From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Chandan Rajendra Subject: [PATCH RESEND V5 5/7] ext4: Wire up ext4_readpage[s] to use mpage_readpage[s] Date: Tue, 10 Sep 2019 21:21:13 +0530 Message-Id: <20190910155115.28550-6-chandan@linux.ibm.com> In-Reply-To: <20190910155115.28550-1-chandan@linux.ibm.com> References: <20190910155115.28550-1-chandan@linux.ibm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit To: viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-fscrypt@vger.kernel.org Cc: Chandan Rajendra , tytso@mit.edu, adilger.kernel@dilger.ca, ebiggers@kernel.org, hch@infradead.org, chandanrlinux@gmail.com List-ID: Now that do_mpage_readpage() is "post read process" aware, this commit gets ext4_readpage[s] to use mpage_readpage[s] and deletes ext4's readpage.c since the associated functionality is not required anymore. --- fs/ext4/Makefile | 2 +- fs/ext4/inode.c | 5 +- fs/ext4/readpage.c | 295 --------------------------------------------- 3 files changed, 3 insertions(+), 299 deletions(-) delete mode 100644 fs/ext4/readpage.c diff --git a/fs/ext4/Makefile b/fs/ext4/Makefile index 8fdfcd3c3e04..7c38803a808d 100644 --- a/fs/ext4/Makefile +++ b/fs/ext4/Makefile @@ -8,7 +8,7 @@ obj-$(CONFIG_EXT4_FS) += ext4.o ext4-y := balloc.o bitmap.o block_validity.o dir.o ext4_jbd2.o extents.o \ extents_status.o file.o fsmap.o fsync.o hash.o ialloc.o \ indirect.o inline.o inode.o ioctl.o mballoc.o migrate.o \ - mmp.o move_extent.o namei.o page-io.o readpage.o resize.o \ + mmp.o move_extent.o namei.o page-io.o resize.o \ super.o symlink.o sysfs.o xattr.o xattr_trusted.o xattr_user.o ext4-$(CONFIG_EXT4_FS_POSIX_ACL) += acl.o diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 58597db621e1..a1136faed9d3 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3361,8 +3361,7 @@ 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 mpage_readpage(page, ext4_get_block); return ret; } @@ -3377,7 +3376,7 @@ ext4_readpages(struct file *file, struct address_space *mapping, if (ext4_has_inline_data(inode)) return 0; - return ext4_mpage_readpages(mapping, pages, NULL, nr_pages, true); + return mpage_readpages(mapping, pages, nr_pages, ext4_get_block); } static void ext4_invalidatepage(struct page *page, unsigned int offset, diff --git a/fs/ext4/readpage.c b/fs/ext4/readpage.c deleted file mode 100644 index 75cef6af6080..000000000000 --- a/fs/ext4/readpage.c +++ /dev/null @@ -1,295 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * linux/fs/ext4/readpage.c - * - * Copyright (C) 2002, Linus Torvalds. - * Copyright (C) 2015, Google, Inc. - * - * 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 - * 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. - * - * This will allow us to attach a callback function to support ext4 - * encryption. - * - * If anything unusual happens, such as: - * - * - encountering a page which has buffers - * - encountering a page which has a non-hole after a hole - * - encountering a page with non-contiguous blocks - * - * then this code just gives up and calls the buffer_head-based read function. - * It does handle a page which has holes at the end - that is a common case: - * the end-of-file on blocksize < PAGE_SIZE setups. - * - */ - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#include "ext4.h" - -static inline bool ext4_bio_encrypted(struct bio *bio) -{ -#ifdef CONFIG_FS_ENCRYPTION - return unlikely(bio->bi_private != NULL); -#else - return false; -#endif -} - -/* - * I/O completion handler for multipage BIOs. - * - * The mpage code never puts partial pages into a BIO (except for end-of-file). - * If a page does not map to a contiguous run of blocks then it simply falls - * back to block_read_full_page(). - * - * Why is this? If a page's completion depends on a number of different BIOs - * which can complete in any order (or at the same time) then determining the - * status of that page is hard. See end_buffer_async_read() for the details. - * There is no point in duplicating all that complexity. - */ -static void mpage_end_io(struct bio *bio) -{ - struct bio_vec *bv; - int i; - struct bvec_iter_all iter_all; - - if (ext4_bio_encrypted(bio)) { - if (bio->bi_status) { - fscrypt_release_ctx(bio->bi_private); - } else { - fscrypt_enqueue_decrypt_bio(bio->bi_private, bio); - return; - } - } - bio_for_each_segment_all(bv, bio, i, iter_all) { - struct page *page = bv->bv_page; - - if (!bio->bi_status) { - SetPageUptodate(page); - } else { - ClearPageUptodate(page); - SetPageError(page); - } - unlock_page(page); - } - - bio_put(bio); -} - -int ext4_mpage_readpages(struct address_space *mapping, - struct list_head *pages, struct page *page, - unsigned nr_pages, bool is_readahead) -{ - struct bio *bio = NULL; - sector_t last_block_in_bio = 0; - - struct inode *inode = mapping->host; - const unsigned blkbits = inode->i_blkbits; - const unsigned blocks_per_page = PAGE_SIZE >> blkbits; - const unsigned blocksize = 1 << blkbits; - sector_t block_in_file; - sector_t last_block; - sector_t last_block_in_file; - sector_t blocks[MAX_BUF_PER_PAGE]; - unsigned page_block; - struct block_device *bdev = inode->i_sb->s_bdev; - int length; - unsigned relative_block = 0; - struct ext4_map_blocks map; - - map.m_pblk = 0; - map.m_lblk = 0; - map.m_len = 0; - map.m_flags = 0; - - for (; nr_pages; nr_pages--) { - int fully_mapped = 1; - unsigned first_hole = blocks_per_page; - - prefetchw(&page->flags); - if (pages) { - page = lru_to_page(pages); - 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)) - goto confused; - - block_in_file = (sector_t)page->index << (PAGE_SHIFT - blkbits); - last_block = block_in_file + nr_pages * blocks_per_page; - last_block_in_file = (i_size_read(inode) + blocksize - 1) >> blkbits; - if (last_block > last_block_in_file) - last_block = last_block_in_file; - page_block = 0; - - /* - * Map blocks using the previous result first. - */ - if ((map.m_flags & EXT4_MAP_MAPPED) && - block_in_file > map.m_lblk && - block_in_file < (map.m_lblk + map.m_len)) { - unsigned map_offset = block_in_file - map.m_lblk; - unsigned last = map.m_len - map_offset; - - for (relative_block = 0; ; relative_block++) { - if (relative_block == last) { - /* needed? */ - map.m_flags &= ~EXT4_MAP_MAPPED; - break; - } - if (page_block == blocks_per_page) - break; - blocks[page_block] = map.m_pblk + map_offset + - relative_block; - page_block++; - block_in_file++; - } - } - - /* - * Then do more ext4_map_blocks() calls until we are - * done with this page. - */ - while (page_block < blocks_per_page) { - if (block_in_file < last_block) { - map.m_lblk = block_in_file; - map.m_len = last_block - block_in_file; - - if (ext4_map_blocks(NULL, inode, &map, 0) < 0) { - set_error_page: - SetPageError(page); - zero_user_segment(page, 0, - PAGE_SIZE); - unlock_page(page); - goto next_page; - } - } - if ((map.m_flags & EXT4_MAP_MAPPED) == 0) { - fully_mapped = 0; - if (first_hole == blocks_per_page) - first_hole = page_block; - page_block++; - block_in_file++; - continue; - } - if (first_hole != blocks_per_page) - goto confused; /* hole -> non-hole */ - - /* Contiguous blocks? */ - if (page_block && blocks[page_block-1] != map.m_pblk-1) - goto confused; - for (relative_block = 0; ; relative_block++) { - if (relative_block == map.m_len) { - /* needed? */ - map.m_flags &= ~EXT4_MAP_MAPPED; - break; - } else if (page_block == blocks_per_page) - break; - blocks[page_block] = map.m_pblk+relative_block; - page_block++; - block_in_file++; - } - } - if (first_hole != blocks_per_page) { - zero_user_segment(page, first_hole << blkbits, - PAGE_SIZE); - if (first_hole == 0) { - SetPageUptodate(page); - unlock_page(page); - goto next_page; - } - } else if (fully_mapped) { - SetPageMappedToDisk(page); - } - if (fully_mapped && blocks_per_page == 1 && - !PageUptodate(page) && cleancache_get_page(page) == 0) { - SetPageUptodate(page); - goto confused; - } - - /* - * This page will go to BIO. Do we need to send this - * BIO off first? - */ - if (bio && (last_block_in_bio != blocks[0] - 1)) { - submit_and_realloc: - submit_bio(bio); - bio = NULL; - } - if (bio == NULL) { - struct fscrypt_ctx *ctx = NULL; - - if (IS_ENCRYPTED(inode) && S_ISREG(inode->i_mode)) { - ctx = fscrypt_get_ctx(GFP_NOFS); - if (IS_ERR(ctx)) - goto set_error_page; - } - bio = bio_alloc(GFP_KERNEL, - min_t(int, nr_pages, BIO_MAX_PAGES)); - if (!bio) { - if (ctx) - fscrypt_release_ctx(ctx); - goto set_error_page; - } - bio_set_dev(bio, bdev); - bio->bi_iter.bi_sector = blocks[0] << (blkbits - 9); - bio->bi_end_io = mpage_end_io; - bio->bi_private = ctx; - bio_set_op_attrs(bio, REQ_OP_READ, - is_readahead ? REQ_RAHEAD : 0); - } - - length = first_hole << blkbits; - if (bio_add_page(bio, page, length, 0) < length) - goto submit_and_realloc; - - if (((map.m_flags & EXT4_MAP_BOUNDARY) && - (relative_block == map.m_len)) || - (first_hole != blocks_per_page)) { - submit_bio(bio); - bio = NULL; - } else - last_block_in_bio = blocks[blocks_per_page - 1]; - goto next_page; - confused: - if (bio) { - submit_bio(bio); - bio = NULL; - } - if (!PageUptodate(page)) - block_read_full_page(page, ext4_get_block); - else - unlock_page(page); - next_page: - if (pages) - put_page(page); - } - BUG_ON(pages && !list_empty(pages)); - if (bio) - submit_bio(bio); - return 0; -} -- 2.19.1