+ btrfs-fix-race-in-btrfs_free_dummy_fs_info.patch added to -mm tree

+ btrfs-fix-race-in-btrfs_free_dummy_fs_info.patch added to -mm tree

[akpm]

The patch titled
     Subject: btrfs: fix race in btrfs_free_dummy_fs_info()
has been added to the -mm tree.  Its filename is
     btrfs-fix-race-in-btrfs_free_dummy_fs_info.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/btrfs-fix-race-in-btrfs_free_dummy_fs_info.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/btrfs-fix-race-in-btrfs_free_dummy_fs_info.patch

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*** Remember to use Documentation/SubmitChecklist when testing your code ***

The -mm tree is included into linux-next and is updated
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------------------------------------------------------
From: Matthew Wilcox <mawilcox@microsoft.com>
Subject: btrfs: fix race in btrfs_free_dummy_fs_info()

We drop the lock which protects the radix tree, so we must call
radix_tree_iter_next() in order to avoid a modification to the tree
invalidating the iterator state.

Link: http://lkml.kernel.org/r/1480369871-5271-54-git-send-email-mawilcox@linuxonhyperv.com
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/btrfs/tests/btrfs-tests.c |    1 +
 1 file changed, 1 insertion(+)

diff -puN fs/btrfs/tests/btrfs-tests.c~btrfs-fix-race-in-btrfs_free_dummy_fs_info fs/btrfs/tests/btrfs-tests.c
--- a/fs/btrfs/tests/btrfs-tests.c~btrfs-fix-race-in-btrfs_free_dummy_fs_info
+++ a/fs/btrfs/tests/btrfs-tests.c
@@ -162,6 +162,7 @@ void btrfs_free_dummy_fs_info(struct btr
 				slot = radix_tree_iter_retry(&iter);
 			continue;
 		}
+		slot = radix_tree_iter_next(&iter);
 		spin_unlock(&fs_info->buffer_lock);
 		free_extent_buffer_stale(eb);
 		spin_lock(&fs_info->buffer_lock);
_

Patches currently in -mm which might be from mawilcox@microsoft.com are

radix-tree-test-suite-fix-compilation.patch
radix-tree-test-suite-iteration-test-misuses-rcu.patch
radix-tree-test-suite-use-rcu_barrier.patch
radix-tree-test-suite-handle-exceptional-entries.patch
radix-tree-test-suite-record-order-in-each-item.patch
btrfs-fix-race-in-btrfs_free_dummy_fs_info.patch
radix-tree-improve-multiorder-iterators.patch
radix-tree-delete-radix_tree_locate_item.patch
radix-tree-delete-radix_tree_range_tag_if_tagged.patch
radix-tree-fix-replacement-for-multiorder-entries.patch
radix-tree-test-suite-check-multiorder-iteration.patch
tpm-use-idr_find-not-idr_find_slowpath.patch
rxrpc-abstract-away-knowledge-of-idr-internals.patch