Re: [Ocfs2-devel] [PATCH v6 10/19] fs: Convert mpage_readpages to mpage_readahead

Joseph Qi
2020-02-18T01:51:41Z

On 20/2/18 02:45, Matthew Wilcox wrote:
> From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
>
> 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>
> Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com> # ocfs2
> ---
> drivers/staging/exfat/exfat_super.c | 7 +++---
> fs/block_dev.c | 7 +++---
> fs/ext2/inode.c | 10 +++-----
> fs/fat/inode.c | 7 +++---
> fs/gfs2/aops.c | 23 ++++++-----------
> fs/hpfs/file.c | 7 +++---
> fs/iomap/buffered-io.c | 2 +-
> fs/isofs/inode.c | 7 +++---
> fs/jfs/inode.c | 7 +++---
> fs/mpage.c | 38 +++++++++--------------------
> fs/nilfs2/inode.c | 15 +++---------
> fs/ocfs2/aops.c | 34 ++++++++++----------------
> fs/omfs/file.c | 7 +++---
> fs/qnx6/inode.c | 7 +++---
> fs/reiserfs/inode.c | 8 +++---
> fs/udf/inode.c | 7 +++---
> include/linux/mpage.h | 4 +--
> mm/migrate.c | 2 +-
> 18 files changed, 73 insertions(+), 126 deletions(-)
>
> diff --git a/drivers/staging/exfat/exfat_super.c b/drivers/staging/exfat/exfat_super.c
> index b81d2a87b82e..96aad9b16d31 100644
> --- a/drivers/staging/exfat/exfat_super.c
> +++ b/drivers/staging/exfat/exfat_super.c
> @@ -3002,10 +3002,9 @@ static int exfat_readpage(struct file *file, struct page *page)
> return mpage_readpage(page, exfat_get_block);
> }
>
> -static int exfat_readpages(struct file *file, struct address_space *mapping,
> - struct list_head *pages, unsigned int nr_pages)
> +static void exfat_readahead(struct readahead_control *rac)
> {
> - return mpage_readpages(mapping, pages, nr_pages, exfat_get_block);
> + mpage_readahead(rac, exfat_get_block);
> }
>
> static int exfat_writepage(struct page *page, struct writeback_control *wbc)
> @@ -3104,7 +3103,7 @@ static sector_t _exfat_bmap(struct address_space *mapping, sector_t block)
>
> static const struct address_space_operations exfat_aops = {
> .readpage = exfat_readpage,
> - .readpages = exfat_readpages,
> + .readahead = exfat_readahead,
> .writepage = exfat_writepage,
> .writepages = exfat_writepages,
> .write_begin = exfat_write_begin,
> diff --git a/fs/block_dev.c b/fs/block_dev.c
> index 69bf2fb6f7cd..2fd9c7bd61f6 100644
> --- a/fs/block_dev.c
> +++ b/fs/block_dev.c
> @@ -614,10 +614,9 @@ static int blkdev_readpage(struct file * file, struct page * page)
> return block_read_full_page(page, blkdev_get_block);
> }
>
> -static int blkdev_readpages(struct file *file, struct address_space *mapping,
> - struct list_head *pages, unsigned nr_pages)
> +static void blkdev_readahead(struct readahead_control *rac)
> {
> - return mpage_readpages(mapping, pages, nr_pages, blkdev_get_block);
> + mpage_readahead(rac, blkdev_get_block);
> }
>
> static int blkdev_write_begin(struct file *file, struct address_space *mapping,
> @@ -2062,7 +2061,7 @@ static int blkdev_writepages(struct address_space *mapping,
>
> static const struct address_space_operations def_blk_aops = {
> .readpage = blkdev_readpage,
> - .readpages = blkdev_readpages,
> + .readahead = blkdev_readahead,
> .writepage = blkdev_writepage,
> .write_begin = blkdev_write_begin,
> .write_end = blkdev_write_end,
> diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
> index c885cf7d724b..2875c0a705b5 100644
> --- a/fs/ext2/inode.c
> +++ b/fs/ext2/inode.c
> @@ -877,11 +877,9 @@ static int ext2_readpage(struct file *file, struct page *page)
> return mpage_readpage(page, ext2_get_block);
> }
>
> -static int
> -ext2_readpages(struct file *file, struct address_space *mapping,
> - struct list_head *pages, unsigned nr_pages)
> +static void ext2_readahead(struct readahead_control *rac)
> {
> - return mpage_readpages(mapping, pages, nr_pages, ext2_get_block);
> + mpage_readahead(rac, ext2_get_block);
> }
>
> static int
> @@ -967,7 +965,7 @@ ext2_dax_writepages(struct address_space *mapping, struct writeback_control *wbc
>
> const struct address_space_operations ext2_aops = {
> .readpage = ext2_readpage,
> - .readpages = ext2_readpages,
> + .readahead = ext2_readahead,
> .writepage = ext2_writepage,
> .write_begin = ext2_write_begin,
> .write_end = ext2_write_end,
> @@ -981,7 +979,7 @@ const struct address_space_operations ext2_aops = {
>
> const struct address_space_operations ext2_nobh_aops = {
> .readpage = ext2_readpage,
> - .readpages = ext2_readpages,
> + .readahead = ext2_readahead,
> .writepage = ext2_nobh_writepage,
> .write_begin = ext2_nobh_write_begin,
> .write_end = nobh_write_end,
> diff --git a/fs/fat/inode.c b/fs/fat/inode.c
> index 594b05ae16c9..3496f5fc3e6d 100644
> --- a/fs/fat/inode.c
> +++ b/fs/fat/inode.c
> @@ -210,10 +210,9 @@ static int fat_readpage(struct file *file, struct page *page)
> return mpage_readpage(page, fat_get_block);
> }
>
> -static int fat_readpages(struct file *file, struct address_space *mapping,
> - struct list_head *pages, unsigned nr_pages)
> +static void fat_readahead(struct readahead_control *rac)
> {
> - return mpage_readpages(mapping, pages, nr_pages, fat_get_block);
> + mpage_readahead(rac, fat_get_block);
> }
>
> static void fat_write_failed(struct address_space *mapping, loff_t to)
> @@ -344,7 +343,7 @@ int fat_block_truncate_page(struct inode *inode, loff_t from)
>
> static const struct address_space_operations fat_aops = {
> .readpage = fat_readpage,
> - .readpages = fat_readpages,
> + .readahead = fat_readahead,
> .writepage = fat_writepage,
> .writepages = fat_writepages,
> .write_begin = fat_write_begin,
> diff --git a/fs/gfs2/aops.c b/fs/gfs2/aops.c
> index ba83b49ce18c..5e63c13c12c1 100644
> --- a/fs/gfs2/aops.c
> +++ b/fs/gfs2/aops.c
> @@ -577,7 +577,7 @@ int gfs2_internal_read(struct gfs2_inode *ip, char *buf, loff_t *pos,
> }
>
> /**
> - * gfs2_readpages - Read a bunch of pages at once
> + * gfs2_readahead - Read a bunch of pages at once
> * @file: The file to read from
> * @mapping: Address space info
> * @pages: List of pages to read
> @@ -590,31 +590,24 @@ int gfs2_internal_read(struct gfs2_inode *ip, char *buf, loff_t *pos,
> * obviously not something we'd want to do on too regular a basis.
> * Any I/O we ignore at this time will be done via readpage later.
> * 2. We don't handle stuffed files here we let readpage do the honours.
> - * 3. mpage_readpages() does most of the heavy lifting in the common case.
> + * 3. mpage_readahead() does most of the heavy lifting in the common case.
> * 4. gfs2_block_map() is relied upon to set BH_Boundary in the right places.
> */
>
> -static int gfs2_readpages(struct file *file, struct address_space *mapping,
> - struct list_head *pages, unsigned nr_pages)
> +static void gfs2_readahead(struct readahead_control *rac)
> {
> - struct inode *inode = mapping->host;
> + struct inode *inode = rac->mapping->host;
> struct gfs2_inode *ip = GFS2_I(inode);
> - struct gfs2_sbd *sdp = GFS2_SB(inode);
> struct gfs2_holder gh;
> - int ret;
>
> gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
> - ret = gfs2_glock_nq(&gh);
> - if (unlikely(ret))
> + if (gfs2_glock_nq(&gh))
> goto out_uninit;
> if (!gfs2_is_stuffed(ip))
> - ret = mpage_readpages(mapping, pages, nr_pages, gfs2_block_map);
> + mpage_readahead(rac, gfs2_block_map);
> gfs2_glock_dq(&gh);
> out_uninit:
> gfs2_holder_uninit(&gh);
> - if (unlikely(gfs2_withdrawn(sdp)))
> - ret = -EIO;
> - return ret;
> }
>
> /**
> @@ -828,7 +821,7 @@ static const struct address_space_operations gfs2_aops = {
> .writepage = gfs2_writepage,
> .writepages = gfs2_writepages,
> .readpage = gfs2_readpage,
> - .readpages = gfs2_readpages,
> + .readahead = gfs2_readahead,
> .bmap = gfs2_bmap,
> .invalidatepage = gfs2_invalidatepage,
> .releasepage = gfs2_releasepage,
> @@ -842,7 +835,7 @@ static const struct address_space_operations gfs2_jdata_aops = {
> .writepage = gfs2_jdata_writepage,
> .writepages = gfs2_jdata_writepages,
> .readpage = gfs2_readpage,
> - .readpages = gfs2_readpages,
> + .readahead = gfs2_readahead,
> .set_page_dirty = jdata_set_page_dirty,
> .bmap = gfs2_bmap,
> .invalidatepage = gfs2_invalidatepage,
> diff --git a/fs/hpfs/file.c b/fs/hpfs/file.c
> index b36abf9cb345..2de0d3492d15 100644
> --- a/fs/hpfs/file.c
> +++ b/fs/hpfs/file.c
> @@ -125,10 +125,9 @@ static int hpfs_writepage(struct page *page, struct writeback_control *wbc)
> return block_write_full_page(page, hpfs_get_block, wbc);
> }
>
> -static int hpfs_readpages(struct file *file, struct address_space *mapping,
> - struct list_head *pages, unsigned nr_pages)
> +static void hpfs_readahead(struct readahead_control *rac)
> {
> - return mpage_readpages(mapping, pages, nr_pages, hpfs_get_block);
> + mpage_readahead(rac, hpfs_get_block);
> }
>
> static int hpfs_writepages(struct address_space *mapping,
> @@ -198,7 +197,7 @@ static int hpfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
> const struct address_space_operations hpfs_aops = {
> .readpage = hpfs_readpage,
> .writepage = hpfs_writepage,
> - .readpages = hpfs_readpages,
> + .readahead = hpfs_readahead,
> .writepages = hpfs_writepages,
> .write_begin = hpfs_write_begin,
> .write_end = hpfs_write_end,
> diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
> index 7c84c4c027c4..cb3511eb152a 100644
> --- a/fs/iomap/buffered-io.c
> +++ b/fs/iomap/buffered-io.c
> @@ -359,7 +359,7 @@ iomap_readpage(struct page *page, const struct iomap_ops *ops)
> }
>
> /*
> - * Just like mpage_readpages and block_read_full_page we always
> + * Just like mpage_readahead and block_read_full_page we always
> * return 0 and just mark the page as PageError on errors. This
> * should be cleaned up all through the stack eventually.
> */
> diff --git a/fs/isofs/inode.c b/fs/isofs/inode.c
> index 62c0462dc89f..95b1f377ad09 100644
> --- a/fs/isofs/inode.c
> +++ b/fs/isofs/inode.c
> @@ -1185,10 +1185,9 @@ static int isofs_readpage(struct file *file, struct page *page)
> return mpage_readpage(page, isofs_get_block);
> }
>
> -static int isofs_readpages(struct file *file, struct address_space *mapping,
> - struct list_head *pages, unsigned nr_pages)
> +static void isofs_readahead(struct readahead_control *rac)
> {
> - return mpage_readpages(mapping, pages, nr_pages, isofs_get_block);
> + mpage_readahead(rac, isofs_get_block);
> }
>
> static sector_t _isofs_bmap(struct address_space *mapping, sector_t block)
> @@ -1198,7 +1197,7 @@ static sector_t _isofs_bmap(struct address_space *mapping, sector_t block)
>
> static const struct address_space_operations isofs_aops = {
> .readpage = isofs_readpage,
> - .readpages = isofs_readpages,
> + .readahead = isofs_readahead,
> .bmap = _isofs_bmap
> };
>
> diff --git a/fs/jfs/inode.c b/fs/jfs/inode.c
> index 9486afcdac76..6f65bfa9f18d 100644
> --- a/fs/jfs/inode.c
> +++ b/fs/jfs/inode.c
> @@ -296,10 +296,9 @@ static int jfs_readpage(struct file *file, struct page *page)
> return mpage_readpage(page, jfs_get_block);
> }
>
> -static int jfs_readpages(struct file *file, struct address_space *mapping,
> - struct list_head *pages, unsigned nr_pages)
> +static void jfs_readahead(struct readahead_control *rac)
> {
> - return mpage_readpages(mapping, pages, nr_pages, jfs_get_block);
> + mpage_readahead(rac, jfs_get_block);
> }
>
> static void jfs_write_failed(struct address_space *mapping, loff_t to)
> @@ -358,7 +357,7 @@ static ssize_t jfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
>
> const struct address_space_operations jfs_aops = {
> .readpage = jfs_readpage,
> - .readpages = jfs_readpages,
> + .readahead = jfs_readahead,
> .writepage = jfs_writepage,
> .writepages = jfs_writepages,
> .write_begin = jfs_write_begin,
> diff --git a/fs/mpage.c b/fs/mpage.c
> index ccba3c4c4479..8a09e6002dc2 100644
> --- a/fs/mpage.c
> +++ b/fs/mpage.c
> @@ -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 @@ static struct bio *do_mpage_readpage(struct mpage_readpage_args *args)
> }
>
> /**
> - * 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 @@ static struct bio *do_mpage_readpage(struct mpage_readpage_args *args)
> *
> * 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);
>
> + readahead_for_each(rac, page) {
> 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;
> }
> diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c
> index 671085512e0f..ceeb3b441844 100644
> --- a/fs/nilfs2/inode.c
> +++ b/fs/nilfs2/inode.c
> @@ -145,18 +145,9 @@ static int nilfs_readpage(struct file *file, struct page *page)
> return mpage_readpage(page, nilfs_get_block);
> }
>
> -/**
> - * nilfs_readpages() - implement readpages() method of nilfs_aops {}
> - * address_space_operations.
> - * @file - file struct of the file to be read
> - * @mapping - address_space struct used for reading multiple pages
> - * @pages - the pages to be read
> - * @nr_pages - number of pages to be read
> - */
> -static int nilfs_readpages(struct file *file, struct address_space *mapping,
> - struct list_head *pages, unsigned int nr_pages)
> +static void nilfs_readahead(struct readahead_control *rac)
> {
> - return mpage_readpages(mapping, pages, nr_pages, nilfs_get_block);
> + mpage_readahead(rac, nilfs_get_block);
> }
>
> static int nilfs_writepages(struct address_space *mapping,
> @@ -308,7 +299,7 @@ const struct address_space_operations nilfs_aops = {
> .readpage = nilfs_readpage,
> .writepages = nilfs_writepages,
> .set_page_dirty = nilfs_set_page_dirty,
> - .readpages = nilfs_readpages,
> + .readahead = nilfs_readahead,
> .write_begin = nilfs_write_begin,
> .write_end = nilfs_write_end,
> /* .releasepage = nilfs_releasepage, */
> diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
> index 3a67a6518ddf..e8137efaafec 100644
> --- a/fs/ocfs2/aops.c
> +++ b/fs/ocfs2/aops.c
> @@ -350,14 +350,11 @@ static int ocfs2_readpage(struct file *file, struct page *page)
> * grow out to a tree. If need be, detecting boundary extents could
> * trivially be added in a future version of ocfs2_get_block().
> */
> -static int ocfs2_readpages(struct file *filp, struct address_space *mapping,
> - struct list_head *pages, unsigned nr_pages)
> +static void ocfs2_readahead(struct readahead_control *rac)
> {
> - int ret, err = -EIO;
> - struct inode *inode = mapping->host;
> + int ret;
> + struct inode *inode = rac->mapping->host;
> struct ocfs2_inode_info *oi = OCFS2_I(inode);
> - loff_t start;
> - struct page *last;
>
> /*
> * Use the nonblocking flag for the dlm code to avoid page
> @@ -365,36 +362,31 @@ static int ocfs2_readpages(struct file *filp, struct address_space *mapping,
> */
> ret = ocfs2_inode_lock_full(inode, NULL, 0, OCFS2_LOCK_NONBLOCK);
> if (ret)
> - return err;
> + return;
>
> - if (down_read_trylock(&oi->ip_alloc_sem) == 0) {
> - ocfs2_inode_unlock(inode, 0);
> - return err;
> - }
> + if (down_read_trylock(&oi->ip_alloc_sem) == 0)
> + goto out_unlock;
>
> /*
> * Don't bother with inline-data. There isn't anything
> * to read-ahead in that case anyway...
> */
> if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
> - goto out_unlock;
> + goto out_up;
>
> /*
> * Check whether a remote node truncated this file - we just
> * drop out in that case as it's not worth handling here.
> */
> - last = lru_to_page(pages);
> - start = (loff_t)last->index << PAGE_SHIFT;
> - if (start >= i_size_read(inode))
> - goto out_unlock;
> + if (readahead_offset(rac) >= i_size_read(inode))
> + goto out_up;
>
> - err = mpage_readpages(mapping, pages, nr_pages, ocfs2_get_block);
> + mpage_readahead(rac, ocfs2_get_block);
>
> -out_unlock:
> +out_up:
> up_read(&oi->ip_alloc_sem);
> +out_unlock:
> ocfs2_inode_unlock(inode, 0);
> -
> - return err;
> }
>
> /* Note: Because we don't support holes, our allocation has
> @@ -2474,7 +2466,7 @@ static ssize_t ocfs2_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
>
> const struct address_space_operations ocfs2_aops = {
> .readpage = ocfs2_readpage,
> - .readpages = ocfs2_readpages,
> + .readahead = ocfs2_readahead,
> .writepage = ocfs2_writepage,
> .write_begin = ocfs2_write_begin,
> .write_end = ocfs2_write_end,
For ocfs2 part, looks good.
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>

> diff --git a/fs/omfs/file.c b/fs/omfs/file.c
> index d640b9388238..d7b5f09d298c 100644
> --- a/fs/omfs/file.c
> +++ b/fs/omfs/file.c
> @@ -289,10 +289,9 @@ static int omfs_readpage(struct file *file, struct page *page)
> return block_read_full_page(page, omfs_get_block);
> }
>
> -static int omfs_readpages(struct file *file, struct address_space *mapping,
> - struct list_head *pages, unsigned nr_pages)
> +static void omfs_readahead(struct readahead_control *rac)
> {
> - return mpage_readpages(mapping, pages, nr_pages, omfs_get_block);
> + mpage_readahead(rac, omfs_get_block);
> }
>
> static int omfs_writepage(struct page *page, struct writeback_control *wbc)
> @@ -373,7 +372,7 @@ const struct inode_operations omfs_file_inops = {
>
> const struct address_space_operations omfs_aops = {
> .readpage = omfs_readpage,
> - .readpages = omfs_readpages,
> + .readahead = omfs_readahead,
> .writepage = omfs_writepage,
> .writepages = omfs_writepages,
> .write_begin = omfs_write_begin,
> diff --git a/fs/qnx6/inode.c b/fs/qnx6/inode.c
> index 345db56c98fd..755293c8c71a 100644
> --- a/fs/qnx6/inode.c
> +++ b/fs/qnx6/inode.c
> @@ -99,10 +99,9 @@ static int qnx6_readpage(struct file *file, struct page *page)
> return mpage_readpage(page, qnx6_get_block);
> }
>
> -static int qnx6_readpages(struct file *file, struct address_space *mapping,
> - struct list_head *pages, unsigned nr_pages)
> +static void qnx6_readahead(struct readahead_control *rac)
> {
> - return mpage_readpages(mapping, pages, nr_pages, qnx6_get_block);
> + mpage_readahead(rac, qnx6_get_block);
> }
>
> /*
> @@ -499,7 +498,7 @@ static sector_t qnx6_bmap(struct address_space *mapping, sector_t block)
> }
> static const struct address_space_operations qnx6_aops = {
> .readpage = qnx6_readpage,
> - .readpages = qnx6_readpages,
> + .readahead = qnx6_readahead,
> .bmap = qnx6_bmap
> };
>
> diff --git a/fs/reiserfs/inode.c b/fs/reiserfs/inode.c
> index 6419e6dacc39..0031070b3692 100644
> --- a/fs/reiserfs/inode.c
> +++ b/fs/reiserfs/inode.c
> @@ -1160,11 +1160,9 @@ int reiserfs_get_block(struct inode *inode, sector_t block,
> return retval;
> }
>
> -static int
> -reiserfs_readpages(struct file *file, struct address_space *mapping,
> - struct list_head *pages, unsigned nr_pages)
> +static void reiserfs_readahead(struct readahead_control *rac)
> {
> - return mpage_readpages(mapping, pages, nr_pages, reiserfs_get_block);
> + mpage_readahead(rac, reiserfs_get_block);
> }
>
> /*
> @@ -3434,7 +3432,7 @@ int reiserfs_setattr(struct dentry *dentry, struct iattr *attr)
> const struct address_space_operations reiserfs_address_space_operations = {
> .writepage = reiserfs_writepage,
> .readpage = reiserfs_readpage,
> - .readpages = reiserfs_readpages,
> + .readahead = reiserfs_readahead,
> .releasepage = reiserfs_releasepage,
> .invalidatepage = reiserfs_invalidatepage,
> .write_begin = reiserfs_write_begin,
> diff --git a/fs/udf/inode.c b/fs/udf/inode.c
> index e875bc5668ee..adaba8e8b326 100644
> --- a/fs/udf/inode.c
> +++ b/fs/udf/inode.c
> @@ -195,10 +195,9 @@ static int udf_readpage(struct file *file, struct page *page)
> return mpage_readpage(page, udf_get_block);
> }
>
> -static int udf_readpages(struct file *file, struct address_space *mapping,
> - struct list_head *pages, unsigned nr_pages)
> +static void udf_readahead(struct readahead_control *rac)
> {
> - return mpage_readpages(mapping, pages, nr_pages, udf_get_block);
> + mpage_readahead(rac, udf_get_block);
> }
>
> static int udf_write_begin(struct file *file, struct address_space *mapping,
> @@ -234,7 +233,7 @@ static sector_t udf_bmap(struct address_space *mapping, sector_t block)
>
> const struct address_space_operations udf_aops = {
> .readpage = udf_readpage,
> - .readpages = udf_readpages,
> + .readahead = udf_readahead,
> .writepage = udf_writepage,
> .writepages = udf_writepages,
> .write_begin = udf_write_begin,
> diff --git a/include/linux/mpage.h b/include/linux/mpage.h
> index 001f1fcf9836..f4f5e90a6844 100644
> --- a/include/linux/mpage.h
> +++ b/include/linux/mpage.h
> @@ -13,9 +13,9 @@
> #ifdef CONFIG_BLOCK
>
> struct writeback_control;
> +struct readahead_control;
>
> -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 *, get_block_t get_block);
> int mpage_readpage(struct page *page, get_block_t get_block);
> int mpage_writepages(struct address_space *mapping,
> struct writeback_control *wbc, get_block_t get_block);
> diff --git a/mm/migrate.c b/mm/migrate.c
> index b1092876e537..a32122095702 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -1020,7 +1020,7 @@ static int __unmap_and_move(struct page *page, struct page *newpage,
> * to the LRU. Later, when the IO completes the pages are
> * marked uptodate and unlocked. However, the queueing
> * could be merging multiple pages for one bio (e.g.
> - * mpage_readpages). If an allocation happens for the
> + * mpage_readahead). If an allocation happens for the
> * second or third page, the process can end up locking
> * the same page twice and deadlocking. Rather than
> * trying to be clever about what pages can be locked,
>