* [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
--
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https://www.redhat.com/mailman/listinfo/dm-devel
^ permalink raw reply related [flat|nested] 2+ messages in thread
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