The commit message of commit 6ec1f0239485 ("md/md-bitmap: fix stats
collection for external bitmaps") states:
Remove the external bitmap check as the statistics should be
available regardless of bitmap storage location.
Return -EINVAL only for invalid bitmap with no storage (neither in
superblock nor in external file).
But, the code does not adhere to the above, as it does only check for
a valid super-block for "internal" bitmaps. Hence, we observe:
Oops: GPF, probably for non-canonical address 0x1cd66f1f40000028
RIP: 0010:bitmap_get_stats+0x45/0xd0
Call Trace:
seq_read_iter+0x2b9/0x46a
seq_read+0x12f/0x180
proc_reg_read+0x57/0xb0
vfs_read+0xf6/0x380
ksys_read+0x6d/0xf0
do_syscall_64+0x8c/0x1b0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
We fix this by checking the existence of a super-block for both the
internal and external case.
Fixes: 6ec1f0239485 ("md/md-bitmap: fix stats collection for external bitmaps")
Cc: stable@xxxxxxxxxxxxxxx
Reported-by: Gerald Gibson <gerald.gibson@xxxxxxxxxx>
Signed-off-by: Håkon Bugge <haakon.bugge@xxxxxxxxxx>
---
drivers/md/md-bitmap.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c
index bd694910b01b0..7f524a26cebca 100644
--- a/drivers/md/md-bitmap.c
+++ b/drivers/md/md-bitmap.c
@@ -2366,8 +2366,7 @@ static int bitmap_get_stats(void *data, struct md_bitmap_stats *stats)
if (!bitmap)
return -ENOENT;
- if (!bitmap->mddev->bitmap_info.external &&
- !bitmap->storage.sb_page)
+ if (!bitmap->storage.sb_page)
return -EINVAL;
sb = kmap_local_page(bitmap->storage.sb_page);
stats->sync_size = le64_to_cpu(sb->sync_size);
--
2.43.5
