2014-07-03 10:59:30

by Chao Yu

[permalink] [raw]
Subject: [f2fs-dev][PATCH] f2fs: reduce competition among node page writes

We do not need to block on ->node_write among different node page writers e.g.
fsync/flush, unless we have a node page writer from write_checkpoint.
So it's better use rw_semaphore instead of mutex type for ->node_write to
promote performance.

Signed-off-by: Chao Yu <[email protected]>
---
fs/f2fs/checkpoint.c | 6 +++---
fs/f2fs/f2fs.h | 2 +-
fs/f2fs/node.c | 4 ++--
fs/f2fs/super.c | 2 +-
4 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 0b4710c..eec406b 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -714,10 +714,10 @@ retry_flush_dents:
* until finishing nat/sit flush.
*/
retry_flush_nodes:
- mutex_lock(&sbi->node_write);
+ down_write(&sbi->node_write);

if (get_pages(sbi, F2FS_DIRTY_NODES)) {
- mutex_unlock(&sbi->node_write);
+ up_write(&sbi->node_write);
sync_node_pages(sbi, 0, &wbc);
goto retry_flush_nodes;
}
@@ -726,7 +726,7 @@ retry_flush_nodes:

static void unblock_operations(struct f2fs_sb_info *sbi)
{
- mutex_unlock(&sbi->node_write);
+ up_write(&sbi->node_write);
f2fs_unlock_all(sbi);
}

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index ae3b4ac..ca30b5a 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -444,7 +444,7 @@ struct f2fs_sb_info {
struct inode *meta_inode; /* cache meta blocks */
struct mutex cp_mutex; /* checkpoint procedure lock */
struct rw_semaphore cp_rwsem; /* blocking FS operations */
- struct mutex node_write; /* locking node writes */
+ struct rw_semaphore node_write; /* locking node writes */
struct mutex writepages; /* mutex for writepages() */
bool por_doing; /* recovery is doing or not */
wait_queue_head_t cp_wait;
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index a90f51d..7b5b5de 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -1231,12 +1231,12 @@ static int f2fs_write_node_page(struct page *page,
if (wbc->for_reclaim)
goto redirty_out;

- mutex_lock(&sbi->node_write);
+ down_read(&sbi->node_write);
set_page_writeback(page);
write_node_page(sbi, page, &fio, nid, ni.blk_addr, &new_addr);
set_node_addr(sbi, &ni, new_addr, is_fsync_dnode(page));
dec_page_count(sbi, F2FS_DIRTY_NODES);
- mutex_unlock(&sbi->node_write);
+ up_read(&sbi->node_write);
unlock_page(page);
return 0;

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 8f96d93..bed9413 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -947,7 +947,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
mutex_init(&sbi->gc_mutex);
mutex_init(&sbi->writepages);
mutex_init(&sbi->cp_mutex);
- mutex_init(&sbi->node_write);
+ init_rwsem(&sbi->node_write);
sbi->por_doing = false;
spin_lock_init(&sbi->stat_lock);

--
1.7.9.5


2014-07-30 13:08:55

by Chao Yu

[permalink] [raw]
Subject: RE: [f2fs-dev] [PATCH] f2fs: reduce competition among node page writes

Hi Jaegeuk Changman,

> -----Original Message-----
> From: Chao Yu [mailto:[email protected]]
> Sent: Thursday, July 03, 2014 6:59 PM
> To: Jaegeuk Kim; Changman Lee
> Cc: [email protected]; [email protected];
> [email protected]
> Subject: [f2fs-dev] [PATCH] f2fs: reduce competition among node page writes
>
> We do not need to block on ->node_write among different node page writers e.g.
> fsync/flush, unless we have a node page writer from write_checkpoint.
> So it's better use rw_semaphore instead of mutex type for ->node_write to
> promote performance.

If you could have time to help explaining the problem of this patch, I will be
appreciated for that.

Another question is what is ->writepages in sbi used for? I'm not quite clear.

Thanks,

>
> Signed-off-by: Chao Yu <[email protected]>
> ---
> fs/f2fs/checkpoint.c | 6 +++---
> fs/f2fs/f2fs.h | 2 +-
> fs/f2fs/node.c | 4 ++--
> fs/f2fs/super.c | 2 +-
> 4 files changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
> index 0b4710c..eec406b 100644
> --- a/fs/f2fs/checkpoint.c
> +++ b/fs/f2fs/checkpoint.c
> @@ -714,10 +714,10 @@ retry_flush_dents:
> * until finishing nat/sit flush.
> */
> retry_flush_nodes:
> - mutex_lock(&sbi->node_write);
> + down_write(&sbi->node_write);
>
> if (get_pages(sbi, F2FS_DIRTY_NODES)) {
> - mutex_unlock(&sbi->node_write);
> + up_write(&sbi->node_write);
> sync_node_pages(sbi, 0, &wbc);
> goto retry_flush_nodes;
> }
> @@ -726,7 +726,7 @@ retry_flush_nodes:
>
> static void unblock_operations(struct f2fs_sb_info *sbi)
> {
> - mutex_unlock(&sbi->node_write);
> + up_write(&sbi->node_write);
> f2fs_unlock_all(sbi);
> }
>
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index ae3b4ac..ca30b5a 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -444,7 +444,7 @@ struct f2fs_sb_info {
> struct inode *meta_inode; /* cache meta blocks */
> struct mutex cp_mutex; /* checkpoint procedure lock */
> struct rw_semaphore cp_rwsem; /* blocking FS operations */
> - struct mutex node_write; /* locking node writes */
> + struct rw_semaphore node_write; /* locking node writes */
> struct mutex writepages; /* mutex for writepages() */
> bool por_doing; /* recovery is doing or not */
> wait_queue_head_t cp_wait;
> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> index a90f51d..7b5b5de 100644
> --- a/fs/f2fs/node.c
> +++ b/fs/f2fs/node.c
> @@ -1231,12 +1231,12 @@ static int f2fs_write_node_page(struct page *page,
> if (wbc->for_reclaim)
> goto redirty_out;
>
> - mutex_lock(&sbi->node_write);
> + down_read(&sbi->node_write);
> set_page_writeback(page);
> write_node_page(sbi, page, &fio, nid, ni.blk_addr, &new_addr);
> set_node_addr(sbi, &ni, new_addr, is_fsync_dnode(page));
> dec_page_count(sbi, F2FS_DIRTY_NODES);
> - mutex_unlock(&sbi->node_write);
> + up_read(&sbi->node_write);
> unlock_page(page);
> return 0;
>
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index 8f96d93..bed9413 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -947,7 +947,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
> mutex_init(&sbi->gc_mutex);
> mutex_init(&sbi->writepages);
> mutex_init(&sbi->cp_mutex);
> - mutex_init(&sbi->node_write);
> + init_rwsem(&sbi->node_write);
> sbi->por_doing = false;
> spin_lock_init(&sbi->stat_lock);
>
> --
> 1.7.9.5
>
>
>
> ------------------------------------------------------------------------------
> Open source business process management suite built on Java and Eclipse
> Turn processes into business applications with Bonita BPM Community Edition
> Quickly connect people, data, and systems into organized workflows
> Winner of BOSSIE, CODIE, OW2 and Gartner awards
> http://p.sf.net/sfu/Bonitasoft
> _______________________________________________
> Linux-f2fs-devel mailing list
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

2014-07-31 02:08:42

by Changman Lee

[permalink] [raw]
Subject: Re: [f2fs-dev] [PATCH] f2fs: reduce competition among node page writes

Hi Chao,

On Wed, Jul 30, 2014 at 09:07:49PM +0800, Chao Yu wrote:
> Hi Jaegeuk Changman,
>
> > -----Original Message-----
> > From: Chao Yu [mailto:[email protected]]
> > Sent: Thursday, July 03, 2014 6:59 PM
> > To: Jaegeuk Kim; Changman Lee
> > Cc: [email protected]; [email protected];
> > [email protected]
> > Subject: [f2fs-dev] [PATCH] f2fs: reduce competition among node page writes
> >
> > We do not need to block on ->node_write among different node page writers e.g.
> > fsync/flush, unless we have a node page writer from write_checkpoint.
> > So it's better use rw_semaphore instead of mutex type for ->node_write to
> > promote performance.
>
> If you could have time to help explaining the problem of this patch, I will be
> appreciated for that.

I have no clue. Except checkpoint, I don't know why need to block to
write node page.
Do you have any problem when you test with this patch?

>
> Another question is what is ->writepages in sbi used for? I'm not quite clear.
>

I remember it is for writing data pages per thread as much as possible.
When multi-threads write some files simultaneously, multi-threads contended with
each other to allocate a block. So block allocation was interleaved
across threads. It makes fragmentation of file.

Thanks,

> Thanks,
>
> >
> > Signed-off-by: Chao Yu <[email protected]>
> > ---
> > fs/f2fs/checkpoint.c | 6 +++---
> > fs/f2fs/f2fs.h | 2 +-
> > fs/f2fs/node.c | 4 ++--
> > fs/f2fs/super.c | 2 +-
> > 4 files changed, 7 insertions(+), 7 deletions(-)
> >
> > diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
> > index 0b4710c..eec406b 100644
> > --- a/fs/f2fs/checkpoint.c
> > +++ b/fs/f2fs/checkpoint.c
> > @@ -714,10 +714,10 @@ retry_flush_dents:
> > * until finishing nat/sit flush.
> > */
> > retry_flush_nodes:
> > - mutex_lock(&sbi->node_write);
> > + down_write(&sbi->node_write);
> >
> > if (get_pages(sbi, F2FS_DIRTY_NODES)) {
> > - mutex_unlock(&sbi->node_write);
> > + up_write(&sbi->node_write);
> > sync_node_pages(sbi, 0, &wbc);
> > goto retry_flush_nodes;
> > }
> > @@ -726,7 +726,7 @@ retry_flush_nodes:
> >
> > static void unblock_operations(struct f2fs_sb_info *sbi)
> > {
> > - mutex_unlock(&sbi->node_write);
> > + up_write(&sbi->node_write);
> > f2fs_unlock_all(sbi);
> > }
> >
> > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> > index ae3b4ac..ca30b5a 100644
> > --- a/fs/f2fs/f2fs.h
> > +++ b/fs/f2fs/f2fs.h
> > @@ -444,7 +444,7 @@ struct f2fs_sb_info {
> > struct inode *meta_inode; /* cache meta blocks */
> > struct mutex cp_mutex; /* checkpoint procedure lock */
> > struct rw_semaphore cp_rwsem; /* blocking FS operations */
> > - struct mutex node_write; /* locking node writes */
> > + struct rw_semaphore node_write; /* locking node writes */
> > struct mutex writepages; /* mutex for writepages() */
> > bool por_doing; /* recovery is doing or not */
> > wait_queue_head_t cp_wait;
> > diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> > index a90f51d..7b5b5de 100644
> > --- a/fs/f2fs/node.c
> > +++ b/fs/f2fs/node.c
> > @@ -1231,12 +1231,12 @@ static int f2fs_write_node_page(struct page *page,
> > if (wbc->for_reclaim)
> > goto redirty_out;
> >
> > - mutex_lock(&sbi->node_write);
> > + down_read(&sbi->node_write);
> > set_page_writeback(page);
> > write_node_page(sbi, page, &fio, nid, ni.blk_addr, &new_addr);
> > set_node_addr(sbi, &ni, new_addr, is_fsync_dnode(page));
> > dec_page_count(sbi, F2FS_DIRTY_NODES);
> > - mutex_unlock(&sbi->node_write);
> > + up_read(&sbi->node_write);
> > unlock_page(page);
> > return 0;
> >
> > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> > index 8f96d93..bed9413 100644
> > --- a/fs/f2fs/super.c
> > +++ b/fs/f2fs/super.c
> > @@ -947,7 +947,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
> > mutex_init(&sbi->gc_mutex);
> > mutex_init(&sbi->writepages);
> > mutex_init(&sbi->cp_mutex);
> > - mutex_init(&sbi->node_write);
> > + init_rwsem(&sbi->node_write);
> > sbi->por_doing = false;
> > spin_lock_init(&sbi->stat_lock);
> >
> > --
> > 1.7.9.5
> >
> >
> >
> > ------------------------------------------------------------------------------
> > Open source business process management suite built on Java and Eclipse
> > Turn processes into business applications with Bonita BPM Community Edition
> > Quickly connect people, data, and systems into organized workflows
> > Winner of BOSSIE, CODIE, OW2 and Gartner awards
> > http://p.sf.net/sfu/Bonitasoft
> > _______________________________________________
> > Linux-f2fs-devel mailing list
> > [email protected]
> > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

2014-07-31 05:32:44

by Chao Yu

[permalink] [raw]
Subject: RE: [f2fs-dev] [PATCH] f2fs: reduce competition among node page writes

Hi Changman,

> -----Original Message-----
> From: Changman Lee [mailto:[email protected]]
> Sent: Thursday, July 31, 2014 10:07 AM
> To: Chao Yu
> Cc: 'Jaegeuk Kim'; [email protected]; [email protected];
> [email protected]
> Subject: Re: [f2fs-dev] [PATCH] f2fs: reduce competition among node page writes
>
> Hi Chao,
>
> On Wed, Jul 30, 2014 at 09:07:49PM +0800, Chao Yu wrote:
> > Hi Jaegeuk Changman,
> >
> > > -----Original Message-----
> > > From: Chao Yu [mailto:[email protected]]
> > > Sent: Thursday, July 03, 2014 6:59 PM
> > > To: Jaegeuk Kim; Changman Lee
> > > Cc: [email protected]; [email protected];
> > > [email protected]
> > > Subject: [f2fs-dev] [PATCH] f2fs: reduce competition among node page writes
> > >
> > > We do not need to block on ->node_write among different node page writers e.g.
> > > fsync/flush, unless we have a node page writer from write_checkpoint.
> > > So it's better use rw_semaphore instead of mutex type for ->node_write to
> > > promote performance.
> >
> > If you could have time to help explaining the problem of this patch, I will be
> > appreciated for that.
>
> I have no clue. Except checkpoint, I don't know why need to block to
> write node page.
> Do you have any problem when you test with this patch?

I don't have.
I send this patch about one month ago, but got no respond.
So I want to ask if any problem in this patch or forget to look at this patch?

To Jaegeuk:
Any idea about this patch?

>
> >
> > Another question is what is ->writepages in sbi used for? I'm not quite clear.
> >
>
> I remember it is for writing data pages per thread as much as possible.
> When multi-threads write some files simultaneously, multi-threads contended with
> each other to allocate a block. So block allocation was interleaved
> across threads. It makes fragmentation of file.

Thank you for the explanation! :)
I think what you say is reasonable.

Previously I tested without this lock, although I found that the blocks written
_almost_ were continuous in each '->writepages()'. Still I think we can gain more
from readahead continuous block when using this lock, rather than remove it for
promoting concurrent of writers.

Thanks,
Yu

>
> Thanks,
>
> > Thanks,
> >
> > >
> > > Signed-off-by: Chao Yu <[email protected]>
> > > ---
> > > fs/f2fs/checkpoint.c | 6 +++---
> > > fs/f2fs/f2fs.h | 2 +-
> > > fs/f2fs/node.c | 4 ++--
> > > fs/f2fs/super.c | 2 +-
> > > 4 files changed, 7 insertions(+), 7 deletions(-)
> > >
> > > diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
> > > index 0b4710c..eec406b 100644
> > > --- a/fs/f2fs/checkpoint.c
> > > +++ b/fs/f2fs/checkpoint.c
> > > @@ -714,10 +714,10 @@ retry_flush_dents:
> > > * until finishing nat/sit flush.
> > > */
> > > retry_flush_nodes:
> > > - mutex_lock(&sbi->node_write);
> > > + down_write(&sbi->node_write);
> > >
> > > if (get_pages(sbi, F2FS_DIRTY_NODES)) {
> > > - mutex_unlock(&sbi->node_write);
> > > + up_write(&sbi->node_write);
> > > sync_node_pages(sbi, 0, &wbc);
> > > goto retry_flush_nodes;
> > > }
> > > @@ -726,7 +726,7 @@ retry_flush_nodes:
> > >
> > > static void unblock_operations(struct f2fs_sb_info *sbi)
> > > {
> > > - mutex_unlock(&sbi->node_write);
> > > + up_write(&sbi->node_write);
> > > f2fs_unlock_all(sbi);
> > > }
> > >
> > > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> > > index ae3b4ac..ca30b5a 100644
> > > --- a/fs/f2fs/f2fs.h
> > > +++ b/fs/f2fs/f2fs.h
> > > @@ -444,7 +444,7 @@ struct f2fs_sb_info {
> > > struct inode *meta_inode; /* cache meta blocks */
> > > struct mutex cp_mutex; /* checkpoint procedure lock */
> > > struct rw_semaphore cp_rwsem; /* blocking FS operations */
> > > - struct mutex node_write; /* locking node writes */
> > > + struct rw_semaphore node_write; /* locking node writes */
> > > struct mutex writepages; /* mutex for writepages() */
> > > bool por_doing; /* recovery is doing or not */
> > > wait_queue_head_t cp_wait;
> > > diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> > > index a90f51d..7b5b5de 100644
> > > --- a/fs/f2fs/node.c
> > > +++ b/fs/f2fs/node.c
> > > @@ -1231,12 +1231,12 @@ static int f2fs_write_node_page(struct page *page,
> > > if (wbc->for_reclaim)
> > > goto redirty_out;
> > >
> > > - mutex_lock(&sbi->node_write);
> > > + down_read(&sbi->node_write);
> > > set_page_writeback(page);
> > > write_node_page(sbi, page, &fio, nid, ni.blk_addr, &new_addr);
> > > set_node_addr(sbi, &ni, new_addr, is_fsync_dnode(page));
> > > dec_page_count(sbi, F2FS_DIRTY_NODES);
> > > - mutex_unlock(&sbi->node_write);
> > > + up_read(&sbi->node_write);
> > > unlock_page(page);
> > > return 0;
> > >
> > > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> > > index 8f96d93..bed9413 100644
> > > --- a/fs/f2fs/super.c
> > > +++ b/fs/f2fs/super.c
> > > @@ -947,7 +947,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
> > > mutex_init(&sbi->gc_mutex);
> > > mutex_init(&sbi->writepages);
> > > mutex_init(&sbi->cp_mutex);
> > > - mutex_init(&sbi->node_write);
> > > + init_rwsem(&sbi->node_write);
> > > sbi->por_doing = false;
> > > spin_lock_init(&sbi->stat_lock);
> > >
> > > --
> > > 1.7.9.5
> > >
> > >
> > >
> > > ------------------------------------------------------------------------------
> > > Open source business process management suite built on Java and Eclipse
> > > Turn processes into business applications with Bonita BPM Community Edition
> > > Quickly connect people, data, and systems into organized workflows
> > > Winner of BOSSIE, CODIE, OW2 and Gartner awards
> > > http://p.sf.net/sfu/Bonitasoft
> > > _______________________________________________
> > > Linux-f2fs-devel mailing list
> > > [email protected]
> > > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

2014-07-31 06:44:52

by Jaegeuk Kim

[permalink] [raw]
Subject: Re: [f2fs-dev] [PATCH] f2fs: reduce competition among node page writes

On Thu, Jul 31, 2014 at 01:31:46PM +0800, Chao Yu wrote:
> Hi Changman,
>
> > -----Original Message-----
> > From: Changman Lee [mailto:[email protected]]
> > Sent: Thursday, July 31, 2014 10:07 AM
> > To: Chao Yu
> > Cc: 'Jaegeuk Kim'; [email protected]; [email protected];
> > [email protected]
> > Subject: Re: [f2fs-dev] [PATCH] f2fs: reduce competition among node page writes
> >
> > Hi Chao,
> >
> > On Wed, Jul 30, 2014 at 09:07:49PM +0800, Chao Yu wrote:
> > > Hi Jaegeuk Changman,
> > >
> > > > -----Original Message-----
> > > > From: Chao Yu [mailto:[email protected]]
> > > > Sent: Thursday, July 03, 2014 6:59 PM
> > > > To: Jaegeuk Kim; Changman Lee
> > > > Cc: [email protected]; [email protected];
> > > > [email protected]
> > > > Subject: [f2fs-dev] [PATCH] f2fs: reduce competition among node page writes
> > > >
> > > > We do not need to block on ->node_write among different node page writers e.g.
> > > > fsync/flush, unless we have a node page writer from write_checkpoint.
> > > > So it's better use rw_semaphore instead of mutex type for ->node_write to
> > > > promote performance.
> > >
> > > If you could have time to help explaining the problem of this patch, I will be
> > > appreciated for that.
> >
> > I have no clue. Except checkpoint, I don't know why need to block to
> > write node page.
> > Do you have any problem when you test with this patch?
>
> I don't have.
> I send this patch about one month ago, but got no respond.
> So I want to ask if any problem in this patch or forget to look at this patch?
>
> To Jaegeuk:
> Any idea about this patch?

Oh, I forgot to send an email for this.
At that time, when I looked at a glance, I thought that it was not clear why
this should be merged.

But, when I contemplate again, it seems that several fsync threads could produce
multiple node writers, resulting in some mutex contention.
Just for sure, can you verify that?

Nevertheless, I think there would be no problem to merge this patch now.
Merged.

>
> >
> > >
> > > Another question is what is ->writepages in sbi used for? I'm not quite clear.
> > >
> >
> > I remember it is for writing data pages per thread as much as possible.
> > When multi-threads write some files simultaneously, multi-threads contended with
> > each other to allocate a block. So block allocation was interleaved
> > across threads. It makes fragmentation of file.

Good. :)

>
> Thank you for the explanation! :)
> I think what you say is reasonable.
>
> Previously I tested without this lock, although I found that the blocks written
> _almost_ were continuous in each '->writepages()'. Still I think we can gain more
> from readahead continuous block when using this lock, rather than remove it for
> promoting concurrent of writers.
>
> Thanks,
> Yu
>
> >
> > Thanks,
> >
> > > Thanks,
> > >
> > > >
> > > > Signed-off-by: Chao Yu <[email protected]>
> > > > ---
> > > > fs/f2fs/checkpoint.c | 6 +++---
> > > > fs/f2fs/f2fs.h | 2 +-
> > > > fs/f2fs/node.c | 4 ++--
> > > > fs/f2fs/super.c | 2 +-
> > > > 4 files changed, 7 insertions(+), 7 deletions(-)
> > > >
> > > > diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
> > > > index 0b4710c..eec406b 100644
> > > > --- a/fs/f2fs/checkpoint.c
> > > > +++ b/fs/f2fs/checkpoint.c
> > > > @@ -714,10 +714,10 @@ retry_flush_dents:
> > > > * until finishing nat/sit flush.
> > > > */
> > > > retry_flush_nodes:
> > > > - mutex_lock(&sbi->node_write);
> > > > + down_write(&sbi->node_write);
> > > >
> > > > if (get_pages(sbi, F2FS_DIRTY_NODES)) {
> > > > - mutex_unlock(&sbi->node_write);
> > > > + up_write(&sbi->node_write);
> > > > sync_node_pages(sbi, 0, &wbc);
> > > > goto retry_flush_nodes;
> > > > }
> > > > @@ -726,7 +726,7 @@ retry_flush_nodes:
> > > >
> > > > static void unblock_operations(struct f2fs_sb_info *sbi)
> > > > {
> > > > - mutex_unlock(&sbi->node_write);
> > > > + up_write(&sbi->node_write);
> > > > f2fs_unlock_all(sbi);
> > > > }
> > > >
> > > > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> > > > index ae3b4ac..ca30b5a 100644
> > > > --- a/fs/f2fs/f2fs.h
> > > > +++ b/fs/f2fs/f2fs.h
> > > > @@ -444,7 +444,7 @@ struct f2fs_sb_info {
> > > > struct inode *meta_inode; /* cache meta blocks */
> > > > struct mutex cp_mutex; /* checkpoint procedure lock */
> > > > struct rw_semaphore cp_rwsem; /* blocking FS operations */
> > > > - struct mutex node_write; /* locking node writes */
> > > > + struct rw_semaphore node_write; /* locking node writes */
> > > > struct mutex writepages; /* mutex for writepages() */
> > > > bool por_doing; /* recovery is doing or not */
> > > > wait_queue_head_t cp_wait;
> > > > diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> > > > index a90f51d..7b5b5de 100644
> > > > --- a/fs/f2fs/node.c
> > > > +++ b/fs/f2fs/node.c
> > > > @@ -1231,12 +1231,12 @@ static int f2fs_write_node_page(struct page *page,
> > > > if (wbc->for_reclaim)
> > > > goto redirty_out;
> > > >
> > > > - mutex_lock(&sbi->node_write);
> > > > + down_read(&sbi->node_write);
> > > > set_page_writeback(page);
> > > > write_node_page(sbi, page, &fio, nid, ni.blk_addr, &new_addr);
> > > > set_node_addr(sbi, &ni, new_addr, is_fsync_dnode(page));
> > > > dec_page_count(sbi, F2FS_DIRTY_NODES);
> > > > - mutex_unlock(&sbi->node_write);
> > > > + up_read(&sbi->node_write);
> > > > unlock_page(page);
> > > > return 0;
> > > >
> > > > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> > > > index 8f96d93..bed9413 100644
> > > > --- a/fs/f2fs/super.c
> > > > +++ b/fs/f2fs/super.c
> > > > @@ -947,7 +947,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
> > > > mutex_init(&sbi->gc_mutex);
> > > > mutex_init(&sbi->writepages);
> > > > mutex_init(&sbi->cp_mutex);
> > > > - mutex_init(&sbi->node_write);
> > > > + init_rwsem(&sbi->node_write);
> > > > sbi->por_doing = false;
> > > > spin_lock_init(&sbi->stat_lock);
> > > >
> > > > --
> > > > 1.7.9.5
> > > >
> > > >
> > > >
> > > > ------------------------------------------------------------------------------
> > > > Open source business process management suite built on Java and Eclipse
> > > > Turn processes into business applications with Bonita BPM Community Edition
> > > > Quickly connect people, data, and systems into organized workflows
> > > > Winner of BOSSIE, CODIE, OW2 and Gartner awards
> > > > http://p.sf.net/sfu/Bonitasoft
> > > > _______________________________________________
> > > > Linux-f2fs-devel mailing list
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