Register correct handlers in nvlist_alloc()

The non-blocking allocation handlers in nvlist_alloc() would be
mistakenly assigned if any flags other than KM_SLEEP were passed.
This meant that nvlists allocated with KM_PUSHPUSH or other KM_*
debug flags were effectively always using atomic allocations.

While these failures were unlikely it could lead to assertions
because KM_PUSHPAGE allocations in particular are guaranteed to
succeed or block.  They must never fail.

Since the existing API does not allow us to pass allocation
flags to the private allocators the cleanest thing to do is to
add a KM_PUSHPAGE allocator.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes zfsonlinux/spl#249
This commit is contained in:
Brian Behlendorf 2013-06-18 10:15:33 -07:00
parent df4474f92d
commit 81eaf15107
3 changed files with 38 additions and 4 deletions

View File

@ -144,6 +144,7 @@ extern nv_alloc_t *nv_alloc_nosleep;
#if defined(_KERNEL) && !defined(_BOOT)
extern nv_alloc_t *nv_alloc_sleep;
extern nv_alloc_t *nv_alloc_pushpage;
#endif
int nv_alloc_init(nv_alloc_t *, const nv_alloc_ops_t *, /* args */ ...);

View File

@ -269,12 +269,25 @@ nvlist_nvflag(nvlist_t *nvl)
int
nvlist_alloc(nvlist_t **nvlp, uint_t nvflag, int kmflag)
{
nv_alloc_t *nva = nv_alloc_nosleep;
#if defined(_KERNEL) && !defined(_BOOT)
return (nvlist_xalloc(nvlp, nvflag,
(kmflag == KM_SLEEP ? nv_alloc_sleep : nv_alloc_nosleep)));
#else
return (nvlist_xalloc(nvlp, nvflag, nv_alloc_nosleep));
switch (kmflag) {
case KM_SLEEP:
nva = nv_alloc_sleep;
break;
case KM_PUSHPAGE:
nva = nv_alloc_pushpage;
break;
case KM_NOSLEEP:
nva = nv_alloc_nosleep;
break;
default:
return (EINVAL);
}
#endif
return (nvlist_xalloc(nvlp, nvflag, nva));
}
int

View File

@ -33,6 +33,12 @@ nv_alloc_sleep_spl(nv_alloc_t *nva, size_t size)
return (kmem_alloc(size, KM_SLEEP | KM_NODEBUG));
}
static void *
nv_alloc_pushpage_spl(nv_alloc_t *nva, size_t size)
{
return (kmem_alloc(size, KM_PUSHPAGE | KM_NODEBUG));
}
static void *
nv_alloc_nosleep_spl(nv_alloc_t *nva, size_t size)
{
@ -53,6 +59,14 @@ const nv_alloc_ops_t spl_sleep_ops_def = {
NULL /* nv_ao_reset() */
};
const nv_alloc_ops_t spl_pushpage_ops_def = {
NULL, /* nv_ao_init() */
NULL, /* nv_ao_fini() */
nv_alloc_pushpage_spl, /* nv_ao_alloc() */
nv_free_spl, /* nv_ao_free() */
NULL /* nv_ao_reset() */
};
const nv_alloc_ops_t spl_nosleep_ops_def = {
NULL, /* nv_ao_init() */
NULL, /* nv_ao_fini() */
@ -66,10 +80,16 @@ nv_alloc_t nv_alloc_sleep_def = {
NULL
};
nv_alloc_t nv_alloc_pushpage_def = {
&spl_pushpage_ops_def,
NULL
};
nv_alloc_t nv_alloc_nosleep_def = {
&spl_nosleep_ops_def,
NULL
};
nv_alloc_t *nv_alloc_sleep = &nv_alloc_sleep_def;
nv_alloc_t *nv_alloc_pushpage = &nv_alloc_pushpage_def;
nv_alloc_t *nv_alloc_nosleep = &nv_alloc_nosleep_def;