ceph: Fix race between hole punch and page fault

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Ceph has a following race between hole punching and page fault:

CPU1                                  CPU2
ceph_fallocate()
  ...
  ceph_zero_pagecache_range()
                                      ceph_filemap_fault()
                                        faults in page in the range being
                                        punched
  ceph_zero_objects()

And now we have a page in punched range with invalid data. Fix the
problem by using mapping->invalidate_lock similarly to other
filesystems. Note that using invalidate_lock also fixes a similar race
wrt ->readpage().

CC: Jeff Layton <jlayton@kernel.org>
CC: ceph-devel@vger.kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>

...

This commit is contained in:

Jan Kara 2021-04-22 16:38:26 +02:00

parent 8bcbbe9c7c

commit 057ba5b245

2 changed files with 8 additions and 3 deletions

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9

fs/ceph/addr.c

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2

fs/ceph/file.c

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