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 <ross.zwisler@xxxxxxxxxxxxxxx>
---
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
--
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