From f132ab7d3ab03c5bae28d31fb80ba77c4da05500 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Fri, 29 Apr 2022 11:47:39 -0400 Subject: fs: Convert mpage_readpage to mpage_read_folio mpage_readpage still works in terms of pages, and has not been audited for correctness with large folios, so include an assertion that the filesystem is not passing it large folios. Convert all the filesystems to call mpage_read_folio() instead of mpage_readpage(). Signed-off-by: Matthew Wilcox (Oracle) --- include/linux/mpage.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/mpage.h') diff --git a/include/linux/mpage.h b/include/linux/mpage.h index f4f5e90a6844..43986f7ec4dd 100644 --- a/include/linux/mpage.h +++ b/include/linux/mpage.h @@ -16,7 +16,7 @@ struct writeback_control; struct readahead_control; void mpage_readahead(struct readahead_control *, get_block_t get_block); -int mpage_readpage(struct page *page, get_block_t get_block); +int mpage_read_folio(struct folio *folio, get_block_t get_block); int mpage_writepages(struct address_space *mapping, struct writeback_control *wbc, get_block_t get_block); int mpage_writepage(struct page *page, get_block_t *get_block, -- cgit v1.2.3 From cc9cf350d100f4c336edb228cbd078003430cfe7 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 13 Jun 2022 07:37:13 +0200 Subject: fs: remove the nobh helpers All callers are gone, so remove the now dead code. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Signed-off-by: Matthew Wilcox (Oracle) --- fs/buffer.c | 324 -------------------------------------------- fs/mpage.c | 25 +--- include/linux/buffer_head.h | 8 -- include/linux/mpage.h | 2 - 4 files changed, 1 insertion(+), 358 deletions(-) (limited to 'include/linux/mpage.h') diff --git a/fs/buffer.c b/fs/buffer.c index ce9844d7c10f..5717d1881d2f 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -2537,330 +2537,6 @@ out_unlock: } EXPORT_SYMBOL(block_page_mkwrite); -/* - * nobh_write_begin()'s prereads are special: the buffer_heads are freed - * immediately, while under the page lock. So it needs a special end_io - * handler which does not touch the bh after unlocking it. - */ -static void end_buffer_read_nobh(struct buffer_head *bh, int uptodate) -{ - __end_buffer_read_notouch(bh, uptodate); -} - -/* - * Attach the singly-linked list of buffers created by nobh_write_begin, to - * the page (converting it to circular linked list and taking care of page - * dirty races). - */ -static void attach_nobh_buffers(struct page *page, struct buffer_head *head) -{ - struct buffer_head *bh; - - BUG_ON(!PageLocked(page)); - - spin_lock(&page->mapping->private_lock); - bh = head; - do { - if (PageDirty(page)) - set_buffer_dirty(bh); - if (!bh->b_this_page) - bh->b_this_page = head; - bh = bh->b_this_page; - } while (bh != head); - attach_page_private(page, head); - spin_unlock(&page->mapping->private_lock); -} - -/* - * On entry, the page is fully not uptodate. - * On exit the page is fully uptodate in the areas outside (from,to) - * The filesystem needs to handle block truncation upon failure. - */ -int nobh_write_begin(struct address_space *mapping, loff_t pos, unsigned len, - struct page **pagep, void **fsdata, - get_block_t *get_block) -{ - struct inode *inode = mapping->host; - const unsigned blkbits = inode->i_blkbits; - const unsigned blocksize = 1 << blkbits; - struct buffer_head *head, *bh; - struct page *page; - pgoff_t index; - unsigned from, to; - unsigned block_in_page; - unsigned block_start, block_end; - sector_t block_in_file; - int nr_reads = 0; - int ret = 0; - int is_mapped_to_disk = 1; - - index = pos >> PAGE_SHIFT; - from = pos & (PAGE_SIZE - 1); - to = from + len; - - page = grab_cache_page_write_begin(mapping, index); - if (!page) - return -ENOMEM; - *pagep = page; - *fsdata = NULL; - - if (page_has_buffers(page)) { - ret = __block_write_begin(page, pos, len, get_block); - if (unlikely(ret)) - goto out_release; - return ret; - } - - if (PageMappedToDisk(page)) - return 0; - - /* - * Allocate buffers so that we can keep track of state, and potentially - * attach them to the page if an error occurs. In the common case of - * no error, they will just be freed again without ever being attached - * to the page (which is all OK, because we're under the page lock). - * - * Be careful: the buffer linked list is a NULL terminated one, rather - * than the circular one we're used to. - */ - head = alloc_page_buffers(page, blocksize, false); - if (!head) { - ret = -ENOMEM; - goto out_release; - } - - block_in_file = (sector_t)page->index << (PAGE_SHIFT - blkbits); - - /* - * We loop across all blocks in the page, whether or not they are - * part of the affected region. This is so we can discover if the - * page is fully mapped-to-disk. - */ - for (block_start = 0, block_in_page = 0, bh = head; - block_start < PAGE_SIZE; - block_in_page++, block_start += blocksize, bh = bh->b_this_page) { - int create; - - block_end = block_start + blocksize; - bh->b_state = 0; - create = 1; - if (block_start >= to) - create = 0; - ret = get_block(inode, block_in_file + block_in_page, - bh, create); - if (ret) - goto failed; - if (!buffer_mapped(bh)) - is_mapped_to_disk = 0; - if (buffer_new(bh)) - clean_bdev_bh_alias(bh); - if (PageUptodate(page)) { - set_buffer_uptodate(bh); - continue; - } - if (buffer_new(bh) || !buffer_mapped(bh)) { - zero_user_segments(page, block_start, from, - to, block_end); - continue; - } - if (buffer_uptodate(bh)) - continue; /* reiserfs does this */ - if (block_start < from || block_end > to) { - lock_buffer(bh); - bh->b_end_io = end_buffer_read_nobh; - submit_bh(REQ_OP_READ, 0, bh); - nr_reads++; - } - } - - if (nr_reads) { - /* - * The page is locked, so these buffers are protected from - * any VM or truncate activity. Hence we don't need to care - * for the buffer_head refcounts. - */ - for (bh = head; bh; bh = bh->b_this_page) { - wait_on_buffer(bh); - if (!buffer_uptodate(bh)) - ret = -EIO; - } - if (ret) - goto failed; - } - - if (is_mapped_to_disk) - SetPageMappedToDisk(page); - - *fsdata = head; /* to be released by nobh_write_end */ - - return 0; - -failed: - BUG_ON(!ret); - /* - * Error recovery is a bit difficult. We need to zero out blocks that - * were newly allocated, and dirty them to ensure they get written out. - * Buffers need to be attached to the page at this point, otherwise - * the handling of potential IO errors during writeout would be hard - * (could try doing synchronous writeout, but what if that fails too?) - */ - attach_nobh_buffers(page, head); - page_zero_new_buffers(page, from, to); - -out_release: - unlock_page(page); - put_page(page); - *pagep = NULL; - - return ret; -} -EXPORT_SYMBOL(nobh_write_begin); - -int nobh_write_end(struct file *file, struct address_space *mapping, - loff_t pos, unsigned len, unsigned copied, - struct page *page, void *fsdata) -{ - struct inode *inode = page->mapping->host; - struct buffer_head *head = fsdata; - struct buffer_head *bh; - BUG_ON(fsdata != NULL && page_has_buffers(page)); - - if (unlikely(copied < len) && head) - attach_nobh_buffers(page, head); - if (page_has_buffers(page)) - return generic_write_end(file, mapping, pos, len, - copied, page, fsdata); - - SetPageUptodate(page); - set_page_dirty(page); - if (pos+copied > inode->i_size) { - i_size_write(inode, pos+copied); - mark_inode_dirty(inode); - } - - unlock_page(page); - put_page(page); - - while (head) { - bh = head; - head = head->b_this_page; - free_buffer_head(bh); - } - - return copied; -} -EXPORT_SYMBOL(nobh_write_end); - -/* - * nobh_writepage() - based on block_full_write_page() except - * that it tries to operate without attaching bufferheads to - * the page. - */ -int nobh_writepage(struct page *page, get_block_t *get_block, - struct writeback_control *wbc) -{ - struct inode * const inode = page->mapping->host; - loff_t i_size = i_size_read(inode); - const pgoff_t end_index = i_size >> PAGE_SHIFT; - unsigned offset; - int ret; - - /* Is the page fully inside i_size? */ - if (page->index < end_index) - goto out; - - /* Is the page fully outside i_size? (truncate in progress) */ - offset = i_size & (PAGE_SIZE-1); - if (page->index >= end_index+1 || !offset) { - unlock_page(page); - return 0; /* don't care */ - } - - /* - * The page straddles i_size. It must be zeroed out on each and every - * writepage invocation because it may be mmapped. "A file is mapped - * in multiples of the page size. For a file that is not a multiple of - * the page size, the remaining memory is zeroed when mapped, and - * writes to that region are not written out to the file." - */ - zero_user_segment(page, offset, PAGE_SIZE); -out: - ret = mpage_writepage(page, get_block, wbc); - if (ret == -EAGAIN) - ret = __block_write_full_page(inode, page, get_block, wbc, - end_buffer_async_write); - return ret; -} -EXPORT_SYMBOL(nobh_writepage); - -int nobh_truncate_page(struct address_space *mapping, - loff_t from, get_block_t *get_block) -{ - pgoff_t index = from >> PAGE_SHIFT; - struct inode *inode = mapping->host; - unsigned blocksize = i_blocksize(inode); - struct folio *folio; - struct buffer_head map_bh; - size_t offset; - sector_t iblock; - int err; - - /* Block boundary? Nothing to do */ - if (!(from & (blocksize - 1))) - return 0; - - folio = __filemap_get_folio(mapping, index, FGP_LOCK | FGP_CREAT, - mapping_gfp_mask(mapping)); - err = -ENOMEM; - if (!folio) - goto out; - - if (folio_buffers(folio)) - goto has_buffers; - - iblock = from >> inode->i_blkbits; - map_bh.b_size = blocksize; - map_bh.b_state = 0; - err = get_block(inode, iblock, &map_bh, 0); - if (err) - goto unlock; - /* unmapped? It's a hole - nothing to do */ - if (!buffer_mapped(&map_bh)) - goto unlock; - - /* Ok, it's mapped. Make sure it's up-to-date */ - if (!folio_test_uptodate(folio)) { - err = mapping->a_ops->read_folio(NULL, folio); - if (err) { - folio_put(folio); - goto out; - } - folio_lock(folio); - if (!folio_test_uptodate(folio)) { - err = -EIO; - goto unlock; - } - if (folio_buffers(folio)) - goto has_buffers; - } - offset = offset_in_folio(folio, from); - folio_zero_segment(folio, offset, round_up(offset, blocksize)); - folio_mark_dirty(folio); - err = 0; - -unlock: - folio_unlock(folio); - folio_put(folio); -out: - return err; - -has_buffers: - folio_unlock(folio); - folio_put(folio); - return block_truncate_page(mapping, from, get_block); -} -EXPORT_SYMBOL(nobh_truncate_page); - int block_truncate_page(struct address_space *mapping, loff_t from, get_block_t *get_block) { diff --git a/fs/mpage.c b/fs/mpage.c index 681a4b9a36e3..b7e0b7fbb41f 100644 --- a/fs/mpage.c +++ b/fs/mpage.c @@ -404,7 +404,6 @@ struct mpage_data { struct bio *bio; sector_t last_block_in_bio; get_block_t *get_block; - unsigned use_writepage; }; /* @@ -624,15 +623,10 @@ confused: if (bio) bio = mpage_bio_submit(bio); - if (mpd->use_writepage) { - ret = mapping->a_ops->writepage(page, wbc); - } else { - ret = -EAGAIN; - goto out; - } /* * The caller has a ref on the inode, so *mapping is stable */ + ret = mapping->a_ops->writepage(page, wbc); mapping_set_error(mapping, ret); out: mpd->bio = bio; @@ -674,7 +668,6 @@ mpage_writepages(struct address_space *mapping, .bio = NULL, .last_block_in_bio = 0, .get_block = get_block, - .use_writepage = 1, }; ret = write_cache_pages(mapping, wbc, __mpage_writepage, &mpd); @@ -685,19 +678,3 @@ mpage_writepages(struct address_space *mapping, return ret; } EXPORT_SYMBOL(mpage_writepages); - -int mpage_writepage(struct page *page, get_block_t get_block, - struct writeback_control *wbc) -{ - struct mpage_data mpd = { - .bio = NULL, - .last_block_in_bio = 0, - .get_block = get_block, - .use_writepage = 0, - }; - int ret = __mpage_writepage(page, wbc, &mpd); - if (mpd.bio) - mpage_bio_submit(mpd.bio); - return ret; -} -EXPORT_SYMBOL(mpage_writepage); diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h index b0366c89d6a4..61afb81cfdae 100644 --- a/include/linux/buffer_head.h +++ b/include/linux/buffer_head.h @@ -258,14 +258,6 @@ static inline vm_fault_t block_page_mkwrite_return(int err) } sector_t generic_block_bmap(struct address_space *, sector_t, get_block_t *); int block_truncate_page(struct address_space *, loff_t, get_block_t *); -int nobh_write_begin(struct address_space *, loff_t, unsigned len, - struct page **, void **, get_block_t*); -int nobh_write_end(struct file *, struct address_space *, - loff_t, unsigned, unsigned, - struct page *, void *); -int nobh_truncate_page(struct address_space *, loff_t, get_block_t *); -int nobh_writepage(struct page *page, get_block_t *get_block, - struct writeback_control *wbc); #ifdef CONFIG_MIGRATION extern int buffer_migrate_folio(struct address_space *, diff --git a/include/linux/mpage.h b/include/linux/mpage.h index 43986f7ec4dd..1bdc39daac0a 100644 --- a/include/linux/mpage.h +++ b/include/linux/mpage.h @@ -19,7 +19,5 @@ void mpage_readahead(struct readahead_control *, get_block_t get_block); int mpage_read_folio(struct folio *folio, get_block_t get_block); int mpage_writepages(struct address_space *mapping, struct writeback_control *wbc, get_block_t get_block); -int mpage_writepage(struct page *page, get_block_t *get_block, - struct writeback_control *wbc); #endif -- cgit v1.2.3