mm: use readahead_control to pass arguments

In this patch, only between __do_page_cache_readahead() and
read_pages(), but it will be extended in upcoming patches.  The
read_pages() function becomes aops centric, as this makes the most sense
by the end of the patchset.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Chao Yu <yuchao0@huawei.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Gao Xiang <gaoxiang25@huawei.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Link: http://lkml.kernel.org/r/20200414150233.24495-7-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Matthew Wilcox (Oracle) 2020-06-01 21:46:25 -07:00 committed by Linus Torvalds
parent 042124cc64
commit a4d9653666

View File

@ -113,29 +113,32 @@ int read_cache_pages(struct address_space *mapping, struct list_head *pages,
EXPORT_SYMBOL(read_cache_pages);
static void read_pages(struct address_space *mapping, struct file *filp,
struct list_head *pages, unsigned int nr_pages, gfp_t gfp)
static void read_pages(struct readahead_control *rac, struct list_head *pages,
gfp_t gfp)
{
const struct address_space_operations *aops = rac->mapping->a_ops;
struct blk_plug plug;
unsigned page_idx;
if (!nr_pages)
if (!readahead_count(rac))
return;
blk_start_plug(&plug);
if (mapping->a_ops->readpages) {
mapping->a_ops->readpages(filp, mapping, pages, nr_pages);
if (aops->readpages) {
aops->readpages(rac->file, rac->mapping, pages,
readahead_count(rac));
/* Clean up the remaining pages */
put_pages_list(pages);
goto out;
}
for (page_idx = 0; page_idx < nr_pages; page_idx++) {
for (page_idx = 0; page_idx < readahead_count(rac); page_idx++) {
struct page *page = lru_to_page(pages);
list_del(&page->lru);
if (!add_to_page_cache_lru(page, mapping, page->index, gfp))
mapping->a_ops->readpage(filp, page);
if (!add_to_page_cache_lru(page, rac->mapping, page->index,
gfp))
aops->readpage(rac->file, page);
put_page(page);
}
@ -143,6 +146,7 @@ out:
blk_finish_plug(&plug);
BUG_ON(!list_empty(pages));
rac->_nr_pages = 0;
}
/*
@ -160,9 +164,12 @@ void __do_page_cache_readahead(struct address_space *mapping,
unsigned long end_index; /* The last page we want to read */
LIST_HEAD(page_pool);
int page_idx;
unsigned int nr_pages = 0;
loff_t isize = i_size_read(inode);
gfp_t gfp_mask = readahead_gfp_mask(mapping);
struct readahead_control rac = {
.mapping = mapping,
.file = filp,
};
if (isize == 0)
return;
@ -185,9 +192,7 @@ void __do_page_cache_readahead(struct address_space *mapping,
* contiguous pages before continuing with the next
* batch.
*/
read_pages(mapping, filp, &page_pool, nr_pages,
gfp_mask);
nr_pages = 0;
read_pages(&rac, &page_pool, gfp_mask);
continue;
}
@ -198,7 +203,7 @@ void __do_page_cache_readahead(struct address_space *mapping,
list_add(&page->lru, &page_pool);
if (page_idx == nr_to_read - lookahead_size)
SetPageReadahead(page);
nr_pages++;
rac._nr_pages++;
}
/*
@ -206,7 +211,7 @@ void __do_page_cache_readahead(struct address_space *mapping,
* uptodate then the caller will launch readpage again, and
* will then handle the error.
*/
read_pages(mapping, filp, &page_pool, nr_pages, gfp_mask);
read_pages(&rac, &page_pool, gfp_mask);
}
/*