I posted this to the newsgroup news:linux-kernel but got no response...
I'll try here.
While going thru the kernel code for 2.4.17 (uClinux patch) I noticed a
problem with functions in 3 files:
dcache_init in fs/dcache.c, inode_init in fs/inode.c and in mnt_init in
fs/namespace.c
At least on my Redhat 7.3 2.4.18-10 source, in the function
static void __init dcache_init(unsigned long mempages)
{
struct list_head *d;
unsigned long order;
unsigned int nr_hash;
int i;
/*
* A constructor could be added for stable state like the lists,
* but it is probably not worth it because of the cache nature
* of the dcache.
* If fragmentation is too bad then the SLAB_HWCACHE_ALIGN
* flag could be removed here, to hint to the allocator that
* it should not try to get multiple page regions.
*/
dentry_cache = kmem_cache_create("dentry_cache",
sizeof(struct dentry),
0,
SLAB_HWCACHE_ALIGN,
NULL, NULL);
if (!dentry_cache)
panic("Cannot create dentry cache");
#if PAGE_SHIFT < 13
mempages >>= (13 - PAGE_SHIFT);
#endif
mempages *= sizeof(struct list_head);
for (order = 0; ((1UL << order) << PAGE_SHIFT) < mempages; order++)
;
do {
u32 tmp;
nr_hash = (1UL << order) * PAGE_SIZE /
sizeof(struct list_head);
d_hash_mask = (nr_hash - 1);
tmp = nr_hash;
d_hash_shift = 0;
while ((tmp >>= 1UL) != 0UL)
d_hash_shift++;
dentry_hashtable = (struct list_head *)
__get_free_pages(GFP_ATOMIC, order);
} while (dentry_hashtable == NULL && --order >= 0);
........... Notice the --order >=0 in the do while test... since order
is declared as an unsigned long, this test is a pointless comparison and
never fails, causing an infinite loop if the hashtable is empty.
My fix to this is to change the test to have
while (dentry_hashtable == NULL && order-- != 0);
Could someone check me on this?
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This archive was generated by hypermail 2b29 : Sat Aug 31 2002 - 22:00:21 EST