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 <[email protected]>
---
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,
&ep->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, &bh, §or);
@@ -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, &bh, §or);
@@ -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
index 595f3117f492..84664024e51e 100644
--- a/fs/exfat/exfat_fs.h
+++ b/fs/exfat/exfat_fs.h
@@ -13,8 +13,6 @@
#define EXFAT_SUPER_MAGIC 0x2011BAB0UL
#define EXFAT_ROOT_INO 1
-#define EXFAT_SB_DIRTY 0
-
#define EXFAT_CLUSTERS_UNTRACKED (~0u)
/*
@@ -238,7 +236,6 @@ struct exfat_sb_info {
unsigned int clu_srch_ptr; /* cluster search pointer */
unsigned int used_clusters; /* number of used clusters */
- unsigned long s_state;
struct mutex s_lock; /* superblock lock */
struct exfat_mount_options options;
struct nls_table *nls_io; /* Charset used for input and display */
@@ -514,7 +511,7 @@ void exfat_set_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts,
u8 *tz, __le16 *time, __le16 *date, u8 *time_cs);
u16 exfat_calc_chksum16(void *data, int len, u16 chksum, int type);
u32 exfat_calc_chksum32(void *data, int len, u32 chksum, int type);
-void exfat_update_bh(struct super_block *sb, struct buffer_head *bh, int sync);
+void exfat_update_bh(struct buffer_head *bh, int sync);
void exfat_chain_set(struct exfat_chain *ec, unsigned int dir,
unsigned int size, unsigned char flags);
void exfat_chain_dup(struct exfat_chain *dup, struct exfat_chain *ec);
diff --git a/fs/exfat/fatent.c b/fs/exfat/fatent.c
index 4e5c5c9c0f2d..82ee8246c080 100644
--- a/fs/exfat/fatent.c
+++ b/fs/exfat/fatent.c
@@ -75,7 +75,7 @@ int exfat_ent_set(struct super_block *sb, unsigned int loc,
fat_entry = (__le32 *)&(bh->b_data[off]);
*fat_entry = cpu_to_le32(content);
- exfat_update_bh(sb, bh, sb->s_flags & SB_SYNCHRONOUS);
+ exfat_update_bh(bh, sb->s_flags & SB_SYNCHRONOUS);
exfat_mirror_bh(sb, sec, bh);
brelse(bh);
return 0;
@@ -174,7 +174,6 @@ int exfat_free_cluster(struct inode *inode, struct exfat_chain *p_chain)
return -EIO;
}
- set_bit(EXFAT_SB_DIRTY, &sbi->s_state);
clu = p_chain->dir;
if (p_chain->flags == ALLOC_NO_FAT_CHAIN) {
@@ -274,7 +273,7 @@ int exfat_zeroed_cluster(struct inode *dir, unsigned int clu)
goto release_bhs;
}
memset(bhs[n]->b_data, 0, sb->s_blocksize);
- exfat_update_bh(sb, bhs[n], 0);
+ exfat_update_bh(bhs[n], 0);
n++;
blknr++;
@@ -358,8 +357,6 @@ int exfat_alloc_cluster(struct inode *inode, unsigned int num_alloc,
}
}
- set_bit(EXFAT_SB_DIRTY, &sbi->s_state);
-
p_chain->dir = EXFAT_EOF_CLUSTER;
while ((new_clu = exfat_find_free_bitmap(sb, hint_clu)) !=
diff --git a/fs/exfat/misc.c b/fs/exfat/misc.c
index 17d41f3d3709..8a3dde59052b 100644
--- a/fs/exfat/misc.c
+++ b/fs/exfat/misc.c
@@ -163,9 +163,8 @@ u32 exfat_calc_chksum32(void *data, int len, u32 chksum, int type)
return chksum;
}
-void exfat_update_bh(struct super_block *sb, struct buffer_head *bh, int sync)
+void exfat_update_bh(struct buffer_head *bh, int sync)
{
- set_bit(EXFAT_SB_DIRTY, &EXFAT_SB(sb)->s_state);
set_buffer_uptodate(bh);
mark_buffer_dirty(bh);
diff --git a/fs/exfat/namei.c b/fs/exfat/namei.c
index edd8023865a0..5eef2217fcf2 100644
--- a/fs/exfat/namei.c
+++ b/fs/exfat/namei.c
@@ -387,7 +387,7 @@ static int exfat_find_empty_entry(struct inode *inode,
ep->dentry.stream.valid_size = cpu_to_le64(size);
ep->dentry.stream.size = ep->dentry.stream.valid_size;
ep->dentry.stream.flags = p_dir->flags;
- exfat_update_bh(sb, bh, IS_DIRSYNC(inode));
+ exfat_update_bh(bh, IS_DIRSYNC(inode));
brelse(bh);
if (exfat_update_dir_chksum(inode, &(ei->dir),
ei->entry))
@@ -1071,7 +1071,7 @@ static int exfat_rename_file(struct inode *inode, struct exfat_chain *p_dir,
epnew->dentry.file.attr |= cpu_to_le16(ATTR_ARCHIVE);
ei->attr |= ATTR_ARCHIVE;
}
- exfat_update_bh(sb, new_bh, sync);
+ exfat_update_bh(new_bh, sync);
brelse(old_bh);
brelse(new_bh);
@@ -1087,7 +1087,7 @@ static int exfat_rename_file(struct inode *inode, struct exfat_chain *p_dir,
}
memcpy(epnew, epold, DENTRY_SIZE);
- exfat_update_bh(sb, new_bh, sync);
+ exfat_update_bh(new_bh, sync);
brelse(old_bh);
brelse(new_bh);
@@ -1104,7 +1104,7 @@ static int exfat_rename_file(struct inode *inode, struct exfat_chain *p_dir,
epold->dentry.file.attr |= cpu_to_le16(ATTR_ARCHIVE);
ei->attr |= ATTR_ARCHIVE;
}
- exfat_update_bh(sb, old_bh, sync);
+ exfat_update_bh(old_bh, sync);
brelse(old_bh);
ret = exfat_init_ext_entry(inode, p_dir, oldentry,
num_new_entries, p_uniname);
@@ -1159,7 +1159,7 @@ static int exfat_move_file(struct inode *inode, struct exfat_chain *p_olddir,
epnew->dentry.file.attr |= cpu_to_le16(ATTR_ARCHIVE);
ei->attr |= ATTR_ARCHIVE;
}
- exfat_update_bh(sb, new_bh, IS_DIRSYNC(inode));
+ exfat_update_bh(new_bh, IS_DIRSYNC(inode));
brelse(mov_bh);
brelse(new_bh);
@@ -1175,7 +1175,7 @@ static int exfat_move_file(struct inode *inode, struct exfat_chain *p_olddir,
}
memcpy(epnew, epmov, DENTRY_SIZE);
- exfat_update_bh(sb, new_bh, IS_DIRSYNC(inode));
+ exfat_update_bh(new_bh, IS_DIRSYNC(inode));
brelse(mov_bh);
brelse(new_bh);
diff --git a/fs/exfat/super.c b/fs/exfat/super.c
index e650e65536f8..b2611050b671 100644
--- a/fs/exfat/super.c
+++ b/fs/exfat/super.c
@@ -45,9 +45,6 @@ static void exfat_put_super(struct super_block *sb)
struct exfat_sb_info *sbi = EXFAT_SB(sb);
mutex_lock(&sbi->s_lock);
- if (test_and_clear_bit(EXFAT_SB_DIRTY, &sbi->s_state))
- sync_blockdev(sb->s_bdev);
- exfat_set_vol_flags(sb, VOL_CLEAN);
exfat_free_bitmap(sbi);
brelse(sbi->boot_bh);
mutex_unlock(&sbi->s_lock);
@@ -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(&sbi->s_lock);
- if (test_and_clear_bit(EXFAT_SB_DIRTY, &sbi->s_state)) {
- sync_blockdev(sb->s_bdev);
- if (exfat_set_vol_flags(sb, VOL_CLEAN))
- err = -EIO;
- }
+ sync_blockdev(sb->s_bdev);
+ if (exfat_set_vol_flags(sb, VOL_CLEAN))
+ err = -EIO;
mutex_unlock(&sbi->s_lock);
return err;
}
--
2.25.1
> 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 <[email protected]>
> ---
> 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(&sbi->s_lock);
> - if (test_and_clear_bit(EXFAT_SB_DIRTY, &sbi->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(&sbi->s_lock);
> return err;
> }
> --
> 2.25.1
> 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
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
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 <[email protected]>
>> ---
>> 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(&sbi->s_lock);
>> - if (test_and_clear_bit(EXFAT_SB_DIRTY, &sbi->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(&sbi->s_lock);
>> return err;
>> }
>> --
>> 2.25.1
>
>
BR
---
Tetsuhiro Kohada <[email protected]>
> 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 <[email protected]>
> >> ---
> >> 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(&sbi->s_lock);
> >> - if (test_and_clear_bit(EXFAT_SB_DIRTY, &sbi->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(&sbi->s_lock);
> >> return err;
> >> }
> >> --
> >> 2.25.1
> >
> >
>
> BR
> ---
> Tetsuhiro Kohada <[email protected]>
> > 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 <[email protected]>
> > >> ---
> > >> 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(&sbi->s_lock);
> > >> - if (test_and_clear_bit(EXFAT_SB_DIRTY, &sbi->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(&sbi->s_lock);
> > >> return err;
> > >> }
> > >> --
> > >> 2.25.1
BR
---
Kohada Tetsuhiro <[email protected]>