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| author | Tom Tucker <tom@opengridcomputing.com> | 2009-01-05 15:21:19 -0600 |
|---|---|---|
| committer | J. Bruce Fields <bfields@citi.umich.edu> | 2009-01-07 17:08:46 -0500 |
| commit | 22945e4a1c7454c97f5d8aee1ef526c83fef3223 (patch) | |
| tree | f082143420da55b97c98a1534336b0cf03412e0b /net/sunrpc | |
| parent | 9a8d248e2d2e9c880ac4561f27fea5dc200655bd (diff) | |
| download | linux-22945e4a1c7454c97f5d8aee1ef526c83fef3223.tar.gz linux-22945e4a1c7454c97f5d8aee1ef526c83fef3223.tar.bz2 linux-22945e4a1c7454c97f5d8aee1ef526c83fef3223.zip | |
svc: Clean up deferred requests on transport destruction
A race between svc_revisit and svc_delete_xprt can result in
deferred requests holding references on a transport that can never be
recovered because dead transports are not enqueued for subsequent
processing.
Check for XPT_DEAD in revisit to clean up completing deferrals on a dead
transport and sweep a transport's deferred queue to do the same for queued
but unprocessed deferrals.
Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Diffstat (limited to 'net/sunrpc')
| -rw-r--r-- | net/sunrpc/svc_xprt.c | 25 |
1 files changed, 18 insertions, 7 deletions
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c index 29619612b9f1..a78b87937c73 100644 --- a/net/sunrpc/svc_xprt.c +++ b/net/sunrpc/svc_xprt.c @@ -850,6 +850,11 @@ static void svc_age_temp_xprts(unsigned long closure) void svc_delete_xprt(struct svc_xprt *xprt) { struct svc_serv *serv = xprt->xpt_server; + struct svc_deferred_req *dr; + + /* Only do this once */ + if (test_and_set_bit(XPT_DEAD, &xprt->xpt_flags)) + return; dprintk("svc: svc_delete_xprt(%p)\n", xprt); xprt->xpt_ops->xpo_detach(xprt); @@ -864,12 +869,16 @@ void svc_delete_xprt(struct svc_xprt *xprt) * while still attached to a queue, the queue itself * is about to be destroyed (in svc_destroy). */ - if (!test_and_set_bit(XPT_DEAD, &xprt->xpt_flags)) { - BUG_ON(atomic_read(&xprt->xpt_ref.refcount) < 2); - if (test_bit(XPT_TEMP, &xprt->xpt_flags)) - serv->sv_tmpcnt--; + if (test_bit(XPT_TEMP, &xprt->xpt_flags)) + serv->sv_tmpcnt--; + + for (dr = svc_deferred_dequeue(xprt); dr; + dr = svc_deferred_dequeue(xprt)) { svc_xprt_put(xprt); + kfree(dr); } + + svc_xprt_put(xprt); spin_unlock_bh(&serv->sv_lock); } @@ -915,17 +924,19 @@ static void svc_revisit(struct cache_deferred_req *dreq, int too_many) container_of(dreq, struct svc_deferred_req, handle); struct svc_xprt *xprt = dr->xprt; - if (too_many) { + spin_lock(&xprt->xpt_lock); + set_bit(XPT_DEFERRED, &xprt->xpt_flags); + if (too_many || test_bit(XPT_DEAD, &xprt->xpt_flags)) { + spin_unlock(&xprt->xpt_lock); + dprintk("revisit canceled\n"); svc_xprt_put(xprt); kfree(dr); return; } dprintk("revisit queued\n"); dr->xprt = NULL; - spin_lock(&xprt->xpt_lock); list_add(&dr->handle.recent, &xprt->xpt_deferred); spin_unlock(&xprt->xpt_lock); - set_bit(XPT_DEFERRED, &xprt->xpt_flags); svc_xprt_enqueue(xprt); svc_xprt_put(xprt); } |