Merge tag 'vfs-6.11.mount.api' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull vfs mount API updates from Christian Brauner:

 - Add a generic helper to parse uid and gid mount options.

   Currently we open-code the same logic in various filesystems which is
   error prone, especially since the verification of uid and gid mount
   options is a sensitive operation in the face of idmappings.

   Add a generic helper and convert all filesystems over to it. Make
   sure that filesystems that are mountable in unprivileged containers
   verify that the specified uid and gid can be represented in the
   owning namespace of the filesystem.

 - Convert hostfs to the new mount api.

* tag 'vfs-6.11.mount.api' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  fuse: Convert to new uid/gid option parsing helpers
  fuse: verify {g,u}id mount options correctly
  fat: Convert to new uid/gid option parsing helpers
  fat: Convert to new mount api
  fat: move debug into fat_mount_options
  vboxsf: Convert to new uid/gid option parsing helpers
  tracefs: Convert to new uid/gid option parsing helpers
  smb: client: Convert to new uid/gid option parsing helpers
  tmpfs: Convert to new uid/gid option parsing helpers
  ntfs3: Convert to new uid/gid option parsing helpers
  isofs: Convert to new uid/gid option parsing helpers
  hugetlbfs: Convert to new uid/gid option parsing helpers
  ext4: Convert to new uid/gid option parsing helpers
  exfat: Convert to new uid/gid option parsing helpers
  efivarfs: Convert to new uid/gid option parsing helpers
  debugfs: Convert to new uid/gid option parsing helpers
  autofs: Convert to new uid/gid option parsing helpers
  fs_parse: add uid & gid option option parsing helpers
  hostfs: Add const qualifier to host_root in hostfs_fill_super()
  hostfs: convert hostfs to use the new mount API

Author: torvalds

Documentation/filesystems/mount_api.rst

@@ -645,6 +645,8 @@ The members are as follows:
 	fs_param_is_blockdev	Blockdev path		* Needs lookup
 	fs_param_is_path	Path			* Needs lookup
 	fs_param_is_fd		File descriptor		result->int_32
+	fs_param_is_uid		User ID (u32)           result->uid
+	fs_param_is_gid		Group ID (u32)          result->gid
 	=======================	=======================	=====================
 
      Note that if the value is of fs_param_is_bool type, fs_parse() will try
@@ -678,6 +680,8 @@ The members are as follows:
 	fsparam_bdev()		fs_param_is_blockdev
 	fsparam_path()		fs_param_is_path
 	fsparam_fd()		fs_param_is_fd
+	fsparam_uid()		fs_param_is_uid
+	fsparam_gid()		fs_param_is_gid
 	=======================	===============================================
 
      all of which take two arguments, name string and option number - for
@@ -784,8 +788,9 @@ process the parameters it is given.
      option number (which it returns).
 
      If successful, and if the parameter type indicates the result is a
-     boolean, integer or enum type, the value is converted by this function and
-     the result stored in result->{boolean,int_32,uint_32,uint_64}.
+     boolean, integer, enum, uid, or gid type, the value is converted by this
+     function and the result stored in
+     result->{boolean,int_32,uint_32,uint_64,uid,gid}.
 
      If a match isn't initially made, the key is prefixed with "no" and no
      value is present then an attempt will be made to look up the key with the

fs/autofs/inode.c

@@ -126,15 +126,15 @@ enum {
 const struct fs_parameter_spec autofs_param_specs[] = {
 	fsparam_flag	("direct",		Opt_direct),
 	fsparam_fd	("fd",			Opt_fd),
-	fsparam_u32	("gid",			Opt_gid),
+	fsparam_gid	("gid",			Opt_gid),
 	fsparam_flag	("ignore",		Opt_ignore),
 	fsparam_flag	("indirect",		Opt_indirect),
 	fsparam_u32	("maxproto",		Opt_maxproto),
 	fsparam_u32	("minproto",		Opt_minproto),
 	fsparam_flag	("offset",		Opt_offset),
 	fsparam_u32	("pgrp",		Opt_pgrp),
 	fsparam_flag	("strictexpire",	Opt_strictexpire),
-	fsparam_u32	("uid",			Opt_uid),
+	fsparam_uid	("uid",			Opt_uid),
 	{}
 };
 
@@ -193,8 +193,6 @@ static int autofs_parse_param(struct fs_context *fc, struct fs_parameter *param)
 	struct autofs_fs_context *ctx = fc->fs_private;
 	struct autofs_sb_info *sbi = fc->s_fs_info;
 	struct fs_parse_result result;
-	kuid_t uid;
-	kgid_t gid;
 	int opt;
 
 	opt = fs_parse(fc, autofs_param_specs, param, &result);
@@ -205,16 +203,10 @@ static int autofs_parse_param(struct fs_context *fc, struct fs_parameter *param)
 	case Opt_fd:
 		return autofs_parse_fd(fc, sbi, param, &result);
 	case Opt_uid:
-		uid = make_kuid(current_user_ns(), result.uint_32);
-		if (!uid_valid(uid))
-			return invalfc(fc, "Invalid uid");
-		ctx->uid = uid;
+		ctx->uid = result.uid;
 		break;
 	case Opt_gid:
-		gid = make_kgid(current_user_ns(), result.uint_32);
-		if (!gid_valid(gid))
-			return invalfc(fc, "Invalid gid");
-		ctx->gid = gid;
+		ctx->gid = result.gid;
 		break;
 	case Opt_pgrp:
 		ctx->pgrp = result.uint_32;

fs/debugfs/inode.c

@@ -92,18 +92,16 @@ enum {
 };
 
 static const struct fs_parameter_spec debugfs_param_specs[] = {
-	fsparam_u32	("gid",		Opt_gid),
+	fsparam_gid	("gid",		Opt_gid),
 	fsparam_u32oct	("mode",	Opt_mode),
-	fsparam_u32	("uid",		Opt_uid),
+	fsparam_uid	("uid",		Opt_uid),
 	{}
 };
 
 static int debugfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
 {
 	struct debugfs_fs_info *opts = fc->s_fs_info;
 	struct fs_parse_result result;
-	kuid_t uid;
-	kgid_t gid;
 	int opt;
 
 	opt = fs_parse(fc, debugfs_param_specs, param, &result);
@@ -120,16 +118,10 @@ static int debugfs_parse_param(struct fs_context *fc, struct fs_parameter *param
 
 	switch (opt) {
 	case Opt_uid:
-		uid = make_kuid(current_user_ns(), result.uint_32);
-		if (!uid_valid(uid))
-			return invalf(fc, "Unknown uid");
-		opts->uid = uid;
+		opts->uid = result.uid;
 		break;
 	case Opt_gid:
-		gid = make_kgid(current_user_ns(), result.uint_32);
-		if (!gid_valid(gid))
-			return invalf(fc, "Unknown gid");
-		opts->gid = gid;
+		opts->gid = result.gid;
 		break;
 	case Opt_mode:
 		opts->mode = result.uint_32 & S_IALLUGO;

fs/efivarfs/super.c

@@ -275,8 +275,8 @@ enum {
 };
 
 static const struct fs_parameter_spec efivarfs_parameters[] = {
-	fsparam_u32("uid", Opt_uid),
-	fsparam_u32("gid", Opt_gid),
+	fsparam_uid("uid", Opt_uid),
+	fsparam_gid("gid", Opt_gid),
 	{},
 };
 
@@ -293,14 +293,10 @@ static int efivarfs_parse_param(struct fs_context *fc, struct fs_parameter *para
 
 	switch (opt) {
 	case Opt_uid:
-		opts->uid = make_kuid(current_user_ns(), result.uint_32);
-		if (!uid_valid(opts->uid))
-			return -EINVAL;
+		opts->uid = result.uid;
 		break;
 	case Opt_gid:
-		opts->gid = make_kgid(current_user_ns(), result.uint_32);
-		if (!gid_valid(opts->gid))
-			return -EINVAL;
+		opts->gid = result.gid;
 		break;
 	default:
 		return -EINVAL;

fs/exfat/super.c

@@ -225,8 +225,8 @@ static const struct constant_table exfat_param_enums[] = {
 };
 
 static const struct fs_parameter_spec exfat_parameters[] = {
-	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),
@@ -262,10 +262,10 @@ static int exfat_parse_param(struct fs_context *fc, struct fs_parameter *param)
 
 	switch (opt) {
 	case Opt_uid:
-		opts->fs_uid = make_kuid(current_user_ns(), result.uint_32);
+		opts->fs_uid = result.uid;
 		break;
 	case Opt_gid:
-		opts->fs_gid = make_kgid(current_user_ns(), result.uint_32);
+		opts->fs_gid = result.gid;
 		break;
 	case Opt_umask:
 		opts->fs_fmask = result.uint_32;

fs/ext4/super.c

@@ -1721,8 +1721,8 @@ static const struct fs_parameter_spec ext4_param_specs[] = {
 	fsparam_flag	("bsdgroups",		Opt_grpid),
 	fsparam_flag	("nogrpid",		Opt_nogrpid),
 	fsparam_flag	("sysvgroups",		Opt_nogrpid),
-	fsparam_u32	("resgid",		Opt_resgid),
-	fsparam_u32	("resuid",		Opt_resuid),
+	fsparam_gid	("resgid",		Opt_resgid),
+	fsparam_uid	("resuid",		Opt_resuid),
 	fsparam_u32	("sb",			Opt_sb),
 	fsparam_enum	("errors",		Opt_errors, ext4_param_errors),
 	fsparam_flag	("nouid32",		Opt_nouid32),
@@ -2127,8 +2127,6 @@ static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param)
 	struct fs_parse_result result;
 	const struct mount_opts *m;
 	int is_remount;
-	kuid_t uid;
-	kgid_t gid;
 	int token;
 
 	token = fs_parse(fc, ext4_param_specs, param, &result);
@@ -2270,23 +2268,11 @@ static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param)
 		ctx->spec |= EXT4_SPEC_s_stripe;
 		return 0;
 	case Opt_resuid:
-		uid = make_kuid(current_user_ns(), result.uint_32);
-		if (!uid_valid(uid)) {
-			ext4_msg(NULL, KERN_ERR, "Invalid uid value %d",
-				 result.uint_32);
-			return -EINVAL;
-		}
-		ctx->s_resuid = uid;
+		ctx->s_resuid = result.uid;
 		ctx->spec |= EXT4_SPEC_s_resuid;
 		return 0;
 	case Opt_resgid:
-		gid = make_kgid(current_user_ns(), result.uint_32);
-		if (!gid_valid(gid)) {
-			ext4_msg(NULL, KERN_ERR, "Invalid gid value %d",
-				 result.uint_32);
-			return -EINVAL;
-		}
-		ctx->s_resgid = gid;
+		ctx->s_resgid = result.gid;
 		ctx->spec |= EXT4_SPEC_s_resgid;
 		return 0;
 	case Opt_journal_dev:

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
@@ -51,7 +53,8 @@ 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
@@ -415,12 +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);