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xprtrdma: Improve locking around rpcrdma_rep destruction

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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>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
This commit is contained in:
Chuck Lever 2021-04-24 15:02:28 -04:00 • committed by Trond Myklebust
parent 5030c9a938
commit eaf86e8cc8
1 changed files with 24 additions and 7 deletions
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31
net/sunrpc/xprtrdma/verbs.c
View file

@ -1007,16 +1007,23 @@ out:
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_free(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_free(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_free(rep);
spin_lock(&buf->rb_lock);
}
spin_unlock(&buf->rb_lock);
}
/**