diff options
| author |   Jens Axboe <jaxboe@fusionio.com> | 2011-03-01 15:04:39 -0500 |
|---|---|---|
| committer | Jens Axboe <jaxboe@fusionio.com> | 2011-03-01 15:04:39 -0500 |
| commit | 6fae9c25134baffbeeb20031479e7ff6f6d8eec0 (patch) | |
| tree | c9ab89992ce5293a43cd455a81dc8a5926a28a5e /include/linux/radix-tree.h | |
| parent | block: share request flush fields with elevator_private (diff) | |
| parent | Linux 2.6.38-rc6 (diff) | |
| download | linux-dev-6fae9c25134baffbeeb20031479e7ff6f6d8eec0.tar.xz linux-dev-6fae9c25134baffbeeb20031479e7ff6f6d8eec0.zip | |
Merge commit 'v2.6.38-rc6' into for-2.6.39/core
Conflicts:
block/cfq-iosched.c
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Diffstat (limited to 'include/linux/radix-tree.h')
| -rw-r--r-- | include/linux/radix-tree.h | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h index ab2baa5c4884..23241c2fecce 100644 --- a/include/linux/radix-tree.h +++ b/include/linux/radix-tree.h @@ -146,6 +146,22 @@ static inline void *radix_tree_deref_slot(void **pslot) } /** + * radix_tree_deref_slot_protected - dereference a slot without RCU lock but with tree lock held + * @pslot: pointer to slot, returned by radix_tree_lookup_slot + * Returns: item that was stored in that slot with any direct pointer flag + * removed. + * + * Similar to radix_tree_deref_slot but only used during migration when a pages + * mapping is being moved. The caller does not hold the RCU read lock but it + * must hold the tree lock to prevent parallel updates. + */ +static inline void *radix_tree_deref_slot_protected(void **pslot, + spinlock_t *treelock) +{ + return rcu_dereference_protected(*pslot, lockdep_is_held(treelock)); +} + +/** * radix_tree_deref_retry - check radix_tree_deref_slot * @arg: pointer returned by radix_tree_deref_slot * Returns: 0 if retry is not required, otherwise retry is required |