IB/core: convert to idr_alloc()

Convert to the much saner new idr interface.

v2: Mike triggered WARN_ON() in idr_preload() because send_mad(),
    which may be used from non-process context, was calling
    idr_preload() unconditionally.  Preload iff @gfp_mask has
    __GFP_WAIT.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Sean Hefty <sean.hefty@intel.com>
Reported-by: "Marciniszyn, Mike" <mike.marciniszyn@intel.com>
Cc: Roland Dreier <roland@kernel.org>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 10 insertions, 8 deletions

diff --git a/drivers/infiniband/core/sa_query.c b/drivers/infiniband/core/sa_query.c
index a8905abc56e4..934f45e79e5e 100644
--- a/drivers/infiniband/core/sa_query.c
+++ b/drivers/infiniband/core/sa_query.c
@@ -611,19 +611,21 @@ static void init_mad(struct ib_sa_mad *mad, struct ib_mad_agent *agent)
 
 static int send_mad(struct ib_sa_query *query, int timeout_ms, gfp_t gfp_mask)
 {
+        bool preload = gfp_mask & __GFP_WAIT;
         unsigned long flags;
         int ret, id;
 
-retry:
-        if (!idr_pre_get(&query_idr, gfp_mask))
-                return -ENOMEM;
+        if (preload)
+                idr_preload(gfp_mask);
         spin_lock_irqsave(&idr_lock, flags);
-        ret = idr_get_new(&query_idr, query, &id);
+
+        id = idr_alloc(&query_idr, query, 0, 0, GFP_NOWAIT);
+
         spin_unlock_irqrestore(&idr_lock, flags);
-        if (ret == -EAGAIN)
-                goto retry;
-        if (ret)
-                return ret;
+        if (preload)
+                idr_preload_end();
+        if (id < 0)
+                return id;
 
         query->mad_buf->timeout_ms  = timeout_ms;
         query->mad_buf->context[0] = query;