| Message ID | 161885534259.38598.17355600080366820390.stgit@manet.1015granger.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | NFS/RDMA client patches for next | expand |
On Mon, 2021-04-19 at 14:02 -0400, Chuck Lever wrote: > Currently rpcrdma_reps_destroy() assumes that, at transport > tear-down, the content of the rb_free_reps list is the same as the > content of the rb_all_reps list. Although that is usually true, > using the rb_all_reps list should be more reliable because of > the way it's managed. And, rpcrdma_reps_unmap() uses rb_all_reps; > these two functions should both traverse the "all" list. > > Ensure that all rpcrdma_reps are always destroyed whether they are > on the rep free list or not. > > Signed-off-by: Chuck Lever <chuck.lever@oracle.com> > --- > net/sunrpc/xprtrdma/verbs.c | 31 ++++++++++++++++++++++++------- > 1 file changed, 24 insertions(+), 7 deletions(-) > > diff --git a/net/sunrpc/xprtrdma/verbs.c > b/net/sunrpc/xprtrdma/verbs.c > index 1b599a623eea..482fdc9e25c2 100644 > --- a/net/sunrpc/xprtrdma/verbs.c > +++ b/net/sunrpc/xprtrdma/verbs.c > @@ -1007,16 +1007,23 @@ struct rpcrdma_rep *rpcrdma_rep_create(struct > rpcrdma_xprt *r_xprt, > return NULL; > } > > -/* No locking needed here. This function is invoked only by the > - * Receive completion handler, or during transport shutdown. > - */ > -static void rpcrdma_rep_destroy(struct rpcrdma_rep *rep) > +static void rpcrdma_rep_destroy_locked(struct rpcrdma_rep *rep) The name here is extremely confusing. As far as I can tell, this isn't called with any lock? > { > - list_del(&rep->rr_all); > rpcrdma_regbuf_free(rep->rr_rdmabuf); > kfree(rep); > } > > +static void rpcrdma_rep_destroy(struct rpcrdma_rep *rep) > +{ > + struct rpcrdma_buffer *buf = &rep->rr_rxprt->rx_buf; > + > + spin_lock(&buf->rb_lock); > + list_del(&rep->rr_all); > + spin_unlock(&buf->rb_lock); > + > + rpcrdma_rep_destroy_locked(rep); > +} > + > static struct rpcrdma_rep *rpcrdma_rep_get_locked(struct > rpcrdma_buffer *buf) > { > struct llist_node *node; > @@ -1049,8 +1056,18 @@ static void rpcrdma_reps_destroy(struct > rpcrdma_buffer *buf) > { > struct rpcrdma_rep *rep; > > - while ((rep = rpcrdma_rep_get_locked(buf)) != NULL) > - rpcrdma_rep_destroy(rep); > + spin_lock(&buf->rb_lock); > + while ((rep = list_first_entry_or_null(&buf->rb_all_reps, > + struct rpcrdma_rep, > + rr_all)) != NULL) { > + list_del(&rep->rr_all); > + spin_unlock(&buf->rb_lock); > + > + rpcrdma_rep_destroy_locked(rep); > + > + spin_lock(&buf->rb_lock); > + } > + spin_unlock(&buf->rb_lock); > } > > /** > >
> On Apr 23, 2021, at 5:06 PM, Trond Myklebust <trondmy@hammerspace.com> wrote: > > On Mon, 2021-04-19 at 14:02 -0400, Chuck Lever wrote: >> Currently rpcrdma_reps_destroy() assumes that, at transport >> tear-down, the content of the rb_free_reps list is the same as the >> content of the rb_all_reps list. Although that is usually true, >> using the rb_all_reps list should be more reliable because of >> the way it's managed. And, rpcrdma_reps_unmap() uses rb_all_reps; >> these two functions should both traverse the "all" list. >> >> Ensure that all rpcrdma_reps are always destroyed whether they are >> on the rep free list or not. >> >> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> >> --- >> net/sunrpc/xprtrdma/verbs.c | 31 ++++++++++++++++++++++++------- >> 1 file changed, 24 insertions(+), 7 deletions(-) >> >> diff --git a/net/sunrpc/xprtrdma/verbs.c >> b/net/sunrpc/xprtrdma/verbs.c >> index 1b599a623eea..482fdc9e25c2 100644 >> --- a/net/sunrpc/xprtrdma/verbs.c >> +++ b/net/sunrpc/xprtrdma/verbs.c >> @@ -1007,16 +1007,23 @@ struct rpcrdma_rep *rpcrdma_rep_create(struct >> rpcrdma_xprt *r_xprt, >> return NULL; >> } >> >> -/* No locking needed here. This function is invoked only by the >> - * Receive completion handler, or during transport shutdown. >> - */ >> -static void rpcrdma_rep_destroy(struct rpcrdma_rep *rep) >> +static void rpcrdma_rep_destroy_locked(struct rpcrdma_rep *rep) > > The name here is extremely confusing. As far as I can tell, this isn't > called with any lock? Fair enough. I renamed it rpcrdma_rep_free() and it doesn't seem to have any consequences for downstream commits in this series. You could do a global edit, I can resend you this patch with the change, or I can post a v4 of this series. Let me know your preference. >> { >> - list_del(&rep->rr_all); >> rpcrdma_regbuf_free(rep->rr_rdmabuf); >> kfree(rep); >> } >> >> +static void rpcrdma_rep_destroy(struct rpcrdma_rep *rep) >> +{ >> + struct rpcrdma_buffer *buf = &rep->rr_rxprt->rx_buf; >> + >> + spin_lock(&buf->rb_lock); >> + list_del(&rep->rr_all); >> + spin_unlock(&buf->rb_lock); >> + >> + rpcrdma_rep_destroy_locked(rep); >> +} >> + >> static struct rpcrdma_rep *rpcrdma_rep_get_locked(struct >> rpcrdma_buffer *buf) >> { >> struct llist_node *node; >> @@ -1049,8 +1056,18 @@ static void rpcrdma_reps_destroy(struct >> rpcrdma_buffer *buf) >> { >> struct rpcrdma_rep *rep; >> >> - while ((rep = rpcrdma_rep_get_locked(buf)) != NULL) >> - rpcrdma_rep_destroy(rep); >> + spin_lock(&buf->rb_lock); >> + while ((rep = list_first_entry_or_null(&buf->rb_all_reps, >> + struct rpcrdma_rep, >> + rr_all)) != NULL) { >> + list_del(&rep->rr_all); >> + spin_unlock(&buf->rb_lock); >> + >> + rpcrdma_rep_destroy_locked(rep); >> + >> + spin_lock(&buf->rb_lock); >> + } >> + spin_unlock(&buf->rb_lock); >> } >> >> /** >> >> > > -- > Trond Myklebust > Linux NFS client maintainer, Hammerspace > trond.myklebust@hammerspace.com -- Chuck Lever
On Sat, 2021-04-24 at 17:39 +0000, Chuck Lever III wrote: > > > > On Apr 23, 2021, at 5:06 PM, Trond Myklebust < > > trondmy@hammerspace.com> wrote: > > > > On Mon, 2021-04-19 at 14:02 -0400, Chuck Lever wrote: > > > Currently rpcrdma_reps_destroy() assumes that, at transport > > > tear-down, the content of the rb_free_reps list is the same as > > > the > > > content of the rb_all_reps list. Although that is usually true, > > > using the rb_all_reps list should be more reliable because of > > > the way it's managed. And, rpcrdma_reps_unmap() uses rb_all_reps; > > > these two functions should both traverse the "all" list. > > > > > > Ensure that all rpcrdma_reps are always destroyed whether they > > > are > > > on the rep free list or not. > > > > > > Signed-off-by: Chuck Lever <chuck.lever@oracle.com> > > > --- > > > net/sunrpc/xprtrdma/verbs.c | 31 ++++++++++++++++++++++++----- > > > -- > > > 1 file changed, 24 insertions(+), 7 deletions(-) > > > > > > diff --git a/net/sunrpc/xprtrdma/verbs.c > > > b/net/sunrpc/xprtrdma/verbs.c > > > index 1b599a623eea..482fdc9e25c2 100644 > > > --- a/net/sunrpc/xprtrdma/verbs.c > > > +++ b/net/sunrpc/xprtrdma/verbs.c > > > @@ -1007,16 +1007,23 @@ struct rpcrdma_rep > > > *rpcrdma_rep_create(struct > > > rpcrdma_xprt *r_xprt, > > > return NULL; > > > } > > > > > > -/* No locking needed here. This function is invoked only by the > > > - * Receive completion handler, or during transport shutdown. > > > - */ > > > -static void rpcrdma_rep_destroy(struct rpcrdma_rep *rep) > > > +static void rpcrdma_rep_destroy_locked(struct rpcrdma_rep *rep) > > > > The name here is extremely confusing. As far as I can tell, this > > isn't > > called with any lock? > > Fair enough. > > I renamed it rpcrdma_rep_free() and it doesn't seem to have > any consequences for downstream commits in this series. Sounds good. > > You could do a global edit, I can resend you this patch with > the change, or I can post a v4 of this series. Let me know > your preference. > Can you please just resend this patch with the update, unless there are repercussions for the other patches? (in which case a v4 would be welcome) > > > > { > > > - list_del(&rep->rr_all); > > > rpcrdma_regbuf_free(rep->rr_rdmabuf); > > > kfree(rep); > > > } > > > > > > +static void rpcrdma_rep_destroy(struct rpcrdma_rep *rep) > > > +{ > > > + struct rpcrdma_buffer *buf = &rep->rr_rxprt->rx_buf; > > > + > > > + spin_lock(&buf->rb_lock); > > > + list_del(&rep->rr_all); > > > + spin_unlock(&buf->rb_lock); > > > + > > > + rpcrdma_rep_destroy_locked(rep); > > > +} > > > + > > > static struct rpcrdma_rep *rpcrdma_rep_get_locked(struct > > > rpcrdma_buffer *buf) > > > { > > > struct llist_node *node; > > > @@ -1049,8 +1056,18 @@ static void rpcrdma_reps_destroy(struct > > > rpcrdma_buffer *buf) > > > { > > > struct rpcrdma_rep *rep; > > > > > > - while ((rep = rpcrdma_rep_get_locked(buf)) != NULL) > > > - rpcrdma_rep_destroy(rep); > > > + spin_lock(&buf->rb_lock); > > > + while ((rep = list_first_entry_or_null(&buf->rb_all_reps, > > > + struct > > > rpcrdma_rep, > > > + rr_all)) != NULL) > > > { > > > + list_del(&rep->rr_all); > > > + spin_unlock(&buf->rb_lock); > > > + > > > + rpcrdma_rep_destroy_locked(rep); > > > + > > > + spin_lock(&buf->rb_lock); > > > + } > > > + spin_unlock(&buf->rb_lock); > > > } > > > > > > /** > > > > > > > > > > -- > > Trond Myklebust > > Linux NFS client maintainer, Hammerspace > > trond.myklebust@hammerspace.com > > -- > Chuck Lever > > >
diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c index 1b599a623eea..482fdc9e25c2 100644 --- a/net/sunrpc/xprtrdma/verbs.c +++ b/net/sunrpc/xprtrdma/verbs.c @@ -1007,16 +1007,23 @@ struct rpcrdma_rep *rpcrdma_rep_create(struct rpcrdma_xprt *r_xprt, return NULL; } -/* No locking needed here. This function is invoked only by the - * Receive completion handler, or during transport shutdown. - */ -static void rpcrdma_rep_destroy(struct rpcrdma_rep *rep) +static void rpcrdma_rep_destroy_locked(struct rpcrdma_rep *rep) { - list_del(&rep->rr_all); rpcrdma_regbuf_free(rep->rr_rdmabuf); kfree(rep); } +static void rpcrdma_rep_destroy(struct rpcrdma_rep *rep) +{ + struct rpcrdma_buffer *buf = &rep->rr_rxprt->rx_buf; + + spin_lock(&buf->rb_lock); + list_del(&rep->rr_all); + spin_unlock(&buf->rb_lock); + + rpcrdma_rep_destroy_locked(rep); +} + static struct rpcrdma_rep *rpcrdma_rep_get_locked(struct rpcrdma_buffer *buf) { struct llist_node *node; @@ -1049,8 +1056,18 @@ static void rpcrdma_reps_destroy(struct rpcrdma_buffer *buf) { struct rpcrdma_rep *rep; - while ((rep = rpcrdma_rep_get_locked(buf)) != NULL) - rpcrdma_rep_destroy(rep); + spin_lock(&buf->rb_lock); + while ((rep = list_first_entry_or_null(&buf->rb_all_reps, + struct rpcrdma_rep, + rr_all)) != NULL) { + list_del(&rep->rr_all); + spin_unlock(&buf->rb_lock); + + rpcrdma_rep_destroy_locked(rep); + + spin_lock(&buf->rb_lock); + } + spin_unlock(&buf->rb_lock); } /**
Currently rpcrdma_reps_destroy() assumes that, at transport tear-down, the content of the rb_free_reps list is the same as the content of the rb_all_reps list. Although that is usually true, using the rb_all_reps list should be more reliable because of the way it's managed. And, rpcrdma_reps_unmap() uses rb_all_reps; these two functions should both traverse the "all" list. Ensure that all rpcrdma_reps are always destroyed whether they are on the rep free list or not. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> --- net/sunrpc/xprtrdma/verbs.c | 31 ++++++++++++++++++++++++------- 1 file changed, 24 insertions(+), 7 deletions(-)