On Thu, 2016-10-13 at 15:26 +1100, NeilBrown wrote:
> A process can have two possible lock owner for a given open file:
> a per-process Posix lock owner and a per-open-file flock owner
> Use both of these when searching for a suitable stateid to use.
>
> With this patch, READ/WRITE requests will use the correct stateid
> if a flock lock is active.
>
> Signed-off-by: NeilBrown <neilb@xxxxxxxx>
> ---
> fs/nfs/nfs4state.c | 14 +++++++++-----
> 1 file changed, 9 insertions(+), 5 deletions(-)
>
> diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
> index f25eee8202bf..ed39ee164f5f 100644
> --- a/fs/nfs/nfs4state.c
> +++ b/fs/nfs/nfs4state.c
> @@ -800,11 +800,13 @@ void nfs4_close_sync(struct nfs4_state *state, fmode_t fmode)
> * that is compatible with current->files
> */
> static struct nfs4_lock_state *
> -__nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
> +__nfs4_find_lock_state(struct nfs4_state *state,
> + fl_owner_t fl_owner, fl_owner_t fl_owner2)
> {
> struct nfs4_lock_state *pos;
> list_for_each_entry(pos, &state->lock_states, ls_locks) {
> - if (pos->ls_owner != fl_owner)
> + if (pos->ls_owner != fl_owner &&
> + pos->ls_owner != fl_owner2)
> continue;
> atomic_inc(&pos->ls_count);
> return pos;
Ok, so we end up getting whatever is first on the list here. That's
certainly fine when there are either flock/OFD locks or traditional
POSIX locks in use.
When there are both in use though, then things may be less predictable.
That said, mixing flock/OFD and POSIX locks on the same fds from the
same process is not a great idea in general, and I have a hard time
coming up with a valid use-case there.
So, I don't see that as a real problem, but it may be worth explaining
that rationale in the comment block above this function in case we need
to revisit it later.
> @@ -857,7 +859,7 @@ static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_
>
> for(;;) {
> spin_lock(&state->state_lock);
> - lsp = __nfs4_find_lock_state(state, owner);
> + lsp = __nfs4_find_lock_state(state, owner, 0);
> if (lsp != NULL)
> break;
> if (new != NULL) {
> @@ -942,7 +944,7 @@ static int nfs4_copy_lock_stateid(nfs4_stateid *dst,
> const struct nfs_lock_context *l_ctx)
> {
> struct nfs4_lock_state *lsp;
> - fl_owner_t fl_owner;
> + fl_owner_t fl_owner, fl_flock_owner;
> int ret = -ENOENT;
>
> if (l_ctx == NULL)
> @@ -952,8 +954,10 @@ static int nfs4_copy_lock_stateid(nfs4_stateid *dst,
> goto out;
>
> fl_owner = l_ctx->lockowner.l_owner;
> + fl_flock_owner = l_ctx->open_context->flock_owner;
> +
> spin_lock(&state->state_lock);
> - lsp = __nfs4_find_lock_state(state, fl_owner);
> + lsp = __nfs4_find_lock_state(state, fl_owner, fl_flock_owner);
> if (lsp && test_bit(NFS_LOCK_LOST, &lsp->ls_flags))
> ret = -EIO;
> else if (lsp != NULL && test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags) != 0) {
>
>
> --
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--
Jeff Layton <jlayton@xxxxxxxxxx>
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