Matthew Wilcox
2020-Mar-20 14:22 UTC
[Ocfs2-devel] [PATCH v9 20/25] ext4: Convert from readpages to readahead
From: "Matthew Wilcox (Oracle)" <willy at infradead.org> Use the new readahead operation in ext4 Signed-off-by: Matthew Wilcox (Oracle) <willy at infradead.org> Reviewed-by: William Kucharski <william.kucharski at oracle.com> --- 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; -- 2.25.1
Eric Biggers
2020-Mar-20 17:37 UTC
[Ocfs2-devel] [PATCH v9 20/25] ext4: Convert from readpages to readahead
On Fri, Mar 20, 2020 at 07:22:26AM -0700, Matthew Wilcox wrote:> From: "Matthew Wilcox (Oracle)" <willy at infradead.org> > > Use the new readahead operation in ext4 > > Signed-off-by: Matthew Wilcox (Oracle) <willy at infradead.org> > Reviewed-by: William Kucharski <william.kucharski at oracle.com> > --- > fs/ext4/ext4.h | 3 +-- > fs/ext4/inode.c | 21 +++++++++------------ > fs/ext4/readpage.c | 22 ++++++++-------------- > 3 files changed, 18 insertions(+), 28 deletions(-) >Reviewed-by: Eric Biggers <ebiggers at google.com>> + 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; > }Maybe the prefetchw(&page->flags) should be included in readahead_page()? Most of the callers do it. - Eric