/* --------------------------------------------------------------------- */
static int
tmpfs_nocacheread(vm_object_t tobj, vm_pindex_t idx,
vm_offset_t offset, size_t tlen, struct uio *uio)
{
vm_page_t m;
int error, rv;
VM_OBJECT_LOCK(tobj);
m = vm_page_grab(tobj, idx, VM_ALLOC_WIRED |
VM_ALLOC_NORMAL | VM_ALLOC_RETRY);
if (m->valid != VM_PAGE_BITS_ALL) {
if (vm_pager_has_page(tobj, idx, NULL, NULL)) {
rv = vm_pager_get_pages(tobj, &m, 1, 0);
if (rv != VM_PAGER_OK) {
vm_page_lock(m);
vm_page_free(m);
vm_page_unlock(m);
VM_OBJECT_UNLOCK(tobj);
return (EIO);
}
} else
vm_page_zero_invalid(m, TRUE);
}
VM_OBJECT_UNLOCK(tobj);
error = uiomove_fromphys(&m, offset, tlen, uio);
VM_OBJECT_LOCK(tobj);
vm_page_lock(m);
vm_page_unwire(m, TRUE);
vm_page_unlock(m);
vm_page_wakeup(m);
VM_OBJECT_UNLOCK(tobj);
return (error);
}
/* --------------------------------------------------------------------- */
static int
tmpfs_nocacheread(vm_object_t tobj, vm_pindex_t idx,
vm_offset_t offset, size_t tlen, struct uio *uio)
{
vm_page_t m;
int error;
VM_OBJECT_LOCK(tobj);
vm_object_pip_add(tobj, 1);
m = vm_page_grab(tobj, idx, VM_ALLOC_WIRED |
VM_ALLOC_ZERO | VM_ALLOC_NORMAL | VM_ALLOC_RETRY);
if (m->valid != VM_PAGE_BITS_ALL) {
if (vm_pager_has_page(tobj, idx, NULL, NULL)) {
error = vm_pager_get_pages(tobj, &m, 1, 0);
if (error != 0) {
printf("tmpfs get pages from pager error [read]\n");
goto out;
}
} else
vm_page_zero_invalid(m, TRUE);
}
VM_OBJECT_UNLOCK(tobj);
error = uiomove_fromphys(&m, offset, tlen, uio);
VM_OBJECT_LOCK(tobj);
out:
vm_page_lock(m);
vm_page_unwire(m, TRUE);
vm_page_unlock(m);
vm_page_wakeup(m);
vm_object_pip_subtract(tobj, 1);
VM_OBJECT_UNLOCK(tobj);
return (error);
}
/*
* This is the same as uiomove() except (cp, n) is within the bounds of
* the passed, locked buffer. Under certain circumstances a VM fault
* occuring with a locked buffer held can result in a deadlock or an
* attempt to recursively lock the buffer.
*
* This procedure deals with these cases.
*
* If the buffer represents a regular file, is B_CACHE, but the last VM page
* is not fully valid we fix-up the last VM page. This should handle the
* recursive lock issue.
*
* Deadlocks are another issue. We are holding the vp and the bp locked
* and could deadlock against a different vp and/or bp if another thread is
* trying to access us while we accessing it. The only solution here is
* to release the bp and vnode lock and do the uio to/from a system buffer,
* then regain the locks and copyback (if applicable). XXX TODO.
*/
int
uiomovebp(struct buf *bp, caddr_t cp, size_t n, struct uio *uio)
{
int count;
vm_page_t m;
if (bp->b_vp && bp->b_vp->v_type == VREG &&
(bp->b_flags & B_CACHE) &&
(count = bp->b_xio.xio_npages) != 0 &&
(m = bp->b_xio.xio_pages[count-1])->valid != VM_PAGE_BITS_ALL) {
vm_page_zero_invalid(m, TRUE);
}
return (uiomove(cp, n, uio));
}
int ttm_tt_swapin(struct ttm_tt *ttm)
{
vm_object_t obj;
vm_page_t from_page, to_page;
int i, ret, rv;
obj = ttm->swap_storage;
VM_OBJECT_LOCK(obj);
vm_object_pip_add(obj, 1);
for (i = 0; i < ttm->num_pages; ++i) {
from_page = vm_page_grab(obj, i, VM_ALLOC_NORMAL |
VM_ALLOC_RETRY);
if (from_page->valid != VM_PAGE_BITS_ALL) {
if (vm_pager_has_page(obj, i)) {
rv = vm_pager_get_page(obj, &from_page, 1);
if (rv != VM_PAGER_OK) {
vm_page_free(from_page);
ret = -EIO;
goto err_ret;
}
} else {
vm_page_zero_invalid(from_page, TRUE);
}
}
to_page = ttm->pages[i];
if (unlikely(to_page == NULL)) {
ret = -ENOMEM;
vm_page_wakeup(from_page);
goto err_ret;
}
pmap_copy_page(VM_PAGE_TO_PHYS(from_page),
VM_PAGE_TO_PHYS(to_page));
vm_page_wakeup(from_page);
}
vm_object_pip_wakeup(obj);
VM_OBJECT_UNLOCK(obj);
if (!(ttm->page_flags & TTM_PAGE_FLAG_PERSISTENT_SWAP))
vm_object_deallocate(obj);
ttm->swap_storage = NULL;
ttm->page_flags &= ~TTM_PAGE_FLAG_SWAPPED;
return (0);
err_ret:
vm_object_pip_wakeup(obj);
VM_OBJECT_UNLOCK(obj);
return (ret);
}
static int
tmpfs_mappedwrite(vm_object_t vobj, vm_object_t tobj, size_t len, struct uio *uio)
{
vm_pindex_t idx;
vm_page_t vpg, tpg;
vm_offset_t offset;
off_t addr;
size_t tlen;
int error, rv;
error = 0;
addr = uio->uio_offset;
idx = OFF_TO_IDX(addr);
offset = addr & PAGE_MASK;
tlen = MIN(PAGE_SIZE - offset, len);
if ((vobj == NULL) ||
(vobj->resident_page_count == 0 && vobj->cache == NULL)) {
vpg = NULL;
goto nocache;
}
VM_OBJECT_LOCK(vobj);
lookupvpg:
if (((vpg = vm_page_lookup(vobj, idx)) != NULL) &&
vm_page_is_valid(vpg, offset, tlen)) {
if ((vpg->oflags & VPO_BUSY) != 0) {
/*
* Reference the page before unlocking and sleeping so
* that the page daemon is less likely to reclaim it.
*/
vm_page_reference(vpg);
vm_page_sleep(vpg, "tmfsmw");
goto lookupvpg;
}
vm_page_busy(vpg);
vm_page_undirty(vpg);
VM_OBJECT_UNLOCK(vobj);
error = uiomove_fromphys(&vpg, offset, tlen, uio);
} else {
if (__predict_false(vobj->cache != NULL))
vm_page_cache_free(vobj, idx, idx + 1);
VM_OBJECT_UNLOCK(vobj);
vpg = NULL;
}
nocache:
VM_OBJECT_LOCK(tobj);
tpg = vm_page_grab(tobj, idx, VM_ALLOC_WIRED |
VM_ALLOC_NORMAL | VM_ALLOC_RETRY);
if (tpg->valid != VM_PAGE_BITS_ALL) {
if (vm_pager_has_page(tobj, idx, NULL, NULL)) {
rv = vm_pager_get_pages(tobj, &tpg, 1, 0);
if (rv != VM_PAGER_OK) {
vm_page_lock(tpg);
vm_page_free(tpg);
vm_page_unlock(tpg);
error = EIO;
goto out;
}
} else
vm_page_zero_invalid(tpg, TRUE);
}
VM_OBJECT_UNLOCK(tobj);
if (vpg == NULL)
error = uiomove_fromphys(&tpg, offset, tlen, uio);
else {
KASSERT(vpg->valid == VM_PAGE_BITS_ALL, ("parts of vpg invalid"));
pmap_copy_page(vpg, tpg);
}
VM_OBJECT_LOCK(tobj);
if (error == 0) {
KASSERT(tpg->valid == VM_PAGE_BITS_ALL,
("parts of tpg invalid"));
vm_page_dirty(tpg);
}
vm_page_lock(tpg);
vm_page_unwire(tpg, TRUE);
vm_page_unlock(tpg);
vm_page_wakeup(tpg);
out:
VM_OBJECT_UNLOCK(tobj);
if (vpg != NULL) {
VM_OBJECT_LOCK(vobj);
vm_page_wakeup(vpg);
VM_OBJECT_UNLOCK(vobj);
}
return (error);
}
static int
uiomove_object_page(vm_object_t obj, size_t len, struct uio *uio)
{
vm_page_t m;
vm_pindex_t idx;
size_t tlen;
int error, offset, rv;
idx = OFF_TO_IDX(uio->uio_offset);
offset = uio->uio_offset & PAGE_MASK;
tlen = MIN(PAGE_SIZE - offset, len);
VM_OBJECT_WLOCK(obj);
/*
* Parallel reads of the page content from disk are prevented
* by exclusive busy.
*
* Although the tmpfs vnode lock is held here, it is
* nonetheless safe to sleep waiting for a free page. The
* pageout daemon does not need to acquire the tmpfs vnode
* lock to page out tobj's pages because tobj is a OBJT_SWAP
* type object.
*/
m = vm_page_grab(obj, idx, VM_ALLOC_NORMAL);
if (m->valid != VM_PAGE_BITS_ALL) {
if (vm_pager_has_page(obj, idx, NULL, NULL)) {
rv = vm_pager_get_pages(obj, &m, 1, 0);
m = vm_page_lookup(obj, idx);
if (m == NULL) {
printf(
"uiomove_object: vm_obj %p idx %jd null lookup rv %d\n",
obj, idx, rv);
VM_OBJECT_WUNLOCK(obj);
return (EIO);
}
if (rv != VM_PAGER_OK) {
printf(
"uiomove_object: vm_obj %p idx %jd valid %x pager error %d\n",
obj, idx, m->valid, rv);
vm_page_lock(m);
vm_page_free(m);
vm_page_unlock(m);
VM_OBJECT_WUNLOCK(obj);
return (EIO);
}
} else
vm_page_zero_invalid(m, TRUE);
}
vm_page_xunbusy(m);
vm_page_lock(m);
vm_page_hold(m);
vm_page_unlock(m);
VM_OBJECT_WUNLOCK(obj);
error = uiomove_fromphys(&m, offset, tlen, uio);
if (uio->uio_rw == UIO_WRITE && error == 0) {
VM_OBJECT_WLOCK(obj);
vm_page_dirty(m);
VM_OBJECT_WUNLOCK(obj);
}
vm_page_lock(m);
vm_page_unhold(m);
if (m->queue == PQ_NONE) {
vm_page_deactivate(m);
} else {
/* Requeue to maintain LRU ordering. */
vm_page_requeue(m);
}
vm_page_unlock(m);
return (error);
}
/*
* This is now called from local media FS's to operate against their
* own vnodes if they fail to implement VOP_GETPAGES.
*
* With all the caching local media devices do these days there is really
* very little point to attempting to restrict the I/O size to contiguous
* blocks on-disk, especially if our caller thinks we need all the specified
* pages. Just construct and issue a READ.
*/
int
vnode_pager_generic_getpages(struct vnode *vp, vm_page_t *mpp, int bytecount,
int reqpage, int seqaccess)
{
struct iovec aiov;
struct uio auio;
off_t foff;
int error;
int count;
int i;
int ioflags;
/*
* Do not do anything if the vnode is bad.
*/
if (vp->v_mount == NULL)
return VM_PAGER_BAD;
/*
* Calculate the number of pages. Since we are paging in whole
* pages, adjust bytecount to be an integral multiple of the page
* size. It will be clipped to the file EOF later on.
*/
bytecount = round_page(bytecount);
count = bytecount / PAGE_SIZE;
/*
* We could check m[reqpage]->valid here and shortcut the operation,
* but doing so breaks read-ahead. Instead assume that the VM
* system has already done at least the check, don't worry about
* any races, and issue the VOP_READ to allow read-ahead to function.
*
* This keeps the pipeline full for I/O bound sequentially scanned
* mmap()'s
*/
/* don't shortcut */
/*
* Discard pages past the file EOF. If the requested page is past
* the file EOF we just leave its valid bits set to 0, the caller
* expects to maintain ownership of the requested page. If the
* entire range is past file EOF discard everything and generate
* a pagein error.
*/
foff = IDX_TO_OFF(mpp[0]->pindex);
if (foff >= vp->v_filesize) {
for (i = 0; i < count; i++) {
if (i != reqpage)
vnode_pager_freepage(mpp[i]);
}
return VM_PAGER_ERROR;
}
if (foff + bytecount > vp->v_filesize) {
bytecount = vp->v_filesize - foff;
i = round_page(bytecount) / PAGE_SIZE;
while (count > i) {
--count;
if (count != reqpage)
vnode_pager_freepage(mpp[count]);
}
}
/*
* The size of the transfer is bytecount. bytecount will be an
* integral multiple of the page size unless it has been clipped
* to the file EOF. The transfer cannot exceed the file EOF.
*
* When dealing with real devices we must round-up to the device
* sector size.
*/
if (vp->v_type == VBLK || vp->v_type == VCHR) {
int secmask = vp->v_rdev->si_bsize_phys - 1;
KASSERT(secmask < PAGE_SIZE, ("vnode_pager_generic_getpages: sector size %d too large", secmask + 1));
bytecount = (bytecount + secmask) & ~secmask;
}
/*
* Severe hack to avoid deadlocks with the buffer cache
*/
for (i = 0; i < count; ++i) {
vm_page_t mt = mpp[i];
vm_page_io_start(mt);
vm_page_wakeup(mt);
}
/*
* Issue the I/O with some read-ahead if bytecount > PAGE_SIZE
*/
ioflags = IO_VMIO;
if (seqaccess)
ioflags |= IO_SEQMAX << IO_SEQSHIFT;
aiov.iov_base = NULL;
aiov.iov_len = bytecount;
auio.uio_iov = &aiov;
auio.uio_iovcnt = 1;
auio.uio_offset = foff;
auio.uio_segflg = UIO_NOCOPY;
auio.uio_rw = UIO_READ;
auio.uio_resid = bytecount;
auio.uio_td = NULL;
mycpu->gd_cnt.v_vnodein++;
mycpu->gd_cnt.v_vnodepgsin += count;
error = VOP_READ(vp, &auio, ioflags, proc0.p_ucred);
/*
* Severe hack to avoid deadlocks with the buffer cache
*/
for (i = 0; i < count; ++i) {
vm_page_busy_wait(mpp[i], FALSE, "getpgs");
vm_page_io_finish(mpp[i]);
}
/*
* Calculate the actual number of bytes read and clean up the
* page list.
*/
bytecount -= auio.uio_resid;
for (i = 0; i < count; ++i) {
vm_page_t mt = mpp[i];
if (i != reqpage) {
if (error == 0 && mt->valid) {
if (mt->flags & PG_REFERENCED)
vm_page_activate(mt);
else
vm_page_deactivate(mt);
vm_page_wakeup(mt);
} else {
vnode_pager_freepage(mt);
}
} else if (mt->valid == 0) {
if (error == 0) {
kprintf("page failed but no I/O error page "
"%p object %p pindex %d\n",
mt, mt->object, (int) mt->pindex);
/* whoops, something happened */
error = EINVAL;
}
} else if (mt->valid != VM_PAGE_BITS_ALL) {
/*
* Zero-extend the requested page if necessary (if
* the filesystem is using a small block size).
*/
vm_page_zero_invalid(mt, TRUE);
}
}
if (error) {
kprintf("vnode_pager_getpage: I/O read error\n");
}
return (error ? VM_PAGER_ERROR : VM_PAGER_OK);
}
/*
* spec_getpages() - get pages associated with device vnode.
*
* Note that spec_read and spec_write do not use the buffer cache, so we
* must fully implement getpages here.
*/
static int
devfs_spec_getpages(struct vop_getpages_args *ap)
{
vm_offset_t kva;
int error;
int i, pcount, size;
struct buf *bp;
vm_page_t m;
vm_ooffset_t offset;
int toff, nextoff, nread;
struct vnode *vp = ap->a_vp;
int blksiz;
int gotreqpage;
error = 0;
pcount = round_page(ap->a_count) / PAGE_SIZE;
/*
* Calculate the offset of the transfer and do sanity check.
*/
offset = IDX_TO_OFF(ap->a_m[0]->pindex) + ap->a_offset;
/*
* Round up physical size for real devices. We cannot round using
* v_mount's block size data because v_mount has nothing to do with
* the device. i.e. it's usually '/dev'. We need the physical block
* size for the device itself.
*
* We can't use v_rdev->si_mountpoint because it only exists when the
* block device is mounted. However, we can use v_rdev.
*/
if (vn_isdisk(vp, NULL))
blksiz = vp->v_rdev->si_bsize_phys;
else
blksiz = DEV_BSIZE;
size = (ap->a_count + blksiz - 1) & ~(blksiz - 1);
bp = getpbuf_kva(NULL);
kva = (vm_offset_t)bp->b_data;
/*
* Map the pages to be read into the kva.
*/
pmap_qenter(kva, ap->a_m, pcount);
/* Build a minimal buffer header. */
bp->b_cmd = BUF_CMD_READ;
bp->b_bcount = size;
bp->b_resid = 0;
bsetrunningbufspace(bp, size);
bp->b_bio1.bio_offset = offset;
bp->b_bio1.bio_done = devfs_spec_getpages_iodone;
mycpu->gd_cnt.v_vnodein++;
mycpu->gd_cnt.v_vnodepgsin += pcount;
/* Do the input. */
vn_strategy(ap->a_vp, &bp->b_bio1);
crit_enter();
/* We definitely need to be at splbio here. */
while (bp->b_cmd != BUF_CMD_DONE)
tsleep(bp, 0, "spread", 0);
crit_exit();
if (bp->b_flags & B_ERROR) {
if (bp->b_error)
error = bp->b_error;
else
error = EIO;
}
/*
* If EOF is encountered we must zero-extend the result in order
* to ensure that the page does not contain garabge. When no
* error occurs, an early EOF is indicated if b_bcount got truncated.
* b_resid is relative to b_bcount and should be 0, but some devices
* might indicate an EOF with b_resid instead of truncating b_bcount.
*/
nread = bp->b_bcount - bp->b_resid;
if (nread < ap->a_count)
bzero((caddr_t)kva + nread, ap->a_count - nread);
pmap_qremove(kva, pcount);
gotreqpage = 0;
for (i = 0, toff = 0; i < pcount; i++, toff = nextoff) {
nextoff = toff + PAGE_SIZE;
m = ap->a_m[i];
m->flags &= ~PG_ZERO;
/*
* NOTE: vm_page_undirty/clear_dirty etc do not clear the
* pmap modified bit. pmap modified bit should have
* already been cleared.
*/
if (nextoff <= nread) {
m->valid = VM_PAGE_BITS_ALL;
vm_page_undirty(m);
} else if (toff < nread) {
/*
* Since this is a VM request, we have to supply the
* unaligned offset to allow vm_page_set_valid()
* to zero sub-DEV_BSIZE'd portions of the page.
*/
vm_page_set_valid(m, 0, nread - toff);
vm_page_clear_dirty_end_nonincl(m, 0, nread - toff);
} else {
m->valid = 0;
vm_page_undirty(m);
}
if (i != ap->a_reqpage) {
/*
* Just in case someone was asking for this page we
* now tell them that it is ok to use.
*/
if (!error || (m->valid == VM_PAGE_BITS_ALL)) {
if (m->valid) {
if (m->flags & PG_REFERENCED) {
vm_page_activate(m);
} else {
vm_page_deactivate(m);
}
vm_page_wakeup(m);
} else {
vm_page_free(m);
}
} else {
vm_page_free(m);
}
} else if (m->valid) {
gotreqpage = 1;
/*
* Since this is a VM request, we need to make the
* entire page presentable by zeroing invalid sections.
*/
if (m->valid != VM_PAGE_BITS_ALL)
vm_page_zero_invalid(m, FALSE);
}
}
if (!gotreqpage) {
m = ap->a_m[ap->a_reqpage];
devfs_debug(DEVFS_DEBUG_WARNING,
"spec_getpages:(%s) I/O read failure: (error=%d) bp %p vp %p\n",
devtoname(vp->v_rdev), error, bp, bp->b_vp);
devfs_debug(DEVFS_DEBUG_WARNING,
" size: %d, resid: %d, a_count: %d, valid: 0x%x\n",
size, bp->b_resid, ap->a_count, m->valid);
devfs_debug(DEVFS_DEBUG_WARNING,
" nread: %d, reqpage: %d, pindex: %lu, pcount: %d\n",
nread, ap->a_reqpage, (u_long)m->pindex, pcount);
/*
* Free the buffer header back to the swap buffer pool.
*/
relpbuf(bp, NULL);
return VM_PAGER_ERROR;
}
/*
* Free the buffer header back to the swap buffer pool.
*/
relpbuf(bp, NULL);
if (DEVFS_NODE(ap->a_vp))
nanotime(&DEVFS_NODE(ap->a_vp)->mtime);
return VM_PAGER_OK;
}
