From: "Kirill A. Shutemov" Subject: [PATCHv4 35/43] ext4: make ext4_block_write_begin() aware about huge pages Date: Tue, 25 Oct 2016 03:13:34 +0300 Message-ID: <20161025001342.76126-36-kirill.shutemov@linux.intel.com> References: <20161025001342.76126-1-kirill.shutemov@linux.intel.com> Cc: Alexander Viro , Hugh Dickins , Andrea Arcangeli , Dave Hansen , Vlastimil Babka , Matthew Wilcox , Ross Zwisler , linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-block@vger.kernel.org, "Kirill A. Shutemov" To: "Theodore Ts'o" , Andreas Dilger , Jan Kara , Andrew Morton Return-path: In-Reply-To: <20161025001342.76126-1-kirill.shutemov@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org It simply matches changes to __block_write_begin_int(). Signed-off-by: Kirill A. Shutemov --- fs/ext4/inode.c | 35 +++++++++++++++++++++-------------- 1 file changed, 21 insertions(+), 14 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index c1728d2bf47b..1eae6801846c 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -1087,9 +1087,8 @@ int do_journal_get_write_access(handle_t *handle, static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len, get_block_t *get_block) { - unsigned from = pos & (PAGE_SIZE - 1); - unsigned to = from + len; - struct inode *inode = page->mapping->host; + unsigned from, to; + struct inode *inode = page_mapping(page)->host; unsigned block_start, block_end; sector_t block; int err = 0; @@ -1097,10 +1096,14 @@ static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len, unsigned bbits; struct buffer_head *bh, *head, *wait[2], **wait_bh = wait; bool decrypt = false; + bool uptodate = PageUptodate(page); + page = compound_head(page); + from = pos & ~hpage_mask(page); + to = from + len; BUG_ON(!PageLocked(page)); - BUG_ON(from > PAGE_SIZE); - BUG_ON(to > PAGE_SIZE); + BUG_ON(from > hpage_size(page)); + BUG_ON(to > hpage_size(page)); BUG_ON(from > to); if (!page_has_buffers(page)) @@ -1113,10 +1116,8 @@ static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len, block++, block_start = block_end, bh = bh->b_this_page) { block_end = block_start + blocksize; if (block_end <= from || block_start >= to) { - if (PageUptodate(page)) { - if (!buffer_uptodate(bh)) - set_buffer_uptodate(bh); - } + if (uptodate && !buffer_uptodate(bh)) + set_buffer_uptodate(bh); continue; } if (buffer_new(bh)) @@ -1129,19 +1130,25 @@ static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len, if (buffer_new(bh)) { unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr); - if (PageUptodate(page)) { + if (uptodate) { clear_buffer_new(bh); set_buffer_uptodate(bh); mark_buffer_dirty(bh); continue; } - if (block_end > to || block_start < from) - zero_user_segments(page, to, block_end, - block_start, from); + if (block_end > to || block_start < from) { + BUG_ON(to - from > PAGE_SIZE); + zero_user_segments(page + + block_start / PAGE_SIZE, + to % PAGE_SIZE, + (block_start % PAGE_SIZE) + blocksize, + block_start % PAGE_SIZE, + from % PAGE_SIZE); + } continue; } } - if (PageUptodate(page)) { + if (uptodate) { if (!buffer_uptodate(bh)) set_buffer_uptodate(bh); continue; -- 2.9.3