[PATCH v10 18/25] erofs: Convert uncompressed files from readpages to readahead

Matthew Wilcox
2020-03-23T20:25:18Z

Use the new readahead operation in erofs

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Gao Xiang <gaoxiang25@huawei.com>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
---
fs/erofs/data.c | 39 +++++++++++++-----------------------
fs/erofs/zdata.c | 2 +-
include/trace/events/erofs.h | 6 +++---
3 files changed, 18 insertions(+), 29 deletions(-)

diff --git a/fs/erofs/data.c b/fs/erofs/data.c
index fc3a8d8064f8..d0542151e8c4 100644
--- a/fs/erofs/data.c
+++ b/fs/erofs/data.c
@@ -280,47 +280,36 @@ static int erofs_raw_access_readpage(struct file *file, struct page *page)
return 0;
}

-static int erofs_raw_access_readpages(struct file *filp,
- struct address_space *mapping,
- struct list_head *pages,
- unsigned int nr_pages)
+static void erofs_raw_access_readahead(struct readahead_control *rac)
{
erofs_off_t last_block;
struct bio *bio = NULL;
- gfp_t gfp = readahead_gfp_mask(mapping);
- struct page *page = list_last_entry(pages, struct page, lru);
-
- trace_erofs_readpages(mapping->host, page, nr_pages, true);
+ struct page *page;

- for (; nr_pages; --nr_pages) {
- page = list_entry(pages->prev, struct page, lru);
+ trace_erofs_readpages(rac->mapping->host, readahead_index(rac),
+ readahead_count(rac), true);

+ while ((page = readahead_page(rac))) {
prefetchw(&page->flags);
- list_del(&page->lru);

- if (!add_to_page_cache_lru(page, mapping, page->index, gfp)) {
- bio = erofs_read_raw_page(bio, mapping, page,
- &last_block, nr_pages, true);
+ bio = erofs_read_raw_page(bio, rac->mapping, page, &last_block,
+ readahead_count(rac), true);

- /* all the page errors are ignored when readahead */
- if (IS_ERR(bio)) {
- pr_err("%s, readahead error at page %lu of nid %llu\n",
- __func__, page->index,
- EROFS_I(mapping->host)->nid);
+ /* all the page errors are ignored when readahead */
+ if (IS_ERR(bio)) {
+ pr_err("%s, readahead error at page %lu of nid %llu\n",
+ __func__, page->index,
+ EROFS_I(rac->mapping->host)->nid);

- bio = NULL;
- }
+ bio = NULL;
}

- /* pages could still be locked */
put_page(page);
}
- DBG_BUGON(!list_empty(pages));

/* the rare case (end in gaps) */
if (bio)
submit_bio(bio);
- return 0;
}

static int erofs_get_block(struct inode *inode, sector_t iblock,
@@ -358,7 +347,7 @@ static sector_t erofs_bmap(struct address_space *mapping, sector_t block)
/* for uncompressed (aligned) files and raw access for other files */
const struct address_space_operations erofs_raw_access_aops = {
.readpage = erofs_raw_access_readpage,
- .readpages = erofs_raw_access_readpages,
+ .readahead = erofs_raw_access_readahead,
.bmap = erofs_bmap,
};

diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index 5086b1218aac..acbfe05b1b12 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -1317,7 +1317,7 @@ static int z_erofs_readpages(struct file *filp, struct address_space *mapping,
struct page *head = NULL;
LIST_HEAD(pagepool);

- trace_erofs_readpages(mapping->host, lru_to_page(pages),
+ trace_erofs_readpages(mapping->host, lru_to_page(pages)->index,
nr_pages, false);

f.headoffset = (erofs_off_t)lru_to_page(pages)->index << PAGE_SHIFT;
diff --git a/include/trace/events/erofs.h b/include/trace/events/erofs.h
index 27f5caa6299a..bf9806fd1306 100644
--- a/include/trace/events/erofs.h
+++ b/include/trace/events/erofs.h
@@ -113,10 +113,10 @@ TRACE_EVENT(erofs_readpage,

TRACE_EVENT(erofs_readpages,

- TP_PROTO(struct inode *inode, struct page *page, unsigned int nrpage,
+ TP_PROTO(struct inode *inode, pgoff_t start, unsigned int nrpage,
bool raw),

- TP_ARGS(inode, page, nrpage, raw),
+ TP_ARGS(inode, start, nrpage, raw),

TP_STRUCT__entry(
__field(dev_t, dev )
@@ -129,7 +129,7 @@ TRACE_EVENT(erofs_readpages,
TP_fast_assign(
__entry->dev = inode->i_sb->s_dev;
__entry->nid = EROFS_I(inode)->nid;
- __entry->start = page->index;
+ __entry->start = start;
__entry->nrpage = nrpage;
__entry->raw = raw;
),
--
2.25.1