static int
vdev_disk_io_start(zio_t *zio)
{
vdev_t *vd = zio->io_vd;
vdev_disk_t *dvd = vd->vdev_tsd;
struct buf *bp;
vfs_context_t context;
int flags, error = 0;
if (zio->io_type == ZIO_TYPE_IOCTL) {
zio_vdev_io_bypass(zio);
/* XXPOLICY */
if (vdev_is_dead(vd)) {
zio->io_error = ENXIO;
//zio_next_stage_async(zio);
return (ZIO_PIPELINE_CONTINUE);
//return;
}
switch (zio->io_cmd) {
case DKIOCFLUSHWRITECACHE:
if (zfs_nocacheflush)
break;
if (vd->vdev_nowritecache) {
zio->io_error = SET_ERROR(ENOTSUP);
break;
}
context = vfs_context_create((vfs_context_t)0);
error = VNOP_IOCTL(dvd->vd_devvp, DKIOCSYNCHRONIZECACHE, NULL, FWRITE, context);
(void) vfs_context_rele(context);
if (error == 0)
vdev_disk_ioctl_done(zio, error);
else
error = ENOTSUP;
if (error == 0) {
/*
* The ioctl will be done asychronously,
* and will call vdev_disk_ioctl_done()
* upon completion.
*/
return ZIO_PIPELINE_STOP;
} else if (error == ENOTSUP || error == ENOTTY) {
/*
* If we get ENOTSUP or ENOTTY, we know that
* no future attempts will ever succeed.
* In this case we set a persistent bit so
* that we don't bother with the ioctl in the
* future.
*/
vd->vdev_nowritecache = B_TRUE;
}
zio->io_error = error;
break;
default:
zio->io_error = SET_ERROR(ENOTSUP);
}
//zio_next_stage_async(zio);
return (ZIO_PIPELINE_CONTINUE);
}
if (zio->io_type == ZIO_TYPE_READ && vdev_cache_read(zio) == 0)
return (ZIO_PIPELINE_STOP);
// return;
if ((zio = vdev_queue_io(zio)) == NULL)
return (ZIO_PIPELINE_CONTINUE);
// return;
flags = (zio->io_type == ZIO_TYPE_READ ? B_READ : B_WRITE);
//flags |= B_NOCACHE;
if (zio->io_flags & ZIO_FLAG_FAILFAST)
flags |= B_FAILFAST;
/*
* Check the state of this device to see if it has been offlined or
* is in an error state. If the device was offlined or closed,
* dvd will be NULL and buf_alloc below will fail
*/
//error = vdev_is_dead(vd) ? ENXIO : vdev_error_inject(vd, zio);
if (vdev_is_dead(vd)) {
error = ENXIO;
}
if (error) {
zio->io_error = error;
//zio_next_stage_async(zio);
return (ZIO_PIPELINE_CONTINUE);
}
bp = buf_alloc(dvd->vd_devvp);
ASSERT(bp != NULL);
ASSERT(zio->io_data != NULL);
ASSERT(zio->io_size != 0);
buf_setflags(bp, flags);
buf_setcount(bp, zio->io_size);
buf_setdataptr(bp, (uintptr_t)zio->io_data);
if (dvd->vd_ashift) {
buf_setlblkno(bp, zio->io_offset>>dvd->vd_ashift);
buf_setblkno(bp, zio->io_offset>>dvd->vd_ashift);
} else {
static void
vdev_disk_io_start(zio_t *zio)
{
vdev_t *vd = zio->io_vd;
vdev_disk_t *dvd = vd->vdev_tsd;
struct buf *bp;
vfs_context_t context;
int flags, error = 0;
/*
* If the vdev is closed, it's likely in the REMOVED or FAULTED state.
* Nothing to be done here but return failure.
*/
if (dvd == NULL || (dvd->vd_offline) || dvd->vd_devvp == NULL) {
zio->io_error = ENXIO;
zio_interrupt(zio);
return;
}
switch (zio->io_type) {
case ZIO_TYPE_IOCTL:
if (!vdev_readable(vd)) {
zio->io_error = SET_ERROR(ENXIO);
zio_interrupt(zio);
return;
}
switch (zio->io_cmd) {
case DKIOCFLUSHWRITECACHE:
if (zfs_nocacheflush)
break;
if (vd->vdev_nowritecache) {
zio->io_error = SET_ERROR(ENOTSUP);
break;
}
context = vfs_context_create(spl_vfs_context_kernel());
error = VNOP_IOCTL(dvd->vd_devvp, DKIOCSYNCHRONIZECACHE,
NULL, FWRITE, context);
(void) vfs_context_rele(context);
if (error == 0)
vdev_disk_ioctl_done(zio, error);
else
error = ENOTSUP;
if (error == 0) {
/*
* The ioctl will be done asychronously,
* and will call vdev_disk_ioctl_done()
* upon completion.
*/
return;
} else if (error == ENOTSUP || error == ENOTTY) {
/*
* If we get ENOTSUP or ENOTTY, we know that
* no future attempts will ever succeed.
* In this case we set a persistent bit so
* that we don't bother with the ioctl in the
* future.
*/
vd->vdev_nowritecache = B_TRUE;
}
zio->io_error = error;
break;
default:
zio->io_error = SET_ERROR(ENOTSUP);
} /* io_cmd */
zio_execute(zio);
return;
case ZIO_TYPE_WRITE:
if (zio->io_priority == ZIO_PRIORITY_SYNC_WRITE)
flags = B_WRITE;
else
flags = B_WRITE | B_ASYNC;
break;
case ZIO_TYPE_READ:
if (zio->io_priority == ZIO_PRIORITY_SYNC_READ)
flags = B_READ;
else
flags = B_READ | B_ASYNC;
break;
default:
zio->io_error = SET_ERROR(ENOTSUP);
zio_interrupt(zio);
return;
} /* io_type */
ASSERT(zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE);
/* Stop OSX from also caching our data */
flags |= B_NOCACHE;
if (zio->io_flags & ZIO_FLAG_FAILFAST)
flags |= B_FAILFAST;
zio->io_target_timestamp = zio_handle_io_delay(zio);
bp = buf_alloc(dvd->vd_devvp);
ASSERT(bp != NULL);
ASSERT(zio->io_data != NULL);
ASSERT(zio->io_size != 0);
buf_setflags(bp, flags);
buf_setcount(bp, zio->io_size);
buf_setdataptr(bp, (uintptr_t)zio->io_data);
/*
* Map offset to blcknumber, based on physical block number.
* (512, 4096, ..). If we fail to map, default back to
* standard 512. lbtodb() is fixed at 512.
*/
buf_setblkno(bp, zio->io_offset >> dvd->vd_ashift);
buf_setlblkno(bp, zio->io_offset >> dvd->vd_ashift);
buf_setsize(bp, zio->io_size);
if (buf_setcallback(bp, vdev_disk_io_intr, zio) != 0)
panic("vdev_disk_io_start: buf_setcallback failed\n");
if (zio->io_type == ZIO_TYPE_WRITE) {
vnode_startwrite(dvd->vd_devvp);
}
error = VNOP_STRATEGY(bp);
ASSERT(error == 0);
if (error) {
zio->io_error = error;
zio_interrupt(zio);
return;
}
}
int
physio( void (*f_strategy)(buf_t),
buf_t bp,
dev_t dev,
int flags,
u_int (*f_minphys)(buf_t),
struct uio *uio,
int blocksize)
{
struct proc *p = current_proc();
int error, i, buf_allocated, todo, iosize;
int orig_bflags = 0;
int64_t done;
error = 0;
flags &= B_READ | B_WRITE;
buf_allocated = 0;
/*
* [check user read/write access to the data buffer]
*
* Check each iov one by one. Note that we know if we're reading or
* writing, so we ignore the uio's rw parameter. Also note that if
* we're doing a read, that's a *write* to user-space.
*/
for (i = 0; i < uio->uio_iovcnt; i++) {
if (UIO_SEG_IS_USER_SPACE(uio->uio_segflg)) {
user_addr_t base;
user_size_t len;
if (uio_getiov(uio, i, &base, &len) ||
!useracc(base,
len,
(flags == B_READ) ? B_WRITE : B_READ))
return (EFAULT);
}
}
/*
* Make sure we have a buffer, creating one if necessary.
*/
if (bp == NULL) {
bp = buf_alloc((vnode_t)0);
buf_allocated = 1;
} else
orig_bflags = buf_flags(bp);
/*
* at this point we should have a buffer
* that is marked BL_BUSY... we either
* acquired it via buf_alloc, or it was
* passed into us... if it was passed
* in, it needs to already be owned by
* the caller (i.e. BL_BUSY is set)
*/
assert(bp->b_lflags & BL_BUSY);
/*
* [set up the fixed part of the buffer for a transfer]
*/
bp->b_dev = dev;
bp->b_proc = p;
/*
* [mark the buffer busy for physical I/O]
* (i.e. set B_PHYS (because it's an I/O to user
* memory, and B_RAW, because B_RAW is to be
* "Set by physio for raw transfers.", in addition
* to the read/write flag.)
*/
buf_setflags(bp, B_PHYS | B_RAW);
/*
* [while there is data to transfer and no I/O error]
* Note that I/O errors are handled with a 'goto' at the bottom
* of the 'while' loop.
*/
while (uio_resid(uio) > 0) {
if ( (iosize = uio_curriovlen(uio)) > MAXPHYSIO_WIRED)
iosize = MAXPHYSIO_WIRED;
/*
* make sure we're set to issue a fresh I/O
* in the right direction
*/
buf_reset(bp, flags);
/* [set up the buffer for a maximum-sized transfer] */
buf_setblkno(bp, uio_offset(uio) / blocksize);
buf_setcount(bp, iosize);
buf_setdataptr(bp, (uintptr_t)CAST_DOWN(caddr_t, uio_curriovbase(uio)));
/*
* [call f_minphys to bound the tranfer size]
* and remember the amount of data to transfer,
* for later comparison.
*/
(*f_minphys)(bp);
todo = buf_count(bp);
/*
* [lock the part of the user address space involved
* in the transfer]
*/
if(UIO_SEG_IS_USER_SPACE(uio->uio_segflg)) {
error = vslock(CAST_USER_ADDR_T(buf_dataptr(bp)),
(user_size_t)todo);
if (error)
goto done;
}
/* [call f_strategy to start the transfer] */
(*f_strategy)(bp);
/* [wait for the transfer to complete] */
error = (int)buf_biowait(bp);
/*
* [unlock the part of the address space previously
* locked]
*/
if(UIO_SEG_IS_USER_SPACE(uio->uio_segflg))
vsunlock(CAST_USER_ADDR_T(buf_dataptr(bp)),
(user_size_t)todo,
(flags & B_READ));
/*
* [deduct the transfer size from the total number
* of data to transfer]
*/
done = buf_count(bp) - buf_resid(bp);
uio_update(uio, done);
/*
* Now, check for an error.
* Also, handle weird end-of-disk semantics.
*/
if (error || done < todo)
goto done;
}
done:
if (buf_allocated)
buf_free(bp);
else
buf_setflags(bp, orig_bflags);
return (error);
}
