user/sven/linux.git/include/linux/rculist_bl.h, branch v3.0.45Linux Kernel
https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v3.0.452011-01-14T02:36:43Zfs: hlist UP debug fixup2011-01-14T02:36:43ZNick Pigginnpiggin@kernel.dk2011-01-14T02:36:43Zurn:sha1:2c6755988afc003a0332406a134fb6a1626f9b28
Po-Yu Chuang <ratbert.chuang@gmail.com> noticed that hlist_bl_set_first could
crash on a UP system when LIST_BL_LOCKMASK is 0, because
LIST_BL_BUG_ON(!((unsigned long)h->first & LIST_BL_LOCKMASK));
always evaulates to true.
Fix the expression, and also avoid a dependency between bit spinlock
implementation and list bl code (list code shouldn't know anything
except that bit 0 is set when adding and removing elements). Eventually
if a good use case comes up, we might use this list to store 1 or more
arbitrary bits of data, so it really shouldn't be tied to locking either,
but for now they are helpful for debugging.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
kernel: add bl_list2011-01-07T06:50:31ZNick Pigginnpiggin@kernel.dk2011-01-07T06:50:03Zurn:sha1:4e35e6070b1ceed89c3bba2af4216c286fb1dafd
Introduce a type of hlist that can support the use of the lowest bit in the
hlist_head. This will be subsequently used to implement per-bucket bit spinlock
for inode and dentry hashes, and may be useful in other cases such as network
hashes.
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Nick Piggin <npiggin@kernel.dk>