diff options
| author | J. Bruce Fields <bfields@citi.umich.edu> | 2007-07-19 01:49:18 -0700 |
|---|---|---|
| committer | Willy Tarreau <w@1wt.eu> | 2007-08-25 17:24:09 +0200 |
| commit | 25d919bd316afa283e1d758967923fddcff83fd8 (patch) | |
| tree | 93125546273efb777b781f3a23bc80eeff44c562 | |
| parent | 50dd9072c45f64348e10ae61df948fef43430a0e (diff) | |
[PATCH] nfsd: fix possible read-ahead cache and export table corruption
The value of nperbucket calculated here is too small--we should be rounding up
instead of down--with the result that the index j in the following loop can
overflow the raparm_hash array. At least in my case, the next thing in memory
turns out to be export_table, so the symptoms I see are crashes caused by the
appearance of four zeroed-out export entries in the first bucket of the hash
table of exports (which were actually entries in the readahead cache, a
pointer to which had been written to the export table in this initialization
code).
It looks like the bug was probably introduced with commit
fce1456a19f5c08b688c29f00ef90fdfa074c79b ("knfsd: make the readahead params
cache SMP-friendly").
Cc: Greg Banks <gnb@melbourne.sgi.com>
Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Willy Tarreau <w@1wt.eu>
| -rw-r--r-- | fs/nfsd/vfs.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index 8283236c6a0f..d8b773a786a6 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -1887,7 +1887,7 @@ nfsd_racache_init(int cache_size) raparm_hash[i].pb_head = NULL; spin_lock_init(&raparm_hash[i].pb_lock); } - nperbucket = cache_size >> RAPARM_HASH_BITS; + nperbucket = DIV_ROUND_UP(cache_size, RAPARM_HASH_SIZE); for (i = 0; i < cache_size - 1; i++) { if (i % nperbucket == 0) raparm_hash[j++].pb_head = raparml + i; |