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dm log writes: add support for inline data buffers 

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@linux.intel.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
hifive-unleashed-5.1
Ross Zwisler 2017-10-19 23:24:03 -06:00 committed by Mike Snitzer
parent 693b960ea8
commit e5a20660a1
1 changed files with 84 additions and 3 deletions
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87
drivers/md/dm-log-writes.c
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@ -246,27 +246,108 @@ error:
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_t(int, 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 metadatalen, 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);
metadatalen = (block->flags & LOG_MARK_FLAG) ? block->datalen : 0;
if (write_metadata(lc, &entry, sizeof(entry), block->data,
block->datalen, sector)) {
metadatalen, sector)) {
free_pending_block(lc, block);
return -1;
}
sector += dev_to_bio_sectors(lc, 1);
if (block->datalen && metadatalen == 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));