A DM target can manage its own per-bio-data objects and attach them to
the new 'noclone_private' member in struct dm_noclone.
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
---
drivers/md/dm.c | 16 ++++++++--------
include/linux/device-mapper.h | 17 +++++++++++++++++
2 files changed, 25 insertions(+), 8 deletions(-)
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 6868b80fc70c..8ff0ced278d7 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -158,13 +158,6 @@ struct table_device {
struct dm_dev dm_dev;
};
-struct dm_noclone {
- struct mapped_device *md;
- bio_end_io_t *orig_bi_end_io;
- void *orig_bi_private;
- unsigned long start_time;
-};
-
static struct kmem_cache *_rq_tio_cache;
static struct kmem_cache *_rq_cache;
static struct kmem_cache *_noclone_cache;
@@ -1802,13 +1795,15 @@ static blk_qc_t dm_process_bio(struct mapped_device *md,
if (unlikely(!noclone))
goto no_fast_path;
+ noclone->magic = DM_NOCLONE_MAGIC;
noclone->md = md;
noclone->start_time = jiffies;
noclone->orig_bi_end_io = bio->bi_end_io;
noclone->orig_bi_private = bio->bi_private;
bio->bi_end_io = noclone_endio;
bio->bi_private = noclone;
- }
+ } else
+ noclone = bio->bi_private;
start_io_acct(md, bio);
r = ti->type->map(ti, bio);
@@ -1822,6 +1817,11 @@ static blk_qc_t dm_process_bio(struct mapped_device *md,
else
ret = generic_make_request(bio);
break;
+ case DM_MAPIO_NOCLONE_FAILED:
+ end_io_acct(md, bio, noclone->start_time);
+ kmem_cache_free(_noclone_cache, noclone);
+ goto no_fast_path;
+ break;
case DM_MAPIO_KILL:
bio_io_error(bio);
break;
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 4ab2b0f53ae8..b3e33d5cae8b 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -322,6 +322,22 @@ struct dm_target {
bool no_clone:1;
};
+#define DM_NOCLONE_MAGIC 9693664
+struct dm_noclone {
+ unsigned magic;
+ struct mapped_device *md;
+ bio_end_io_t *orig_bi_end_io;
+ void *orig_bi_private;
+ void *noclone_private;
+ unsigned long start_time;
+};
+
+static inline struct dm_noclone *dm_get_noclone_from_bio(struct bio *bio)
+{
+ struct dm_noclone *noclone = bio->bi_private;
+ return (noclone && noclone->magic == DM_NOCLONE_MAGIC) ? noclone : NULL;
+}
+
/* Each target can link one of these into the table */
struct dm_target_callbacks {
struct list_head list;
@@ -572,6 +588,7 @@ do { \
#define DM_MAPIO_REQUEUE DM_ENDIO_REQUEUE
#define DM_MAPIO_DELAY_REQUEUE DM_ENDIO_DELAY_REQUEUE
#define DM_MAPIO_KILL 4
+#define DM_MAPIO_NOCLONE_FAILED 5
#define dm_sector_div64(x, y)( \
{ \
--
2.15.0
--
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