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* [PATCH v2 0/2] kill add_to_page_cache_locked()
@ 2020-10-21 19:57 Kent Overstreet
  2020-10-21 19:57 ` [PATCH v2 1/2] cifs: convert to add_to_page_cache() Kent Overstreet
  2020-10-21 19:57 ` [PATCH v2 2/2] fs: kill add_to_page_cache_locked() Kent Overstreet
  0 siblings, 2 replies; 6+ messages in thread
From: Kent Overstreet @ 2020-10-21 19:57 UTC (permalink / raw)
  To: linux-kernel, linux-fsdevel, akpm, sfrench, linux-cifs; +Cc: Kent Overstreet

since v1
 - kill a faulty assertion found by kernel test robot
 - drop an unneeded line break

Andrew, can this go through your tree?

Kent Overstreet (2):
  cifs: convert to add_to_page_cache()
  fs: kill add_to_page_cache_locked()

 fs/cifs/file.c          | 20 +++----------
 include/linux/pagemap.h | 20 ++-----------
 mm/filemap.c            | 64 ++++++++++++++++++++---------------------
 3 files changed, 37 insertions(+), 67 deletions(-)

-- 
2.28.0


^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH v2 1/2] cifs: convert to add_to_page_cache()
  2020-10-21 19:57 [PATCH v2 0/2] kill add_to_page_cache_locked() Kent Overstreet
@ 2020-10-21 19:57 ` Kent Overstreet
  2020-10-22  8:36   ` Steve French
  2020-11-11  0:52   ` Matthew Wilcox
  2020-10-21 19:57 ` [PATCH v2 2/2] fs: kill add_to_page_cache_locked() Kent Overstreet
  1 sibling, 2 replies; 6+ messages in thread
From: Kent Overstreet @ 2020-10-21 19:57 UTC (permalink / raw)
  To: linux-kernel, linux-fsdevel, akpm, sfrench, linux-cifs; +Cc: Kent Overstreet

This is just open coding add_to_page_cache(), and the next patch will
delete add_to_page_cache_locked().

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
---
 fs/cifs/file.c | 20 ++++----------------
 1 file changed, 4 insertions(+), 16 deletions(-)

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index be46fab4c9..b3ee790532 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -4296,20 +4296,11 @@ readpages_get_pages(struct address_space *mapping, struct list_head *page_list,
 
 	page = lru_to_page(page_list);
 
-	/*
-	 * Lock the page and put it in the cache. Since no one else
-	 * should have access to this page, we're safe to simply set
-	 * PG_locked without checking it first.
-	 */
-	__SetPageLocked(page);
-	rc = add_to_page_cache_locked(page, mapping,
-				      page->index, gfp);
+	rc = add_to_page_cache(page, mapping, page->index, gfp);
 
 	/* give up if we can't stick it in the cache */
-	if (rc) {
-		__ClearPageLocked(page);
+	if (rc)
 		return rc;
-	}
 
 	/* move first page to the tmplist */
 	*offset = (loff_t)page->index << PAGE_SHIFT;
@@ -4328,12 +4319,9 @@ readpages_get_pages(struct address_space *mapping, struct list_head *page_list,
 		if (*bytes + PAGE_SIZE > rsize)
 			break;
 
-		__SetPageLocked(page);
-		rc = add_to_page_cache_locked(page, mapping, page->index, gfp);
-		if (rc) {
-			__ClearPageLocked(page);
+		rc = add_to_page_cache(page, mapping, page->index, gfp);
+		if (rc)
 			break;
-		}
 		list_move_tail(&page->lru, tmplist);
 		(*bytes) += PAGE_SIZE;
 		expected_index++;
-- 
2.28.0


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH v2 2/2] fs: kill add_to_page_cache_locked()
  2020-10-21 19:57 [PATCH v2 0/2] kill add_to_page_cache_locked() Kent Overstreet
  2020-10-21 19:57 ` [PATCH v2 1/2] cifs: convert to add_to_page_cache() Kent Overstreet
@ 2020-10-21 19:57 ` Kent Overstreet
  2020-10-21 20:51   ` Matthew Wilcox
  1 sibling, 1 reply; 6+ messages in thread
From: Kent Overstreet @ 2020-10-21 19:57 UTC (permalink / raw)
  To: linux-kernel, linux-fsdevel, akpm, sfrench, linux-cifs; +Cc: Kent Overstreet

No longer has any users, so remove it.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
---
 include/linux/pagemap.h | 20 ++-----------
 mm/filemap.c            | 64 ++++++++++++++++++++---------------------
 2 files changed, 33 insertions(+), 51 deletions(-)

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 434c9c34ae..aceaebfaab 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -689,8 +689,8 @@ static inline int fault_in_pages_readable(const char __user *uaddr, int size)
 	return 0;
 }
 
-int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
-				pgoff_t index, gfp_t gfp_mask);
+int add_to_page_cache(struct page *page, struct address_space *mapping,
+		      pgoff_t index, gfp_t gfp_mask);
 int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
 				pgoff_t index, gfp_t gfp_mask);
 extern void delete_from_page_cache(struct page *page);
@@ -710,22 +710,6 @@ void page_cache_readahead_unbounded(struct address_space *, struct file *,
 		pgoff_t index, unsigned long nr_to_read,
 		unsigned long lookahead_count);
 
-/*
- * Like add_to_page_cache_locked, but used to add newly allocated pages:
- * the page is new, so we can just run __SetPageLocked() against it.
- */
-static inline int add_to_page_cache(struct page *page,
-		struct address_space *mapping, pgoff_t offset, gfp_t gfp_mask)
-{
-	int error;
-
-	__SetPageLocked(page);
-	error = add_to_page_cache_locked(page, mapping, offset, gfp_mask);
-	if (unlikely(error))
-		__ClearPageLocked(page);
-	return error;
-}
-
 /**
  * struct readahead_control - Describes a readahead request.
  *
diff --git a/mm/filemap.c b/mm/filemap.c
index bb71334fdd..b92ca48b90 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -827,20 +827,20 @@ int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask)
 }
 EXPORT_SYMBOL_GPL(replace_page_cache_page);
 
-static int __add_to_page_cache_locked(struct page *page,
-				      struct address_space *mapping,
-				      pgoff_t offset, gfp_t gfp_mask,
-				      void **shadowp)
+static int __add_to_page_cache(struct page *page,
+			       struct address_space *mapping,
+			       pgoff_t offset, gfp_t gfp_mask,
+			       void **shadowp)
 {
 	XA_STATE(xas, &mapping->i_pages, offset);
 	int huge = PageHuge(page);
 	int error;
 	void *old;
 
-	VM_BUG_ON_PAGE(!PageLocked(page), page);
 	VM_BUG_ON_PAGE(PageSwapBacked(page), page);
 	mapping_set_update(&xas, mapping);
 
+	__SetPageLocked(page);
 	get_page(page);
 	page->mapping = mapping;
 	page->index = offset;
@@ -885,29 +885,31 @@ static int __add_to_page_cache_locked(struct page *page,
 	page->mapping = NULL;
 	/* Leave page->index set: truncation relies upon it */
 	put_page(page);
+	__ClearPageLocked(page);
 	return error;
 }
-ALLOW_ERROR_INJECTION(__add_to_page_cache_locked, ERRNO);
+ALLOW_ERROR_INJECTION(__add_to_page_cache, ERRNO);
 
 /**
- * add_to_page_cache_locked - add a locked page to the pagecache
+ * add_to_page_cache - add a newly allocated page to the pagecache
  * @page:	page to add
  * @mapping:	the page's address_space
  * @offset:	page index
  * @gfp_mask:	page allocation mode
  *
- * This function is used to add a page to the pagecache. It must be locked.
- * This function does not add the page to the LRU.  The caller must do that.
+ * This function is used to add a page to the pagecache. It must be newly
+ * allocated.  This function does not add the page to the LRU.  The caller must
+ * do that.
  *
  * Return: %0 on success, negative error code otherwise.
  */
-int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
-		pgoff_t offset, gfp_t gfp_mask)
+int add_to_page_cache(struct page *page, struct address_space *mapping,
+		      pgoff_t offset, gfp_t gfp_mask)
 {
-	return __add_to_page_cache_locked(page, mapping, offset,
-					  gfp_mask, NULL);
+	return __add_to_page_cache(page, mapping, offset, gfp_mask, NULL);
 }
-EXPORT_SYMBOL(add_to_page_cache_locked);
+EXPORT_SYMBOL(add_to_page_cache);
+ALLOW_ERROR_INJECTION(add_to_page_cache, ERRNO);
 
 int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
 				pgoff_t offset, gfp_t gfp_mask)
@@ -915,26 +917,22 @@ int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
 	void *shadow = NULL;
 	int ret;
 
-	__SetPageLocked(page);
-	ret = __add_to_page_cache_locked(page, mapping, offset,
-					 gfp_mask, &shadow);
+	ret = __add_to_page_cache(page, mapping, offset, gfp_mask, &shadow);
 	if (unlikely(ret))
-		__ClearPageLocked(page);
-	else {
-		/*
-		 * The page might have been evicted from cache only
-		 * recently, in which case it should be activated like
-		 * any other repeatedly accessed page.
-		 * The exception is pages getting rewritten; evicting other
-		 * data from the working set, only to cache data that will
-		 * get overwritten with something else, is a waste of memory.
-		 */
-		WARN_ON_ONCE(PageActive(page));
-		if (!(gfp_mask & __GFP_WRITE) && shadow)
-			workingset_refault(page, shadow);
-		lru_cache_add(page);
-	}
-	return ret;
+		return ret;
+
+	/*
+	 * The page might have been evicted from cache only recently, in which
+	 * case it should be activated like any other repeatedly accessed page.
+	 * The exception is pages getting rewritten; evicting other data from
+	 * the working set, only to cache data that will get overwritten with
+	 * something else, is a waste of memory.
+	 */
+	WARN_ON_ONCE(PageActive(page));
+	if (!(gfp_mask & __GFP_WRITE) && shadow)
+		workingset_refault(page, shadow);
+	lru_cache_add(page);
+	return 0;
 }
 EXPORT_SYMBOL_GPL(add_to_page_cache_lru);
 
-- 
2.28.0


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH v2 2/2] fs: kill add_to_page_cache_locked()
  2020-10-21 19:57 ` [PATCH v2 2/2] fs: kill add_to_page_cache_locked() Kent Overstreet
@ 2020-10-21 20:51   ` Matthew Wilcox
  0 siblings, 0 replies; 6+ messages in thread
From: Matthew Wilcox @ 2020-10-21 20:51 UTC (permalink / raw)
  To: Kent Overstreet; +Cc: linux-kernel, linux-fsdevel, akpm, sfrench, linux-cifs

On Wed, Oct 21, 2020 at 03:57:45PM -0400, Kent Overstreet wrote:
>  }
> -ALLOW_ERROR_INJECTION(__add_to_page_cache_locked, ERRNO);
> +ALLOW_ERROR_INJECTION(__add_to_page_cache, ERRNO);
[..]
> +int add_to_page_cache(struct page *page, struct address_space *mapping,
> +		      pgoff_t offset, gfp_t gfp_mask)
>  {
> -	return __add_to_page_cache_locked(page, mapping, offset,
> -					  gfp_mask, NULL);
> +	return __add_to_page_cache(page, mapping, offset, gfp_mask, NULL);
>  }
> -EXPORT_SYMBOL(add_to_page_cache_locked);
> +EXPORT_SYMBOL(add_to_page_cache);
> +ALLOW_ERROR_INJECTION(add_to_page_cache, ERRNO);

I don't think you need this second one since __add_to_page_cache can be
used for the same purpose.

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v2 1/2] cifs: convert to add_to_page_cache()
  2020-10-21 19:57 ` [PATCH v2 1/2] cifs: convert to add_to_page_cache() Kent Overstreet
@ 2020-10-22  8:36   ` Steve French
  2020-11-11  0:52   ` Matthew Wilcox
  1 sibling, 0 replies; 6+ messages in thread
From: Steve French @ 2020-10-22  8:36 UTC (permalink / raw)
  To: Kent Overstreet; +Cc: LKML, linux-fsdevel, Andrew Morton, Steve French, CIFS

you can add my reviewed-by if you would like

On Thu, Oct 22, 2020 at 1:48 AM Kent Overstreet
<kent.overstreet@gmail.com> wrote:
>
> This is just open coding add_to_page_cache(), and the next patch will
> delete add_to_page_cache_locked().
>
> Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
> ---
>  fs/cifs/file.c | 20 ++++----------------
>  1 file changed, 4 insertions(+), 16 deletions(-)
>
> diff --git a/fs/cifs/file.c b/fs/cifs/file.c
> index be46fab4c9..b3ee790532 100644
> --- a/fs/cifs/file.c
> +++ b/fs/cifs/file.c
> @@ -4296,20 +4296,11 @@ readpages_get_pages(struct address_space *mapping, struct list_head *page_list,
>
>         page = lru_to_page(page_list);
>
> -       /*
> -        * Lock the page and put it in the cache. Since no one else
> -        * should have access to this page, we're safe to simply set
> -        * PG_locked without checking it first.
> -        */
> -       __SetPageLocked(page);
> -       rc = add_to_page_cache_locked(page, mapping,
> -                                     page->index, gfp);
> +       rc = add_to_page_cache(page, mapping, page->index, gfp);
>
>         /* give up if we can't stick it in the cache */
> -       if (rc) {
> -               __ClearPageLocked(page);
> +       if (rc)
>                 return rc;
> -       }
>
>         /* move first page to the tmplist */
>         *offset = (loff_t)page->index << PAGE_SHIFT;
> @@ -4328,12 +4319,9 @@ readpages_get_pages(struct address_space *mapping, struct list_head *page_list,
>                 if (*bytes + PAGE_SIZE > rsize)
>                         break;
>
> -               __SetPageLocked(page);
> -               rc = add_to_page_cache_locked(page, mapping, page->index, gfp);
> -               if (rc) {
> -                       __ClearPageLocked(page);
> +               rc = add_to_page_cache(page, mapping, page->index, gfp);
> +               if (rc)
>                         break;
> -               }
>                 list_move_tail(&page->lru, tmplist);
>                 (*bytes) += PAGE_SIZE;
>                 expected_index++;
> --
> 2.28.0
>


-- 
Thanks,

Steve

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v2 1/2] cifs: convert to add_to_page_cache()
  2020-10-21 19:57 ` [PATCH v2 1/2] cifs: convert to add_to_page_cache() Kent Overstreet
  2020-10-22  8:36   ` Steve French
@ 2020-11-11  0:52   ` Matthew Wilcox
  1 sibling, 0 replies; 6+ messages in thread
From: Matthew Wilcox @ 2020-11-11  0:52 UTC (permalink / raw)
  To: Kent Overstreet; +Cc: linux-kernel, linux-fsdevel, akpm, sfrench, linux-cifs

On Wed, Oct 21, 2020 at 03:57:44PM -0400, Kent Overstreet wrote:
> This is just open coding add_to_page_cache(), and the next patch will
> delete add_to_page_cache_locked().
> 
> Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2020-11-11  0:53 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-10-21 19:57 [PATCH v2 0/2] kill add_to_page_cache_locked() Kent Overstreet
2020-10-21 19:57 ` [PATCH v2 1/2] cifs: convert to add_to_page_cache() Kent Overstreet
2020-10-22  8:36   ` Steve French
2020-11-11  0:52   ` Matthew Wilcox
2020-10-21 19:57 ` [PATCH v2 2/2] fs: kill add_to_page_cache_locked() Kent Overstreet
2020-10-21 20:51   ` Matthew Wilcox

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