IB/fmr_pool: Flush all dirty FMRs from ib_fmr_pool_flush()

Commit a3cd7d90 ("IB/fmr_pool: ib_fmr_pool_flush() should flush all
dirty FMRs") caused a regression for iSER and was reverted in
e5507736.

This change attempts to redo the original patch so that all used FMR
entries are flushed when ib_flush_fmr_pool() is called without
affecting the normal FMR pool cleaning thread.  Simply move used
entries from the clean list onto the dirty list in ib_flush_fmr_pool()
before letting the cleanup thread do its job.

Signed-off-by: Pete Wyckoff <pw@osc.edu>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 16 insertions, 1 deletions

diff --git a/drivers/infiniband/core/fmr_pool.c b/drivers/infiniband/core/fmr_pool.c
index 4044fdf62cc2..06d502c06a4d 100644
--- a/drivers/infiniband/core/fmr_pool.c
+++ b/drivers/infiniband/core/fmr_pool.c
@@ -398,8 +398,23 @@ EXPORT_SYMBOL(ib_destroy_fmr_pool);
  */
 int ib_flush_fmr_pool(struct ib_fmr_pool *pool)
 {
-        int serial = atomic_inc_return(&pool->req_ser);
+        int serial;
+        struct ib_pool_fmr *fmr, *next;
+
+        /*
+         * The free_list holds FMRs that may have been used
+         * but have not been remapped enough times to be dirty.
+         * Put them on the dirty list now so that the cleanup
+         * thread will reap them too.
+         */
+        spin_lock_irq(&pool->pool_lock);
+        list_for_each_entry_safe(fmr, next, &pool->free_list, list) {
+                if (fmr->remap_count > 0)
+                        list_move(&fmr->list, &pool->dirty_list);
+        }
+        spin_unlock_irq(&pool->pool_lock);
 
+        serial = atomic_inc_return(&pool->req_ser);
         wake_up_process(pool->thread);
 
         if (wait_event_interruptible(pool->force_wait,