Re: [PATCH -mm1 1/2] fixing idr_find() locking

From: Nadia Derbey
Date: Fri Sep 28 2007 - 03:03:24 EST

Jarek Poplawski wrote:
On Thu, Sep 27, 2007 at 04:33:55PM +0200, Nadia.Derbey@xxxxxxxx wrote:

[PATCH 01/02]

This is a patch that fixes the way idr_find() used to be called in ipc_lock():
in all the paths that don't imply an update of the ipcs idr, it was called
without the idr tree being locked.

The changes are:
. in ipc_ids, the mutex has been changed into a reader/writer semaphore.
. ipc_lock() now takes the mutex as a reader during the idr_find().
. a new routine ipc_lock_down() has been defined: it doesn't take the
mutex, assuming that it is being held by the caller. This is the routine
that is now called in all the update paths.

Signed-off-by: Nadia Derbey <Nadia.Derbey@xxxxxxxx>

Acked-by: Jarek Poplawski <jarkao2@xxxxx>

PS: there is one big mistake around To/Cc ordering, so I doubt Andrew
will ever sign this...


I thought that since you were the one who pointed out the issue I had to put you as the receiver.
Next time I'll also add Andrew in the To list.
Sorry for that.


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