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authorArtem Bityutskiy <Artem.Bityutskiy@nokia.com>2010-08-08 12:45:23 +0300
committerArtem Bityutskiy <Artem.Bityutskiy@nokia.com>2010-08-30 10:19:08 +0300
commit1a9476a77083354005750c9df45ba9d71ad12c8c (patch)
tree2e032a6f9071620ece14b69d4fedd35a1ba0d2d1
parentba2f48f70efcf4d82deafb2be327ed64b1f043a5 (diff)
downloadlinux-1a9476a77083354005750c9df45ba9d71ad12c8c.tar.bz2
UBIFS: fix assertion warnings in comparison function
When running the integrity test ('integck' from mtd-utils) on current UBIFS on 2.6.35, I see that assertions in UBIFS 'list_sort()' comparison functions trigger sometimes, e.g.: UBIFS assert failed in data_nodes_cmp at 132 (pid 28311) My investigation showed that this happens when 'list_sort()' calls the 'cmp()' function with equivalent arguments. In this case, the 'struct list_head' parameter, passed to 'cmp()' is bogus, and it does not belong to any element in the original list. And this issue seems to be introduced by commit: commit 835cc0c8477fdbc59e0217891d6f11061b1ac4e2 Author: Don Mullis <don.mullis@gmail.com> Date: Fri Mar 5 13:43:15 2010 -0800 It is easy to work around the issue by doing: if (a == b) return 0; in UBIFS. It works, but 'lib_sort()' should nevertheless be fixed. Although it is harmless to have this piece of code in UBIFS. This patch adds that code to both UBIFS 'cmp()' functions: 'data_nodes_cmp()' and 'nondata_nodes_cmp()'. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
-rw-r--r--fs/ubifs/gc.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/ubifs/gc.c b/fs/ubifs/gc.c
index dafef3d195d3..4fc31ca0e3b1 100644
--- a/fs/ubifs/gc.c
+++ b/fs/ubifs/gc.c
@@ -125,6 +125,9 @@ int data_nodes_cmp(void *priv, struct list_head *a, struct list_head *b)
struct ubifs_scan_node *sa, *sb;
cond_resched();
+ if (a == b)
+ return 0;
+
sa = list_entry(a, struct ubifs_scan_node, list);
sb = list_entry(b, struct ubifs_scan_node, list);
@@ -165,6 +168,9 @@ int nondata_nodes_cmp(void *priv, struct list_head *a, struct list_head *b)
struct ubifs_scan_node *sa, *sb;
cond_resched();
+ if (a == b)
+ return 0;
+
sa = list_entry(a, struct ubifs_scan_node, list);
sb = list_entry(b, struct ubifs_scan_node, list);