@@ -47,7 +47,20 @@ struct pmem_device {
static int pmem_major;
-static void pmem_do_bvec(struct pmem_device *pmem, struct page *page,
+static bool is_bad_pmem(struct badblocks *bb, sector_t sector, unsigned int len)
+{
+ if (bb->count) {
+ sector_t first_bad;
+ int num_bad;
+
+ return !!badblocks_check(bb, sector, len / 512, &first_bad,
+ &num_bad);
+ }
+
+ return false;
+}
+
+static int pmem_do_bvec(struct pmem_device *pmem, struct page *page,
unsigned int len, unsigned int off, int rw,
sector_t sector)
{
@@ -56,6 +69,8 @@ static void pmem_do_bvec(struct pmem_device *pmem, struct page *page,
void __pmem *pmem_addr = pmem->virt_addr + pmem_off;
if (rw == READ) {
+ if (unlikely(is_bad_pmem(&pmem->bb, sector, len)))
+ return -EIO;
memcpy_from_pmem(mem + off, pmem_addr, len);
flush_dcache_page(page);
} else {
@@ -64,10 +79,12 @@ static void pmem_do_bvec(struct pmem_device *pmem, struct page *page,
}
kunmap_atomic(mem);
+ return 0;
}
static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
{
+ int rc = 0;
bool do_acct;
unsigned long start;
struct bio_vec bvec;
@@ -76,9 +93,15 @@ static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
struct pmem_device *pmem = bdev->bd_disk->private_data;
do_acct = nd_iostat_start(bio, &start);
- bio_for_each_segment(bvec, bio, iter)
- pmem_do_bvec(pmem, bvec.bv_page, bvec.bv_len, bvec.bv_offset,
- bio_data_dir(bio), iter.bi_sector);
+ bio_for_each_segment(bvec, bio, iter) {
+ rc = pmem_do_bvec(pmem, bvec.bv_page, bvec.bv_len,
+ bvec.bv_offset, bio_data_dir(bio),
+ iter.bi_sector);
+ if (rc) {
+ bio->bi_error = rc;
+ break;
+ }
+ }
if (do_acct)
nd_iostat_end(bio, start);
@@ -93,13 +116,22 @@ static int pmem_rw_page(struct block_device *bdev, sector_t sector,
struct page *page, int rw)
{
struct pmem_device *pmem = bdev->bd_disk->private_data;
+ int rc;
- pmem_do_bvec(pmem, page, PAGE_CACHE_SIZE, 0, rw, sector);
+ rc = pmem_do_bvec(pmem, page, PAGE_CACHE_SIZE, 0, rw, sector);
if (rw & WRITE)
wmb_pmem();
- page_endio(page, rw & WRITE, 0);
- return 0;
+ /*
+ * The ->rw_page interface is subtle and tricky. The core
+ * retries on any error, so we can only invoke page_endio() in
+ * the successful completion case. Otherwise, we'll see crashes
+ * caused by double completion.
+ */
+ if (rc == 0)
+ page_endio(page, rw & WRITE, 0);
+
+ return rc;
}
static long pmem_direct_access(struct block_device *bdev, sector_t sector,
Check the sectors specified in a read bio to see if they hit a known bad block, and return an error code pmem_do_bvec(). Note that the ->rw_page() is not in a position to return errors. For now, copy the same layering violation present in zram_rw_page() to avoid crashes of the form: kernel BUG at mm/filemap.c:822! [..] Call Trace: [<ffffffff811c540e>] page_endio+0x1e/0x60 [<ffffffff81290d29>] mpage_end_io+0x39/0x60 [<ffffffff8141c4ef>] bio_endio+0x3f/0x60 [<ffffffffa005c491>] pmem_make_request+0x111/0x230 [nd_pmem] ...i.e. unlock a page that was already unlocked via pmem_rw_page() => page_endio(). Reported-by: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- drivers/nvdimm/pmem.c | 46 +++++++++++++++++++++++++++++++++++++++------- 1 file changed, 39 insertions(+), 7 deletions(-)