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From: Nikita Danilov <Nikita@Namesys.COM>
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Cc: Andrew Morton <AKPM@Digeo.COM>, Alexander Viro <viro@math.psu.edu>
Subject: possible deadlock in sys_pivot_root()?
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Hello,

sys_pivot_root() first takes BKL, then ->i_sem on the old root
directory. On the other hand, vfs_readdir() first takes ->i_sem on a
directory and then calls file system ->readdir() method, that usually
takes BKL. Isn't there a deadlock possibility? Of course,
sys_pivot_root() is probably not supposed to be called frequently, but
still.

Nikita.