From: Mikulas Patocka mpatocka@redhat.com
commit f9e040efcc28309e5c592f7e79085a9a52e31f58 upstream.
The function dax_direct_access doesn't take partitions into account, it always maps pages from the beginning of the device. Therefore, persistent_memory_claim() must get the partition offset using get_start_sect() and add it to the page offsets passed to dax_direct_access().
Signed-off-by: Mikulas Patocka mpatocka@redhat.com Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # 4.18+ Signed-off-by: Mike Snitzer snitzer@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/md/dm-writecache.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)
--- a/drivers/md/dm-writecache.c +++ b/drivers/md/dm-writecache.c @@ -226,6 +226,7 @@ static int persistent_memory_claim(struc pfn_t pfn; int id; struct page **pages; + sector_t offset;
wc->memory_vmapped = false;
@@ -244,9 +245,16 @@ static int persistent_memory_claim(struc goto err1; }
+ offset = get_start_sect(wc->ssd_dev->bdev); + if (offset & (PAGE_SIZE / 512 - 1)) { + r = -EINVAL; + goto err1; + } + offset >>= PAGE_SHIFT - 9; + id = dax_read_lock();
- da = dax_direct_access(wc->ssd_dev->dax_dev, 0, p, &wc->memory_map, &pfn); + da = dax_direct_access(wc->ssd_dev->dax_dev, offset, p, &wc->memory_map, &pfn); if (da < 0) { wc->memory_map = NULL; r = da; @@ -268,7 +276,7 @@ static int persistent_memory_claim(struc i = 0; do { long daa; - daa = dax_direct_access(wc->ssd_dev->dax_dev, i, p - i, + daa = dax_direct_access(wc->ssd_dev->dax_dev, offset + i, p - i, NULL, &pfn); if (daa <= 0) { r = daa ? daa : -EINVAL;