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Protect the swapdevice tailq with a mutex.

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Store the udev_t we will report to userland in the swdevt.
This commit is contained in:
Poul-Henning Kamp 2003-08-30 16:10:28 +00:00
parent 7ea02dcd89
commit 20da9c2eaf
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=119590
1 changed files with 50 additions and 23 deletions
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73
sys/vm/swap_pager.c
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@ -151,6 +151,7 @@ struct swdevt {
int sw_flags;
int sw_nblks;
int sw_used;
udev_t sw_udev;
void *sw_id;
swblk_t sw_first;
swblk_t sw_end;
@ -169,6 +170,7 @@ struct swblock {
daddr_t swb_pages[SWAP_META_PAGES];
};
static struct mtx sw_dev_mtx;
static TAILQ_HEAD(, swdevt) swtailq = TAILQ_HEAD_INITIALIZER(swtailq);
static struct swdevt *swdevhd; /* Allocate from here next */
static int nswapdev; /* Number of swap devices */
@ -351,6 +353,7 @@ swap_pager_init(void)
TAILQ_INIT(&swap_pager_object_list[i]);
TAILQ_INIT(&swap_pager_un_object_list);
mtx_init(&sw_alloc_mtx, "swap_pager list", NULL, MTX_DEF);
mtx_init(&sw_dev_mtx, "swapdev", NULL, MTX_DEF);
/*
* Device Stripe, in PAGE_SIZE'd blocks
@ -573,6 +576,7 @@ swp_pager_getswapspace(int npages)
GIANT_REQUIRED;
blk = SWAPBLK_NONE;
mtx_lock(&sw_dev_mtx);
sp = swdevhd;
for (i = 0; i < nswapdev; i++) {
if (sp == NULL)
@ -585,13 +589,15 @@ swp_pager_getswapspace(int npages)
sp->sw_used += npages;
swp_sizecheck();
swdevhd = TAILQ_NEXT(sp, sw_list);
mtx_unlock(&sw_dev_mtx);
return(blk);
}
}
sp = TAILQ_NEXT(sp, sw_list);
}
mtx_unlock(&sw_dev_mtx);
if (swap_pager_full != 2) {
printf("swap_pager_getswapspace: failed\n");
printf("swap_pager_getswapspace(%d): failed\n", npages);
swap_pager_full = 2;
swap_pager_almost_full = 1;
}
@ -604,15 +610,14 @@ swp_pager_find_dev(daddr_t blk)
{
struct swdevt *sp;
mtx_lock(&sw_dev_mtx);
TAILQ_FOREACH(sp, &swtailq, sw_list) {
if (blk >= sp->sw_first && blk < sp->sw_end)
if (blk >= sp->sw_first && blk < sp->sw_end) {
mtx_unlock(&sw_dev_mtx);
return (sp);
}
}
printf("Failed to find swapdev blk %ju\n", (uintmax_t)blk);
TAILQ_FOREACH(sp, &swtailq, sw_list)
printf("has %ju...%ju\n",
(uintmax_t)sp->sw_first, (uintmax_t)sp->sw_end);
return (NULL);
panic("Swapdev not found");
}
static void
@ -620,13 +625,15 @@ swp_pager_strategy(struct buf *bp)
{
struct swdevt *sp;
mtx_lock(&sw_dev_mtx);
TAILQ_FOREACH(sp, &swtailq, sw_list) {
if (bp->b_blkno >= sp->sw_first && bp->b_blkno < sp->sw_end) {
mtx_unlock(&sw_dev_mtx);
sp->sw_strategy(bp, sp);
return;
}
}
KASSERT(0 == 1, ("Swapdev not found"));
panic("Swapdev not found");
}
@ -2094,9 +2101,9 @@ swapon(struct thread *td, struct swapon_args *uap)
NDFREE(&nd, NDF_ONLY_PNBUF);
vp = nd.ni_vp;
if (vn_isdisk(vp, &error))
if (vn_isdisk(vp, &error)) {
error = swapondev(td, vp);
else if (vp->v_type == VREG &&
} else if (vp->v_type == VREG &&
(vp->v_mount->mnt_vfc->vfc_flags & VFCF_NETWORK) != 0 &&
(error = VOP_GETATTR(vp, &attr, td->td_ucred, td)) == 0) {
/*
@ -2117,13 +2124,14 @@ swapon(struct thread *td, struct swapon_args *uap)
}
static void
swaponsomething(struct vnode *vp, u_long nblks, sw_strategy_t *strategy)
swaponsomething(void *vp, u_long nblks, sw_strategy_t *strategy, udev_t udev)
{
struct swdevt *sp;
swblk_t dvbase;
u_long mblocks;
dvbase = 0;
mtx_lock(&sw_dev_mtx);
TAILQ_FOREACH(sp, &swtailq, sw_list) {
if (sp->sw_end >= dvbase) {
/*
@ -2134,6 +2142,7 @@ swaponsomething(struct vnode *vp, u_long nblks, sw_strategy_t *strategy)
dvbase = sp->sw_end + 1;
}
}
mtx_unlock(&sw_dev_mtx);
/*
* If we go beyond this, we get overflows in the radix
@ -2156,6 +2165,7 @@ swaponsomething(struct vnode *vp, u_long nblks, sw_strategy_t *strategy)
sp = malloc(sizeof *sp, M_VMPGDATA, M_WAITOK | M_ZERO);
sp->sw_id = vp;
sp->sw_udev = udev;
sp->sw_flags = 0;
sp->sw_nblks = nblks;
sp->sw_used = 0;
@ -2170,7 +2180,9 @@ swaponsomething(struct vnode *vp, u_long nblks, sw_strategy_t *strategy)
*/
blist_free(sp->sw_blist, 2, nblks - 2);
mtx_lock(&sw_dev_mtx);
TAILQ_INSERT_TAIL(&swtailq, sp, sw_list);
mtx_unlock(&sw_dev_mtx);
nswapdev++;
swap_pager_avail += nblks;
swap_pager_full = 0;
@ -2185,9 +2197,14 @@ swapondev(struct thread *td, struct vnode *vp)
off_t mediasize;
u_long nblks;
TAILQ_FOREACH(sp, &swtailq, sw_list)
if (sp->sw_id == vp)
mtx_lock(&sw_dev_mtx);
TAILQ_FOREACH(sp, &swtailq, sw_list) {
if (sp->sw_id == vp) {
mtx_unlock(&sw_dev_mtx);
return (EBUSY);
}
}
mtx_unlock(&sw_dev_mtx);
(void) vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
#ifdef MAC
@ -2213,7 +2230,7 @@ swapondev(struct thread *td, struct vnode *vp)
* XXX: it should be a power of two, no larger than the page size.
*/
swaponsomething(vp, nblks, swapdev_devstrategy);
swaponsomething(vp, nblks, swapdev_devstrategy, dev2udev(vp->v_rdev));
return (0);
}
@ -2226,9 +2243,14 @@ swaponvp(struct thread *td, struct vnode *vp, u_long nblks)
if (nblks == 0)
return (ENXIO);
TAILQ_FOREACH(sp, &swtailq, sw_list)
if (sp->sw_id == vp)
mtx_lock(&sw_dev_mtx);
TAILQ_FOREACH(sp, &swtailq, sw_list) {
if (sp->sw_id == vp) {
mtx_unlock(&sw_dev_mtx);
return (EBUSY);
}
}
mtx_unlock(&sw_dev_mtx);
(void) vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
#ifdef MAC
@ -2240,7 +2262,7 @@ swaponvp(struct thread *td, struct vnode *vp, u_long nblks)
if (error)
return (error);
swaponsomething(vp, nblks, swapdev_strategy);
swaponsomething(vp, nblks, swapdev_strategy, NOUDEV);
return (0);
}
@ -2285,13 +2307,16 @@ swapoff(struct thread *td, struct swapoff_args *uap)
NDFREE(&nd, NDF_ONLY_PNBUF);
vp = nd.ni_vp;
mtx_lock(&sw_dev_mtx);
TAILQ_FOREACH(sp, &swtailq, sw_list) {
if (sp->sw_id == vp)
goto found;
}
mtx_unlock(&sw_dev_mtx);
error = EINVAL;
goto done;
found:
mtx_unlock(&sw_dev_mtx);
#ifdef MAC
(void) vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
error = mac_check_system_swapoff(td->td_ucred, vp);
@ -2334,7 +2359,9 @@ swapoff(struct thread *td, struct swapoff_args *uap)
VOP_CLOSE(vp, FREAD | FWRITE, td->td_ucred, td);
vrele(vp);
sp->sw_id = NULL;
mtx_lock(&sw_dev_mtx);
TAILQ_REMOVE(&swtailq, sp, sw_list);
mtx_unlock(&sw_dev_mtx);
if (swdevhd == sp)
swdevhd = NULL;
nswapdev--;
@ -2356,10 +2383,12 @@ swap_pager_status(int *total, int *used)
*total = 0;
*used = 0;
mtx_lock(&sw_dev_mtx);
TAILQ_FOREACH(sp, &swtailq, sw_list) {
*total += sp->sw_nblks;
*used += sp->sw_used;
}
mtx_unlock(&sw_dev_mtx);
}
static int
@ -2369,20 +2398,17 @@ sysctl_vm_swap_info(SYSCTL_HANDLER_ARGS)
int error, n;
struct xswdev xs;
struct swdevt *sp;
struct vnode *vp;
if (arg2 != 1) /* name length */
return (EINVAL);
n = 0;
mtx_lock(&sw_dev_mtx);
TAILQ_FOREACH(sp, &swtailq, sw_list) {
if (n == *name) {
mtx_unlock(&sw_dev_mtx);
xs.xsw_version = XSWDEV_VERSION;
vp = sp->sw_id;
if (vp->v_rdev != NULL)
xs.xsw_dev = dev2udev(vp->v_rdev);
else
xs.xsw_dev = NOUDEV;
xs.xsw_dev = sp->sw_udev;
xs.xsw_flags = sp->sw_flags;
xs.xsw_nblks = sp->sw_nblks;
xs.xsw_used = sp->sw_used;
@ -2392,6 +2418,7 @@ sysctl_vm_swap_info(SYSCTL_HANDLER_ARGS)
}
n++;
}
mtx_unlock(&sw_dev_mtx);
return (ENOENT);
}