fs: convert mpage_readpages to mpage_readahead
Implement the new readahead aop and convert all callers (block_dev,
exfat, ext2, fat, gfs2, hpfs, isofs, jfs, nilfs2, ocfs2, omfs, qnx6,
reiserfs & udf).
The callers are all trivial except for GFS2 & OCFS2.
Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Reviewed-by: Junxiao Bi <[email protected]> # ocfs2
Reviewed-by: Joseph Qi <[email protected]> # ocfs2
Reviewed-by: Dave Chinner <[email protected]>
Reviewed-by: John Hubbard <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: William Kucharski <[email protected]>
Cc: Chao Yu <[email protected]>
Cc: Cong Wang <[email protected]>
Cc: Darrick J. Wong <[email protected]>
Cc: Eric Biggers <[email protected]>
Cc: Gao Xiang <[email protected]>
Cc: Jaegeuk Kim <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Zi Yan <[email protected]>
Cc: Johannes Thumshirn <[email protected]>
Cc: Miklos Szeredi <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>
diff --git a/fs/mpage.c b/fs/mpage.c
index ccba3c4..830e6cc 100644
--- a/fs/mpage.c
+++ b/fs/mpage.c
@@ -91,7 +91,7 @@ mpage_alloc(struct block_device *bdev,
}
/*
- * support function for mpage_readpages. The fs supplied get_block might
+ * support function for mpage_readahead. The fs supplied get_block might
* return an up to date buffer. This is used to map that buffer into
* the page, which allows readpage to avoid triggering a duplicate call
* to get_block.
@@ -338,13 +338,8 @@ static struct bio *do_mpage_readpage(struct mpage_readpage_args *args)
}
/**
- * mpage_readpages - populate an address space with some pages & start reads against them
- * @mapping: the address_space
- * @pages: The address of a list_head which contains the target pages. These
- * pages have their ->index populated and are otherwise uninitialised.
- * The page at @pages->prev has the lowest file offset, and reads should be
- * issued in @pages->prev to @pages->next order.
- * @nr_pages: The number of pages at *@pages
+ * mpage_readahead - start reads against pages
+ * @rac: Describes which pages to read.
* @get_block: The filesystem's block mapper function.
*
* This function walks the pages and the blocks within each page, building and
@@ -381,36 +376,25 @@ static struct bio *do_mpage_readpage(struct mpage_readpage_args *args)
*
* This all causes the disk requests to be issued in the correct order.
*/
-int
-mpage_readpages(struct address_space *mapping, struct list_head *pages,
- unsigned nr_pages, get_block_t get_block)
+void mpage_readahead(struct readahead_control *rac, get_block_t get_block)
{
+ struct page *page;
struct mpage_readpage_args args = {
.get_block = get_block,
.is_readahead = true,
};
- unsigned page_idx;
- for (page_idx = 0; page_idx < nr_pages; page_idx++) {
- struct page *page = lru_to_page(pages);
-
+ while ((page = readahead_page(rac))) {
prefetchw(&page->flags);
- list_del(&page->lru);
- if (!add_to_page_cache_lru(page, mapping,
- page->index,
- readahead_gfp_mask(mapping))) {
- args.page = page;
- args.nr_pages = nr_pages - page_idx;
- args.bio = do_mpage_readpage(&args);
- }
+ args.page = page;
+ args.nr_pages = readahead_count(rac);
+ args.bio = do_mpage_readpage(&args);
put_page(page);
}
- BUG_ON(!list_empty(pages));
if (args.bio)
mpage_bio_submit(REQ_OP_READ, REQ_RAHEAD, args.bio);
- return 0;
}
-EXPORT_SYMBOL(mpage_readpages);
+EXPORT_SYMBOL(mpage_readahead);
/*
* This isn't called much at all
@@ -563,7 +547,7 @@ static int __mpage_writepage(struct page *page, struct writeback_control *wbc,
* Page has buffers, but they are all unmapped. The page was
* created by pagein or read over a hole which was handled by
* block_read_full_page(). If this address_space is also
- * using mpage_readpages then this can rarely happen.
+ * using mpage_readahead then this can rarely happen.
*/
goto confused;
}
