Reimplement page_cache_sync_readahead() and page_cache_async_readahead()
as wrappers around versions of the function which take a readahead_control
in preparation for making do_sync_mmap_readahead() pass down an RAC
struct.
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
include/linux/pagemap.h | 64 ++++++++++++++++++++++++++++++++++-------
mm/readahead.c | 58 ++++++++-----------------------------
2 files changed, 66 insertions(+), 56 deletions(-)
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 2b613c369a2f..12ab56c3a86f 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -698,16 +698,6 @@ int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask);
void delete_from_page_cache_batch(struct address_space *mapping,
struct pagevec *pvec);
-#define VM_READAHEAD_PAGES (SZ_128K / PAGE_SIZE)
-
-void page_cache_sync_readahead(struct address_space *, struct file_ra_state *,
- struct file *, pgoff_t index, unsigned long req_count);
-void page_cache_async_readahead(struct address_space *, struct file_ra_state *,
- struct file *, struct page *, pgoff_t index,
- unsigned long req_count);
-void page_cache_ra_unbounded(struct readahead_control *,
- 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.
@@ -755,6 +745,60 @@ struct readahead_control {
._index = i, \
}
+#define VM_READAHEAD_PAGES (SZ_128K / PAGE_SIZE)
+
+void page_cache_ra_unbounded(struct readahead_control *,
+ unsigned long nr_to_read, unsigned long lookahead_count);
+void page_cache_sync_ra(struct readahead_control *, struct file_ra_state *,
+ unsigned long req_count);
+void page_cache_async_ra(struct readahead_control *, struct file_ra_state *,
+ struct page *, unsigned long req_count);
+
+/**
+ * page_cache_sync_readahead - generic file readahead
+ * @mapping: address_space which holds the pagecache and I/O vectors
+ * @ra: file_ra_state which holds the readahead state
+ * @file: Used by the filesystem for authentication.
+ * @index: Index of first page to be read.
+ * @req_count: Total number of pages being read by the caller.
+ *
+ * page_cache_sync_readahead() should be called when a cache miss happened:
+ * it will submit the read. The readahead logic may decide to piggyback more
+ * pages onto the read request if access patterns suggest it will improve
+ * performance.
+ */
+static inline
+void page_cache_sync_readahead(struct address_space *mapping,
+ struct file_ra_state *ra, struct file *file, pgoff_t index,
+ unsigned long req_count)
+{
+ DEFINE_READAHEAD(ractl, file, mapping, index);
+ page_cache_sync_ra(&ractl, ra, req_count);
+}
+
+/**
+ * page_cache_async_readahead - file readahead for marked pages
+ * @mapping: address_space which holds the pagecache and I/O vectors
+ * @ra: file_ra_state which holds the readahead state
+ * @file: Used by the filesystem for authentication.
+ * @page: The page at @index which triggered the readahead call.
+ * @index: Index of first page to be read.
+ * @req_count: Total number of pages being read by the caller.
+ *
+ * page_cache_async_readahead() should be called when a page is used which
+ * is marked as PageReadahead; this is a marker to suggest that the application
+ * has used up enough of the readahead window that we should start pulling in
+ * more pages.
+ */
+static inline
+void page_cache_async_readahead(struct address_space *mapping,
+ struct file_ra_state *ra, struct file *file,
+ struct page *page, pgoff_t index, unsigned long req_count)
+{
+ DEFINE_READAHEAD(ractl, file, mapping, index);
+ page_cache_async_ra(&ractl, ra, page, req_count);
+}
+
/**
* readahead_page - Get the next page to read.
* @rac: The current readahead request.
diff --git a/mm/readahead.c b/mm/readahead.c
index 3115ced5faae..620ac83f35cc 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -550,25 +550,9 @@ static void ondemand_readahead(struct readahead_control *ractl,
do_page_cache_ra(ractl, ra->size, ra->async_size);
}
-/**
- * page_cache_sync_readahead - generic file readahead
- * @mapping: address_space which holds the pagecache and I/O vectors
- * @ra: file_ra_state which holds the readahead state
- * @filp: passed on to ->readpage() and ->readpages()
- * @index: Index of first page to be read.
- * @req_count: Total number of pages being read by the caller.
- *
- * page_cache_sync_readahead() should be called when a cache miss happened:
- * it will submit the read. The readahead logic may decide to piggyback more
- * pages onto the read request if access patterns suggest it will improve
- * performance.
- */
-void page_cache_sync_readahead(struct address_space *mapping,
- struct file_ra_state *ra, struct file *filp,
- pgoff_t index, unsigned long req_count)
+void page_cache_sync_ra(struct readahead_control *ractl,
+ struct file_ra_state *ra, unsigned long req_count)
{
- DEFINE_READAHEAD(ractl, filp, mapping, index);
-
/* no read-ahead */
if (!ra->ra_pages)
return;
@@ -577,38 +561,20 @@ void page_cache_sync_readahead(struct address_space *mapping,
return;
/* be dumb */
- if (filp && (filp->f_mode & FMODE_RANDOM)) {
- force_page_cache_ra(&ractl, req_count);
+ if (ractl->file && (ractl->file->f_mode & FMODE_RANDOM)) {
+ force_page_cache_ra(ractl, req_count);
return;
}
/* do read-ahead */
- ondemand_readahead(&ractl, ra, false, req_count);
+ ondemand_readahead(ractl, ra, false, req_count);
}
-EXPORT_SYMBOL_GPL(page_cache_sync_readahead);
+EXPORT_SYMBOL_GPL(page_cache_sync_ra);
-/**
- * page_cache_async_readahead - file readahead for marked pages
- * @mapping: address_space which holds the pagecache and I/O vectors
- * @ra: file_ra_state which holds the readahead state
- * @filp: passed on to ->readpage() and ->readpages()
- * @page: The page at @index which triggered the readahead call.
- * @index: Index of first page to be read.
- * @req_count: Total number of pages being read by the caller.
- *
- * page_cache_async_readahead() should be called when a page is used which
- * is marked as PageReadahead; this is a marker to suggest that the application
- * has used up enough of the readahead window that we should start pulling in
- * more pages.
- */
-void
-page_cache_async_readahead(struct address_space *mapping,
- struct file_ra_state *ra, struct file *filp,
- struct page *page, pgoff_t index,
- unsigned long req_count)
+void page_cache_async_ra(struct readahead_control *ractl,
+ struct file_ra_state *ra, struct page *page,
+ unsigned long req_count)
{
- DEFINE_READAHEAD(ractl, filp, mapping, index);
-
/* no read-ahead */
if (!ra->ra_pages)
return;
@@ -624,16 +590,16 @@ page_cache_async_readahead(struct address_space *mapping,
/*
* Defer asynchronous read-ahead on IO congestion.
*/
- if (inode_read_congested(mapping->host))
+ if (inode_read_congested(ractl->mapping->host))
return;
if (blk_cgroup_congested())
return;
/* do read-ahead */
- ondemand_readahead(&ractl, ra, true, req_count);
+ ondemand_readahead(ractl, ra, true, req_count);
}
-EXPORT_SYMBOL_GPL(page_cache_async_readahead);
+EXPORT_SYMBOL_GPL(page_cache_async_ra);
ssize_t ksys_readahead(int fd, loff_t offset, size_t count)
{
--
2.28.0
