RE: [PATCH] exfat: remove EXFAT_SB_DIRTY flag

2020-06-15 Thread kohada.tetsuh...@dc.mitsubishielectric.co.jp
> > On 2020/06/12 17:34, Sungjong Seo wrote:
> > >> remove EXFAT_SB_DIRTY flag and related codes.
> > >>
> > >> This flag is set/reset in exfat_put_super()/exfat_sync_fs() to
> > >> avoid sync_blockdev().
> > >> However ...
> > >> - exfat_put_super():
> > >> Before calling this, the VFS has already called sync_filesystem(),
> > >> so sync is never performed here.
> > >> - exfat_sync_fs():
> > >> After calling this, the VFS calls sync_blockdev(), so, it is
> > >> meaningless to check EXFAT_SB_DIRTY or to bypass sync_blockdev() here.
> > >> Not only that, but in some cases can't clear VOL_DIRTY.
> > >> ex:
> > >> VOL_DIRTY is set when rmdir starts, but when non-empty-dir is
> > >> detected, return error without setting EXFAT_SB_DIRTY.
> > >> If performe 'sync' in this state, VOL_DIRTY will not be cleared.
> > >>
> > >> Remove the EXFAT_SB_DIRTY check to ensure synchronization.
> > >> And, remove the code related to the flag.
> > >>
> > >> Signed-off-by: Tetsuhiro Kohada 
> > >> ---
> > >>   fs/exfat/balloc.c   |  4 ++--
> > >>   fs/exfat/dir.c  | 16 
> > >>   fs/exfat/exfat_fs.h |  5 +
> > >>   fs/exfat/fatent.c   |  7 ++-
> > >>   fs/exfat/misc.c |  3 +--
> > >>   fs/exfat/namei.c| 12 ++--
> > >>   fs/exfat/super.c| 11 +++
> > >>   7 files changed, 23 insertions(+), 35 deletions(-)
> > >>
> > > [snip]
> > >>
> > >> @@ -62,11 +59,9 @@ static int exfat_sync_fs(struct super_block *sb,
> > >> int
> > >> wait)
> > >>
> > >>  /* If there are some dirty buffers in the bdev inode */
> > >>  mutex_lock(>s_lock);
> > >> -if (test_and_clear_bit(EXFAT_SB_DIRTY, >s_state)) {
> > >> -sync_blockdev(sb->s_bdev);
> > >> -if (exfat_set_vol_flags(sb, VOL_CLEAN))
> > >> -err = -EIO;
> > >> -}
> > >
> > > I looked through most codes related to EXFAT_SB_DIRTY and VOL_DIRTY.
> > > And your approach looks good because all of them seem to be
> > > protected by s_lock.
> > >
> > > BTW, as you know, sync_filesystem() calls sync_fs() with 'nowait'
> > > first, and then calls it again with 'wait' twice. No need to sync
> > > with
> > lock twice.
> > > If so, isn't it okay to do nothing when wait is 0?
> >
> > I also think  ‘do nothing when wait is 0’ as you say, but I'm still
> > not sure.
> >
> > Some other Filesystems do nothing with nowait and just return.
> > However, a few Filesystems always perform sync.
> >
> > sync_blockdev() waits for completion, so it may be inappropriate to
> > call with  nowait. (But it was called in the original code)
> >
> > I'm still not sure, so I excluded it in this patch.
> > Is it okay to include it?
> >
> 
> Yes, I think so. sync_filesystem() will call __sync_blockdev() without 'wait' 
> first.
> So, it's enough to call sync_blockdev() with s_lock just one time.

OK.
I will repost v2-patch with the 'wait' check added.
Thanks for your comment.


> > >> +sync_blockdev(sb->s_bdev);
> > >> +if (exfat_set_vol_flags(sb, VOL_CLEAN))
> > >> +err = -EIO;
> > >>  mutex_unlock(>s_lock);
> > >>  return err;
> > >>   }
> > >> --
> > >> 2.25.1

BR
---
Kohada Tetsuhiro 


RE: [PATCH] exfat: remove EXFAT_SB_DIRTY flag

2020-06-14 Thread Sungjong Seo
> On 2020/06/12 17:34, Sungjong Seo wrote:
> >> remove EXFAT_SB_DIRTY flag and related codes.
> >>
> >> This flag is set/reset in exfat_put_super()/exfat_sync_fs() to avoid
> >> sync_blockdev().
> >> However ...
> >> - exfat_put_super():
> >> Before calling this, the VFS has already called sync_filesystem(), so
> >> sync is never performed here.
> >> - exfat_sync_fs():
> >> After calling this, the VFS calls sync_blockdev(), so, it is
> >> meaningless to check EXFAT_SB_DIRTY or to bypass sync_blockdev() here.
> >> Not only that, but in some cases can't clear VOL_DIRTY.
> >> ex:
> >> VOL_DIRTY is set when rmdir starts, but when non-empty-dir is
> >> detected, return error without setting EXFAT_SB_DIRTY.
> >> If performe 'sync' in this state, VOL_DIRTY will not be cleared.
> >>
> >> Remove the EXFAT_SB_DIRTY check to ensure synchronization.
> >> And, remove the code related to the flag.
> >>
> >> Signed-off-by: Tetsuhiro Kohada 
> >> ---
> >>   fs/exfat/balloc.c   |  4 ++--
> >>   fs/exfat/dir.c  | 16 
> >>   fs/exfat/exfat_fs.h |  5 +
> >>   fs/exfat/fatent.c   |  7 ++-
> >>   fs/exfat/misc.c |  3 +--
> >>   fs/exfat/namei.c| 12 ++--
> >>   fs/exfat/super.c| 11 +++
> >>   7 files changed, 23 insertions(+), 35 deletions(-)
> >>
> > [snip]
> >>
> >> @@ -62,11 +59,9 @@ static int exfat_sync_fs(struct super_block *sb,
> >> int
> >> wait)
> >>
> >>/* If there are some dirty buffers in the bdev inode */
> >>mutex_lock(>s_lock);
> >> -  if (test_and_clear_bit(EXFAT_SB_DIRTY, >s_state)) {
> >> -  sync_blockdev(sb->s_bdev);
> >> -  if (exfat_set_vol_flags(sb, VOL_CLEAN))
> >> -  err = -EIO;
> >> -  }
> >
> > I looked through most codes related to EXFAT_SB_DIRTY and VOL_DIRTY.
> > And your approach looks good because all of them seem to be protected
> > by s_lock.
> >
> > BTW, as you know, sync_filesystem() calls sync_fs() with 'nowait'
> > first, and then calls it again with 'wait' twice. No need to sync with
> lock twice.
> > If so, isn't it okay to do nothing when wait is 0?
> 
> I also think  ‘do nothing when wait is 0’ as you say, but I'm still not
> sure.
> 
> Some other Filesystems do nothing with nowait and just return.
> However, a few Filesystems always perform sync.
> 
> sync_blockdev() waits for completion, so it may be inappropriate to call
> with  nowait. (But it was called in the original code)
> 
> I'm still not sure, so I excluded it in this patch.
> Is it okay to include it?
> 

Yes, I think so. sync_filesystem() will call __sync_blockdev() without 'wait' 
first.
So, it's enough to call sync_blockdev() with s_lock just one time.

> 
> >> +  sync_blockdev(sb->s_bdev);
> >> +  if (exfat_set_vol_flags(sb, VOL_CLEAN))
> >> +  err = -EIO;
> >>mutex_unlock(>s_lock);
> >>return err;
> >>   }
> >> --
> >> 2.25.1
> >
> >
> 
> BR
> ---
> Tetsuhiro Kohada 





Re: [PATCH] exfat: remove EXFAT_SB_DIRTY flag

2020-06-12 Thread Tetsuhiro Kohada

On 2020/06/12 17:34, Sungjong Seo wrote:

remove EXFAT_SB_DIRTY flag and related codes.

This flag is set/reset in exfat_put_super()/exfat_sync_fs() to avoid
sync_blockdev().
However ...
- exfat_put_super():
Before calling this, the VFS has already called sync_filesystem(), so sync
is never performed here.
- exfat_sync_fs():
After calling this, the VFS calls sync_blockdev(), so, it is meaningless
to check EXFAT_SB_DIRTY or to bypass sync_blockdev() here.
Not only that, but in some cases can't clear VOL_DIRTY.
ex:
VOL_DIRTY is set when rmdir starts, but when non-empty-dir is detected,
return error without setting EXFAT_SB_DIRTY.
If performe 'sync' in this state, VOL_DIRTY will not be cleared.

Remove the EXFAT_SB_DIRTY check to ensure synchronization.
And, remove the code related to the flag.

Signed-off-by: Tetsuhiro Kohada 
---
  fs/exfat/balloc.c   |  4 ++--
  fs/exfat/dir.c  | 16 
  fs/exfat/exfat_fs.h |  5 +
  fs/exfat/fatent.c   |  7 ++-
  fs/exfat/misc.c |  3 +--
  fs/exfat/namei.c| 12 ++--
  fs/exfat/super.c| 11 +++
  7 files changed, 23 insertions(+), 35 deletions(-)


[snip]


@@ -62,11 +59,9 @@ static int exfat_sync_fs(struct super_block *sb, int
wait)

/* If there are some dirty buffers in the bdev inode */
mutex_lock(>s_lock);
-   if (test_and_clear_bit(EXFAT_SB_DIRTY, >s_state)) {
-   sync_blockdev(sb->s_bdev);
-   if (exfat_set_vol_flags(sb, VOL_CLEAN))
-   err = -EIO;
-   }


I looked through most codes related to EXFAT_SB_DIRTY and VOL_DIRTY.
And your approach looks good because all of them seem to be protected by
s_lock.

BTW, as you know, sync_filesystem() calls sync_fs() with 'nowait' first,
and then calls it again with 'wait' twice. No need to sync with lock twice.
If so, isn't it okay to do nothing when wait is 0?


I also think  ‘do nothing when wait is 0’ as you say, but I'm still not sure.

Some other Filesystems do nothing with nowait and just return.
However, a few Filesystems always perform sync.

sync_blockdev() waits for completion, so it may be inappropriate to call with  
nowait. (But it was called in the original code)

I'm still not sure, so I excluded it in this patch.
Is it okay to include it?



+   sync_blockdev(sb->s_bdev);
+   if (exfat_set_vol_flags(sb, VOL_CLEAN))
+   err = -EIO;
mutex_unlock(>s_lock);
return err;
  }
--
2.25.1





BR
---
Tetsuhiro Kohada 



Re: [PATCH] exfat: remove EXFAT_SB_DIRTY flag

2020-06-12 Thread Greg KH
On Fri, Jun 12, 2020 at 10:48:20AM +0200, Markus Elfring wrote:
> > remove EXFAT_SB_DIRTY flag and related codes.
> 
> I suggest to omit this sentence because a similar information
> is provided a bit later again for this change description.
> 
> 
> > If performe 'sync' in this state, VOL_DIRTY will not be cleared.
> 
> Please improve this wording.
> 
> 
> Would you like to add the tag “Fixes” to the commit message?
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?id=b791d1bdf9212d944d749a5c7ff6febdba241771#n183
> 
> Regards,
> Markus

Hi,

This is the semi-friendly patch-bot of Greg Kroah-Hartman.

Markus, you seem to have sent a nonsensical or otherwise pointless
review comment to a patch submission on a Linux kernel developer mailing
list.  I strongly suggest that you not do this anymore.  Please do not
bother developers who are actively working to produce patches and
features with comments that, in the end, are a waste of time.

Patch submitter, please ignore Markus's suggestion; you do not need to
follow it at all.  The person/bot/AI that sent it is being ignored by
almost all Linux kernel maintainers for having a persistent pattern of
behavior of producing distracting and pointless commentary, and
inability to adapt to feedback.  Please feel free to also ignore emails
from them.

thanks,

greg k-h's patch email bot


Re: [PATCH] exfat: remove EXFAT_SB_DIRTY flag

2020-06-12 Thread Markus Elfring
> remove EXFAT_SB_DIRTY flag and related codes.

I suggest to omit this sentence because a similar information
is provided a bit later again for this change description.


> If performe 'sync' in this state, VOL_DIRTY will not be cleared.

Please improve this wording.


Would you like to add the tag “Fixes” to the commit message?
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?id=b791d1bdf9212d944d749a5c7ff6febdba241771#n183

Regards,
Markus


RE: [PATCH] exfat: remove EXFAT_SB_DIRTY flag

2020-06-12 Thread Sungjong Seo
> remove EXFAT_SB_DIRTY flag and related codes.
> 
> This flag is set/reset in exfat_put_super()/exfat_sync_fs() to avoid
> sync_blockdev().
> However ...
> - exfat_put_super():
> Before calling this, the VFS has already called sync_filesystem(), so sync
> is never performed here.
> - exfat_sync_fs():
> After calling this, the VFS calls sync_blockdev(), so, it is meaningless
> to check EXFAT_SB_DIRTY or to bypass sync_blockdev() here.
> Not only that, but in some cases can't clear VOL_DIRTY.
> ex:
> VOL_DIRTY is set when rmdir starts, but when non-empty-dir is detected,
> return error without setting EXFAT_SB_DIRTY.
> If performe 'sync' in this state, VOL_DIRTY will not be cleared.
> 
> Remove the EXFAT_SB_DIRTY check to ensure synchronization.
> And, remove the code related to the flag.
> 
> Signed-off-by: Tetsuhiro Kohada 
> ---
>  fs/exfat/balloc.c   |  4 ++--
>  fs/exfat/dir.c  | 16 
>  fs/exfat/exfat_fs.h |  5 +
>  fs/exfat/fatent.c   |  7 ++-
>  fs/exfat/misc.c |  3 +--
>  fs/exfat/namei.c| 12 ++--
>  fs/exfat/super.c| 11 +++
>  7 files changed, 23 insertions(+), 35 deletions(-)
> 
[snip]
> 
> @@ -62,11 +59,9 @@ static int exfat_sync_fs(struct super_block *sb, int
> wait)
> 
>   /* If there are some dirty buffers in the bdev inode */
>   mutex_lock(>s_lock);
> - if (test_and_clear_bit(EXFAT_SB_DIRTY, >s_state)) {
> - sync_blockdev(sb->s_bdev);
> - if (exfat_set_vol_flags(sb, VOL_CLEAN))
> - err = -EIO;
> - }

I looked through most codes related to EXFAT_SB_DIRTY and VOL_DIRTY.
And your approach looks good because all of them seem to be protected by
s_lock.

BTW, as you know, sync_filesystem() calls sync_fs() with 'nowait' first,
and then calls it again with 'wait' twice. No need to sync with lock twice.
If so, isn't it okay to do nothing when wait is 0?

> + sync_blockdev(sb->s_bdev);
> + if (exfat_set_vol_flags(sb, VOL_CLEAN))
> + err = -EIO;
>   mutex_unlock(>s_lock);
>   return err;
>  }
> --
> 2.25.1




[PATCH] exfat: remove EXFAT_SB_DIRTY flag

2020-06-11 Thread Tetsuhiro Kohada
remove EXFAT_SB_DIRTY flag and related codes.

This flag is set/reset in exfat_put_super()/exfat_sync_fs()
to avoid sync_blockdev().
However ...
- exfat_put_super():
Before calling this, the VFS has already called sync_filesystem(),
so sync is never performed here.
- exfat_sync_fs():
After calling this, the VFS calls sync_blockdev(), so, it is meaningless
to check EXFAT_SB_DIRTY or to bypass sync_blockdev() here.
Not only that, but in some cases can't clear VOL_DIRTY.
ex:
VOL_DIRTY is set when rmdir starts, but when non-empty-dir is detected,
return error without setting EXFAT_SB_DIRTY.
If performe 'sync' in this state, VOL_DIRTY will not be cleared.

Remove the EXFAT_SB_DIRTY check to ensure synchronization.
And, remove the code related to the flag.

Signed-off-by: Tetsuhiro Kohada 
---
 fs/exfat/balloc.c   |  4 ++--
 fs/exfat/dir.c  | 16 
 fs/exfat/exfat_fs.h |  5 +
 fs/exfat/fatent.c   |  7 ++-
 fs/exfat/misc.c |  3 +--
 fs/exfat/namei.c| 12 ++--
 fs/exfat/super.c| 11 +++
 7 files changed, 23 insertions(+), 35 deletions(-)

diff --git a/fs/exfat/balloc.c b/fs/exfat/balloc.c
index 4055eb00ea9b..a987919686c0 100644
--- a/fs/exfat/balloc.c
+++ b/fs/exfat/balloc.c
@@ -158,7 +158,7 @@ int exfat_set_bitmap(struct inode *inode, unsigned int clu)
b = BITMAP_OFFSET_BIT_IN_SECTOR(sb, ent_idx);
 
set_bit_le(b, sbi->vol_amap[i]->b_data);
-   exfat_update_bh(sb, sbi->vol_amap[i], IS_DIRSYNC(inode));
+   exfat_update_bh(sbi->vol_amap[i], IS_DIRSYNC(inode));
return 0;
 }
 
@@ -180,7 +180,7 @@ void exfat_clear_bitmap(struct inode *inode, unsigned int 
clu)
b = BITMAP_OFFSET_BIT_IN_SECTOR(sb, ent_idx);
 
clear_bit_le(b, sbi->vol_amap[i]->b_data);
-   exfat_update_bh(sb, sbi->vol_amap[i], IS_DIRSYNC(inode));
+   exfat_update_bh(sbi->vol_amap[i], IS_DIRSYNC(inode));
 
if (opts->discard) {
int ret_discard;
diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c
index 8e775bd5d523..02acbb6ddf02 100644
--- a/fs/exfat/dir.c
+++ b/fs/exfat/dir.c
@@ -470,7 +470,7 @@ int exfat_init_dir_entry(struct inode *inode, struct 
exfat_chain *p_dir,
>dentry.file.access_date,
NULL);
 
-   exfat_update_bh(sb, bh, IS_DIRSYNC(inode));
+   exfat_update_bh(bh, IS_DIRSYNC(inode));
brelse(bh);
 
ep = exfat_get_dentry(sb, p_dir, entry + 1, , );
@@ -480,7 +480,7 @@ int exfat_init_dir_entry(struct inode *inode, struct 
exfat_chain *p_dir,
exfat_init_stream_entry(ep,
(type == TYPE_FILE) ? ALLOC_FAT_CHAIN : ALLOC_NO_FAT_CHAIN,
start_clu, size);
-   exfat_update_bh(sb, bh, IS_DIRSYNC(inode));
+   exfat_update_bh(bh, IS_DIRSYNC(inode));
brelse(bh);
 
return 0;
@@ -516,7 +516,7 @@ int exfat_update_dir_chksum(struct inode *inode, struct 
exfat_chain *p_dir,
}
 
fep->dentry.file.checksum = cpu_to_le16(chksum);
-   exfat_update_bh(sb, fbh, IS_DIRSYNC(inode));
+   exfat_update_bh(fbh, IS_DIRSYNC(inode));
 release_fbh:
brelse(fbh);
return ret;
@@ -538,7 +538,7 @@ int exfat_init_ext_entry(struct inode *inode, struct 
exfat_chain *p_dir,
return -EIO;
 
ep->dentry.file.num_ext = (unsigned char)(num_entries - 1);
-   exfat_update_bh(sb, bh, sync);
+   exfat_update_bh(bh, sync);
brelse(bh);
 
ep = exfat_get_dentry(sb, p_dir, entry + 1, , );
@@ -547,7 +547,7 @@ int exfat_init_ext_entry(struct inode *inode, struct 
exfat_chain *p_dir,
 
ep->dentry.stream.name_len = p_uniname->name_len;
ep->dentry.stream.name_hash = cpu_to_le16(p_uniname->name_hash);
-   exfat_update_bh(sb, bh, sync);
+   exfat_update_bh(bh, sync);
brelse(bh);
 
for (i = EXFAT_FIRST_CLUSTER; i < num_entries; i++) {
@@ -556,7 +556,7 @@ int exfat_init_ext_entry(struct inode *inode, struct 
exfat_chain *p_dir,
return -EIO;
 
exfat_init_name_entry(ep, uniname);
-   exfat_update_bh(sb, bh, sync);
+   exfat_update_bh(bh, sync);
brelse(bh);
uniname += EXFAT_FILE_NAME_LEN;
}
@@ -580,7 +580,7 @@ int exfat_remove_entries(struct inode *inode, struct 
exfat_chain *p_dir,
return -EIO;
 
exfat_set_entry_type(ep, TYPE_DELETED);
-   exfat_update_bh(sb, bh, IS_DIRSYNC(inode));
+   exfat_update_bh(bh, IS_DIRSYNC(inode));
brelse(bh);
}
 
@@ -610,7 +610,7 @@ void exfat_free_dentry_set(struct exfat_entry_set_cache 
*es, int sync)
 
for (i = 0; i < es->num_bh; i++) {
if (es->modified)
-   exfat_update_bh(es->sb, es->bh[i], sync);
+   exfat_update_bh(es->bh[i], sync);
brelse(es->bh[i]);
}
kfree(es);
diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h