Merge patch series "adfs, affs, befs, hfs, hfsplus: convert to new mount api"

Eric Sandeen <sandeen@redhat.com> says:

These were all tested against images I created or obtained, using a
script to test random combinations of valid and invalid mount and
remount options, and comparing the results before and after the changes.

AFAICT, all parsing works as expected and behavior is unchanged.

* patches from https://lore.kernel.org/r/20240916172735.866916-1-sandeen@redhat.com:
  hfsplus: convert hfsplus to use the new mount api
  hfs: convert hfs to use the new mount api
  befs: convert befs to use the new mount api
  affs: convert affs to use the new mount api
  adfs: convert adfs to use the new mount api

Link: https://lore.kernel.org/r/20240916172735.866916-1-sandeen@redhat.com
Signed-off-by: Christian Brauner <brauner@kernel.org>

3 files changed, 149 insertions, 202 deletions

diff --git a/fs/hfsplus/hfsplus_fs.h b/fs/hfsplus/hfsplus_fs.h
index 59ce81dca73f..b733ef0c1547 100644
--- a/fs/hfsplus/hfsplus_fs.h
+++ b/fs/hfsplus/hfsplus_fs.h
@@ -21,6 +21,7 @@
 #include <linux/mutex.h>
 #include <linux/buffer_head.h>
 #include <linux/blkdev.h>
+#include <linux/fs_context.h>
 #include "hfsplus_raw.h"
 
 #define DBG_BNODE_REFS	0x00000001
@@ -496,8 +497,7 @@ long hfsplus_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);
 
 /* options.c */
 void hfsplus_fill_defaults(struct hfsplus_sb_info *opts);
-int hfsplus_parse_options_remount(char *input, int *force);
-int hfsplus_parse_options(char *input, struct hfsplus_sb_info *sbi);
+int hfsplus_parse_param(struct fs_context *fc, struct fs_parameter *param);
 int hfsplus_show_options(struct seq_file *seq, struct dentry *root);
 
 /* part_tbl.c */
diff --git a/fs/hfsplus/options.c b/fs/hfsplus/options.c
index c94a58762ad6..a66a09a56bf7 100644
--- a/fs/hfsplus/options.c
+++ b/fs/hfsplus/options.c
@@ -12,7 +12,8 @@
 #include <linux/string.h>
 #include <linux/kernel.h>
 #include <linux/sched.h>
-#include <linux/parser.h>
+#include <linux/fs_context.h>
+#include <linux/fs_parser.h>
 #include <linux/nls.h>
 #include <linux/mount.h>
 #include <linux/seq_file.h>
@@ -23,26 +24,23 @@ enum {
 	opt_creator, opt_type,
 	opt_umask, opt_uid, opt_gid,
 	opt_part, opt_session, opt_nls,
-	opt_nodecompose, opt_decompose,
-	opt_barrier, opt_nobarrier,
-	opt_force, opt_err
+	opt_decompose, opt_barrier,
+	opt_force,
 };
 
-static const match_table_t tokens = {
-	{ opt_creator, "creator=%s" },
-	{ opt_type, "type=%s" },
-	{ opt_umask, "umask=%o" },
-	{ opt_uid, "uid=%u" },
-	{ opt_gid, "gid=%u" },
-	{ opt_part, "part=%u" },
-	{ opt_session, "session=%u" },
-	{ opt_nls, "nls=%s" },
-	{ opt_decompose, "decompose" },
-	{ opt_nodecompose, "nodecompose" },
-	{ opt_barrier, "barrier" },
-	{ opt_nobarrier, "nobarrier" },
-	{ opt_force, "force" },
-	{ opt_err, NULL }
+static const struct fs_parameter_spec hfs_param_spec[] = {
+	fsparam_string	("creator",	opt_creator),
+	fsparam_string	("type",	opt_type),
+	fsparam_u32oct	("umask",	opt_umask),
+	fsparam_u32	("uid",		opt_uid),
+	fsparam_u32	("gid",		opt_gid),
+	fsparam_u32	("part",	opt_part),
+	fsparam_u32	("session",	opt_session),
+	fsparam_string	("nls",		opt_nls),
+	fsparam_flag_no	("decompose",	opt_decompose),
+	fsparam_flag_no	("barrier",	opt_barrier),
+	fsparam_flag	("force",	opt_force),
+	{}
 };
 
 /* Initialize an options object to reasonable defaults */
@@ -60,162 +58,89 @@ void hfsplus_fill_defaults(struct hfsplus_sb_info *opts)
 	opts->session = -1;
 }
 
-/* convert a "four byte character" to a 32 bit int with error checks */
-static inline int match_fourchar(substring_t *arg, u32 *result)
+/* Parse options from mount. Returns nonzero errno on failure */
+int hfsplus_parse_param(struct fs_context *fc, struct fs_parameter *param)
 {
-	if (arg->to - arg->from != 4)
-		return -EINVAL;
-	memcpy(result, arg->from, 4);
-	return 0;
-}
-
-int hfsplus_parse_options_remount(char *input, int *force)
-{
-	char *p;
-	substring_t args[MAX_OPT_ARGS];
-	int token;
-
-	if (!input)
-		return 1;
-
-	while ((p = strsep(&input, ",")) != NULL) {
-		if (!*p)
-			continue;
-
-		token = match_token(p, tokens, args);
-		switch (token) {
-		case opt_force:
-			*force = 1;
-			break;
-		default:
-			break;
+	struct hfsplus_sb_info *sbi = fc->s_fs_info;
+	struct fs_parse_result result;
+	int opt;
+
+	/*
+	 * Only the force option is examined during remount, all others
+	 * are ignored.
+	 */
+	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE &&
+	    strncmp(param->key, "force", 5))
+		return 0;
+
+	opt = fs_parse(fc, hfs_param_spec, param, &result);
+	if (opt < 0)
+		return opt;
+
+	switch (opt) {
+	case opt_creator:
+		if (strlen(param->string) != 4) {
+			pr_err("creator requires a 4 character value\n");
+			return -EINVAL;
 		}
-	}
-
-	return 1;
-}
-
-/* Parse options from mount. Returns 0 on failure */
-/* input is the options passed to mount() as a string */
-int hfsplus_parse_options(char *input, struct hfsplus_sb_info *sbi)
-{
-	char *p;
-	substring_t args[MAX_OPT_ARGS];
-	int tmp, token;
-
-	if (!input)
-		goto done;
-
-	while ((p = strsep(&input, ",")) != NULL) {
-		if (!*p)
-			continue;
-
-		token = match_token(p, tokens, args);
-		switch (token) {
-		case opt_creator:
-			if (match_fourchar(&args[0], &sbi->creator)) {
-				pr_err("creator requires a 4 character value\n");
-				return 0;
-			}
-			break;
-		case opt_type:
-			if (match_fourchar(&args[0], &sbi->type)) {
-				pr_err("type requires a 4 character value\n");
-				return 0;
-			}
-			break;
-		case opt_umask:
-			if (match_octal(&args[0], &tmp)) {
-				pr_err("umask requires a value\n");
-				return 0;
-			}
-			sbi->umask = (umode_t)tmp;
-			break;
-		case opt_uid:
-			if (match_int(&args[0], &tmp)) {
-				pr_err("uid requires an argument\n");
-				return 0;
-			}
-			sbi->uid = make_kuid(current_user_ns(), (uid_t)tmp);
-			if (!uid_valid(sbi->uid)) {
-				pr_err("invalid uid specified\n");
-				return 0;
-			} else {
-				set_bit(HFSPLUS_SB_UID, &sbi->flags);
-			}
-			break;
-		case opt_gid:
-			if (match_int(&args[0], &tmp)) {
-				pr_err("gid requires an argument\n");
-				return 0;
-			}
-			sbi->gid = make_kgid(current_user_ns(), (gid_t)tmp);
-			if (!gid_valid(sbi->gid)) {
-				pr_err("invalid gid specified\n");
-				return 0;
-			} else {
-				set_bit(HFSPLUS_SB_GID, &sbi->flags);
-			}
-			break;
-		case opt_part:
-			if (match_int(&args[0], &sbi->part)) {
-				pr_err("part requires an argument\n");
-				return 0;
-			}
-			break;
-		case opt_session:
-			if (match_int(&args[0], &sbi->session)) {
-				pr_err("session requires an argument\n");
-				return 0;
-			}
-			break;
-		case opt_nls:
-			if (sbi->nls) {
-				pr_err("unable to change nls mapping\n");
-				return 0;
-			}
-			p = match_strdup(&args[0]);
-			if (p)
-				sbi->nls = load_nls(p);
-			if (!sbi->nls) {
-				pr_err("unable to load nls mapping \"%s\"\n",
-				       p);
-				kfree(p);
-				return 0;
-			}
-			kfree(p);
-			break;
-		case opt_decompose:
-			clear_bit(HFSPLUS_SB_NODECOMPOSE, &sbi->flags);
-			break;
-		case opt_nodecompose:
+		memcpy(&sbi->creator, param->string, 4);
+		break;
+	case opt_type:
+		if (strlen(param->string) != 4) {
+			pr_err("type requires a 4 character value\n");
+			return -EINVAL;
+		}
+		memcpy(&sbi->type, param->string, 4);
+		break;
+	case opt_umask:
+		sbi->umask = (umode_t)result.uint_32;
+		break;
+	case opt_uid:
+		sbi->uid = result.uid;
+		set_bit(HFSPLUS_SB_UID, &sbi->flags);
+		break;
+	case opt_gid:
+		sbi->gid = result.gid;
+		set_bit(HFSPLUS_SB_GID, &sbi->flags);
+		break;
+	case opt_part:
+		sbi->part = result.uint_32;
+		break;
+	case opt_session:
+		sbi->session = result.uint_32;
+		break;
+	case opt_nls:
+		if (sbi->nls) {
+			pr_err("unable to change nls mapping\n");
+			return -EINVAL;
+		}
+		sbi->nls = load_nls(param->string);
+		if (!sbi->nls) {
+			pr_err("unable to load nls mapping \"%s\"\n",
+			       param->string);
+			return -EINVAL;
+		}
+		break;
+	case opt_decompose:
+		if (result.negated)
 			set_bit(HFSPLUS_SB_NODECOMPOSE, &sbi->flags);
-			break;
-		case opt_barrier:
-			clear_bit(HFSPLUS_SB_NOBARRIER, &sbi->flags);
-			break;
-		case opt_nobarrier:
+		else
+			clear_bit(HFSPLUS_SB_NODECOMPOSE, &sbi->flags);
+		break;
+	case opt_barrier:
+		if (result.negated)
 			set_bit(HFSPLUS_SB_NOBARRIER, &sbi->flags);
-			break;
-		case opt_force:
-			set_bit(HFSPLUS_SB_FORCE, &sbi->flags);
-			break;
-		default:
-			return 0;
-		}
-	}
-
-done:
-	if (!sbi->nls) {
-		/* try utf8 first, as this is the old default behaviour */
-		sbi->nls = load_nls("utf8");
-		if (!sbi->nls)
-			sbi->nls = load_nls_default();
-		if (!sbi->nls)
-			return 0;
+		else
+			clear_bit(HFSPLUS_SB_NOBARRIER, &sbi->flags);
+		break;
+	case opt_force:
+		set_bit(HFSPLUS_SB_FORCE, &sbi->flags);
+		break;
+	default:
+		return -EINVAL;
 	}
 
-	return 1;
+	return 0;
 }
 
 int hfsplus_show_options(struct seq_file *seq, struct dentry *root)
diff --git a/fs/hfsplus/super.c b/fs/hfsplus/super.c
index 97920202790f..948b8aaee33e 100644
--- a/fs/hfsplus/super.c
+++ b/fs/hfsplus/super.c
@@ -14,6 +14,7 @@
 #include <linux/blkdev.h>
 #include <linux/backing-dev.h>
 #include <linux/fs.h>
+#include <linux/fs_context.h>
 #include <linux/slab.h>
 #include <linux/vfs.h>
 #include <linux/nls.h>
@@ -332,34 +333,33 @@ static int hfsplus_statfs(struct dentry *dentry, struct kstatfs *buf)
 	return 0;
 }
 
-static int hfsplus_remount(struct super_block *sb, int *flags, char *data)
+static int hfsplus_reconfigure(struct fs_context *fc)
 {
+	struct super_block *sb = fc->root->d_sb;
+
 	sync_filesystem(sb);
-	if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
+	if ((bool)(fc->sb_flags & SB_RDONLY) == sb_rdonly(sb))
 		return 0;
-	if (!(*flags & SB_RDONLY)) {
-		struct hfsplus_vh *vhdr = HFSPLUS_SB(sb)->s_vhdr;
-		int force = 0;
-
-		if (!hfsplus_parse_options_remount(data, &force))
-			return -EINVAL;
+	if (!(fc->sb_flags & SB_RDONLY)) {
+		struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
+		struct hfsplus_vh *vhdr = sbi->s_vhdr;
 
 		if (!(vhdr->attributes & cpu_to_be32(HFSPLUS_VOL_UNMNT))) {
 			pr_warn("filesystem was not cleanly unmounted, running fsck.hfsplus is recommended.  leaving read-only.\n");
 			sb->s_flags |= SB_RDONLY;
-			*flags |= SB_RDONLY;
-		} else if (force) {
+			fc->sb_flags |= SB_RDONLY;
+		} else if (test_bit(HFSPLUS_SB_FORCE, &sbi->flags)) {
 			/* nothing */
 		} else if (vhdr->attributes &
 				cpu_to_be32(HFSPLUS_VOL_SOFTLOCK)) {
 			pr_warn("filesystem is marked locked, leaving read-only.\n");
 			sb->s_flags |= SB_RDONLY;
-			*flags |= SB_RDONLY;
+			fc->sb_flags |= SB_RDONLY;
 		} else if (vhdr->attributes &
 				cpu_to_be32(HFSPLUS_VOL_JOURNALED)) {
 			pr_warn("filesystem is marked journaled, leaving read-only.\n");
 			sb->s_flags |= SB_RDONLY;
-			*flags |= SB_RDONLY;
+			fc->sb_flags |= SB_RDONLY;
 		}
 	}
 	return 0;
@@ -373,38 +373,33 @@ static const struct super_operations hfsplus_sops = {
 	.put_super	= hfsplus_put_super,
 	.sync_fs	= hfsplus_sync_fs,
 	.statfs		= hfsplus_statfs,
-	.remount_fs	= hfsplus_remount,
 	.show_options	= hfsplus_show_options,
 };
 
-static int hfsplus_fill_super(struct super_block *sb, void *data, int silent)
+static int hfsplus_fill_super(struct super_block *sb, struct fs_context *fc)
 {
 	struct hfsplus_vh *vhdr;
-	struct hfsplus_sb_info *sbi;
+	struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
 	hfsplus_cat_entry entry;
 	struct hfs_find_data fd;
 	struct inode *root, *inode;
 	struct qstr str;
-	struct nls_table *nls = NULL;
+	struct nls_table *nls;
 	u64 last_fs_block, last_fs_page;
+	int silent = fc->sb_flags & SB_SILENT;
 	int err;
 
-	err = -ENOMEM;
-	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
-	if (!sbi)
-		goto out;
-
-	sb->s_fs_info = sbi;
 	mutex_init(&sbi->alloc_mutex);
 	mutex_init(&sbi->vh_mutex);
 	spin_lock_init(&sbi->work_lock);
 	INIT_DELAYED_WORK(&sbi->sync_work, delayed_sync_fs);
-	hfsplus_fill_defaults(sbi);
 
 	err = -EINVAL;
-	if (!hfsplus_parse_options(data, sbi)) {
-		pr_err("unable to parse mount options\n");
-		goto out_unload_nls;
+	if (!sbi->nls) {
+		/* try utf8 first, as this is the old default behaviour */
+		sbi->nls = load_nls("utf8");
+		if (!sbi->nls)
+			sbi->nls = load_nls_default();
 	}
 
 	/* temporarily use utf8 to correctly find the hidden dir below */
@@ -616,7 +611,6 @@ out_unload_nls:
 	unload_nls(sbi->nls);
 	unload_nls(nls);
 	kfree(sbi);
-out:
 	return err;
 }
 
@@ -641,18 +635,46 @@ static void hfsplus_free_inode(struct inode *inode)
 
 #define HFSPLUS_INODE_SIZE	sizeof(struct hfsplus_inode_info)
 
-static struct dentry *hfsplus_mount(struct file_system_type *fs_type,
-			  int flags, const char *dev_name, void *data)
+static int hfsplus_get_tree(struct fs_context *fc)
+{
+	return get_tree_bdev(fc, hfsplus_fill_super);
+}
+
+static void hfsplus_free_fc(struct fs_context *fc)
 {
-	return mount_bdev(fs_type, flags, dev_name, data, hfsplus_fill_super);
+	kfree(fc->s_fs_info);
+}
+
+static const struct fs_context_operations hfsplus_context_ops = {
+	.parse_param	= hfsplus_parse_param,
+	.get_tree	= hfsplus_get_tree,
+	.reconfigure	= hfsplus_reconfigure,
+	.free		= hfsplus_free_fc,
+};
+
+static int hfsplus_init_fs_context(struct fs_context *fc)
+{
+	struct hfsplus_sb_info *sbi;
+
+	sbi = kzalloc(sizeof(struct hfsplus_sb_info), GFP_KERNEL);
+	if (!sbi)
+		return -ENOMEM;
+
+	if (fc->purpose != FS_CONTEXT_FOR_RECONFIGURE)
+		hfsplus_fill_defaults(sbi);
+
+	fc->s_fs_info = sbi;
+	fc->ops = &hfsplus_context_ops;
+
+	return 0;
 }
 
 static struct file_system_type hfsplus_fs_type = {
 	.owner		= THIS_MODULE,
 	.name		= "hfsplus",
-	.mount		= hfsplus_mount,
 	.kill_sb	= kill_block_super,
 	.fs_flags	= FS_REQUIRES_DEV,
+	.init_fs_context = hfsplus_init_fs_context,
 };
 MODULE_ALIAS_FS("hfsplus");