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lockd: define host_for_each{_safe} macros
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We've got a lot of loops like this, and I find them a little easier to
read with the macros.  More such loops are coming.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
[ cel: Forward-ported to 2.6.37 ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
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J. Bruce Fields authored and Trond Myklebust committed Dec 16, 2010
1 parent bf26955 commit b113746
Showing 1 changed file with 55 additions and 52 deletions.
107 changes: 55 additions & 52 deletions fs/lockd/host.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -26,6 +26,18 @@
#define NLM_HOST_COLLECT (120 * HZ)

static struct hlist_head nlm_hosts[NLM_HOST_NRHASH];

#define for_each_host(host, pos, chain, table) \
for ((chain) = (table); \
(chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \
hlist_for_each_entry((host), (pos), (chain), h_hash)

#define for_each_host_safe(host, pos, next, chain, table) \
for ((chain) = (table); \
(chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \
hlist_for_each_entry_safe((host), (pos), (next), \
(chain), h_hash)

static unsigned long next_gc;
static int nrhosts;
static DEFINE_MUTEX(nlm_host_mutex);
Expand Down Expand Up @@ -453,28 +465,26 @@ void nlm_host_rebooted(const struct nlm_reboot *info)
* To avoid processing a host several times, we match the nsmstate.
*/
again: mutex_lock(&nlm_host_mutex);
for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
hlist_for_each_entry(host, pos, chain, h_hash) {
if (host->h_nsmhandle == nsm
&& host->h_nsmstate != info->state) {
host->h_nsmstate = info->state;
host->h_state++;

nlm_get_host(host);
mutex_unlock(&nlm_host_mutex);

if (host->h_server) {
/* We're server for this guy, just ditch
* all the locks he held. */
nlmsvc_free_host_resources(host);
} else {
/* He's the server, initiate lock recovery. */
nlmclnt_recovery(host);
}

nlm_release_host(host);
goto again;
for_each_host(host, pos, chain, nlm_hosts) {
if (host->h_nsmhandle == nsm
&& host->h_nsmstate != info->state) {
host->h_nsmstate = info->state;
host->h_state++;

nlm_get_host(host);
mutex_unlock(&nlm_host_mutex);

if (host->h_server) {
/* We're server for this guy, just ditch
* all the locks he held. */
nlmsvc_free_host_resources(host);
} else {
/* He's the server, initiate lock recovery. */
nlmclnt_recovery(host);
}

nlm_release_host(host);
goto again;
}
}
mutex_unlock(&nlm_host_mutex);
Expand All @@ -497,13 +507,11 @@ nlm_shutdown_hosts(void)

/* First, make all hosts eligible for gc */
dprintk("lockd: nuking all hosts...\n");
for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
hlist_for_each_entry(host, pos, chain, h_hash) {
host->h_expires = jiffies - 1;
if (host->h_rpcclnt) {
rpc_shutdown_client(host->h_rpcclnt);
host->h_rpcclnt = NULL;
}
for_each_host(host, pos, chain, nlm_hosts) {
host->h_expires = jiffies - 1;
if (host->h_rpcclnt) {
rpc_shutdown_client(host->h_rpcclnt);
host->h_rpcclnt = NULL;
}
}

Expand All @@ -515,12 +523,10 @@ nlm_shutdown_hosts(void)
if (nrhosts) {
printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
dprintk("lockd: %d hosts left:\n", nrhosts);
for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
hlist_for_each_entry(host, pos, chain, h_hash) {
dprintk(" %s (cnt %d use %d exp %ld)\n",
host->h_name, atomic_read(&host->h_count),
host->h_inuse, host->h_expires);
}
for_each_host(host, pos, chain, nlm_hosts) {
dprintk(" %s (cnt %d use %d exp %ld)\n",
host->h_name, atomic_read(&host->h_count),
host->h_inuse, host->h_expires);
}
}
}
Expand All @@ -538,29 +544,26 @@ nlm_gc_hosts(void)
struct nlm_host *host;

dprintk("lockd: host garbage collection\n");
for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
hlist_for_each_entry(host, pos, chain, h_hash)
host->h_inuse = 0;
}
for_each_host(host, pos, chain, nlm_hosts)
host->h_inuse = 0;

/* Mark all hosts that hold locks, blocks or shares */
nlmsvc_mark_resources();

for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
hlist_for_each_entry_safe(host, pos, next, chain, h_hash) {
if (atomic_read(&host->h_count) || host->h_inuse
|| time_before(jiffies, host->h_expires)) {
dprintk("nlm_gc_hosts skipping %s (cnt %d use %d exp %ld)\n",
host->h_name, atomic_read(&host->h_count),
host->h_inuse, host->h_expires);
continue;
}
dprintk("lockd: delete host %s\n", host->h_name);
hlist_del_init(&host->h_hash);

nlm_destroy_host(host);
nrhosts--;
for_each_host_safe(host, pos, next, chain, nlm_hosts) {
if (atomic_read(&host->h_count) || host->h_inuse
|| time_before(jiffies, host->h_expires)) {
dprintk("nlm_gc_hosts skipping %s "
"(cnt %d use %d exp %ld)\n",
host->h_name, atomic_read(&host->h_count),
host->h_inuse, host->h_expires);
continue;
}
dprintk("lockd: delete host %s\n", host->h_name);
hlist_del_init(&host->h_hash);

nlm_destroy_host(host);
nrhosts--;
}

next_gc = jiffies + NLM_HOST_COLLECT;
Expand Down

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