diff mbox series

[V2] hfs: convert hfs to use the new mount api

Message ID 66accd3d-b293-4aeb-abdf-483a7d17b963@redhat.com (mailing list archive)
State New
Headers show
Series [V2] hfs: convert hfs to use the new mount api | expand

Commit Message

Eric Sandeen Oct. 8, 2024, 12:52 p.m. UTC
Convert the hfs filesystem to use the new mount API.
Tested by comparing random mount & remount options before and after
the change, and trivial I/O tests.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
---

V2: attach sb to sbi (sbi->sb = sb) in fill_super as before

Brown paper bag time, I really only tested mount/unmount, and because
I had forgotten to attach sb back to sbi (sbi->sb = sb) in fill_super(),
actual IO failed in flush_mdb() as reported by syzbot at
https://lore.kernel.org/all/6700d799.050a0220.49194.04b3.GAE@google.com/T/

Really sorry about that. Since it's a small functional change, I removed
Jan's RVB for V2.

Comments

Christian Brauner Oct. 8, 2024, 1:08 p.m. UTC | #1
On Tue, Oct 08, 2024 at 07:52:48AM GMT, Eric Sandeen wrote:
> Convert the hfs filesystem to use the new mount API.
> Tested by comparing random mount & remount options before and after
> the change, and trivial I/O tests.
> 
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
> ---
> 
> V2: attach sb to sbi (sbi->sb = sb) in fill_super as before
> 
> Brown paper bag time, I really only tested mount/unmount, and because

We don't do brown paper bags here. Making people fix their bugs is
the real punishment. :)

> I had forgotten to attach sb back to sbi (sbi->sb = sb) in fill_super(),

I already folded that fix into your earlier patch.
Eric Sandeen Oct. 8, 2024, 3:21 p.m. UTC | #2
On 10/8/24 8:08 AM, Christian Brauner wrote:
> On Tue, Oct 08, 2024 at 07:52:48AM GMT, Eric Sandeen wrote:
>> Convert the hfs filesystem to use the new mount API.
>> Tested by comparing random mount & remount options before and after
>> the change, and trivial I/O tests.
>>
>> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
>> ---
>>
>> V2: attach sb to sbi (sbi->sb = sb) in fill_super as before
>>
>> Brown paper bag time, I really only tested mount/unmount, and because
> 
> We don't do brown paper bags here. Making people fix their bugs is
> the real punishment. :)

Fair ;)

>> I had forgotten to attach sb back to sbi (sbi->sb = sb) in fill_super(),
> 
> I already folded that fix into your earlier patch.
> 

Thank you!

-Eric
diff mbox series

Patch

diff --git a/fs/hfs/super.c b/fs/hfs/super.c
index eeac99765f0d..3bee9b5dba5e 100644
--- a/fs/hfs/super.c
+++ b/fs/hfs/super.c
@@ -15,10 +15,11 @@ 
 #include <linux/module.h>
 #include <linux/blkdev.h>
 #include <linux/backing-dev.h>
+#include <linux/fs_context.h>
+#include <linux/fs_parser.h>
 #include <linux/mount.h>
 #include <linux/init.h>
 #include <linux/nls.h>
-#include <linux/parser.h>
 #include <linux/seq_file.h>
 #include <linux/slab.h>
 #include <linux/vfs.h>
@@ -111,21 +112,24 @@  static int hfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 	return 0;
 }
 
-static int hfs_remount(struct super_block *sb, int *flags, char *data)
+static int hfs_reconfigure(struct fs_context *fc)
 {
+	struct super_block *sb = fc->root->d_sb;
+
 	sync_filesystem(sb);
-	*flags |= SB_NODIRATIME;
-	if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
+	fc->sb_flags |= SB_NODIRATIME;
+	if ((bool)(fc->sb_flags & SB_RDONLY) == sb_rdonly(sb))
 		return 0;
-	if (!(*flags & SB_RDONLY)) {
+
+	if (!(fc->sb_flags & SB_RDONLY)) {
 		if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
 			pr_warn("filesystem was not cleanly unmounted, running fsck.hfs is recommended.  leaving read-only.\n");
 			sb->s_flags |= SB_RDONLY;
-			*flags |= SB_RDONLY;
+			fc->sb_flags |= SB_RDONLY;
 		} else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {
 			pr_warn("filesystem is marked locked, leaving read-only.\n");
 			sb->s_flags |= SB_RDONLY;
-			*flags |= SB_RDONLY;
+			fc->sb_flags |= SB_RDONLY;
 		}
 	}
 	return 0;
@@ -180,7 +184,6 @@  static const struct super_operations hfs_super_operations = {
 	.put_super	= hfs_put_super,
 	.sync_fs	= hfs_sync_fs,
 	.statfs		= hfs_statfs,
-	.remount_fs     = hfs_remount,
 	.show_options	= hfs_show_options,
 };
 
@@ -188,181 +191,112 @@  enum {
 	opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
 	opt_part, opt_session, opt_type, opt_creator, opt_quiet,
 	opt_codepage, opt_iocharset,
-	opt_err
 };
 
-static const match_table_t tokens = {
-	{ opt_uid, "uid=%u" },
-	{ opt_gid, "gid=%u" },
-	{ opt_umask, "umask=%o" },
-	{ opt_file_umask, "file_umask=%o" },
-	{ opt_dir_umask, "dir_umask=%o" },
-	{ opt_part, "part=%u" },
-	{ opt_session, "session=%u" },
-	{ opt_type, "type=%s" },
-	{ opt_creator, "creator=%s" },
-	{ opt_quiet, "quiet" },
-	{ opt_codepage, "codepage=%s" },
-	{ opt_iocharset, "iocharset=%s" },
-	{ opt_err, NULL }
+static const struct fs_parameter_spec hfs_param_spec[] = {
+	fsparam_u32	("uid",		opt_uid),
+	fsparam_u32	("gid",		opt_gid),
+	fsparam_u32oct	("umask",	opt_umask),
+	fsparam_u32oct	("file_umask",	opt_file_umask),
+	fsparam_u32oct	("dir_umask",	opt_dir_umask),
+	fsparam_u32	("part",	opt_part),
+	fsparam_u32	("session",	opt_session),
+	fsparam_string	("type",	opt_type),
+	fsparam_string	("creator",	opt_creator),
+	fsparam_flag	("quiet",	opt_quiet),
+	fsparam_string	("codepage",	opt_codepage),
+	fsparam_string	("iocharset",	opt_iocharset),
+	{}
 };
 
-static inline int match_fourchar(substring_t *arg, u32 *result)
-{
-	if (arg->to - arg->from != 4)
-		return -EINVAL;
-	memcpy(result, arg->from, 4);
-	return 0;
-}
-
 /*
- * parse_options()
+ * hfs_parse_param()
  *
- * adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger
- * This function is called by hfs_read_super() to parse the mount options.
+ * This function is called by the vfs to parse the mount options.
  */
-static int parse_options(char *options, struct hfs_sb_info *hsb)
+static int hfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
 {
-	char *p;
-	substring_t args[MAX_OPT_ARGS];
-	int tmp, token;
-
-	/* initialize the sb with defaults */
-	hsb->s_uid = current_uid();
-	hsb->s_gid = current_gid();
-	hsb->s_file_umask = 0133;
-	hsb->s_dir_umask = 0022;
-	hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f);	/* == '????' */
-	hsb->s_quiet = 0;
-	hsb->part = -1;
-	hsb->session = -1;
-
-	if (!options)
-		return 1;
-
-	while ((p = strsep(&options, ",")) != NULL) {
-		if (!*p)
-			continue;
-
-		token = match_token(p, tokens, args);
-		switch (token) {
-		case opt_uid:
-			if (match_int(&args[0], &tmp)) {
-				pr_err("uid requires an argument\n");
-				return 0;
-			}
-			hsb->s_uid = make_kuid(current_user_ns(), (uid_t)tmp);
-			if (!uid_valid(hsb->s_uid)) {
-				pr_err("invalid uid %d\n", tmp);
-				return 0;
-			}
-			break;
-		case opt_gid:
-			if (match_int(&args[0], &tmp)) {
-				pr_err("gid requires an argument\n");
-				return 0;
-			}
-			hsb->s_gid = make_kgid(current_user_ns(), (gid_t)tmp);
-			if (!gid_valid(hsb->s_gid)) {
-				pr_err("invalid gid %d\n", tmp);
-				return 0;
-			}
-			break;
-		case opt_umask:
-			if (match_octal(&args[0], &tmp)) {
-				pr_err("umask requires a value\n");
-				return 0;
-			}
-			hsb->s_file_umask = (umode_t)tmp;
-			hsb->s_dir_umask = (umode_t)tmp;
-			break;
-		case opt_file_umask:
-			if (match_octal(&args[0], &tmp)) {
-				pr_err("file_umask requires a value\n");
-				return 0;
-			}
-			hsb->s_file_umask = (umode_t)tmp;
-			break;
-		case opt_dir_umask:
-			if (match_octal(&args[0], &tmp)) {
-				pr_err("dir_umask requires a value\n");
-				return 0;
-			}
-			hsb->s_dir_umask = (umode_t)tmp;
-			break;
-		case opt_part:
-			if (match_int(&args[0], &hsb->part)) {
-				pr_err("part requires an argument\n");
-				return 0;
-			}
-			break;
-		case opt_session:
-			if (match_int(&args[0], &hsb->session)) {
-				pr_err("session requires an argument\n");
-				return 0;
-			}
-			break;
-		case opt_type:
-			if (match_fourchar(&args[0], &hsb->s_type)) {
-				pr_err("type requires a 4 character value\n");
-				return 0;
-			}
-			break;
-		case opt_creator:
-			if (match_fourchar(&args[0], &hsb->s_creator)) {
-				pr_err("creator requires a 4 character value\n");
-				return 0;
-			}
-			break;
-		case opt_quiet:
-			hsb->s_quiet = 1;
-			break;
-		case opt_codepage:
-			if (hsb->nls_disk) {
-				pr_err("unable to change codepage\n");
-				return 0;
-			}
-			p = match_strdup(&args[0]);
-			if (p)
-				hsb->nls_disk = load_nls(p);
-			if (!hsb->nls_disk) {
-				pr_err("unable to load codepage \"%s\"\n", p);
-				kfree(p);
-				return 0;
-			}
-			kfree(p);
-			break;
-		case opt_iocharset:
-			if (hsb->nls_io) {
-				pr_err("unable to change iocharset\n");
-				return 0;
-			}
-			p = match_strdup(&args[0]);
-			if (p)
-				hsb->nls_io = load_nls(p);
-			if (!hsb->nls_io) {
-				pr_err("unable to load iocharset \"%s\"\n", p);
-				kfree(p);
-				return 0;
-			}
-			kfree(p);
-			break;
-		default:
-			return 0;
-		}
-	}
+	struct hfs_sb_info *hsb = fc->s_fs_info;
+	struct fs_parse_result result;
+	int opt;
+
+	/* hfs does not honor any fs-specific options on remount */
+	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE)
+		return 0;
 
-	if (hsb->nls_disk && !hsb->nls_io) {
-		hsb->nls_io = load_nls_default();
+	opt = fs_parse(fc, hfs_param_spec, param, &result);
+	if (opt < 0)
+		return opt;
+
+	switch (opt) {
+	case opt_uid:
+		hsb->s_uid = result.uid;
+		break;
+	case opt_gid:
+		hsb->s_gid = result.gid;
+		break;
+	case opt_umask:
+		hsb->s_file_umask = (umode_t)result.uint_32;
+		hsb->s_dir_umask = (umode_t)result.uint_32;
+		break;
+	case opt_file_umask:
+		hsb->s_file_umask = (umode_t)result.uint_32;
+		break;
+	case opt_dir_umask:
+		hsb->s_dir_umask = (umode_t)result.uint_32;
+		break;
+	case opt_part:
+		hsb->part = result.uint_32;
+		break;
+	case opt_session:
+		hsb->session = result.uint_32;
+		break;
+	case opt_type:
+		if (strlen(param->string) != 4) {
+			pr_err("type requires a 4 character value\n");
+			return -EINVAL;
+		}
+		memcpy(&hsb->s_type, param->string, 4);
+		break;
+	case opt_creator:
+		if (strlen(param->string) != 4) {
+			pr_err("creator requires a 4 character value\n");
+			return -EINVAL;
+		}
+		memcpy(&hsb->s_creator, param->string, 4);
+		break;
+	case opt_quiet:
+		hsb->s_quiet = 1;
+		break;
+	case opt_codepage:
+		if (hsb->nls_disk) {
+			pr_err("unable to change codepage\n");
+			return -EINVAL;
+		}
+		hsb->nls_disk = load_nls(param->string);
+		if (!hsb->nls_disk) {
+			pr_err("unable to load codepage \"%s\"\n",
+					param->string);
+			return -EINVAL;
+		}
+		break;
+	case opt_iocharset:
+		if (hsb->nls_io) {
+			pr_err("unable to change iocharset\n");
+			return -EINVAL;
+		}
+		hsb->nls_io = load_nls(param->string);
 		if (!hsb->nls_io) {
-			pr_err("unable to load default iocharset\n");
-			return 0;
+			pr_err("unable to load iocharset \"%s\"\n",
+					param->string);
+			return -EINVAL;
 		}
+		break;
+	default:
+		return -EINVAL;
 	}
-	hsb->s_dir_umask &= 0777;
-	hsb->s_file_umask &= 0577;
 
-	return 1;
+	return 0;
 }
 
 /*
@@ -376,29 +310,25 @@  static int parse_options(char *options, struct hfs_sb_info *hsb)
  * hfs_btree_init() to get the necessary data about the extents and
  * catalog B-trees and, finally, reading the root inode into memory.
  */
-static int hfs_fill_super(struct super_block *sb, void *data, int silent)
+static int hfs_fill_super(struct super_block *sb, struct fs_context *fc)
 {
-	struct hfs_sb_info *sbi;
+	struct hfs_sb_info *sbi = HFS_SB(sb);
 	struct hfs_find_data fd;
 	hfs_cat_rec rec;
 	struct inode *root_inode;
+	int silent = fc->sb_flags & SB_SILENT;
 	int res;
 
-	sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
-	if (!sbi)
-		return -ENOMEM;
+	/* load_nls_default does not fail */
+	if (sbi->nls_disk && !sbi->nls_io)
+		sbi->nls_io = load_nls_default();
+	sbi->s_dir_umask &= 0777;
+	sbi->s_file_umask &= 0577;
 
-	sbi->sb = sb;
-	sb->s_fs_info = sbi;
 	spin_lock_init(&sbi->work_lock);
 	INIT_DELAYED_WORK(&sbi->mdb_work, flush_mdb);
 
-	res = -EINVAL;
-	if (!parse_options((char *)data, sbi)) {
-		pr_err("unable to parse mount options\n");
-		goto bail;
-	}
-
+	sbi->sb = sb;
 	sb->s_op = &hfs_super_operations;
 	sb->s_xattr = hfs_xattr_handlers;
 	sb->s_flags |= SB_NODIRATIME;
@@ -451,18 +381,56 @@  static int hfs_fill_super(struct super_block *sb, void *data, int silent)
 	return res;
 }
 
-static struct dentry *hfs_mount(struct file_system_type *fs_type,
-		      int flags, const char *dev_name, void *data)
+static int hfs_get_tree(struct fs_context *fc)
+{
+	return get_tree_bdev(fc, hfs_fill_super);
+}
+
+static void hfs_free_fc(struct fs_context *fc)
+{
+	kfree(fc->s_fs_info);
+}
+
+static const struct fs_context_operations hfs_context_ops = {
+	.parse_param	= hfs_parse_param,
+	.get_tree	= hfs_get_tree,
+	.reconfigure	= hfs_reconfigure,
+	.free		= hfs_free_fc,
+};
+
+static int hfs_init_fs_context(struct fs_context *fc)
 {
-	return mount_bdev(fs_type, flags, dev_name, data, hfs_fill_super);
+	struct hfs_sb_info *hsb;
+
+	hsb = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
+	if (!hsb)
+		return -ENOMEM;
+
+	fc->s_fs_info = hsb;
+	fc->ops = &hfs_context_ops;
+
+	if (fc->purpose != FS_CONTEXT_FOR_RECONFIGURE) {
+		/* initialize options with defaults */
+		hsb->s_uid = current_uid();
+		hsb->s_gid = current_gid();
+		hsb->s_file_umask = 0133;
+		hsb->s_dir_umask = 0022;
+		hsb->s_type = cpu_to_be32(0x3f3f3f3f); /* == '????' */
+		hsb->s_creator = cpu_to_be32(0x3f3f3f3f); /* == '????' */
+		hsb->s_quiet = 0;
+		hsb->part = -1;
+		hsb->session = -1;
+	}
+
+	return 0;
 }
 
 static struct file_system_type hfs_fs_type = {
 	.owner		= THIS_MODULE,
 	.name		= "hfs",
-	.mount		= hfs_mount,
 	.kill_sb	= kill_block_super,
 	.fs_flags	= FS_REQUIRES_DEV,
+	.init_fs_context = hfs_init_fs_context,
 };
 MODULE_ALIAS_FS("hfs");