tree 29ba46cea17454fe1888182f6722aee64e1a7ef5
parent bacac382fbf53f717ca7f83558e45cce44e67df9
author Miklos Szeredi <miklos@szeredi.hu> 1137478492 -0800
committer Linus Torvalds <torvalds@g5.osdl.org> 1137482131 -0800

[PATCH] fuse: fix bitfield race

Fix race in setting bitfields of fuse_conn.  Spotted by Andrew Morton.

The two fields ->connected and ->mounted were always changed with the
fuse_lock held.  But other bitfields in the same structure were changed
without the lock.  In theory this could lead to losing the assignment of
even the ones under lock.  The chosen solution is to change these two
fields to be a full unsigned type.  The other bitfields aren't "important"
enough to warrant the extra complexity of full locking or changing them to
bitops.

For all bitfields document why they are safe wrt. concurrent
assignments.

Also make the initialization of the 'num_waiting' atomic counter explicit.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>