static int
zvol_write(struct bio *bio)
{
zvol_state_t *zv = bio->bi_bdev->bd_disk->private_data;
uint64_t offset = BIO_BI_SECTOR(bio) << 9;
uint64_t size = BIO_BI_SIZE(bio);
int error = 0;
dmu_tx_t *tx;
rl_t *rl;
uio_t uio;
if (bio->bi_rw & VDEV_REQ_FLUSH)
zil_commit(zv->zv_zilog, ZVOL_OBJ);
/*
* Some requests are just for flush and nothing else.
*/
if (size == 0)
goto out;
uio.uio_bvec = &bio->bi_io_vec[BIO_BI_IDX(bio)];
uio.uio_skip = BIO_BI_SKIP(bio);
uio.uio_resid = size;
uio.uio_iovcnt = bio->bi_vcnt - BIO_BI_IDX(bio);
uio.uio_loffset = offset;
uio.uio_limit = MAXOFFSET_T;
uio.uio_segflg = UIO_BVEC;
rl = zfs_range_lock(&zv->zv_znode, offset, size, RL_WRITER);
tx = dmu_tx_create(zv->zv_objset);
dmu_tx_hold_write(tx, ZVOL_OBJ, offset, size);
/* This will only fail for ENOSPC */
error = dmu_tx_assign(tx, TXG_WAIT);
if (error) {
dmu_tx_abort(tx);
zfs_range_unlock(rl);
goto out;
}
error = dmu_write_uio(zv->zv_objset, ZVOL_OBJ, &uio, size, tx);
if (error == 0)
zvol_log_write(zv, tx, offset, size,
!!(bio->bi_rw & VDEV_REQ_FUA));
dmu_tx_commit(tx);
zfs_range_unlock(rl);
if ((bio->bi_rw & VDEV_REQ_FUA) ||
zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS)
zil_commit(zv->zv_zilog, ZVOL_OBJ);
out:
return (error);
}
/*
* Common write path running under the zvol taskq context. This function
* is responsible for copying the request structure data in to the DMU and
* signaling the request queue with the result of the copy.
*/
static void
zvol_write(void *arg)
{
struct request *req = (struct request *)arg;
struct request_queue *q = req->q;
zvol_state_t *zv = q->queuedata;
fstrans_cookie_t cookie = spl_fstrans_mark();
uint64_t offset = blk_rq_pos(req) << 9;
uint64_t size = blk_rq_bytes(req);
int error = 0;
dmu_tx_t *tx;
rl_t *rl;
if (req->cmd_flags & VDEV_REQ_FLUSH)
zil_commit(zv->zv_zilog, ZVOL_OBJ);
/*
* Some requests are just for flush and nothing else.
*/
if (size == 0) {
error = 0;
goto out;
}
rl = zfs_range_lock(&zv->zv_znode, offset, size, RL_WRITER);
tx = dmu_tx_create(zv->zv_objset);
dmu_tx_hold_write(tx, ZVOL_OBJ, offset, size);
/* This will only fail for ENOSPC */
error = dmu_tx_assign(tx, TXG_WAIT);
if (error) {
dmu_tx_abort(tx);
zfs_range_unlock(rl);
goto out;
}
error = dmu_write_req(zv->zv_objset, ZVOL_OBJ, req, tx);
if (error == 0)
zvol_log_write(zv, tx, offset, size,
req->cmd_flags & VDEV_REQ_FUA);
dmu_tx_commit(tx);
zfs_range_unlock(rl);
if ((req->cmd_flags & VDEV_REQ_FUA) ||
zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS)
zil_commit(zv->zv_zilog, ZVOL_OBJ);
out:
blk_end_request(req, -error, size);
spl_fstrans_unmark(cookie);
}
static int
zvol_write(zvol_state_t *zv, uio_t *uio, boolean_t sync)
{
uint64_t volsize = zv->zv_volsize;
rl_t *rl;
int error = 0;
ASSERT(zv && zv->zv_open_count > 0);
rl = zfs_range_lock(&zv->zv_range_lock, uio->uio_loffset,
uio->uio_resid, RL_WRITER);
while (uio->uio_resid > 0 && uio->uio_loffset < volsize) {
uint64_t bytes = MIN(uio->uio_resid, DMU_MAX_ACCESS >> 1);
uint64_t off = uio->uio_loffset;
dmu_tx_t *tx = dmu_tx_create(zv->zv_objset);
if (bytes > volsize - off) /* don't write past the end */
bytes = volsize - off;
dmu_tx_hold_write(tx, ZVOL_OBJ, off, bytes);
/* This will only fail for ENOSPC */
error = dmu_tx_assign(tx, TXG_WAIT);
if (error) {
dmu_tx_abort(tx);
break;
}
error = dmu_write_uio_dbuf(zv->zv_dbuf, uio, bytes, tx);
if (error == 0)
zvol_log_write(zv, tx, off, bytes, sync);
dmu_tx_commit(tx);
if (error)
break;
}
zfs_range_unlock(rl);
if (sync)
zil_commit(zv->zv_zilog, ZVOL_OBJ);
return (error);
}
/*
* Common write path running under the zvol taskq context. This function
* is responsible for copying the request structure data in to the DMU and
* signaling the request queue with the result of the copy.
*/
static void
zvol_write(void *arg)
{
struct request *req = (struct request *)arg;
struct request_queue *q = req->q;
zvol_state_t *zv = q->queuedata;
uint64_t offset = blk_rq_pos(req) << 9;
uint64_t size = blk_rq_bytes(req);
int error = 0;
dmu_tx_t *tx;
rl_t *rl;
rl = zfs_range_lock(&zv->zv_znode, offset, size, RL_WRITER);
tx = dmu_tx_create(zv->zv_objset);
dmu_tx_hold_write(tx, ZVOL_OBJ, offset, size);
/* This will only fail for ENOSPC */
error = dmu_tx_assign(tx, TXG_WAIT);
if (error) {
dmu_tx_abort(tx);
zfs_range_unlock(rl);
blk_end_request(req, -error, size);
return;
}
error = dmu_write_req(zv->zv_objset, ZVOL_OBJ, req, tx);
if (error == 0)
zvol_log_write(zv, tx, offset, size, rq_is_sync(req));
dmu_tx_commit(tx);
zfs_range_unlock(rl);
if (rq_is_sync(req))
zil_commit(zv->zv_zilog, ZVOL_OBJ);
blk_end_request(req, -error, size);
}
/*
* Common write path running under the zvol taskq context. This function
* is responsible for copying the request structure data in to the DMU and
* signaling the request queue with the result of the copy.
*/
static void
zvol_write(void *arg)
{
struct request *req = (struct request *)arg;
struct request_queue *q = req->q;
zvol_state_t *zv = q->queuedata;
uint64_t offset = blk_rq_pos(req) << 9;
uint64_t size = blk_rq_bytes(req);
int error = 0;
dmu_tx_t *tx;
rl_t *rl;
/*
* Annotate this call path with a flag that indicates that it is
* unsafe to use KM_SLEEP during memory allocations due to the
* potential for a deadlock. KM_PUSHPAGE should be used instead.
*/
ASSERT(!(current->flags & PF_NOFS));
current->flags |= PF_NOFS;
if (req->cmd_flags & VDEV_REQ_FLUSH)
zil_commit(zv->zv_zilog, ZVOL_OBJ);
/*
* Some requests are just for flush and nothing else.
*/
if (size == 0) {
blk_end_request(req, 0, size);
goto out;
}
rl = zfs_range_lock(&zv->zv_znode, offset, size, RL_WRITER);
tx = dmu_tx_create(zv->zv_objset);
dmu_tx_hold_write(tx, ZVOL_OBJ, offset, size);
/* This will only fail for ENOSPC */
error = dmu_tx_assign(tx, TXG_WAIT);
if (error) {
dmu_tx_abort(tx);
zfs_range_unlock(rl);
blk_end_request(req, -error, size);
goto out;
}
error = dmu_write_req(zv->zv_objset, ZVOL_OBJ, req, tx);
if (error == 0)
zvol_log_write(zv, tx, offset, size,
req->cmd_flags & VDEV_REQ_FUA);
dmu_tx_commit(tx);
zfs_range_unlock(rl);
if ((req->cmd_flags & VDEV_REQ_FUA) ||
zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS)
zil_commit(zv->zv_zilog, ZVOL_OBJ);
blk_end_request(req, -error, size);
out:
current->flags &= ~PF_NOFS;
}
int
zvol_strategy(buf_t *bp)
{
zvol_state_t *zv = ddi_get_soft_state(zvol_state, getminor(bp->b_edev));
uint64_t off, volsize;
size_t size, resid;
char *addr;
objset_t *os;
int error = 0;
int sync;
int reading;
int txg_sync_needed = B_FALSE;
if (zv == NULL) {
bioerror(bp, ENXIO);
biodone(bp);
return (0);
}
if (getminor(bp->b_edev) == 0) {
bioerror(bp, EINVAL);
biodone(bp);
return (0);
}
if (zv->zv_readonly && !(bp->b_flags & B_READ)) {
bioerror(bp, EROFS);
biodone(bp);
return (0);
}
off = ldbtob(bp->b_blkno);
volsize = zv->zv_volsize;
os = zv->zv_objset;
ASSERT(os != NULL);
sync = !(bp->b_flags & B_ASYNC) && !(zil_disable);
bp_mapin(bp);
addr = bp->b_un.b_addr;
resid = bp->b_bcount;
/*
* There must be no buffer changes when doing a dmu_sync() because
* we can't change the data whilst calculating the checksum.
* A better approach than a per zvol rwlock would be to lock ranges.
*/
reading = bp->b_flags & B_READ;
if (reading || resid <= zvol_immediate_write_sz)
rw_enter(&zv->zv_dslock, RW_READER);
else
rw_enter(&zv->zv_dslock, RW_WRITER);
while (resid != 0 && off < volsize) {
size = MIN(resid, 1UL << 20); /* cap at 1MB per tx */
if (size > volsize - off) /* don't write past the end */
size = volsize - off;
if (reading) {
error = dmu_read(os, ZVOL_OBJ, off, size, addr);
} else {
dmu_tx_t *tx = dmu_tx_create(os);
dmu_tx_hold_write(tx, ZVOL_OBJ, off, size);
error = dmu_tx_assign(tx, TXG_WAIT);
if (error) {
dmu_tx_abort(tx);
} else {
dmu_write(os, ZVOL_OBJ, off, size, addr, tx);
if (sync) {
/* use the ZIL to commit this write */
if (zvol_log_write(zv, tx, off, size,
addr) != 0) {
txg_sync_needed = B_TRUE;
}
}
dmu_tx_commit(tx);
}
}
if (error)
break;
off += size;
addr += size;
resid -= size;
}
rw_exit(&zv->zv_dslock);
if ((bp->b_resid = resid) == bp->b_bcount)
bioerror(bp, off > volsize ? EINVAL : error);
biodone(bp);
if (sync) {
if (txg_sync_needed)
txg_wait_synced(dmu_objset_pool(os), 0);
else
zil_commit(zv->zv_zilog, UINT64_MAX, 0);
}
return (0);
}
