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authorMikulas Patocka <mpatocka@redhat.com>2020-08-24 18:09:47 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-09-09 20:04:31 +0300
commit154096e9966123f198cfc2f959bc559c562fc6b7 (patch)
treee3ca67c42d511ca6832b426fe6a33ecada2a0f8d /drivers/md
parenta8bb7740aa313994bfa4c21cba399f65985a8a35 (diff)
downloadlinux-154096e9966123f198cfc2f959bc559c562fc6b7.tar.xz
dm writecache: handle DAX to partitions on persistent memory correctly
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>
Diffstat (limited to 'drivers/md')
-rw-r--r--drivers/md/dm-writecache.c12
1 files changed, 10 insertions, 2 deletions
diff --git a/drivers/md/dm-writecache.c b/drivers/md/dm-writecache.c
index cc028353f9d5..776aaf5951e4 100644
--- a/drivers/md/dm-writecache.c
+++ b/drivers/md/dm-writecache.c
@@ -226,6 +226,7 @@ static int persistent_memory_claim(struct dm_writecache *wc)
pfn_t pfn;
int id;
struct page **pages;
+ sector_t offset;
wc->memory_vmapped = false;
@@ -244,9 +245,16 @@ static int persistent_memory_claim(struct dm_writecache *wc)
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(struct dm_writecache *wc)
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;