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) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com> # ocfs2
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> # ocfs2
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Cc: Chao Yu <yuchao0@huawei.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Gao Xiang <gaoxiang25@huawei.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Link: http://lkml.kernel.org/r/20200414150233.24495-17-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Matthew Wilcox (Oracle)
2020-06-01 21:47:02 -07:00
committed by Linus Torvalds
parent f2c817bed5
commit d4388340ae
18 changed files with 73 additions and 126 deletions

View File

@@ -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 @@ confused:
}
/**
* 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 @@ confused:
*
* 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;
}