blob: 9f31ecc823070a552f40f0da140e26ff3f39eafa (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
|
From 37f000c5aa76613e644cf3e5b1ec7bd2df6f7451 Mon Sep 17 00:00:00 2001
From: Ned Bass <bass6@llnl.gov>
Date: Wed, 26 Dec 2012 14:56:41 -0800
Subject: [PATCH] Fix gcc array subscript above bounds warning
In a debug build, certain GCC versions flag an array bounds warning in
the below code from dnode_sync.c
} else {
int i;
ASSERT(dn->dn_next_nblkptr[txgoff] < dnp->dn_nblkptr);
/* the blkptrs we are losing better be unallocated */
for (i = dn->dn_next_nblkptr[txgoff];
i < dnp->dn_nblkptr; i++)
ASSERT(BP_IS_HOLE(&dnp->dn_blkptr[i]));
This usage is in fact safe, since the ASSERT ensures the index does
not exceed to maximum possible number of block pointers. However gcc
can't determine that the assignment 'i = dn->dn_next_nblkptr[txgoff];'
falls within the array bounds so it issues a warning. To avoid this,
initialize i to zero to make gcc happy but skip the elements before
dn->dn_next_nblkptr[txgoff] in the loop body. Since a dnode contains
at most 3 block pointers this overhead should be negligible.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #950
---
module/zfs/dnode_sync.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/module/zfs/dnode_sync.c b/module/zfs/dnode_sync.c
index af636dc..f2dda86 100644
--- a/module/zfs/dnode_sync.c
+++ b/module/zfs/dnode_sync.c
@@ -666,9 +666,10 @@
int i;
ASSERT(dn->dn_next_nblkptr[txgoff] < dnp->dn_nblkptr);
/* the blkptrs we are losing better be unallocated */
- for (i = dn->dn_next_nblkptr[txgoff];
- i < dnp->dn_nblkptr; i++)
- ASSERT(BP_IS_HOLE(&dnp->dn_blkptr[i]));
+ for (i = 0; i < dnp->dn_nblkptr; i++) {
+ if (i >= dn->dn_next_nblkptr[txgoff])
+ ASSERT(BP_IS_HOLE(&dnp->dn_blkptr[i]));
+ }
#endif
}
mutex_enter(&dn->dn_mtx);
--
1.7.10
|
GitWeb
