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FreeBSD: add support for KSTAT_TYPE_RAW
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A few kstats use KSTAT_TYPE_RAW to provide a string generated on
demand.  Implementing these as sysctls was punted until now.

Reviewed by: Toomas Soome <[email protected]>
Reviewed-by: Allan Jude <[email protected]>
Reviewed-by: Ryan Moeller <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Matt Macy <[email protected]>
Closes openzfs#10836
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@mattmacy
mattmacy authored Aug 30, 2020
1 parent 3e29e19 commit d436de6
Showing 1 changed file with 128 additions and 17 deletions.
145 changes: 128 additions & 17 deletions module/os/freebsd/spl/spl_kstat.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -34,6 +34,7 @@ __FBSDID("$FreeBSD$");
#include <sys/malloc.h>
#include <sys/sysctl.h>
#include <sys/kstat.h>
#include <sys/sbuf.h>

static MALLOC_DEFINE(M_KSTAT, "kstat_data", "Kernel statistics");

Expand Down Expand Up @@ -61,6 +62,91 @@ kstat_default_update(kstat_t *ksp, int rw)
return (0);
}

static int
kstat_resize_raw(kstat_t *ksp)
{
if (ksp->ks_raw_bufsize == KSTAT_RAW_MAX)
return (ENOMEM);

free(ksp->ks_raw_buf, M_TEMP);
ksp->ks_raw_bufsize = MIN(ksp->ks_raw_bufsize * 2, KSTAT_RAW_MAX);
ksp->ks_raw_buf = malloc(ksp->ks_raw_bufsize, M_TEMP, M_WAITOK);

return (0);
}

static void *
kstat_raw_default_addr(kstat_t *ksp, loff_t n)
{
if (n == 0)
return (ksp->ks_data);
return (NULL);
}


static int
kstat_sysctl_raw(SYSCTL_HANDLER_ARGS)
{
struct sbuf *sb;
void *data;
kstat_t *ksp = arg1;
void *(*addr_op)(kstat_t *ksp, loff_t index);
int n, rc = 0;

sb = sbuf_new_auto();
if (sb == NULL)
return (ENOMEM);

if (ksp->ks_raw_ops.addr)
addr_op = ksp->ks_raw_ops.addr;
else
addr_op = kstat_raw_default_addr;

mutex_enter(ksp->ks_lock);

/* Update the aggsums before reading */
(void) ksp->ks_update(ksp, KSTAT_READ);

ksp->ks_raw_bufsize = PAGE_SIZE;
ksp->ks_raw_buf = malloc(PAGE_SIZE, M_TEMP, M_WAITOK);

n = 0;
restart_headers:
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_headers;
if (rc == 0)
sbuf_printf(sb, "%s", ksp->ks_raw_buf);
}

while ((data = addr_op(ksp, n)) != NULL) {
restart:
if (ksp->ks_raw_ops.data) {
rc = ksp->ks_raw_ops.data(ksp->ks_raw_buf,
ksp->ks_raw_bufsize, data);
if (rc == ENOMEM && !kstat_resize_raw(ksp))
goto restart;
if (rc == 0)
sbuf_printf(sb, "%s", ksp->ks_raw_buf);

} else {
ASSERT(ksp->ks_ndata == 1);
sbuf_hexdump(sb, ksp->ks_data,
ksp->ks_data_size, NULL, 0);
}
n++;
}
free(ksp->ks_raw_buf, M_TEMP);
mutex_exit(ksp->ks_lock);
rc = sbuf_finish(sb);
if (rc == 0)
rc = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb));
sbuf_delete(sb);
return (rc);
}

kstat_t *
__kstat_create(const char *module, int instance, const char *name,
const char *class, uchar_t ks_type, uint_t ks_ndata, uchar_t flags)
Expand Down Expand Up @@ -88,6 +174,9 @@ __kstat_create(const char *module, int instance, const char *name,
ksp->ks_flags = flags;
ksp->ks_update = kstat_default_update;

mutex_init(&ksp->ks_private_lock, NULL, MUTEX_DEFAULT, NULL);
ksp->ks_lock = &ksp->ks_private_lock;

switch (ksp->ks_type) {
case KSTAT_TYPE_RAW:
ksp->ks_ndata = 1;
Expand Down Expand Up @@ -146,14 +235,18 @@ __kstat_create(const char *module, int instance, const char *name,
free(ksp, M_KSTAT);
return (NULL);
}
root = SYSCTL_ADD_NODE(&ksp->ks_sysctl_ctx, SYSCTL_CHILDREN(root),
OID_AUTO, name, CTLFLAG_RW, 0, "");
if (root == NULL) {
printf("%s: Cannot create kstat.%s.%s.%s tree!\n", __func__,
module, class, name);
sysctl_ctx_free(&ksp->ks_sysctl_ctx);
free(ksp, M_KSTAT);
return (NULL);
if (ksp->ks_type != KSTAT_TYPE_RAW) {
root = SYSCTL_ADD_NODE(&ksp->ks_sysctl_ctx,
SYSCTL_CHILDREN(root),
OID_AUTO, name, CTLFLAG_RW, 0, "");
if (root == NULL) {
printf("%s: Cannot create kstat.%s.%s.%s tree!\n",
__func__, module, class, name);
sysctl_ctx_free(&ksp->ks_sysctl_ctx);
free(ksp, M_KSTAT);
return (NULL);
}

}
ksp->ks_sysctl_root = root;

Expand All @@ -164,9 +257,10 @@ static int
kstat_sysctl(SYSCTL_HANDLER_ARGS)
{
kstat_t *ksp = arg1;
kstat_named_t *ksent = ksp->ks_data;
kstat_named_t *ksent;
uint64_t val;

ksent = ksp->ks_data;
/* Select the correct element */
ksent += arg2;
/* Update the aggsums before reading */
Expand Down Expand Up @@ -198,23 +292,38 @@ kstat_sysctl_string(SYSCTL_HANDLER_ARGS)
void
kstat_install(kstat_t *ksp)
{
struct sysctl_oid *root;
kstat_named_t *ksent;
char *namelast;
int typelast;

ksent = ksp->ks_data;
if (ksp->ks_ndata == UINT32_MAX) {
#ifdef INVARIANTS
printf("can't handle raw ops yet!!!\n");
#endif
return;
}
if (ksent == NULL) {
printf("%s ksp->ks_data == NULL!!!!\n", __func__);
if (ksp->ks_ndata == UINT32_MAX)
VERIFY(ksp->ks_type == KSTAT_TYPE_RAW);
if (ksp->ks_type == KSTAT_TYPE_RAW) {
if (ksp->ks_raw_ops.data) {
root = SYSCTL_ADD_PROC(&ksp->ks_sysctl_ctx,
SYSCTL_CHILDREN(ksp->ks_sysctl_root),
OID_AUTO, ksp->ks_name,
CTLTYPE_STRING | CTLFLAG_RD, ksp, 0,
kstat_sysctl_raw, "A", ksp->ks_name);
} else {
root = SYSCTL_ADD_PROC(&ksp->ks_sysctl_ctx,
SYSCTL_CHILDREN(ksp->ks_sysctl_root),
OID_AUTO, ksp->ks_name,
CTLTYPE_OPAQUE | CTLFLAG_RD, ksp, 0,
kstat_sysctl_raw, "", ksp->ks_name);
}
VERIFY(root != NULL);
ksp->ks_sysctl_root = root;
return;
}

VERIFY((ksp->ks_flags & KSTAT_FLAG_VIRTUAL) || ksent != NULL);

typelast = 0;
namelast = NULL;

for (int i = 0; i < ksp->ks_ndata; i++, ksent++) {
if (ksent->data_type != 0) {
typelast = ksent->data_type;
Expand Down Expand Up @@ -285,6 +394,8 @@ kstat_delete(kstat_t *ksp)
{

sysctl_ctx_free(&ksp->ks_sysctl_ctx);
ksp->ks_lock = NULL;
mutex_destroy(&ksp->ks_private_lock);
free(ksp, M_KSTAT);
}

Expand Down

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