diff options
| -rw-r--r-- | sys/fs/tmpfs/tmpfs_subr.c | 78 | ||||
| -rw-r--r-- | sys/kern/uipc_shm.c | 101 |
2 files changed, 113 insertions, 66 deletions
diff --git a/sys/fs/tmpfs/tmpfs_subr.c b/sys/fs/tmpfs/tmpfs_subr.c index e9324cf..e733f19 100644 --- a/sys/fs/tmpfs/tmpfs_subr.c +++ b/sys/fs/tmpfs/tmpfs_subr.c @@ -48,6 +48,7 @@ __FBSDID("$FreeBSD$"); #include <vm/vm.h> #include <vm/vm_object.h> #include <vm/vm_page.h> +#include <vm/vm_pageout.h> #include <vm/vm_pager.h> #include <vm/vm_extern.h> @@ -886,10 +887,10 @@ tmpfs_reg_resize(struct vnode *vp, off_t newsize) struct tmpfs_mount *tmp; struct tmpfs_node *node; vm_object_t uobj; - vm_page_t m; - vm_pindex_t newpages, oldpages; + vm_page_t m, ma[1]; + vm_pindex_t idx, newpages, oldpages; off_t oldsize; - size_t zerolen; + int base, rv; MPASS(vp->v_type == VREG); MPASS(newsize >= 0); @@ -912,15 +913,57 @@ tmpfs_reg_resize(struct vnode *vp, off_t newsize) newpages - oldpages > TMPFS_PAGES_AVAIL(tmp)) return (ENOSPC); - TMPFS_LOCK(tmp); - tmp->tm_pages_used += (newpages - oldpages); - TMPFS_UNLOCK(tmp); - - node->tn_size = newsize; - vnode_pager_setsize(vp, newsize); VM_OBJECT_LOCK(uobj); if (newsize < oldsize) { /* + * Zero the truncated part of the last page. + */ + base = newsize & PAGE_MASK; + if (base != 0) { + idx = OFF_TO_IDX(newsize); +retry: + m = vm_page_lookup(uobj, idx); + if (m != NULL) { + if ((m->oflags & VPO_BUSY) != 0 || + m->busy != 0) { + vm_page_sleep(m, "tmfssz"); + goto retry; + } + } else if (vm_pager_has_page(uobj, idx, NULL, NULL)) { + m = vm_page_alloc(uobj, idx, VM_ALLOC_NORMAL); + if (m == NULL) { + VM_OBJECT_UNLOCK(uobj); + VM_WAIT; + VM_OBJECT_LOCK(uobj); + goto retry; + } else if (m->valid != VM_PAGE_BITS_ALL) { + ma[0] = m; + rv = vm_pager_get_pages(uobj, ma, 1, 0); + m = vm_page_lookup(uobj, idx); + } else + /* A cached page was reactivated. */ + rv = VM_PAGER_OK; + vm_page_lock(m); + if (rv == VM_PAGER_OK) { + vm_page_deactivate(m); + vm_page_unlock(m); + vm_page_wakeup(m); + } else { + vm_page_free(m); + vm_page_unlock(m); + VM_OBJECT_UNLOCK(uobj); + return (EIO); + } + } + if (m != NULL) { + pmap_zero_page_area(m, base, PAGE_SIZE - base); + MPASS(m->valid == VM_PAGE_BITS_ALL); + vm_page_dirty(m); + vm_pager_page_unswapped(m); + } + } + + /* * Release any swap space and free any whole pages. */ if (newpages < oldpages) { @@ -928,19 +971,16 @@ tmpfs_reg_resize(struct vnode *vp, off_t newsize) newpages); vm_object_page_remove(uobj, newpages, 0, 0); } - - /* - * Zero the truncated part of the last page. - */ - zerolen = round_page(newsize) - newsize; - if (zerolen > 0) { - m = vm_page_grab(uobj, OFF_TO_IDX(newsize), - VM_ALLOC_NOBUSY | VM_ALLOC_NORMAL | VM_ALLOC_RETRY); - pmap_zero_page_area(m, PAGE_SIZE - zerolen, zerolen); - } } uobj->size = newpages; VM_OBJECT_UNLOCK(uobj); + + TMPFS_LOCK(tmp); + tmp->tm_pages_used += (newpages - oldpages); + TMPFS_UNLOCK(tmp); + + node->tn_size = newsize; + vnode_pager_setsize(vp, newsize); return (0); } diff --git a/sys/kern/uipc_shm.c b/sys/kern/uipc_shm.c index 4d064b5..ce7c722 100644 --- a/sys/kern/uipc_shm.c +++ b/sys/kern/uipc_shm.c @@ -39,13 +39,6 @@ * * (3) Resource limits? Does this need its own resource limits or are the * existing limits in mmap(2) sufficient? - * - * (4) Partial page truncation. vnode_pager_setsize() will zero any parts - * of a partially mapped page as a result of ftruncate(2)/truncate(2). - * We can do the same (with the same pmap evil), but do we need to - * worry about the bits on disk if the page is swapped out or will the - * swapper zero the parts of a page that are invalid if the page is - * swapped back in for us? */ #include <sys/cdefs.h> @@ -86,6 +79,7 @@ __FBSDID("$FreeBSD$"); #include <vm/vm_kern.h> #include <vm/vm_object.h> #include <vm/vm_page.h> +#include <vm/vm_pageout.h> #include <vm/vm_pager.h> #include <vm/swap_pager.h> @@ -253,9 +247,10 @@ static int shm_dotruncate(struct shmfd *shmfd, off_t length) { vm_object_t object; - vm_page_t m; - vm_pindex_t nobjsize; + vm_page_t m, ma[1]; + vm_pindex_t idx, nobjsize; vm_ooffset_t delta; + int base, rv; object = shmfd->shm_object; VM_OBJECT_LOCK(object); @@ -275,6 +270,56 @@ shm_dotruncate(struct shmfd *shmfd, off_t length) VM_OBJECT_UNLOCK(object); return (EBUSY); } + + /* + * Zero the truncated part of the last page. + */ + base = length & PAGE_MASK; + if (base != 0) { + idx = OFF_TO_IDX(length); +retry: + m = vm_page_lookup(object, idx); + if (m != NULL) { + if ((m->oflags & VPO_BUSY) != 0 || + m->busy != 0) { + vm_page_sleep(m, "shmtrc"); + goto retry; + } + } else if (vm_pager_has_page(object, idx, NULL, NULL)) { + m = vm_page_alloc(object, idx, VM_ALLOC_NORMAL); + if (m == NULL) { + VM_OBJECT_UNLOCK(object); + VM_WAIT; + VM_OBJECT_LOCK(object); + goto retry; + } else if (m->valid != VM_PAGE_BITS_ALL) { + ma[0] = m; + rv = vm_pager_get_pages(object, ma, 1, + 0); + m = vm_page_lookup(object, idx); + } else + /* A cached page was reactivated. */ + rv = VM_PAGER_OK; + vm_page_lock(m); + if (rv == VM_PAGER_OK) { + vm_page_deactivate(m); + vm_page_unlock(m); + vm_page_wakeup(m); + } else { + vm_page_free(m); + vm_page_unlock(m); + VM_OBJECT_UNLOCK(object); + return (EIO); + } + } + if (m != NULL) { + pmap_zero_page_area(m, base, PAGE_SIZE - base); + KASSERT(m->valid == VM_PAGE_BITS_ALL, + ("shm_dotruncate: page %p is invalid", m)); + vm_page_dirty(m); + vm_pager_page_unswapped(m); + } + } delta = ptoa(object->size - nobjsize); /* Toss in memory pages. */ @@ -289,45 +334,7 @@ shm_dotruncate(struct shmfd *shmfd, off_t length) /* Free the swap accounted for shm */ swap_release_by_cred(delta, object->cred); object->charge -= delta; - - /* - * If the last page is partially mapped, then zero out - * the garbage at the end of the page. See comments - * in vnode_pager_setsize() for more details. - * - * XXXJHB: This handles in memory pages, but what about - * a page swapped out to disk? - */ - if ((length & PAGE_MASK) && - (m = vm_page_lookup(object, OFF_TO_IDX(length))) != NULL && - m->valid != 0) { - int base = (int)length & PAGE_MASK; - int size = PAGE_SIZE - base; - - pmap_zero_page_area(m, base, size); - - /* - * Update the valid bits to reflect the blocks that - * have been zeroed. Some of these valid bits may - * have already been set. - */ - vm_page_set_valid_range(m, base, size); - - /* - * Round "base" to the next block boundary so that the - * dirty bit for a partially zeroed block is not - * cleared. - */ - base = roundup2(base, DEV_BSIZE); - - vm_page_clear_dirty(m, base, PAGE_SIZE - base); - } else if ((length & PAGE_MASK) && - __predict_false(object->cache != NULL)) { - vm_page_cache_free(object, OFF_TO_IDX(length), - nobjsize); - } } else { - /* Attempt to reserve the swap */ delta = ptoa(nobjsize - object->size); if (!swap_reserve_by_cred(delta, object->cred)) { |
