exfat: support create zero-size directory

This commit adds mount option 'zero_size_dir'. If this option
enabled, don't allocate a cluster to directory when creating
it, and set the directory size to 0.

On Windows, a cluster is allocated for a directory when it is
created, so the mount option is disabled by default.

Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Andy Wu <Andy.Wu@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
This commit is contained in:
Yuezhang Mo 2023-07-20 14:40:08 +08:00 committed by Namjae Jeon
parent dab48b8f2f
commit ee785c15b5
4 changed files with 20 additions and 8 deletions

View file

@ -418,11 +418,13 @@ static void exfat_set_entry_type(struct exfat_dentry *ep, unsigned int type)
}
static void exfat_init_stream_entry(struct exfat_dentry *ep,
unsigned char flags, unsigned int start_clu,
unsigned long long size)
unsigned int start_clu, unsigned long long size)
{
exfat_set_entry_type(ep, TYPE_STREAM);
ep->dentry.stream.flags = flags;
if (size == 0)
ep->dentry.stream.flags = ALLOC_FAT_CHAIN;
else
ep->dentry.stream.flags = ALLOC_NO_FAT_CHAIN;
ep->dentry.stream.start_clu = cpu_to_le32(start_clu);
ep->dentry.stream.valid_size = cpu_to_le64(size);
ep->dentry.stream.size = cpu_to_le64(size);
@ -488,9 +490,7 @@ int exfat_init_dir_entry(struct inode *inode, struct exfat_chain *p_dir,
if (!ep)
return -EIO;
exfat_init_stream_entry(ep,
(type == TYPE_FILE) ? ALLOC_FAT_CHAIN : ALLOC_NO_FAT_CHAIN,
start_clu, size);
exfat_init_stream_entry(ep, start_clu, size);
exfat_update_bh(bh, IS_DIRSYNC(inode));
brelse(bh);

View file

@ -234,6 +234,8 @@ struct exfat_mount_options {
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) */
/* Support creating zero-size directory, default: false */
bool zero_size_dir;
};
/*

View file

@ -518,7 +518,7 @@ static int exfat_add_entry(struct inode *inode, const char *path,
goto out;
}
if (type == TYPE_DIR) {
if (type == TYPE_DIR && !sbi->options.zero_size_dir) {
ret = exfat_alloc_new_dir(inode, &clu);
if (ret)
goto out;
@ -551,7 +551,10 @@ static int exfat_add_entry(struct inode *inode, const char *path,
info->num_subdirs = 0;
} else {
info->attr = EXFAT_ATTR_SUBDIR;
info->start_clu = start_clu;
if (sbi->options.zero_size_dir)
info->start_clu = EXFAT_EOF_CLUSTER;
else
info->start_clu = start_clu;
info->size = clu_size;
info->num_subdirs = EXFAT_MIN_SUBDIR;
}

View file

@ -165,6 +165,8 @@ static int exfat_show_options(struct seq_file *m, struct dentry *root)
seq_puts(m, ",sys_tz");
else if (opts->time_offset)
seq_printf(m, ",time_offset=%d", opts->time_offset);
if (opts->zero_size_dir)
seq_puts(m, ",zero_size_dir");
return 0;
}
@ -209,6 +211,7 @@ enum {
Opt_keep_last_dots,
Opt_sys_tz,
Opt_time_offset,
Opt_zero_size_dir,
/* Deprecated options */
Opt_utf8,
@ -237,6 +240,7 @@ static const struct fs_parameter_spec exfat_parameters[] = {
fsparam_flag("keep_last_dots", Opt_keep_last_dots),
fsparam_flag("sys_tz", Opt_sys_tz),
fsparam_s32("time_offset", Opt_time_offset),
fsparam_flag("zero_size_dir", Opt_zero_size_dir),
__fsparam(NULL, "utf8", Opt_utf8, fs_param_deprecated,
NULL),
__fsparam(NULL, "debug", Opt_debug, fs_param_deprecated,
@ -305,6 +309,9 @@ static int exfat_parse_param(struct fs_context *fc, struct fs_parameter *param)
return -EINVAL;
opts->time_offset = result.int_32;
break;
case Opt_zero_size_dir:
opts->zero_size_dir = true;
break;
case Opt_utf8:
case Opt_debug:
case Opt_namecase: