static int
tmpfs_read (struct vop_read_args *ap)
{
struct buf *bp;
struct vnode *vp = ap->a_vp;
struct uio *uio = ap->a_uio;
struct tmpfs_node *node;
off_t base_offset;
size_t offset;
size_t len;
size_t resid;
int error;
/*
* Check the basics
*/
if (uio->uio_offset < 0)
return (EINVAL);
if (vp->v_type != VREG)
return (EINVAL);
/*
* Extract node, try to shortcut the operation through
* the VM page cache, allowing us to avoid buffer cache
* overheads.
*/
node = VP_TO_TMPFS_NODE(vp);
resid = uio->uio_resid;
error = vop_helper_read_shortcut(ap);
if (error)
return error;
if (uio->uio_resid == 0) {
if (resid)
goto finished;
return error;
}
/*
* Fall-through to our normal read code.
*/
while (uio->uio_resid > 0 && uio->uio_offset < node->tn_size) {
/*
* Use buffer cache I/O (via tmpfs_strategy)
*/
offset = (size_t)uio->uio_offset & TMPFS_BLKMASK64;
base_offset = (off_t)uio->uio_offset - offset;
bp = getcacheblk(vp, base_offset, TMPFS_BLKSIZE, 0);
if (bp == NULL) {
error = bread(vp, base_offset, TMPFS_BLKSIZE, &bp);
if (error) {
brelse(bp);
kprintf("tmpfs_read bread error %d\n", error);
break;
}
/*
* tmpfs pretty much fiddles directly with the VM
* system, don't let it exhaust it or we won't play
* nice with other processes.
*
* Only do this if the VOP is coming from a normal
* read/write. The VM system handles the case for
* UIO_NOCOPY.
*/
if (uio->uio_segflg != UIO_NOCOPY)
vm_wait_nominal();
}
bp->b_flags |= B_CLUSTEROK;
/*
* Figure out how many bytes we can actually copy this loop.
*/
len = TMPFS_BLKSIZE - offset;
if (len > uio->uio_resid)
len = uio->uio_resid;
if (len > node->tn_size - uio->uio_offset)
len = (size_t)(node->tn_size - uio->uio_offset);
error = uiomovebp(bp, (char *)bp->b_data + offset, len, uio);
bqrelse(bp);
if (error) {
kprintf("tmpfs_read uiomove error %d\n", error);
break;
}
}
finished:
if ((node->tn_status & TMPFS_NODE_ACCESSED) == 0) {
TMPFS_NODE_LOCK(node);
node->tn_status |= TMPFS_NODE_ACCESSED;
TMPFS_NODE_UNLOCK(node);
}
return (error);
}
static int
tmpfs_read (struct vop_read_args *ap)
{
struct buf *bp;
struct vnode *vp = ap->a_vp;
struct uio *uio = ap->a_uio;
struct tmpfs_node *node;
off_t base_offset;
size_t offset;
size_t len;
int error;
error = 0;
if (uio->uio_resid == 0) {
return error;
}
node = VP_TO_TMPFS_NODE(vp);
if (uio->uio_offset < 0)
return (EINVAL);
if (vp->v_type != VREG)
return (EINVAL);
while (uio->uio_resid > 0 && uio->uio_offset < node->tn_size) {
/*
* Use buffer cache I/O (via tmpfs_strategy)
*/
offset = (size_t)uio->uio_offset & BMASK;
base_offset = (off_t)uio->uio_offset - offset;
bp = getcacheblk(vp, base_offset, BSIZE, 0);
if (bp == NULL) {
lwkt_gettoken(&vp->v_mount->mnt_token);
error = bread(vp, base_offset, BSIZE, &bp);
if (error) {
brelse(bp);
lwkt_reltoken(&vp->v_mount->mnt_token);
kprintf("tmpfs_read bread error %d\n", error);
break;
}
lwkt_reltoken(&vp->v_mount->mnt_token);
}
/*
* Figure out how many bytes we can actually copy this loop.
*/
len = BSIZE - offset;
if (len > uio->uio_resid)
len = uio->uio_resid;
if (len > node->tn_size - uio->uio_offset)
len = (size_t)(node->tn_size - uio->uio_offset);
error = uiomovebp(bp, (char *)bp->b_data + offset, len, uio);
bqrelse(bp);
if (error) {
kprintf("tmpfs_read uiomove error %d\n", error);
break;
}
}
TMPFS_NODE_LOCK(node);
node->tn_status |= TMPFS_NODE_ACCESSED;
TMPFS_NODE_UNLOCK(node);
return(error);
}
