tree 1c4235ec8ac0e8e7f75a6f97ea6169e93647004f
parent 85b872424984e79519be904e7df02a91ba0a9486
author Dipankar Sarma <dipankar@in.ibm.com> 1134376625 -0800
committer Linus Torvalds <torvalds@g5.osdl.org> 1134406662 -0800

[PATCH] add rcu_barrier() synchronization point

This introduces a new interface - rcu_barrier() which waits until all
the RCUs queued until this call have been completed.

Reiser4 needs this, because we do more than just freeing memory object
in our RCU callback: we also remove it from the list hanging off
super-block.  This means, that before freeing reiser4-specific portion
of super-block (during umount) we have to wait until all pending RCU
callbacks are executed.

The only change of reiser4 made to the original patch, is exporting of
rcu_barrier().

Cc: Hans Reiser <reiser@namesys.com>
Cc: Vladimir V. Saveliev <vs@namesys.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>