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authorPrakash Surya <[email protected]>2013-09-12 16:14:51 -0700
committerBrian Behlendorf <[email protected]>2013-10-16 14:48:35 -0700
commit56d40a686b0504042a088943154ba7b0dde36d51 (patch)
tree5d6d397d8e310874592909a7c17b453bb375b52c /module
parent4768c0d0a61497f2f3a52678154f2742a355618f (diff)
Add callbacks for displaying KSTAT_TYPE_RAW kstats
The current implementation for displaying kstats of type KSTAT_TYPE_RAW is rather crude. This patch attempts to enhance this handling by allowing a kstat user to register formatting callbacks which can optionally be used. The callbacks allow the user to implement functions for interpreting their data and transposing it into a character buffer. This buffer, containing a string representation of the raw data, is then be displayed through the current /proc textual interface. Additionally the kstats are made writable because it's now possible to provide a useful handler via the existing ks_update() interface. Signed-off-by: Prakash Surya <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Issue #296
Diffstat (limited to 'module')
-rw-r--r--module/spl/spl-kstat.c119
1 files changed, 105 insertions, 14 deletions
diff --git a/module/spl/spl-kstat.c b/module/spl/spl-kstat.c
index 4e900c066..57aabe2d0 100644
--- a/module/spl/spl-kstat.c
+++ b/module/spl/spl-kstat.c
@@ -41,10 +41,25 @@ static kmutex_t kstat_module_lock;
static struct list_head kstat_module_list;
static kid_t kstat_id;
-static void
+static int
+kstat_resize_raw(kstat_t *ksp)
+{
+ if (ksp->ks_raw_bufsize == KSTAT_RAW_MAX)
+ return ENOMEM;
+
+ vmem_free(ksp->ks_raw_buf, ksp->ks_raw_bufsize);
+ ksp->ks_raw_bufsize = MIN(ksp->ks_raw_bufsize * 2, KSTAT_RAW_MAX);
+ ksp->ks_raw_buf = vmem_alloc(ksp->ks_raw_bufsize, KM_SLEEP);
+
+ return 0;
+}
+
+static int
kstat_seq_show_headers(struct seq_file *f)
{
kstat_t *ksp = (kstat_t *)f->private;
+ int rc = 0;
+
ASSERT(ksp->ks_magic == KS_MAGIC);
seq_printf(f, "%d %d 0x%02x %d %d %lld %lld\n",
@@ -54,7 +69,17 @@ kstat_seq_show_headers(struct seq_file *f)
switch (ksp->ks_type) {
case KSTAT_TYPE_RAW:
- seq_printf(f, "raw data");
+restart:
+ if (ksp->ks_raw_ops.headers) {
+ rc = ksp->ks_raw_ops.headers(
+ ksp->ks_raw_buf, ksp->ks_raw_bufsize);
+ if (rc == ENOMEM && !kstat_resize_raw(ksp))
+ goto restart;
+ if (!rc)
+ seq_puts(f, ksp->ks_raw_buf);
+ } else {
+ seq_printf(f, "raw data\n");
+ }
break;
case KSTAT_TYPE_NAMED:
seq_printf(f, "%-31s %-4s %s\n",
@@ -92,6 +117,8 @@ kstat_seq_show_headers(struct seq_file *f)
default:
PANIC("Undefined kstat type %d\n", ksp->ks_type);
}
+
+ return -rc;
}
static int
@@ -232,9 +259,19 @@ kstat_seq_show(struct seq_file *f, void *p)
switch (ksp->ks_type) {
case KSTAT_TYPE_RAW:
- ASSERT(ksp->ks_ndata == 1);
- rc = kstat_seq_show_raw(f, ksp->ks_data,
- ksp->ks_data_size);
+restart:
+ if (ksp->ks_raw_ops.data) {
+ rc = ksp->ks_raw_ops.data(
+ ksp->ks_raw_buf, ksp->ks_raw_bufsize, p);
+ if (rc == ENOMEM && !kstat_resize_raw(ksp))
+ goto restart;
+ if (!rc)
+ seq_puts(f, ksp->ks_raw_buf);
+ } else {
+ ASSERT(ksp->ks_ndata == 1);
+ rc = kstat_seq_show_raw(f, ksp->ks_data,
+ ksp->ks_data_size);
+ }
break;
case KSTAT_TYPE_NAMED:
rc = kstat_seq_show_named(f, (kstat_named_t *)p);
@@ -255,13 +292,17 @@ kstat_seq_show(struct seq_file *f, void *p)
PANIC("Undefined kstat type %d\n", ksp->ks_type);
}
- return rc;
+ return -rc;
}
int
kstat_default_update(kstat_t *ksp, int rw)
{
ASSERT(ksp != NULL);
+
+ if (rw == KSTAT_WRITE)
+ return (EACCES);
+
return 0;
}
@@ -273,7 +314,10 @@ kstat_seq_data_addr(kstat_t *ksp, loff_t n)
switch (ksp->ks_type) {
case KSTAT_TYPE_RAW:
- rc = ksp->ks_data;
+ if (ksp->ks_raw_ops.addr)
+ rc = ksp->ks_raw_ops.addr(ksp, n);
+ else
+ rc = ksp->ks_data;
break;
case KSTAT_TYPE_NAMED:
rc = ksp->ks_data + n * sizeof(kstat_named_t);
@@ -307,13 +351,18 @@ kstat_seq_start(struct seq_file *f, loff_t *pos)
mutex_enter(&ksp->ks_lock);
+ if (ksp->ks_type == KSTAT_TYPE_RAW) {
+ ksp->ks_raw_bufsize = PAGE_SIZE;
+ ksp->ks_raw_buf = vmem_alloc(ksp->ks_raw_bufsize, KM_SLEEP);
+ }
+
/* Dynamically update kstat, on error existing kstats are used */
(void) ksp->ks_update(ksp, KSTAT_READ);
ksp->ks_snaptime = gethrtime();
- if (!n)
- kstat_seq_show_headers(f);
+ if (!n && kstat_seq_show_headers(f))
+ SRETURN(NULL);
if (n >= ksp->ks_ndata)
SRETURN(NULL);
@@ -341,6 +390,9 @@ kstat_seq_stop(struct seq_file *f, void *v)
kstat_t *ksp = (kstat_t *)f->private;
ASSERT(ksp->ks_magic == KS_MAGIC);
+ if (ksp->ks_type == KSTAT_TYPE_RAW)
+ vmem_free(ksp->ks_raw_buf, ksp->ks_raw_bufsize);
+
mutex_exit(&ksp->ks_lock);
}
@@ -408,13 +460,47 @@ proc_kstat_open(struct inode *inode, struct file *filp)
return rc;
}
+static ssize_t
+proc_kstat_write(struct file *filp, const char __user *buf,
+ size_t len, loff_t *ppos)
+{
+ struct seq_file *f = filp->private_data;
+ kstat_t *ksp = f->private;
+ int rc;
+
+ ASSERT(ksp->ks_magic == KS_MAGIC);
+
+ mutex_enter(ksp->ks_lock);
+ rc = ksp->ks_update(ksp, KSTAT_WRITE);
+ mutex_exit(ksp->ks_lock);
+
+ if (rc)
+ return (-rc);
+
+ *ppos += len;
+ return (len);
+}
+
static struct file_operations proc_kstat_operations = {
- .open = proc_kstat_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = seq_release,
+ .open = proc_kstat_open,
+ .write = proc_kstat_write,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
};
+void
+__kstat_set_raw_ops(kstat_t *ksp,
+ int (*headers)(char *buf, size_t size),
+ int (*data)(char *buf, size_t size, void *data),
+ void *(*addr)(kstat_t *ksp, loff_t index))
+{
+ ksp->ks_raw_ops.headers = headers;
+ ksp->ks_raw_ops.data = data;
+ ksp->ks_raw_ops.addr = addr;
+}
+EXPORT_SYMBOL(__kstat_set_raw_ops);
+
kstat_t *
__kstat_create(const char *ks_module, int ks_instance, const char *ks_name,
const char *ks_class, uchar_t ks_type, uint_t ks_ndata,
@@ -453,6 +539,11 @@ __kstat_create(const char *ks_module, int ks_instance, const char *ks_name,
ksp->ks_flags = ks_flags;
ksp->ks_update = kstat_default_update;
ksp->ks_private = NULL;
+ ksp->ks_raw_ops.headers = NULL;
+ ksp->ks_raw_ops.data = NULL;
+ ksp->ks_raw_ops.addr = NULL;
+ ksp->ks_raw_buf = NULL;
+ ksp->ks_raw_bufsize = 0;
switch (ksp->ks_type) {
case KSTAT_TYPE_RAW:
@@ -526,7 +617,7 @@ __kstat_install(kstat_t *ksp)
mutex_enter(&ksp->ks_lock);
ksp->ks_owner = module;
- ksp->ks_proc = proc_create_data(ksp->ks_name, 0444,
+ ksp->ks_proc = proc_create_data(ksp->ks_name, 0644,
module->ksm_proc, &proc_kstat_operations, (void *)ksp);
if (ksp->ks_proc == NULL) {
list_del_init(&ksp->ks_list);