[PATCH 0/3] Clean up some syntax issue on unzip_vle.c

[PATCH 0/3] Clean up some syntax issue on unzip_vle.c

[Cristian Sicilia]

This patch will do some syntax fix on unzip_vle.c file.
The first patch will produce the removeal of all comparison
with NULL constant prepending not operator for equals comparision.
The second patch move the constant comparison to the right side.
The third align some parameter with the previous parenthesis.

Cristian Sicilia (3):
  staging: erofs: unzip_vle.c: Replace comparison to NULL.
  staging: erofs: unzip_vle.c: Constant in comparison on right side
  staging: erofs: unzip_vle.c: Align parameter to the parentesis

 drivers/staging/erofs/unzip_vle.c | 105 +++++++++++++++++++-------------------
 1 file changed, 53 insertions(+), 52 deletions(-)

-- 
2.7.4

[PATCH 1/3] staging: erofs: unzip_vle.c: Replace comparison to NULL.

[Cristian Sicilia]

Replace equal to NULL with logic unary operator,
and removing not equal to NULL comparison.

Signed-off-by: Cristian Sicilia <sicilia.cristian@gmail.com>
---
 drivers/staging/erofs/unzip_vle.c | 86 +++++++++++++++++++--------------------
 1 file changed, 43 insertions(+), 43 deletions(-)

diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c
index 79d3ba6..1ffeeaa 100644
--- a/drivers/staging/erofs/unzip_vle.c
+++ b/drivers/staging/erofs/unzip_vle.c
@@ -20,8 +20,8 @@ static struct kmem_cache *z_erofs_workgroup_cachep __read_mostly;
 
 void z_erofs_exit_zip_subsystem(void)
 {
-	BUG_ON(z_erofs_workqueue == NULL);
-	BUG_ON(z_erofs_workgroup_cachep == NULL);
+	BUG_ON(!z_erofs_workqueue);
+	BUG_ON(!z_erofs_workgroup_cachep);
 
 	destroy_workqueue(z_erofs_workqueue);
 	kmem_cache_destroy(z_erofs_workgroup_cachep);
@@ -39,7 +39,7 @@ static inline int init_unzip_workqueue(void)
 		WQ_UNBOUND | WQ_HIGHPRI | WQ_CPU_INTENSIVE,
 		onlinecpus + onlinecpus / 4);
 
-	return z_erofs_workqueue != NULL ? 0 : -ENOMEM;
+	return z_erofs_workqueue ? 0 : -ENOMEM;
 }
 
 int __init z_erofs_init_zip_subsystem(void)
@@ -49,7 +49,7 @@ int __init z_erofs_init_zip_subsystem(void)
 		Z_EROFS_WORKGROUP_SIZE, 0,
 		SLAB_RECLAIM_ACCOUNT, NULL);
 
-	if (z_erofs_workgroup_cachep != NULL) {
+	if (z_erofs_workgroup_cachep) {
 		if (!init_unzip_workqueue())
 			return 0;
 
@@ -112,21 +112,21 @@ static bool grab_managed_cache_pages(struct address_space *mapping,
 	for (i = 0; i < clusterblks; ++i) {
 		struct page *page, *found;
 
-		if (READ_ONCE(compressed_pages[i]) != NULL)
+		if (READ_ONCE(compressed_pages[i]))
 			continue;
 
 		page = found = find_get_page(mapping, start + i);
-		if (found == NULL) {
+		if (!found) {
 			noio = false;
 			if (!reserve_allocation)
 				continue;
 			page = EROFS_UNALLOCATED_CACHED_PAGE;
 		}
 
-		if (NULL == cmpxchg(compressed_pages + i, NULL, page))
+		if (!cmpxchg(compressed_pages + i, NULL, page))
 			continue;
 
-		if (found != NULL)
+		if (found)
 			put_page(found);
 	}
 	return noio;
@@ -149,7 +149,7 @@ int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
 	for (i = 0; i < clusterpages; ++i) {
 		struct page *page = grp->compressed_pages[i];
 
-		if (page == NULL || page->mapping != mapping)
+		if (!page || page->mapping != mapping)
 			continue;
 
 		/* block other users from reclaiming or migrating the page */
@@ -210,7 +210,7 @@ static inline bool try_to_reuse_as_compressed_page(
 {
 	while (b->compressed_deficit) {
 		--b->compressed_deficit;
-		if (NULL == cmpxchg(b->compressed_pages++, NULL, page))
+		if (!cmpxchg(b->compressed_pages++, NULL, page))
 			return true;
 	}
 
@@ -293,7 +293,7 @@ z_erofs_vle_work_lookup(const struct z_erofs_vle_work_finder *f)
 	struct z_erofs_vle_work *work;
 
 	egrp = erofs_find_workgroup(f->sb, f->idx, &tag);
-	if (egrp == NULL) {
+	if (!egrp) {
 		*f->grp_ret = NULL;
 		return NULL;
 	}
@@ -366,11 +366,11 @@ z_erofs_vle_work_register(const struct z_erofs_vle_work_finder *f,
 	struct z_erofs_vle_work *work;
 
 	/* if multiref is disabled, grp should never be nullptr */
-	BUG_ON(grp != NULL);
+	BUG_ON(grp);
 
 	/* no available workgroup, let's allocate one */
 	grp = kmem_cache_zalloc(z_erofs_workgroup_cachep, GFP_NOFS);
-	if (unlikely(grp == NULL))
+	if (unlikely(!grp))
 		return ERR_PTR(-ENOMEM);
 
 	grp->obj.index = f->idx;
@@ -431,7 +431,7 @@ static int z_erofs_vle_work_iter_begin(struct z_erofs_vle_work_builder *builder,
 	};
 	struct z_erofs_vle_work *work;
 
-	DBG_BUGON(builder->work != NULL);
+	DBG_BUGON(builder->work);
 
 	/* must be Z_EROFS_WORK_TAIL or the next chained work */
 	DBG_BUGON(*owned_head == Z_EROFS_VLE_WORKGRP_NIL);
@@ -441,7 +441,7 @@ static int z_erofs_vle_work_iter_begin(struct z_erofs_vle_work_builder *builder,
 
 repeat:
 	work = z_erofs_vle_work_lookup(&finder);
-	if (work != NULL) {
+	if (work) {
 		unsigned int orig_llen;
 
 		/* increase workgroup `llen' if needed */
@@ -519,7 +519,7 @@ z_erofs_vle_work_iter_end(struct z_erofs_vle_work_builder *builder)
 {
 	struct z_erofs_vle_work *work = builder->work;
 
-	if (work == NULL)
+	if (!work)
 		return false;
 
 	z_erofs_pagevec_ctor_exit(&builder->vector, false);
@@ -542,7 +542,7 @@ static inline struct page *__stagingpage_alloc(struct list_head *pagepool,
 {
 	struct page *page = erofs_allocpage(pagepool, gfp);
 
-	if (unlikely(page == NULL))
+	if (unlikely(!page))
 		return NULL;
 
 	page->mapping = Z_EROFS_MAPPING_STAGING;
@@ -740,10 +740,10 @@ static inline void z_erofs_vle_read_endio(struct bio *bio)
 		bool cachemngd = false;
 
 		DBG_BUGON(PageUptodate(page));
-		BUG_ON(page->mapping == NULL);
+		BUG_ON(!page->mapping);
 
 #ifdef EROFS_FS_HAS_MANAGED_CACHE
-		if (unlikely(mngda == NULL && !z_erofs_is_stagingpage(page))) {
+		if (unlikely(!mngda && !z_erofs_is_stagingpage(page))) {
 			struct inode *const inode = page->mapping->host;
 			struct super_block *const sb = inode->i_sb;
 
@@ -814,7 +814,7 @@ static int z_erofs_vle_unzip(struct super_block *sb,
 			sizeof(struct page *), GFP_KERNEL);
 
 		/* fallback to global pagemap for the lowmem scenario */
-		if (unlikely(pages == NULL)) {
+		if (unlikely(!pages)) {
 			if (nr_pages > Z_EROFS_VLE_VMAP_GLOBAL_PAGES)
 				goto repeat;
 			else {
@@ -836,8 +836,8 @@ static int z_erofs_vle_unzip(struct super_block *sb,
 		page = z_erofs_pagevec_ctor_dequeue(&ctor, &page_type);
 
 		/* all pages in pagevec ought to be valid */
-		DBG_BUGON(page == NULL);
-		DBG_BUGON(page->mapping == NULL);
+		DBG_BUGON(!page);
+		DBG_BUGON(!page->mapping);
 
 		if (z_erofs_gather_if_stagingpage(page_pool, page))
 			continue;
@@ -848,7 +848,7 @@ static int z_erofs_vle_unzip(struct super_block *sb,
 			pagenr = z_erofs_onlinepage_index(page);
 
 		BUG_ON(pagenr >= nr_pages);
-		BUG_ON(pages[pagenr] != NULL);
+		BUG_ON(pages[pagenr]);
 
 		pages[pagenr] = page;
 	}
@@ -865,8 +865,8 @@ static int z_erofs_vle_unzip(struct super_block *sb,
 		page = compressed_pages[i];
 
 		/* all compressed pages ought to be valid */
-		DBG_BUGON(page == NULL);
-		DBG_BUGON(page->mapping == NULL);
+		DBG_BUGON(!page);
+		DBG_BUGON(!page->mapping);
 
 		if (z_erofs_is_stagingpage(page))
 			continue;
@@ -882,7 +882,7 @@ static int z_erofs_vle_unzip(struct super_block *sb,
 		pagenr = z_erofs_onlinepage_index(page);
 
 		BUG_ON(pagenr >= nr_pages);
-		BUG_ON(pages[pagenr] != NULL);
+		BUG_ON(pages[pagenr]);
 		++sparsemem_pages;
 		pages[pagenr] = page;
 
@@ -915,7 +915,7 @@ static int z_erofs_vle_unzip(struct super_block *sb,
 	}
 
 	for (i = 0; i < nr_pages; ++i) {
-		if (pages[i] != NULL)
+		if (pages[i])
 			continue;
 
 		pages[i] = __stagingpage_alloc(page_pool, GFP_NOFS);
@@ -932,7 +932,7 @@ static int z_erofs_vle_unzip(struct super_block *sb,
 out:
 	for (i = 0; i < nr_pages; ++i) {
 		page = pages[i];
-		DBG_BUGON(page->mapping == NULL);
+		DBG_BUGON(!page->mapping);
 
 		/* recycle all individual staging pages */
 		if (z_erofs_gather_if_stagingpage(page_pool, page))
@@ -1021,20 +1021,20 @@ prepare_io_handler(struct super_block *sb,
 
 	if (!background) {
 		/* waitqueue available for foreground io */
-		BUG_ON(io == NULL);
+		BUG_ON(!io);
 
 		init_waitqueue_head(&io->u.wait);
 		atomic_set(&io->pending_bios, 0);
 		goto out;
 	}
 
-	if (io != NULL)
+	if (io)
 		BUG();
 	else {
 		/* allocate extra io descriptor for background io */
 		iosb = kvzalloc(sizeof(struct z_erofs_vle_unzip_io_sb),
 			GFP_KERNEL | __GFP_NOFAIL);
-		BUG_ON(iosb == NULL);
+		BUG_ON(!iosb);
 
 		io = &iosb->io;
 	}
@@ -1154,7 +1154,7 @@ static bool z_erofs_vle_submit_all(struct super_block *sb,
 		if (page == EROFS_UNALLOCATED_CACHED_PAGE) {
 			cachemngd = true;
 			goto do_allocpage;
-		} else if (page != NULL) {
+		} else if (page) {
 			if (page->mapping != mngda)
 				BUG_ON(PageUptodate(page));
 			else if (recover_managed_page(grp, page)) {
@@ -1166,7 +1166,7 @@ static bool z_erofs_vle_submit_all(struct super_block *sb,
 		} else {
 do_allocpage:
 #else
-		if (page != NULL)
+		if (page)
 			BUG_ON(PageUptodate(page));
 		else {
 #endif
@@ -1185,13 +1185,13 @@ static bool z_erofs_vle_submit_all(struct super_block *sb,
 			}
 		}
 
-		if (bio != NULL && force_submit) {
+		if (bio && force_submit) {
 submit_bio_retry:
 			__submit_bio(bio, REQ_OP_READ, 0);
 			bio = NULL;
 		}
 
-		if (bio == NULL) {
+		if (!bio) {
 			bio = erofs_grab_bio(sb, first_index + i,
 				BIO_MAX_PAGES, z_erofs_vle_read_endio, true);
 			bio->bi_private = tagptr_cast_ptr(bi_private);
@@ -1220,12 +1220,12 @@ static bool z_erofs_vle_submit_all(struct super_block *sb,
 				Z_EROFS_VLE_WORKGRP_TAIL_CLOSED :
 				owned_head;
 
-			if (lstgrp_io == NULL)
+			if (!lstgrp_io)
 				ios[1]->head = iogrp_next;
 			else
 				WRITE_ONCE(lstgrp_io->next, iogrp_next);
 
-			if (lstgrp_noio == NULL)
+			if (!lstgrp_noio)
 				ios[0]->head = grp;
 			else
 				WRITE_ONCE(lstgrp_noio->next, grp);
@@ -1235,13 +1235,13 @@ static bool z_erofs_vle_submit_all(struct super_block *sb,
 #endif
 	} while (owned_head != Z_EROFS_VLE_WORKGRP_TAIL);
 
-	if (bio != NULL)
+	if (bio)
 		__submit_bio(bio, REQ_OP_READ, 0);
 
 #ifndef EROFS_FS_HAS_MANAGED_CACHE
 	BUG_ON(!nr_bios);
 #else
-	if (lstgrp_noio != NULL)
+	if (lstgrp_noio)
 		WRITE_ONCE(lstgrp_noio->next, Z_EROFS_VLE_WORKGRP_TAIL_CLOSED);
 
 	if (!force_fg && !nr_bios) {
@@ -1300,7 +1300,7 @@ static int z_erofs_vle_normalaccess_readpage(struct file *file,
 
 	z_erofs_submit_and_unzip(&f, &pagepool, true);
 out:
-	if (f.m_iter.mpage != NULL)
+	if (f.m_iter.mpage)
 		put_page(f.m_iter.mpage);
 
 	/* clean up the remaining free pages */
@@ -1344,7 +1344,7 @@ static int z_erofs_vle_normalaccess_readpages(struct file *filp,
 		head = page;
 	}
 
-	while (head != NULL) {
+	while (head) {
 		struct page *page = head;
 		int err;
 
@@ -1366,7 +1366,7 @@ static int z_erofs_vle_normalaccess_readpages(struct file *filp,
 
 	z_erofs_submit_and_unzip(&f, &pagepool, sync);
 
-	if (f.m_iter.mpage != NULL)
+	if (f.m_iter.mpage)
 		put_page(f.m_iter.mpage);
 
 	/* clean up the remaining free pages */
@@ -1561,7 +1561,7 @@ int z_erofs_map_blocks_iter(struct inode *inode,
 	mblk = vle_extent_blkaddr(inode, lcn);
 
 	if (!mpage || mpage->index != mblk) {
-		if (mpage != NULL)
+		if (mpage)
 			put_page(mpage);
 
 		mpage = erofs_get_meta_page(ctx.sb, mblk, false);
-- 
2.7.4

Re: [PATCH 1/3] staging: erofs: unzip_vle.c: Replace comparison to NULL.

[Greg Kroah-Hartman]

On Mon, Nov 12, 2018 at 09:43:57PM +0100, Cristian Sicilia wrote:
> Replace equal to NULL with logic unary operator,
> and removing not equal to NULL comparison.
> 
> Signed-off-by: Cristian Sicilia <sicilia.cristian@gmail.com>
> ---
>  drivers/staging/erofs/unzip_vle.c | 86 +++++++++++++++++++--------------------
>  1 file changed, 43 insertions(+), 43 deletions(-)
> 
> diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c
> index 79d3ba6..1ffeeaa 100644
> --- a/drivers/staging/erofs/unzip_vle.c
> +++ b/drivers/staging/erofs/unzip_vle.c
> @@ -20,8 +20,8 @@ static struct kmem_cache *z_erofs_workgroup_cachep __read_mostly;
>  
>  void z_erofs_exit_zip_subsystem(void)
>  {
> -	BUG_ON(z_erofs_workqueue == NULL);
> -	BUG_ON(z_erofs_workgroup_cachep == NULL);
> +	BUG_ON(!z_erofs_workqueue);
> +	BUG_ON(!z_erofs_workgroup_cachep);

Long-term, all of these BUG_ON need to be removed as they imply that the
developer has no idea what went wrong and can not recover.  For
something like this, we "know" these will be fine and odds are they can
just be removed entirely.

>  
>  	destroy_workqueue(z_erofs_workqueue);
>  	kmem_cache_destroy(z_erofs_workgroup_cachep);
> @@ -39,7 +39,7 @@ static inline int init_unzip_workqueue(void)
>  		WQ_UNBOUND | WQ_HIGHPRI | WQ_CPU_INTENSIVE,
>  		onlinecpus + onlinecpus / 4);
>  
> -	return z_erofs_workqueue != NULL ? 0 : -ENOMEM;
> +	return z_erofs_workqueue ? 0 : -ENOMEM;

I hate ?: notation that is not in a function parameter, any way you can
just change this to:
	if (z_erofs_workqueue)
		return 0;
	return -ENOMEM;

Christian, this isn't your fault at all, I'm not rejecting this patch,
just providing hints on what else you can do here :)

thanks,

greg k-h

Re: [PATCH 1/3] staging: erofs: unzip_vle.c: Replace comparison to NULL.

[Greg Kroah-Hartman]

On Tue, Nov 13, 2018 at 12:31:58AM +0100, Cristian Sicilia wrote:
> On Mon, Nov 12, 2018 at 11:46 PM Greg Kroah-Hartman <
> gregkh@linuxfoundation.org> wrote:
> 
> > On Mon, Nov 12, 2018 at 09:43:57PM +0100, Cristian Sicilia wrote:
> > > Replace equal to NULL with logic unary operator,
> > > and removing not equal to NULL comparison.
> > >
> > > Signed-off-by: Cristian Sicilia <sicilia.cristian@gmail.com>
> > > ---
> > >  drivers/staging/erofs/unzip_vle.c | 86
> > +++++++++++++++++++--------------------
> > >  1 file changed, 43 insertions(+), 43 deletions(-)
> > >
> > > diff --git a/drivers/staging/erofs/unzip_vle.c
> > b/drivers/staging/erofs/unzip_vle.c
> > > index 79d3ba6..1ffeeaa 100644
> > > --- a/drivers/staging/erofs/unzip_vle.c
> > > +++ b/drivers/staging/erofs/unzip_vle.c
> > > @@ -20,8 +20,8 @@ static struct kmem_cache *z_erofs_workgroup_cachep
> > __read_mostly;
> > >
> > >  void z_erofs_exit_zip_subsystem(void)
> > >  {
> > > -     BUG_ON(z_erofs_workqueue == NULL);
> > > -     BUG_ON(z_erofs_workgroup_cachep == NULL);
> > > +     BUG_ON(!z_erofs_workqueue);
> > > +     BUG_ON(!z_erofs_workgroup_cachep);
> >
> > Long-term, all of these BUG_ON need to be removed as they imply that the
> > developer has no idea what went wrong and can not recover.  For
> > something like this, we "know" these will be fine and odds are they can
> > just be removed entirely.
> >
> >
> Right, I'm watching how replace the BUG_ON with WARN_ON and check who call
> this functions

No, why would WARN_ON be any better?  Systems run with "panic on warn"
enabled and this would cause the machine to reboot.  Why are these
things even being checked in the first place if they are impossible to
hit?

If they really are impossible, remove the check.  If they are not, then
properly handle the logic if they are true.

Linus said the other day something like "programmers who use BUG_ON()
don't know what their code does", and I agree.  They are a crutch that
we need to fix up in the whole kernel, not just staging.

> > >       destroy_workqueue(z_erofs_workqueue);
> > >       kmem_cache_destroy(z_erofs_workgroup_cachep);
> > > @@ -39,7 +39,7 @@ static inline int init_unzip_workqueue(void)
> > >               WQ_UNBOUND | WQ_HIGHPRI | WQ_CPU_INTENSIVE,
> > >               onlinecpus + onlinecpus / 4);
> > >
> > > -     return z_erofs_workqueue != NULL ? 0 : -ENOMEM;
> > > +     return z_erofs_workqueue ? 0 : -ENOMEM;
> >
> > I hate ?: notation that is not in a function parameter, any way you can
> > just change this to:
> >         if (z_erofs_workqueue)
> >                 return 0;
> >         return -ENOMEM;
> >
> >
> I will replace the ?: too
> 
> 
> > Christian, this isn't your fault at all, I'm not rejecting this patch,
> > just providing hints on what else you can do here :)
> >
> 
> 
> but (if I well understand) I will send a different patch for both fix,
> right?

Yes, nothing wrong with this one that I could see.  I'll let the erofs
maintainers review it first before applying it in a few days to my tree.

thanks,

greg k-h

Re: [PATCH 1/3] staging: erofs: unzip_vle.c: Replace comparison to NULL.

[Gao Xiang]

Hi Greg,

On 2018/11/13 7:46, Greg Kroah-Hartman wrote:
> On Tue, Nov 13, 2018 at 12:31:58AM +0100, Cristian Sicilia wrote:
>> On Mon, Nov 12, 2018 at 11:46 PM Greg Kroah-Hartman <
>> gregkh@linuxfoundation.org> wrote:
>>
>>> On Mon, Nov 12, 2018 at 09:43:57PM +0100, Cristian Sicilia wrote:
>>>> Replace equal to NULL with logic unary operator,
>>>> and removing not equal to NULL comparison.
>>>>
>>>> Signed-off-by: Cristian Sicilia <sicilia.cristian@gmail.com>
>>>> ---
>>>>  drivers/staging/erofs/unzip_vle.c | 86
>>> +++++++++++++++++++--------------------
>>>>  1 file changed, 43 insertions(+), 43 deletions(-)
>>>>
>>>> diff --git a/drivers/staging/erofs/unzip_vle.c
>>> b/drivers/staging/erofs/unzip_vle.c
>>>> index 79d3ba6..1ffeeaa 100644
>>>> --- a/drivers/staging/erofs/unzip_vle.c
>>>> +++ b/drivers/staging/erofs/unzip_vle.c
>>>> @@ -20,8 +20,8 @@ static struct kmem_cache *z_erofs_workgroup_cachep
>>> __read_mostly;
>>>>
>>>>  void z_erofs_exit_zip_subsystem(void)
>>>>  {
>>>> -     BUG_ON(z_erofs_workqueue == NULL);
>>>> -     BUG_ON(z_erofs_workgroup_cachep == NULL);
>>>> +     BUG_ON(!z_erofs_workqueue);
>>>> +     BUG_ON(!z_erofs_workgroup_cachep);
>>>
>>> Long-term, all of these BUG_ON need to be removed as they imply that the
>>> developer has no idea what went wrong and can not recover.  For
>>> something like this, we "know" these will be fine and odds are they can
>>> just be removed entirely.
>>>
>>>
>> Right, I'm watching how replace the BUG_ON with WARN_ON and check who call
>> this functions
> 
> No, why would WARN_ON be any better?  Systems run with "panic on warn"
> enabled and this would cause the machine to reboot.  Why are these
> things even being checked in the first place if they are impossible to
> hit?
> 
> If they really are impossible, remove the check.  If they are not, then
> properly handle the logic if they are true.

I will remove the above BUG_ON()s since it looks redundant.

> 
> Linus said the other day something like "programmers who use BUG_ON()
> don't know what their code does", and I agree.  They are a crutch that
> we need to fix up in the whole kernel, not just staging.

I agree the phrase "programmers who use BUG_ON() don't know what their code does".
and some potential race I think it cannot happen in principle, but I also want to check them
on runtime via beta users, that should be avoided case by case.

erofs has another CONFIG_EROFS_FS_DEBUG switch to make some on-disk
assertions aggressively in development/debug mode, if CONFIG_EROFS_FS_DEBUG is on,
DBG_BUGON will be a BUG_ON; otherwise, it also has error handling paths to deal with them properly.
I have no idea whether I'm doing the right thing or not... such switch can also be found in f2fs called "F2FS_CHECK_FS".

config F2FS_CHECK_FS
	bool "F2FS consistency checking feature"
	depends on F2FS_FS
	help
	  Enables BUG_ONs which check the filesystem consistency in runtime.

	  If you want to improve the performance, say N.

Could you kindly give me some suggestions? Thanks..


> 
>>>>       destroy_workqueue(z_erofs_workqueue);
>>>>       kmem_cache_destroy(z_erofs_workgroup_cachep);
>>>> @@ -39,7 +39,7 @@ static inline int init_unzip_workqueue(void)
>>>>               WQ_UNBOUND | WQ_HIGHPRI | WQ_CPU_INTENSIVE,
>>>>               onlinecpus + onlinecpus / 4);
>>>>
>>>> -     return z_erofs_workqueue != NULL ? 0 : -ENOMEM;
>>>> +     return z_erofs_workqueue ? 0 : -ENOMEM;
>>>
>>> I hate ?: notation that is not in a function parameter, any way you can
>>> just change this to:
>>>         if (z_erofs_workqueue)
>>>                 return 0;
>>>         return -ENOMEM;

OK, I will avoid these unnecessary ?: notations.

>>>
>>>
>> I will replace the ?: too
>>
>>
>>> Christian, this isn't your fault at all, I'm not rejecting this patch,
>>> just providing hints on what else you can do here :)
>>>
>>
>>
>> but (if I well understand) I will send a different patch for both fix,
>> right?
> 
> Yes, nothing wrong with this one that I could see.  I'll let the erofs
> maintainers review it first before applying it in a few days to my tree
These patches look good to me, and I will avoid this BUG_ON case by case as I promised to Al
before moving out the staging tree.

Thanks,
Gao Xiang


> 
> thanks,
> 
> greg k-h
> 

Re: [PATCH 1/3] staging: erofs: unzip_vle.c: Replace comparison to NULL.

[Gao Xiang]

Hi Cristian,

On 2018/11/13 4:43, Cristian Sicilia wrote:
> Replace equal to NULL with logic unary operator,
> and removing not equal to NULL comparison.
> 
> Signed-off-by: Cristian Sicilia <sicilia.cristian@gmail.com>

Indeed, I have several pending changes for this file...
But these coding style fixes looks good to me. I will rebase them on your work...

Reviewed-by: Gao Xiang <gaoxiang25@huawei.com>

Thanks,
Gao Xiang

Re: [PATCH 1/3] staging: erofs: unzip_vle.c: Replace comparison to NULL.

[Chao Yu]

On 2018/11/13 4:43, Cristian Sicilia wrote:
> Replace equal to NULL with logic unary operator,
> and removing not equal to NULL comparison.
> 
> Signed-off-by: Cristian Sicilia <sicilia.cristian@gmail.com>

Reviewed-by: Chao Yu <yuchao0@huawei.com>

Thanks,

[PATCH 2/3] staging: erofs: unzip_vle.c: Constant in comparison on right side

[Cristian Sicilia]

Comparisons should place the constant
on the right side of the test.

Signed-off-by: Cristian Sicilia <sicilia.cristian@gmail.com>
---
 drivers/staging/erofs/unzip_vle.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c
index 1ffeeaa..35add4e 100644
--- a/drivers/staging/erofs/unzip_vle.c
+++ b/drivers/staging/erofs/unzip_vle.c
@@ -250,8 +250,8 @@ static inline bool try_to_claim_workgroup(
 retry:
 	if (grp->next == Z_EROFS_VLE_WORKGRP_NIL) {
 		/* type 1, nil workgroup */
-		if (Z_EROFS_VLE_WORKGRP_NIL != cmpxchg(&grp->next,
-			Z_EROFS_VLE_WORKGRP_NIL, *owned_head))
+		if (cmpxchg(&grp->next, Z_EROFS_VLE_WORKGRP_NIL,
+			    *owned_head) != Z_EROFS_VLE_WORKGRP_NIL)
 			goto retry;
 
 		*owned_head = grp;
@@ -262,8 +262,8 @@ static inline bool try_to_claim_workgroup(
 		 * be careful that its submission itself is governed
 		 * by the original owned chain.
 		 */
-		if (Z_EROFS_VLE_WORKGRP_TAIL != cmpxchg(&grp->next,
-			Z_EROFS_VLE_WORKGRP_TAIL, *owned_head))
+		if (cmpxchg(&grp->next, Z_EROFS_VLE_WORKGRP_TAIL,
+			    *owned_head) != Z_EROFS_VLE_WORKGRP_TAIL)
 			goto retry;
 
 		*owned_head = Z_EROFS_VLE_WORKGRP_TAIL;
-- 
2.7.4

Re: [PATCH 2/3] staging: erofs: unzip_vle.c: Constant in comparison on right side

[Gao Xiang]

On 2018/11/13 4:43, Cristian Sicilia wrote:
> Comparisons should place the constant
> on the right side of the test.
> 
> Signed-off-by: Cristian Sicilia <sicilia.cristian@gmail.com>

Reviewed-by: Gao Xiang <gaoxiang25@huawei.com>

Thanks,
Gao Xiang

> ---
>  drivers/staging/erofs/unzip_vle.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c
> index 1ffeeaa..35add4e 100644
> --- a/drivers/staging/erofs/unzip_vle.c
> +++ b/drivers/staging/erofs/unzip_vle.c
> @@ -250,8 +250,8 @@ static inline bool try_to_claim_workgroup(
>  retry:
>  	if (grp->next == Z_EROFS_VLE_WORKGRP_NIL) {
>  		/* type 1, nil workgroup */
> -		if (Z_EROFS_VLE_WORKGRP_NIL != cmpxchg(&grp->next,
> -			Z_EROFS_VLE_WORKGRP_NIL, *owned_head))
> +		if (cmpxchg(&grp->next, Z_EROFS_VLE_WORKGRP_NIL,
> +			    *owned_head) != Z_EROFS_VLE_WORKGRP_NIL)
>  			goto retry;
>  
>  		*owned_head = grp;
> @@ -262,8 +262,8 @@ static inline bool try_to_claim_workgroup(
>  		 * be careful that its submission itself is governed
>  		 * by the original owned chain.
>  		 */
> -		if (Z_EROFS_VLE_WORKGRP_TAIL != cmpxchg(&grp->next,
> -			Z_EROFS_VLE_WORKGRP_TAIL, *owned_head))
> +		if (cmpxchg(&grp->next, Z_EROFS_VLE_WORKGRP_TAIL,
> +			    *owned_head) != Z_EROFS_VLE_WORKGRP_TAIL)
>  			goto retry;
>  
>  		*owned_head = Z_EROFS_VLE_WORKGRP_TAIL;
> 

Re: [PATCH 2/3] staging: erofs: unzip_vle.c: Constant in comparison on right side

[Chao Yu]

On 2018/11/13 4:43, Cristian Sicilia wrote:
> Comparisons should place the constant
> on the right side of the test.
> 
> Signed-off-by: Cristian Sicilia <sicilia.cristian@gmail.com>

Reviewed-by: Chao Yu <yuchao0@huawei.com>

Thanks,

[PATCH 3/3] staging: erofs: unzip_vle.c: Align parameter to the parentesis

[Cristian Sicilia]

Align parameters to the opened parentesis.

Signed-off-by: Cristian Sicilia <sicilia.cristian@gmail.com>
---
 drivers/staging/erofs/unzip_vle.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c
index 35add4e..6a283f6 100644
--- a/drivers/staging/erofs/unzip_vle.c
+++ b/drivers/staging/erofs/unzip_vle.c
@@ -35,9 +35,10 @@ static inline int init_unzip_workqueue(void)
 	 * we don't need too many threads, limiting threads
 	 * could improve scheduling performance.
 	 */
-	z_erofs_workqueue = alloc_workqueue("erofs_unzipd",
-		WQ_UNBOUND | WQ_HIGHPRI | WQ_CPU_INTENSIVE,
-		onlinecpus + onlinecpus / 4);
+	z_erofs_workqueue =
+		alloc_workqueue("erofs_unzipd",
+				WQ_UNBOUND | WQ_HIGHPRI | WQ_CPU_INTENSIVE,
+				onlinecpus + onlinecpus / 4);
 
 	return z_erofs_workqueue ? 0 : -ENOMEM;
 }
@@ -46,8 +47,8 @@ int __init z_erofs_init_zip_subsystem(void)
 {
 	z_erofs_workgroup_cachep =
 		kmem_cache_create("erofs_compress",
-		Z_EROFS_WORKGROUP_SIZE, 0,
-		SLAB_RECLAIM_ACCOUNT, NULL);
+				  Z_EROFS_WORKGROUP_SIZE, 0,
+				  SLAB_RECLAIM_ACCOUNT, NULL);
 
 	if (z_erofs_workgroup_cachep) {
 		if (!init_unzip_workqueue())
-- 
2.7.4

Re: [PATCH 3/3] staging: erofs: unzip_vle.c: Align parameter to the parentesis

[Gao Xiang]

On 2018/11/13 4:43, Cristian Sicilia wrote:
> Align parameters to the opened parentesis.
> 
> Signed-off-by: Cristian Sicilia <sicilia.cristian@gmail.com>

Reviewed-by: Gao Xiang <gaoxiang25@huawei.com>

Thanks,
Gao Xiang

> ---
>  drivers/staging/erofs/unzip_vle.c | 11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c
> index 35add4e..6a283f6 100644
> --- a/drivers/staging/erofs/unzip_vle.c
> +++ b/drivers/staging/erofs/unzip_vle.c
> @@ -35,9 +35,10 @@ static inline int init_unzip_workqueue(void)
>  	 * we don't need too many threads, limiting threads
>  	 * could improve scheduling performance.
>  	 */
> -	z_erofs_workqueue = alloc_workqueue("erofs_unzipd",
> -		WQ_UNBOUND | WQ_HIGHPRI | WQ_CPU_INTENSIVE,
> -		onlinecpus + onlinecpus / 4);
> +	z_erofs_workqueue =
> +		alloc_workqueue("erofs_unzipd",
> +				WQ_UNBOUND | WQ_HIGHPRI | WQ_CPU_INTENSIVE,
> +				onlinecpus + onlinecpus / 4);
>  
>  	return z_erofs_workqueue ? 0 : -ENOMEM;
>  }
> @@ -46,8 +47,8 @@ int __init z_erofs_init_zip_subsystem(void)
>  {
>  	z_erofs_workgroup_cachep =
>  		kmem_cache_create("erofs_compress",
> -		Z_EROFS_WORKGROUP_SIZE, 0,
> -		SLAB_RECLAIM_ACCOUNT, NULL);
> +				  Z_EROFS_WORKGROUP_SIZE, 0,
> +				  SLAB_RECLAIM_ACCOUNT, NULL);
>  
>  	if (z_erofs_workgroup_cachep) {
>  		if (!init_unzip_workqueue())
> 

Re: [PATCH 3/3] staging: erofs: unzip_vle.c: Align parameter to the parentesis

[Chao Yu]

On 2018/11/13 4:43, Cristian Sicilia wrote:
> Align parameters to the opened parentesis.
> 
> Signed-off-by: Cristian Sicilia <sicilia.cristian@gmail.com>

Reviewed-by: Chao Yu <yuchao0@huawei.com>

Thanks,