From: Ross Zwisler Subject: [PATCH 1/2] dm log writes: Add support for inline data buffers Date: Thu, 19 Oct 2017 23:24:03 -0600 Message-ID: <20171020052404.13762-1-ross.zwisler@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: linux-xfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Jan Kara , Mike Snitzer , linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org, Dave Chinner , linux-raid-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, dm-devel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, Christoph Hellwig , linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-ext4-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Shaohua Li , Alasdair Kergon To: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Josef Bacik Return-path: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-nvdimm-bounces-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org Sender: "Linux-nvdimm" List-Id: linux-ext4.vger.kernel.org Currently dm-log-writes supports writing filesystem data via BIOs, and writing internal metadata from a flat buffer via write_metadata(). For DAX writes, though, we won't have a BIO, but will instead have an iterator that we'll want to use to fill a flat data buffer. So, create write_inline_data() which allows us to write filesystem data using a flat buffer as a source, and wire it up in log_one_block(). Signed-off-by: Ross Zwisler --- drivers/md/dm-log-writes.c | 90 +++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 86 insertions(+), 4 deletions(-) diff --git a/drivers/md/dm-log-writes.c b/drivers/md/dm-log-writes.c index 8b80a9c..c65f9d1 100644 --- a/drivers/md/dm-log-writes.c +++ b/drivers/md/dm-log-writes.c @@ -246,27 +246,109 @@ static int write_metadata(struct log_writes_c *lc, void *entry, return -1; } +static int write_inline_data(struct log_writes_c *lc, void *entry, + size_t entrylen, void *data, size_t datalen, + sector_t sector) +{ + int num_pages, bio_pages, pg_datalen, pg_sectorlen, i; + struct page *page; + struct bio *bio; + size_t ret; + void *ptr; + + while (datalen) { + num_pages = ALIGN(datalen, PAGE_SIZE) >> PAGE_SHIFT; + bio_pages = min(num_pages, BIO_MAX_PAGES); + + atomic_inc(&lc->io_blocks); + + bio = bio_alloc(GFP_KERNEL, bio_pages); + if (!bio) { + DMERR("Couldn't alloc inline data bio"); + goto error; + } + + bio->bi_iter.bi_size = 0; + bio->bi_iter.bi_sector = sector; + bio_set_dev(bio, lc->logdev->bdev); + bio->bi_end_io = log_end_io; + bio->bi_private = lc; + bio_set_op_attrs(bio, REQ_OP_WRITE, 0); + + for (i = 0; i < bio_pages; i++) { + pg_datalen = min(datalen, PAGE_SIZE); + pg_sectorlen = ALIGN(pg_datalen, lc->sectorsize); + + page = alloc_page(GFP_KERNEL); + if (!page) { + DMERR("Couldn't alloc inline data page"); + goto error_bio; + } + + ptr = kmap_atomic(page); + memcpy(ptr, data, pg_datalen); + if (pg_sectorlen > pg_datalen) + memset(ptr + pg_datalen, 0, + pg_sectorlen - pg_datalen); + kunmap_atomic(ptr); + + ret = bio_add_page(bio, page, pg_sectorlen, 0); + if (ret != pg_sectorlen) { + DMERR("Couldn't add page of inline data"); + __free_page(page); + goto error_bio; + } + + datalen -= pg_datalen; + data += pg_datalen; + } + submit_bio(bio); + + sector += bio_pages * PAGE_SECTORS; + } + return 0; +error_bio: + bio_free_pages(bio); + bio_put(bio); +error: + put_io_block(lc); + return -1; +} + static int log_one_block(struct log_writes_c *lc, struct pending_block *block, sector_t sector) { struct bio *bio; struct log_write_entry entry; - size_t ret; + size_t metadlen, ret; int i; entry.sector = cpu_to_le64(block->sector); entry.nr_sectors = cpu_to_le64(block->nr_sectors); entry.flags = cpu_to_le64(block->flags); entry.data_len = cpu_to_le64(block->datalen); - if (write_metadata(lc, &entry, sizeof(entry), block->data, - block->datalen, sector)) { + + metadlen = (block->flags & LOG_MARK_FLAG) ? block->datalen : 0; + if (write_metadata(lc, &entry, sizeof(entry), block->data, metadlen, + sector)) { free_pending_block(lc, block); return -1; } + sector += dev_to_bio_sectors(lc, 1); + + if (block->datalen && metadlen == 0) { + if (write_inline_data(lc, &entry, sizeof(entry), block->data, + block->datalen, sector)) { + free_pending_block(lc, block); + return -1; + } + /* we don't support both inline data & bio data */ + goto out; + } + if (!block->vec_cnt) goto out; - sector += dev_to_bio_sectors(lc, 1); atomic_inc(&lc->io_blocks); bio = bio_alloc(GFP_KERNEL, min(block->vec_cnt, BIO_MAX_PAGES)); -- 2.9.5