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author | Tejun Heo <tj@kernel.org> | 2017-02-11 23:33:02 +0300 |
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committer | Tejun Heo <tj@kernel.org> | 2017-02-21 23:49:25 +0300 |
commit | f83f3c515654474e19c7fc86e3b06564bb5cb4d4 (patch) | |
tree | 17389a81a3e78f0051e4fb5d948f3d440f539cce /tools | |
parent | 63f1ca59453aadae81f702840c7ac6ea8b9f9262 (diff) | |
download | linux-f83f3c515654474e19c7fc86e3b06564bb5cb4d4.tar.xz |
kernfs: fix locking around kernfs_ops->release() callback
The release callback may be called from two places - file release
operation and kernfs open file draining. kernfs_open_file->mutex is
used to synchronize the two callsites. This unfortunately leads to
possible circular locking because of->mutex is used to protect the
usual kernfs operations which may use locking constructs which are
held while removing and thus draining kernfs files.
@of->mutex is for synchronizing concurrent kernfs access operations
and all we need here is synchronization between the releaes and drain
paths. As the drain path has to grab kernfs_open_file_mutex anyway,
let's use the mutex to synchronize the release operation instead.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-and-tested-by: Tony Lindgren <tony@atomide.com>
Fixes: 0e67db2f9fe9 ("kernfs: add kernfs_ops->open/release() callbacks")
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'tools')
0 files changed, 0 insertions, 0 deletions