The patch titled
Subject: mm/filemap.c: rewrite pagecache_get_page documentation
has been added to the -mm tree. Its filename is
mm-rewrite-pagecache_get_page-documentation.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-rewrite-pagecache_get_page-documentation.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-rewrite-pagecache_get_page-documentation.patch
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------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: mm/filemap.c: rewrite pagecache_get_page documentation
- These were never called PCG flags; they've been called FGP flags since
their introduction in 2014.
- The FGP_FOR_MMAP flag was misleadingly documented as if it was an
alternative to FGP_CREAT instead of an option to it.
- Rename the 'offset' parameter to 'index'.
- Capitalisation, formatting, rewording.
Link: http://lkml.kernel.org/r/20200318140253.6141-9-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Cc: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Cc: Pankaj Gupta <pankaj.gupta.linux@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/filemap.c | 55 +++++++++++++++++++++++--------------------------
1 file changed, 26 insertions(+), 29 deletions(-)
--- a/mm/filemap.c~mm-rewrite-pagecache_get_page-documentation
+++ a/mm/filemap.c
@@ -1574,42 +1574,39 @@ repeat:
EXPORT_SYMBOL(find_lock_entry);
/**
- * pagecache_get_page - find and get a page reference
- * @mapping: the address_space to search
- * @offset: the page index
- * @fgp_flags: PCG flags
- * @gfp_mask: gfp mask to use for the page cache data page allocation
- *
- * Looks up the page cache slot at @mapping & @offset.
- *
- * PCG flags modify how the page is returned.
- *
- * @fgp_flags can be:
- *
- * - FGP_ACCESSED: the page will be marked accessed
- * - FGP_LOCK: Page is return locked
- * - FGP_CREAT: If page is not present then a new page is allocated using
- * @gfp_mask and added to the page cache and the VM's LRU
- * list. The page is returned locked and with an increased
- * refcount.
- * - FGP_FOR_MMAP: Similar to FGP_CREAT, only we want to allow the caller to do
- * its own locking dance if the page is already in cache, or unlock the page
- * before returning if we had to add the page to pagecache.
+ * pagecache_get_page - Find and get a reference to a page.
+ * @mapping: The address_space to search.
+ * @index: The page index.
+ * @fgp_flags: %FGP flags modify how the page is returned.
+ * @gfp_mask: Memory allocation flags to use if %FGP_CREAT is specified.
+ *
+ * Looks up the page cache entry at @mapping & @index.
+ *
+ * @fgp_flags can be zero or more of these flags:
+ *
+ * * %FGP_ACCESSED - The page will be marked accessed.
+ * * %FGP_LOCK - The page is returned locked.
+ * * %FGP_CREAT - If no page is present then a new page is allocated using
+ * @gfp_mask and added to the page cache and the VM's LRU list.
+ * The page is returned locked and with an increased refcount.
+ * * %FGP_FOR_MMAP - The caller wants to do its own locking dance if the
+ * page is already in cache. If the page was allocated, unlock it before
+ * returning so the caller can do the same dance.
*
- * If FGP_LOCK or FGP_CREAT are specified then the function may sleep even
- * if the GFP flags specified for FGP_CREAT are atomic.
+ * If %FGP_LOCK or %FGP_CREAT are specified then the function may sleep even
+ * if the %GFP flags specified for %FGP_CREAT are atomic.
*
* If there is a page cache page, it is returned with an increased refcount.
*
- * Return: the found page or %NULL otherwise.
+ * Return: The found page or %NULL otherwise.
*/
-struct page *pagecache_get_page(struct address_space *mapping, pgoff_t offset,
- int fgp_flags, gfp_t gfp_mask)
+struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index,
+ int fgp_flags, gfp_t gfp_mask)
{
struct page *page;
repeat:
- page = find_get_entry(mapping, offset);
+ page = find_get_entry(mapping, index);
if (xa_is_value(page))
page = NULL;
if (!page)
@@ -1631,7 +1628,7 @@ repeat:
put_page(page);
goto repeat;
}
- VM_BUG_ON_PAGE(page->index != offset, page);
+ VM_BUG_ON_PAGE(page->index != index, page);
}
if (fgp_flags & FGP_ACCESSED)
@@ -1656,7 +1653,7 @@ no_page:
if (fgp_flags & FGP_ACCESSED)
__SetPageReferenced(page);
- err = add_to_page_cache_lru(page, mapping, offset, gfp_mask);
+ err = add_to_page_cache_lru(page, mapping, index, gfp_mask);
if (unlikely(err)) {
put_page(page);
page = NULL;
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
mm-improve-dump_page-for-compound-pages.patch
mm-add-pagemaph-to-the-fine-documentation.patch
mm-use-vm_fault-error-code-directly.patch
mm-rename-arguments-to-find_subpage.patch
mm-check-pagetail-in-hpage_nr_pages-even-when-thp.patch
mm-optimise-find_subpage-for-thp.patch
mm-remove-config_transparent_huge_pagecache.patch
mm-use-vm_bug_on_page-in-clear_page_dirty_for_io.patch
mm-unexport-find_get_entry.patch
mm-rewrite-pagecache_get_page-documentation.patch
proc-inline-vma_stop-into-m_stop.patch
proc-remove-m_cache_vma.patch
proc-use-ppos-instead-of-m-version.patch
seq_file-remove-m-version.patch
proc-inline-m_next_vma-into-m_next.patch
