Re: [PATCH V2 2/3] fat: Convert to new mount api

[OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>]

Forgot Cc

OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> writes:

> Eric Sandeen <sandeen@redhat.com> writes:
>
>> vfat and msdos share a common set of options, with additional, unique
>> options for each filesystem.
>>
>> Each filesystem calls common fc initialization and parsing routines,
>> with an "is_vfat" parameter. For parsing, if the option is not found
>> in the common parameter_spec, parsing is retried with the fs-specific
>> parameter_spec.
>>
>> This patch leaves nls loading to fill_super, so the codepage and charset
>> options are not validated as they are requested. This matches current
>> behavior. It would be possible to test-load as each option is parsed,
>> but that would make i.e.
>>
>> mount -o "iocharset=nope,iocharset=iso8859-1"
>>
>> fail, where it does not fail today because only the last iocharset
>> option is considered.
>>
>> The obsolete "conv=" option is set up with an enum of acceptable values;
>> currently invalid "conv=" options are rejected as such, even though the
>> option is obsolete, so this patch preserves that behavior.
>>
>> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
>
> Looks good.
>
> Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
>
> Thanks.
>
>> ---
>>
>> V2: address review comments:
>>
>> - remove unused buf variable in fat_parse_param
>> - remove unnecessary externs in new prototypes
>> - mark deprecated options with fs_param_deprecated
>> - fix double-free of opts->codepage
>> - change is_vfat parameters to boolsw
>>
>>  fs/fat/fat.h         |  15 +-
>>  fs/fat/inode.c       | 683 ++++++++++++++++++++++---------------------
>>  fs/fat/namei_msdos.c |  38 ++-
>>  fs/fat/namei_vfat.c  |  38 ++-
>>  4 files changed, 419 insertions(+), 355 deletions(-)
>>
>> diff --git a/fs/fat/fat.h b/fs/fat/fat.h
>> index 37ced7bb06d5..d3e426de5f01 100644
>> --- a/fs/fat/fat.h
>> +++ b/fs/fat/fat.h
>> @@ -7,6 +7,8 @@
>>  #include <linux/hash.h>
>>  #include <linux/ratelimit.h>
>>  #include <linux/msdos_fs.h>
>> +#include <linux/fs_context.h>
>> +#include <linux/fs_parser.h>
>>  
>>  /*
>>   * vfat shortname flags
>> @@ -416,12 +418,21 @@ extern struct inode *fat_iget(struct super_block *sb, loff_t i_pos);
>>  extern struct inode *fat_build_inode(struct super_block *sb,
>>  			struct msdos_dir_entry *de, loff_t i_pos);
>>  extern int fat_sync_inode(struct inode *inode);
>> -extern int fat_fill_super(struct super_block *sb, void *data, int silent,
>> -			  int isvfat, void (*setup)(struct super_block *));
>> +extern int fat_fill_super(struct super_block *sb, struct fs_context *fc,
>> +			  void (*setup)(struct super_block *));
>>  extern int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de);
>>  
>>  extern int fat_flush_inodes(struct super_block *sb, struct inode *i1,
>>  			    struct inode *i2);
>> +
>> +extern const struct fs_parameter_spec fat_param_spec[];
>> +int fat_init_fs_context(struct fs_context *fc, bool is_vfat);
>> +void fat_free_fc(struct fs_context *fc);
>> +
>> +int fat_parse_param(struct fs_context *fc, struct fs_parameter *param,
>> +		    bool is_vfat);
>> +int fat_reconfigure(struct fs_context *fc);
>> +
>>  static inline unsigned long fat_dir_hash(int logstart)
>>  {
>>  	return hash_32(logstart, FAT_HASH_BITS);
>> diff --git a/fs/fat/inode.c b/fs/fat/inode.c
>> index 2a6537ba0d49..b83b39f2f69b 100644
>> --- a/fs/fat/inode.c
>> +++ b/fs/fat/inode.c
>> @@ -16,7 +16,6 @@
>>  #include <linux/mpage.h>
>>  #include <linux/vfs.h>
>>  #include <linux/seq_file.h>
>> -#include <linux/parser.h>
>>  #include <linux/uio.h>
>>  #include <linux/blkdev.h>
>>  #include <linux/backing-dev.h>
>> @@ -804,16 +803,17 @@ static void __exit fat_destroy_inodecache(void)
>>  	kmem_cache_destroy(fat_inode_cachep);
>>  }
>>  
>> -static int fat_remount(struct super_block *sb, int *flags, char *data)
>> +int fat_reconfigure(struct fs_context *fc)
>>  {
>>  	bool new_rdonly;
>> +	struct super_block *sb = fc->root->d_sb;
>>  	struct msdos_sb_info *sbi = MSDOS_SB(sb);
>> -	*flags |= SB_NODIRATIME | (sbi->options.isvfat ? 0 : SB_NOATIME);
>> +	fc->sb_flags |= SB_NODIRATIME | (sbi->options.isvfat ? 0 : SB_NOATIME);
>>  
>>  	sync_filesystem(sb);
>>  
>>  	/* make sure we update state on remount. */
>> -	new_rdonly = *flags & SB_RDONLY;
>> +	new_rdonly = fc->sb_flags & SB_RDONLY;
>>  	if (new_rdonly != sb_rdonly(sb)) {
>>  		if (new_rdonly)
>>  			fat_set_state(sb, 0, 0);
>> @@ -822,6 +822,7 @@ static int fat_remount(struct super_block *sb, int *flags, char *data)
>>  	}
>>  	return 0;
>>  }
>> +EXPORT_SYMBOL_GPL(fat_reconfigure);
>>  
>>  static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
>>  {
>> @@ -939,8 +940,6 @@ static const struct super_operations fat_sops = {
>>  	.evict_inode	= fat_evict_inode,
>>  	.put_super	= fat_put_super,
>>  	.statfs		= fat_statfs,
>> -	.remount_fs	= fat_remount,
>> -
>>  	.show_options	= fat_show_options,
>>  };
>>  
>> @@ -1037,355 +1036,290 @@ static int fat_show_options(struct seq_file *m, struct dentry *root)
>>  }
>>  
>>  enum {
>> -	Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
>> -	Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage,
>> -	Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug,
>> -	Opt_immutable, Opt_dots, Opt_nodots,
>> -	Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
>> -	Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
>> -	Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
>> -	Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont,
>> -	Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset,
>> -	Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err, Opt_dos1xfloppy,
>> +	Opt_check, Opt_uid, Opt_gid, Opt_umask, Opt_dmask, Opt_fmask,
>> +	Opt_allow_utime, Opt_codepage, Opt_usefree, Opt_nocase, Opt_quiet,
>> +	Opt_showexec, Opt_debug, Opt_immutable, Opt_dots, Opt_dotsOK,
>> +	Opt_charset, Opt_shortname, Opt_utf8, Opt_utf8_bool,
>> +	Opt_uni_xl, Opt_uni_xl_bool, Opt_nonumtail, Opt_nonumtail_bool,
>> +	Opt_obsolete, Opt_flush, Opt_tz, Opt_rodir, Opt_errors, Opt_discard,
>> +	Opt_nfs, Opt_nfs_enum, Opt_time_offset, Opt_dos1xfloppy,
>>  };
>>  
>> -static const match_table_t fat_tokens = {
>> -	{Opt_check_r, "check=relaxed"},
>> -	{Opt_check_s, "check=strict"},
>> -	{Opt_check_n, "check=normal"},
>> -	{Opt_check_r, "check=r"},
>> -	{Opt_check_s, "check=s"},
>> -	{Opt_check_n, "check=n"},
>> -	{Opt_uid, "uid=%u"},
>> -	{Opt_gid, "gid=%u"},
>> -	{Opt_umask, "umask=%o"},
>> -	{Opt_dmask, "dmask=%o"},
>> -	{Opt_fmask, "fmask=%o"},
>> -	{Opt_allow_utime, "allow_utime=%o"},
>> -	{Opt_codepage, "codepage=%u"},
>> -	{Opt_usefree, "usefree"},
>> -	{Opt_nocase, "nocase"},
>> -	{Opt_quiet, "quiet"},
>> -	{Opt_showexec, "showexec"},
>> -	{Opt_debug, "debug"},
>> -	{Opt_immutable, "sys_immutable"},
>> -	{Opt_flush, "flush"},
>> -	{Opt_tz_utc, "tz=UTC"},
>> -	{Opt_time_offset, "time_offset=%d"},
>> -	{Opt_err_cont, "errors=continue"},
>> -	{Opt_err_panic, "errors=panic"},
>> -	{Opt_err_ro, "errors=remount-ro"},
>> -	{Opt_discard, "discard"},
>> -	{Opt_nfs_stale_rw, "nfs"},
>> -	{Opt_nfs_stale_rw, "nfs=stale_rw"},
>> -	{Opt_nfs_nostale_ro, "nfs=nostale_ro"},
>> -	{Opt_dos1xfloppy, "dos1xfloppy"},
>> -	{Opt_obsolete, "conv=binary"},
>> -	{Opt_obsolete, "conv=text"},
>> -	{Opt_obsolete, "conv=auto"},
>> -	{Opt_obsolete, "conv=b"},
>> -	{Opt_obsolete, "conv=t"},
>> -	{Opt_obsolete, "conv=a"},
>> -	{Opt_obsolete, "fat=%u"},
>> -	{Opt_obsolete, "blocksize=%u"},
>> -	{Opt_obsolete, "cvf_format=%20s"},
>> -	{Opt_obsolete, "cvf_options=%100s"},
>> -	{Opt_obsolete, "posix"},
>> -	{Opt_err, NULL},
>> -};
>> -static const match_table_t msdos_tokens = {
>> -	{Opt_nodots, "nodots"},
>> -	{Opt_nodots, "dotsOK=no"},
>> -	{Opt_dots, "dots"},
>> -	{Opt_dots, "dotsOK=yes"},
>> -	{Opt_err, NULL}
>> -};
>> -static const match_table_t vfat_tokens = {
>> -	{Opt_charset, "iocharset=%s"},
>> -	{Opt_shortname_lower, "shortname=lower"},
>> -	{Opt_shortname_win95, "shortname=win95"},
>> -	{Opt_shortname_winnt, "shortname=winnt"},
>> -	{Opt_shortname_mixed, "shortname=mixed"},
>> -	{Opt_utf8_no, "utf8=0"},		/* 0 or no or false */
>> -	{Opt_utf8_no, "utf8=no"},
>> -	{Opt_utf8_no, "utf8=false"},
>> -	{Opt_utf8_yes, "utf8=1"},		/* empty or 1 or yes or true */
>> -	{Opt_utf8_yes, "utf8=yes"},
>> -	{Opt_utf8_yes, "utf8=true"},
>> -	{Opt_utf8_yes, "utf8"},
>> -	{Opt_uni_xl_no, "uni_xlate=0"},		/* 0 or no or false */
>> -	{Opt_uni_xl_no, "uni_xlate=no"},
>> -	{Opt_uni_xl_no, "uni_xlate=false"},
>> -	{Opt_uni_xl_yes, "uni_xlate=1"},	/* empty or 1 or yes or true */
>> -	{Opt_uni_xl_yes, "uni_xlate=yes"},
>> -	{Opt_uni_xl_yes, "uni_xlate=true"},
>> -	{Opt_uni_xl_yes, "uni_xlate"},
>> -	{Opt_nonumtail_no, "nonumtail=0"},	/* 0 or no or false */
>> -	{Opt_nonumtail_no, "nonumtail=no"},
>> -	{Opt_nonumtail_no, "nonumtail=false"},
>> -	{Opt_nonumtail_yes, "nonumtail=1"},	/* empty or 1 or yes or true */
>> -	{Opt_nonumtail_yes, "nonumtail=yes"},
>> -	{Opt_nonumtail_yes, "nonumtail=true"},
>> -	{Opt_nonumtail_yes, "nonumtail"},
>> -	{Opt_rodir, "rodir"},
>> -	{Opt_err, NULL}
>> +static const struct constant_table fat_param_check[] = {
>> +	{"relaxed",	'r'},
>> +	{"r",		'r'},
>> +	{"strict",	's'},
>> +	{"s",		's'},
>> +	{"normal",	'n'},
>> +	{"n",		'n'},
>> +	{}
>>  };
>>  
>> -static int parse_options(struct super_block *sb, char *options, int is_vfat,
>> -			 int silent, struct fat_mount_options *opts)
>> -{
>> -	char *p;
>> -	substring_t args[MAX_OPT_ARGS];
>> -	int option;
>> -	char *iocharset;
>> +static const struct constant_table fat_param_tz[] = {
>> +	{"UTC",		0},
>> +	{}
>> +};
>>  
>> -	opts->isvfat = is_vfat;
>> +static const struct constant_table fat_param_errors[] = {
>> +	{"continue",	FAT_ERRORS_CONT},
>> +	{"panic",	FAT_ERRORS_PANIC},
>> +	{"remount-ro",	FAT_ERRORS_RO},
>> +	{}
>> +};
>>  
>> -	opts->fs_uid = current_uid();
>> -	opts->fs_gid = current_gid();
>> -	opts->fs_fmask = opts->fs_dmask = current_umask();
>> -	opts->allow_utime = -1;
>> -	opts->codepage = fat_default_codepage;
>> -	fat_reset_iocharset(opts);
>> -	if (is_vfat) {
>> -		opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95;
>> -		opts->rodir = 0;
>> -	} else {
>> -		opts->shortname = 0;
>> -		opts->rodir = 1;
>> -	}
>> -	opts->name_check = 'n';
>> -	opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK =  0;
>> -	opts->unicode_xlate = 0;
>> -	opts->numtail = 1;
>> -	opts->usefree = opts->nocase = 0;
>> -	opts->tz_set = 0;
>> -	opts->nfs = 0;
>> -	opts->errors = FAT_ERRORS_RO;
>> -	opts->debug = 0;
>>  
>> -	opts->utf8 = IS_ENABLED(CONFIG_FAT_DEFAULT_UTF8) && is_vfat;
>> +static const struct constant_table fat_param_nfs[] = {
>> +	{"stale_rw",	FAT_NFS_STALE_RW},
>> +	{"nostale_ro",	FAT_NFS_NOSTALE_RO},
>> +	{}
>> +};
>>  
>> -	if (!options)
>> -		goto out;
>> +/*
>> + * These are all obsolete but we still reject invalid options.
>> + * The corresponding values are therefore meaningless.
>> + */
>> +static const struct constant_table fat_param_conv[] = {
>> +	{"binary",	0},
>> +	{"text",	0},
>> +	{"auto",	0},
>> +	{"b",		0},
>> +	{"t",		0},
>> +	{"a",		0},
>> +	{}
>> +};
>>  
>> -	while ((p = strsep(&options, ",")) != NULL) {
>> -		int token;
>> -		if (!*p)
>> -			continue;
>> +/* Core options. See below for vfat and msdos extras */
>> +const struct fs_parameter_spec fat_param_spec[] = {
>> +	fsparam_enum	("check",	Opt_check, fat_param_check),
>> +	fsparam_u32	("uid",		Opt_uid),
>> +	fsparam_u32	("gid",		Opt_gid),
>> +	fsparam_u32oct	("umask",	Opt_umask),
>> +	fsparam_u32oct	("dmask",	Opt_dmask),
>> +	fsparam_u32oct	("fmask",	Opt_fmask),
>> +	fsparam_u32oct	("allow_utime",	Opt_allow_utime),
>> +	fsparam_u32	("codepage",	Opt_codepage),
>> +	fsparam_flag	("usefree",	Opt_usefree),
>> +	fsparam_flag	("nocase",	Opt_nocase),
>> +	fsparam_flag	("quiet",	Opt_quiet),
>> +	fsparam_flag	("showexec",	Opt_showexec),
>> +	fsparam_flag	("debug",	Opt_debug),
>> +	fsparam_flag	("sys_immutable", Opt_immutable),
>> +	fsparam_flag	("flush",	Opt_flush),
>> +	fsparam_enum	("tz",		Opt_tz, fat_param_tz),
>> +	fsparam_s32	("time_offset",	Opt_time_offset),
>> +	fsparam_enum	("errors",	Opt_errors, fat_param_errors),
>> +	fsparam_flag	("discard",	Opt_discard),
>> +	fsparam_flag	("nfs",		Opt_nfs),
>> +	fsparam_enum	("nfs",		Opt_nfs_enum, fat_param_nfs),
>> +	fsparam_flag	("dos1xfloppy",	Opt_dos1xfloppy),
>> +	__fsparam(fs_param_is_enum,	"conv",
>> +		  Opt_obsolete, fs_param_deprecated, fat_param_conv),
>> +	__fsparam(fs_param_is_u32,	"fat",
>> +		  Opt_obsolete, fs_param_deprecated, NULL),
>> +	__fsparam(fs_param_is_u32,	"blocksize",
>> +		  Opt_obsolete, fs_param_deprecated, NULL),
>> +	__fsparam(fs_param_is_string,	"cvf_format",
>> +		  Opt_obsolete, fs_param_deprecated, NULL),
>> +	__fsparam(fs_param_is_string,	"cvf_options",
>> +		  Opt_obsolete, fs_param_deprecated, NULL),
>> +	__fsparam(NULL,			"posix",
>> +		  Opt_obsolete, fs_param_deprecated, NULL),
>> +	{}
>> +};
>> +EXPORT_SYMBOL_GPL(fat_param_spec);
>>  
>> -		token = match_token(p, fat_tokens, args);
>> -		if (token == Opt_err) {
>> -			if (is_vfat)
>> -				token = match_token(p, vfat_tokens, args);
>> -			else
>> -				token = match_token(p, msdos_tokens, args);
>> -		}
>> -		switch (token) {
>> -		case Opt_check_s:
>> -			opts->name_check = 's';
>> -			break;
>> -		case Opt_check_r:
>> -			opts->name_check = 'r';
>> -			break;
>> -		case Opt_check_n:
>> -			opts->name_check = 'n';
>> -			break;
>> -		case Opt_usefree:
>> -			opts->usefree = 1;
>> -			break;
>> -		case Opt_nocase:
>> -			if (!is_vfat)
>> -				opts->nocase = 1;
>> -			else {
>> -				/* for backward compatibility */
>> -				opts->shortname = VFAT_SFN_DISPLAY_WIN95
>> -					| VFAT_SFN_CREATE_WIN95;
>> -			}
>> -			break;
>> -		case Opt_quiet:
>> -			opts->quiet = 1;
>> -			break;
>> -		case Opt_showexec:
>> -			opts->showexec = 1;
>> -			break;
>> -		case Opt_debug:
>> -			opts->debug = 1;
>> -			break;
>> -		case Opt_immutable:
>> -			opts->sys_immutable = 1;
>> -			break;
>> -		case Opt_uid:
>> -			if (match_int(&args[0], &option))
>> -				return -EINVAL;
>> -			opts->fs_uid = make_kuid(current_user_ns(), option);
>> -			if (!uid_valid(opts->fs_uid))
>> -				return -EINVAL;
>> -			break;
>> -		case Opt_gid:
>> -			if (match_int(&args[0], &option))
>> -				return -EINVAL;
>> -			opts->fs_gid = make_kgid(current_user_ns(), option);
>> -			if (!gid_valid(opts->fs_gid))
>> -				return -EINVAL;
>> -			break;
>> -		case Opt_umask:
>> -			if (match_octal(&args[0], &option))
>> -				return -EINVAL;
>> -			opts->fs_fmask = opts->fs_dmask = option;
>> -			break;
>> -		case Opt_dmask:
>> -			if (match_octal(&args[0], &option))
>> -				return -EINVAL;
>> -			opts->fs_dmask = option;
>> -			break;
>> -		case Opt_fmask:
>> -			if (match_octal(&args[0], &option))
>> -				return -EINVAL;
>> -			opts->fs_fmask = option;
>> -			break;
>> -		case Opt_allow_utime:
>> -			if (match_octal(&args[0], &option))
>> -				return -EINVAL;
>> -			opts->allow_utime = option & (S_IWGRP | S_IWOTH);
>> -			break;
>> -		case Opt_codepage:
>> -			if (match_int(&args[0], &option))
>> -				return -EINVAL;
>> -			opts->codepage = option;
>> -			break;
>> -		case Opt_flush:
>> -			opts->flush = 1;
>> -			break;
>> -		case Opt_time_offset:
>> -			if (match_int(&args[0], &option))
>> -				return -EINVAL;
>> -			/*
>> -			 * GMT+-12 zones may have DST corrections so at least
>> -			 * 13 hours difference is needed. Make the limit 24
>> -			 * just in case someone invents something unusual.
>> -			 */
>> -			if (option < -24 * 60 || option > 24 * 60)
>> -				return -EINVAL;
>> -			opts->tz_set = 1;
>> -			opts->time_offset = option;
>> -			break;
>> -		case Opt_tz_utc:
>> -			opts->tz_set = 1;
>> -			opts->time_offset = 0;
>> -			break;
>> -		case Opt_err_cont:
>> -			opts->errors = FAT_ERRORS_CONT;
>> -			break;
>> -		case Opt_err_panic:
>> -			opts->errors = FAT_ERRORS_PANIC;
>> -			break;
>> -		case Opt_err_ro:
>> -			opts->errors = FAT_ERRORS_RO;
>> -			break;
>> -		case Opt_nfs_stale_rw:
>> -			opts->nfs = FAT_NFS_STALE_RW;
>> -			break;
>> -		case Opt_nfs_nostale_ro:
>> -			opts->nfs = FAT_NFS_NOSTALE_RO;
>> -			break;
>> -		case Opt_dos1xfloppy:
>> -			opts->dos1xfloppy = 1;
>> -			break;
>> +static const struct fs_parameter_spec msdos_param_spec[] = {
>> +	fsparam_flag_no	("dots",	Opt_dots),
>> +	fsparam_bool	("dotsOK",	Opt_dotsOK),
>> +	{}
>> +};
>>  
>> -		/* msdos specific */
>> -		case Opt_dots:
>> -			opts->dotsOK = 1;
>> -			break;
>> -		case Opt_nodots:
>> -			opts->dotsOK = 0;
>> -			break;
>> +static const struct constant_table fat_param_shortname[] = {
>> +	{"lower",	VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95},
>> +	{"win95",	VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95},
>> +	{"winnt",	VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT},
>> +	{"mixed",	VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95},
>> +	{}
>> +};
>>  
>> -		/* vfat specific */
>> -		case Opt_charset:
>> -			fat_reset_iocharset(opts);
>> -			iocharset = match_strdup(&args[0]);
>> -			if (!iocharset)
>> -				return -ENOMEM;
>> -			opts->iocharset = iocharset;
>> -			break;
>> -		case Opt_shortname_lower:
>> -			opts->shortname = VFAT_SFN_DISPLAY_LOWER
>> -					| VFAT_SFN_CREATE_WIN95;
>> -			break;
>> -		case Opt_shortname_win95:
>> -			opts->shortname = VFAT_SFN_DISPLAY_WIN95
>> -					| VFAT_SFN_CREATE_WIN95;
>> -			break;
>> -		case Opt_shortname_winnt:
>> -			opts->shortname = VFAT_SFN_DISPLAY_WINNT
>> -					| VFAT_SFN_CREATE_WINNT;
>> -			break;
>> -		case Opt_shortname_mixed:
>> -			opts->shortname = VFAT_SFN_DISPLAY_WINNT
>> -					| VFAT_SFN_CREATE_WIN95;
>> -			break;
>> -		case Opt_utf8_no:		/* 0 or no or false */
>> -			opts->utf8 = 0;
>> -			break;
>> -		case Opt_utf8_yes:		/* empty or 1 or yes or true */
>> -			opts->utf8 = 1;
>> -			break;
>> -		case Opt_uni_xl_no:		/* 0 or no or false */
>> -			opts->unicode_xlate = 0;
>> -			break;
>> -		case Opt_uni_xl_yes:		/* empty or 1 or yes or true */
>> -			opts->unicode_xlate = 1;
>> -			break;
>> -		case Opt_nonumtail_no:		/* 0 or no or false */
>> -			opts->numtail = 1;	/* negated option */
>> -			break;
>> -		case Opt_nonumtail_yes:		/* empty or 1 or yes or true */
>> -			opts->numtail = 0;	/* negated option */
>> -			break;
>> -		case Opt_rodir:
>> -			opts->rodir = 1;
>> -			break;
>> -		case Opt_discard:
>> -			opts->discard = 1;
>> -			break;
>> +static const struct fs_parameter_spec vfat_param_spec[] = {
>> +	fsparam_string	("iocharset",	Opt_charset),
>> +	fsparam_enum	("shortname",	Opt_shortname, fat_param_shortname),
>> +	fsparam_flag	("utf8",	Opt_utf8),
>> +	fsparam_bool	("utf8",	Opt_utf8_bool),
>> +	fsparam_flag	("uni_xlate",	Opt_uni_xl),
>> +	fsparam_bool	("uni_xlate",	Opt_uni_xl_bool),
>> +	fsparam_flag	("nonumtail",	Opt_nonumtail),
>> +	fsparam_bool	("nonumtail",	Opt_nonumtail_bool),
>> +	fsparam_flag	("rodir",	Opt_rodir),
>> +	{}
>> +};
>>  
>> -		/* obsolete mount options */
>> -		case Opt_obsolete:
>> -			fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, "
>> -			       "not supported now", p);
>> -			break;
>> -		/* unknown option */
>> -		default:
>> -			if (!silent) {
>> -				fat_msg(sb, KERN_ERR,
>> -				       "Unrecognized mount option \"%s\" "
>> -				       "or missing value", p);
>> -			}
>> -			return -EINVAL;
>> -		}
>> -	}
>> +int fat_parse_param(struct fs_context *fc, struct fs_parameter *param,
>> +			   bool is_vfat)
>> +{
>> +	struct fat_mount_options *opts = fc->fs_private;
>> +	struct fs_parse_result result;
>> +	int opt;
>> +	kuid_t uid;
>> +	kgid_t gid;
>> +
>> +	/* remount options have traditionally been ignored */
>> +	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE)
>> +		return 0;
>>  
>> -out:
>> -	/* UTF-8 doesn't provide FAT semantics */
>> -	if (!strcmp(opts->iocharset, "utf8")) {
>> -		fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset"
>> -		       " for FAT filesystems, filesystem will be "
>> -		       "case sensitive!");
>> +	opt = fs_parse(fc, fat_param_spec, param, &result);
>> +	/* If option not found in fat_param_spec, try vfat/msdos options */
>> +	if (opt == -ENOPARAM) {
>> +		if (is_vfat)
>> +			opt = fs_parse(fc, vfat_param_spec, param, &result);
>> +		else
>> +			opt = fs_parse(fc, msdos_param_spec, param, &result);
>>  	}
>>  
>> -	/* If user doesn't specify allow_utime, it's initialized from dmask. */
>> -	if (opts->allow_utime == (unsigned short)-1)
>> -		opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH);
>> -	if (opts->unicode_xlate)
>> -		opts->utf8 = 0;
>> -	if (opts->nfs == FAT_NFS_NOSTALE_RO) {
>> -		sb->s_flags |= SB_RDONLY;
>> -		sb->s_export_op = &fat_export_ops_nostale;
>> +	if (opt < 0)
>> +		return opt;
>> +
>> +	switch (opt) {
>> +	case Opt_check:
>> +		opts->name_check = result.uint_32;
>> +		break;
>> +	case Opt_usefree:
>> +		opts->usefree = 1;
>> +		break;
>> +	case Opt_nocase:
>> +		if (!is_vfat)
>> +			opts->nocase = 1;
>> +		else {
>> +			/* for backward compatibility */
>> +			opts->shortname = VFAT_SFN_DISPLAY_WIN95
>> +				| VFAT_SFN_CREATE_WIN95;
>> +		}
>> +		break;
>> +	case Opt_quiet:
>> +		opts->quiet = 1;
>> +		break;
>> +	case Opt_showexec:
>> +		opts->showexec = 1;
>> +		break;
>> +	case Opt_debug:
>> +		opts->debug = 1;
>> +		break;
>> +	case Opt_immutable:
>> +		opts->sys_immutable = 1;
>> +		break;
>> +	case Opt_uid:
>> +		uid = make_kuid(current_user_ns(), result.uint_32);
>> +		if (!uid_valid(uid))
>> +			return -EINVAL;
>> +		opts->fs_uid = uid;
>> +		break;
>> +	case Opt_gid:
>> +		gid = make_kgid(current_user_ns(), result.uint_32);
>> +		if (!gid_valid(gid))
>> +			return -EINVAL;
>> +		opts->fs_gid = gid;
>> +		break;
>> +	case Opt_umask:
>> +		opts->fs_fmask = opts->fs_dmask = result.uint_32;
>> +		break;
>> +	case Opt_dmask:
>> +		opts->fs_dmask = result.uint_32;
>> +		break;
>> +	case Opt_fmask:
>> +		opts->fs_fmask = result.uint_32;
>> +		break;
>> +	case Opt_allow_utime:
>> +		opts->allow_utime = result.uint_32 & (S_IWGRP | S_IWOTH);
>> +		break;
>> +	case Opt_codepage:
>> +		opts->codepage = result.uint_32;
>> +		break;
>> +	case Opt_flush:
>> +		opts->flush = 1;
>> +		break;
>> +	case Opt_time_offset:
>> +		/*
>> +		 * GMT+-12 zones may have DST corrections so at least
>> +		 * 13 hours difference is needed. Make the limit 24
>> +		 * just in case someone invents something unusual.
>> +		 */
>> +		if (result.int_32 < -24 * 60 || result.int_32 > 24 * 60)
>> +			return -EINVAL;
>> +		opts->tz_set = 1;
>> +		opts->time_offset = result.int_32;
>> +		break;
>> +	case Opt_tz:
>> +		opts->tz_set = 1;
>> +		opts->time_offset = result.uint_32;
>> +		break;
>> +	case Opt_errors:
>> +		opts->errors = result.uint_32;
>> +		break;
>> +	case Opt_nfs:
>> +		opts->nfs = FAT_NFS_STALE_RW;
>> +		break;
>> +	case Opt_nfs_enum:
>> +		opts->nfs = result.uint_32;
>> +		break;
>> +	case Opt_dos1xfloppy:
>> +		opts->dos1xfloppy = 1;
>> +		break;
>> +
>> +	/* msdos specific */
>> +	case Opt_dots:	/* dots / nodots */
>> +		opts->dotsOK = !result.negated;
>> +		break;
>> +	case Opt_dotsOK:	/* dotsOK = yes/no */
>> +		opts->dotsOK = result.boolean;
>> +		break;
>> +
>> +	/* vfat specific */
>> +	case Opt_charset:
>> +		fat_reset_iocharset(opts);
>> +		opts->iocharset = param->string;
>> +		param->string = NULL;	/* Steal string */
>> +		break;
>> +	case Opt_shortname:
>> +		opts->shortname = result.uint_32;
>> +		break;
>> +	case Opt_utf8:
>> +		opts->utf8 = 1;
>> +		break;
>> +	case Opt_utf8_bool:
>> +		opts->utf8 = result.boolean;
>> +		break;
>> +	case Opt_uni_xl:
>> +		opts->unicode_xlate = 1;
>> +		break;
>> +	case Opt_uni_xl_bool:
>> +		opts->unicode_xlate = result.boolean;
>> +		break;
>> +	case Opt_nonumtail:
>> +		opts->numtail = 0;	/* negated option */
>> +		break;
>> +	case Opt_nonumtail_bool:
>> +		opts->numtail = !result.boolean; /* negated option */
>> +		break;
>> +	case Opt_rodir:
>> +		opts->rodir = 1;
>> +		break;
>> +	case Opt_discard:
>> +		opts->discard = 1;
>> +		break;
>> +
>> +	/* obsolete mount options */
>> +	case Opt_obsolete:
>> +		printk(KERN_INFO "FAT-fs: \"%s\" option is obsolete, "
>> +			"not supported now", param->key);
>> +		break;
>> +	default:
>> +		return -EINVAL;
>>  	}
>>  
>>  	return 0;
>>  }
>> +EXPORT_SYMBOL_GPL(fat_parse_param);
>>  
>>  static int fat_read_root(struct inode *inode)
>>  {
>> @@ -1604,9 +1538,11 @@ static int fat_read_static_bpb(struct super_block *sb,
>>  /*
>>   * Read the super block of an MS-DOS FS.
>>   */
>> -int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
>> +int fat_fill_super(struct super_block *sb, struct fs_context *fc,
>>  		   void (*setup)(struct super_block *))
>>  {
>> +	struct fat_mount_options *opts = fc->fs_private;
>> +	int silent = fc->sb_flags & SB_SILENT;
>>  	struct inode *root_inode = NULL, *fat_inode = NULL;
>>  	struct inode *fsinfo_inode = NULL;
>>  	struct buffer_head *bh;
>> @@ -1642,9 +1578,27 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
>>  	ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
>>  			     DEFAULT_RATELIMIT_BURST);
>>  
>> -	error = parse_options(sb, data, isvfat, silent, &sbi->options);
>> -	if (error)
>> -		goto out_fail;
>> +	/* UTF-8 doesn't provide FAT semantics */
>> +	if (!strcmp(opts->iocharset, "utf8")) {
>> +		fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset"
>> +		       " for FAT filesystems, filesystem will be"
>> +		       " case sensitive!");
>> +	}
>> +
>> +	/* If user doesn't specify allow_utime, it's initialized from dmask. */
>> +	if (opts->allow_utime == (unsigned short)-1)
>> +		opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH);
>> +	if (opts->unicode_xlate)
>> +		opts->utf8 = 0;
>> +	if (opts->nfs == FAT_NFS_NOSTALE_RO) {
>> +		sb->s_flags |= SB_RDONLY;
>> +		sb->s_export_op = &fat_export_ops_nostale;
>> +	}
>> +
>> +	/* Apply parsed options to sbi (structure copy) */
>> +	sbi->options = *opts;
>> +	/* Transfer ownership of iocharset to sbi->options */
>> +	opts->iocharset = NULL;
>>  
>>  	setup(sb); /* flavour-specific stuff that needs options */
>>  
>> @@ -1949,6 +1903,57 @@ int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
>>  }
>>  EXPORT_SYMBOL_GPL(fat_flush_inodes);
>>  
>> +int fat_init_fs_context(struct fs_context *fc, bool is_vfat)
>> +{
>> +	struct fat_mount_options *opts;
>> +
>> +	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
>> +	if (!opts)
>> +		return -ENOMEM;
>> +
>> +	opts->isvfat = is_vfat;
>> +	opts->fs_uid = current_uid();
>> +	opts->fs_gid = current_gid();
>> +	opts->fs_fmask = opts->fs_dmask = current_umask();
>> +	opts->allow_utime = -1;
>> +	opts->codepage = fat_default_codepage;
>> +	fat_reset_iocharset(opts);
>> +	if (is_vfat) {
>> +		opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95;
>> +		opts->rodir = 0;
>> +	} else {
>> +		opts->shortname = 0;
>> +		opts->rodir = 1;
>> +	}
>> +	opts->name_check = 'n';
>> +	opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK =  0;
>> +	opts->unicode_xlate = 0;
>> +	opts->numtail = 1;
>> +	opts->usefree = opts->nocase = 0;
>> +	opts->tz_set = 0;
>> +	opts->nfs = 0;
>> +	opts->errors = FAT_ERRORS_RO;
>> +	opts->debug = 0;
>> +
>> +	opts->utf8 = IS_ENABLED(CONFIG_FAT_DEFAULT_UTF8) && is_vfat;
>> +
>> +	fc->fs_private = opts;
>> +	/* fc->ops assigned by caller */
>> +
>> +	return 0;
>> +}
>> +EXPORT_SYMBOL_GPL(fat_init_fs_context);
>> +
>> +void fat_free_fc(struct fs_context *fc)
>> +{
>> +	struct fat_mount_options *opts = fc->fs_private;
>> +
>> +	if (opts->iocharset != fat_default_iocharset)
>> +		kfree(opts->iocharset);
>> +	kfree(fc->fs_private);
>> +}
>> +EXPORT_SYMBOL_GPL(fat_free_fc);
>> +
>>  static int __init init_fat_fs(void)
>>  {
>>  	int err;
>> diff --git a/fs/fat/namei_msdos.c b/fs/fat/namei_msdos.c
>> index 2116c486843b..f06f6ba643cc 100644
>> --- a/fs/fat/namei_msdos.c
>> +++ b/fs/fat/namei_msdos.c
>> @@ -650,24 +650,48 @@ static void setup(struct super_block *sb)
>>  	sb->s_flags |= SB_NOATIME;
>>  }
>>  
>> -static int msdos_fill_super(struct super_block *sb, void *data, int silent)
>> +static int msdos_fill_super(struct super_block *sb, struct fs_context *fc)
>>  {
>> -	return fat_fill_super(sb, data, silent, 0, setup);
>> +	return fat_fill_super(sb, fc, setup);
>>  }
>>  
>> -static struct dentry *msdos_mount(struct file_system_type *fs_type,
>> -			int flags, const char *dev_name,
>> -			void *data)
>> +static int msdos_get_tree(struct fs_context *fc)
>>  {
>> -	return mount_bdev(fs_type, flags, dev_name, data, msdos_fill_super);
>> +	return get_tree_bdev(fc, msdos_fill_super);
>> +}
>> +
>> +static int msdos_parse_param(struct fs_context *fc, struct fs_parameter *param)
>> +{
>> +	return fat_parse_param(fc, param, false);
>> +}
>> +
>> +static const struct fs_context_operations msdos_context_ops = {
>> +	.parse_param	= msdos_parse_param,
>> +	.get_tree	= msdos_get_tree,
>> +	.reconfigure	= fat_reconfigure,
>> +	.free		= fat_free_fc,
>> +};
>> +
>> +static int msdos_init_fs_context(struct fs_context *fc)
>> +{
>> +	int err;
>> +
>> +	/* Initialize with is_vfat == false */
>> +	err = fat_init_fs_context(fc, false);
>> +	if (err)
>> +		return err;
>> +
>> +	fc->ops = &msdos_context_ops;
>> +	return 0;
>>  }
>>  
>>  static struct file_system_type msdos_fs_type = {
>>  	.owner		= THIS_MODULE,
>>  	.name		= "msdos",
>> -	.mount		= msdos_mount,
>>  	.kill_sb	= kill_block_super,
>>  	.fs_flags	= FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
>> +	.init_fs_context = msdos_init_fs_context,
>> +	.parameters	= fat_param_spec,
>>  };
>>  MODULE_ALIAS_FS("msdos");
>>  
>> diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c
>> index c4d00999a433..6423e1dedf14 100644
>> --- a/fs/fat/namei_vfat.c
>> +++ b/fs/fat/namei_vfat.c
>> @@ -1195,24 +1195,48 @@ static void setup(struct super_block *sb)
>>  		sb->s_d_op = &vfat_dentry_ops;
>>  }
>>  
>> -static int vfat_fill_super(struct super_block *sb, void *data, int silent)
>> +static int vfat_fill_super(struct super_block *sb, struct fs_context *fc)
>>  {
>> -	return fat_fill_super(sb, data, silent, 1, setup);
>> +	return fat_fill_super(sb, fc, setup);
>>  }
>>  
>> -static struct dentry *vfat_mount(struct file_system_type *fs_type,
>> -		       int flags, const char *dev_name,
>> -		       void *data)
>> +static int vfat_get_tree(struct fs_context *fc)
>>  {
>> -	return mount_bdev(fs_type, flags, dev_name, data, vfat_fill_super);
>> +	return get_tree_bdev(fc, vfat_fill_super);
>> +}
>> +
>> +static int vfat_parse_param(struct fs_context *fc, struct fs_parameter *param)
>> +{
>> +	return fat_parse_param(fc, param, true);
>> +}
>> +
>> +static const struct fs_context_operations vfat_context_ops = {
>> +	.parse_param	= vfat_parse_param,
>> +	.get_tree	= vfat_get_tree,
>> +	.reconfigure	= fat_reconfigure,
>> +	.free		= fat_free_fc,
>> +};
>> +
>> +static int vfat_init_fs_context(struct fs_context *fc)
>> +{
>> +	int err;
>> +
>> +	/* Initialize with is_vfat == true */
>> +	err = fat_init_fs_context(fc, true);
>> +	if (err)
>> +		return err;
>> +
>> +	fc->ops = &vfat_context_ops;
>> +	return 0;
>>  }
>>  
>>  static struct file_system_type vfat_fs_type = {
>>  	.owner		= THIS_MODULE,
>>  	.name		= "vfat",
>> -	.mount		= vfat_mount,
>>  	.kill_sb	= kill_block_super,
>>  	.fs_flags	= FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
>> +	.init_fs_context = vfat_init_fs_context,
>> +	.parameters     = fat_param_spec,
>>  };
>>  MODULE_ALIAS_FS("vfat");

-- 
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>