static int
ulz_put(struct uvm_object *uobj, voff_t start, voff_t stop, int flags)
{
struct vm_page *pg;
KDASSERT(uobj == &uvm_loanzero_object);
/*
* Don't need to do any work here if we're not freeing pages.
*/
if ((flags & PGO_FREE) == 0) {
mutex_exit(&uobj->vmobjlock);
return 0;
}
/*
* we don't actually want to ever free the uvm_loanzero_page, so
* just reactivate or dequeue it.
*/
pg = TAILQ_FIRST(&uobj->memq);
KASSERT(pg != NULL);
KASSERT(TAILQ_NEXT(pg, listq.queue) == NULL);
mutex_enter(&uvm_pageqlock);
if (pg->uanon)
uvm_pageactivate(pg);
else
uvm_pagedequeue(pg);
mutex_exit(&uvm_pageqlock);
mutex_exit(&uobj->vmobjlock);
return 0;
}
int
uvm_loanbreak_anon(struct vm_anon *anon, struct uvm_object *uobj)
{
struct vm_page *pg;
KASSERT(mutex_owned(anon->an_lock));
KASSERT(uobj == NULL || mutex_owned(uobj->vmobjlock));
/* get new un-owned replacement page */
pg = uvm_pagealloc(NULL, 0, NULL, 0);
if (pg == NULL) {
return ENOMEM;
}
/* copy old -> new */
uvm_pagecopy(anon->an_page, pg);
/* force reload */
pmap_page_protect(anon->an_page, VM_PROT_NONE);
mutex_enter(&uvm_pageqlock); /* KILL loan */
anon->an_page->uanon = NULL;
/* in case we owned */
anon->an_page->pqflags &= ~PQ_ANON;
if (uobj) {
/* if we were receiver of loan */
anon->an_page->loan_count--;
} else {
/*
* we were the lender (A->K); need to remove the page from
* pageq's.
*/
uvm_pagedequeue(anon->an_page);
}
if (uobj) {
mutex_exit(uobj->vmobjlock);
}
/* install new page in anon */
anon->an_page = pg;
pg->uanon = anon;
pg->pqflags |= PQ_ANON;
uvm_pageactivate(pg);
mutex_exit(&uvm_pageqlock);
pg->flags &= ~(PG_BUSY|PG_FAKE);
UVM_PAGE_OWN(pg, NULL);
/* done! */
return 0;
}
/*
* uvm_loanpage: loan out pages to kernel (->K)
*
* => pages should be object-owned and the object should be locked.
* => in the case of error, the object might be unlocked and relocked.
* => caller should busy the pages beforehand.
* => pages will be unbusied.
* => fail with EBUSY if meet a wired page.
*/
static int
uvm_loanpage(struct vm_page **pgpp, int npages)
{
int i;
int error = 0;
UVMHIST_FUNC(__func__); UVMHIST_CALLED(loanhist);
for (i = 0; i < npages; i++) {
struct vm_page *pg = pgpp[i];
KASSERT(pg->uobject != NULL);
KASSERT(pg->uobject == pgpp[0]->uobject);
KASSERT(!(pg->flags & (PG_RELEASED|PG_PAGEOUT)));
KASSERT(mutex_owned(&pg->uobject->vmobjlock));
KASSERT(pg->flags & PG_BUSY);
mutex_enter(&uvm_pageqlock);
if (pg->wire_count > 0) {
mutex_exit(&uvm_pageqlock);
UVMHIST_LOG(loanhist, "wired %p", pg,0,0,0);
error = EBUSY;
break;
}
if (pg->loan_count == 0) {
pmap_page_protect(pg, VM_PROT_READ);
}
pg->loan_count++;
uvm_pageactivate(pg);
mutex_exit(&uvm_pageqlock);
}
uvm_page_unbusy(pgpp, npages);
if (error) {
/*
* backout what we've done
*/
kmutex_t *slock = &pgpp[0]->uobject->vmobjlock;
mutex_exit(slock);
uvm_unloan(pgpp, i, UVM_LOAN_TOPAGE);
mutex_enter(slock);
}
UVMHIST_LOG(loanhist, "done %d", error,0,0,0);
return error;
}
static int
uvm_loanzero(struct uvm_faultinfo *ufi, void ***output, int flags)
{
struct vm_anon *anon;
struct vm_page *pg;
struct vm_amap *amap = ufi->entry->aref.ar_amap;
UVMHIST_FUNC(__func__); UVMHIST_CALLED(loanhist);
again:
mutex_enter(&uvm_loanzero_object.vmobjlock);
/*
* first, get ahold of our single zero page.
*/
if (__predict_false((pg =
TAILQ_FIRST(&uvm_loanzero_object.memq)) == NULL)) {
while ((pg = uvm_pagealloc(&uvm_loanzero_object, 0, NULL,
UVM_PGA_ZERO)) == NULL) {
mutex_exit(&uvm_loanzero_object.vmobjlock);
uvmfault_unlockall(ufi, amap, NULL, NULL);
uvm_wait("loanzero");
if (!uvmfault_relock(ufi)) {
return (0);
}
if (amap) {
amap_lock(amap);
}
goto again;
}
/* got a zero'd page. */
pg->flags &= ~(PG_WANTED|PG_BUSY|PG_FAKE);
pg->flags |= PG_RDONLY;
mutex_enter(&uvm_pageqlock);
uvm_pageactivate(pg);
mutex_exit(&uvm_pageqlock);
UVM_PAGE_OWN(pg, NULL);
}
if ((flags & UVM_LOAN_TOANON) == 0) { /* loaning to kernel-page */
mutex_enter(&uvm_pageqlock);
pg->loan_count++;
mutex_exit(&uvm_pageqlock);
mutex_exit(&uvm_loanzero_object.vmobjlock);
**output = pg;
(*output)++;
return (1);
}
/*
* loaning to an anon. check to see if there is already an anon
* associated with this page. if so, then just return a reference
* to this object.
*/
if (pg->uanon) {
anon = pg->uanon;
mutex_enter(&anon->an_lock);
anon->an_ref++;
mutex_exit(&anon->an_lock);
mutex_exit(&uvm_loanzero_object.vmobjlock);
**output = anon;
(*output)++;
return (1);
}
/*
* need to allocate a new anon
*/
anon = uvm_analloc();
if (anon == NULL) {
/* out of swap causes us to fail */
mutex_exit(&uvm_loanzero_object.vmobjlock);
uvmfault_unlockall(ufi, amap, NULL, NULL);
return (-1);
}
anon->an_page = pg;
pg->uanon = anon;
mutex_enter(&uvm_pageqlock);
pg->loan_count++;
uvm_pageactivate(pg);
mutex_exit(&uvm_pageqlock);
mutex_exit(&anon->an_lock);
mutex_exit(&uvm_loanzero_object.vmobjlock);
**output = anon;
(*output)++;
return (1);
}
static int
uvm_loanuobj(struct uvm_faultinfo *ufi, void ***output, int flags, vaddr_t va)
{
struct vm_amap *amap = ufi->entry->aref.ar_amap;
struct uvm_object *uobj = ufi->entry->object.uvm_obj;
struct vm_page *pg;
struct vm_anon *anon;
int error, npages;
bool locked;
UVMHIST_FUNC(__func__); UVMHIST_CALLED(loanhist);
/*
* first we must make sure the page is resident.
*
* XXXCDC: duplicate code with uvm_fault().
*/
mutex_enter(&uobj->vmobjlock);
if (uobj->pgops->pgo_get) { /* try locked pgo_get */
npages = 1;
pg = NULL;
error = (*uobj->pgops->pgo_get)(uobj,
va - ufi->entry->start + ufi->entry->offset,
&pg, &npages, 0, VM_PROT_READ, MADV_NORMAL, PGO_LOCKED);
} else {
error = EIO; /* must have pgo_get op */
}
/*
* check the result of the locked pgo_get. if there is a problem,
* then we fail the loan.
*/
if (error && error != EBUSY) {
uvmfault_unlockall(ufi, amap, uobj, NULL);
return (-1);
}
/*
* if we need to unlock for I/O, do so now.
*/
if (error == EBUSY) {
uvmfault_unlockall(ufi, amap, NULL, NULL);
/* locked: uobj */
npages = 1;
error = (*uobj->pgops->pgo_get)(uobj,
va - ufi->entry->start + ufi->entry->offset,
&pg, &npages, 0, VM_PROT_READ, MADV_NORMAL, PGO_SYNCIO);
/* locked: <nothing> */
if (error) {
if (error == EAGAIN) {
tsleep(&lbolt, PVM, "fltagain2", 0);
return (0);
}
return (-1);
}
/*
* pgo_get was a success. attempt to relock everything.
*/
locked = uvmfault_relock(ufi);
if (locked && amap)
amap_lock(amap);
uobj = pg->uobject;
mutex_enter(&uobj->vmobjlock);
/*
* verify that the page has not be released and re-verify
* that amap slot is still free. if there is a problem we
* drop our lock (thus force a lookup refresh/retry).
*/
if ((pg->flags & PG_RELEASED) != 0 ||
(locked && amap && amap_lookup(&ufi->entry->aref,
ufi->orig_rvaddr - ufi->entry->start))) {
if (locked)
uvmfault_unlockall(ufi, amap, NULL, NULL);
locked = false;
}
/*
* didn't get the lock? release the page and retry.
*/
if (locked == false) {
if (pg->flags & PG_WANTED) {
wakeup(pg);
}
if (pg->flags & PG_RELEASED) {
mutex_enter(&uvm_pageqlock);
uvm_pagefree(pg);
mutex_exit(&uvm_pageqlock);
mutex_exit(&uobj->vmobjlock);
return (0);
}
mutex_enter(&uvm_pageqlock);
uvm_pageactivate(pg);
mutex_exit(&uvm_pageqlock);
pg->flags &= ~(PG_BUSY|PG_WANTED);
UVM_PAGE_OWN(pg, NULL);
mutex_exit(&uobj->vmobjlock);
return (0);
}
}
KASSERT(uobj == pg->uobject);
/*
* at this point we have the page we want ("pg") marked PG_BUSY for us
* and we have all data structures locked. do the loanout. page can
* not be PG_RELEASED (we caught this above).
*/
if ((flags & UVM_LOAN_TOANON) == 0) {
if (uvm_loanpage(&pg, 1)) {
uvmfault_unlockall(ufi, amap, uobj, NULL);
return (-1);
}
mutex_exit(&uobj->vmobjlock);
**output = pg;
(*output)++;
return (1);
}
/*
* must be a loan to an anon. check to see if there is already
* an anon associated with this page. if so, then just return
* a reference to this object. the page should already be
* mapped read-only because it is already on loan.
*/
if (pg->uanon) {
anon = pg->uanon;
mutex_enter(&anon->an_lock);
anon->an_ref++;
mutex_exit(&anon->an_lock);
if (pg->flags & PG_WANTED) {
wakeup(pg);
}
pg->flags &= ~(PG_WANTED|PG_BUSY);
UVM_PAGE_OWN(pg, NULL);
mutex_exit(&uobj->vmobjlock);
**output = anon;
(*output)++;
return (1);
}
/*
* need to allocate a new anon
*/
anon = uvm_analloc();
if (anon == NULL) {
goto fail;
}
anon->an_page = pg;
pg->uanon = anon;
mutex_enter(&uvm_pageqlock);
if (pg->wire_count > 0) {
mutex_exit(&uvm_pageqlock);
UVMHIST_LOG(loanhist, "wired %p", pg,0,0,0);
pg->uanon = NULL;
anon->an_page = NULL;
anon->an_ref--;
mutex_exit(&anon->an_lock);
uvm_anfree(anon);
goto fail;
}
if (pg->loan_count == 0) {
pmap_page_protect(pg, VM_PROT_READ);
}
pg->loan_count++;
uvm_pageactivate(pg);
mutex_exit(&uvm_pageqlock);
if (pg->flags & PG_WANTED) {
wakeup(pg);
}
pg->flags &= ~(PG_WANTED|PG_BUSY);
UVM_PAGE_OWN(pg, NULL);
mutex_exit(&uobj->vmobjlock);
mutex_exit(&anon->an_lock);
**output = anon;
(*output)++;
return (1);
fail:
UVMHIST_LOG(loanhist, "fail", 0,0,0,0);
/*
* unlock everything and bail out.
*/
if (pg->flags & PG_WANTED) {
wakeup(pg);
}
pg->flags &= ~(PG_WANTED|PG_BUSY);
UVM_PAGE_OWN(pg, NULL);
uvmfault_unlockall(ufi, amap, uobj, NULL);
return (-1);
}
int
uvm_loananon(struct uvm_faultinfo *ufi, void ***output, int flags,
struct vm_anon *anon)
{
struct vm_page *pg;
int error;
UVMHIST_FUNC(__func__); UVMHIST_CALLED(loanhist);
/*
* if we are loaning to "another" anon then it is easy, we just
* bump the reference count on the current anon and return a
* pointer to it (it becomes copy-on-write shared).
*/
if (flags & UVM_LOAN_TOANON) {
mutex_enter(&anon->an_lock);
pg = anon->an_page;
if (pg && (pg->pqflags & PQ_ANON) != 0 && anon->an_ref == 1) {
if (pg->wire_count > 0) {
UVMHIST_LOG(loanhist, "->A wired %p", pg,0,0,0);
uvmfault_unlockall(ufi,
ufi->entry->aref.ar_amap,
ufi->entry->object.uvm_obj, anon);
return (-1);
}
pmap_page_protect(pg, VM_PROT_READ);
}
anon->an_ref++;
**output = anon;
(*output)++;
mutex_exit(&anon->an_lock);
UVMHIST_LOG(loanhist, "->A done", 0,0,0,0);
return (1);
}
/*
* we are loaning to a kernel-page. we need to get the page
* resident so we can wire it. uvmfault_anonget will handle
* this for us.
*/
mutex_enter(&anon->an_lock);
error = uvmfault_anonget(ufi, ufi->entry->aref.ar_amap, anon);
/*
* if we were unable to get the anon, then uvmfault_anonget has
* unlocked everything and returned an error code.
*/
if (error) {
UVMHIST_LOG(loanhist, "error %d", error,0,0,0);
/* need to refault (i.e. refresh our lookup) ? */
if (error == ERESTART) {
return (0);
}
/* "try again"? sleep a bit and retry ... */
if (error == EAGAIN) {
tsleep(&lbolt, PVM, "loanagain", 0);
return (0);
}
/* otherwise flag it as an error */
return (-1);
}
/*
* we have the page and its owner locked: do the loan now.
*/
pg = anon->an_page;
mutex_enter(&uvm_pageqlock);
if (pg->wire_count > 0) {
mutex_exit(&uvm_pageqlock);
UVMHIST_LOG(loanhist, "->K wired %p", pg,0,0,0);
KASSERT(pg->uobject == NULL);
uvmfault_unlockall(ufi, ufi->entry->aref.ar_amap,
NULL, anon);
return (-1);
}
if (pg->loan_count == 0) {
pmap_page_protect(pg, VM_PROT_READ);
}
pg->loan_count++;
uvm_pageactivate(pg);
mutex_exit(&uvm_pageqlock);
**output = pg;
(*output)++;
/* unlock anon and return success */
if (pg->uobject)
mutex_exit(&pg->uobject->vmobjlock);
mutex_exit(&anon->an_lock);
UVMHIST_LOG(loanhist, "->K done", 0,0,0,0);
return (1);
}
/*
* uvm_loanbreak: break loan on a uobj page
*
* => called with uobj locked
* => the page should be busy
* => return value:
* newly allocated page if succeeded
*/
struct vm_page *
uvm_loanbreak(struct vm_page *uobjpage)
{
struct vm_page *pg;
#ifdef DIAGNOSTIC
struct uvm_object *uobj = uobjpage->uobject;
#endif
KASSERT(uobj != NULL);
KASSERT(mutex_owned(&uobj->vmobjlock));
KASSERT(uobjpage->flags & PG_BUSY);
/* alloc new un-owned page */
pg = uvm_pagealloc(NULL, 0, NULL, 0);
if (pg == NULL)
return NULL;
/*
* copy the data from the old page to the new
* one and clear the fake flags on the new page (keep it busy).
* force a reload of the old page by clearing it from all
* pmaps.
* transfer dirtiness of the old page to the new page.
* then lock the page queues to rename the pages.
*/
uvm_pagecopy(uobjpage, pg); /* old -> new */
pg->flags &= ~PG_FAKE;
pmap_page_protect(uobjpage, VM_PROT_NONE);
if ((uobjpage->flags & PG_CLEAN) != 0 && !pmap_clear_modify(uobjpage)) {
pmap_clear_modify(pg);
pg->flags |= PG_CLEAN;
} else {
/* uvm_pagecopy marked it dirty */
KASSERT((pg->flags & PG_CLEAN) == 0);
/* a object with a dirty page should be dirty. */
KASSERT(!UVM_OBJ_IS_CLEAN(uobj));
}
if (uobjpage->flags & PG_WANTED)
wakeup(uobjpage);
/* uobj still locked */
uobjpage->flags &= ~(PG_WANTED|PG_BUSY);
UVM_PAGE_OWN(uobjpage, NULL);
mutex_enter(&uvm_pageqlock);
/*
* replace uobjpage with new page.
*/
uvm_pagereplace(uobjpage, pg);
/*
* if the page is no longer referenced by
* an anon (i.e. we are breaking an O->K
* loan), then remove it from any pageq's.
*/
if (uobjpage->uanon == NULL)
uvm_pagedequeue(uobjpage);
/*
* at this point we have absolutely no
* control over uobjpage
*/
/* install new page */
uvm_pageactivate(pg);
mutex_exit(&uvm_pageqlock);
/*
* done! loan is broken and "pg" is
* PG_BUSY. it can now replace uobjpage.
*/
return pg;
}
int
uvmfault_anonget(struct uvm_faultinfo *ufi, struct vm_amap *amap,
struct vm_anon *anon)
{
boolean_t we_own; /* we own anon's page? */
boolean_t locked; /* did we relock? */
struct vm_page *pg;
int result;
result = 0; /* XXX shut up gcc */
uvmexp.fltanget++;
/* bump rusage counters */
if (anon->an_page)
curproc->p_ru.ru_minflt++;
else
curproc->p_ru.ru_majflt++;
/*
* loop until we get it, or fail.
*/
while (1) {
we_own = FALSE; /* TRUE if we set PG_BUSY on a page */
pg = anon->an_page;
/*
* if there is a resident page and it is loaned, then anon
* may not own it. call out to uvm_anon_lockpage() to ensure
* the real owner of the page has been identified and locked.
*/
if (pg && pg->loan_count)
pg = uvm_anon_lockloanpg(anon);
/*
* page there? make sure it is not busy/released.
*/
if (pg) {
/*
* at this point, if the page has a uobject [meaning
* we have it on loan], then that uobject is locked
* by us! if the page is busy, we drop all the
* locks (including uobject) and try again.
*/
if ((pg->pg_flags & (PG_BUSY|PG_RELEASED)) == 0) {
return (VM_PAGER_OK);
}
atomic_setbits_int(&pg->pg_flags, PG_WANTED);
uvmexp.fltpgwait++;
/*
* the last unlock must be an atomic unlock+wait on
* the owner of page
*/
if (pg->uobject) { /* owner is uobject ? */
uvmfault_unlockall(ufi, amap, NULL, anon);
UVM_UNLOCK_AND_WAIT(pg,
&pg->uobject->vmobjlock,
FALSE, "anonget1",0);
} else {
/* anon owns page */
uvmfault_unlockall(ufi, amap, NULL, NULL);
UVM_UNLOCK_AND_WAIT(pg,&anon->an_lock,0,
"anonget2",0);
}
/* ready to relock and try again */
} else {
/*
* no page, we must try and bring it in.
*/
pg = uvm_pagealloc(NULL, 0, anon, 0);
if (pg == NULL) { /* out of RAM. */
uvmfault_unlockall(ufi, amap, NULL, anon);
uvmexp.fltnoram++;
uvm_wait("flt_noram1");
/* ready to relock and try again */
} else {
/* we set the PG_BUSY bit */
we_own = TRUE;
uvmfault_unlockall(ufi, amap, NULL, anon);
/*
* we are passing a PG_BUSY+PG_FAKE+PG_CLEAN
* page into the uvm_swap_get function with
* all data structures unlocked. note that
* it is ok to read an_swslot here because
* we hold PG_BUSY on the page.
*/
uvmexp.pageins++;
result = uvm_swap_get(pg, anon->an_swslot,
PGO_SYNCIO);
/*
* we clean up after the i/o below in the
* "we_own" case
*/
/* ready to relock and try again */
}
}
/*
* now relock and try again
*/
locked = uvmfault_relock(ufi);
if (locked || we_own)
simple_lock(&anon->an_lock);
/*
* if we own the page (i.e. we set PG_BUSY), then we need
* to clean up after the I/O. there are three cases to
* consider:
* [1] page released during I/O: free anon and ReFault.
* [2] I/O not OK. free the page and cause the fault
* to fail.
* [3] I/O OK! activate the page and sync with the
* non-we_own case (i.e. drop anon lock if not locked).
*/
if (we_own) {
if (pg->pg_flags & PG_WANTED) {
/* still holding object lock */
wakeup(pg);
}
/* un-busy! */
atomic_clearbits_int(&pg->pg_flags,
PG_WANTED|PG_BUSY|PG_FAKE);
UVM_PAGE_OWN(pg, NULL);
/*
* if we were RELEASED during I/O, then our anon is
* no longer part of an amap. we need to free the
* anon and try again.
*/
if (pg->pg_flags & PG_RELEASED) {
pmap_page_protect(pg, VM_PROT_NONE);
simple_unlock(&anon->an_lock);
uvm_anfree(anon); /* frees page for us */
if (locked)
uvmfault_unlockall(ufi, amap, NULL,
NULL);
uvmexp.fltpgrele++;
return (VM_PAGER_REFAULT); /* refault! */
}
if (result != VM_PAGER_OK) {
KASSERT(result != VM_PAGER_PEND);
/* remove page from anon */
anon->an_page = NULL;
/*
* remove the swap slot from the anon
* and mark the anon as having no real slot.
* don't free the swap slot, thus preventing
* it from being used again.
*/
uvm_swap_markbad(anon->an_swslot, 1);
anon->an_swslot = SWSLOT_BAD;
/*
* note: page was never !PG_BUSY, so it
* can't be mapped and thus no need to
* pmap_page_protect it...
*/
uvm_lock_pageq();
uvm_pagefree(pg);
uvm_unlock_pageq();
if (locked)
uvmfault_unlockall(ufi, amap, NULL,
anon);
else
simple_unlock(&anon->an_lock);
return (VM_PAGER_ERROR);
}
/*
* must be OK, clear modify (already PG_CLEAN)
* and activate
*/
pmap_clear_modify(pg);
uvm_lock_pageq();
uvm_pageactivate(pg);
uvm_unlock_pageq();
if (!locked)
simple_unlock(&anon->an_lock);
}
/*
* we were not able to relock. restart fault.
*/
if (!locked)
return (VM_PAGER_REFAULT);
/*
* verify no one has touched the amap and moved the anon on us.
*/
if (ufi != NULL &&
amap_lookup(&ufi->entry->aref,
ufi->orig_rvaddr - ufi->entry->start) != anon) {
uvmfault_unlockall(ufi, amap, NULL, anon);
return (VM_PAGER_REFAULT);
}
/*
* try it again!
*/
uvmexp.fltanretry++;
continue;
} /* while (1) */
/*NOTREACHED*/
}
int
ufs_balloc_range(struct vnode *vp, off_t off, off_t len, kauth_cred_t cred,
int flags)
{
off_t neweof; /* file size after the operation */
off_t neweob; /* offset next to the last block after the operation */
off_t pagestart; /* starting offset of range covered by pgs */
off_t eob; /* offset next to allocated blocks */
struct uvm_object *uobj;
int i, delta, error, npages;
int bshift = vp->v_mount->mnt_fs_bshift;
int bsize = 1 << bshift;
int ppb = MAX(bsize >> PAGE_SHIFT, 1);
struct vm_page **pgs;
size_t pgssize;
UVMHIST_FUNC("ufs_balloc_range"); UVMHIST_CALLED(ubchist);
UVMHIST_LOG(ubchist, "vp %p off 0x%x len 0x%x u_size 0x%x",
vp, off, len, vp->v_size);
neweof = MAX(vp->v_size, off + len);
GOP_SIZE(vp, neweof, &neweob, 0);
error = 0;
uobj = &vp->v_uobj;
/*
* read or create pages covering the range of the allocation and
* keep them locked until the new block is allocated, so there
* will be no window where the old contents of the new block are
* visible to racing threads.
*/
pagestart = trunc_page(off) & ~(bsize - 1);
npages = MIN(ppb, (round_page(neweob) - pagestart) >> PAGE_SHIFT);
pgssize = npages * sizeof(struct vm_page *);
pgs = kmem_zalloc(pgssize, KM_SLEEP);
mutex_enter(&uobj->vmobjlock);
error = VOP_GETPAGES(vp, pagestart, pgs, &npages, 0,
VM_PROT_WRITE, 0,
PGO_SYNCIO|PGO_PASTEOF|PGO_NOBLOCKALLOC|PGO_NOTIMESTAMP);
if (error) {
goto out;
}
mutex_enter(&uobj->vmobjlock);
mutex_enter(&uvm_pageqlock);
for (i = 0; i < npages; i++) {
UVMHIST_LOG(ubchist, "got pgs[%d] %p", i, pgs[i],0,0);
KASSERT((pgs[i]->flags & PG_RELEASED) == 0);
pgs[i]->flags &= ~PG_CLEAN;
uvm_pageactivate(pgs[i]);
}
mutex_exit(&uvm_pageqlock);
mutex_exit(&uobj->vmobjlock);
/*
* adjust off to be block-aligned.
*/
delta = off & (bsize - 1);
off -= delta;
len += delta;
/*
* now allocate the range.
*/
genfs_node_wrlock(vp);
error = GOP_ALLOC(vp, off, len, flags, cred);
genfs_node_unlock(vp);
/*
* clear PG_RDONLY on any pages we are holding
* (since they now have backing store) and unbusy them.
*/
GOP_SIZE(vp, off + len, &eob, 0);
mutex_enter(&uobj->vmobjlock);
for (i = 0; i < npages; i++) {
if (error) {
pgs[i]->flags |= PG_RELEASED;
} else if (off <= pagestart + (i << PAGE_SHIFT) &&
pagestart + ((i + 1) << PAGE_SHIFT) <= eob) {
pgs[i]->flags &= ~PG_RDONLY;
}
}
if (error) {
mutex_enter(&uvm_pageqlock);
uvm_page_unbusy(pgs, npages);
mutex_exit(&uvm_pageqlock);
} else {
uvm_page_unbusy(pgs, npages);
}
mutex_exit(&uobj->vmobjlock);
out:
kmem_free(pgs, pgssize);
return error;
}
int
ulfs_balloc_range(struct vnode *vp, off_t off, off_t len, kauth_cred_t cred,
int flags)
{
off_t neweof; /* file size after the operation */
off_t neweob; /* offset next to the last block after the operation */
off_t pagestart; /* starting offset of range covered by pgs */
off_t eob; /* offset next to allocated blocks */
struct uvm_object *uobj;
int i, delta, error, npages;
int bshift = vp->v_mount->mnt_fs_bshift;
int bsize = 1 << bshift;
int ppb = MAX(bsize >> PAGE_SHIFT, 1);
struct vm_page **pgs;
size_t pgssize;
UVMHIST_FUNC("ulfs_balloc_range"); UVMHIST_CALLED(ubchist);
UVMHIST_LOG(ubchist, "vp %p off 0x%x len 0x%x u_size 0x%x",
vp, off, len, vp->v_size);
neweof = MAX(vp->v_size, off + len);
GOP_SIZE(vp, neweof, &neweob, 0);
error = 0;
uobj = &vp->v_uobj;
/*
* read or create pages covering the range of the allocation and
* keep them locked until the new block is allocated, so there
* will be no window where the old contents of the new block are
* visible to racing threads.
*/
pagestart = trunc_page(off) & ~(bsize - 1);
npages = MIN(ppb, (round_page(neweob) - pagestart) >> PAGE_SHIFT);
pgssize = npages * sizeof(struct vm_page *);
pgs = kmem_zalloc(pgssize, KM_SLEEP);
/*
* adjust off to be block-aligned.
*/
delta = off & (bsize - 1);
off -= delta;
len += delta;
genfs_node_wrlock(vp);
mutex_enter(uobj->vmobjlock);
error = VOP_GETPAGES(vp, pagestart, pgs, &npages, 0,
VM_PROT_WRITE, 0, PGO_SYNCIO | PGO_PASTEOF | PGO_NOBLOCKALLOC |
PGO_NOTIMESTAMP | PGO_GLOCKHELD);
if (error) {
goto out;
}
/*
* now allocate the range.
*/
error = GOP_ALLOC(vp, off, len, flags, cred);
genfs_node_unlock(vp);
/*
* if the allocation succeeded, clear PG_CLEAN on all the pages
* and clear PG_RDONLY on any pages that are now fully backed
* by disk blocks. if the allocation failed, we do not invalidate
* the pages since they might have already existed and been dirty,
* in which case we need to keep them around. if we created the pages,
* they will be clean and read-only, and leaving such pages
* in the cache won't cause any problems.
*/
GOP_SIZE(vp, off + len, &eob, 0);
mutex_enter(uobj->vmobjlock);
mutex_enter(&uvm_pageqlock);
for (i = 0; i < npages; i++) {
KASSERT((pgs[i]->flags & PG_RELEASED) == 0);
if (!error) {
if (off <= pagestart + (i << PAGE_SHIFT) &&
pagestart + ((i + 1) << PAGE_SHIFT) <= eob) {
pgs[i]->flags &= ~PG_RDONLY;
}
pgs[i]->flags &= ~PG_CLEAN;
}
uvm_pageactivate(pgs[i]);
}
mutex_exit(&uvm_pageqlock);
uvm_page_unbusy(pgs, npages);
mutex_exit(uobj->vmobjlock);
out:
kmem_free(pgs, pgssize);
return error;
}
