[PATCH 04/35] dax: Fix inefficiency in dax_writeback_mapping_range()
From: Jan Kara <jack@suse.cz>
Date: 2017-06-01 09:33:17
Also in:
ceph-devel, linux-btrfs, linux-f2fs-devel, linux-mm, linux-xfs, stable
Subsystem:
filesystem direct access (dax), filesystems (vfs and infrastructure), the rest · Maintainers:
Dan Williams, Alexander Viro, Christian Brauner, Linus Torvalds
dax_writeback_mapping_range() fails to update iteration index when searching radix tree for entries needing cache flushing. Thus each pagevec worth of entries is searched starting from the start which is inefficient and prone to livelocks. Update index properly. CC: stable@vger.kernel.org Fixes: 9973c98ecfda3a1dfcab981665b5f1e39bcde64a Signed-off-by: Jan Kara <jack@suse.cz> --- fs/dax.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/fs/dax.c b/fs/dax.c
index c22eaf162f95..c204445a69b0 100644
--- a/fs/dax.c
+++ b/fs/dax.c@@ -859,6 +859,7 @@ int dax_writeback_mapping_range(struct address_space *mapping, if (ret < 0) goto out; } + start_index = indices[pvec.nr - 1] + 1; } out: put_dax(dax_dev);
--
2.12.3
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