RDONLY) {
+	if (flags & SB_RDONLY) {
 		if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
 		    !(sbi->s_mount_state & EXT2_VALID_FS))
 			goto out_set;
@@ -1407,7 +1448,6 @@ static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
 	struct super_block *sb = dentry->d_sb;
 	struct ext2_sb_info *sbi = EXT2_SB(sb);
 	struct ext2_super_block *es = sbi->s_es;
-	u64 fsid;
 
 	spin_lock(&sbi->s_lock);
 
@@ -1461,18 +1501,14 @@ static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
 	buf->f_ffree = ext2_count_free_inodes(sb);
 	es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
 	buf->f_namelen = EXT2_NAME_LEN;
-	fsid = le64_to_cpup((void *)es->s_uuid) ^
-	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
-	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
-	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
+	buf->f_fsid = uuid_to_fsid(es->s_uuid);
 	spin_unlock(&sbi->s_lock);
 	return 0;
 }
 
-static struct dentry *ext2_mount(struct file_system_type *fs_type,
-	int flags, const char *dev_name, void *data)
+static int ext2_get_tree(struct fs_context *fc)
 {
-	return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
+	return get_tree_bdev(fc, ext2_fill_super);
 }
 
 #ifdef CONFIG_QUOTA
@@ -1500,8 +1536,7 @@ static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
 		len = i_size-off;
 	toread = len;
 	while (toread > 0) {
-		tocopy = sb->s_blocksize - offset < toread ?
-				sb->s_blocksize - offset : toread;
+		tocopy = min_t(size_t, sb->s_blocksize - offset, toread);
 
 		tmp_bh.b_state = 0;
 		tmp_bh.b_size = sb->s_blocksize;
@@ -1539,8 +1574,7 @@ static ssize_t ext2_quota_write(struct super_block *sb, int type,
 	struct buffer_head *bh;
 
 	while (towrite > 0) {
-		tocopy = sb->s_blocksize - offset < towrite ?
-				sb->s_blocksize - offset : towrite;
+		tocopy = min_t(size_t, sb->s_blocksize - offset, towrite);
 
 		tmp_bh.b_state = 0;
 		tmp_bh.b_size = sb->s_blocksize;
@@ -1557,7 +1591,7 @@ static ssize_t ext2_quota_write(struct super_block *sb, int type,
 		}
 		lock_buffer(bh);
 		memcpy(bh->b_data+offset, data, tocopy);
-		flush_dcache_page(bh->b_page);
+		flush_dcache_folio(bh->b_folio);
 		set_buffer_uptodate(bh);
 		mark_buffer_dirty(bh);
 		unlock_buffer(bh);
@@ -1573,7 +1607,7 @@ out:
 	if (inode->i_size < off+len-towrite)
 		i_size_write(inode, off+len-towrite);
 	inode_inc_iversion(inode);
-	inode->i_mtime = inode->i_ctime = current_time(inode);
+	inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
 	mark_inode_dirty(inode);
 	return len - towrite;
 }
@@ -1625,12 +1659,49 @@ out:
 
 #endif
 
+static const struct fs_context_operations ext2_context_ops = {
+	.parse_param	= ext2_parse_param,
+	.get_tree	= ext2_get_tree,
+	.reconfigure	= ext2_reconfigure,
+	.free		= ext2_free_fc,
+};
+
+static int ext2_init_fs_context(struct fs_context *fc)
+{
+	struct ext2_fs_context *ctx;
+
+	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
+		struct super_block *sb = fc->root->d_sb;
+		struct ext2_sb_info *sbi = EXT2_SB(sb);
+
+		spin_lock(&sbi->s_lock);
+		ctx->vals_s_mount_opt = sbi->s_mount_opt;
+		ctx->vals_s_flags = sb->s_flags;
+		ctx->s_resuid = sbi->s_resuid;
+		ctx->s_resgid = sbi->s_resgid;
+		spin_unlock(&sbi->s_lock);
+	} else {
+		ctx->s_sb_block = 1;
+		ctx_set_mount_opt(ctx, EXT2_MOUNT_RESERVATION);
+	}
+
+	fc->fs_private = ctx;
+	fc->ops = &ext2_context_ops;
+
+	return 0;
+}
+
 static struct file_system_type ext2_fs_type = {
 	.owner		= THIS_MODULE,
 	.name		= "ext2",
-	.mount		= ext2_mount,
 	.kill_sb	= kill_block_super,
 	.fs_flags	= FS_REQUIRES_DEV,
+	.init_fs_context = ext2_init_fs_context,
+	.parameters	= ext2_param_spec,
 };
 MODULE_ALIAS_FS("ext2");
 
@@ -1641,7 +1712,7 @@ static int __init init_ext2_fs(void)
 	err = init_inodecache();
 	if (err)
 		return err;
-        err = register_filesystem(&ext2_fs_type);
+	err = register_filesystem(&ext2_fs_type);
 	if (err)
 		goto out;
 	return 0;