All of lore.kernel.org
 help / color / mirror / Atom feed
* [PATCH] dm persistent data: fix return type of shadow_root
@ 2021-01-17 11:49 ` Jinoh Kang
  0 siblings, 0 replies; 2+ messages in thread
From: Jinoh Kang @ 2021-01-17 11:49 UTC (permalink / raw)
  To: dm-devel; +Cc: Alasdair Kergon, Mike Snitzer, Joe Thornber, linux-kernel

shadow_root() truncates 64-bit dm_block_t into 32-bit int.  This is
not an issue in practice, since dm metadata as of v5.11 can only hold at
most 4161600 blocks (255 index entries * ~16k metadata blocks).

Nevertheless, this can confuse users debugging some specific data
corruption scenarios.  Also, DM_SM_METADATA_MAX_BLOCKS may be bumped in
the future, or persistent-data may find its use in other places.

Therefore, switch the return type of shadow_root from int to dm_block_t.

Fixes: 3241b1d3e0aa ("dm: add persistent data library")
Cc: stable@vger.kernel.org
Signed-off-by: Jinoh Kang <jinoh.kang.kr@gmail.com>
---
 drivers/md/persistent-data/dm-btree-internal.h | 2 +-
 drivers/md/persistent-data/dm-btree-spine.c    | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/md/persistent-data/dm-btree-internal.h b/drivers/md/persistent-data/dm-btree-internal.h
index 564896659dd4..fe073d92f01e 100644
--- a/drivers/md/persistent-data/dm-btree-internal.h
+++ b/drivers/md/persistent-data/dm-btree-internal.h
@@ -100,7 +100,7 @@ struct dm_block *shadow_parent(struct shadow_spine *s);
 
 int shadow_has_parent(struct shadow_spine *s);
 
-int shadow_root(struct shadow_spine *s);
+dm_block_t shadow_root(struct shadow_spine *s);
 
 /*
  * Some inlines.
diff --git a/drivers/md/persistent-data/dm-btree-spine.c b/drivers/md/persistent-data/dm-btree-spine.c
index e03cb9e48773..8a2bfbfb218b 100644
--- a/drivers/md/persistent-data/dm-btree-spine.c
+++ b/drivers/md/persistent-data/dm-btree-spine.c
@@ -235,7 +235,7 @@ int shadow_has_parent(struct shadow_spine *s)
 	return s->count >= 2;
 }
 
-int shadow_root(struct shadow_spine *s)
+dm_block_t shadow_root(struct shadow_spine *s)
 {
 	return s->root;
 }
-- 
2.26.2


^ permalink raw reply related	[flat|nested] 2+ messages in thread

* [dm-devel] [PATCH] dm persistent data: fix return type of shadow_root
@ 2021-01-17 11:49 ` Jinoh Kang
  0 siblings, 0 replies; 2+ messages in thread
From: Jinoh Kang @ 2021-01-17 11:49 UTC (permalink / raw)
  To: dm-devel; +Cc: Joe Thornber, Mike Snitzer, Alasdair Kergon, linux-kernel

shadow_root() truncates 64-bit dm_block_t into 32-bit int.  This is
not an issue in practice, since dm metadata as of v5.11 can only hold at
most 4161600 blocks (255 index entries * ~16k metadata blocks).

Nevertheless, this can confuse users debugging some specific data
corruption scenarios.  Also, DM_SM_METADATA_MAX_BLOCKS may be bumped in
the future, or persistent-data may find its use in other places.

Therefore, switch the return type of shadow_root from int to dm_block_t.

Fixes: 3241b1d3e0aa ("dm: add persistent data library")
Cc: stable@vger.kernel.org
Signed-off-by: Jinoh Kang <jinoh.kang.kr@gmail.com>
---
 drivers/md/persistent-data/dm-btree-internal.h | 2 +-
 drivers/md/persistent-data/dm-btree-spine.c    | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/md/persistent-data/dm-btree-internal.h b/drivers/md/persistent-data/dm-btree-internal.h
index 564896659dd4..fe073d92f01e 100644
--- a/drivers/md/persistent-data/dm-btree-internal.h
+++ b/drivers/md/persistent-data/dm-btree-internal.h
@@ -100,7 +100,7 @@ struct dm_block *shadow_parent(struct shadow_spine *s);
 
 int shadow_has_parent(struct shadow_spine *s);
 
-int shadow_root(struct shadow_spine *s);
+dm_block_t shadow_root(struct shadow_spine *s);
 
 /*
  * Some inlines.
diff --git a/drivers/md/persistent-data/dm-btree-spine.c b/drivers/md/persistent-data/dm-btree-spine.c
index e03cb9e48773..8a2bfbfb218b 100644
--- a/drivers/md/persistent-data/dm-btree-spine.c
+++ b/drivers/md/persistent-data/dm-btree-spine.c
@@ -235,7 +235,7 @@ int shadow_has_parent(struct shadow_spine *s)
 	return s->count >= 2;
 }
 
-int shadow_root(struct shadow_spine *s)
+dm_block_t shadow_root(struct shadow_spine *s)
 {
 	return s->root;
 }
-- 
2.26.2

--
dm-devel mailing list
dm-devel@redhat.com
https://www.redhat.com/mailman/listinfo/dm-devel


^ permalink raw reply related	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2021-01-18  9:02 UTC | newest]

Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-01-17 11:49 [PATCH] dm persistent data: fix return type of shadow_root Jinoh Kang
2021-01-17 11:49 ` [dm-devel] " Jinoh Kang

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.