Commit 007f7383 authored by Neil Brown's avatar Neil Brown Committed by Linus Torvalds

[PATCH] knfsd: Allow rpcsvc caches to provide a 'cache_show' method

This provides a /proc/sunrpc/*/content seq_file for caches to display
their content.

This code is based on the code for /proc/fs/nfs/exports
parent f5a99512
......@@ -78,6 +78,11 @@ struct cache_detail {
int (*cache_parse)(struct cache_detail *,
char *buf, int len);
int (*cache_show)(struct seq_file *m,
struct cache_detail *cd,
struct cache_head *h,
char *pbuf);
/* fields below this comment are for internal use
* and should not be touched by cache owners
*/
......
......@@ -22,6 +22,7 @@
#include <linux/ctype.h>
#include <asm/uaccess.h>
#include <linux/poll.h>
#include <linux/seq_file.h>
#include <linux/proc_fs.h>
#include <linux/net.h>
#include <asm/ioctls.h>
......@@ -160,7 +161,8 @@ static spinlock_t cache_list_lock = SPIN_LOCK_UNLOCKED;
static struct cache_detail *current_detail;
static int current_index;
struct file_operations cache_file_operations;
static struct file_operations cache_file_operations;
static struct file_operations content_file_operations;
void cache_register(struct cache_detail *cd)
{
......@@ -169,6 +171,7 @@ void cache_register(struct cache_detail *cd)
struct proc_dir_entry *p;
cd->proc_ent->owner = THIS_MODULE;
if (cd->cache_request || cd->cache_parse) {
p = create_proc_entry("channel", S_IFREG|S_IRUSR|S_IWUSR,
cd->proc_ent);
if (p) {
......@@ -177,6 +180,16 @@ void cache_register(struct cache_detail *cd)
p->data = cd;
}
}
if (cd->cache_show) {
p = create_proc_entry("content", S_IFREG|S_IRUSR|S_IWUSR,
cd->proc_ent);
if (p) {
p->proc_fops = &content_file_operations;
p->owner = THIS_MODULE;
p->data = cd;
}
}
}
rwlock_init(&cd->hash_lock);
INIT_LIST_HEAD(&cd->queue);
spin_lock(&cache_list_lock);
......@@ -710,7 +723,7 @@ cache_release(struct inode *inode, struct file *filp)
struct file_operations cache_file_operations = {
static struct file_operations cache_file_operations = {
.llseek = no_llseek,
.read = cache_read,
.write = cache_write,
......@@ -927,3 +940,146 @@ int qword_get(char **bpp, char *dest, int bufsize)
*dest = '\0';
return len;
}
/*
* support /proc/sunrpc/cache/$CACHENAME/content
* as a seqfile.
* We call ->cache_show passing NULL for the item to
* get a header, then pass each real item in the cache
*/
struct handle {
struct cache_detail *cd;
char *pbuf;
};
static void *c_start(struct seq_file *m, loff_t *pos)
{
loff_t n = *pos;
unsigned hash, entry;
struct cache_head *ch;
struct cache_detail *cd = ((struct handle*)m->private)->cd;
read_lock(&cd->hash_lock);
if (!n--)
return (void *)1;
hash = n >> 32;
entry = n & ((1LL<<32) - 1);
for (ch=cd->hash_table[hash]; ch; ch=ch->next)
if (!entry--)
return ch;
n &= ~((1LL<<32) - 1);
do {
hash++;
n += 1LL<<32;
} while(hash < cd->hash_size &&
cd->hash_table[hash]==NULL);
if (hash >= cd->hash_size)
return NULL;
*pos = n+1;
return cd->hash_table[hash];
}
static void *c_next(struct seq_file *m, void *p, loff_t *pos)
{
struct cache_head *ch = p;
int hash = (*pos >> 32);
struct cache_detail *cd = ((struct handle*)m->private)->cd;
if (p == (void *)1)
hash = 0;
else if (ch->next == NULL) {
hash++;
*pos += 1LL<<32;
} else {
++*pos;
return ch->next;
}
*pos &= ~((1LL<<32) - 1);
while (hash < cd->hash_size &&
cd->hash_table[hash] == NULL) {
hash++;
*pos += 1LL<<32;
}
if (hash >= cd->hash_size)
return NULL;
++*pos;
return cd->hash_table[hash];
}
static void c_stop(struct seq_file *m, void *p)
{
struct cache_detail *cd = ((struct handle*)m->private)->cd;
read_unlock(&cd->hash_lock);
}
static int c_show(struct seq_file *m, void *p)
{
struct cache_head *cp = p;
struct cache_detail *cd = ((struct handle*)m->private)->cd;
char *pbuf = ((struct handle*)m->private)->pbuf;
if (p == (void *)1)
return cd->cache_show(m, cd, NULL, pbuf);
cache_get(cp);
if (cache_check(cd, cp, NULL))
return 0;
cache_put(cp, cd);
return cd->cache_show(m, cd, cp, pbuf);
}
struct seq_operations cache_content_op = {
.start = c_start,
.next = c_next,
.stop = c_stop,
.show = c_show,
};
static int content_open(struct inode *inode, struct file *file)
{
int res;
char *namebuf = kmalloc(PAGE_SIZE, GFP_KERNEL);
struct handle *han;
struct cache_detail *cd = PDE(inode)->data;
if (namebuf == NULL)
return -ENOMEM;
han = kmalloc(sizeof(*han), GFP_KERNEL);
if (han == NULL) {
kfree(namebuf);
return -ENOMEM;
}
han->pbuf = namebuf;
han->cd = cd;
res = seq_open(file, &cache_content_op);
if (res) {
kfree(namebuf);
kfree(han);
} else
((struct seq_file *)file->private_data)->private = han;
return res;
}
static int content_release(struct inode *inode, struct file *file)
{
struct seq_file *m = (struct seq_file *)file->private_data;
struct handle *han = m->private;
kfree(han->pbuf);
kfree(han);
m->private = NULL;
return seq_release(inode, file);
}
static struct file_operations content_file_operations = {
.open = content_open,
.read = seq_read,
.llseek = seq_lseek,
.release = content_release,
};
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