All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
To: akpm@linux-foundation.org
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>,
	linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org, Vlastimil Babka <vbabka@suse.cz>,
	William Kucharski <william.kucharski@oracle.com>,
	Christoph Hellwig <hch@lst.de>
Subject: [PATCH v11 32/33] fs/netfs: Add folio fscache functions
Date: Mon, 14 Jun 2021 21:14:34 +0100	[thread overview]
Message-ID: <20210614201435.1379188-33-willy@infradead.org> (raw)
In-Reply-To: <20210614201435.1379188-1-willy@infradead.org>

Match the page writeback functions by adding
folio_start_fscache(), folio_end_fscache(), folio_wait_fscache() and
folio_wait_fscache_killable().  Remove set_page_private_2().  Also rewrite
the kernel-doc to describe when to use the function rather than what the
function does, and include the kernel-doc in the appropriate rst file.
Saves 31 bytes of text in netfs_rreq_unlock() due to set_page_fscache()
calling page_folio() once instead of three times.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 Documentation/filesystems/netfs_library.rst |  2 +
 include/linux/netfs.h                       | 75 +++++++++++++--------
 include/linux/pagemap.h                     | 16 -----
 3 files changed, 50 insertions(+), 43 deletions(-)

diff --git a/Documentation/filesystems/netfs_library.rst b/Documentation/filesystems/netfs_library.rst
index 57a641847818..bb68d39f03b7 100644
--- a/Documentation/filesystems/netfs_library.rst
+++ b/Documentation/filesystems/netfs_library.rst
@@ -524,3 +524,5 @@ Note that these methods are passed a pointer to the cache resource structure,
 not the read request structure as they could be used in other situations where
 there isn't a read request structure as well, such as writing dirty data to the
 cache.
+
+.. kernel-doc:: include/linux/netfs.h
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index fad8c6209edd..b0bbd343fc98 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -22,6 +22,7 @@
  * Overload PG_private_2 to give us PG_fscache - this is used to indicate that
  * a page is currently backed by a local disk cache
  */
+#define folio_fscache(folio)		folio_private_2(folio)
 #define PageFsCache(page)		PagePrivate2((page))
 #define SetPageFsCache(page)		SetPagePrivate2((page))
 #define ClearPageFsCache(page)		ClearPagePrivate2((page))
@@ -29,57 +30,77 @@
 #define TestClearPageFsCache(page)	TestClearPagePrivate2((page))
 
 /**
- * set_page_fscache - Set PG_fscache on a page and take a ref
- * @page: The page.
+ * folio_start_fscache - Start an fscache operation on a folio.
+ * @folio: The folio.
  *
- * Set the PG_fscache (PG_private_2) flag on a page and take the reference
- * needed for the VM to handle its lifetime correctly.  This sets the flag and
- * takes the reference unconditionally, so care must be taken not to set the
- * flag again if it's already set.
+ * Call this function before an fscache operation starts on a folio.
+ * Starting a second fscache operation before the first one finishes is
+ * not allowed.
  */
-static inline void set_page_fscache(struct page *page)
+static inline void folio_start_fscache(struct folio *folio)
 {
-	set_page_private_2(page);
+	VM_BUG_ON_FOLIO(folio_private_2(folio), folio);
+	folio_get(folio);
+	folio_set_private_2_flag(folio);
 }
 
 /**
- * end_page_fscache - Clear PG_fscache and release any waiters
- * @page: The page
- *
- * Clear the PG_fscache (PG_private_2) bit on a page and wake up any sleepers
- * waiting for this.  The page ref held for PG_private_2 being set is released.
+ * folio_end_fscache - End an fscache operation on a folio.
+ * @folio: The folio.
  *
- * This is, for example, used when a netfs page is being written to a local
- * disk cache, thereby allowing writes to the cache for the same page to be
- * serialised.
+ * Call this function after an fscache operation has finished.  This will
+ * wake any sleepers waiting on this folio.
  */
-static inline void end_page_fscache(struct page *page)
+static inline void folio_end_fscache(struct folio *folio)
 {
-	folio_end_private_2(page_folio(page));
+	folio_end_private_2(folio);
 }
 
 /**
- * wait_on_page_fscache - Wait for PG_fscache to be cleared on a page
- * @page: The page to wait on
+ * folio_wait_fscache - Wait for an fscache operation on this folio to end.
+ * @folio: The folio.
  *
- * Wait for PG_fscache (aka PG_private_2) to be cleared on a page.
+ * If an fscache operation is in progress on this folio, wait for it to
+ * finish.  Another fscache operation may start after this one finishes,
+ * unless the caller holds the folio lock.
  */
-static inline void wait_on_page_fscache(struct page *page)
+static inline void folio_wait_fscache(struct folio *folio)
 {
-	folio_wait_private_2(page_folio(page));
+	folio_wait_private_2(folio);
 }
 
 /**
- * wait_on_page_fscache_killable - Wait for PG_fscache to be cleared on a page
- * @page: The page to wait on
+ * folio_wait_fscache_killable - Wait for an fscache operation on this folio to end.
+ * @folio: The folio.
  *
- * Wait for PG_fscache (aka PG_private_2) to be cleared on a page or until a
- * fatal signal is received by the calling task.
+ * If an fscache operation is in progress on this folio, wait for it to
+ * finish or for a fatal signal to be received.  Another fscache operation
+ * may start after this one finishes, unless the caller holds the folio lock.
  *
  * Return:
  * - 0 if successful.
  * - -EINTR if a fatal signal was encountered.
  */
+static inline int folio_wait_fscache_killable(struct folio *folio)
+{
+	return folio_wait_private_2_killable(folio);
+}
+
+static inline void set_page_fscache(struct page *page)
+{
+	folio_start_fscache(page_folio(page));
+}
+
+static inline void end_page_fscache(struct page *page)
+{
+	folio_end_private_2(page_folio(page));
+}
+
+static inline void wait_on_page_fscache(struct page *page)
+{
+	folio_wait_private_2(page_folio(page));
+}
+
 static inline int wait_on_page_fscache_killable(struct page *page)
 {
 	return folio_wait_private_2_killable(page_folio(page));
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index f5e2e12b00fa..77e7c5a42733 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -764,22 +764,6 @@ void folio_wait_stable(struct folio *folio);
 
 void page_endio(struct page *page, bool is_write, int err);
 
-/**
- * set_page_private_2 - Set PG_private_2 on a page and take a ref
- * @page: The page.
- *
- * Set the PG_private_2 flag on a page and take the reference needed for the VM
- * to handle its lifetime correctly.  This sets the flag and takes the
- * reference unconditionally, so care must be taken not to set the flag again
- * if it's already set.
- */
-static inline void set_page_private_2(struct page *page)
-{
-	page = compound_head(page);
-	get_page(page);
-	SetPagePrivate2(page);
-}
-
 void folio_end_private_2(struct folio *folio);
 void folio_wait_private_2(struct folio *folio);
 int folio_wait_private_2_killable(struct folio *folio);
-- 
2.30.2


  parent reply	other threads:[~2021-06-14 20:35 UTC|newest]

Thread overview: 68+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-14 20:14 [PATCH v11 00/33] Memory folios Matthew Wilcox (Oracle)
2021-06-14 20:14 ` [PATCH v11 01/33] mm: Convert get_page_unless_zero() to return bool Matthew Wilcox (Oracle)
2021-06-15  6:24   ` Christoph Hellwig
2021-06-14 20:14 ` [PATCH v11 02/33] mm: Introduce struct folio Matthew Wilcox (Oracle)
2021-06-14 20:14 ` [PATCH v11 03/33] mm: Add folio_pgdat(), folio_zone() and folio_zonenum() Matthew Wilcox (Oracle)
2021-06-14 20:14 ` [PATCH v11 04/33] mm/vmstat: Add functions to account folio statistics Matthew Wilcox (Oracle)
2021-06-14 20:14 ` [PATCH v11 05/33] mm/debug: Add VM_BUG_ON_FOLIO() and VM_WARN_ON_ONCE_FOLIO() Matthew Wilcox (Oracle)
2021-06-14 20:14 ` [PATCH v11 06/33] mm: Add folio reference count functions Matthew Wilcox (Oracle)
2021-06-14 20:14 ` [PATCH v11 07/33] mm: Add folio_put() Matthew Wilcox (Oracle)
2021-06-14 20:14 ` [PATCH v11 08/33] mm: Add folio_get() Matthew Wilcox (Oracle)
2021-06-14 20:14 ` [PATCH v11 09/33] mm: Add folio_try_get_rcu() Matthew Wilcox (Oracle)
2021-06-15  6:25   ` Christoph Hellwig
2021-06-14 20:14 ` [PATCH v11 10/33] mm: Add folio flag manipulation functions Matthew Wilcox (Oracle)
2021-06-14 20:14 ` [PATCH v11 11/33] mm/lru: Add folio LRU functions Matthew Wilcox (Oracle)
2021-06-15  6:27   ` Christoph Hellwig
2021-06-14 20:14 ` [PATCH v11 12/33] mm: Handle per-folio private data Matthew Wilcox (Oracle)
2021-06-14 20:14 ` [PATCH v11 13/33] mm/filemap: Add folio_index(), folio_file_page() and folio_contains() Matthew Wilcox (Oracle)
2021-06-14 20:14 ` [PATCH v11 14/33] mm/filemap: Add folio_next_index() Matthew Wilcox (Oracle)
2021-06-14 20:14 ` [PATCH v11 15/33] mm/filemap: Add folio_offset() and folio_file_offset() Matthew Wilcox (Oracle)
2021-06-14 20:14 ` [PATCH v11 16/33] mm/util: Add folio_mapping() and folio_file_mapping() Matthew Wilcox (Oracle)
2021-06-14 20:14 ` [PATCH v11 17/33] mm/memcg: Add folio wrappers for various functions Matthew Wilcox (Oracle)
2021-06-14 20:14 ` [PATCH v11 18/33] mm/filemap: Add folio_unlock() Matthew Wilcox (Oracle)
2021-06-14 20:14 ` [PATCH v11 19/33] mm/filemap: Add folio_lock() Matthew Wilcox (Oracle)
2021-06-14 20:14 ` [PATCH v11 20/33] mm/filemap: Add folio_lock_killable() Matthew Wilcox (Oracle)
2021-06-14 20:14 ` [PATCH v11 21/33] mm/filemap: Add __folio_lock_async() Matthew Wilcox (Oracle)
2021-06-14 20:14 ` [PATCH v11 22/33] mm/filemap: Add folio_wait_locked() Matthew Wilcox (Oracle)
2021-06-14 20:14 ` [PATCH v11 23/33] mm/filemap: Add __folio_lock_or_retry() Matthew Wilcox (Oracle)
2021-06-14 20:14 ` [PATCH v11 24/33] mm/swap: Add folio_rotate_reclaimable() Matthew Wilcox (Oracle)
2021-06-15  6:29   ` Christoph Hellwig
2021-06-14 20:14 ` [PATCH v11 25/33] mm/filemap: Add folio_end_writeback() Matthew Wilcox (Oracle)
2021-06-14 20:14 ` [PATCH v11 26/33] mm/writeback: Add folio_wait_writeback() Matthew Wilcox (Oracle)
2021-06-14 20:14 ` [PATCH v11 27/33] mm/writeback: Add folio_wait_stable() Matthew Wilcox (Oracle)
2021-06-14 20:14 ` [PATCH v11 28/33] mm/filemap: Add folio_wait_bit() Matthew Wilcox (Oracle)
2021-06-14 20:14 ` [PATCH v11 29/33] mm/filemap: Add folio_wake_bit() Matthew Wilcox (Oracle)
2021-06-14 20:14 ` [PATCH v11 30/33] mm/filemap: Convert page wait queues to be folios Matthew Wilcox (Oracle)
2021-06-14 20:14 ` [PATCH v11 31/33] mm/filemap: Add folio private_2 functions Matthew Wilcox (Oracle)
2021-06-14 20:14 ` Matthew Wilcox (Oracle) [this message]
2021-06-14 20:14 ` [PATCH v11 33/33] mm: Add folio_mapped() Matthew Wilcox (Oracle)
2021-06-15  6:31   ` Christoph Hellwig
2021-06-16  9:16 ` [PATCH v11 32/33] fs/netfs: Add folio fscache functions David Howells
2021-06-16  9:19 ` [PATCH v11 01/33] mm: Convert get_page_unless_zero() to return bool David Howells
2021-06-16  9:31 ` [PATCH v11 02/33] mm: Introduce struct folio David Howells
2021-06-16  9:36 ` [PATCH v11 04/33] mm/vmstat: Add functions to account folio statistics David Howells
2021-06-16  9:54 ` [PATCH v11 05/33] mm/debug: Add VM_BUG_ON_FOLIO() and VM_WARN_ON_ONCE_FOLIO() David Howells
2021-06-16  9:55 ` [PATCH v11 06/33] mm: Add folio reference count functions David Howells
2021-06-16  9:55 ` [PATCH v11 07/33] mm: Add folio_put() David Howells
2021-06-16  9:56 ` [PATCH v11 08/33] mm: Add folio_get() David Howells
2021-06-16  9:58 ` [PATCH v11 10/33] mm: Add folio flag manipulation functions David Howells
2021-06-16 10:00 ` [PATCH v11 11/33] mm/lru: Add folio LRU functions David Howells
2021-06-16 10:03 ` [PATCH v11 13/33] mm/filemap: Add folio_index(), folio_file_page() and folio_contains() David Howells
2021-06-16 11:38   ` Matthew Wilcox
2021-06-16 10:04 ` [PATCH v11 14/33] mm/filemap: Add folio_next_index() David Howells
2021-06-16 10:05 ` [PATCH v11 15/33] mm/filemap: Add folio_offset() and folio_file_offset() David Howells
2021-06-16 10:10 ` [PATCH v11 16/33] mm/util: Add folio_mapping() and folio_file_mapping() David Howells
2021-06-16 10:13 ` [PATCH v11 18/33] mm/filemap: Add folio_unlock() David Howells
2021-06-16 10:17 ` [PATCH v11 19/33] mm/filemap: Add folio_lock() David Howells
2021-06-16 10:22 ` [PATCH v11 21/33] mm/filemap: Add __folio_lock_async() David Howells
2021-06-16 10:23 ` [PATCH v11 22/33] mm/filemap: Add folio_wait_locked() David Howells
2021-06-16 10:27 ` [PATCH v11 24/33] mm/swap: Add folio_rotate_reclaimable() David Howells
2021-06-16 11:46   ` Matthew Wilcox
2021-06-16 10:30 ` [PATCH v11 26/33] mm/writeback: Add folio_wait_writeback() David Howells
2021-06-16 11:55   ` Matthew Wilcox
2021-06-16 10:32 ` [PATCH v11 27/33] mm/writeback: Add folio_wait_stable() David Howells
2021-06-16 10:33 ` [PATCH v11 28/33] mm/filemap: Add folio_wait_bit() David Howells
2021-06-16 10:35 ` [PATCH v11 30/33] mm/filemap: Convert page wait queues to be folios David Howells
2021-06-16 10:37 ` [PATCH v11 33/33] mm: Add folio_mapped() David Howells
2021-06-16 10:41 ` [PATCH v11 02/33] mm: Introduce struct folio David Howells
2021-06-16 10:54 ` [PATCH v11 00/33] Memory folios David Howells

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210614201435.1379188-33-willy@infradead.org \
    --to=willy@infradead.org \
    --cc=akpm@linux-foundation.org \
    --cc=hch@lst.de \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=vbabka@suse.cz \
    --cc=william.kucharski@oracle.com \
    --subject='Re: [PATCH v11 32/33] fs/netfs: Add folio fscache functions' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.