[PATCH v8 20/25] ext4: Convert from readpages to readahead
From: Matthew Wilcox <willy@infradead.org>
Date: 2020-02-25 21:50:41
Also in:
linux-btrfs, linux-f2fs-devel, linux-fsdevel, linux-mm, linux-xfs, lkml, ocfs2-devel
Subsystem:
ext4 file system, filesystems (vfs and infrastructure), the rest · Maintainers:
"Theodore Ts'o", Alexander Viro, Christian Brauner, Linus Torvalds
From: "Matthew Wilcox (Oracle)" <willy@infradead.org> Use the new readahead operation in ext4 Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> --- fs/ext4/ext4.h | 3 +-- fs/ext4/inode.c | 21 +++++++++------------ fs/ext4/readpage.c | 22 ++++++++-------------- 3 files changed, 18 insertions(+), 28 deletions(-)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 4441331d06cc..1570a0b51b73 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h@@ -3279,8 +3279,7 @@ static inline void ext4_set_de_type(struct super_block *sb, /* 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);
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index e60aca791d3f..d674c5f9066c 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c@@ -3226,23 +3226,20 @@ static int ext4_readpage(struct file *file, struct page *page) 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,
@@ -3587,7 +3584,7 @@ static int ext4_set_page_dirty(struct page *page) 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,
@@ -3604,7 +3601,7 @@ static const struct address_space_operations ext4_aops = { 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,
@@ -3620,7 +3617,7 @@ static const struct address_space_operations ext4_journalled_aops = { 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,
diff --git a/fs/ext4/readpage.c b/fs/ext4/readpage.c
index c1769afbf799..66275f25235d 100644
--- a/fs/ext4/readpage.c
+++ b/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(struct inode *inode) } 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_space *mapping, 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_space *mapping, 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_space *mapping, 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_space *mapping, 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;
--
2.25.0