Move xen patchset to new version's subdir.

[people/pmueller/ipfire-2.x.git] / src / patches / suse-2.6.27.25 / patches.fixes / dm-avoid-put-table-dm_any_congested

diff --git a/src/patches/suse-2.6.27.25/patches.fixes/dm-avoid-put-table-dm_any_congested b/src/patches/suse-2.6.27.25/patches.fixes/dm-avoid-put-table-dm_any_congested
deleted file mode 100644 (file)
index c8d36c3..0000000
--- a/src/patches/suse-2.6.27.25/patches.fixes/dm-avoid-put-table-dm_any_congested
+++ /dev/null
@@ -1,82 +0,0 @@
-From: Chandra Seetharaman <sekharan@us.ibm.com>
-Subject: dm: avoid destroying table in dm_any_congested
-References: bnc#457205
-Patch-mainline: 2.6.28-rc4
-Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
-
-[PATCH 1/3] for bnc 457205. Even though this fix is almost
-reverted by 3rd patch in this series, this patch is used as it
-fixes a suble bug of calling dm_table_put only when dm_get_table
-succeeds. Also this makes code more inline with the mainline.
-
-mainline commit 8a57dfc6f943c92b861c9a19b0c86ddcb2aba768
-    
-    dm_any_congested() just checks for the DMF_BLOCK_IO and has no
-    code to make sure that suspend waits for dm_any_congested() to
-    complete.  This patch adds such a check.
-    
-    Without it, a race can occur with dm_table_put() attempting to
-    destroying the table in the wrong thread, the one running
-    dm_any_congested() which is meant to be quick and return
-    immediately.
-    
-    Two examples of problems:
-    1. Sleeping functions called from congested code, the caller
-       of which holds a spin lock.
-    2. An ABBA deadlock between pdflush and multipathd. The two locks
-       in contention are inode lock and kernel lock.
-    
-    Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
-    Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
-    Signed-off-by: Alasdair G Kergon <agk@redhat.com>
-
-Index: linux-2.6.27/drivers/md/dm.c
-===================================================================
---- linux-2.6.27.orig/drivers/md/dm.c
-+++ linux-2.6.27/drivers/md/dm.c
-@@ -1640,22 +1640,32 @@ static void dm_unplug_all(struct request
- 
- static int dm_any_congested(void *congested_data, int bdi_bits)
- {
--      int r;
-+      int r = bdi_bits;
-       struct mapped_device *md = (struct mapped_device *) congested_data;
--      struct dm_table *map = dm_get_table(md);
-+      struct dm_table *map;
- 
--      if (!map || test_bit(DMF_BLOCK_IO, &md->flags))
--              r = bdi_bits;
--      else if (dm_request_based(md))
--              /*
--               * Request-based dm cares about only own queue for
--               * the query about congestion status of request_queue
--               */
--              r = md->queue->backing_dev_info.state & bdi_bits;
--      else
--              r = dm_table_any_congested(map, bdi_bits);
-+      atomic_inc(&md->pending);
-+
-+      if (!test_bit(DMF_BLOCK_IO, &md->flags)) {
-+              map = dm_get_table(md);
-+              if (map) {
-+                      if (dm_request_based(md))
-+                              /*
-+                               * Request-based dm cares about only own queue for
-+                               * the query about congestion status of request_queue
-+                               */
-+                              r = md->queue->backing_dev_info.state & bdi_bits;
-+                      else
-+                              r = dm_table_any_congested(map, bdi_bits);
-+                      dm_table_put(map);
-+              }
-+      }
-+
-+
-+      if (!atomic_dec_return(&md->pending))
-+              /* nudge anyone waiting on suspend queue */
-+              wake_up(&md->wait);
- 
--      dm_table_put(map);
-       return r;
- }
-