2020-04-08 07:58:19

by [email protected]

[permalink] [raw]
Subject: [PATCH v2] exfat: replace 'time_ms' with 'time_10ms'

Replace "time_ms" with "time_10ms" in the file directory entry structure
and related functions.

The unit of create_time_ms/modify_time_ms in File Directory Entry are
not 'milli-second', but 'centi-second'.

The reason for using 10ms instead of cs for the names is that the exfat
specification defines it as Create10msIncrement/LastModified10msIncrement.

Signed-off-by: Tetsuhiro Kohada <[email protected]>
---
Changes in v2:
- fix spelling mistakes in commit-log.

fs/exfat/dir.c | 8 ++++----
fs/exfat/exfat_fs.h | 4 ++--
fs/exfat/exfat_raw.h | 4 ++--
fs/exfat/file.c | 2 +-
fs/exfat/inode.c | 4 ++--
fs/exfat/misc.c | 18 +++++++++---------
fs/exfat/namei.c | 4 ++--
7 files changed, 22 insertions(+), 22 deletions(-)

diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c
index 4b91afb0f0..cacc53ff11 100644
--- a/fs/exfat/dir.c
+++ b/fs/exfat/dir.c
@@ -137,12 +137,12 @@ static int exfat_readdir(struct inode *inode, struct exfat_dir_entry *dir_entry)
ep->dentry.file.create_tz,
ep->dentry.file.create_time,
ep->dentry.file.create_date,
- ep->dentry.file.create_time_ms);
+ ep->dentry.file.create_time_10ms);
exfat_get_entry_time(sbi, &dir_entry->mtime,
ep->dentry.file.modify_tz,
ep->dentry.file.modify_time,
ep->dentry.file.modify_date,
- ep->dentry.file.modify_time_ms);
+ ep->dentry.file.modify_time_10ms);
exfat_get_entry_time(sbi, &dir_entry->atime,
ep->dentry.file.access_tz,
ep->dentry.file.access_time,
@@ -461,12 +461,12 @@ int exfat_init_dir_entry(struct inode *inode, struct exfat_chain *p_dir,
&ep->dentry.file.create_tz,
&ep->dentry.file.create_time,
&ep->dentry.file.create_date,
- &ep->dentry.file.create_time_ms);
+ &ep->dentry.file.create_time_10ms);
exfat_set_entry_time(sbi, &ts,
&ep->dentry.file.modify_tz,
&ep->dentry.file.modify_time,
&ep->dentry.file.modify_date,
- &ep->dentry.file.modify_time_ms);
+ &ep->dentry.file.modify_time_10ms);
exfat_set_entry_time(sbi, &ts,
&ep->dentry.file.access_tz,
&ep->dentry.file.access_time,
diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h
index 67d4e46fb8..6d357e9f5b 100644
--- a/fs/exfat/exfat_fs.h
+++ b/fs/exfat/exfat_fs.h
@@ -506,9 +506,9 @@ void __exfat_fs_error(struct super_block *sb, int report, const char *fmt, ...)
void exfat_msg(struct super_block *sb, const char *lv, const char *fmt, ...)
__printf(3, 4) __cold;
void exfat_get_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts,
- u8 tz, __le16 time, __le16 date, u8 time_ms);
+ u8 tz, __le16 time, __le16 date, u8 time_10ms);
void exfat_set_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts,
- u8 *tz, __le16 *time, __le16 *date, u8 *time_ms);
+ u8 *tz, __le16 *time, __le16 *date, u8 *time_10ms);
unsigned short exfat_calc_chksum_2byte(void *data, int len,
unsigned short chksum, int type);
void exfat_update_bh(struct super_block *sb, struct buffer_head *bh, int sync);
diff --git a/fs/exfat/exfat_raw.h b/fs/exfat/exfat_raw.h
index 2a841010e6..be0e362422 100644
--- a/fs/exfat/exfat_raw.h
+++ b/fs/exfat/exfat_raw.h
@@ -136,8 +136,8 @@ struct exfat_dentry {
__le16 modify_date;
__le16 access_time;
__le16 access_date;
- __u8 create_time_ms;
- __u8 modify_time_ms;
+ __u8 create_time_10ms;
+ __u8 modify_time_10ms;
__u8 create_tz;
__u8 modify_tz;
__u8 access_tz;
diff --git a/fs/exfat/file.c b/fs/exfat/file.c
index 483f683757..a986f1eeef 100644
--- a/fs/exfat/file.c
+++ b/fs/exfat/file.c
@@ -165,7 +165,7 @@ int __exfat_truncate(struct inode *inode, loff_t new_size)
&ep->dentry.file.modify_tz,
&ep->dentry.file.modify_time,
&ep->dentry.file.modify_date,
- &ep->dentry.file.modify_time_ms);
+ &ep->dentry.file.modify_time_10ms);
ep->dentry.file.attr = cpu_to_le16(ei->attr);

/* File size should be zero if there is no cluster allocated */
diff --git a/fs/exfat/inode.c b/fs/exfat/inode.c
index 06887492f5..59b50dfbdd 100644
--- a/fs/exfat/inode.c
+++ b/fs/exfat/inode.c
@@ -56,12 +56,12 @@ static int __exfat_write_inode(struct inode *inode, int sync)
&ep->dentry.file.create_tz,
&ep->dentry.file.create_time,
&ep->dentry.file.create_date,
- &ep->dentry.file.create_time_ms);
+ &ep->dentry.file.create_time_10ms);
exfat_set_entry_time(sbi, &inode->i_mtime,
&ep->dentry.file.modify_tz,
&ep->dentry.file.modify_time,
&ep->dentry.file.modify_date,
- &ep->dentry.file.modify_time_ms);
+ &ep->dentry.file.modify_time_10ms);
exfat_set_entry_time(sbi, &inode->i_atime,
&ep->dentry.file.access_tz,
&ep->dentry.file.access_time,
diff --git a/fs/exfat/misc.c b/fs/exfat/misc.c
index 14a3300848..8b39c8176a 100644
--- a/fs/exfat/misc.c
+++ b/fs/exfat/misc.c
@@ -75,7 +75,7 @@ static void exfat_adjust_tz(struct timespec64 *ts, u8 tz_off)

/* Convert a EXFAT time/date pair to a UNIX date (seconds since 1 1 70). */
void exfat_get_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts,
- u8 tz, __le16 time, __le16 date, u8 time_ms)
+ u8 tz, __le16 time, __le16 date, u8 time_10ms)
{
u16 t = le16_to_cpu(time);
u16 d = le16_to_cpu(date);
@@ -84,10 +84,10 @@ void exfat_get_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts,
t >> 11, (t >> 5) & 0x003F, (t & 0x001F) << 1);


- /* time_ms field represent 0 ~ 199(1990 ms) */
- if (time_ms) {
- ts->tv_sec += time_ms / 100;
- ts->tv_nsec = (time_ms % 100) * 10 * NSEC_PER_MSEC;
+ /* time_10ms field represent 0 ~ 199cs(1990 ms) */
+ if (time_10ms) {
+ ts->tv_sec += (time_10ms * 10) / 1000;
+ ts->tv_nsec = (time_10ms * 10) % 1000 * NSEC_PER_MSEC;
}

if (tz & EXFAT_TZ_VALID)
@@ -100,7 +100,7 @@ void exfat_get_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts,

/* Convert linear UNIX date to a EXFAT time/date pair. */
void exfat_set_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts,
- u8 *tz, __le16 *time, __le16 *date, u8 *time_ms)
+ u8 *tz, __le16 *time, __le16 *date, u8 *time_10ms)
{
struct tm tm;
u16 t, d;
@@ -112,9 +112,9 @@ void exfat_set_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts,
*time = cpu_to_le16(t);
*date = cpu_to_le16(d);

- /* time_ms field represent 0 ~ 199(1990 ms) */
- if (time_ms)
- *time_ms = (tm.tm_sec & 1) * 100 +
+ /* time_10ms field represent 0 ~ 199cs(1990 ms) */
+ if (time_10ms)
+ *time_10ms = (tm.tm_sec & 1) * 100 +
ts->tv_nsec / (10 * NSEC_PER_MSEC);

/*
diff --git a/fs/exfat/namei.c b/fs/exfat/namei.c
index a8681d91f5..90d8273cd8 100644
--- a/fs/exfat/namei.c
+++ b/fs/exfat/namei.c
@@ -698,12 +698,12 @@ static int exfat_find(struct inode *dir, struct qstr *qname,
ep->dentry.file.create_tz,
ep->dentry.file.create_time,
ep->dentry.file.create_date,
- ep->dentry.file.create_time_ms);
+ ep->dentry.file.create_time_10ms);
exfat_get_entry_time(sbi, &info->mtime,
ep->dentry.file.modify_tz,
ep->dentry.file.modify_time,
ep->dentry.file.modify_date,
- ep->dentry.file.modify_time_ms);
+ ep->dentry.file.modify_time_10ms);
exfat_get_entry_time(sbi, &info->atime,
ep->dentry.file.access_tz,
ep->dentry.file.access_time,
--
2.25.0


2020-04-08 11:24:11

by Matthew Wilcox

[permalink] [raw]
Subject: Re: [PATCH v2] exfat: replace 'time_ms' with 'time_10ms'

Please leave at least 24 hours between sending new versions so that
you can collect all feedback relating to your change, and we don't see
discussion fragment between different threads.

> @@ -84,10 +84,10 @@ void exfat_get_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts,
> t >> 11, (t >> 5) & 0x003F, (t & 0x001F) << 1);
>
>
> - /* time_ms field represent 0 ~ 199(1990 ms) */
> - if (time_ms) {
> - ts->tv_sec += time_ms / 100;
> - ts->tv_nsec = (time_ms % 100) * 10 * NSEC_PER_MSEC;
> + /* time_10ms field represent 0 ~ 199cs(1990 ms) */
> + if (time_10ms) {
> + ts->tv_sec += (time_10ms * 10) / 1000;
> + ts->tv_nsec = (time_10ms * 10) % 1000 * NSEC_PER_MSEC;

I find this more confusing than the original.

ts->tv_sec += time_10ms / 100;
ts->tv_nsec = (time_10ms % 100) * 10 * NSEC_PER_MSEC;

is easier to understand for me, not least because I don't need to worry
about the operator precedence between % and *.

2020-04-13 10:07:40

by [email protected]

[permalink] [raw]
Subject: RE: [PATCH v2] exfat: replace 'time_ms' with 'time_10ms'

> Please leave at least 24 hours between sending new versions so that
> you can collect all feedback relating to your change, and we don't see
> discussion fragment between different threads.

Thanks for good advice!

> > + ts->tv_sec += (time_10ms * 10) / 1000;
> > + ts->tv_nsec = (time_10ms * 10) % 1000 * NSEC_PER_MSEC;
>
> I find this more confusing than the original.

The parentheses were intended to group conversions into milliseconds,
but were not necessary from an "operator precedence" perspective.


>
> ts->tv_sec += time_10ms / 100;
> ts->tv_nsec = (time_10ms % 100) * 10 * NSEC_PER_MSEC;
>
> is easier to understand for me, not least because I don't need to worry
> about the operator precedence between % and *.

If I use '100' for the divisor of '10ms', I find it difficult to understand
the meaning of the operation.

When using '100' for the divisor, I think cs (centi-sec) is easier to understand than 10ms.
Which do you prefer, time_10ms or time_cs?


BR
---
Kohada Tetsuhiro <[email protected]>

2020-04-16 06:49:17

by Namjae Jeon

[permalink] [raw]
Subject: RE: [PATCH v2] exfat: replace 'time_ms' with 'time_10ms'

> > Please leave at least 24 hours between sending new versions so that
> > you can collect all feedback relating to your change, and we don't see
> > discussion fragment between different threads.
>
> Thanks for good advice!
>
> > > + ts->tv_sec += (time_10ms * 10) / 1000;
> > > + ts->tv_nsec = (time_10ms * 10) % 1000 * NSEC_PER_MSEC;
> >
> > I find this more confusing than the original.
>
> The parentheses were intended to group conversions into milliseconds, but
> were not necessary from an "operator precedence" perspective.
>
>
> >
> > ts->tv_sec += time_10ms / 100;
> > ts->tv_nsec = (time_10ms % 100) * 10 * NSEC_PER_MSEC;
> >
> > is easier to understand for me, not least because I don't need to worry
> > about the operator precedence between % and *.
>
> If I use '100' for the divisor of '10ms', I find it difficult to
> understand
> the meaning of the operation.
>
> When using '100' for the divisor, I think cs (centi-sec) is easier to
> understand than 10ms.
> Which do you prefer, time_10ms or time_cs?
Can you resend the patch again after changing to time_cs ?

>
>
> BR
> ---
> Kohada Tetsuhiro <[email protected]>

2020-04-16 07:52:22

by [email protected]

[permalink] [raw]
Subject: RE: [PATCH v2] exfat: replace 'time_ms' with 'time_10ms'

> > When using '100' for the divisor, I think cs (centi-sec) is easier to
> > understand than 10ms.
> > Which do you prefer, time_10ms or time_cs?
> Can you resend the patch again after changing to time_cs ?

Of course.
And, rebase to your for-next.


BR
---
Kohada Tetsuhiro <[email protected]>