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| author | Artem Bityutskiy <Artem.Bityutskiy@nokia.com> | 2010-08-08 12:45:23 +0300 |
|---|---|---|
| committer | Artem Bityutskiy <Artem.Bityutskiy@nokia.com> | 2010-08-30 10:19:08 +0300 |
| commit | 1a9476a77083354005750c9df45ba9d71ad12c8c (patch) | |
| tree | 2e032a6f9071620ece14b69d4fedd35a1ba0d2d1 /fs/ubifs | |
| parent | ba2f48f70efcf4d82deafb2be327ed64b1f043a5 (diff) | |
| download | lwn-1a9476a77083354005750c9df45ba9d71ad12c8c.tar.gz lwn-1a9476a77083354005750c9df45ba9d71ad12c8c.zip | |
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>
Diffstat (limited to 'fs/ubifs')
| -rw-r--r-- | fs/ubifs/gc.c | 6 |
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); |