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author | Matthew Wilcox <willy@linux.intel.com> | 2016-02-03 00:57:52 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-02-03 16:28:43 (GMT) |
commit | 46437f9a554fbe3e110580ca08ab703b59f2f95a (patch) | |
tree | 826c5a8180792c3c68f57686d41bf69f01b2985d /tools/usb | |
parent | 3c1da7beeee02560cd0f0c66c5a59fce3c6746e3 (diff) | |
download | linux-46437f9a554fbe3e110580ca08ab703b59f2f95a.tar.xz |
radix-tree: fix race in gang lookup
If the indirect_ptr bit is set on a slot, that indicates we need to redo
the lookup. Introduce a new function radix_tree_iter_retry() which
forces the loop to retry the lookup by setting 'slot' to NULL and
turning the iterator back to point at the problematic entry.
This is a pretty rare problem to hit at the moment; the lookup has to
race with a grow of the radix tree from a height of 0. The consequences
of hitting this race are that gang lookup could return a pointer to a
radix_tree_node instead of a pointer to whatever the user had inserted
in the tree.
Fixes: cebbd29e1c2f ("radix-tree: rewrite gang lookup using iterator")
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ohad Ben-Cohen <ohad@wizery.com>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'tools/usb')
0 files changed, 0 insertions, 0 deletions