From ad68972acb82c3e8bba316d542ab204984cb1f1c Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Mon, 15 Feb 2016 17:21:31 +1100 Subject: [PATCH] xfs: xfs_cluster_write is redundant xfs_cluster_write() is not necessary now that xfs_vm_writepages() aggregates writepage calls across a single mapping. This means we no longer need to do page lookups in xfs_cluster_write, so writeback only needs to look up th epage cache once per page being written. This also removes a large amount of mostly duplicate code between xfs_do_writepage() and xfs_convert_page(). Signed-off-by: Dave Chinner Reviewed-by: Christoph Hellwig Signed-off-by: Dave Chinner --- fs/xfs/xfs_aops.c | 214 ++-------------------------------------------- 1 file changed, 6 insertions(+), 208 deletions(-) diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c index e0be34125cf0..f75c7c99cb63 100644 --- a/fs/xfs/xfs_aops.c +++ b/fs/xfs/xfs_aops.c @@ -650,179 +650,6 @@ xfs_check_page_type( return false; } -/* - * Allocate & map buffers for page given the extent map. Write it out. - * except for the original page of a writepage, this is called on - * delalloc/unwritten pages only, for the original page it is possible - * that the page has no mapping at all. - */ -STATIC int -xfs_convert_page( - struct inode *inode, - struct page *page, - loff_t tindex, - struct xfs_writepage_ctx *wpc, - struct writeback_control *wbc) -{ - struct buffer_head *bh, *head; - xfs_off_t end_offset; - unsigned long p_offset; - int len, page_dirty; - int count = 0, done = 0, uptodate = 1; - xfs_off_t offset = page_offset(page); - - if (page->index != tindex) - goto fail; - if (!trylock_page(page)) - goto fail; - if (PageWriteback(page)) - goto fail_unlock_page; - if (page->mapping != inode->i_mapping) - goto fail_unlock_page; - if (!xfs_check_page_type(page, wpc->ioend->io_type, false)) - goto fail_unlock_page; - - /* - * page_dirty is initially a count of buffers on the page before - * EOF and is decremented as we move each into a cleanable state. - * - * Derivation: - * - * End offset is the highest offset that this page should represent. - * If we are on the last page, (end_offset & (PAGE_CACHE_SIZE - 1)) - * will evaluate non-zero and be less than PAGE_CACHE_SIZE and - * hence give us the correct page_dirty count. On any other page, - * it will be zero and in that case we need page_dirty to be the - * count of buffers on the page. - */ - end_offset = min_t(unsigned long long, - (xfs_off_t)(page->index + 1) << PAGE_CACHE_SHIFT, - i_size_read(inode)); - - /* - * If the current map does not span the entire page we are about to try - * to write, then give up. The only way we can write a page that spans - * multiple mappings in a single writeback iteration is via the - * xfs_vm_writepage() function. Data integrity writeback requires the - * entire page to be written in a single attempt, otherwise the part of - * the page we don't write here doesn't get written as part of the data - * integrity sync. - * - * For normal writeback, we also don't attempt to write partial pages - * here as it simply means that write_cache_pages() will see it under - * writeback and ignore the page until some point in the future, at - * which time this will be the only page in the file that needs - * writeback. Hence for more optimal IO patterns, we should always - * avoid partial page writeback due to multiple mappings on a page here. - */ - if (!xfs_imap_valid(inode, &wpc->imap, end_offset)) - goto fail_unlock_page; - - len = 1 << inode->i_blkbits; - p_offset = min_t(unsigned long, end_offset & (PAGE_CACHE_SIZE - 1), - PAGE_CACHE_SIZE); - p_offset = p_offset ? roundup(p_offset, len) : PAGE_CACHE_SIZE; - page_dirty = p_offset / len; - - /* - * The moment we find a buffer that doesn't match our current type - * specification or can't be written, abort the loop and start - * writeback. As per the above xfs_imap_valid() check, only - * xfs_vm_writepage() can handle partial page writeback fully - we are - * limited here to the buffers that are contiguous with the current - * ioend, and hence a buffer we can't write breaks that contiguity and - * we have to defer the rest of the IO to xfs_vm_writepage(). - */ - bh = head = page_buffers(page); - do { - if (offset >= end_offset) - break; - if (!buffer_uptodate(bh)) - uptodate = 0; - if (!(PageUptodate(page) || buffer_uptodate(bh))) { - done = 1; - break; - } - - if (buffer_unwritten(bh) || buffer_delay(bh) || - buffer_mapped(bh)) { - if (buffer_unwritten(bh)) - wpc->io_type = XFS_IO_UNWRITTEN; - else if (buffer_delay(bh)) - wpc->io_type = XFS_IO_DELALLOC; - else - wpc->io_type = XFS_IO_OVERWRITE; - - /* - * imap should always be valid because of the above - * partial page end_offset check on the imap. - */ - ASSERT(xfs_imap_valid(inode, &wpc->imap, offset)); - - lock_buffer(bh); - if (wpc->io_type != XFS_IO_OVERWRITE) - xfs_map_at_offset(inode, bh, &wpc->imap, offset); - xfs_add_to_ioend(inode, bh, offset, wpc); - - page_dirty--; - count++; - } else { - done = 1; - break; - } - } while (offset += len, (bh = bh->b_this_page) != head); - - if (uptodate && bh == head) - SetPageUptodate(page); - - if (count) { - if (--wbc->nr_to_write <= 0 && - wbc->sync_mode == WB_SYNC_NONE) - done = 1; - } - xfs_start_page_writeback(page, !page_dirty, count); - - return done; - fail_unlock_page: - unlock_page(page); - fail: - return 1; -} - -/* - * Convert & write out a cluster of pages in the same extent as defined - * by mp and following the start page. - */ -STATIC void -xfs_cluster_write( - struct inode *inode, - pgoff_t tindex, - struct xfs_writepage_ctx *wpc, - struct writeback_control *wbc, - pgoff_t tlast) -{ - struct pagevec pvec; - int done = 0, i; - - pagevec_init(&pvec, 0); - while (!done && tindex <= tlast) { - unsigned len = min_t(pgoff_t, PAGEVEC_SIZE, tlast - tindex + 1); - - if (!pagevec_lookup(&pvec, inode->i_mapping, tindex, len)) - break; - - for (i = 0; i < pagevec_count(&pvec); i++) { - done = xfs_convert_page(inode, pvec.pages[i], tindex++, - wpc, wbc); - if (done) - break; - } - - pagevec_release(&pvec); - cond_resched(); - } -} - STATIC void xfs_vm_invalidatepage( struct page *page, @@ -939,7 +766,7 @@ xfs_do_writepage( struct buffer_head *bh, *head; loff_t offset; __uint64_t end_offset; - pgoff_t end_index, last_index; + pgoff_t end_index; ssize_t len; int err, uptodate = 1; int count = 0; @@ -969,12 +796,9 @@ xfs_do_writepage( if (WARN_ON_ONCE(current->flags & PF_FSTRANS)) goto redirty; - /* Is this page beyond the end of the file? */ - offset = i_size_read(inode); - end_index = offset >> PAGE_CACHE_SHIFT; - last_index = (offset - 1) >> PAGE_CACHE_SHIFT; - /* + * Is this page beyond the end of the file? + * * The page index is less than the end_index, adjust the end_offset * to the highest offset that this page should represent. * ----------------------------------------------------- @@ -985,6 +809,8 @@ xfs_do_writepage( * | desired writeback range | see else | * ---------------------------------^------------------| */ + offset = i_size_read(inode); + end_index = offset >> PAGE_CACHE_SHIFT; if (page->index < end_index) end_offset = (xfs_off_t)(page->index + 1) << PAGE_CACHE_SHIFT; else { @@ -1113,35 +939,7 @@ xfs_do_writepage( xfs_start_page_writeback(page, 1, count); - /* if there is no IO to be submitted for this page, we are done */ - if (!count) - return 0; - - ASSERT(wpc->iohead); - ASSERT(err == 0); - - /* - * Any errors from this point onwards need tobe reported through the IO - * completion path as we have marked the initial page as under writeback - * and unlocked it. - */ - if (wpc->imap_valid) { - xfs_off_t end_index; - - end_index = wpc->imap.br_startoff + wpc->imap.br_blockcount; - - /* to bytes */ - end_index <<= inode->i_blkbits; - - /* to pages */ - end_index = (end_index - 1) >> PAGE_CACHE_SHIFT; - - /* check against file size */ - if (end_index > last_index) - end_index = last_index; - - xfs_cluster_write(inode, page->index + 1, wpc, wbc, end_index); - } + ASSERT(wpc->iohead || !count); return 0; error: -- 2.39.5