/* $NetBSD: genfs_io.c,v 1.58 2013/10/25 11:35:55 martin Exp $ */ /* * Copyright (c) 1982, 1986, 1989, 1993 * The Regents of the University of California. 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. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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. * */ #include __KERNEL_RCSID(0, "$NetBSD: genfs_io.c,v 1.58 2013/10/25 11:35:55 martin Exp $"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static int genfs_do_directio(struct vmspace *, vaddr_t, size_t, struct vnode *, off_t, enum uio_rw); static void genfs_dio_iodone(struct buf *); static int genfs_do_io(struct vnode *, off_t, vaddr_t, size_t, int, enum uio_rw, void (*)(struct buf *)); static void genfs_rel_pages(struct vm_page **, unsigned int); static void genfs_markdirty(struct vnode *); int genfs_maxdio = MAXPHYS; static void genfs_rel_pages(struct vm_page **pgs, unsigned int npages) { unsigned int i; for (i = 0; i < npages; i++) { struct vm_page *pg = pgs[i]; if (pg == NULL || pg == PGO_DONTCARE) continue; KASSERT(uvm_page_locked_p(pg)); if (pg->flags & PG_FAKE) { pg->flags |= PG_RELEASED; } } mutex_enter(&uvm_pageqlock); uvm_page_unbusy(pgs, npages); mutex_exit(&uvm_pageqlock); } static void genfs_markdirty(struct vnode *vp) { struct genfs_node * const gp = VTOG(vp); KASSERT(mutex_owned(vp->v_interlock)); gp->g_dirtygen++; if ((vp->v_iflag & VI_ONWORKLST) == 0) { vn_syncer_add_to_worklist(vp, filedelay); } if ((vp->v_iflag & (VI_WRMAP|VI_WRMAPDIRTY)) == VI_WRMAP) { vp->v_iflag |= VI_WRMAPDIRTY; } } /* * generic VM getpages routine. * Return PG_BUSY pages for the given range, * reading from backing store if necessary. */ int genfs_getpages(void *v) { struct vop_getpages_args /* { struct vnode *a_vp; voff_t a_offset; struct vm_page **a_m; int *a_count; int a_centeridx; vm_prot_t a_access_type; int a_advice; int a_flags; } */ * const ap = v; off_t diskeof, memeof; int i, error, npages; const int flags = ap->a_flags; struct vnode * const vp = ap->a_vp; struct uvm_object * const uobj = &vp->v_uobj; kauth_cred_t const cred = curlwp->l_cred; /* XXXUBC curlwp */ const bool async = (flags & PGO_SYNCIO) == 0; const bool memwrite = (ap->a_access_type & VM_PROT_WRITE) != 0; const bool overwrite = (flags & PGO_OVERWRITE) != 0; const bool blockalloc = memwrite && (flags & PGO_NOBLOCKALLOC) == 0; const bool glocked = (flags & PGO_GLOCKHELD) != 0; const bool need_wapbl = blockalloc && vp->v_mount->mnt_wapbl; bool has_trans_wapbl = false; UVMHIST_FUNC("genfs_getpages"); UVMHIST_CALLED(ubchist); UVMHIST_LOG(ubchist, "vp %p off 0x%x/%x count %d", vp, ap->a_offset >> 32, ap->a_offset, *ap->a_count); KASSERT(vp->v_type == VREG || vp->v_type == VDIR || vp->v_type == VLNK || vp->v_type == VBLK); startover: error = 0; const voff_t origvsize = vp->v_size; const off_t origoffset = ap->a_offset; const int orignpages = *ap->a_count; GOP_SIZE(vp, origvsize, &diskeof, 0); if (flags & PGO_PASTEOF) { off_t newsize; #if defined(DIAGNOSTIC) off_t writeeof; #endif /* defined(DIAGNOSTIC) */ newsize = MAX(origvsize, origoffset + (orignpages << PAGE_SHIFT)); GOP_SIZE(vp, newsize, &memeof, GOP_SIZE_MEM); #if defined(DIAGNOSTIC) GOP_SIZE(vp, vp->v_writesize, &writeeof, GOP_SIZE_MEM); if (newsize > round_page(writeeof)) { panic("%s: past eof: %" PRId64 " vs. %" PRId64, __func__, newsize, round_page(writeeof)); } #endif /* defined(DIAGNOSTIC) */ } else { GOP_SIZE(vp, origvsize, &memeof, GOP_SIZE_MEM); } KASSERT(ap->a_centeridx >= 0 || ap->a_centeridx <= orignpages); KASSERT((origoffset & (PAGE_SIZE - 1)) == 0 && origoffset >= 0); KASSERT(orignpages > 0); /* * Bounds-check the request. */ if (origoffset + (ap->a_centeridx << PAGE_SHIFT) >= memeof) { if ((flags & PGO_LOCKED) == 0) { mutex_exit(uobj->vmobjlock); } UVMHIST_LOG(ubchist, "off 0x%x count %d goes past EOF 0x%x", origoffset, *ap->a_count, memeof,0); error = EINVAL; goto out_err; } /* uobj is locked */ if ((flags & PGO_NOTIMESTAMP) == 0 && (vp->v_type != VBLK || (vp->v_mount->mnt_flag & MNT_NODEVMTIME) == 0)) { int updflags = 0; if ((vp->v_mount->mnt_flag & MNT_NOATIME) == 0) { updflags = GOP_UPDATE_ACCESSED; } if (memwrite) { updflags |= GOP_UPDATE_MODIFIED; } if (updflags != 0) { GOP_MARKUPDATE(vp, updflags); } } /* * For PGO_LOCKED requests, just return whatever's in memory. */ if (flags & PGO_LOCKED) { int nfound; struct vm_page *pg; KASSERT(!glocked); npages = *ap->a_count; #if defined(DEBUG) for (i = 0; i < npages; i++) { pg = ap->a_m[i]; KASSERT(pg == NULL || pg == PGO_DONTCARE); } #endif /* defined(DEBUG) */ nfound = uvn_findpages(uobj, origoffset, &npages, ap->a_m, UFP_NOWAIT|UFP_NOALLOC|(memwrite ? UFP_NORDONLY : 0)); KASSERT(npages == *ap->a_count); if (nfound == 0) { error = EBUSY; goto out_err; } if (!genfs_node_rdtrylock(vp)) { genfs_rel_pages(ap->a_m, npages); /* * restore the array. */ for (i = 0; i < npages; i++) { pg = ap->a_m[i]; if (pg != NULL && pg != PGO_DONTCARE) { ap->a_m[i] = NULL; } KASSERT(ap->a_m[i] == NULL || ap->a_m[i] == PGO_DONTCARE); } } else { genfs_node_unlock(vp); } error = (ap->a_m[ap->a_centeridx] == NULL ? EBUSY : 0); if (error == 0 && memwrite) { genfs_markdirty(vp); } goto out_err; } mutex_exit(uobj->vmobjlock); /* * find the requested pages and make some simple checks. * leave space in the page array for a whole block. */ const int fs_bshift = (vp->v_type != VBLK) ? vp->v_mount->mnt_fs_bshift : DEV_BSHIFT; const int dev_bshift = (vp->v_type != VBLK) ? vp->v_mount->mnt_dev_bshift : DEV_BSHIFT; const int fs_bsize = 1 << fs_bshift; #define blk_mask (fs_bsize - 1) #define trunc_blk(x) ((x) & ~blk_mask) #define round_blk(x) (((x) + blk_mask) & ~blk_mask) const int orignmempages = MIN(orignpages, round_page(memeof - origoffset) >> PAGE_SHIFT); npages = orignmempages; const off_t startoffset = trunc_blk(origoffset); const off_t endoffset = MIN( round_page(round_blk(origoffset + (npages << PAGE_SHIFT))), round_page(memeof)); const int ridx = (origoffset - startoffset) >> PAGE_SHIFT; const int pgs_size = sizeof(struct vm_page *) * ((endoffset - startoffset) >> PAGE_SHIFT); struct vm_page **pgs, *pgs_onstack[UBC_MAX_PAGES]; if (pgs_size > sizeof(pgs_onstack)) { pgs = kmem_zalloc(pgs_size, async ? KM_NOSLEEP : KM_SLEEP); if (pgs == NULL) { pgs = pgs_onstack; error = ENOMEM; goto out_err; } } else { pgs = pgs_onstack; (void)memset(pgs, 0, pgs_size); } UVMHIST_LOG(ubchist, "ridx %d npages %d startoff %ld endoff %ld", ridx, npages, startoffset, endoffset); if (!has_trans_wapbl) { fstrans_start(vp->v_mount, FSTRANS_SHARED); /* * XXX: This assumes that we come here only via * the mmio path */ if (need_wapbl) { error = WAPBL_BEGIN(vp->v_mount); if (error) { fstrans_done(vp->v_mount); goto out_err_free; } } has_trans_wapbl = true; } /* * hold g_glock to prevent a race with truncate. * * check if our idea of v_size is still valid. */ KASSERT(!glocked || genfs_node_wrlocked(vp)); if (!glocked) { if (blockalloc) { genfs_node_wrlock(vp); } else { genfs_node_rdlock(vp); } } mutex_enter(uobj->vmobjlock); if (vp->v_size < origvsize) { if (!glocked) { genfs_node_unlock(vp); } if (pgs != pgs_onstack) kmem_free(pgs, pgs_size); goto startover; } if (uvn_findpages(uobj, origoffset, &npages, &pgs[ridx], async ? UFP_NOWAIT : UFP_ALL) != orignmempages) { if (!glocked) { genfs_node_unlock(vp); } KASSERT(async != 0); genfs_rel_pages(&pgs[ridx], orignmempages); mutex_exit(uobj->vmobjlock); error = EBUSY; goto out_err_free; } /* * if the pages are already resident, just return them. */ for (i = 0; i < npages; i++) { struct vm_page *pg = pgs[ridx + i]; if ((pg->flags & PG_FAKE) || (blockalloc && (pg->flags & PG_RDONLY))) { break; } } if (i == npages) { if (!glocked) { genfs_node_unlock(vp); } UVMHIST_LOG(ubchist, "returning cached pages", 0,0,0,0); npages += ridx; goto out; } /* * if PGO_OVERWRITE is set, don't bother reading the pages. */ if (overwrite) { if (!glocked) { genfs_node_unlock(vp); } UVMHIST_LOG(ubchist, "PGO_OVERWRITE",0,0,0,0); for (i = 0; i < npages; i++) { struct vm_page *pg = pgs[ridx + i]; pg->flags &= ~(PG_RDONLY|PG_CLEAN); } npages += ridx; goto out; } /* * the page wasn't resident and we're not overwriting, * so we're going to have to do some i/o. * find any additional pages needed to cover the expanded range. */ npages = (endoffset - startoffset) >> PAGE_SHIFT; if (startoffset != origoffset || npages != orignmempages) { int npgs; /* * we need to avoid deadlocks caused by locking * additional pages at lower offsets than pages we * already have locked. unlock them all and start over. */ genfs_rel_pages(&pgs[ridx], orignmempages); memset(pgs, 0, pgs_size); UVMHIST_LOG(ubchist, "reset npages start 0x%x end 0x%x", startoffset, endoffset, 0,0); npgs = npages; if (uvn_findpages(uobj, startoffset, &npgs, pgs, async ? UFP_NOWAIT : UFP_ALL) != npages) { if (!glocked) { genfs_node_unlock(vp); } KASSERT(async != 0); genfs_rel_pages(pgs, npages); mutex_exit(uobj->vmobjlock); error = EBUSY; goto out_err_free; } } mutex_exit(uobj->vmobjlock); { size_t bytes, iobytes, tailstart, tailbytes, totalbytes, skipbytes; vaddr_t kva; struct buf *bp, *mbp; bool sawhole = false; /* * read the desired page(s). */ totalbytes = npages << PAGE_SHIFT; bytes = MIN(totalbytes, MAX(diskeof - startoffset, 0)); tailbytes = totalbytes - bytes; skipbytes = 0; kva = uvm_pagermapin(pgs, npages, UVMPAGER_MAPIN_READ | (async ? 0 : UVMPAGER_MAPIN_WAITOK)); if (kva == 0) { error = EBUSY; goto mapin_fail; } mbp = getiobuf(vp, true); mbp->b_bufsize = totalbytes; mbp->b_data = (void *)kva; mbp->b_resid = mbp->b_bcount = bytes; mbp->b_cflags = BC_BUSY; if (async) { mbp->b_flags = B_READ | B_ASYNC; mbp->b_iodone = uvm_aio_biodone; } else { mbp->b_flags = B_READ; mbp->b_iodone = NULL; } if (async) BIO_SETPRIO(mbp, BPRIO_TIMELIMITED); else BIO_SETPRIO(mbp, BPRIO_TIMECRITICAL); /* * if EOF is in the middle of the range, zero the part past EOF. * skip over pages which are not PG_FAKE since in that case they have * valid data that we need to preserve. */ tailstart = bytes; while (tailbytes > 0) { const int len = PAGE_SIZE - (tailstart & PAGE_MASK); KASSERT(len <= tailbytes); if ((pgs[tailstart >> PAGE_SHIFT]->flags & PG_FAKE) != 0) { memset((void *)(kva + tailstart), 0, len); UVMHIST_LOG(ubchist, "tailbytes %p 0x%x 0x%x", kva, tailstart, len, 0); } tailstart += len; tailbytes -= len; } /* * now loop over the pages, reading as needed. */ bp = NULL; off_t offset; for (offset = startoffset; bytes > 0; offset += iobytes, bytes -= iobytes) { int run; daddr_t lbn, blkno; int pidx; struct vnode *devvp; /* * skip pages which don't need to be read. */ pidx = (offset - startoffset) >> PAGE_SHIFT; while ((pgs[pidx]->flags & PG_FAKE) == 0) { size_t b; KASSERT((offset & (PAGE_SIZE - 1)) == 0); if ((pgs[pidx]->flags & PG_RDONLY)) { sawhole = true; } b = MIN(PAGE_SIZE, bytes); offset += b; bytes -= b; skipbytes += b; pidx++; UVMHIST_LOG(ubchist, "skipping, new offset 0x%x", offset, 0,0,0); if (bytes == 0) { goto loopdone; } } /* * bmap the file to find out the blkno to read from and * how much we can read in one i/o. if bmap returns an error, * skip the rest of the top-level i/o. */ lbn = offset >> fs_bshift; error = VOP_BMAP(vp, lbn, &devvp, &blkno, &run); if (error) { UVMHIST_LOG(ubchist, "VOP_BMAP lbn 0x%x -> %d\n", lbn,error,0,0); skipbytes += bytes; bytes = 0; goto loopdone; } /* * see how many pages can be read with this i/o. * reduce the i/o size if necessary to avoid * overwriting pages with valid data. */ iobytes = MIN((((off_t)lbn + 1 + run) << fs_bshift) - offset, bytes); if (offset + iobytes > round_page(offset)) { int pcount; pcount = 1; while (pidx + pcount < npages && pgs[pidx + pcount]->flags & PG_FAKE) { pcount++; } iobytes = MIN(iobytes, (pcount << PAGE_SHIFT) - (offset - trunc_page(offset))); } /* * if this block isn't allocated, zero it instead of * reading it. unless we are going to allocate blocks, * mark the pages we zeroed PG_RDONLY. */ if (blkno == (daddr_t)-1) { int holepages = (round_page(offset + iobytes) - trunc_page(offset)) >> PAGE_SHIFT; UVMHIST_LOG(ubchist, "lbn 0x%x -> HOLE", lbn,0,0,0); sawhole = true; memset((char *)kva + (offset - startoffset), 0, iobytes); skipbytes += iobytes; mutex_enter(uobj->vmobjlock); for (i = 0; i < holepages; i++) { if (memwrite) { pgs[pidx + i]->flags &= ~PG_CLEAN; } if (!blockalloc) { pgs[pidx + i]->flags |= PG_RDONLY; } } mutex_exit(uobj->vmobjlock); continue; } /* * allocate a sub-buf for this piece of the i/o * (or just use mbp if there's only 1 piece), * and start it going. */ if (offset == startoffset && iobytes == bytes) { bp = mbp; } else { UVMHIST_LOG(ubchist, "vp %p bp %p num now %d", vp, bp, vp->v_numoutput, 0); bp = getiobuf(vp, true); nestiobuf_setup(mbp, bp, offset - startoffset, iobytes); } bp->b_lblkno = 0; /* adjust physical blkno for partial blocks */ bp->b_blkno = blkno + ((offset - ((off_t)lbn << fs_bshift)) >> dev_bshift); UVMHIST_LOG(ubchist, "bp %p offset 0x%x bcount 0x%x blkno 0x%x", bp, offset, bp->b_bcount, bp->b_blkno); VOP_STRATEGY(devvp, bp); } loopdone: nestiobuf_done(mbp, skipbytes, error); if (async) { UVMHIST_LOG(ubchist, "returning 0 (async)",0,0,0,0); if (!glocked) { genfs_node_unlock(vp); } error = 0; goto out_err_free; } if (bp != NULL) { error = biowait(mbp); } /* Remove the mapping (make KVA available as soon as possible) */ uvm_pagermapout(kva, npages); /* * if this we encountered a hole then we have to do a little more work. * for read faults, we marked the page PG_RDONLY so that future * write accesses to the page will fault again. * for write faults, we must make sure that the backing store for * the page is completely allocated while the pages are locked. */ if (!error && sawhole && blockalloc) { error = GOP_ALLOC(vp, startoffset, npages << PAGE_SHIFT, 0, cred); UVMHIST_LOG(ubchist, "gop_alloc off 0x%x/0x%x -> %d", startoffset, npages << PAGE_SHIFT, error,0); if (!error) { mutex_enter(uobj->vmobjlock); for (i = 0; i < npages; i++) { struct vm_page *pg = pgs[i]; if (pg == NULL) { continue; } pg->flags &= ~(PG_CLEAN|PG_RDONLY); UVMHIST_LOG(ubchist, "mark dirty pg %p", pg,0,0,0); } mutex_exit(uobj->vmobjlock); } } putiobuf(mbp); } mapin_fail: if (!glocked) { genfs_node_unlock(vp); } mutex_enter(uobj->vmobjlock); /* * we're almost done! release the pages... * for errors, we free the pages. * otherwise we activate them and mark them as valid and clean. * also, unbusy pages that were not actually requested. */ if (error) { genfs_rel_pages(pgs, npages); mutex_exit(uobj->vmobjlock); UVMHIST_LOG(ubchist, "returning error %d", error,0,0,0); goto out_err_free; } out: UVMHIST_LOG(ubchist, "succeeding, npages %d", npages,0,0,0); error = 0; mutex_enter(&uvm_pageqlock); for (i = 0; i < npages; i++) { struct vm_page *pg = pgs[i]; if (pg == NULL) { continue; } UVMHIST_LOG(ubchist, "examining pg %p flags 0x%x", pg, pg->flags, 0,0); if (pg->flags & PG_FAKE && !overwrite) { pg->flags &= ~(PG_FAKE); pmap_clear_modify(pgs[i]); } KASSERT(!memwrite || !blockalloc || (pg->flags & PG_RDONLY) == 0); if (i < ridx || i >= ridx + orignmempages || async) { UVMHIST_LOG(ubchist, "unbusy pg %p offset 0x%x", pg, pg->offset,0,0); if (pg->flags & PG_WANTED) { wakeup(pg); } if (pg->flags & PG_FAKE) { KASSERT(overwrite); uvm_pagezero(pg); } if (pg->flags & PG_RELEASED) { uvm_pagefree(pg); continue; } uvm_pageenqueue(pg); pg->flags &= ~(PG_WANTED|PG_BUSY|PG_FAKE); UVM_PAGE_OWN(pg, NULL); } } mutex_exit(&uvm_pageqlock); if (memwrite) { genfs_markdirty(vp); } mutex_exit(uobj->vmobjlock); if (ap->a_m != NULL) { memcpy(ap->a_m, &pgs[ridx], orignmempages * sizeof(struct vm_page *)); } out_err_free: if (pgs != NULL && pgs != pgs_onstack) kmem_free(pgs, pgs_size); out_err: if (has_trans_wapbl) { if (need_wapbl) WAPBL_END(vp->v_mount); fstrans_done(vp->v_mount); } return error; } /* * generic VM putpages routine. * Write the given range of pages to backing store. * * => "offhi == 0" means flush all pages at or after "offlo". * => object should be locked by caller. we return with the * object unlocked. * => if PGO_CLEANIT or PGO_SYNCIO is set, we may block (due to I/O). * thus, a caller might want to unlock higher level resources * (e.g. vm_map) before calling flush. * => if neither PGO_CLEANIT nor PGO_SYNCIO is set, we will not block * => if PGO_ALLPAGES is set, then all pages in the object will be processed. * => NOTE: we rely on the fact that the object's memq is a TAILQ and * that new pages are inserted on the tail end of the list. thus, * we can make a complete pass through the object in one go by starting * at the head and working towards the tail (new pages are put in * front of us). * => NOTE: we are allowed to lock the page queues, so the caller * must not be holding the page queue lock. * * note on "cleaning" object and PG_BUSY pages: * this routine is holding the lock on the object. the only time * that it can run into a PG_BUSY page that it does not own is if * some other process has started I/O on the page (e.g. either * a pagein, or a pageout). if the PG_BUSY page is being paged * in, then it can not be dirty (!PG_CLEAN) because no one has * had a chance to modify it yet. if the PG_BUSY page is being * paged out then it means that someone else has already started * cleaning the page for us (how nice!). in this case, if we * have syncio specified, then after we make our pass through the * object we need to wait for the other PG_BUSY pages to clear * off (i.e. we need to do an iosync). also note that once a * page is PG_BUSY it must stay in its object until it is un-busyed. * * note on page traversal: * we can traverse the pages in an object either by going down the * linked list in "uobj->memq", or we can go over the address range * by page doing hash table lookups for each address. depending * on how many pages are in the object it may be cheaper to do one * or the other. we set "by_list" to true if we are using memq. * if the cost of a hash lookup was equal to the cost of the list * traversal we could compare the number of pages in the start->stop * range to the total number of pages in the object. however, it * seems that a hash table lookup is more expensive than the linked * list traversal, so we multiply the number of pages in the * range by an estimate of the relatively higher cost of the hash lookup. */ int genfs_putpages(void *v) { struct vop_putpages_args /* { struct vnode *a_vp; voff_t a_offlo; voff_t a_offhi; int a_flags; } */ * const ap = v; return genfs_do_putpages(ap->a_vp, ap->a_offlo, ap->a_offhi, ap->a_flags, NULL); } int genfs_do_putpages(struct vnode *vp, off_t startoff, off_t endoff, int origflags, struct vm_page **busypg) { struct uvm_object * const uobj = &vp->v_uobj; kmutex_t * const slock = uobj->vmobjlock; off_t off; /* Even for strange MAXPHYS, the shift rounds down to a page */ #define maxpages (MAXPHYS >> PAGE_SHIFT) int i, error, npages, nback; int freeflag; struct vm_page *pgs[maxpages], *pg, *nextpg, *tpg, curmp, endmp; bool wasclean, by_list, needs_clean, yld; bool async = (origflags & PGO_SYNCIO) == 0; bool pagedaemon = curlwp == uvm.pagedaemon_lwp; struct lwp * const l = curlwp ? curlwp : &lwp0; struct genfs_node * const gp = VTOG(vp); int flags; int dirtygen; bool modified; bool need_wapbl; bool has_trans; bool cleanall; bool onworklst; UVMHIST_FUNC("genfs_putpages"); UVMHIST_CALLED(ubchist); KASSERT(origflags & (PGO_CLEANIT|PGO_FREE|PGO_DEACTIVATE)); KASSERT((startoff & PAGE_MASK) == 0 && (endoff & PAGE_MASK) == 0); KASSERT(startoff < endoff || endoff == 0); UVMHIST_LOG(ubchist, "vp %p pages %d off 0x%x len 0x%x", vp, uobj->uo_npages, startoff, endoff - startoff); has_trans = false; need_wapbl = (!pagedaemon && vp->v_mount && vp->v_mount->mnt_wapbl && (origflags & PGO_JOURNALLOCKED) == 0); retry: modified = false; flags = origflags; KASSERT((vp->v_iflag & VI_ONWORKLST) != 0 || (vp->v_iflag & VI_WRMAPDIRTY) == 0); if (uobj->uo_npages == 0) { if (vp->v_iflag & VI_ONWORKLST) { vp->v_iflag &= ~VI_WRMAPDIRTY; if (LIST_FIRST(&vp->v_dirtyblkhd) == NULL) vn_syncer_remove_from_worklist(vp); } if (has_trans) { if (need_wapbl) WAPBL_END(vp->v_mount); fstrans_done(vp->v_mount); } mutex_exit(slock); return (0); } /* * the vnode has pages, set up to process the request. */ if (!has_trans && (flags & PGO_CLEANIT) != 0) { mutex_exit(slock); if (pagedaemon) { error = fstrans_start_nowait(vp->v_mount, FSTRANS_LAZY); if (error) return error; } else fstrans_start(vp->v_mount, FSTRANS_LAZY); if (need_wapbl) { error = WAPBL_BEGIN(vp->v_mount); if (error) { fstrans_done(vp->v_mount); return error; } } has_trans = true; mutex_enter(slock); goto retry; } error = 0; wasclean = (vp->v_numoutput == 0); off = startoff; if (endoff == 0 || flags & PGO_ALLPAGES) { endoff = trunc_page(LLONG_MAX); } by_list = (uobj->uo_npages <= ((endoff - startoff) >> PAGE_SHIFT) * UVM_PAGE_TREE_PENALTY); /* * if this vnode is known not to have dirty pages, * don't bother to clean it out. */ if ((vp->v_iflag & VI_ONWORKLST) == 0) { #if !defined(DEBUG) if ((flags & (PGO_FREE|PGO_DEACTIVATE)) == 0) { goto skip_scan; } #endif /* !defined(DEBUG) */ flags &= ~PGO_CLEANIT; } /* * start the loop. when scanning by list, hold the last page * in the list before we start. pages allocated after we start * will be added to the end of the list, so we can stop at the * current last page. */ cleanall = (flags & PGO_CLEANIT) != 0 && wasclean && startoff == 0 && endoff == trunc_page(LLONG_MAX) && (vp->v_iflag & VI_ONWORKLST) != 0; dirtygen = gp->g_dirtygen; freeflag = pagedaemon ? PG_PAGEOUT : PG_RELEASED; if (by_list) { curmp.flags = PG_MARKER; endmp.flags = PG_MARKER; pg = TAILQ_FIRST(&uobj->memq); TAILQ_INSERT_TAIL(&uobj->memq, &endmp, listq.queue); } else { pg = uvm_pagelookup(uobj, off); } nextpg = NULL; while (by_list || off < endoff) { /* * if the current page is not interesting, move on to the next. */ KASSERT(pg == NULL || pg->uobject == uobj || (pg->flags & PG_MARKER) != 0); KASSERT(pg == NULL || (pg->flags & (PG_RELEASED|PG_PAGEOUT)) == 0 || (pg->flags & (PG_BUSY|PG_MARKER)) != 0); if (by_list) { if (pg == &endmp) { break; } if (pg->flags & PG_MARKER) { pg = TAILQ_NEXT(pg, listq.queue); continue; } if (pg->offset < startoff || pg->offset >= endoff || pg->flags & (PG_RELEASED|PG_PAGEOUT)) { if (pg->flags & (PG_RELEASED|PG_PAGEOUT)) { wasclean = false; } pg = TAILQ_NEXT(pg, listq.queue); continue; } off = pg->offset; } else if (pg == NULL || pg->flags & (PG_RELEASED|PG_PAGEOUT)) { if (pg != NULL) { wasclean = false; } off += PAGE_SIZE; if (off < endoff) { pg = uvm_pagelookup(uobj, off); } continue; } /* * if the current page needs to be cleaned and it's busy, * wait for it to become unbusy. */ yld = (l->l_cpu->ci_schedstate.spc_flags & SPCF_SHOULDYIELD) && !pagedaemon; if (pg->flags & PG_BUSY || yld) { UVMHIST_LOG(ubchist, "busy %p", pg,0,0,0); if (flags & PGO_BUSYFAIL && pg->flags & PG_BUSY) { UVMHIST_LOG(ubchist, "busyfail %p", pg, 0,0,0); error = EDEADLK; if (busypg != NULL) *busypg = pg; break; } if (pagedaemon) { /* * someone has taken the page while we * dropped the lock for fstrans_start. */ break; } if (by_list) { TAILQ_INSERT_BEFORE(pg, &curmp, listq.queue); UVMHIST_LOG(ubchist, "curmp next %p", TAILQ_NEXT(&curmp, listq.queue), 0,0,0); } if (yld) { mutex_exit(slock); preempt(); mutex_enter(slock); } else { pg->flags |= PG_WANTED; UVM_UNLOCK_AND_WAIT(pg, slock, 0, "genput", 0); mutex_enter(slock); } if (by_list) { UVMHIST_LOG(ubchist, "after next %p", TAILQ_NEXT(&curmp, listq.queue), 0,0,0); pg = TAILQ_NEXT(&curmp, listq.queue); TAILQ_REMOVE(&uobj->memq, &curmp, listq.queue); } else { pg = uvm_pagelookup(uobj, off); } continue; } /* * if we're freeing, remove all mappings of the page now. * if we're cleaning, check if the page is needs to be cleaned. */ if (flags & PGO_FREE) { pmap_page_protect(pg, VM_PROT_NONE); } else if (flags & PGO_CLEANIT) { /* * if we still have some hope to pull this vnode off * from the syncer queue, write-protect the page. */ if (cleanall && wasclean && gp->g_dirtygen == dirtygen) { /* * uobj pages get wired only by uvm_fault * where uobj is locked. */ if (pg->wire_count == 0) { pmap_page_protect(pg, VM_PROT_READ|VM_PROT_EXECUTE); } else { cleanall = false; } } } if (flags & PGO_CLEANIT) { needs_clean = pmap_clear_modify(pg) || (pg->flags & PG_CLEAN) == 0; pg->flags |= PG_CLEAN; } else { needs_clean = false; } /* * if we're cleaning, build a cluster. * the cluster will consist of pages which are currently dirty, * but they will be returned to us marked clean. * if not cleaning, just operate on the one page. */ if (needs_clean) { KDASSERT((vp->v_iflag & VI_ONWORKLST)); wasclean = false; memset(pgs, 0, sizeof(pgs)); pg->flags |= PG_BUSY; UVM_PAGE_OWN(pg, "genfs_putpages"); /* * first look backward. */ npages = MIN(maxpages >> 1, off >> PAGE_SHIFT); nback = npages; uvn_findpages(uobj, off - PAGE_SIZE, &nback, &pgs[0], UFP_NOWAIT|UFP_NOALLOC|UFP_DIRTYONLY|UFP_BACKWARD); if (nback) { memmove(&pgs[0], &pgs[npages - nback], nback * sizeof(pgs[0])); if (npages - nback < nback) memset(&pgs[nback], 0, (npages - nback) * sizeof(pgs[0])); else memset(&pgs[npages - nback], 0, nback * sizeof(pgs[0])); } /* * then plug in our page of interest. */ pgs[nback] = pg; /* * then look forward to fill in the remaining space in * the array of pages. */ npages = maxpages - nback - 1; uvn_findpages(uobj, off + PAGE_SIZE, &npages, &pgs[nback + 1], UFP_NOWAIT|UFP_NOALLOC|UFP_DIRTYONLY); npages += nback + 1; } else { pgs[0] = pg; npages = 1; nback = 0; } /* * apply FREE or DEACTIVATE options if requested. */ if (flags & (PGO_DEACTIVATE|PGO_FREE)) { mutex_enter(&uvm_pageqlock); } for (i = 0; i < npages; i++) { tpg = pgs[i]; KASSERT(tpg->uobject == uobj); if (by_list && tpg == TAILQ_NEXT(pg, listq.queue)) pg = tpg; if (tpg->offset < startoff || tpg->offset >= endoff) continue; if (flags & PGO_DEACTIVATE && tpg->wire_count == 0) { uvm_pagedeactivate(tpg); } else if (flags & PGO_FREE) { pmap_page_protect(tpg, VM_PROT_NONE); if (tpg->flags & PG_BUSY) { tpg->flags |= freeflag; if (pagedaemon) { uvm_pageout_start(1); uvm_pagedequeue(tpg); } } else { /* * ``page is not busy'' * implies that npages is 1 * and needs_clean is false. */ nextpg = TAILQ_NEXT(tpg, listq.queue); uvm_pagefree(tpg); if (pagedaemon) uvmexp.pdfreed++; } } } if (flags & (PGO_DEACTIVATE|PGO_FREE)) { mutex_exit(&uvm_pageqlock); } if (needs_clean) { modified = true; /* * start the i/o. if we're traversing by list, * keep our place in the list with a marker page. */ if (by_list) { TAILQ_INSERT_AFTER(&uobj->memq, pg, &curmp, listq.queue); } mutex_exit(slock); error = GOP_WRITE(vp, pgs, npages, flags); mutex_enter(slock); if (by_list) { pg = TAILQ_NEXT(&curmp, listq.queue); TAILQ_REMOVE(&uobj->memq, &curmp, listq.queue); } if (error) { break; } if (by_list) { continue; } } /* * find the next page and continue if there was no error. */ if (by_list) { if (nextpg) { pg = nextpg; nextpg = NULL; } else { pg = TAILQ_NEXT(pg, listq.queue); } } else { off += (npages - nback) << PAGE_SHIFT; if (off < endoff) { pg = uvm_pagelookup(uobj, off); } } } if (by_list) { TAILQ_REMOVE(&uobj->memq, &endmp, listq.queue); } if (modified && (vp->v_iflag & VI_WRMAPDIRTY) != 0 && (vp->v_type != VBLK || (vp->v_mount->mnt_flag & MNT_NODEVMTIME) == 0)) { GOP_MARKUPDATE(vp, GOP_UPDATE_MODIFIED); } /* * if we're cleaning and there was nothing to clean, * take us off the syncer list. if we started any i/o * and we're doing sync i/o, wait for all writes to finish. */ if (cleanall && wasclean && gp->g_dirtygen == dirtygen && (vp->v_iflag & VI_ONWORKLST) != 0) { #if defined(DEBUG) TAILQ_FOREACH(pg, &uobj->memq, listq.queue) { if ((pg->flags & (PG_FAKE | PG_MARKER)) != 0) { continue; } if ((pg->flags & PG_CLEAN) == 0) { printf("%s: %p: !CLEAN\n", __func__, pg); } if (pmap_is_modified(pg)) { printf("%s: %p: modified\n", __func__, pg); } } #endif /* defined(DEBUG) */ vp->v_iflag &= ~VI_WRMAPDIRTY; if (LIST_FIRST(&vp->v_dirtyblkhd) == NULL) vn_syncer_remove_from_worklist(vp); } #if !defined(DEBUG) skip_scan: #endif /* !defined(DEBUG) */ /* Wait for output to complete. */ if (!wasclean && !async && vp->v_numoutput != 0) { while (vp->v_numoutput != 0) cv_wait(&vp->v_cv, slock); } onworklst = (vp->v_iflag & VI_ONWORKLST) != 0; mutex_exit(slock); if ((flags & PGO_RECLAIM) != 0 && onworklst) { /* * in the case of PGO_RECLAIM, ensure to make the vnode clean. * retrying is not a big deal because, in many cases, * uobj->uo_npages is already 0 here. */ mutex_enter(slock); goto retry; } if (has_trans) { if (need_wapbl) WAPBL_END(vp->v_mount); fstrans_done(vp->v_mount); } return (error); } int genfs_gop_write(struct vnode *vp, struct vm_page **pgs, int npages, int flags) { off_t off; vaddr_t kva; size_t len; int error; UVMHIST_FUNC(__func__); UVMHIST_CALLED(ubchist); UVMHIST_LOG(ubchist, "vp %p pgs %p npages %d flags 0x%x", vp, pgs, npages, flags); off = pgs[0]->offset; kva = uvm_pagermapin(pgs, npages, UVMPAGER_MAPIN_WRITE | UVMPAGER_MAPIN_WAITOK); len = npages << PAGE_SHIFT; error = genfs_do_io(vp, off, kva, len, flags, UIO_WRITE, uvm_aio_biodone); return error; } int genfs_gop_write_rwmap(struct vnode *vp, struct vm_page **pgs, int npages, int flags) { off_t off; vaddr_t kva; size_t len; int error; UVMHIST_FUNC(__func__); UVMHIST_CALLED(ubchist); UVMHIST_LOG(ubchist, "vp %p pgs %p npages %d flags 0x%x", vp, pgs, npages, flags); off = pgs[0]->offset; kva = uvm_pagermapin(pgs, npages, UVMPAGER_MAPIN_READ | UVMPAGER_MAPIN_WAITOK); len = npages << PAGE_SHIFT; error = genfs_do_io(vp, off, kva, len, flags, UIO_WRITE, uvm_aio_biodone); return error; } /* * Backend routine for doing I/O to vnode pages. Pages are already locked * and mapped into kernel memory. Here we just look up the underlying * device block addresses and call the strategy routine. */ static int genfs_do_io(struct vnode *vp, off_t off, vaddr_t kva, size_t len, int flags, enum uio_rw rw, void (*iodone)(struct buf *)) { int s, error; int fs_bshift, dev_bshift; off_t eof, offset, startoffset; size_t bytes, iobytes, skipbytes; struct buf *mbp, *bp; const bool async = (flags & PGO_SYNCIO) == 0; const bool lazy = (flags & PGO_LAZY) == 0; const bool iowrite = rw == UIO_WRITE; const int brw = iowrite ? B_WRITE : B_READ; UVMHIST_FUNC(__func__); UVMHIST_CALLED(ubchist); UVMHIST_LOG(ubchist, "vp %p kva %p len 0x%x flags 0x%x", vp, kva, len, flags); KASSERT(vp->v_size <= vp->v_writesize); GOP_SIZE(vp, vp->v_writesize, &eof, 0); if (vp->v_type != VBLK) { fs_bshift = vp->v_mount->mnt_fs_bshift; dev_bshift = vp->v_mount->mnt_dev_bshift; } else { fs_bshift = DEV_BSHIFT; dev_bshift = DEV_BSHIFT; } error = 0; startoffset = off; bytes = MIN(len, eof - startoffset); skipbytes = 0; KASSERT(bytes != 0); if (iowrite) { mutex_enter(vp->v_interlock); vp->v_numoutput += 2; mutex_exit(vp->v_interlock); } mbp = getiobuf(vp, true); UVMHIST_LOG(ubchist, "vp %p mbp %p num now %d bytes 0x%x", vp, mbp, vp->v_numoutput, bytes); mbp->b_bufsize = len; mbp->b_data = (void *)kva; mbp->b_resid = mbp->b_bcount = bytes; mbp->b_cflags = BC_BUSY | BC_AGE; if (async) { mbp->b_flags = brw | B_ASYNC; mbp->b_iodone = iodone; } else { mbp->b_flags = brw; mbp->b_iodone = NULL; } if (curlwp == uvm.pagedaemon_lwp) BIO_SETPRIO(mbp, BPRIO_TIMELIMITED); else if (async || lazy) BIO_SETPRIO(mbp, BPRIO_TIMENONCRITICAL); else BIO_SETPRIO(mbp, BPRIO_TIMECRITICAL); bp = NULL; for (offset = startoffset; bytes > 0; offset += iobytes, bytes -= iobytes) { int run; daddr_t lbn, blkno; struct vnode *devvp; /* * bmap the file to find out the blkno to read from and * how much we can read in one i/o. if bmap returns an error, * skip the rest of the top-level i/o. */ lbn = offset >> fs_bshift; error = VOP_BMAP(vp, lbn, &devvp, &blkno, &run); if (error) { UVMHIST_LOG(ubchist, "VOP_BMAP lbn 0x%x -> %d\n", lbn,error,0,0); skipbytes += bytes; bytes = 0; goto loopdone; } /* * see how many pages can be read with this i/o. * reduce the i/o size if necessary to avoid * overwriting pages with valid data. */ iobytes = MIN((((off_t)lbn + 1 + run) << fs_bshift) - offset, bytes); /* * if this block isn't allocated, zero it instead of * reading it. unless we are going to allocate blocks, * mark the pages we zeroed PG_RDONLY. */ if (blkno == (daddr_t)-1) { if (!iowrite) { memset((char *)kva + (offset - startoffset), 0, iobytes); } skipbytes += iobytes; continue; } /* * allocate a sub-buf for this piece of the i/o * (or just use mbp if there's only 1 piece), * and start it going. */ if (offset == startoffset && iobytes == bytes) { bp = mbp; } else { UVMHIST_LOG(ubchist, "vp %p bp %p num now %d", vp, bp, vp->v_numoutput, 0); bp = getiobuf(vp, true); nestiobuf_setup(mbp, bp, offset - startoffset, iobytes); } bp->b_lblkno = 0; /* adjust physical blkno for partial blocks */ bp->b_blkno = blkno + ((offset - ((off_t)lbn << fs_bshift)) >> dev_bshift); UVMHIST_LOG(ubchist, "bp %p offset 0x%x bcount 0x%x blkno 0x%x", bp, offset, bp->b_bcount, bp->b_blkno); VOP_STRATEGY(devvp, bp); } loopdone: if (skipbytes) { UVMHIST_LOG(ubchist, "skipbytes %d", skipbytes, 0,0,0); } nestiobuf_done(mbp, skipbytes, error); if (async) { UVMHIST_LOG(ubchist, "returning 0 (async)", 0,0,0,0); return (0); } UVMHIST_LOG(ubchist, "waiting for mbp %p", mbp,0,0,0); error = biowait(mbp); s = splbio(); (*iodone)(mbp); splx(s); UVMHIST_LOG(ubchist, "returning, error %d", error,0,0,0); return (error); } int genfs_compat_getpages(void *v) { struct vop_getpages_args /* { struct vnode *a_vp; voff_t a_offset; struct vm_page **a_m; int *a_count; int a_centeridx; vm_prot_t a_access_type; int a_advice; int a_flags; } */ *ap = v; off_t origoffset; struct vnode *vp = ap->a_vp; struct uvm_object *uobj = &vp->v_uobj; struct vm_page *pg, **pgs; vaddr_t kva; int i, error, orignpages, npages; struct iovec iov; struct uio uio; kauth_cred_t cred = curlwp->l_cred; const bool memwrite = (ap->a_access_type & VM_PROT_WRITE) != 0; error = 0; origoffset = ap->a_offset; orignpages = *ap->a_count; pgs = ap->a_m; if (ap->a_flags & PGO_LOCKED) { uvn_findpages(uobj, origoffset, ap->a_count, ap->a_m, UFP_NOWAIT|UFP_NOALLOC| (memwrite ? UFP_NORDONLY : 0)); error = ap->a_m[ap->a_centeridx] == NULL ? EBUSY : 0; if (error == 0 && memwrite) { genfs_markdirty(vp); } return error; } if (origoffset + (ap->a_centeridx << PAGE_SHIFT) >= vp->v_size) { mutex_exit(uobj->vmobjlock); return EINVAL; } if ((ap->a_flags & PGO_SYNCIO) == 0) { mutex_exit(uobj->vmobjlock); return 0; } npages = orignpages; uvn_findpages(uobj, origoffset, &npages, pgs, UFP_ALL); mutex_exit(uobj->vmobjlock); kva = uvm_pagermapin(pgs, npages, UVMPAGER_MAPIN_READ | UVMPAGER_MAPIN_WAITOK); for (i = 0; i < npages; i++) { pg = pgs[i]; if ((pg->flags & PG_FAKE) == 0) { continue; } iov.iov_base = (char *)kva + (i << PAGE_SHIFT); iov.iov_len = PAGE_SIZE; uio.uio_iov = &iov; uio.uio_iovcnt = 1; uio.uio_offset = origoffset + (i << PAGE_SHIFT); uio.uio_rw = UIO_READ; uio.uio_resid = PAGE_SIZE; UIO_SETUP_SYSSPACE(&uio); /* XXX vn_lock */ error = VOP_READ(vp, &uio, 0, cred); if (error) { break; } if (uio.uio_resid) { memset(iov.iov_base, 0, uio.uio_resid); } } uvm_pagermapout(kva, npages); mutex_enter(uobj->vmobjlock); mutex_enter(&uvm_pageqlock); for (i = 0; i < npages; i++) { pg = pgs[i]; if (error && (pg->flags & PG_FAKE) != 0) { pg->flags |= PG_RELEASED; } else { pmap_clear_modify(pg); uvm_pageactivate(pg); } } if (error) { uvm_page_unbusy(pgs, npages); } mutex_exit(&uvm_pageqlock); if (error == 0 && memwrite) { genfs_markdirty(vp); } mutex_exit(uobj->vmobjlock); return error; } int genfs_compat_gop_write(struct vnode *vp, struct vm_page **pgs, int npages, int flags) { off_t offset; struct iovec iov; struct uio uio; kauth_cred_t cred = curlwp->l_cred; struct buf *bp; vaddr_t kva; int error; offset = pgs[0]->offset; kva = uvm_pagermapin(pgs, npages, UVMPAGER_MAPIN_WRITE | UVMPAGER_MAPIN_WAITOK); iov.iov_base = (void *)kva; iov.iov_len = npages << PAGE_SHIFT; uio.uio_iov = &iov; uio.uio_iovcnt = 1; uio.uio_offset = offset; uio.uio_rw = UIO_WRITE; uio.uio_resid = npages << PAGE_SHIFT; UIO_SETUP_SYSSPACE(&uio); /* XXX vn_lock */ error = VOP_WRITE(vp, &uio, 0, cred); mutex_enter(vp->v_interlock); vp->v_numoutput++; mutex_exit(vp->v_interlock); bp = getiobuf(vp, true); bp->b_cflags = BC_BUSY | BC_AGE; bp->b_lblkno = offset >> vp->v_mount->mnt_fs_bshift; bp->b_data = (char *)kva; bp->b_bcount = npages << PAGE_SHIFT; bp->b_bufsize = npages << PAGE_SHIFT; bp->b_resid = 0; bp->b_error = error; uvm_aio_aiodone(bp); return (error); } /* * Process a uio using direct I/O. If we reach a part of the request * which cannot be processed in this fashion for some reason, just return. * The caller must handle some additional part of the request using * buffered I/O before trying direct I/O again. */ void genfs_directio(struct vnode *vp, struct uio *uio, int ioflag) { struct vmspace *vs; struct iovec *iov; vaddr_t va; size_t len; const int mask = DEV_BSIZE - 1; int error; bool need_wapbl = (vp->v_mount && vp->v_mount->mnt_wapbl && (ioflag & IO_JOURNALLOCKED) == 0); /* * We only support direct I/O to user space for now. */ if (VMSPACE_IS_KERNEL_P(uio->uio_vmspace)) { return; } /* * If the vnode is mapped, we would need to get the getpages lock * to stabilize the bmap, but then we would get into trouble while * locking the pages if the pages belong to this same vnode (or a * multi-vnode cascade to the same effect). Just fall back to * buffered I/O if the vnode is mapped to avoid this mess. */ if (vp->v_vflag & VV_MAPPED) { return; } if (need_wapbl) { error = WAPBL_BEGIN(vp->v_mount); if (error) return; } /* * Do as much of the uio as possible with direct I/O. */ vs = uio->uio_vmspace; while (uio->uio_resid) { iov = uio->uio_iov; if (iov->iov_len == 0) { uio->uio_iov++; uio->uio_iovcnt--; continue; } va = (vaddr_t)iov->iov_base; len = MIN(iov->iov_len, genfs_maxdio); len &= ~mask; /* * If the next chunk is smaller than DEV_BSIZE or extends past * the current EOF, then fall back to buffered I/O. */ if (len == 0 || uio->uio_offset + len > vp->v_size) { break; } /* * Check alignment. The file offset must be at least * sector-aligned. The exact constraint on memory alignment * is very hardware-dependent, but requiring sector-aligned * addresses there too is safe. */ if (uio->uio_offset & mask || va & mask) { break; } error = genfs_do_directio(vs, va, len, vp, uio->uio_offset, uio->uio_rw); if (error) { break; } iov->iov_base = (char *)iov->iov_base + len; iov->iov_len -= len; uio->uio_offset += len; uio->uio_resid -= len; } if (need_wapbl) WAPBL_END(vp->v_mount); } /* * Iodone routine for direct I/O. We don't do much here since the request is * always synchronous, so the caller will do most of the work after biowait(). */ static void genfs_dio_iodone(struct buf *bp) { KASSERT((bp->b_flags & B_ASYNC) == 0); if ((bp->b_flags & B_READ) == 0 && (bp->b_cflags & BC_AGE) != 0) { mutex_enter(bp->b_objlock); vwakeup(bp); mutex_exit(bp->b_objlock); } putiobuf(bp); } /* * Process one chunk of a direct I/O request. */ static int genfs_do_directio(struct vmspace *vs, vaddr_t uva, size_t len, struct vnode *vp, off_t off, enum uio_rw rw) { struct vm_map *map; struct pmap *upm, *kpm __unused; size_t klen = round_page(uva + len) - trunc_page(uva); off_t spoff, epoff; vaddr_t kva, puva; paddr_t pa; vm_prot_t prot; int error, rv __diagused, poff, koff; const int pgoflags = PGO_CLEANIT | PGO_SYNCIO | PGO_JOURNALLOCKED | (rw == UIO_WRITE ? PGO_FREE : 0); /* * For writes, verify that this range of the file already has fully * allocated backing store. If there are any holes, just punt and * make the caller take the buffered write path. */ if (rw == UIO_WRITE) { daddr_t lbn, elbn, blkno; int bsize, bshift, run; bshift = vp->v_mount->mnt_fs_bshift; bsize = 1 << bshift; lbn = off >> bshift; elbn = (off + len + bsize - 1) >> bshift; while (lbn < elbn) { error = VOP_BMAP(vp, lbn, NULL, &blkno, &run); if (error) { return error; } if (blkno == (daddr_t)-1) { return ENOSPC; } lbn += 1 + run; } } /* * Flush any cached pages for parts of the file that we're about to * access. If we're writing, invalidate pages as well. */ spoff = trunc_page(off); epoff = round_page(off + len); mutex_enter(vp->v_interlock); error = VOP_PUTPAGES(vp, spoff, epoff, pgoflags); if (error) { return error; } /* * Wire the user pages and remap them into kernel memory. */ prot = rw == UIO_READ ? VM_PROT_READ | VM_PROT_WRITE : VM_PROT_READ; error = uvm_vslock(vs, (void *)uva, len, prot); if (error) { return error; } map = &vs->vm_map; upm = vm_map_pmap(map); kpm = vm_map_pmap(kernel_map); puva = trunc_page(uva); kva = uvm_km_alloc(kernel_map, klen, atop(puva) & uvmexp.colormask, UVM_KMF_VAONLY | UVM_KMF_WAITVA | UVM_KMF_COLORMATCH); for (poff = 0; poff < klen; poff += PAGE_SIZE) { rv = pmap_extract(upm, puva + poff, &pa); KASSERT(rv); pmap_kenter_pa(kva + poff, pa, prot, PMAP_WIRED); } pmap_update(kpm); /* * Do the I/O. */ koff = uva - trunc_page(uva); error = genfs_do_io(vp, off, kva + koff, len, PGO_SYNCIO, rw, genfs_dio_iodone); /* * Tear down the kernel mapping. */ pmap_kremove(kva, klen); pmap_update(kpm); uvm_km_free(kernel_map, kva, klen, UVM_KMF_VAONLY); /* * Unwire the user pages. */ uvm_vsunlock(vs, (void *)uva, len); return error; }