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From: Matthew Wilcox <willy@infradead.org>
To: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Subject: [PATCH 03/15] mm: Add file_offset_of_ helpers
Date: Tue, 24 Sep 2019 17:52:02 -0700	[thread overview]
Message-ID: <20190925005214.27240-4-willy@infradead.org> (raw)
In-Reply-To: <20190925005214.27240-1-willy@infradead.org>

From: "Matthew Wilcox (Oracle)" <willy@infradead.org>

The page_offset function is badly named for people reading the functions
which call it.  The natural meaning of a function with this name would
be 'offset within a page', not 'page offset in bytes within a file'.
Dave Chinner suggests file_offset_of_page() as a replacement function
name and I'm also adding file_offset_of_next_page() as a helper for the
large page work.  Also add kernel-doc for these functions so they show
up in the kernel API book.

page_offset() is retained as a compatibility define for now.
---
 drivers/net/ethernet/ibm/ibmveth.c |  2 --
 include/linux/pagemap.h            | 25 ++++++++++++++++++++++---
 2 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/ibm/ibmveth.c b/drivers/net/ethernet/ibm/ibmveth.c
index c5be4ebd8437..bf98aeaf9a45 100644
--- a/drivers/net/ethernet/ibm/ibmveth.c
+++ b/drivers/net/ethernet/ibm/ibmveth.c
@@ -978,8 +978,6 @@ static int ibmveth_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 	return -EOPNOTSUPP;
 }
 
-#define page_offset(v) ((unsigned long)(v) & ((1 << 12) - 1))
-
 static int ibmveth_send(struct ibmveth_adapter *adapter,
 			union ibmveth_buf_desc *descs, unsigned long mss)
 {
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 750770a2c685..103205494ea0 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -428,14 +428,33 @@ static inline pgoff_t page_to_pgoff(struct page *page)
 	return page_to_index(page);
 }
 
-/*
- * Return byte-offset into filesystem object for page.
+/**
+ * file_offset_of_page - File offset of this page.
+ * @page: Page cache page.
+ *
+ * Context: Any context.
+ * Return: The offset of the first byte of this page.
  */
-static inline loff_t page_offset(struct page *page)
+static inline loff_t file_offset_of_page(struct page *page)
 {
 	return ((loff_t)page->index) << PAGE_SHIFT;
 }
 
+/* Legacy; please convert callers */
+#define page_offset(page)	file_offset_of_page(page)
+
+/**
+ * file_offset_of_next_page - File offset of the next page.
+ * @page: Page cache page.
+ *
+ * Context: Any context.
+ * Return: The offset of the first byte after this page.
+ */
+static inline loff_t file_offset_of_next_page(struct page *page)
+{
+	return ((loff_t)page->index + compound_nr(page)) << PAGE_SHIFT;
+}
+
 static inline loff_t page_file_offset(struct page *page)
 {
 	return ((loff_t)page_index(page)) << PAGE_SHIFT;
-- 
2.23.0


  parent reply	other threads:[~2019-09-25  0:53 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-25  0:51 [RFC 00/15] Large pages in the page-cache Matthew Wilcox
2019-09-25  0:52 ` [PATCH 01/15] mm: Use vm_fault error code directly Matthew Wilcox
2019-09-26 13:55   ` Kirill A. Shutemov
2019-09-25  0:52 ` [PATCH 02/15] fs: Introduce i_blocks_per_page Matthew Wilcox
2019-09-25  8:36   ` Dave Chinner
2019-10-04 19:28     ` Matthew Wilcox
2019-10-08  3:53       ` Dave Chinner
2019-09-25  0:52 ` Matthew Wilcox [this message]
2019-09-26 14:02   ` [PATCH 03/15] mm: Add file_offset_of_ helpers Kirill A. Shutemov
2019-10-04 19:39     ` Matthew Wilcox
2019-09-25  0:52 ` [PATCH 04/15] iomap: Support large pages Matthew Wilcox
2019-09-25  0:52 ` [PATCH 05/15] xfs: " Matthew Wilcox
2019-09-25  0:52 ` [PATCH 06/15] xfs: Pass a page to xfs_finish_page_writeback Matthew Wilcox
2019-09-25  0:52 ` [PATCH 07/15] mm: Make prep_transhuge_page tail-callable Matthew Wilcox
2019-09-26 14:13   ` Kirill A. Shutemov
2019-09-25  0:52 ` [PATCH 08/15] mm: Add __page_cache_alloc_order Matthew Wilcox
2019-09-26 14:15   ` Kirill A. Shutemov
2019-09-25  0:52 ` [PATCH 09/15] mm: Allow large pages to be added to the page cache Matthew Wilcox
2019-09-26 14:22   ` Kirill A. Shutemov
2019-09-25  0:52 ` [PATCH 10/15] mm: Allow find_get_page to be used for large pages Matthew Wilcox
2019-10-01 10:32   ` Kirill A. Shutemov
2019-09-25  0:52 ` [PATCH 11/15] mm: Remove hpage_nr_pages Matthew Wilcox
2019-10-01 10:35   ` Kirill A. Shutemov
2019-09-25  0:52 ` [PATCH 12/15] mm: Support removing arbitrary sized pages from mapping Matthew Wilcox
2019-10-01 10:39   ` Kirill A. Shutemov
2019-09-25  0:52 ` [PATCH 13/15] mm: Add a huge page fault handler for files Matthew Wilcox
2019-10-01 10:42   ` Kirill A. Shutemov
2019-09-25  0:52 ` [PATCH 14/15] mm: Align THP mappings for non-DAX Matthew Wilcox
2019-10-01 10:45   ` Kirill A. Shutemov
2019-10-01 11:21     ` William Kucharski
2019-10-01 11:32       ` Kirill A. Shutemov
2019-10-01 12:18         ` William Kucharski
2019-10-01 14:20           ` Kirill A. Shutemov
2019-10-01 16:08             ` William Kucharski
2019-10-02  0:15               ` Kirill A. Shutemov
2019-09-25  0:52 ` [PATCH 15/15] xfs: Use filemap_huge_fault Matthew Wilcox
     [not found] ` <20191002130753.7680-1-hdanton@sina.com>
2019-10-04 19:33   ` [PATCH 03/15] mm: Add file_offset_of_ helpers Matthew Wilcox
     [not found] ` <20191002133211.15696-1-hdanton@sina.com>
2019-10-04 19:34   ` [PATCH 04/15] iomap: Support large pages Matthew Wilcox
     [not found] ` <20191003040846.17604-1-hdanton@sina.com>
2019-10-04 19:35   ` [PATCH 06/15] xfs: Pass a page to xfs_finish_page_writeback Matthew Wilcox
     [not found] ` <20191003050859.18140-1-hdanton@sina.com>
2019-10-04 19:36   ` [PATCH 11/15] mm: Remove hpage_nr_pages Matthew Wilcox

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