From: "Matthew Wilcox (Oracle)"
Use the new readahead operation in iomap. Convert XFS and ZoneFS to
use it.
Signed-off-by: Matthew Wilcox (Oracle)
---
fs/iomap/buffered-io.c | 91 +++---
fs/iomap/trace.h | 2 +-
fs/xfs/xfs_aops.c | 13 +++---
fs/zonefs/super.c | 7 ++--
include/linux/iomap.h | 3 +-
5 files changed, 42 insertions(+), 74 deletions(-)
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 44303f370b2d..2bfcd5242264 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -214,9 +214,8 @@ iomap_read_end_io(struct bio *bio)
struct iomap_readpage_ctx {
struct page *cur_page;
boolcur_page_in_bio;
- boolis_readahead;
struct bio *bio;
- struct list_head*pages;
+ struct readahead_control *rac;
};
static void
@@ -307,11 +306,11 @@ iomap_readpage_actor(struct inode *inode, loff_t pos,
loff_t length, void *data,
if (ctx->bio)
submit_bio(ctx->bio);
- if (ctx->is_readahead) /* same as readahead_gfp_mask */
+ if (ctx->rac) /* same as readahead_gfp_mask */
gfp |= __GFP_NORETRY | __GFP_NOWARN;
ctx->bio = bio_alloc(gfp, min(BIO_MAX_PAGES, nr_vecs));
ctx->bio->bi_opf = REQ_OP_READ;
- if (ctx->is_readahead)
+ if (ctx->rac)
ctx->bio->bi_opf |= REQ_RAHEAD;
ctx->bio->bi_iter.bi_sector = sector;
bio_set_dev(ctx->bio, iomap->bdev);
@@ -367,36 +366,8 @@ iomap_readpage(struct page *page, const struct iomap_ops
*ops)
}
EXPORT_SYMBOL_GPL(iomap_readpage);
-static struct page *
-iomap_next_page(struct inode *inode, struct list_head *pages, loff_t pos,
- loff_t length, loff_t *done)
-{
- while (!list_empty(pages)) {
- struct page *page = lru_to_page(pages);
-
- if (page_offset(page) >= (u64)pos + length)
- break;
-
- list_del(>lru);
- if (!add_to_page_cache_lru(page, inode->i_mapping, page->index,
- GFP_NOFS))
- return page;
-
- /*
-* If we already have a page in the page cache at index we are
-* done. Upper layers don't care if it is uptodate after the
-* readpages call itself as every page gets checked again once
-* actually needed.
-*/
- *done += PAGE_SIZE;
- put_page(page);
- }
-
- return NULL;
-}
-
static loff_t
-iomap_readpages_actor(struct inode *inode, loff_t pos, loff_t length,
+iomap_readahead_actor(struct inode *inode, loff_t pos, loff_t length,
void *data, struct iomap *iomap, struct iomap *srcmap)
{
struct iomap_readpage_ctx *ctx = data;
@@ -404,10 +375,7 @@ iomap_readpages_actor(struct inode *inode, loff_t pos,
loff_t length,
while (done < length) {
if (!ctx->cur_page) {
- ctx->cur_page = iomap_next_page(inode, ctx->pages,
- pos, length, );
- if (!ctx->cur_page)
- break;
+ ctx->cur_page = readahead_page(ctx->rac);
ctx->cur_page_in_bio = false;
}
ret = iomap_readpage_actor(inode, pos + done, length - done,
@@ -416,6 +384,7 @@ iomap_readpages_actor(struct inode *inode, loff_t pos,
loff_t length,
break;
done += ret;
if (offset_in_page(pos + done) == 0) {
+ readahead_next(ctx->rac);
if (!ctx->cur_page_in_bio)
unlock_page(ctx->cur_page);
put_page(ctx->cur_page);
@@ -426,44 +395,48 @@ iomap_readpages_actor(struct inode *inode, loff_t pos,
loff_t length,
return done;
}
-int
-iomap_readpages(struct address_space *mapping, struct list_head *pages,
- unsigned nr_pages, const struct iomap_ops *ops)
+/**
+ * iomap_readahead - Attempt to read pages from a file.
+ * @rac: Describes the pages to be read.
+ * @ops: The operations vector for the filesystem.
+ *
+ * This function is for filesystems to call to implement their readahead
+ * address_space operation.
+ *
+ * Context: The file is pinned by the caller, and the pages to be read are
+ * all locked and have an elevated refcount. This function will unlock
+ * the pages (once I/O has completed on them, or I/O has been determined to
+ * not be necessary). It will also decrease the refcount once the pages
+ * have been submitted for I/O. After this point, the page may be removed
+ * from the page cache, and should not be referenced.
+ */
+void
