/* $OpenBSD: uvm_swap.c,v 1.164 2022/08/29 11:09:31 mpi Exp $ */ /* $NetBSD: uvm_swap.c,v 1.40 2000/11/17 11:39:39 mrg Exp $ */ /* * Copyright (c) 1995, 1996, 1997 Matthew R. Green * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * from: NetBSD: vm_swap.c,v 1.52 1997/12/02 13:47:37 pk Exp * from: Id: uvm_swap.c,v 1.1.2.42 1998/02/02 20:38:06 chuck Exp */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if defined(NFSCLIENT) #include #include #include #include #endif #include #ifdef UVM_SWAP_ENCRYPT #include #endif #include #include "vnd.h" /* * uvm_swap.c: manage configuration and i/o to swap space. */ /* * swap space is managed in the following way: * * each swap partition or file is described by a "swapdev" structure. * each "swapdev" structure contains a "swapent" structure which contains * information that is passed up to the user (via system calls). * * each swap partition is assigned a "priority" (int) which controls * swap partition usage. * * the system maintains a global data structure describing all swap * partitions/files. there is a sorted LIST of "swappri" structures * which describe "swapdev"'s at that priority. this LIST is headed * by the "swap_priority" global var. each "swappri" contains a * TAILQ of "swapdev" structures at that priority. * * locking: * - swap_syscall_lock (sleep lock): this lock serializes the swapctl * system call and prevents the swap priority list from changing * while we are in the middle of a system call (e.g. SWAP_STATS). * - uvm_swap_data_lock (mutex): this lock protects all swap data * structures including the priority list, the swapdev structures, * and the swapmap arena. * * each swap device has the following info: * - swap device in use (could be disabled, preventing future use) * - swap enabled (allows new allocations on swap) * - map info in /dev/drum * - vnode pointer * for swap files only: * - block size * - max byte count in buffer * - buffer * - credentials to use when doing i/o to file * * userland controls and configures swap with the swapctl(2) system call. * the sys_swapctl performs the following operations: * [1] SWAP_NSWAP: returns the number of swap devices currently configured * [2] SWAP_STATS: given a pointer to an array of swapent structures * (passed in via "arg") of a size passed in via "misc" ... we load * the current swap config into the array. * [3] SWAP_ON: given a pathname in arg (could be device or file) and a * priority in "misc", start swapping on it. * [4] SWAP_OFF: as SWAP_ON, but stops swapping to a device * [5] SWAP_CTL: changes the priority of a swap device (new priority in * "misc") */ /* * swapdev: describes a single swap partition/file * * note the following should be true: * swd_inuse <= swd_nblks [number of blocks in use is <= total blocks] * swd_nblks <= swd_mapsize [because mapsize includes disklabel] */ struct swapdev { struct swapent swd_se; #define swd_dev swd_se.se_dev /* device id */ #define swd_flags swd_se.se_flags /* flags:inuse/enable/fake */ #define swd_priority swd_se.se_priority /* our priority */ #define swd_inuse swd_se.se_inuse /* blocks used */ #define swd_nblks swd_se.se_nblks /* total blocks */ char *swd_path; /* saved pathname of device */ int swd_pathlen; /* length of pathname */ int swd_npages; /* #pages we can use */ int swd_npginuse; /* #pages in use */ int swd_npgbad; /* #pages bad */ int swd_drumoffset; /* page0 offset in drum */ int swd_drumsize; /* #pages in drum */ blist_t swd_blist; /* blist for this swapdev */ struct vnode *swd_vp; /* backing vnode */ TAILQ_ENTRY(swapdev) swd_next; /* priority tailq */ int swd_bsize; /* blocksize (bytes) */ int swd_maxactive; /* max active i/o reqs */ int swd_active; /* # of active i/o reqs */ struct bufq swd_bufq; struct ucred *swd_cred; /* cred for file access */ #ifdef UVM_SWAP_ENCRYPT #define SWD_KEY_SHIFT 7 /* One key per 0.5 MByte */ #define SWD_KEY(x,y) &((x)->swd_keys[((y) - (x)->swd_drumoffset) >> SWD_KEY_SHIFT]) #define SWD_KEY_SIZE(x) (((x) + (1 << SWD_KEY_SHIFT) - 1) >> SWD_KEY_SHIFT) #define SWD_DCRYPT_SHIFT 5 #define SWD_DCRYPT_BITS 32 #define SWD_DCRYPT_MASK (SWD_DCRYPT_BITS - 1) #define SWD_DCRYPT_OFF(x) ((x) >> SWD_DCRYPT_SHIFT) #define SWD_DCRYPT_BIT(x) ((x) & SWD_DCRYPT_MASK) #define SWD_DCRYPT_SIZE(x) (SWD_DCRYPT_OFF((x) + SWD_DCRYPT_MASK) * sizeof(u_int32_t)) u_int32_t *swd_decrypt; /* bitmap for decryption */ struct swap_key *swd_keys; /* keys for different parts */ #endif }; /* * swap device priority entry; the list is kept sorted on `spi_priority'. */ struct swappri { int spi_priority; /* priority */ TAILQ_HEAD(spi_swapdev, swapdev) spi_swapdev; /* tailq of swapdevs at this priority */ LIST_ENTRY(swappri) spi_swappri; /* global list of pri's */ }; /* * The following two structures are used to keep track of data transfers * on swap devices associated with regular files. * NOTE: this code is more or less a copy of vnd.c; we use the same * structure names here to ease porting.. */ struct vndxfer { struct buf *vx_bp; /* Pointer to parent buffer */ struct swapdev *vx_sdp; int vx_error; int vx_pending; /* # of pending aux buffers */ int vx_flags; #define VX_BUSY 1 #define VX_DEAD 2 }; struct vndbuf { struct buf vb_buf; struct vndxfer *vb_vnx; struct task vb_task; }; /* * We keep a of pool vndbuf's and vndxfer structures. */ struct pool vndxfer_pool; struct pool vndbuf_pool; /* * local variables */ struct extent *swapmap; /* controls the mapping of /dev/drum */ /* list of all active swap devices [by priority] */ LIST_HEAD(swap_priority, swappri); struct swap_priority swap_priority; /* [S] */ /* locks */ struct mutex uvm_swap_data_lock = MUTEX_INITIALIZER(IPL_NONE); struct rwlock swap_syscall_lock = RWLOCK_INITIALIZER("swplk"); struct mutex oommtx = MUTEX_INITIALIZER(IPL_VM); struct vm_page *oompps[SWCLUSTPAGES]; int oom = 0; /* * prototypes */ void swapdrum_add(struct swapdev *, int); struct swapdev *swapdrum_getsdp(int); struct swapdev *swaplist_find(struct vnode *, int); void swaplist_insert(struct swapdev *, struct swappri *, int); void swaplist_trim(void); int swap_on(struct proc *, struct swapdev *); int swap_off(struct proc *, struct swapdev *); void sw_reg_strategy(struct swapdev *, struct buf *, int); void sw_reg_iodone(struct buf *); void sw_reg_iodone_internal(void *); void sw_reg_start(struct swapdev *); int uvm_swap_io(struct vm_page **, int, int, int); void swapmount(void); int uvm_swap_allocpages(struct vm_page **, int, int); #ifdef UVM_SWAP_ENCRYPT /* for swap encrypt */ void uvm_swap_markdecrypt(struct swapdev *, int, int, int); boolean_t uvm_swap_needdecrypt(struct swapdev *, int); void uvm_swap_initcrypt(struct swapdev *, int); #endif /* * uvm_swap_init: init the swap system data structures and locks * * => called at boot time from init_main.c after the filesystems * are brought up (which happens after uvm_init()) */ void uvm_swap_init(void) { int error; /* * first, init the swap list, its counter, and its lock. * then get a handle on the vnode for /dev/drum by using * the its dev_t number ("swapdev", from MD conf.c). */ LIST_INIT(&swap_priority); uvmexp.nswapdev = 0; if (!swapdev_vp && bdevvp(swapdev, &swapdev_vp)) panic("uvm_swap_init: can't get vnode for swap device"); /* * create swap block extent to map /dev/drum. The extent spans * 1 to INT_MAX allows 2 gigablocks of swap space. Note that * block 0 is reserved (used to indicate an allocation failure, * or no allocation). */ swapmap = extent_create("swapmap", 1, INT_MAX, M_VMSWAP, 0, 0, EX_NOWAIT); if (swapmap == 0) panic("uvm_swap_init: extent_create failed"); /* allocate pools for structures used for swapping to files. */ pool_init(&vndxfer_pool, sizeof(struct vndxfer), 0, IPL_BIO, 0, "swp vnx", NULL); pool_init(&vndbuf_pool, sizeof(struct vndbuf), 0, IPL_BIO, 0, "swp vnd", NULL); /* allocate pages for OOM situations. */ error = uvm_swap_allocpages(oompps, SWCLUSTPAGES, UVM_PLA_NOWAIT); KASSERT(error == 0); /* Setup the initial swap partition */ swapmount(); } #ifdef UVM_SWAP_ENCRYPT void uvm_swap_initcrypt_all(void) { struct swapdev *sdp; struct swappri *spp; int npages; LIST_FOREACH(spp, &swap_priority, spi_swappri) { TAILQ_FOREACH(sdp, &spp->spi_swapdev, swd_next) { if (sdp->swd_decrypt == NULL) { npages = dbtob((uint64_t)sdp->swd_nblks) >> PAGE_SHIFT; uvm_swap_initcrypt(sdp, npages); } } } } void uvm_swap_initcrypt(struct swapdev *sdp, int npages) { /* * keep information if a page needs to be decrypted when we get it * from the swap device. * We cannot chance a malloc later, if we are doing ASYNC puts, * we may not call malloc with M_WAITOK. This consumes only * 8KB memory for a 256MB swap partition. */ sdp->swd_decrypt = malloc(SWD_DCRYPT_SIZE(npages), M_VMSWAP, M_WAITOK|M_ZERO); sdp->swd_keys = mallocarray(SWD_KEY_SIZE(npages), sizeof(struct swap_key), M_VMSWAP, M_WAITOK|M_ZERO); } #endif /* UVM_SWAP_ENCRYPT */ int uvm_swap_allocpages(struct vm_page **pps, int npages, int flags) { struct pglist pgl; int error, i; KASSERT(npages <= SWCLUSTPAGES); TAILQ_INIT(&pgl); again: error = uvm_pglistalloc(npages * PAGE_SIZE, dma_constraint.ucr_low, dma_constraint.ucr_high, 0, 0, &pgl, npages, flags); if (error && (curproc == uvm.pagedaemon_proc)) { mtx_enter(&oommtx); if (oom) { msleep_nsec(&oom, &oommtx, PVM | PNORELOCK, "oom", INFSLP); goto again; } oom = 1; for (i = 0; i < npages; i++) { pps[i] = oompps[i]; atomic_setbits_int(&pps[i]->pg_flags, PG_BUSY); } mtx_leave(&oommtx); return 0; } if (error) return error; for (i = 0; i < npages; i++) { pps[i] = TAILQ_FIRST(&pgl); /* *sigh* */ atomic_setbits_int(&pps[i]->pg_flags, PG_BUSY); TAILQ_REMOVE(&pgl, pps[i], pageq); } return 0; } void uvm_swap_freepages(struct vm_page **pps, int npages) { int i; if (pps[0] == oompps[0]) { for (i = 0; i < npages; i++) uvm_pageclean(pps[i]); mtx_enter(&oommtx); KASSERT(oom == 1); oom = 0; mtx_leave(&oommtx); wakeup(&oom); return; } uvm_lock_pageq(); for (i = 0; i < npages; i++) uvm_pagefree(pps[i]); uvm_unlock_pageq(); } #ifdef UVM_SWAP_ENCRYPT /* * Mark pages on the swap device for later decryption */ void uvm_swap_markdecrypt(struct swapdev *sdp, int startslot, int npages, int decrypt) { int pagestart, i; int off, bit; if (!sdp) return; pagestart = startslot - sdp->swd_drumoffset; for (i = 0; i < npages; i++, pagestart++) { off = SWD_DCRYPT_OFF(pagestart); bit = SWD_DCRYPT_BIT(pagestart); if (decrypt) /* pages read need decryption */ sdp->swd_decrypt[off] |= 1 << bit; else /* pages read do not need decryption */ sdp->swd_decrypt[off] &= ~(1 << bit); } } /* * Check if the page that we got from disk needs to be decrypted */ boolean_t uvm_swap_needdecrypt(struct swapdev *sdp, int off) { if (!sdp) return FALSE; off -= sdp->swd_drumoffset; return sdp->swd_decrypt[SWD_DCRYPT_OFF(off)] & (1 << SWD_DCRYPT_BIT(off)) ? TRUE : FALSE; } void uvm_swap_finicrypt_all(void) { struct swapdev *sdp; struct swappri *spp; struct swap_key *key; unsigned int nkeys; LIST_FOREACH(spp, &swap_priority, spi_swappri) { TAILQ_FOREACH(sdp, &spp->spi_swapdev, swd_next) { if (sdp->swd_decrypt == NULL) continue; nkeys = dbtob((uint64_t)sdp->swd_nblks) >> PAGE_SHIFT; key = sdp->swd_keys + (SWD_KEY_SIZE(nkeys) - 1); do { if (key->refcount != 0) swap_key_delete(key); } while (key-- != sdp->swd_keys); } } } #endif /* UVM_SWAP_ENCRYPT */ /* * swaplist functions: functions that operate on the list of swap * devices on the system. */ /* * swaplist_insert: insert swap device "sdp" into the global list * * => caller must hold both swap_syscall_lock and uvm_swap_data_lock * => caller must provide a newly allocated swappri structure (we will * FREE it if we don't need it... this it to prevent allocation * blocking here while adding swap) */ void swaplist_insert(struct swapdev *sdp, struct swappri *newspp, int priority) { struct swappri *spp, *pspp; KASSERT(rw_write_held(&swap_syscall_lock)); MUTEX_ASSERT_LOCKED(&uvm_swap_data_lock); /* * find entry at or after which to insert the new device. */ pspp = NULL; LIST_FOREACH(spp, &swap_priority, spi_swappri) { if (priority <= spp->spi_priority) break; pspp = spp; } /* * new priority? */ if (spp == NULL || spp->spi_priority != priority) { spp = newspp; /* use newspp! */ spp->spi_priority = priority; TAILQ_INIT(&spp->spi_swapdev); if (pspp) LIST_INSERT_AFTER(pspp, spp, spi_swappri); else LIST_INSERT_HEAD(&swap_priority, spp, spi_swappri); } else { /* we don't need a new priority structure, free it */ free(newspp, M_VMSWAP, sizeof(*newspp)); } /* * priority found (or created). now insert on the priority's * tailq list and bump the total number of swapdevs. */ sdp->swd_priority = priority; TAILQ_INSERT_TAIL(&spp->spi_swapdev, sdp, swd_next); uvmexp.nswapdev++; } /* * swaplist_find: find and optionally remove a swap device from the * global list. * * => caller must hold both swap_syscall_lock and uvm_swap_data_lock * => we return the swapdev we found (and removed) */ struct swapdev * swaplist_find(struct vnode *vp, boolean_t remove) { struct swapdev *sdp; struct swappri *spp; KASSERT(rw_write_held(&swap_syscall_lock)); MUTEX_ASSERT_LOCKED(&uvm_swap_data_lock); /* * search the lists for the requested vp */ LIST_FOREACH(spp, &swap_priority, spi_swappri) { TAILQ_FOREACH(sdp, &spp->spi_swapdev, swd_next) { if (sdp->swd_vp != vp) continue; if (remove) { TAILQ_REMOVE(&spp->spi_swapdev, sdp, swd_next); uvmexp.nswapdev--; } return (sdp); } } return (NULL); } /* * swaplist_trim: scan priority list for empty priority entries and kill * them. * * => caller must hold both swap_syscall_lock and uvm_swap_data_lock */ void swaplist_trim(void) { struct swappri *spp, *nextspp; KASSERT(rw_write_held(&swap_syscall_lock)); MUTEX_ASSERT_LOCKED(&uvm_swap_data_lock); LIST_FOREACH_SAFE(spp, &swap_priority, spi_swappri, nextspp) { if (!TAILQ_EMPTY(&spp->spi_swapdev)) continue; LIST_REMOVE(spp, spi_swappri); free(spp, M_VMSWAP, sizeof(*spp)); } } /* * swapdrum_add: add a "swapdev"'s blocks into /dev/drum's area. * * => caller must hold swap_syscall_lock * => uvm_swap_data_lock should be unlocked (we may sleep) */ void swapdrum_add(struct swapdev *sdp, int npages) { u_long result; if (extent_alloc(swapmap, npages, EX_NOALIGN, 0, EX_NOBOUNDARY, EX_WAITOK, &result)) panic("swapdrum_add"); sdp->swd_drumoffset = result; sdp->swd_drumsize = npages; } /* * swapdrum_getsdp: given a page offset in /dev/drum, convert it back * to the "swapdev" that maps that section of the drum. * * => each swapdev takes one big contig chunk of the drum * => caller must hold uvm_swap_data_lock */ struct swapdev * swapdrum_getsdp(int pgno) { struct swapdev *sdp; struct swappri *spp; MUTEX_ASSERT_LOCKED(&uvm_swap_data_lock); LIST_FOREACH(spp, &swap_priority, spi_swappri) { TAILQ_FOREACH(sdp, &spp->spi_swapdev, swd_next) { if (pgno >= sdp->swd_drumoffset && pgno < (sdp->swd_drumoffset + sdp->swd_drumsize)) { return sdp; } } } return NULL; } /* * sys_swapctl: main entry point for swapctl(2) system call * [with two helper functions: swap_on and swap_off] */ int sys_swapctl(struct proc *p, void *v, register_t *retval) { struct sys_swapctl_args /* { syscallarg(int) cmd; syscallarg(void *) arg; syscallarg(int) misc; } */ *uap = (struct sys_swapctl_args *)v; struct vnode *vp; struct nameidata nd; struct swappri *spp; struct swapdev *sdp; struct swapent *sep; char userpath[MAXPATHLEN]; size_t len; int count, error, misc; int priority; misc = SCARG(uap, misc); if ((error = pledge_swapctl(p, SCARG(uap, cmd)))) return error; /* * ensure serialized syscall access by grabbing the swap_syscall_lock */ rw_enter_write(&swap_syscall_lock); /* * we handle the non-priv NSWAP and STATS request first. * * SWAP_NSWAP: return number of config'd swap devices * [can also be obtained with uvmexp sysctl] */ if (SCARG(uap, cmd) == SWAP_NSWAP) { *retval = uvmexp.nswapdev; error = 0; goto out; } /* * SWAP_STATS: get stats on current # of configured swap devs * * note that the swap_priority list can't change as long * as we are holding the swap_syscall_lock. we don't want * to grab the uvm_swap_data_lock because we may fault&sleep during * copyout() and we don't want to be holding that lock then! */ if (SCARG(uap, cmd) == SWAP_STATS) { sep = (struct swapent *)SCARG(uap, arg); count = 0; LIST_FOREACH(spp, &swap_priority, spi_swappri) { TAILQ_FOREACH(sdp, &spp->spi_swapdev, swd_next) { if (count >= misc) continue; sdp->swd_inuse = btodb((u_int64_t)sdp->swd_npginuse << PAGE_SHIFT); error = copyout(&sdp->swd_se, sep, sizeof(struct swapent)); if (error) goto out; /* now copy out the path if necessary */ error = copyoutstr(sdp->swd_path, sep->se_path, sizeof(sep->se_path), NULL); if (error) goto out; count++; sep++; } } *retval = count; error = 0; goto out; } /* all other requests require superuser privs. verify. */ if ((error = suser(p))) goto out; /* * at this point we expect a path name in arg. we will * use namei() to gain a vnode reference (vref), and lock * the vnode (VOP_LOCK). */ error = copyinstr(SCARG(uap, arg), userpath, sizeof(userpath), &len); if (error) goto out; disk_map(userpath, userpath, sizeof(userpath), DM_OPENBLCK); NDINIT(&nd, LOOKUP, FOLLOW|LOCKLEAF, UIO_SYSSPACE, userpath, p); if ((error = namei(&nd))) goto out; vp = nd.ni_vp; /* note: "vp" is referenced and locked */ error = 0; /* assume no error */ switch(SCARG(uap, cmd)) { case SWAP_DUMPDEV: if (vp->v_type != VBLK) { error = ENOTBLK; break; } dumpdev = vp->v_rdev; break; case SWAP_CTL: /* * get new priority, remove old entry (if any) and then * reinsert it in the correct place. finally, prune out * any empty priority structures. */ priority = SCARG(uap, misc); spp = malloc(sizeof *spp, M_VMSWAP, M_WAITOK); mtx_enter(&uvm_swap_data_lock); if ((sdp = swaplist_find(vp, 1)) == NULL) { error = ENOENT; } else { swaplist_insert(sdp, spp, priority); swaplist_trim(); } mtx_leave(&uvm_swap_data_lock); if (error) free(spp, M_VMSWAP, sizeof(*spp)); break; case SWAP_ON: /* * If the device is a regular file, make sure the filesystem * can be used for swapping. */ if (vp->v_type == VREG && (vp->v_mount->mnt_flag & MNT_SWAPPABLE) == 0) { error = ENOTSUP; break; } /* * check for duplicates. if none found, then insert a * dummy entry on the list to prevent someone else from * trying to enable this device while we are working on * it. */ priority = SCARG(uap, misc); sdp = malloc(sizeof *sdp, M_VMSWAP, M_WAITOK|M_ZERO); spp = malloc(sizeof *spp, M_VMSWAP, M_WAITOK); sdp->swd_flags = SWF_FAKE; /* placeholder only */ sdp->swd_vp = vp; sdp->swd_dev = (vp->v_type == VBLK) ? vp->v_rdev : NODEV; /* * XXX Is NFS elaboration necessary? */ if (vp->v_type == VREG) { sdp->swd_cred = crdup(p->p_ucred); } mtx_enter(&uvm_swap_data_lock); if (swaplist_find(vp, 0) != NULL) { error = EBUSY; mtx_leave(&uvm_swap_data_lock); if (vp->v_type == VREG) { crfree(sdp->swd_cred); } free(sdp, M_VMSWAP, sizeof *sdp); free(spp, M_VMSWAP, sizeof *spp); break; } swaplist_insert(sdp, spp, priority); mtx_leave(&uvm_swap_data_lock); sdp->swd_pathlen = len; sdp->swd_path = malloc(sdp->swd_pathlen, M_VMSWAP, M_WAITOK); strlcpy(sdp->swd_path, userpath, len); /* * we've now got a FAKE placeholder in the swap list. * now attempt to enable swap on it. if we fail, undo * what we've done and kill the fake entry we just inserted. * if swap_on is a success, it will clear the SWF_FAKE flag */ if ((error = swap_on(p, sdp)) != 0) { mtx_enter(&uvm_swap_data_lock); (void) swaplist_find(vp, 1); /* kill fake entry */ swaplist_trim(); mtx_leave(&uvm_swap_data_lock); if (vp->v_type == VREG) { crfree(sdp->swd_cred); } free(sdp->swd_path, M_VMSWAP, sdp->swd_pathlen); free(sdp, M_VMSWAP, sizeof(*sdp)); break; } break; case SWAP_OFF: mtx_enter(&uvm_swap_data_lock); if ((sdp = swaplist_find(vp, 0)) == NULL) { mtx_leave(&uvm_swap_data_lock); error = ENXIO; break; } /* * If a device isn't in use or enabled, we * can't stop swapping from it (again). */ if ((sdp->swd_flags & (SWF_INUSE|SWF_ENABLE)) == 0) { mtx_leave(&uvm_swap_data_lock); error = EBUSY; break; } /* * do the real work. */ error = swap_off(p, sdp); break; default: error = EINVAL; } /* done! release the ref gained by namei() and unlock. */ vput(vp); out: rw_exit_write(&swap_syscall_lock); return (error); } /* * swap_on: attempt to enable a swapdev for swapping. note that the * swapdev is already on the global list, but disabled (marked * SWF_FAKE). * * => we avoid the start of the disk (to protect disk labels) * => caller should leave uvm_swap_data_lock unlocked, we may lock it * if needed. */ int swap_on(struct proc *p, struct swapdev *sdp) { struct vnode *vp; int error, npages, nblocks, size; long addr; struct vattr va; #if defined(NFSCLIENT) extern const struct vops nfs_vops; #endif /* defined(NFSCLIENT) */ dev_t dev; /* * we want to enable swapping on sdp. the swd_vp contains * the vnode we want (locked and ref'd), and the swd_dev * contains the dev_t of the file, if it a block device. */ vp = sdp->swd_vp; dev = sdp->swd_dev; #if NVND > 0 /* no swapping to vnds. */ if (bdevsw[major(dev)].d_strategy == vndstrategy) return (EOPNOTSUPP); #endif /* * open the swap file (mostly useful for block device files to * let device driver know what is up). * * we skip the open/close for root on swap because the root * has already been opened when root was mounted (mountroot). */ if (vp != rootvp) { if ((error = VOP_OPEN(vp, FREAD|FWRITE, p->p_ucred, p))) return (error); } /* XXX this only works for block devices */ /* * we now need to determine the size of the swap area. for * block specials we can call the d_psize function. * for normal files, we must stat [get attrs]. * * we put the result in nblks. * for normal files, we also want the filesystem block size * (which we get with statfs). */ switch (vp->v_type) { case VBLK: if (bdevsw[major(dev)].d_psize == 0 || (nblocks = (*bdevsw[major(dev)].d_psize)(dev)) == -1) { error = ENXIO; goto bad; } break; case VREG: if ((error = VOP_GETATTR(vp, &va, p->p_ucred, p))) goto bad; nblocks = (int)btodb(va.va_size); if ((error = VFS_STATFS(vp->v_mount, &vp->v_mount->mnt_stat, p)) != 0) goto bad; sdp->swd_bsize = vp->v_mount->mnt_stat.f_iosize; /* * limit the max # of outstanding I/O requests we issue * at any one time. take it easy on NFS servers. */ #if defined(NFSCLIENT) if (vp->v_op == &nfs_vops) sdp->swd_maxactive = 2; /* XXX */ else #endif /* defined(NFSCLIENT) */ sdp->swd_maxactive = 8; /* XXX */ bufq_init(&sdp->swd_bufq, BUFQ_FIFO); break; default: error = ENXIO; goto bad; } /* * save nblocks in a safe place and convert to pages. */ sdp->swd_nblks = nblocks; npages = dbtob((u_int64_t)nblocks) >> PAGE_SHIFT; /* * for block special files, we want to make sure that leave * the disklabel and bootblocks alone, so we arrange to skip * over them (arbitrarily choosing to skip PAGE_SIZE bytes). * note that because of this the "size" can be less than the * actual number of blocks on the device. */ if (vp->v_type == VBLK) { /* we use pages 1 to (size - 1) [inclusive] */ size = npages - 1; addr = 1; } else { /* we use pages 0 to (size - 1) [inclusive] */ size = npages; addr = 0; } /* * make sure we have enough blocks for a reasonable sized swap * area. we want at least one page. */ if (size < 1) { error = EINVAL; goto bad; } /* * now we need to allocate a blist to manage this swap device */ sdp->swd_blist = blist_create(npages); /* mark all expect the `saved' region free. */ blist_free(sdp->swd_blist, addr, size); #ifdef HIBERNATE /* * Lock down the last region of primary disk swap, in case * hibernate needs to place a signature there. */ if (dev == swdevt[0].sw_dev && vp->v_type == VBLK && size > 3 ) { if (blist_fill(sdp->swd_blist, npages - 1, 1) != 1) panic("hibernate reserve"); } #endif /* add a ref to vp to reflect usage as a swap device. */ vref(vp); #ifdef UVM_SWAP_ENCRYPT if (uvm_doswapencrypt) uvm_swap_initcrypt(sdp, npages); #endif /* now add the new swapdev to the drum and enable. */ swapdrum_add(sdp, npages); sdp->swd_npages = size; mtx_enter(&uvm_swap_data_lock); sdp->swd_flags &= ~SWF_FAKE; /* going live */ sdp->swd_flags |= (SWF_INUSE|SWF_ENABLE); uvmexp.swpages += size; mtx_leave(&uvm_swap_data_lock); return (0); /* * failure: clean up and return error. */ bad: if (vp != rootvp) (void)VOP_CLOSE(vp, FREAD|FWRITE, p->p_ucred, p); return (error); } /* * swap_off: stop swapping on swapdev * * => swap data should be locked, we will unlock. */ int swap_off(struct proc *p, struct swapdev *sdp) { int npages = sdp->swd_npages; int error = 0; KASSERT(rw_write_held(&swap_syscall_lock)); MUTEX_ASSERT_LOCKED(&uvm_swap_data_lock); /* disable the swap area being removed */ sdp->swd_flags &= ~SWF_ENABLE; mtx_leave(&uvm_swap_data_lock); /* * the idea is to find all the pages that are paged out to this * device, and page them all in. in uvm, swap-backed pageable * memory can take two forms: aobjs and anons. call the * swapoff hook for each subsystem to bring in pages. */ if (uao_swap_off(sdp->swd_drumoffset, sdp->swd_drumoffset + sdp->swd_drumsize) || amap_swap_off(sdp->swd_drumoffset, sdp->swd_drumoffset + sdp->swd_drumsize)) { error = ENOMEM; } else if (sdp->swd_npginuse > sdp->swd_npgbad) { error = EBUSY; } if (error) { mtx_enter(&uvm_swap_data_lock); sdp->swd_flags |= SWF_ENABLE; mtx_leave(&uvm_swap_data_lock); return error; } /* * done with the vnode and saved creds. * drop our ref on the vnode before calling VOP_CLOSE() * so that spec_close() can tell if this is the last close. */ if (sdp->swd_vp->v_type == VREG) { crfree(sdp->swd_cred); } vrele(sdp->swd_vp); if (sdp->swd_vp != rootvp) { (void) VOP_CLOSE(sdp->swd_vp, FREAD|FWRITE, p->p_ucred, p); } mtx_enter(&uvm_swap_data_lock); uvmexp.swpages -= npages; if (swaplist_find(sdp->swd_vp, 1) == NULL) panic("swap_off: swapdev not in list"); swaplist_trim(); mtx_leave(&uvm_swap_data_lock); /* * free all resources! */ extent_free(swapmap, sdp->swd_drumoffset, sdp->swd_drumsize, EX_WAITOK); blist_destroy(sdp->swd_blist); /* free sdp->swd_path ? */ free(sdp, M_VMSWAP, sizeof(*sdp)); return (0); } /* * /dev/drum interface and i/o functions */ /* * swstrategy: perform I/O on the drum * * => we must map the i/o request from the drum to the correct swapdev. */ void swstrategy(struct buf *bp) { struct swapdev *sdp; int s, pageno, bn; /* * convert block number to swapdev. note that swapdev can't * be yanked out from under us because we are holding resources * in it (i.e. the blocks we are doing I/O on). */ pageno = dbtob((u_int64_t)bp->b_blkno) >> PAGE_SHIFT; mtx_enter(&uvm_swap_data_lock); sdp = swapdrum_getsdp(pageno); mtx_leave(&uvm_swap_data_lock); if (sdp == NULL) { bp->b_error = EINVAL; bp->b_flags |= B_ERROR; s = splbio(); biodone(bp); splx(s); return; } /* convert drum page number to block number on this swapdev. */ pageno -= sdp->swd_drumoffset; /* page # on swapdev */ bn = btodb((u_int64_t)pageno << PAGE_SHIFT); /* convert to diskblock */ /* * for block devices we finish up here. * for regular files we have to do more work which we delegate * to sw_reg_strategy(). */ switch (sdp->swd_vp->v_type) { default: panic("swstrategy: vnode type 0x%x", sdp->swd_vp->v_type); case VBLK: /* * must convert "bp" from an I/O on /dev/drum to an I/O * on the swapdev (sdp). */ s = splbio(); buf_replacevnode(bp, sdp->swd_vp); bp->b_blkno = bn; splx(s); VOP_STRATEGY(bp->b_vp, bp); return; case VREG: /* delegate to sw_reg_strategy function. */ sw_reg_strategy(sdp, bp, bn); return; } /* NOTREACHED */ } /* * sw_reg_strategy: handle swap i/o to regular files */ void sw_reg_strategy(struct swapdev *sdp, struct buf *bp, int bn) { struct vnode *vp; struct vndxfer *vnx; daddr_t nbn; caddr_t addr; off_t byteoff; int s, off, nra, error, sz, resid; /* * allocate a vndxfer head for this transfer and point it to * our buffer. */ vnx = pool_get(&vndxfer_pool, PR_WAITOK); vnx->vx_flags = VX_BUSY; vnx->vx_error = 0; vnx->vx_pending = 0; vnx->vx_bp = bp; vnx->vx_sdp = sdp; /* * setup for main loop where we read filesystem blocks into * our buffer. */ error = 0; bp->b_resid = bp->b_bcount; /* nothing transferred yet! */ addr = bp->b_data; /* current position in buffer */ byteoff = dbtob((u_int64_t)bn); for (resid = bp->b_resid; resid; resid -= sz) { struct vndbuf *nbp; /* * translate byteoffset into block number. return values: * vp = vnode of underlying device * nbn = new block number (on underlying vnode dev) * nra = num blocks we can read-ahead (excludes requested * block) */ nra = 0; error = VOP_BMAP(sdp->swd_vp, byteoff / sdp->swd_bsize, &vp, &nbn, &nra); if (error == 0 && nbn == -1) { /* * this used to just set error, but that doesn't * do the right thing. Instead, it causes random * memory errors. The panic() should remain until * this condition doesn't destabilize the system. */ #if 1 panic("sw_reg_strategy: swap to sparse file"); #else error = EIO; /* failure */ #endif } /* * punt if there was an error or a hole in the file. * we must wait for any i/o ops we have already started * to finish before returning. * * XXX we could deal with holes here but it would be * a hassle (in the write case). */ if (error) { s = splbio(); vnx->vx_error = error; /* pass error up */ goto out; } /* * compute the size ("sz") of this transfer (in bytes). */ off = byteoff % sdp->swd_bsize; sz = (1 + nra) * sdp->swd_bsize - off; if (sz > resid) sz = resid; /* * now get a buf structure. note that the vb_buf is * at the front of the nbp structure so that you can * cast pointers between the two structure easily. */ nbp = pool_get(&vndbuf_pool, PR_WAITOK); nbp->vb_buf.b_flags = bp->b_flags | B_CALL; nbp->vb_buf.b_bcount = sz; nbp->vb_buf.b_bufsize = sz; nbp->vb_buf.b_error = 0; nbp->vb_buf.b_data = addr; nbp->vb_buf.b_bq = NULL; nbp->vb_buf.b_blkno = nbn + btodb(off); nbp->vb_buf.b_proc = bp->b_proc; nbp->vb_buf.b_iodone = sw_reg_iodone; nbp->vb_buf.b_vp = NULLVP; nbp->vb_buf.b_vnbufs.le_next = NOLIST; LIST_INIT(&nbp->vb_buf.b_dep); /* * set b_dirtyoff/end and b_validoff/end. this is * required by the NFS client code (otherwise it will * just discard our I/O request). */ if (bp->b_dirtyend == 0) { nbp->vb_buf.b_dirtyoff = 0; nbp->vb_buf.b_dirtyend = sz; } else { nbp->vb_buf.b_dirtyoff = max(0, bp->b_dirtyoff - (bp->b_bcount-resid)); nbp->vb_buf.b_dirtyend = min(sz, max(0, bp->b_dirtyend - (bp->b_bcount-resid))); } if (bp->b_validend == 0) { nbp->vb_buf.b_validoff = 0; nbp->vb_buf.b_validend = sz; } else { nbp->vb_buf.b_validoff = max(0, bp->b_validoff - (bp->b_bcount-resid)); nbp->vb_buf.b_validend = min(sz, max(0, bp->b_validend - (bp->b_bcount-resid))); } /* patch it back to the vnx */ nbp->vb_vnx = vnx; task_set(&nbp->vb_task, sw_reg_iodone_internal, nbp); s = splbio(); if (vnx->vx_error != 0) { pool_put(&vndbuf_pool, nbp); goto out; } vnx->vx_pending++; /* assoc new buffer with underlying vnode */ bgetvp(vp, &nbp->vb_buf); /* start I/O if we are not over our limit */ bufq_queue(&sdp->swd_bufq, &nbp->vb_buf); sw_reg_start(sdp); splx(s); /* * advance to the next I/O */ byteoff += sz; addr += sz; } s = splbio(); out: /* Arrive here at splbio */ vnx->vx_flags &= ~VX_BUSY; if (vnx->vx_pending == 0) { if (vnx->vx_error != 0) { bp->b_error = vnx->vx_error; bp->b_flags |= B_ERROR; } pool_put(&vndxfer_pool, vnx); biodone(bp); } splx(s); } /* sw_reg_start: start an I/O request on the requested swapdev. */ void sw_reg_start(struct swapdev *sdp) { struct buf *bp; /* XXX: recursion control */ if ((sdp->swd_flags & SWF_BUSY) != 0) return; sdp->swd_flags |= SWF_BUSY; while (sdp->swd_active < sdp->swd_maxactive) { bp = bufq_dequeue(&sdp->swd_bufq); if (bp == NULL) break; sdp->swd_active++; if ((bp->b_flags & B_READ) == 0) bp->b_vp->v_numoutput++; VOP_STRATEGY(bp->b_vp, bp); } sdp->swd_flags &= ~SWF_BUSY; } /* * sw_reg_iodone: one of our i/o's has completed and needs post-i/o cleanup * * => note that we can recover the vndbuf struct by casting the buf ptr * * XXX: * We only put this onto a taskq here, because of the maxactive game since * it basically requires us to call back into VOP_STRATEGY() (where we must * be able to sleep) via sw_reg_start(). */ void sw_reg_iodone(struct buf *bp) { struct vndbuf *vbp = (struct vndbuf *)bp; task_add(systq, &vbp->vb_task); } void sw_reg_iodone_internal(void *xvbp) { struct vndbuf *vbp = xvbp; struct vndxfer *vnx = vbp->vb_vnx; struct buf *pbp = vnx->vx_bp; /* parent buffer */ struct swapdev *sdp = vnx->vx_sdp; int resid, s; s = splbio(); resid = vbp->vb_buf.b_bcount - vbp->vb_buf.b_resid; pbp->b_resid -= resid; vnx->vx_pending--; /* pass error upward */ if (vbp->vb_buf.b_error) vnx->vx_error = vbp->vb_buf.b_error; /* disassociate this buffer from the vnode (if any). */ if (vbp->vb_buf.b_vp != NULL) { brelvp(&vbp->vb_buf); } /* kill vbp structure */ pool_put(&vndbuf_pool, vbp); /* * wrap up this transaction if it has run to completion or, in * case of an error, when all auxiliary buffers have returned. */ if (vnx->vx_error != 0) { /* pass error upward */ pbp->b_flags |= B_ERROR; pbp->b_error = vnx->vx_error; if ((vnx->vx_flags & VX_BUSY) == 0 && vnx->vx_pending == 0) { pool_put(&vndxfer_pool, vnx); biodone(pbp); } } else if (pbp->b_resid == 0) { KASSERT(vnx->vx_pending == 0); if ((vnx->vx_flags & VX_BUSY) == 0) { pool_put(&vndxfer_pool, vnx); biodone(pbp); } } /* * done! start next swapdev I/O if one is pending */ sdp->swd_active--; sw_reg_start(sdp); splx(s); } /* * uvm_swap_alloc: allocate space on swap * * => allocation is done "round robin" down the priority list, as we * allocate in a priority we "rotate" the tail queue. * => space can be freed with uvm_swap_free * => we return the page slot number in /dev/drum (0 == invalid slot) * => we lock uvm_swap_data_lock * => XXXMRG: "LESSOK" INTERFACE NEEDED TO EXTENT SYSTEM */ int uvm_swap_alloc(int *nslots, boolean_t lessok) { struct swapdev *sdp; struct swappri *spp; /* * no swap devices configured yet? definite failure. */ if (uvmexp.nswapdev < 1) return 0; /* * lock data lock, convert slots into blocks, and enter loop */ KERNEL_ASSERT_LOCKED(); mtx_enter(&uvm_swap_data_lock); ReTry: /* XXXMRG */ LIST_FOREACH(spp, &swap_priority, spi_swappri) { TAILQ_FOREACH(sdp, &spp->spi_swapdev, swd_next) { swblk_t result; /* if it's not enabled, then we can't swap from it */ if ((sdp->swd_flags & SWF_ENABLE) == 0) continue; if (sdp->swd_npginuse + *nslots > sdp->swd_npages) continue; result = blist_alloc(sdp->swd_blist, *nslots); if (result == SWAPBLK_NONE) { continue; } KASSERT(result < sdp->swd_drumsize); /* * successful allocation! now rotate the tailq. */ TAILQ_REMOVE(&spp->spi_swapdev, sdp, swd_next); TAILQ_INSERT_TAIL(&spp->spi_swapdev, sdp, swd_next); sdp->swd_npginuse += *nslots; uvmexp.swpginuse += *nslots; mtx_leave(&uvm_swap_data_lock); /* done! return drum slot number */ return result + sdp->swd_drumoffset; } } /* XXXMRG: BEGIN HACK */ if (*nslots > 1 && lessok) { *nslots = 1; /* XXXMRG: ugh! blist should support this for us */ goto ReTry; } /* XXXMRG: END HACK */ mtx_leave(&uvm_swap_data_lock); return 0; /* failed */ } /* * uvm_swapisfull: return true if all of available swap is allocated * and in use. */ int uvm_swapisfull(void) { int result; mtx_enter(&uvm_swap_data_lock); KASSERT(uvmexp.swpgonly <= uvmexp.swpages); result = (uvmexp.swpgonly == uvmexp.swpages); mtx_leave(&uvm_swap_data_lock); return result; } /* * uvm_swap_markbad: keep track of swap ranges where we've had i/o errors * * => we lock uvm_swap_data_lock */ void uvm_swap_markbad(int startslot, int nslots) { struct swapdev *sdp; mtx_enter(&uvm_swap_data_lock); sdp = swapdrum_getsdp(startslot); if (sdp != NULL) { /* * we just keep track of how many pages have been marked bad * in this device, to make everything add up in swap_off(). * we assume here that the range of slots will all be within * one swap device. */ sdp->swd_npgbad += nslots; } mtx_leave(&uvm_swap_data_lock); } /* * uvm_swap_free: free swap slots * * => this can be all or part of an allocation made by uvm_swap_alloc * => we lock uvm_swap_data_lock */ void uvm_swap_free(int startslot, int nslots) { struct swapdev *sdp; /* * ignore attempts to free the "bad" slot. */ if (startslot == SWSLOT_BAD) { return; } /* * convert drum slot offset back to sdp, free the blocks * in the extent, and return. must hold pri lock to do * lookup and access the extent. */ KERNEL_LOCK(); mtx_enter(&uvm_swap_data_lock); sdp = swapdrum_getsdp(startslot); KASSERT(uvmexp.nswapdev >= 1); KASSERT(sdp != NULL); KASSERT(sdp->swd_npginuse >= nslots); blist_free(sdp->swd_blist, startslot - sdp->swd_drumoffset, nslots); sdp->swd_npginuse -= nslots; uvmexp.swpginuse -= nslots; mtx_leave(&uvm_swap_data_lock); #ifdef UVM_SWAP_ENCRYPT { int i; if (swap_encrypt_initialized) { /* Dereference keys */ for (i = 0; i < nslots; i++) if (uvm_swap_needdecrypt(sdp, startslot + i)) { struct swap_key *key; key = SWD_KEY(sdp, startslot + i); if (key->refcount != 0) SWAP_KEY_PUT(sdp, key); } /* Mark range as not decrypt */ uvm_swap_markdecrypt(sdp, startslot, nslots, 0); } } #endif /* UVM_SWAP_ENCRYPT */ KERNEL_UNLOCK(); } /* * uvm_swap_put: put any number of pages into a contig place on swap * * => can be sync or async */ int uvm_swap_put(int swslot, struct vm_page **ppsp, int npages, int flags) { int result; result = uvm_swap_io(ppsp, swslot, npages, B_WRITE | ((flags & PGO_SYNCIO) ? 0 : B_ASYNC)); return (result); } /* * uvm_swap_get: get a single page from swap * * => usually a sync op (from fault) */ int uvm_swap_get(struct vm_page *page, int swslot, int flags) { int result; atomic_inc_int(&uvmexp.nswget); KASSERT(flags & PGO_SYNCIO); if (swslot == SWSLOT_BAD) { return VM_PAGER_ERROR; } KERNEL_LOCK(); result = uvm_swap_io(&page, swslot, 1, B_READ); KERNEL_UNLOCK(); if (result == VM_PAGER_OK || result == VM_PAGER_PEND) { /* * this page is no longer only in swap. */ atomic_dec_int(&uvmexp.swpgonly); } return (result); } /* * uvm_swap_io: do an i/o operation to swap */ int uvm_swap_io(struct vm_page **pps, int startslot, int npages, int flags) { daddr_t startblk; struct buf *bp; vaddr_t kva; int result, s, mapinflags, pflag, bounce = 0, i; boolean_t write, async; vaddr_t bouncekva; struct vm_page *tpps[SWCLUSTPAGES]; int pdaemon = (curproc == uvm.pagedaemon_proc); #ifdef UVM_SWAP_ENCRYPT struct swapdev *sdp; int encrypt = 0; #endif KERNEL_ASSERT_LOCKED(); write = (flags & B_READ) == 0; async = (flags & B_ASYNC) != 0; /* convert starting drum slot to block number */ startblk = btodb((u_int64_t)startslot << PAGE_SHIFT); pflag = (async || pdaemon) ? PR_NOWAIT : PR_WAITOK; bp = pool_get(&bufpool, pflag | PR_ZERO); if (bp == NULL) return (VM_PAGER_AGAIN); /* * map the pages into the kernel (XXX: currently required * by buffer system). */ mapinflags = !write ? UVMPAGER_MAPIN_READ : UVMPAGER_MAPIN_WRITE; if (!async) mapinflags |= UVMPAGER_MAPIN_WAITOK; kva = uvm_pagermapin(pps, npages, mapinflags); if (kva == 0) { pool_put(&bufpool, bp); return (VM_PAGER_AGAIN); } #ifdef UVM_SWAP_ENCRYPT if (write) { /* * Check if we need to do swap encryption on old pages. * Later we need a different scheme, that swap encrypts * all pages of a process that had at least one page swap * encrypted. Then we might not need to copy all pages * in the cluster, and avoid the memory overheard in * swapping. */ if (uvm_doswapencrypt) encrypt = 1; } if (swap_encrypt_initialized || encrypt) { /* * we need to know the swap device that we are swapping to/from * to see if the pages need to be marked for decryption or * actually need to be decrypted. * XXX - does this information stay the same over the whole * execution of this function? */ mtx_enter(&uvm_swap_data_lock); sdp = swapdrum_getsdp(startslot); mtx_leave(&uvm_swap_data_lock); } /* * Check that we are dma capable for read (write always bounces * through the swapencrypt anyway... */ if (write && encrypt) { bounce = 1; /* bounce through swapencrypt always */ } else { #else { #endif for (i = 0; i < npages; i++) { if (VM_PAGE_TO_PHYS(pps[i]) < dma_constraint.ucr_low || VM_PAGE_TO_PHYS(pps[i]) > dma_constraint.ucr_high) { bounce = 1; break; } } } if (bounce) { int swmapflags, plaflags; /* We always need write access. */ swmapflags = UVMPAGER_MAPIN_READ; plaflags = UVM_PLA_NOWAIT; if (!async) { swmapflags |= UVMPAGER_MAPIN_WAITOK; plaflags = UVM_PLA_WAITOK; } if (uvm_swap_allocpages(tpps, npages, plaflags)) { pool_put(&bufpool, bp); uvm_pagermapout(kva, npages); return (VM_PAGER_AGAIN); } bouncekva = uvm_pagermapin(tpps, npages, swmapflags); if (bouncekva == 0) { pool_put(&bufpool, bp); uvm_pagermapout(kva, npages); uvm_swap_freepages(tpps, npages); return (VM_PAGER_AGAIN); } } /* encrypt to swap */ if (write && bounce) { int i, opages; caddr_t src, dst; u_int64_t block; src = (caddr_t) kva; dst = (caddr_t) bouncekva; block = startblk; for (i = 0; i < npages; i++) { #ifdef UVM_SWAP_ENCRYPT struct swap_key *key; if (encrypt) { key = SWD_KEY(sdp, startslot + i); SWAP_KEY_GET(sdp, key); /* add reference */ swap_encrypt(key, src, dst, block, PAGE_SIZE); block += btodb(PAGE_SIZE); } else { #else { #endif /* UVM_SWAP_ENCRYPT */ memcpy(dst, src, PAGE_SIZE); } /* this just tells async callbacks to free */ atomic_setbits_int(&tpps[i]->pg_flags, PQ_ENCRYPT); src += PAGE_SIZE; dst += PAGE_SIZE; } uvm_pagermapout(kva, npages); /* dispose of pages we dont use anymore */ opages = npages; uvm_pager_dropcluster(NULL, NULL, pps, &opages, PGO_PDFREECLUST); kva = bouncekva; } /* * prevent ASYNC reads. * uvm_swap_io is only called from uvm_swap_get, uvm_swap_get * assumes that all gets are SYNCIO. Just make sure here. * XXXARTUBC - might not be true anymore. */ if (!write) { flags &= ~B_ASYNC; async = 0; } /* * fill in the bp. we currently route our i/o through * /dev/drum's vnode [swapdev_vp]. */ bp->b_flags = B_BUSY | B_NOCACHE | B_RAW | (flags & (B_READ|B_ASYNC)); bp->b_proc = &proc0; /* XXX */ bp->b_vnbufs.le_next = NOLIST; if (bounce) bp->b_data = (caddr_t)bouncekva; else bp->b_data = (caddr_t)kva; bp->b_bq = NULL; bp->b_blkno = startblk; LIST_INIT(&bp->b_dep); s = splbio(); bp->b_vp = NULL; buf_replacevnode(bp, swapdev_vp); splx(s); bp->b_bufsize = bp->b_bcount = (long)npages << PAGE_SHIFT; /* * for pageouts we must set "dirtyoff" [NFS client code needs it]. * and we bump v_numoutput (counter of number of active outputs). */ if (write) { bp->b_dirtyoff = 0; bp->b_dirtyend = npages << PAGE_SHIFT; #ifdef UVM_SWAP_ENCRYPT /* mark the pages in the drum for decryption */ if (swap_encrypt_initialized) uvm_swap_markdecrypt(sdp, startslot, npages, encrypt); #endif s = splbio(); swapdev_vp->v_numoutput++; splx(s); } /* for async ops we must set up the iodone handler. */ if (async) { bp->b_flags |= B_CALL | (pdaemon ? B_PDAEMON : 0); bp->b_iodone = uvm_aio_biodone; } /* now we start the I/O, and if async, return. */ VOP_STRATEGY(bp->b_vp, bp); if (async) return (VM_PAGER_PEND); /* must be sync i/o. wait for it to finish */ (void) biowait(bp); result = (bp->b_flags & B_ERROR) ? VM_PAGER_ERROR : VM_PAGER_OK; /* decrypt swap */ if (!write && !(bp->b_flags & B_ERROR)) { int i; caddr_t data = (caddr_t)kva; caddr_t dst = (caddr_t)kva; u_int64_t block = startblk; if (bounce) data = (caddr_t)bouncekva; for (i = 0; i < npages; i++) { #ifdef UVM_SWAP_ENCRYPT struct swap_key *key; /* Check if we need to decrypt */ if (swap_encrypt_initialized && uvm_swap_needdecrypt(sdp, startslot + i)) { key = SWD_KEY(sdp, startslot + i); if (key->refcount == 0) { result = VM_PAGER_ERROR; break; } swap_decrypt(key, data, dst, block, PAGE_SIZE); } else if (bounce) { #else if (bounce) { #endif memcpy(dst, data, PAGE_SIZE); } data += PAGE_SIZE; dst += PAGE_SIZE; block += btodb(PAGE_SIZE); } if (bounce) uvm_pagermapout(bouncekva, npages); } /* kill the pager mapping */ uvm_pagermapout(kva, npages); /* Not anymore needed, free after encryption/bouncing */ if (!write && bounce) uvm_swap_freepages(tpps, npages); /* now dispose of the buf */ s = splbio(); if (bp->b_vp) brelvp(bp); if (write && bp->b_vp) vwakeup(bp->b_vp); pool_put(&bufpool, bp); splx(s); /* finally return. */ return (result); } void swapmount(void) { struct swapdev *sdp; struct swappri *spp; struct vnode *vp; dev_t swap_dev = swdevt[0].sw_dev; char *nam; char path[MNAMELEN + 1]; if (swap_dev == NODEV) return; rw_enter_write(&swap_syscall_lock); #if defined(NFSCLIENT) if (swap_dev == NETDEV) { extern struct nfs_diskless nfs_diskless; snprintf(path, sizeof(path), "%s", nfs_diskless.nd_swap.ndm_host); vp = nfs_diskless.sw_vp; goto gotit; } else #endif if (bdevvp(swap_dev, &vp)) return; /* Construct a potential path to swap */ if ((nam = findblkname(major(swap_dev)))) snprintf(path, sizeof(path), "/dev/%s%d%c", nam, DISKUNIT(swap_dev), 'a' + DISKPART(swap_dev)); else snprintf(path, sizeof(path), "blkdev0x%x", swap_dev); #if defined(NFSCLIENT) gotit: #endif sdp = malloc(sizeof(*sdp), M_VMSWAP, M_WAITOK|M_ZERO); spp = malloc(sizeof(*spp), M_VMSWAP, M_WAITOK); sdp->swd_flags = SWF_FAKE; sdp->swd_dev = swap_dev; sdp->swd_pathlen = strlen(path) + 1; sdp->swd_path = malloc(sdp->swd_pathlen, M_VMSWAP, M_WAITOK | M_ZERO); strlcpy(sdp->swd_path, path, sdp->swd_pathlen); sdp->swd_vp = vp; mtx_enter(&uvm_swap_data_lock); swaplist_insert(sdp, spp, 0); mtx_leave(&uvm_swap_data_lock); if (swap_on(curproc, sdp)) { mtx_enter(&uvm_swap_data_lock); swaplist_find(vp, 1); swaplist_trim(); vput(sdp->swd_vp); mtx_leave(&uvm_swap_data_lock); rw_exit_write(&swap_syscall_lock); free(sdp->swd_path, M_VMSWAP, sdp->swd_pathlen); free(sdp, M_VMSWAP, sizeof(*sdp)); return; } rw_exit_write(&swap_syscall_lock); } #ifdef HIBERNATE int uvm_hibswap(dev_t dev, u_long *sp, u_long *ep) { struct swapdev *sdp, *swd = NULL; struct swappri *spp; /* no swap devices configured yet? */ if (uvmexp.nswapdev < 1 || dev != swdevt[0].sw_dev) return (1); LIST_FOREACH(spp, &swap_priority, spi_swappri) { TAILQ_FOREACH(sdp, &spp->spi_swapdev, swd_next) { if (sdp->swd_dev == dev) swd = sdp; } } if (swd == NULL || (swd->swd_flags & SWF_ENABLE) == 0) return (1); blist_gapfind(swd->swd_blist, sp, ep); if (*ep - *sp == 0) /* no gap found */ return (1); /* * blist_gapfind returns the gap as [sp,ep[ , * whereas [sp,ep] is expected from uvm_hibswap(). */ *ep -= 1; return (0); } #endif /* HIBERNATE */ #ifdef DDB void swap_print_all(int (*pr)(const char *, ...)) { struct swappri *spp; struct swapdev *sdp; LIST_FOREACH(spp, &swap_priority, spi_swappri) { TAILQ_FOREACH(sdp, &spp->spi_swapdev, swd_next) { #ifdef HIBERNATE u_long bgap = 0, egap = 0; #endif pr("swap %p path \"%s\" flags 0x%x\n", sdp, sdp->swd_path, sdp->swd_flags); blist_print(sdp->swd_blist); #ifdef HIBERNATE if (!uvm_hibswap(sdp->swd_dev, &bgap, &egap)) pr("hibernate gap: [0x%lx, 0x%lx] size=%lu\n", bgap, egap, (egap - bgap + 1)); else pr("hibernate gap: not found\n"); #endif } } } #endif /* DDB */