The patch titled
Subject: ext4: convert from readpages to readahead
has been added to the -mm tree. Its filename is
ext4-convert-from-readpages-to-readahead.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/ext4-convert-from-readpages-to-readahead.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/ext4-convert-from-readpages-to-readahead.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: ext4: convert from readpages to readahead
Use the new readahead operation in ext4
Link: http://lkml.kernel.org/r/20200414150233.24495-21-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Reviewed-by: William Kucharski <william.kucharski@xxxxxxxxxx>
Reviewed-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Cc: Chao Yu <yuchao0@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Cong Wang <xiyou.wangcong@xxxxxxxxx>
Cc: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Cc: Dave Chinner <dchinner@xxxxxxxxxx>
Cc: Gao Xiang <gaoxiang25@xxxxxxxxxx>
Cc: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
Cc: John Hubbard <jhubbard@xxxxxxxxxx>
Cc: Joseph Qi <joseph.qi@xxxxxxxxxxxxxxxxx>
Cc: Junxiao Bi <junxiao.bi@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Zi Yan <ziy@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/ext4/ext4.h | 3 +--
fs/ext4/inode.c | 21 +++++++++------------
fs/ext4/readpage.c | 22 ++++++++--------------
3 files changed, 18 insertions(+), 28 deletions(-)
--- a/fs/ext4/ext4.h~ext4-convert-from-readpages-to-readahead
+++ a/fs/ext4/ext4.h
@@ -3317,8 +3317,7 @@ static inline void ext4_set_de_type(stru
/* readpages.c */
extern int ext4_mpage_readpages(struct address_space *mapping,
- struct list_head *pages, struct page *page,
- unsigned nr_pages, bool is_readahead);
+ struct readahead_control *rac, struct page *page);
extern int __init ext4_init_post_read_processing(void);
extern void ext4_exit_post_read_processing(void);
--- a/fs/ext4/inode.c~ext4-convert-from-readpages-to-readahead
+++ a/fs/ext4/inode.c
@@ -3224,23 +3224,20 @@ static int ext4_readpage(struct file *fi
ret = ext4_readpage_inline(inode, page);
if (ret == -EAGAIN)
- return ext4_mpage_readpages(page->mapping, NULL, page, 1,
- false);
+ return ext4_mpage_readpages(page->mapping, NULL, page);
return ret;
}
-static int
-ext4_readpages(struct file *file, struct address_space *mapping,
- struct list_head *pages, unsigned nr_pages)
+static void ext4_readahead(struct readahead_control *rac)
{
- struct inode *inode = mapping->host;
+ struct inode *inode = rac->mapping->host;
- /* If the file has inline data, no need to do readpages. */
+ /* If the file has inline data, no need to do readahead. */
if (ext4_has_inline_data(inode))
- return 0;
+ return;
- return ext4_mpage_readpages(mapping, pages, NULL, nr_pages, true);
+ ext4_mpage_readpages(rac->mapping, rac, NULL);
}
static void ext4_invalidatepage(struct page *page, unsigned int offset,
@@ -3605,7 +3602,7 @@ static int ext4_set_page_dirty(struct pa
static const struct address_space_operations ext4_aops = {
.readpage = ext4_readpage,
- .readpages = ext4_readpages,
+ .readahead = ext4_readahead,
.writepage = ext4_writepage,
.writepages = ext4_writepages,
.write_begin = ext4_write_begin,
@@ -3622,7 +3619,7 @@ static const struct address_space_operat
static const struct address_space_operations ext4_journalled_aops = {
.readpage = ext4_readpage,
- .readpages = ext4_readpages,
+ .readahead = ext4_readahead,
.writepage = ext4_writepage,
.writepages = ext4_writepages,
.write_begin = ext4_write_begin,
@@ -3638,7 +3635,7 @@ static const struct address_space_operat
static const struct address_space_operations ext4_da_aops = {
.readpage = ext4_readpage,
- .readpages = ext4_readpages,
+ .readahead = ext4_readahead,
.writepage = ext4_writepage,
.writepages = ext4_writepages,
.write_begin = ext4_da_write_begin,
--- a/fs/ext4/readpage.c~ext4-convert-from-readpages-to-readahead
+++ a/fs/ext4/readpage.c
@@ -7,8 +7,8 @@
*
* This was originally taken from fs/mpage.c
*
- * The intent is the ext4_mpage_readpages() function here is intended
- * to replace mpage_readpages() in the general case, not just for
+ * The ext4_mpage_readpages() function here is intended to
+ * replace mpage_readahead() in the general case, not just for
* encrypted files. It has some limitations (see below), where it
* will fall back to read_block_full_page(), but these limitations
* should only be hit when page_size != block_size.
@@ -222,8 +222,7 @@ static inline loff_t ext4_readpage_limit
}
int ext4_mpage_readpages(struct address_space *mapping,
- struct list_head *pages, struct page *page,
- unsigned nr_pages, bool is_readahead)
+ struct readahead_control *rac, struct page *page)
{
struct bio *bio = NULL;
sector_t last_block_in_bio = 0;
@@ -241,6 +240,7 @@ int ext4_mpage_readpages(struct address_
int length;
unsigned relative_block = 0;
struct ext4_map_blocks map;
+ unsigned int nr_pages = rac ? readahead_count(rac) : 1;
map.m_pblk = 0;
map.m_lblk = 0;
@@ -251,14 +251,9 @@ int ext4_mpage_readpages(struct address_
int fully_mapped = 1;
unsigned first_hole = blocks_per_page;
- if (pages) {
- page = lru_to_page(pages);
-
+ if (rac) {
+ 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)))
- goto next_page;
}
if (page_has_buffers(page))
@@ -381,7 +376,7 @@ int ext4_mpage_readpages(struct address_
bio->bi_iter.bi_sector = blocks[0] << (blkbits - 9);
bio->bi_end_io = mpage_end_io;
bio_set_op_attrs(bio, REQ_OP_READ,
- is_readahead ? REQ_RAHEAD : 0);
+ rac ? REQ_RAHEAD : 0);
}
length = first_hole << blkbits;
@@ -406,10 +401,9 @@ int ext4_mpage_readpages(struct address_
else
unlock_page(page);
next_page:
- if (pages)
+ if (rac)
put_page(page);
}
- BUG_ON(pages && !list_empty(pages));
if (bio)
submit_bio(bio);
return 0;
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
mm-move-readahead-prototypes-from-mmh.patch
mm-return-void-from-various-readahead-functions.patch
mm-ignore-return-value-of-readpages.patch
mm-move-readahead-nr_pages-check-into-read_pages.patch
mm-add-new-readahead_control-api.patch
mm-use-readahead_control-to-pass-arguments.patch
mm-rename-various-offset-parameters-to-index.patch
mm-rename-readahead-loop-variable-to-i.patch
mm-remove-page_offset-from-readahead-loop.patch
mm-put-readahead-pages-in-cache-earlier.patch
mm-add-readahead-address-space-operation.patch
mm-move-end_index-check-out-of-readahead-loop.patch
mm-add-page_cache_readahead_unbounded.patch
mm-document-why-we-dont-set-pagereadahead.patch
mm-use-memalloc_nofs_save-in-readahead-path.patch
fs-convert-mpage_readpages-to-mpage_readahead.patch
btrfs-convert-from-readpages-to-readahead.patch
erofs-convert-uncompressed-files-from-readpages-to-readahead.patch
erofs-convert-compressed-files-from-readpages-to-readahead.patch
ext4-convert-from-readpages-to-readahead.patch
ext4-pass-the-inode-to-ext4_mpage_readpages.patch
f2fs-convert-from-readpages-to-readahead.patch
f2fs-pass-the-inode-to-f2fs_mpage_readpages.patch
fuse-convert-from-readpages-to-readahead.patch
iomap-convert-from-readpages-to-readahead.patch
