[PATCH V2 0/3] fat: convert to the new mount API

All of lore.kernel.org
 help / color / mirror / Atom feed

* [PATCH V2 0/3] fat: convert to the new mount API
@ 2024-07-02 22:39 Eric Sandeen
  2024-07-02 22:41 ` [PATCH V2 1/3] fat: move debug into fat_mount_options Eric Sandeen
                   ` (3 more replies)
  0 siblings, 4 replies; 9+ messages in thread
From: Eric Sandeen @ 2024-07-02 22:39 UTC (permalink / raw)
  To: linux-fsdevel; +Cc: Christian Brauner, OGAWA Hirofumi

This short series converts the fat/vfat/msdos filesystem to use the
new mount API.

V2 addresses the issues raised with the 2nd patch in the first series,
details are in patch this time.

I've tested it with a hacky shell script found at 

https://gist.github.com/sandeen/3492a39c3f2bf16d1ccdd2cd1c681ccd

which tries every possible option, including some with invalid values,
on both vfat and msdos mounts. It then tests random combinations of
2, 3, and 4 options, including possibly invalid options.

I captured stdout from two runs with and without these modifications,
and the results are identical.

As patch 2 notes, I left codepage loading to fill_super(), rather than
validating codepage options as they are parsed. This is because i.e.

mount -o "iocharset=nope,iocharset=iso8859-1"

passes today, due to the last iocharset option being the only one that is
loaded. It might be nice to validate such options as they are parsed, but
doing so would make the above command line fail, so I'm not sure if it's
a good idea. I do have a patch to validate as we parse, if that's desired.

Lastly, the 3rd patch converts to use the new uid/gid helpers as proposed
at https://lore.kernel.org/linux-fsdevel/8dca3c11-99f4-446d-a291-35c50ed2dc14@redhat.com/T/#t
but feel free to squash patches 2 and 3 if you prefer.

Thanks,
-Eric

^ permalink raw reply	[flat|nested] 9+ messages in thread

* [PATCH V2 1/3] fat: move debug into fat_mount_options
  2024-07-02 22:39 [PATCH V2 0/3] fat: convert to the new mount API Eric Sandeen
@ 2024-07-02 22:41 ` Eric Sandeen
  2024-07-03  5:19   ` OGAWA Hirofumi
  2024-07-02 22:44 ` [PATCH V2 2/3] fat: Convert to new mount api Eric Sandeen
                   ` (2 subsequent siblings)
  3 siblings, 1 reply; 9+ messages in thread
From: Eric Sandeen @ 2024-07-02 22:41 UTC (permalink / raw)
  To: linux-fsdevel; +Cc: Christian Brauner, OGAWA Hirofumi

Move the debug variable into fat_mount_options for consistency and
to facilitate conversion to new mount API.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
---
 fs/fat/fat.h   | 3 ++-
 fs/fat/inode.c | 9 ++++-----
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/fs/fat/fat.h b/fs/fat/fat.h
index 66cf4778cf3b..37ced7bb06d5 100644
--- a/fs/fat/fat.h
+++ b/fs/fat/fat.h
@@ -51,7 +51,8 @@ struct fat_mount_options {
 		 tz_set:1,	   /* Filesystem timestamps' offset set */
 		 rodir:1,	   /* allow ATTR_RO for directory */
 		 discard:1,	   /* Issue discard requests on deletions */
-		 dos1xfloppy:1;	   /* Assume default BPB for DOS 1.x floppies */
+		 dos1xfloppy:1,	   /* Assume default BPB for DOS 1.x floppies */
+		 debug:1;	   /* Not currently used */
 };
 
 #define FAT_HASH_BITS	8
diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index d9e6fbb6f246..2a6537ba0d49 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -1132,7 +1132,7 @@ static const match_table_t vfat_tokens = {
 };
 
 static int parse_options(struct super_block *sb, char *options, int is_vfat,
-			 int silent, int *debug, struct fat_mount_options *opts)
+			 int silent, struct fat_mount_options *opts)
 {
 	char *p;
 	substring_t args[MAX_OPT_ARGS];
@@ -1162,7 +1162,7 @@ static int parse_options(struct super_block *sb, char *options, int is_vfat,
 	opts->tz_set = 0;
 	opts->nfs = 0;
 	opts->errors = FAT_ERRORS_RO;
-	*debug = 0;
+	opts->debug = 0;
 
 	opts->utf8 = IS_ENABLED(CONFIG_FAT_DEFAULT_UTF8) && is_vfat;
 
@@ -1210,7 +1210,7 @@ static int parse_options(struct super_block *sb, char *options, int is_vfat,
 			opts->showexec = 1;
 			break;
 		case Opt_debug:
-			*debug = 1;
+			opts->debug = 1;
 			break;
 		case Opt_immutable:
 			opts->sys_immutable = 1;
@@ -1614,7 +1614,6 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
 	struct msdos_sb_info *sbi;
 	u16 logical_sector_size;
 	u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
-	int debug;
 	long error;
 	char buf[50];
 	struct timespec64 ts;
@@ -1643,7 +1642,7 @@ 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, &debug, &sbi->options);
+	error = parse_options(sb, data, isvfat, silent, &sbi->options);
 	if (error)
 		goto out_fail;
 
-- 
2.45.2



^ permalink raw reply related	[flat|nested] 9+ messages in thread

* Re: [PATCH V2 1/3] fat: move debug into fat_mount_options
  2024-07-02 22:41 ` [PATCH V2 1/3] fat: move debug into fat_mount_options Eric Sandeen
@ 2024-07-03  5:19   ` OGAWA Hirofumi
  0 siblings, 0 replies; 9+ messages in thread
From: OGAWA Hirofumi @ 2024-07-03  5:19 UTC (permalink / raw)
  To: Eric Sandeen; +Cc: Andrew Morton, linux-fsdevel, Christian Brauner

Eric Sandeen <sandeen@redhat.com> writes:

> Move the debug variable into fat_mount_options for consistency and
> to facilitate conversion to new mount API.
>
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>

Looks good. (maybe, this patchset should go with your patch series with
fsparam_uid/gid?)

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

Thanks.

> ---
>  fs/fat/fat.h   | 3 ++-
>  fs/fat/inode.c | 9 ++++-----
>  2 files changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/fs/fat/fat.h b/fs/fat/fat.h
> index 66cf4778cf3b..37ced7bb06d5 100644
> --- a/fs/fat/fat.h
> +++ b/fs/fat/fat.h
> @@ -51,7 +51,8 @@ struct fat_mount_options {
>  		 tz_set:1,	   /* Filesystem timestamps' offset set */
>  		 rodir:1,	   /* allow ATTR_RO for directory */
>  		 discard:1,	   /* Issue discard requests on deletions */
> -		 dos1xfloppy:1;	   /* Assume default BPB for DOS 1.x floppies */
> +		 dos1xfloppy:1,	   /* Assume default BPB for DOS 1.x floppies */
> +		 debug:1;	   /* Not currently used */
>  };
>  
>  #define FAT_HASH_BITS	8
> diff --git a/fs/fat/inode.c b/fs/fat/inode.c
> index d9e6fbb6f246..2a6537ba0d49 100644
> --- a/fs/fat/inode.c
> +++ b/fs/fat/inode.c
> @@ -1132,7 +1132,7 @@ static const match_table_t vfat_tokens = {
>  };
>  
>  static int parse_options(struct super_block *sb, char *options, int is_vfat,
> -			 int silent, int *debug, struct fat_mount_options *opts)
> +			 int silent, struct fat_mount_options *opts)
>  {
>  	char *p;
>  	substring_t args[MAX_OPT_ARGS];
> @@ -1162,7 +1162,7 @@ static int parse_options(struct super_block *sb, char *options, int is_vfat,
>  	opts->tz_set = 0;
>  	opts->nfs = 0;
>  	opts->errors = FAT_ERRORS_RO;
> -	*debug = 0;
> +	opts->debug = 0;
>  
>  	opts->utf8 = IS_ENABLED(CONFIG_FAT_DEFAULT_UTF8) && is_vfat;
>  
> @@ -1210,7 +1210,7 @@ static int parse_options(struct super_block *sb, char *options, int is_vfat,
>  			opts->showexec = 1;
>  			break;
>  		case Opt_debug:
> -			*debug = 1;
> +			opts->debug = 1;
>  			break;
>  		case Opt_immutable:
>  			opts->sys_immutable = 1;
> @@ -1614,7 +1614,6 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
>  	struct msdos_sb_info *sbi;
>  	u16 logical_sector_size;
>  	u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
> -	int debug;
>  	long error;
>  	char buf[50];
>  	struct timespec64 ts;
> @@ -1643,7 +1642,7 @@ 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, &debug, &sbi->options);
> +	error = parse_options(sb, data, isvfat, silent, &sbi->options);
>  	if (error)
>  		goto out_fail;

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

^ permalink raw reply	[flat|nested] 9+ messages in thread

* [PATCH V2 2/3] fat: Convert to new mount api
  2024-07-02 22:39 [PATCH V2 0/3] fat: convert to the new mount API Eric Sandeen
  2024-07-02 22:41 ` [PATCH V2 1/3] fat: move debug into fat_mount_options Eric Sandeen
@ 2024-07-02 22:44 ` Eric Sandeen
  2024-07-03  5:19   ` OGAWA Hirofumi
  2024-07-02 22:45 ` [PATCH V2 3/3] fat: Convert to new uid/gid option parsing helpers Eric Sandeen
  2024-07-03  8:49 ` [PATCH V2 0/3] fat: convert to the new mount API Christian Brauner
  3 siblings, 1 reply; 9+ messages in thread
From: Eric Sandeen @ 2024-07-02 22:44 UTC (permalink / raw)
  To: linux-fsdevel; +Cc: Christian Brauner, OGAWA Hirofumi

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>
---

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");
 
-- 
2.45.2



^ permalink raw reply related	[flat|nested] 9+ messages in thread

* Re: [PATCH V2 2/3] fat: Convert to new mount api
  2024-07-02 22:44 ` [PATCH V2 2/3] fat: Convert to new mount api Eric Sandeen
@ 2024-07-03  5:19   ` OGAWA Hirofumi
  2024-07-03  5:21     ` OGAWA Hirofumi
  0 siblings, 1 reply; 9+ messages in thread
From: OGAWA Hirofumi @ 2024-07-03  5:19 UTC (permalink / raw)
  To: Eric Sandeen; +Cc: linux-fsdevel, Christian Brauner

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>

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH V2 2/3] fat: Convert to new mount api
  2024-07-03  5:19   ` OGAWA Hirofumi
@ 2024-07-03  5:21     ` OGAWA Hirofumi
  0 siblings, 0 replies; 9+ messages in thread
From: OGAWA Hirofumi @ 2024-07-03  5:21 UTC (permalink / raw)
  To: Eric Sandeen; +Cc: Andrew Morton, linux-fsdevel, Christian Brauner

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>

^ permalink raw reply	[flat|nested] 9+ messages in thread

* [PATCH V2 3/3] fat: Convert to new uid/gid option parsing helpers
  2024-07-02 22:39 [PATCH V2 0/3] fat: convert to the new mount API Eric Sandeen
  2024-07-02 22:41 ` [PATCH V2 1/3] fat: move debug into fat_mount_options Eric Sandeen
  2024-07-02 22:44 ` [PATCH V2 2/3] fat: Convert to new mount api Eric Sandeen
@ 2024-07-02 22:45 ` Eric Sandeen
  2024-07-03  5:20   ` OGAWA Hirofumi
  2024-07-03  8:49 ` [PATCH V2 0/3] fat: convert to the new mount API Christian Brauner
  3 siblings, 1 reply; 9+ messages in thread
From: Eric Sandeen @ 2024-07-02 22:45 UTC (permalink / raw)
  To: linux-fsdevel; +Cc: Christian Brauner, OGAWA Hirofumi

Convert to new uid/gid option parsing helpers

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
---
 fs/fat/inode.c | 16 ++++------------
 1 file changed, 4 insertions(+), 12 deletions(-)

diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index b83b39f2f69b..8fbf5edb7aa2 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -1091,8 +1091,8 @@ static const struct constant_table fat_param_conv[] = {
 /* 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_uid	("uid",		Opt_uid),
+	fsparam_gid	("gid",		Opt_gid),
 	fsparam_u32oct	("umask",	Opt_umask),
 	fsparam_u32oct	("dmask",	Opt_dmask),
 	fsparam_u32oct	("fmask",	Opt_fmask),
@@ -1161,8 +1161,6 @@ int fat_parse_param(struct fs_context *fc, struct fs_parameter *param,
 	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)
@@ -1209,16 +1207,10 @@ int fat_parse_param(struct fs_context *fc, struct fs_parameter *param,
 		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;
+		opts->fs_uid = result.uid;
 		break;
 	case Opt_gid:
-		gid = make_kgid(current_user_ns(), result.uint_32);
-		if (!gid_valid(gid))
-			return -EINVAL;
-		opts->fs_gid = gid;
+		opts->fs_gid = result.gid;
 		break;
 	case Opt_umask:
 		opts->fs_fmask = opts->fs_dmask = result.uint_32;
-- 
2.45.2



^ permalink raw reply related	[flat|nested] 9+ messages in thread

* Re: [PATCH V2 3/3] fat: Convert to new uid/gid option parsing helpers
  2024-07-02 22:45 ` [PATCH V2 3/3] fat: Convert to new uid/gid option parsing helpers Eric Sandeen
@ 2024-07-03  5:20   ` OGAWA Hirofumi
  0 siblings, 0 replies; 9+ messages in thread
From: OGAWA Hirofumi @ 2024-07-03  5:20 UTC (permalink / raw)
  To: Eric Sandeen; +Cc: Andrew Morton, linux-fsdevel, Christian Brauner

Eric Sandeen <sandeen@redhat.com> writes:

> Convert to new uid/gid option parsing helpers
>
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>

Looks good.

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

Thanks.

> ---
>  fs/fat/inode.c | 16 ++++------------
>  1 file changed, 4 insertions(+), 12 deletions(-)
>
> diff --git a/fs/fat/inode.c b/fs/fat/inode.c
> index b83b39f2f69b..8fbf5edb7aa2 100644
> --- a/fs/fat/inode.c
> +++ b/fs/fat/inode.c
> @@ -1091,8 +1091,8 @@ static const struct constant_table fat_param_conv[] = {
>  /* 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_uid	("uid",		Opt_uid),
> +	fsparam_gid	("gid",		Opt_gid),
>  	fsparam_u32oct	("umask",	Opt_umask),
>  	fsparam_u32oct	("dmask",	Opt_dmask),
>  	fsparam_u32oct	("fmask",	Opt_fmask),
> @@ -1161,8 +1161,6 @@ int fat_parse_param(struct fs_context *fc, struct fs_parameter *param,
>  	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)
> @@ -1209,16 +1207,10 @@ int fat_parse_param(struct fs_context *fc, struct fs_parameter *param,
>  		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;
> +		opts->fs_uid = result.uid;
>  		break;
>  	case Opt_gid:
> -		gid = make_kgid(current_user_ns(), result.uint_32);
> -		if (!gid_valid(gid))
> -			return -EINVAL;
> -		opts->fs_gid = gid;
> +		opts->fs_gid = result.gid;
>  		break;
>  	case Opt_umask:
>  		opts->fs_fmask = opts->fs_dmask = result.uint_32;

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

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH V2 0/3] fat: convert to the new mount API
  2024-07-02 22:39 [PATCH V2 0/3] fat: convert to the new mount API Eric Sandeen
                   ` (2 preceding siblings ...)
  2024-07-02 22:45 ` [PATCH V2 3/3] fat: Convert to new uid/gid option parsing helpers Eric Sandeen
@ 2024-07-03  8:49 ` Christian Brauner
  3 siblings, 0 replies; 9+ messages in thread
From: Christian Brauner @ 2024-07-03  8:49 UTC (permalink / raw)
  To: linux-fsdevel, Eric Sandeen; +Cc: Christian Brauner, OGAWA Hirofumi

On Tue, 02 Jul 2024 17:39:25 -0500, Eric Sandeen wrote:
> This short series converts the fat/vfat/msdos filesystem to use the
> new mount API.
> 
> V2 addresses the issues raised with the 2nd patch in the first series,
> details are in patch this time.
> 
> I've tested it with a hacky shell script found at
> 
> [...]

Applied to the vfs.mount.api branch of the vfs/vfs.git tree.
Patches in the vfs.mount.api branch should appear in linux-next soon.

Please report any outstanding bugs that were missed during review in a
new review to the original patch series allowing us to drop it.

It's encouraged to provide Acked-bys and Reviewed-bys even though the
patch has now been applied. If possible patch trailers will be updated.

Note that commit hashes shown below are subject to change due to rebase,
trailer updates or similar. If in doubt, please check the listed branch.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git
branch: vfs.mount.api

[1/3] fat: move debug into fat_mount_options
      https://git.kernel.org/vfs/vfs/c/206d3d8e006c
[2/3] fat: Convert to new mount api
      https://git.kernel.org/vfs/vfs/c/634440b69c7f
[3/3] fat: Convert to new uid/gid option parsing helpers
      https://git.kernel.org/vfs/vfs/c/d02f0bb332d5

^ permalink raw reply	[flat|nested] 9+ messages in thread

end of thread, other threads:[~2024-07-03  8:49 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2024-07-02 22:39 [PATCH V2 0/3] fat: convert to the new mount API Eric Sandeen
2024-07-02 22:41 ` [PATCH V2 1/3] fat: move debug into fat_mount_options Eric Sandeen
2024-07-03  5:19   ` OGAWA Hirofumi
2024-07-02 22:44 ` [PATCH V2 2/3] fat: Convert to new mount api Eric Sandeen
2024-07-03  5:19   ` OGAWA Hirofumi
2024-07-03  5:21     ` OGAWA Hirofumi
2024-07-02 22:45 ` [PATCH V2 3/3] fat: Convert to new uid/gid option parsing helpers Eric Sandeen
2024-07-03  5:20   ` OGAWA Hirofumi
2024-07-03  8:49 ` [PATCH V2 0/3] fat: convert to the new mount API Christian Brauner

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.