Signed-off-by: Greg Banks <gnb@xxxxxxx>
---
net/sunrpc/cache.c | 116 ++++++++++++++++++++++++++++++++++++------
1 file changed, 100 insertions(+), 16 deletions(-)
Index: bfields/net/sunrpc/cache.c
===================================================================
--- bfields.orig/net/sunrpc/cache.c
+++ bfields/net/sunrpc/cache.c
@@ -109,6 +109,8 @@ static int cache_fresh_locked(struct cac
{
h->expiry_time = expiry;
h->last_refresh = get_seconds();
+ dprintk("%s: refreshing entry %p, expiry %ld refreshed %ld\n",
+ __func__, h, h->expiry_time, h->last_refresh);
return !test_and_set_bit(CACHE_VALID, &h->flags);
}
@@ -194,35 +196,57 @@ int cache_check(struct cache_detail *cd,
{
int rv;
long refresh_age, age;
+ long now = get_seconds();
+
+ dprintk("%s: cache %s entry %p\n",
+ __func__, cd->name, h);
/* First decide return status as best we can */
if (!test_bit(CACHE_VALID, &h->flags) ||
- h->expiry_time < get_seconds())
+ h->expiry_time < now) {
+ dprintk("%s: entry %p invalid, flags %lu expiry %ld now %ld\n",
+ __func__, h, h->flags, h->expiry_time, now);
rv = -EAGAIN;
- else if (cd->flush_time > h->last_refresh)
+ } else if (cd->flush_time > h->last_refresh) {
+ dprintk("%s: entry %p flushed: last_refresh %ld before flush_time %ld\n",
+ __func__, h, h->last_refresh, cd->flush_time);
rv = -EAGAIN;
- else {
+ } else {
/* entry is valid */
- if (test_bit(CACHE_NEGATIVE, &h->flags))
+ if (test_bit(CACHE_NEGATIVE, &h->flags)) {
+ dprintk("%s: entry %p negative\n",
+ __func__, h);
rv = -ENOENT;
+ }
else rv = 0;
}
/* now see if we want to start an upcall */
refresh_age = (h->expiry_time - h->last_refresh);
- age = get_seconds() - h->last_refresh;
+ age = now - h->last_refresh;
+ dprintk("%s: entry %p now=%ld expiry=%ld last_refresh=%ld refage=%ld age=%ld\n",
+ __func__, h, now, h->expiry_time, h->last_refresh, refresh_age, age);
if (rqstp == NULL) {
- if (rv == -EAGAIN)
+ if (rv == -EAGAIN) {
+ dprintk("%s: entry %p, needs upcall but cannot defer, returning -ENOENT\n",
+ __func__, h);
rv = -ENOENT;
+ }
} else if (rv == -EAGAIN || age > refresh_age/2) {
- dprintk("RPC: Want update, refage=%ld, age=%ld\n",
- refresh_age, age);
+ dprintk("%s: entry %p needs upcall\n",
+ __func__, h);
if (!test_and_set_bit(CACHE_PENDING, &h->flags)) {
+ dprintk("%s: entry %p initiating upcall\n",
+ __func__, h);
switch (cache_make_upcall(cd, h)) {
case -EINVAL:
+ dprintk("%s: entry %p cache_make_upcall returned -EINVAL\n",
+ __func__, h);
clear_bit(CACHE_PENDING, &h->flags);
if (rv == -EAGAIN) {
+ dprintk("%s: entry %p going NEGATIVE\n",
+ __func__, h);
set_bit(CACHE_NEGATIVE, &h->flags);
cache_fresh_unlocked(h, cd,
cache_fresh_locked(h, get_seconds()+CACHE_NEW_EXPIRY));
@@ -231,6 +255,8 @@ int cache_check(struct cache_detail *cd,
break;
case -EAGAIN:
+ dprintk("%s: entry %p cache_make_upcall returned -EAGAIN\n",
+ __func__, h);
clear_bit(CACHE_PENDING, &h->flags);
cache_revisit_request(h);
break;
@@ -244,6 +270,9 @@ int cache_check(struct cache_detail *cd,
if (rv)
cache_put(h, cd);
+
+ dprintk("%s: entry %p, returning %d\n",
+ __func__, h, rv);
return rv;
}
EXPORT_SYMBOL(cache_check);
@@ -559,10 +588,15 @@ static int cache_defer_req(struct cache_
struct cache_deferred_req *dreq;
int hash = DFR_HASH(h);
+ dprintk("%s: deferring entry %p\n",
+ __func__, h);
+
if (cache_defer_cnt >= DFR_MAX) {
/* too much in the cache, randomly drop this one,
* or continue and drop the oldest below
*/
+ dprintk("%s: entry %p, too many deferrals, dropping new\n",
+ __func__, h);
if (net_random()&1)
return -ETIMEDOUT;
}
@@ -585,6 +619,8 @@ static int cache_defer_req(struct cache_
if (++cache_defer_cnt > DFR_MAX) {
dreq = list_entry(cache_defer_list.prev,
struct cache_deferred_req, recent);
+ dprintk("%s: entry %p, too many deferrals, dropping old %p\n",
+ __func__, h, dreq);
list_del(&dreq->recent);
list_del(&dreq->hash);
cache_defer_cnt--;
@@ -610,6 +646,9 @@ static void cache_revisit_request(struct
struct list_head *lp;
int hash = DFR_HASH(h);
+ dprintk("%s: revisiting entry %p\n",
+ __func__, h);
+
INIT_LIST_HEAD(&pending);
spin_lock(&cache_defer_lock);
@@ -693,6 +732,9 @@ cache_read(struct file *filp, char __use
struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
int err;
+ dprintk("%s: cache %s pid %d(%s) reading %zd bytes\n",
+ __func__, cd->name, task_pid_nr(current), current->comm, count);
+
if (count == 0)
return 0;
@@ -704,17 +746,24 @@ cache_read(struct file *filp, char __use
}
spin_unlock(&cd->queue_lock);
- if (rq == NULL)
+ if (rq == NULL) {
+ dprintk("%s: cache %s no queued requests\n",
+ __func__, cd->name);
return 0; /* no queued requests */
+ }
err = -EAGAIN; /* gnb:TODO...this used to cause a loop, wtf */
if (!test_bit(CACHE_PENDING, &rq->item->flags))
goto error;
- /* gnb:TODO whine to dmesg; stat */
+ /* gnb:TODO stat */
err = -EFAULT;
- if (count < rq->len)
+ if (count < rq->len) {
+ dprintk("%s: cache %s short read, message length %d"
+ " dropping request %p entry %p\n",
+ __func__, cd->name, rq->len, rq, rq->item);
goto error; /* We make no pretence at handling short reads */
+ }
count = rq->len;
err = -EFAULT;
@@ -735,6 +784,7 @@ error:
/* need to release rq */
cache_request_put(rq, cd);
+ dprintk("%s: returning %d\n", __func__, err);
return err;
}
@@ -747,27 +797,38 @@ cache_write(struct file *filp, const cha
char *tmp;
int tmp_size = PAGE_SIZE;
+ dprintk("%s: cache %s pid %d(%s) writing %zd bytes\n",
+ __func__, cd->name, task_pid_nr(current), current->comm, count);
+
if (count == 0)
return 0;
+ err = -EINVAL;
if (count >= tmp_size)
- return -EINVAL;
+ goto out2;
+ err = -ENOMEM;
tmp = kmalloc(tmp_size, GFP_KERNEL);
if (!tmp)
- return -ENOMEM;
+ goto out2;
err = -EFAULT;
if (copy_from_user(tmp, buf, count))
goto out;
tmp[count] = '\0';
+ dprintk("%s: cache %s parsing update text \"%.*s\"\n",
+ __func__, cd->name, (int)count, tmp);
err = -EINVAL;
if (cd->cache_parse)
err = cd->cache_parse(cd, tmp, count);
out:
kfree(tmp);
- return err ? err : count;
+out2:
+ if (!err)
+ err = count;
+ dprintk("%s: returning %d\n", __func__, err);
+ return err;
}
static unsigned int
@@ -776,6 +837,9 @@ cache_poll(struct file *filp, poll_table
unsigned int mask = 0;
struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
+ dprintk("%s: cache %s pid %d(%s) polling on filp %p\n",
+ __func__, cd->name, task_pid_nr(current), current->comm, filp);
+
poll_wait(filp, &cd->queue_wait, wait);
if (filp->f_mode & FMODE_WRITE)
@@ -799,6 +863,9 @@ cache_ioctl(struct inode *ino, struct fi
struct cache_request *rq;
struct cache_detail *cd = PDE(ino)->data;
+ dprintk("%s: cache %s, cmd=%u\n",
+ __func__, cd->name, cmd);
+
if (cmd != FIONREAD)
return -EINVAL;
if (!(filp->f_mode & FMODE_READ))
@@ -811,6 +878,8 @@ cache_ioctl(struct inode *ino, struct fi
if (!list_empty(&cd->to_read)) {
rq = container_of(cd->to_read.next, struct cache_request, list);
len = rq->len;
+ dprintk("%s: cache %s, request %p is length %d\n",
+ __func__, cd->name, rq, rq->len);
}
spin_unlock(&cd->queue_lock);
@@ -870,6 +939,9 @@ static void cache_remove_queued(struct c
{
struct cache_request *rq;
+ dprintk("%s: trying to remove entry %p\n",
+ __func__, h);
+
/* find and de-queue */
spin_lock(&cd->queue_lock);
@@ -882,8 +954,11 @@ static void cache_remove_queued(struct c
spin_unlock(&cd->queue_lock);
/* if found, destroy */
- if (rq)
+ if (rq) {
+ dprintk("%s: dropping reference on entry %p\n",
+ __func__, h);
cache_request_put(rq, cd);
+ }
}
/*
@@ -992,6 +1067,9 @@ static int cache_make_upcall(struct cach
if (!rq)
return -EAGAIN;
+ dprintk("%s: entry %p, request %p\n",
+ __func__, h, rq);
+
bp = rq->buf;
len = rq->len;
cd->cache_request(cd, h, &bp, &len);
@@ -1001,6 +1079,10 @@ static int cache_make_upcall(struct cach
return -EAGAIN;
}
rq->len -= len;
+
+ dprintk("%s: cache %s, entry %p, queueing request %p text \"%.*s\"\n",
+ __func__, cd->name, h, rq, rq->len, rq->buf);
+
spin_lock(&cd->queue_lock);
list_add_tail(&rq->list, &cd->to_read);
spin_unlock(&cd->queue_lock);
--
--
Greg Banks, P.Engineer, SGI Australian Software Group.
the brightly coloured sporks of revolution.
I don't speak for SGI.
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