Merge tag 'exfat-for-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/exfat

Pull exfat updates from Namjae Jeon:

 - Add keep_last_dots mount option to allow access to paths with
   trailing dots

 - Avoid repetitive volume dirty bit set/clear to improve storage life
   time

* tag 'exfat-for-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/exfat:
  exfat: do not clear VolumeDirty in writeback
  exfat: allow access to paths with trailing dots

4 files changed, 47 insertions, 30 deletions

diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h
index 619e5b4bed10..c6800b880920 100644
--- a/fs/exfat/exfat_fs.h
+++ b/fs/exfat/exfat_fs.h
@@ -203,7 +203,8 @@ struct exfat_mount_options {
 	/* on error: continue, panic, remount-ro */
 	enum exfat_error_mode errors;
 	unsigned utf8:1, /* Use of UTF-8 character set */
-		 discard:1; /* Issue discard requests on deletions */
+		 discard:1, /* Issue discard requests on deletions */
+		 keep_last_dots:1; /* Keep trailing periods in paths */
 	int time_offset; /* Offset of timestamps from UTC (in minutes) */
 };
 
diff --git a/fs/exfat/file.c b/fs/exfat/file.c
index d890fd34bb2d..2f5130059236 100644
--- a/fs/exfat/file.c
+++ b/fs/exfat/file.c
@@ -218,8 +218,6 @@ int __exfat_truncate(struct inode *inode, loff_t new_size)
 	if (exfat_free_cluster(inode, &clu))
 		return -EIO;
 
-	exfat_clear_volume_dirty(sb);
-
 	return 0;
 }
 
diff --git a/fs/exfat/namei.c b/fs/exfat/namei.c
index af4eb39cc0c3..a02a04a993bf 100644
--- a/fs/exfat/namei.c
+++ b/fs/exfat/namei.c
@@ -65,11 +65,14 @@ static int exfat_d_revalidate(struct dentry *dentry, unsigned int flags)
 	return ret;
 }
 
-/* returns the length of a struct qstr, ignoring trailing dots */
-static unsigned int exfat_striptail_len(unsigned int len, const char *name)
+/* returns the length of a struct qstr, ignoring trailing dots if necessary */
+static unsigned int exfat_striptail_len(unsigned int len, const char *name,
+					bool keep_last_dots)
 {
-	while (len && name[len - 1] == '.')
-		len--;
+	if (!keep_last_dots) {
+		while (len && name[len - 1] == '.')
+			len--;
+	}
 	return len;
 }
 
@@ -83,7 +86,8 @@ static int exfat_d_hash(const struct dentry *dentry, struct qstr *qstr)
 	struct super_block *sb = dentry->d_sb;
 	struct nls_table *t = EXFAT_SB(sb)->nls_io;
 	const unsigned char *name = qstr->name;
-	unsigned int len = exfat_striptail_len(qstr->len, qstr->name);
+	unsigned int len = exfat_striptail_len(qstr->len, qstr->name,
+			   EXFAT_SB(sb)->options.keep_last_dots);
 	unsigned long hash = init_name_hash(dentry);
 	int i, charlen;
 	wchar_t c;
@@ -104,8 +108,10 @@ static int exfat_d_cmp(const struct dentry *dentry, unsigned int len,
 {
 	struct super_block *sb = dentry->d_sb;
 	struct nls_table *t = EXFAT_SB(sb)->nls_io;
-	unsigned int alen = exfat_striptail_len(name->len, name->name);
-	unsigned int blen = exfat_striptail_len(len, str);
+	unsigned int alen = exfat_striptail_len(name->len, name->name,
+				EXFAT_SB(sb)->options.keep_last_dots);
+	unsigned int blen = exfat_striptail_len(len, str,
+				EXFAT_SB(sb)->options.keep_last_dots);
 	wchar_t c1, c2;
 	int charlen, i;
 
@@ -136,7 +142,8 @@ static int exfat_utf8_d_hash(const struct dentry *dentry, struct qstr *qstr)
 {
 	struct super_block *sb = dentry->d_sb;
 	const unsigned char *name = qstr->name;
-	unsigned int len = exfat_striptail_len(qstr->len, qstr->name);
+	unsigned int len = exfat_striptail_len(qstr->len, qstr->name,
+			       EXFAT_SB(sb)->options.keep_last_dots);
 	unsigned long hash = init_name_hash(dentry);
 	int i, charlen;
 	unicode_t u;
@@ -161,8 +168,11 @@ static int exfat_utf8_d_cmp(const struct dentry *dentry, unsigned int len,
 		const char *str, const struct qstr *name)
 {
 	struct super_block *sb = dentry->d_sb;
-	unsigned int alen = exfat_striptail_len(name->len, name->name);
-	unsigned int blen = exfat_striptail_len(len, str);
+	unsigned int alen = exfat_striptail_len(name->len, name->name,
+				EXFAT_SB(sb)->options.keep_last_dots);
+	unsigned int blen = exfat_striptail_len(len, str,
+				EXFAT_SB(sb)->options.keep_last_dots);
+
 	unicode_t u_a, u_b;
 	int charlen, i;
 
@@ -416,13 +426,25 @@ static int __exfat_resolve_path(struct inode *inode, const unsigned char *path,
 	struct super_block *sb = inode->i_sb;
 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
 	struct exfat_inode_info *ei = EXFAT_I(inode);
+	int pathlen = strlen(path);
 
-	/* strip all trailing periods */
-	namelen = exfat_striptail_len(strlen(path), path);
+	/*
+	 * get the length of the pathname excluding
+	 * trailing periods, if any.
+	 */
+	namelen = exfat_striptail_len(pathlen, path, false);
+	if (EXFAT_SB(sb)->options.keep_last_dots) {
+		/*
+		 * Do not allow the creation of files with names
+		 * ending with period(s).
+		 */
+		if (!lookup && (namelen < pathlen))
+			return -EINVAL;
+		namelen = pathlen;
+	}
 	if (!namelen)
 		return -ENOENT;
-
-	if (strlen(path) > (MAX_NAME_LENGTH * MAX_CHARSET_SIZE))
+	if (pathlen > (MAX_NAME_LENGTH * MAX_CHARSET_SIZE))
 		return -ENAMETOOLONG;
 
 	/*
@@ -554,7 +576,6 @@ static int exfat_create(struct user_namespace *mnt_userns, struct inode *dir,
 	exfat_set_volume_dirty(sb);
 	err = exfat_add_entry(dir, dentry->d_name.name, &cdir, TYPE_FILE,
 		&info);
-	exfat_clear_volume_dirty(sb);
 	if (err)
 		goto unlock;
 
@@ -812,7 +833,6 @@ static int exfat_unlink(struct inode *dir, struct dentry *dentry)
 
 	/* This doesn't modify ei */
 	ei->dir.dir = DIR_DELETED;
-	exfat_clear_volume_dirty(sb);
 
 	inode_inc_iversion(dir);
 	dir->i_mtime = dir->i_atime = current_time(dir);
@@ -846,7 +866,6 @@ static int exfat_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
 	exfat_set_volume_dirty(sb);
 	err = exfat_add_entry(dir, dentry->d_name.name, &cdir, TYPE_DIR,
 		&info);
-	exfat_clear_volume_dirty(sb);
 	if (err)
 		goto unlock;
 
@@ -976,7 +995,6 @@ static int exfat_rmdir(struct inode *dir, struct dentry *dentry)
 		goto unlock;
 	}
 	ei->dir.dir = DIR_DELETED;
-	exfat_clear_volume_dirty(sb);
 
 	inode_inc_iversion(dir);
 	dir->i_mtime = dir->i_atime = current_time(dir);
@@ -1311,7 +1329,6 @@ del_out:
 		 */
 		new_ei->dir.dir = DIR_DELETED;
 	}
-	exfat_clear_volume_dirty(sb);
 out:
 	return ret;
 }
diff --git a/fs/exfat/super.c b/fs/exfat/super.c
index 9f892903419a..8ca21e7917d1 100644
--- a/fs/exfat/super.c
+++ b/fs/exfat/super.c
@@ -100,7 +100,6 @@ static int exfat_set_vol_flags(struct super_block *sb, unsigned short new_flags)
 {
 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
 	struct boot_sector *p_boot = (struct boot_sector *)sbi->boot_bh->b_data;
-	bool sync;
 
 	/* retain persistent-flags */
 	new_flags |= sbi->vol_flags_persistent;
@@ -119,16 +118,11 @@ static int exfat_set_vol_flags(struct super_block *sb, unsigned short new_flags)
 
 	p_boot->vol_flags = cpu_to_le16(new_flags);
 
-	if ((new_flags & VOLUME_DIRTY) && !buffer_dirty(sbi->boot_bh))
-		sync = true;
-	else
-		sync = false;
-
 	set_buffer_uptodate(sbi->boot_bh);
 	mark_buffer_dirty(sbi->boot_bh);
 
-	if (sync)
-		sync_dirty_buffer(sbi->boot_bh);
+	__sync_dirty_buffer(sbi->boot_bh, REQ_SYNC | REQ_FUA | REQ_PREFLUSH);
+
 	return 0;
 }
 
@@ -174,6 +168,8 @@ static int exfat_show_options(struct seq_file *m, struct dentry *root)
 		seq_puts(m, ",errors=remount-ro");
 	if (opts->discard)
 		seq_puts(m, ",discard");
+	if (opts->keep_last_dots)
+		seq_puts(m, ",keep_last_dots");
 	if (opts->time_offset)
 		seq_printf(m, ",time_offset=%d", opts->time_offset);
 	return 0;
@@ -217,6 +213,7 @@ enum {
 	Opt_charset,
 	Opt_errors,
 	Opt_discard,
+	Opt_keep_last_dots,
 	Opt_time_offset,
 
 	/* Deprecated options */
@@ -243,6 +240,7 @@ static const struct fs_parameter_spec exfat_parameters[] = {
 	fsparam_string("iocharset",		Opt_charset),
 	fsparam_enum("errors",			Opt_errors, exfat_param_enums),
 	fsparam_flag("discard",			Opt_discard),
+	fsparam_flag("keep_last_dots",		Opt_keep_last_dots),
 	fsparam_s32("time_offset",		Opt_time_offset),
 	__fsparam(NULL, "utf8",			Opt_utf8, fs_param_deprecated,
 		  NULL),
@@ -297,6 +295,9 @@ static int exfat_parse_param(struct fs_context *fc, struct fs_parameter *param)
 	case Opt_discard:
 		opts->discard = 1;
 		break;
+	case Opt_keep_last_dots:
+		opts->keep_last_dots = 1;
+		break;
 	case Opt_time_offset:
 		/*
 		 * Make the limit 24 just in case someone invents something