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author | Alexander Aring <aahringo@redhat.com> | 2023-09-13 00:53:20 +0300 |
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committer | Chuck Lever <chuck.lever@oracle.com> | 2023-10-16 19:44:02 +0300 |
commit | afb13302aa664170684c76b0c12ece37b4e91d12 (patch) | |
tree | f36064e400683539fb27cfbf5a785630f18c467f /fs/lockd/svc.c | |
parent | b743612c0aaa49a781f1f0c760e35d7298b5c5b4 (diff) | |
download | linux-afb13302aa664170684c76b0c12ece37b4e91d12.tar.xz |
lockd: fix race in async lock request handling
This patch fixes a race in async lock request handling between adding
the relevant struct nlm_block to nlm_blocked list after the request was
sent by vfs_lock_file() and nlmsvc_grant_deferred() does a lookup of the
nlm_block in the nlm_blocked list. It could be that the async request is
completed before the nlm_block was added to the list. This would end
in a -ENOENT and a kernel log message of "lockd: grant for unknown
block".
To solve this issue we add the nlm_block before the vfs_lock_file() call
to be sure it has been added when a possible nlmsvc_grant_deferred() is
called. If the vfs_lock_file() results in an case when it wouldn't be
added to nlm_blocked list, the nlm_block struct will be removed from
this list again.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Diffstat (limited to 'fs/lockd/svc.c')
0 files changed, 0 insertions, 0 deletions