forked from illumos/illumos-gate
/
vm_swap.c
1800 lines (1618 loc) · 46.9 KB
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vm_swap.c
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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 1987, 2010, Oracle and/or its affiliates. All rights reserved.
*/
/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
/*
* University Copyright- Copyright (c) 1982, 1986, 1988
* The Regents of the University of California
* All Rights Reserved
*
* University Acknowledgment- Portions of this document are derived from
* software developed by the University of California, Berkeley, and its
* contributors.
*/
/*
* Each physical swap area has an associated bitmap representing
* its physical storage. The bitmap records which swap slots are
* currently allocated or freed. Allocation is done by searching
* through the bitmap for the first free slot. Thus, there's
* no linear relation between offset within the swap device and the
* address (within its segment(s)) of the page that the slot backs;
* instead, it's an arbitrary one-to-one mapping.
*
* Associated with each swap area is a swapinfo structure. These
* structures are linked into a linear list that determines the
* ordering of swap areas in the logical swap device. Each contains a
* pointer to the corresponding bitmap, the area's size, and its
* associated vnode.
*/
#include <sys/types.h>
#include <sys/inttypes.h>
#include <sys/param.h>
#include <sys/t_lock.h>
#include <sys/sysmacros.h>
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/kmem.h>
#include <sys/vfs.h>
#include <sys/vnode.h>
#include <sys/pathname.h>
#include <sys/cmn_err.h>
#include <sys/vtrace.h>
#include <sys/swap.h>
#include <sys/dumphdr.h>
#include <sys/debug.h>
#include <sys/fs/snode.h>
#include <sys/fs/swapnode.h>
#include <sys/policy.h>
#include <sys/zone.h>
#include <vm/as.h>
#include <vm/seg.h>
#include <vm/page.h>
#include <vm/seg_vn.h>
#include <vm/hat.h>
#include <vm/anon.h>
#include <vm/seg_map.h>
/*
* To balance the load among multiple swap areas, we don't allow
* more than swap_maxcontig allocations to be satisfied from a
* single swap area before moving on to the next swap area. This
* effectively "interleaves" allocations among the many swap areas.
*/
int swap_maxcontig; /* set by anon_init() to 1 Mb */
#define MINIROOTSIZE 12000 /* ~6 Meg XXX */
/*
* XXX - this lock is a kludge. It serializes some aspects of swapadd() and
* swapdel() (namely VOP_OPEN, VOP_CLOSE, VN_RELE). It protects against
* somebody swapadd'ing and getting swap slots from a vnode, while someone
* else is in the process of closing or rele'ing it.
*/
static kmutex_t swap_lock;
kmutex_t swapinfo_lock;
/*
* protected by the swapinfo_lock
*/
struct swapinfo *swapinfo;
static struct swapinfo *silast;
static int nswapfiles;
static u_offset_t swap_getoff(struct swapinfo *);
static int swapadd(struct vnode *, ulong_t, ulong_t, char *);
static int swapdel(struct vnode *, ulong_t);
static int swapslot_free(struct vnode *, u_offset_t, struct swapinfo *);
/*
* swap device bitmap allocation macros
*/
#define MAPSHIFT 5
#define NBBW (NBPW * NBBY) /* number of bits per word */
#define TESTBIT(map, i) (((map)[(i) >> MAPSHIFT] & (1 << (i) % NBBW)))
#define SETBIT(map, i) (((map)[(i) >> MAPSHIFT] |= (1 << (i) % NBBW)))
#define CLEARBIT(map, i) (((map)[(i) >> MAPSHIFT] &= ~(1 << (i) % NBBW)))
int swap_debug = 0; /* set for debug printf's */
int swap_verify = 0; /* set to verify slots when freeing and allocating */
uint_t swapalloc_maxcontig;
/*
* Allocate a range of up to *lenp contiguous slots (page) from a physical
* swap device. Flags are one of:
* SA_NOT Must have a slot from a physical swap device other than the
* the one containing input (*vpp, *offp).
* Less slots than requested may be returned. *lenp allocated slots are
* returned starting at *offp on *vpp.
* Returns 1 for a successful allocation, 0 for couldn't allocate any slots.
*/
int
swap_phys_alloc(
struct vnode **vpp,
u_offset_t *offp,
size_t *lenp,
uint_t flags)
{
struct swapinfo *sip;
offset_t soff, noff;
size_t len;
mutex_enter(&swapinfo_lock);
sip = silast;
/* Find a desirable physical device and allocate from it. */
do {
if (sip == NULL)
break;
if (!(sip->si_flags & ST_INDEL) &&
(spgcnt_t)sip->si_nfpgs > 0) {
/* Caller wants other than specified swap device */
if (flags & SA_NOT) {
if (*vpp != sip->si_vp ||
*offp < sip->si_soff ||
*offp >= sip->si_eoff)
goto found;
/* Caller is loose, will take anything */
} else
goto found;
} else if (sip->si_nfpgs == 0)
sip->si_allocs = 0;
if ((sip = sip->si_next) == NULL)
sip = swapinfo;
} while (sip != silast);
mutex_exit(&swapinfo_lock);
return (0);
found:
soff = swap_getoff(sip);
sip->si_nfpgs--;
if (soff == -1)
panic("swap_alloc: swap_getoff failed!");
for (len = PAGESIZE; len < *lenp; len += PAGESIZE) {
if (sip->si_nfpgs == 0)
break;
if (swapalloc_maxcontig && len >= swapalloc_maxcontig)
break;
noff = swap_getoff(sip);
if (noff == -1) {
break;
} else if (noff != soff + len) {
CLEARBIT(sip->si_swapslots, btop(noff - sip->si_soff));
break;
}
sip->si_nfpgs--;
}
*vpp = sip->si_vp;
*offp = soff;
*lenp = len;
ASSERT((spgcnt_t)sip->si_nfpgs >= 0);
sip->si_allocs += btop(len);
if (sip->si_allocs >= swap_maxcontig) {
sip->si_allocs = 0;
if ((silast = sip->si_next) == NULL)
silast = swapinfo;
}
TRACE_2(TR_FAC_VM, TR_SWAP_ALLOC,
"swap_alloc:sip %p offset %lx", sip, soff);
mutex_exit(&swapinfo_lock);
return (1);
}
int swap_backsearch = 0;
/*
* Get a free offset on swap device sip.
* Return >=0 offset if succeeded, -1 for failure.
*/
static u_offset_t
swap_getoff(struct swapinfo *sip)
{
uint_t *sp, *ep;
size_t aoff, boff, poff, slotnumber;
ASSERT(MUTEX_HELD(&swapinfo_lock));
sip->si_alloccnt++;
for (sp = &sip->si_swapslots[sip->si_hint >> MAPSHIFT],
ep = &sip->si_swapslots[sip->si_mapsize / NBPW]; sp < ep; sp++) {
if (*sp != (uint_t)0xffffffff)
goto foundentry;
else
sip->si_checkcnt++;
}
SWAP_PRINT(SW_ALLOC,
"swap_getoff: couldn't find slot from hint %ld to end\n",
sip->si_hint, 0, 0, 0, 0);
/*
* Go backwards? Check for faster method XXX
*/
if (swap_backsearch) {
for (sp = &sip->si_swapslots[sip->si_hint >> MAPSHIFT],
ep = sip->si_swapslots; sp > ep; sp--) {
if (*sp != (uint_t)0xffffffff)
goto foundentry;
else
sip->si_checkcnt++;
}
} else {
for (sp = sip->si_swapslots,
ep = &sip->si_swapslots[sip->si_hint >> MAPSHIFT];
sp < ep; sp++) {
if (*sp != (uint_t)0xffffffff)
goto foundentry;
else
sip->si_checkcnt++;
}
}
if (*sp == 0xffffffff) {
cmn_err(CE_WARN, "No free swap slots!");
return ((u_offset_t)-1);
}
foundentry:
/*
* aoff is the page number offset (in bytes) of the si_swapslots
* array element containing a free page
*
* boff is the page number offset of the free page
* (i.e. cleared bit) in si_swapslots[aoff].
*/
aoff = ((char *)sp - (char *)sip->si_swapslots) * NBBY;
for (boff = (sip->si_hint % NBBW); boff < NBBW; boff++) {
if (!TESTBIT(sip->si_swapslots, aoff + boff))
goto foundslot;
else
sip->si_checkcnt++;
}
for (boff = 0; boff < (sip->si_hint % NBBW); boff++) {
if (!TESTBIT(sip->si_swapslots, aoff + boff))
goto foundslot;
else
sip->si_checkcnt++;
}
panic("swap_getoff: didn't find slot in word hint %ld", sip->si_hint);
foundslot:
/*
* Return the offset of the free page in swap device.
* Convert page number of byte offset and add starting
* offset of swap device.
*/
slotnumber = aoff + boff;
SWAP_PRINT(SW_ALLOC, "swap_getoff: allocating slot %ld\n",
slotnumber, 0, 0, 0, 0);
poff = ptob(slotnumber);
if (poff + sip->si_soff >= sip->si_eoff)
printf("ptob(aoff(%ld) + boff(%ld))(%ld) >= eoff(%ld)\n",
aoff, boff, ptob(slotnumber), (long)sip->si_eoff);
ASSERT(poff < sip->si_eoff);
/*
* We could verify here that the slot isn't already allocated
* by looking through all the anon slots.
*/
SETBIT(sip->si_swapslots, slotnumber);
sip->si_hint = slotnumber + 1; /* hint = next slot */
return (poff + sip->si_soff);
}
/*
* Free a swap page.
*/
void
swap_phys_free(struct vnode *vp, u_offset_t off, size_t len)
{
struct swapinfo *sip;
ssize_t pagenumber, npage;
mutex_enter(&swapinfo_lock);
sip = swapinfo;
do {
if (sip->si_vp == vp &&
sip->si_soff <= off && off < sip->si_eoff) {
for (pagenumber = btop(off - sip->si_soff),
npage = btop(len) + pagenumber;
pagenumber < npage; pagenumber++) {
SWAP_PRINT(SW_ALLOC,
"swap_phys_free: freeing slot %ld on "
"sip %p\n",
pagenumber, sip, 0, 0, 0);
if (!TESTBIT(sip->si_swapslots, pagenumber)) {
panic(
"swap_phys_free: freeing free slot "
"%p,%lx\n", (void *)vp,
ptob(pagenumber) + sip->si_soff);
}
CLEARBIT(sip->si_swapslots, pagenumber);
sip->si_nfpgs++;
}
ASSERT(sip->si_nfpgs <= sip->si_npgs);
mutex_exit(&swapinfo_lock);
return;
}
} while ((sip = sip->si_next) != NULL);
panic("swap_phys_free");
/*NOTREACHED*/
}
/*
* Return the anon struct corresponding for the given
* <vnode, off> if it is part of the virtual swap device.
* Return the anon struct if found, otherwise NULL.
*/
struct anon *
swap_anon(struct vnode *vp, u_offset_t off)
{
struct anon *ap;
ASSERT(MUTEX_HELD(AH_MUTEX(vp, off)));
for (ap = anon_hash[ANON_HASH(vp, off)]; ap != NULL; ap = ap->an_hash) {
if (ap->an_vp == vp && ap->an_off == off)
return (ap);
}
return (NULL);
}
/*
* Determine if the vp offset range overlap a swap device.
*/
int
swap_in_range(struct vnode *vp, u_offset_t offset, size_t len)
{
struct swapinfo *sip;
u_offset_t eoff;
eoff = offset + len;
ASSERT(eoff > offset);
mutex_enter(&swapinfo_lock);
sip = swapinfo;
if (vp && sip) {
do {
if (vp != sip->si_vp || eoff <= sip->si_soff ||
offset >= sip->si_eoff)
continue;
mutex_exit(&swapinfo_lock);
return (1);
} while ((sip = sip->si_next) != NULL);
}
mutex_exit(&swapinfo_lock);
return (0);
}
/*
* See if name is one of our swap files
* even though lookupname failed.
* This can be used by swapdel to delete
* swap resources on remote machines
* where the link has gone down.
*/
static struct vnode *
swapdel_byname(
char *name, /* pathname to delete */
ulong_t lowblk) /* Low block number of area to delete */
{
struct swapinfo **sipp, *osip;
u_offset_t soff;
/*
* Find the swap file entry for the file to
* be deleted. Skip any entries that are in
* transition.
*/
soff = ptob(btopr(lowblk << SCTRSHFT)); /* must be page aligned */
mutex_enter(&swapinfo_lock);
for (sipp = &swapinfo; (osip = *sipp) != NULL; sipp = &osip->si_next) {
if ((strcmp(osip->si_pname, name) == 0) &&
(osip->si_soff == soff) && (osip->si_flags == 0)) {
struct vnode *vp = osip->si_vp;
VN_HOLD(vp);
mutex_exit(&swapinfo_lock);
return (vp);
}
}
mutex_exit(&swapinfo_lock);
return (NULL);
}
/*
* New system call to manipulate swap files.
*/
int
swapctl(int sc_cmd, void *sc_arg, int *rv)
{
struct swapinfo *sip, *csip, *tsip;
int error = 0;
struct swapent st, *ust;
struct swapres sr;
struct vnode *vp;
int cnt = 0;
int tmp_nswapfiles;
int nswap;
int length, nlen;
int gplen = 0, plen;
char *swapname;
char *pname;
char *tpname;
struct anoninfo ai;
spgcnt_t avail;
int global = INGLOBALZONE(curproc);
struct zone *zp = curproc->p_zone;
/*
* When running in a zone we want to hide the details of the swap
* devices: we report there only being one swap device named "swap"
* having a size equal to the sum of the sizes of all real swap devices
* on the system.
*/
switch (sc_cmd) {
case SC_GETNSWP:
if (global)
*rv = nswapfiles;
else
*rv = 1;
return (0);
case SC_AINFO:
/*
* Return anoninfo information with these changes:
* ani_max = maximum amount of swap space
* (including potentially available physical memory)
* ani_free = amount of unallocated anonymous memory
* (some of which might be reserved and including
* potentially available physical memory)
* ani_resv = amount of claimed (reserved) anonymous memory
*/
avail = MAX((spgcnt_t)(availrmem - swapfs_minfree), 0);
ai.ani_max = (k_anoninfo.ani_max +
k_anoninfo.ani_mem_resv) + avail;
/* Update ani_free */
set_anoninfo();
ai.ani_free = k_anoninfo.ani_free + avail;
ai.ani_resv = k_anoninfo.ani_phys_resv +
k_anoninfo.ani_mem_resv;
if (!global && zp->zone_max_swap_ctl != UINT64_MAX) {
/*
* We're in a non-global zone with a swap cap. We
* always report the system-wide values for the global
* zone, even though it too can have a swap cap.
*/
/*
* For a swap-capped zone, the numbers are contrived
* since we don't have a correct value of 'reserved'
* for the zone.
*
* The ani_max value is always the zone's swap cap.
*
* The ani_free value is always the difference between
* the cap and the amount of swap in use by the zone.
*
* The ani_resv value is typically set to be the amount
* of swap in use by the zone, but can be adjusted
* upwards to indicate how much swap is currently
* unavailable to that zone due to usage by entities
* outside the zone.
*
* This works as follows.
*
* In the 'swap -s' output, the data is displayed
* as follows:
* allocated = ani_max - ani_free
* reserved = ani_resv - allocated
* available = ani_max - ani_resv
*
* Taking a contrived example, if the swap cap is 100
* and the amount of swap used by the zone is 75, this
* gives:
* allocated = ani_max - ani_free = 100 - 25 = 75
* reserved = ani_resv - allocated = 75 - 75 = 0
* available = ani_max - ani_resv = 100 - 75 = 25
*
* In this typical case, you can see that the 'swap -s'
* 'reserved' will always be 0 inside a swap capped
* zone.
*
* However, if the system as a whole has less free
* swap than the zone limits allow, then we adjust
* the ani_resv value up so that it is the difference
* between the zone cap and the amount of free system
* swap. Taking the above example, but when the
* system as a whole only has 20 of swap available, we
* get an ani_resv of 100 - 20 = 80. This gives:
* allocated = ani_max - ani_free = 100 - 25 = 75
* reserved = ani_resv - allocated = 80 - 75 = 5
* available = ani_max - ani_resv = 100 - 80 = 20
*
* In this case, you can see how the ani_resv value is
* tweaked up to make the 'swap -s' numbers work inside
* the zone.
*/
rctl_qty_t cap, used;
pgcnt_t pgcap, sys_avail;
mutex_enter(&zp->zone_mem_lock);
cap = zp->zone_max_swap_ctl;
used = zp->zone_max_swap;
mutex_exit(&zp->zone_mem_lock);
pgcap = MIN(btop(cap), ai.ani_max);
ai.ani_free = pgcap - btop(used);
/* Get the system-wide swap currently available. */
sys_avail = ai.ani_max - ai.ani_resv;
if (sys_avail < ai.ani_free)
ai.ani_resv = pgcap - sys_avail;
else
ai.ani_resv = btop(used);
ai.ani_max = pgcap;
}
if (copyout(&ai, sc_arg, sizeof (struct anoninfo)) != 0)
return (EFAULT);
return (0);
case SC_LIST:
if (copyin(sc_arg, &length, sizeof (int)) != 0)
return (EFAULT);
if (!global) {
struct swapent st;
char *swappath = "swap";
if (length < 1)
return (ENOMEM);
ust = (swapent_t *)((swaptbl_t *)sc_arg)->swt_ent;
if (copyin(ust, &st, sizeof (swapent_t)) != 0)
return (EFAULT);
st.ste_start = PAGESIZE >> SCTRSHFT;
st.ste_length = (off_t)0;
st.ste_pages = 0;
st.ste_free = 0;
st.ste_flags = 0;
mutex_enter(&swapinfo_lock);
for (sip = swapinfo, nswap = 0;
sip != NULL && nswap < nswapfiles;
sip = sip->si_next, nswap++) {
st.ste_length +=
(sip->si_eoff - sip->si_soff) >> SCTRSHFT;
st.ste_pages += sip->si_npgs;
st.ste_free += sip->si_nfpgs;
}
mutex_exit(&swapinfo_lock);
if (zp->zone_max_swap_ctl != UINT64_MAX) {
rctl_qty_t cap, used;
mutex_enter(&zp->zone_mem_lock);
cap = zp->zone_max_swap_ctl;
used = zp->zone_max_swap;
mutex_exit(&zp->zone_mem_lock);
st.ste_length = MIN(cap, st.ste_length);
st.ste_pages = MIN(btop(cap), st.ste_pages);
st.ste_free = MIN(st.ste_pages - btop(used),
st.ste_free);
}
if (copyout(&st, ust, sizeof (swapent_t)) != 0 ||
copyout(swappath, st.ste_path,
strlen(swappath) + 1) != 0) {
return (EFAULT);
}
*rv = 1;
return (0);
}
beginning:
tmp_nswapfiles = nswapfiles;
/* Return an error if not enough space for the whole table. */
if (length < tmp_nswapfiles)
return (ENOMEM);
/*
* Get memory to hold the swap entries and their names. We'll
* copy the real entries into these and then copy these out.
* Allocating the pathname memory is only a guess so we may
* find that we need more and have to do it again.
* All this is because we have to hold the anon lock while
* traversing the swapinfo list, and we can't be doing copyouts
* and/or kmem_alloc()s during this.
*/
csip = kmem_zalloc(tmp_nswapfiles * sizeof (struct swapinfo),
KM_SLEEP);
retry:
nlen = tmp_nswapfiles * (gplen += 100);
pname = kmem_zalloc(nlen, KM_SLEEP);
mutex_enter(&swapinfo_lock);
if (tmp_nswapfiles != nswapfiles) {
mutex_exit(&swapinfo_lock);
kmem_free(pname, nlen);
kmem_free(csip,
tmp_nswapfiles * sizeof (struct swapinfo));
gplen = 0;
goto beginning;
}
for (sip = swapinfo, tsip = csip, tpname = pname, nswap = 0;
sip && nswap < tmp_nswapfiles;
sip = sip->si_next, tsip++, tpname += plen, nswap++) {
plen = sip->si_pnamelen;
if (tpname + plen - pname > nlen) {
mutex_exit(&swapinfo_lock);
kmem_free(pname, nlen);
goto retry;
}
*tsip = *sip;
tsip->si_pname = tpname;
(void) strcpy(tsip->si_pname, sip->si_pname);
}
mutex_exit(&swapinfo_lock);
if (sip) {
error = ENOMEM;
goto lout;
}
ust = (swapent_t *)((swaptbl_t *)sc_arg)->swt_ent;
for (tsip = csip, cnt = 0; cnt < nswap; tsip++, ust++, cnt++) {
if (copyin(ust, &st, sizeof (swapent_t)) != 0) {
error = EFAULT;
goto lout;
}
st.ste_flags = tsip->si_flags;
st.ste_length =
(tsip->si_eoff - tsip->si_soff) >> SCTRSHFT;
st.ste_start = tsip->si_soff >> SCTRSHFT;
st.ste_pages = tsip->si_npgs;
st.ste_free = tsip->si_nfpgs;
if (copyout(&st, ust, sizeof (swapent_t)) != 0) {
error = EFAULT;
goto lout;
}
if (!tsip->si_pnamelen)
continue;
if (copyout(tsip->si_pname, st.ste_path,
tsip->si_pnamelen) != 0) {
error = EFAULT;
goto lout;
}
}
*rv = nswap;
lout:
kmem_free(csip, tmp_nswapfiles * sizeof (struct swapinfo));
kmem_free(pname, nlen);
return (error);
case SC_ADD:
case SC_REMOVE:
break;
default:
return (EINVAL);
}
if ((error = secpolicy_swapctl(CRED())) != 0)
return (error);
if (copyin(sc_arg, &sr, sizeof (swapres_t)))
return (EFAULT);
/* Allocate the space to read in pathname */
if ((swapname = kmem_alloc(MAXPATHLEN, KM_NOSLEEP)) == NULL)
return (ENOMEM);
error = copyinstr(sr.sr_name, swapname, MAXPATHLEN, 0);
if (error)
goto out;
error = lookupname(swapname, UIO_SYSSPACE, FOLLOW, NULLVPP, &vp);
if (error) {
if (sc_cmd == SC_ADD)
goto out;
/* see if we match by name */
vp = swapdel_byname(swapname, (size_t)sr.sr_start);
if (vp == NULL)
goto out;
}
if (vp->v_flag & (VNOMAP | VNOSWAP)) {
VN_RELE(vp);
error = ENOSYS;
goto out;
}
switch (vp->v_type) {
case VBLK:
break;
case VREG:
if (vp->v_vfsp && vn_is_readonly(vp))
error = EROFS;
else
error = VOP_ACCESS(vp, VREAD|VWRITE, 0, CRED(), NULL);
break;
case VDIR:
error = EISDIR;
break;
default:
error = ENOSYS;
break;
}
if (error == 0) {
if (sc_cmd == SC_REMOVE)
error = swapdel(vp, sr.sr_start);
else
error = swapadd(vp, sr.sr_start,
sr.sr_length, swapname);
}
VN_RELE(vp);
out:
kmem_free(swapname, MAXPATHLEN);
return (error);
}
#if defined(_LP64) && defined(_SYSCALL32)
int
swapctl32(int sc_cmd, void *sc_arg, int *rv)
{
struct swapinfo *sip, *csip, *tsip;
int error = 0;
struct swapent32 st, *ust;
struct swapres32 sr;
struct vnode *vp;
int cnt = 0;
int tmp_nswapfiles;
int nswap;
int length, nlen;
int gplen = 0, plen;
char *swapname;
char *pname;
char *tpname;
struct anoninfo32 ai;
size_t s;
spgcnt_t avail;
int global = INGLOBALZONE(curproc);
struct zone *zp = curproc->p_zone;
/*
* When running in a zone we want to hide the details of the swap
* devices: we report there only being one swap device named "swap"
* having a size equal to the sum of the sizes of all real swap devices
* on the system.
*/
switch (sc_cmd) {
case SC_GETNSWP:
if (global)
*rv = nswapfiles;
else
*rv = 1;
return (0);
case SC_AINFO:
/*
* Return anoninfo information with these changes:
* ani_max = maximum amount of swap space
* (including potentially available physical memory)
* ani_free = amount of unallocated anonymous memory
* (some of which might be reserved and including
* potentially available physical memory)
* ani_resv = amount of claimed (reserved) anonymous memory
*/
avail = MAX((spgcnt_t)(availrmem - swapfs_minfree), 0);
s = (k_anoninfo.ani_max + k_anoninfo.ani_mem_resv) + avail;
if (s > UINT32_MAX)
return (EOVERFLOW);
ai.ani_max = s;
/* Update ani_free */
set_anoninfo();
s = k_anoninfo.ani_free + avail;
if (s > UINT32_MAX)
return (EOVERFLOW);
ai.ani_free = s;
s = k_anoninfo.ani_phys_resv + k_anoninfo.ani_mem_resv;
if (s > UINT32_MAX)
return (EOVERFLOW);
ai.ani_resv = s;
if (!global && zp->zone_max_swap_ctl != UINT64_MAX) {
/*
* We're in a non-global zone with a swap cap. We
* always report the system-wide values for the global
* zone, even though it too can have a swap cap.
* See the comment for the SC_AINFO case in swapctl()
* which explains the following logic.
*/
rctl_qty_t cap, used;
pgcnt_t pgcap, sys_avail;
mutex_enter(&zp->zone_mem_lock);
cap = zp->zone_max_swap_ctl;
used = zp->zone_max_swap;
mutex_exit(&zp->zone_mem_lock);
pgcap = MIN(btop(cap), ai.ani_max);
ai.ani_free = pgcap - btop(used);
/* Get the system-wide swap currently available. */
sys_avail = ai.ani_max - ai.ani_resv;
if (sys_avail < ai.ani_free)
ai.ani_resv = pgcap - sys_avail;
else
ai.ani_resv = btop(used);
ai.ani_max = pgcap;
}
if (copyout(&ai, sc_arg, sizeof (ai)) != 0)
return (EFAULT);
return (0);
case SC_LIST:
if (copyin(sc_arg, &length, sizeof (int32_t)) != 0)
return (EFAULT);
if (!global) {
struct swapent32 st;
char *swappath = "swap";
if (length < 1)
return (ENOMEM);
ust = (swapent32_t *)((swaptbl32_t *)sc_arg)->swt_ent;
if (copyin(ust, &st, sizeof (swapent32_t)) != 0)
return (EFAULT);
st.ste_start = PAGESIZE >> SCTRSHFT;
st.ste_length = (off_t)0;
st.ste_pages = 0;
st.ste_free = 0;
st.ste_flags = 0;
mutex_enter(&swapinfo_lock);
for (sip = swapinfo, nswap = 0;
sip != NULL && nswap < nswapfiles;
sip = sip->si_next, nswap++) {
st.ste_length +=
(sip->si_eoff - sip->si_soff) >> SCTRSHFT;
st.ste_pages += sip->si_npgs;
st.ste_free += sip->si_nfpgs;
}
mutex_exit(&swapinfo_lock);
if (zp->zone_max_swap_ctl != UINT64_MAX) {
rctl_qty_t cap, used;
mutex_enter(&zp->zone_mem_lock);
cap = zp->zone_max_swap_ctl;
used = zp->zone_max_swap;
mutex_exit(&zp->zone_mem_lock);
st.ste_length = MIN(cap, st.ste_length);
st.ste_pages = MIN(btop(cap), st.ste_pages);
st.ste_free = MIN(st.ste_pages - btop(used),
st.ste_free);
}
if (copyout(&st, ust, sizeof (swapent32_t)) != 0 ||
copyout(swappath, (caddr_t)(uintptr_t)st.ste_path,
strlen(swappath) + 1) != 0) {
return (EFAULT);
}
*rv = 1;
return (0);
}
beginning:
tmp_nswapfiles = nswapfiles;
/* Return an error if not enough space for the whole table. */
if (length < tmp_nswapfiles)
return (ENOMEM);
/*
* Get memory to hold the swap entries and their names. We'll
* copy the real entries into these and then copy these out.
* Allocating the pathname memory is only a guess so we may
* find that we need more and have to do it again.
* All this is because we have to hold the anon lock while
* traversing the swapinfo list, and we can't be doing copyouts
* and/or kmem_alloc()s during this.
*/
csip = kmem_zalloc(tmp_nswapfiles * sizeof (*csip), KM_SLEEP);
retry:
nlen = tmp_nswapfiles * (gplen += 100);
pname = kmem_zalloc(nlen, KM_SLEEP);
mutex_enter(&swapinfo_lock);
if (tmp_nswapfiles != nswapfiles) {
mutex_exit(&swapinfo_lock);
kmem_free(pname, nlen);
kmem_free(csip, tmp_nswapfiles * sizeof (*csip));
gplen = 0;
goto beginning;
}
for (sip = swapinfo, tsip = csip, tpname = pname, nswap = 0;
(sip != NULL) && (nswap < tmp_nswapfiles);
sip = sip->si_next, tsip++, tpname += plen, nswap++) {
plen = sip->si_pnamelen;
if (tpname + plen - pname > nlen) {
mutex_exit(&swapinfo_lock);
kmem_free(pname, nlen);
goto retry;
}
*tsip = *sip;
tsip->si_pname = tpname;
(void) strcpy(tsip->si_pname, sip->si_pname);
}
mutex_exit(&swapinfo_lock);
if (sip != NULL) {
error = ENOMEM;
goto lout;
}
ust = (swapent32_t *)((swaptbl32_t *)sc_arg)->swt_ent;
for (tsip = csip, cnt = 0; cnt < nswap; tsip++, ust++, cnt++) {
if (copyin(ust, &st, sizeof (*ust)) != 0) {
error = EFAULT;
goto lout;
}
st.ste_flags = tsip->si_flags;
st.ste_length =
(tsip->si_eoff - tsip->si_soff) >> SCTRSHFT;
st.ste_start = tsip->si_soff >> SCTRSHFT;
st.ste_pages = tsip->si_npgs;
st.ste_free = tsip->si_nfpgs;
if (copyout(&st, ust, sizeof (st)) != 0) {
error = EFAULT;
goto lout;
}
if (!tsip->si_pnamelen)
continue;
if (copyout(tsip->si_pname,
(caddr_t)(uintptr_t)st.ste_path,
tsip->si_pnamelen) != 0) {
error = EFAULT;
goto lout;
}
}
*rv = nswap;
lout:
kmem_free(csip, tmp_nswapfiles * sizeof (*csip));
kmem_free(pname, nlen);
return (error);
case SC_ADD: