zfs-builds-mm/zfs-2.0.0/module/os/freebsd/zfs/dmu_os.c
2020-12-02 17:25:31 +01:00

349 lines
8.8 KiB
C

/*
* Copyright (c) 2020 iXsystems, Inc.
* 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 AUTHORS 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 AUTHORS 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 <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/param.h>
#include <sys/dmu.h>
#include <sys/dmu_impl.h>
#include <sys/dmu_tx.h>
#include <sys/dbuf.h>
#include <sys/dnode.h>
#include <sys/zfs_context.h>
#include <sys/dmu_objset.h>
#include <sys/dmu_traverse.h>
#include <sys/dsl_dataset.h>
#include <sys/dsl_dir.h>
#include <sys/dsl_pool.h>
#include <sys/dsl_synctask.h>
#include <sys/dsl_prop.h>
#include <sys/dmu_zfetch.h>
#include <sys/zfs_ioctl.h>
#include <sys/zap.h>
#include <sys/zio_checksum.h>
#include <sys/zio_compress.h>
#include <sys/sa.h>
#include <sys/zfeature.h>
#include <sys/abd.h>
#include <sys/zfs_rlock.h>
#include <sys/racct.h>
#include <sys/vm.h>
#include <sys/zfs_znode.h>
#include <sys/zfs_vnops.h>
#include <sys/ccompat.h>
#ifndef IDX_TO_OFF
#define IDX_TO_OFF(idx) (((vm_ooffset_t)(idx)) << PAGE_SHIFT)
#endif
#if __FreeBSD_version < 1300051
#define VM_ALLOC_BUSY_FLAGS VM_ALLOC_NOBUSY
#else
#define VM_ALLOC_BUSY_FLAGS VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY
#endif
#if __FreeBSD_version < 1300072
#define dmu_page_lock(m) vm_page_lock(m)
#define dmu_page_unlock(m) vm_page_unlock(m)
#else
#define dmu_page_lock(m)
#define dmu_page_unlock(m)
#endif
static int
dmu_buf_hold_array(objset_t *os, uint64_t object, uint64_t offset,
uint64_t length, int read, void *tag, int *numbufsp, dmu_buf_t ***dbpp)
{
dnode_t *dn;
int err;
err = dnode_hold(os, object, FTAG, &dn);
if (err)
return (err);
err = dmu_buf_hold_array_by_dnode(dn, offset, length, read, tag,
numbufsp, dbpp, DMU_READ_PREFETCH);
dnode_rele(dn, FTAG);
return (err);
}
int
dmu_write_pages(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
vm_page_t *ma, dmu_tx_t *tx)
{
dmu_buf_t **dbp;
struct sf_buf *sf;
int numbufs, i;
int err;
if (size == 0)
return (0);
err = dmu_buf_hold_array(os, object, offset, size,
FALSE, FTAG, &numbufs, &dbp);
if (err)
return (err);
for (i = 0; i < numbufs; i++) {
int tocpy, copied, thiscpy;
int bufoff;
dmu_buf_t *db = dbp[i];
caddr_t va;
ASSERT(size > 0);
ASSERT3U(db->db_size, >=, PAGESIZE);
bufoff = offset - db->db_offset;
tocpy = (int)MIN(db->db_size - bufoff, size);
ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
if (tocpy == db->db_size)
dmu_buf_will_fill(db, tx);
else
dmu_buf_will_dirty(db, tx);
for (copied = 0; copied < tocpy; copied += PAGESIZE) {
ASSERT3U(ptoa((*ma)->pindex), ==,
db->db_offset + bufoff);
thiscpy = MIN(PAGESIZE, tocpy - copied);
va = zfs_map_page(*ma, &sf);
bcopy(va, (char *)db->db_data + bufoff, thiscpy);
zfs_unmap_page(sf);
ma += 1;
bufoff += PAGESIZE;
}
if (tocpy == db->db_size)
dmu_buf_fill_done(db, tx);
offset += tocpy;
size -= tocpy;
}
dmu_buf_rele_array(dbp, numbufs, FTAG);
return (err);
}
int
dmu_read_pages(objset_t *os, uint64_t object, vm_page_t *ma, int count,
int *rbehind, int *rahead, int last_size)
{
struct sf_buf *sf;
vm_object_t vmobj;
vm_page_t m;
dmu_buf_t **dbp;
dmu_buf_t *db;
caddr_t va;
int numbufs, i;
int bufoff, pgoff, tocpy;
int mi, di;
int err;
ASSERT3U(ma[0]->pindex + count - 1, ==, ma[count - 1]->pindex);
ASSERT(last_size <= PAGE_SIZE);
err = dmu_buf_hold_array(os, object, IDX_TO_OFF(ma[0]->pindex),
IDX_TO_OFF(count - 1) + last_size, TRUE, FTAG, &numbufs, &dbp);
if (err != 0)
return (err);
#ifdef ZFS_DEBUG
IMPLY(last_size < PAGE_SIZE, *rahead == 0);
if (dbp[0]->db_offset != 0 || numbufs > 1) {
for (i = 0; i < numbufs; i++) {
ASSERT(ISP2(dbp[i]->db_size));
ASSERT((dbp[i]->db_offset % dbp[i]->db_size) == 0);
ASSERT3U(dbp[i]->db_size, ==, dbp[0]->db_size);
}
}
#endif
vmobj = ma[0]->object;
zfs_vmobject_wlock_12(vmobj);
db = dbp[0];
for (i = 0; i < *rbehind; i++) {
m = vm_page_grab_unlocked(vmobj, ma[0]->pindex - 1 - i,
VM_ALLOC_NORMAL | VM_ALLOC_NOWAIT | VM_ALLOC_BUSY_FLAGS);
if (m == NULL)
break;
if (!vm_page_none_valid(m)) {
ASSERT3U(m->valid, ==, VM_PAGE_BITS_ALL);
vm_page_do_sunbusy(m);
break;
}
ASSERT(m->dirty == 0);
ASSERT(!pmap_page_is_write_mapped(m));
ASSERT(db->db_size > PAGE_SIZE);
bufoff = IDX_TO_OFF(m->pindex) % db->db_size;
va = zfs_map_page(m, &sf);
bcopy((char *)db->db_data + bufoff, va, PAGESIZE);
zfs_unmap_page(sf);
vm_page_valid(m);
dmu_page_lock(m);
if ((m->busy_lock & VPB_BIT_WAITERS) != 0)
vm_page_activate(m);
else
vm_page_deactivate(m);
dmu_page_unlock(m);
vm_page_do_sunbusy(m);
}
*rbehind = i;
bufoff = IDX_TO_OFF(ma[0]->pindex) % db->db_size;
pgoff = 0;
for (mi = 0, di = 0; mi < count && di < numbufs; ) {
if (pgoff == 0) {
m = ma[mi];
if (m != bogus_page) {
vm_page_assert_xbusied(m);
ASSERT(vm_page_none_valid(m));
ASSERT(m->dirty == 0);
ASSERT(!pmap_page_is_write_mapped(m));
va = zfs_map_page(m, &sf);
}
}
if (bufoff == 0)
db = dbp[di];
if (m != bogus_page) {
ASSERT3U(IDX_TO_OFF(m->pindex) + pgoff, ==,
db->db_offset + bufoff);
}
/*
* We do not need to clamp the copy size by the file
* size as the last block is zero-filled beyond the
* end of file anyway.
*/
tocpy = MIN(db->db_size - bufoff, PAGESIZE - pgoff);
if (m != bogus_page)
bcopy((char *)db->db_data + bufoff, va + pgoff, tocpy);
pgoff += tocpy;
ASSERT(pgoff <= PAGESIZE);
if (pgoff == PAGESIZE) {
if (m != bogus_page) {
zfs_unmap_page(sf);
vm_page_valid(m);
}
ASSERT(mi < count);
mi++;
pgoff = 0;
}
bufoff += tocpy;
ASSERT(bufoff <= db->db_size);
if (bufoff == db->db_size) {
ASSERT(di < numbufs);
di++;
bufoff = 0;
}
}
#ifdef ZFS_DEBUG
/*
* Three possibilities:
* - last requested page ends at a buffer boundary and , thus,
* all pages and buffers have been iterated;
* - all requested pages are filled, but the last buffer
* has not been exhausted;
* the read-ahead is possible only in this case;
* - all buffers have been read, but the last page has not been
* fully filled;
* this is only possible if the file has only a single buffer
* with a size that is not a multiple of the page size.
*/
if (mi == count) {
ASSERT(di >= numbufs - 1);
IMPLY(*rahead != 0, di == numbufs - 1);
IMPLY(*rahead != 0, bufoff != 0);
ASSERT(pgoff == 0);
}
if (di == numbufs) {
ASSERT(mi >= count - 1);
ASSERT(*rahead == 0);
IMPLY(pgoff == 0, mi == count);
if (pgoff != 0) {
ASSERT(mi == count - 1);
ASSERT((dbp[0]->db_size & PAGE_MASK) != 0);
}
}
#endif
if (pgoff != 0) {
ASSERT(m != bogus_page);
bzero(va + pgoff, PAGESIZE - pgoff);
zfs_unmap_page(sf);
vm_page_valid(m);
}
for (i = 0; i < *rahead; i++) {
m = vm_page_grab_unlocked(vmobj, ma[count - 1]->pindex + 1 + i,
VM_ALLOC_NORMAL | VM_ALLOC_NOWAIT | VM_ALLOC_BUSY_FLAGS);
if (m == NULL)
break;
if (!vm_page_none_valid(m)) {
ASSERT3U(m->valid, ==, VM_PAGE_BITS_ALL);
vm_page_do_sunbusy(m);
break;
}
ASSERT(m->dirty == 0);
ASSERT(!pmap_page_is_mapped(m));
ASSERT(db->db_size > PAGE_SIZE);
bufoff = IDX_TO_OFF(m->pindex) % db->db_size;
tocpy = MIN(db->db_size - bufoff, PAGESIZE);
va = zfs_map_page(m, &sf);
bcopy((char *)db->db_data + bufoff, va, tocpy);
if (tocpy < PAGESIZE) {
ASSERT(i == *rahead - 1);
ASSERT((db->db_size & PAGE_MASK) != 0);
bzero(va + tocpy, PAGESIZE - tocpy);
}
zfs_unmap_page(sf);
vm_page_valid(m);
dmu_page_lock(m);
if ((m->busy_lock & VPB_BIT_WAITERS) != 0)
vm_page_activate(m);
else
vm_page_deactivate(m);
dmu_page_unlock(m);
vm_page_do_sunbusy(m);
}
*rahead = i;
zfs_vmobject_wunlock_12(vmobj);
dmu_buf_rele_array(dbp, numbufs, FTAG);
return (0);
}