The patch titled
Fix locking in nsm_release
has been added to the -mm tree. Its filename is
knfsd-lockd-introduce-nsm_handle-fix.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: Fix locking in nsm_release
From: Neil Brown <neilb@xxxxxxx>
The locking is all backwards and broken.
We first atomic_dec_and_test. If this fails, someone else has an active
reference and we need do no more.
If it succeeds, then the only ref is in the hash table, but someone might
be about to find and use that reference. nsm_mutex provides exclusion
against this. If sm_count is still 0 once the mutex has been gained, then
it is safe to discard the nsm.
Signed-off-by: Neil Brown <neilb@xxxxxxx>
Cc: Olaf Kirch <okir@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
fs/lockd/host.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff -puN fs/lockd/host.c~knfsd-lockd-introduce-nsm_handle-fix fs/lockd/host.c
--- a/fs/lockd/host.c~knfsd-lockd-introduce-nsm_handle-fix
+++ a/fs/lockd/host.c
@@ -483,9 +483,9 @@ nsm_release(struct nsm_handle *nsm)
{
if (!nsm)
return;
- if (atomic_read(&nsm->sm_count) == 1) {
+ if (atomic_dec_and_test(&nsm->sm_count)) {
down(&nsm_sema);
- if (atomic_dec_and_test(&nsm->sm_count)) {
+ if (atomic_read(&nsm->sm_count) == 0) {
list_del(&nsm->sm_link);
kfree(nsm);
}
_
Patches currently in -mm which might be from neilb@xxxxxxx are
vfs-destroy-the-dentries-contributed-by-a-superblock-on-unmounting.patch
knfsd-knfsd-add-some-missing-newlines-in-printks.patch
knfsd-knfsd-remove-an-unused-variable-from-e_show.patch
knfsd-knfsd-remove-an-unused-variable-from-auth_unix_lookup.patch
knfsd-add-a-callback-for-when-last-rpc-thread-finishes.patch
knfsd-add-a-callback-for-when-last-rpc-thread-finishes-tidy.patch
knfsd-be-more-selective-in-which-sockets-lockd-listens-on.patch
knfsd-remove-nfsd_versbits-as-intermediate-storage-for-desired-versions.patch
knfsd-separate-out-some-parts-of-nfsd_svc-which-start-nfs-servers.patch
knfsd-separate-out-some-parts-of-nfsd_svc-which-start-nfs-servers-tweaks.patch
knfsd-define-new-nfsdfs-file-portlist-contains-list-of-ports.patch
knfsd-define-new-nfsdfs-file-portlist-contains-list-of-ports-tidy.patch
knfsd-define-new-nfsdfs-file-portlist-contains-list-of-ports-fix.patch
knfsd-allow-sockets-to-be-passed-to-nfsd-via-portlist.patch
knfsd-use-seq_start_token-instead-of-hardcoded-magic-void1.patch
knfsd-have-ext2-reject-file-handles-with-bad-inode-numbers-early.patch
knfsd-have-ext2-reject-file-handles-with-bad-inode-numbers-early-tidy.patch
knfsd-make-ext3-reject-filehandles-referring-to-invalid-inode-numbers.patch
knfsd-make-ext3-reject-filehandles-referring-to-invalid-inode-numbers-tidy.patch
knfsd-drop-serv-option-to-svc_recv-and-svc_process.patch
knfsd-drop-serv-option-to-svc_recv-and-svc_process-nfs-callback-fix-nfs-callback-fix.patch
knfsd-check-return-value-of-lockd_up-in-write_ports.patch
knfsd-move-makesock-failed-warning-into-make_socks.patch
knfsd-correctly-handle-error-condition-from-lockd_up.patch
knfsd-move-tempsock-aging-to-a-timer.patch
knfsd-move-tempsock-aging-to-a-timer-tidy.patch
knfsd-convert-sk_inuse-to-atomic_t.patch
knfsd-use-new-lock-for-svc_sock-deferred-list.patch
knfsd-convert-sk_reserved-to-atomic_t.patch
knfsd-test-and-set-sk_busy-atomically.patch
knfsd-split-svc_serv-into-pools.patch
knfsd-split-svc_serv-into-pools-fix.patch
knfsd-add-svc_get.patch
knfsd-add-svc_set_num_threads.patch
knfsd-use-svc_set_num_threads-to-manage-threads-in-knfsd.patch
knfsd-make-rpc-threads-pools-numa-aware.patch
knfsd-make-rpc-threads-pools-numa-aware-fix.patch
knfsd-allow-admin-to-set-nthreads-per-node.patch
nfsd-lockdep-annotation.patch
knfsd-nfsd-lockdep-annotation-fix.patch
knfsd-call-lockd_down-when-closing-a-socket-via-a-write-to-nfsd-portlist.patch
knfsd-protect-update-to-sn_nrthreads-with-lock_kernel.patch
knfsd-fixed-handling-of-lockd-fail-when-adding-nfsd-socket.patch
knfsd-replace-two-page-lists-in-struct-svc_rqst-with-one.patch
knfsd-avoid-excess-stack-usage-in-svc_tcp_recvfrom.patch
knfsd-prepare-knfsd-for-support-of-rsize-wsize-of-up-to-1mb-over-tcp.patch
knfsd-allow-max-size-of-nfsd-payload-to-be-configured.patch
knfsd-make-nfsd-readahead-params-cache-smp-friendly.patch
knfsd-knfsd-cache-ipmap-per-tcp-socket.patch
knfsd-hide-use-of-lockds-h_monitored-flag.patch
knfsd-consolidate-common-code-for-statd-lockd-notification.patch
knfsd-when-looking-up-a-lockd-host-pass-hostname-length.patch
knfsd-lockd-introduce-nsm_handle.patch
knfsd-lockd-introduce-nsm_handle-fix.patch
knfsd-misc-minor-fixes-indentation-changes.patch
knfsd-lockd-make-nlm_host_rebooted-use-the-nsm_handle.patch
knfsd-lockd-make-the-nsm-upcalls-use-the-nsm_handle.patch
knfsd-lockd-make-the-hash-chains-use-a-hlist_node.patch
knfsd-lockd-change-list-of-blocked-list-to-list_node.patch
knfsd-change-nlm_file-to-use-a-hlist.patch
knfsd-lockd-make-nlm_traverse_-more-flexible.patch
knfsd-lockd-add-nlm_destroy_host.patch
knfsd-simplify-nlmsvc_invalidate_all.patch
knfsd-lockd-optionally-use-hostnames-for-identifying-peers.patch
knfsd-make-nlmclnt_next_cookie-smp-safe.patch
knfsd-match-granted_res-replies-using-cookies.patch
knfsd-export-nsm_local_state-to-user-space-via-sysctl.patch
knfsd-lockd-fix-use-of-h_nextrebind.patch
knfsd-register-all-rpc-programs-with-portmapper-by-default.patch
knfsd-lockd-introduce-nsm_handle-sem2mutex.patch
md-the-scheduled-removal-of-the-start_array-ioctl-for-md.patch
md-fix-a-comment-that-is-wrong-in-raid5h.patch
md-factor-out-part-of-raid10d-into-a-separate-function.patch
md-replace-magic-numbers-in-sb_dirty-with-well-defined-bit-flags.patch
md-remove-the-working_disks-and-failed_disks-from-raid5-state-data.patch
md-remove-working_disks-from-raid10-state.patch
md-new-sysfs-interface-for-setting-bits-in-the-write-intent-bitmap.patch
md-remove-unnecessary-variable-x-in-stripe_to_pdidx.patch
md-factor-out-part-of-raid1d-into-a-separate-function.patch
md-remove-working_disks-from-raid1-state-data.patch
md-improve-locking-around-error-handling.patch
md-define-backing_dev_infocongested_fn-for-raid0-and-linear.patch
md-define-congested_fn-for-raid1-raid10-and-multipath.patch
md-add-a-congested_fn-function-for-raid5-6.patch
md-make-messages-about-resync-recovery-etc-more-specific.patch
md-dm-reduce-stack-usage-with-stacked-block-devices.patch
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