/*
* Routine: macx_swapon
* Function:
* Syscall interface to add a file to backing store
*/
int
macx_swapon(
struct macx_swapon_args *args)
{
int size = args->size;
vnode_t vp = (vnode_t)NULL;
struct nameidata nd, *ndp;
register int error;
kern_return_t kr;
mach_port_t backing_store;
memory_object_default_t default_pager;
int i;
boolean_t funnel_state;
off_t file_size;
vfs_context_t ctx = vfs_context_current();
struct proc *p = current_proc();
int dp_cluster_size;
AUDIT_MACH_SYSCALL_ENTER(AUE_SWAPON);
AUDIT_ARG(value32, args->priority);
funnel_state = thread_funnel_set(kernel_flock, TRUE);
ndp = &nd;
if ((error = suser(kauth_cred_get(), 0)))
goto swapon_bailout;
/*
* Get a vnode for the paging area.
*/
NDINIT(ndp, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNPATH1,
((IS_64BIT_PROCESS(p)) ? UIO_USERSPACE64 : UIO_USERSPACE32),
(user_addr_t) args->filename, ctx);
if ((error = namei(ndp)))
goto swapon_bailout;
nameidone(ndp);
vp = ndp->ni_vp;
if (vp->v_type != VREG) {
error = EINVAL;
goto swapon_bailout;
}
/* get file size */
if ((error = vnode_size(vp, &file_size, ctx)) != 0)
goto swapon_bailout;
#if CONFIG_MACF
vnode_lock(vp);
error = mac_system_check_swapon(vfs_context_ucred(ctx), vp);
vnode_unlock(vp);
if (error)
goto swapon_bailout;
#endif
/* resize to desired size if it's too small */
if ((file_size < (off_t)size) && ((error = vnode_setsize(vp, (off_t)size, 0, ctx)) != 0))
goto swapon_bailout;
if (default_pager_init_flag == 0) {
start_def_pager(NULL);
default_pager_init_flag = 1;
}
/* add new backing store to list */
i = 0;
while(bs_port_table[i].vp != 0) {
if(i == MAX_BACKING_STORE)
break;
i++;
}
if(i == MAX_BACKING_STORE) {
error = ENOMEM;
goto swapon_bailout;
}
/* remember the vnode. This vnode has namei() reference */
bs_port_table[i].vp = vp;
/*
* Look to see if we are already paging to this file.
*/
/* make certain the copy send of kernel call will work */
default_pager = MEMORY_OBJECT_DEFAULT_NULL;
kr = host_default_memory_manager(host_priv_self(), &default_pager, 0);
if(kr != KERN_SUCCESS) {
error = EAGAIN;
bs_port_table[i].vp = 0;
goto swapon_bailout;
}
if (vp->v_mount->mnt_kern_flag & MNTK_SSD) {
/*
* keep the cluster size small since the
* seek cost is effectively 0 which means
* we don't care much about fragmentation
*/
dp_isssd = TRUE;
dp_cluster_size = 2 * PAGE_SIZE;
} else {
/*
* use the default cluster size
*/
dp_isssd = FALSE;
dp_cluster_size = 0;
}
kr = default_pager_backing_store_create(default_pager,
-1, /* default priority */
dp_cluster_size,
&backing_store);
memory_object_default_deallocate(default_pager);
if(kr != KERN_SUCCESS) {
error = ENOMEM;
bs_port_table[i].vp = 0;
goto swapon_bailout;
}
/* Mark this vnode as being used for swapfile */
vnode_lock_spin(vp);
SET(vp->v_flag, VSWAP);
vnode_unlock(vp);
/*
* NOTE: we are able to supply PAGE_SIZE here instead of
* an actual record size or block number because:
* a: we do not support offsets from the beginning of the
* file (allowing for non page size/record modulo offsets.
* b: because allow paging will be done modulo page size
*/
kr = default_pager_add_file(backing_store, (vnode_ptr_t) vp,
PAGE_SIZE, (int)(file_size/PAGE_SIZE));
if(kr != KERN_SUCCESS) {
bs_port_table[i].vp = 0;
if(kr == KERN_INVALID_ARGUMENT)
error = EINVAL;
else
error = ENOMEM;
/* This vnode is not to be used for swapfile */
vnode_lock_spin(vp);
CLR(vp->v_flag, VSWAP);
vnode_unlock(vp);
goto swapon_bailout;
}
bs_port_table[i].bs = (void *)backing_store;
error = 0;
ubc_setthreadcred(vp, p, current_thread());
/*
* take a long term reference on the vnode to keep
* vnreclaim() away from this vnode.
*/
vnode_ref(vp);
swapon_bailout:
if (vp) {
vnode_put(vp);
}
(void) thread_funnel_set(kernel_flock, FALSE);
AUDIT_MACH_SYSCALL_EXIT(error);
return(error);
}
/*
* Routine: macx_swapon
* Function:
* Syscall interface to add a file to backing store
*/
int
macx_swapon(
char *filename,
int flags,
long size,
long priority)
{
struct vnode *vp = 0;
struct nameidata nd, *ndp;
struct proc *p = current_proc();
pager_file_t pf;
register int error;
kern_return_t kr;
mach_port_t backing_store;
memory_object_default_t default_pager;
int i;
boolean_t funnel_state;
struct vattr vattr;
AUDIT_MACH_SYSCALL_ENTER(AUE_SWAPON);
AUDIT_ARG(value, priority);
funnel_state = thread_funnel_set(kernel_flock, TRUE);
ndp = &nd;
if ((error = suser(p->p_ucred, &p->p_acflag)))
goto swapon_bailout;
if(default_pager_init_flag == 0) {
start_def_pager(NULL);
default_pager_init_flag = 1;
}
/*
* Get a vnode for the paging area.
*/
NDINIT(ndp, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNPATH1, UIO_USERSPACE,
filename, p);
if ((error = namei(ndp)))
goto swapon_bailout;
vp = ndp->ni_vp;
if (vp->v_type != VREG) {
error = EINVAL;
VOP_UNLOCK(vp, 0, p);
goto swapon_bailout;
}
UBCINFOCHECK("macx_swapon", vp);
if (error = VOP_GETATTR(vp, &vattr, p->p_ucred, p)) {
VOP_UNLOCK(vp, 0, p);
goto swapon_bailout;
}
if (vattr.va_size < (u_quad_t)size) {
vattr_null(&vattr);
vattr.va_size = (u_quad_t)size;
error = VOP_SETATTR(vp, &vattr, p->p_ucred, p);
if (error) {
VOP_UNLOCK(vp, 0, p);
goto swapon_bailout;
}
}
/* add new backing store to list */
i = 0;
while(bs_port_table[i].vp != 0) {
if(i == MAX_BACKING_STORE)
break;
i++;
}
if(i == MAX_BACKING_STORE) {
error = ENOMEM;
VOP_UNLOCK(vp, 0, p);
goto swapon_bailout;
}
/* remember the vnode. This vnode has namei() reference */
bs_port_table[i].vp = vp;
/*
* Look to see if we are already paging to this file.
*/
/* make certain the copy send of kernel call will work */
default_pager = MEMORY_OBJECT_DEFAULT_NULL;
kr = host_default_memory_manager(host_priv_self(), &default_pager, 0);
if(kr != KERN_SUCCESS) {
error = EAGAIN;
VOP_UNLOCK(vp, 0, p);
bs_port_table[i].vp = 0;
goto swapon_bailout;
}
kr = default_pager_backing_store_create(default_pager,
-1, /* default priority */
0, /* default cluster size */
&backing_store);
memory_object_default_deallocate(default_pager);
if(kr != KERN_SUCCESS) {
error = ENOMEM;
VOP_UNLOCK(vp, 0, p);
bs_port_table[i].vp = 0;
goto swapon_bailout;
}
/*
* NOTE: we are able to supply PAGE_SIZE here instead of
* an actual record size or block number because:
* a: we do not support offsets from the beginning of the
* file (allowing for non page size/record modulo offsets.
* b: because allow paging will be done modulo page size
*/
VOP_UNLOCK(vp, 0, p);
kr = default_pager_add_file(backing_store, vp, PAGE_SIZE,
((int)vattr.va_size)/PAGE_SIZE);
if(kr != KERN_SUCCESS) {
bs_port_table[i].vp = 0;
if(kr == KERN_INVALID_ARGUMENT)
error = EINVAL;
else
error = ENOMEM;
goto swapon_bailout;
}
bs_port_table[i].bs = (void *)backing_store;
error = 0;
if (!ubc_hold(vp))
panic("macx_swapon: hold");
/* Mark this vnode as being used for swapfile */
SET(vp->v_flag, VSWAP);
ubc_setcred(vp, p);
/*
* take an extra reference on the vnode to keep
* vnreclaim() away from this vnode.
*/
VREF(vp);
/* Hold on to the namei reference to the paging file vnode */
vp = 0;
swapon_bailout:
if (vp) {
vrele(vp);
}
(void) thread_funnel_set(kernel_flock, FALSE);
AUDIT_MACH_SYSCALL_EXIT(error);
return(error);
}
