• Roland Dreier's avatar
    [PATCH] Convert idr's internal locking to _irqsave variant · c259cc28
    Roland Dreier authored
    Currently, the code in lib/idr.c uses a bare spin_lock(&idp->lock) to do
    internal locking.  This is a nasty trap for code that might call idr
    functions from different contexts; for example, it seems perfectly
    reasonable to call idr_get_new() from process context and idr_remove() from
    interrupt context -- but with the current locking this would lead to a
    potential deadlock.
    The simplest fix for this is to just convert the idr locking to use
    In particular, this fixes a very complicated locking issue detected by
    lockdep, involving the ib_ipoib driver's priv->lock and dev->_xmit_lock,
    which get involved with the ib_sa module's query_idr.lock.
    Cc: Arjan van de Ven <arjan@infradead.org>
    Cc: Ingo Molnar <mingo@elte.hu>
    Cc: Zach Brown <zach.brown@oracle.com>,
    Signed-off-by: default avatarRoland Dreier <rolandd@cisco.com>
    Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
idr.c 10.9 KB