static struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid,
u64 root_objectid, u32 generation,
int check_generation)
{
struct btrfs_fs_info *fs_info = btrfs_sb(sb);
struct btrfs_root *root;
struct inode *inode;
struct btrfs_key key;
int index;
int err = 0;
if (objectid < BTRFS_FIRST_FREE_OBJECTID)
return ERR_PTR(-ESTALE);
key.objectid = root_objectid;
btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
key.offset = (u64)-1;
index = srcu_read_lock(&fs_info->subvol_srcu);
root = btrfs_read_fs_root_no_name(fs_info, &key);
if (IS_ERR(root)) {
err = PTR_ERR(root);
goto fail;
}
if (btrfs_root_refs(&root->root_item) == 0) {
err = -ENOENT;
goto fail;
}
key.objectid = objectid;
btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
key.offset = 0;
inode = btrfs_iget(sb, &key, root, NULL);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto fail;
}
srcu_read_unlock(&fs_info->subvol_srcu, index);
if (check_generation && generation != inode->i_generation) {
iput(inode);
return ERR_PTR(-ESTALE);
}
return d_obtain_alias(inode);
fail:
srcu_read_unlock(&fs_info->subvol_srcu, index);
return ERR_PTR(err);
}
/*
* Deliver an IRQ in an atomic context if we can, or return a failure,
* user can retry in a process context.
* Return value:
* -EWOULDBLOCK - Can't deliver in atomic context: retry in a process context.
* Other values - No need to retry.
*/
int kvm_set_irq_inatomic(struct kvm *kvm, int irq_source_id, u32 irq, int level)
{
struct kvm_kernel_irq_routing_entry entries[KVM_NR_IRQCHIPS];
struct kvm_kernel_irq_routing_entry *e;
int ret = -EINVAL;
int idx;
trace_kvm_set_irq(irq, level, irq_source_id);
/*
* Injection into either PIC or IOAPIC might need to scan all CPUs,
* which would need to be retried from thread context; when same GSI
* is connected to both PIC and IOAPIC, we'd have to report a
* partial failure here.
* Since there's no easy way to do this, we only support injecting MSI
* which is limited to 1:1 GSI mapping.
*/
idx = srcu_read_lock(&kvm->irq_srcu);
if (kvm_irq_map_gsi(kvm, entries, irq) > 0) {
e = &entries[0];
if (likely(e->type == KVM_IRQ_ROUTING_MSI))
ret = kvm_set_msi_inatomic(e, kvm);
else
ret = -EWOULDBLOCK;
}
srcu_read_unlock(&kvm->irq_srcu, idx);
return ret;
}
int kvmppc_handle_load(struct kvm_run *run, struct kvm_vcpu *vcpu,
unsigned int rt, unsigned int bytes, int is_bigendian)
{
int idx, ret;
if (bytes > sizeof(run->mmio.data)) {
printk(KERN_ERR "%s: bad MMIO length: %d\n", __func__,
run->mmio.len);
}
run->mmio.phys_addr = vcpu->arch.paddr_accessed;
run->mmio.len = bytes;
run->mmio.is_write = 0;
vcpu->arch.io_gpr = rt;
vcpu->arch.mmio_is_bigendian = is_bigendian;
vcpu->mmio_needed = 1;
vcpu->mmio_is_write = 0;
vcpu->arch.mmio_sign_extend = 0;
idx = srcu_read_lock(&vcpu->kvm->srcu);
ret = kvm_io_bus_read(vcpu->kvm, KVM_MMIO_BUS, run->mmio.phys_addr,
bytes, &run->mmio.data);
srcu_read_unlock(&vcpu->kvm->srcu, idx);
if (!ret) {
kvmppc_complete_mmio_load(vcpu, run);
vcpu->mmio_needed = 0;
return EMULATE_DONE;
}
return EMULATE_DO_MMIO;
}
int kvmppc_handle_store(struct kvm_run *run, struct kvm_vcpu *vcpu,
u64 val, unsigned int bytes, int is_default_endian)
{
void *data = run->mmio.data;
int idx, ret;
int is_bigendian;
if (kvmppc_need_byteswap(vcpu)) {
/* Default endianness is "little endian". */
is_bigendian = !is_default_endian;
} else {
/* Default endianness is "big endian". */
is_bigendian = is_default_endian;
}
if (bytes > sizeof(run->mmio.data)) {
printk(KERN_ERR "%s: bad MMIO length: %d\n", __func__,
run->mmio.len);
}
run->mmio.phys_addr = vcpu->arch.paddr_accessed;
run->mmio.len = bytes;
run->mmio.is_write = 1;
vcpu->mmio_needed = 1;
vcpu->mmio_is_write = 1;
/* Store the value at the lowest bytes in 'data'. */
if (is_bigendian) {
switch (bytes) {
case 8: *(u64 *)data = val; break;
case 4: *(u32 *)data = val; break;
case 2: *(u16 *)data = val; break;
case 1: *(u8 *)data = val; break;
}
} else {
/* Store LE value into 'data'. */
switch (bytes) {
case 4: st_le32(data, val); break;
case 2: st_le16(data, val); break;
case 1: *(u8 *)data = val; break;
}
}
idx = srcu_read_lock(&vcpu->kvm->srcu);
ret = kvm_io_bus_write(vcpu->kvm, KVM_MMIO_BUS, run->mmio.phys_addr,
bytes, &run->mmio.data);
srcu_read_unlock(&vcpu->kvm->srcu, idx);
if (!ret) {
vcpu->mmio_needed = 0;
return EMULATE_DONE;
}
return EMULATE_DO_MMIO;
}
int kvmppc_handle_store(struct kvm_run *run, struct kvm_vcpu *vcpu,
u64 val, unsigned int bytes, int is_default_endian)
{
void *data = run->mmio.data;
int idx, ret;
bool host_swabbed;
/* Pity C doesn't have a logical XOR operator */
if (kvmppc_need_byteswap(vcpu)) {
host_swabbed = is_default_endian;
} else {
host_swabbed = !is_default_endian;
}
if (bytes > sizeof(run->mmio.data)) {
printk(KERN_ERR "%s: bad MMIO length: %d\n", __func__,
run->mmio.len);
}
run->mmio.phys_addr = vcpu->arch.paddr_accessed;
run->mmio.len = bytes;
run->mmio.is_write = 1;
vcpu->mmio_needed = 1;
vcpu->mmio_is_write = 1;
/* Store the value at the lowest bytes in 'data'. */
if (!host_swabbed) {
switch (bytes) {
case 8: *(u64 *)data = val; break;
case 4: *(u32 *)data = val; break;
case 2: *(u16 *)data = val; break;
case 1: *(u8 *)data = val; break;
}
} else {
switch (bytes) {
case 8: *(u64 *)data = swab64(val); break;
case 4: *(u32 *)data = swab32(val); break;
case 2: *(u16 *)data = swab16(val); break;
case 1: *(u8 *)data = val; break;
}
}
idx = srcu_read_lock(&vcpu->kvm->srcu);
ret = kvm_io_bus_write(vcpu, KVM_MMIO_BUS, run->mmio.phys_addr,
bytes, &run->mmio.data);
srcu_read_unlock(&vcpu->kvm->srcu, idx);
if (!ret) {
vcpu->mmio_needed = 0;
return EMULATE_DONE;
}
return EMULATE_DO_MMIO;
}
/*! 2016.11.19 study -ing */
int __srcu_notifier_call_chain(struct srcu_notifier_head *nh,
unsigned long val, void *v,
int nr_to_call, int *nr_calls)
{
int ret;
int idx;
idx = srcu_read_lock(&nh->srcu);
ret = notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls);
srcu_read_unlock(&nh->srcu, idx);
return ret;
}
void rcu_reader(void)
{
int idx;
#ifndef FORCE_FAILURE_3
idx = srcu_read_lock(&ss);
#endif
might_sleep();
__unbuffered_tpr_x = x;
#ifdef FORCE_FAILURE
srcu_read_unlock(&ss, idx);
idx = srcu_read_lock(&ss);
#endif
__unbuffered_tpr_y = y;
#ifndef FORCE_FAILURE_3
srcu_read_unlock(&ss, idx);
#endif
might_sleep();
}
void rcu_reader(void)
{
int idx;
#ifndef FORCE_FAILURE_3
idx = srcu_read_lock(&ss);
#endif
might_sleep();
__unbuffered_tpr_y = READ_ONCE(y);
#ifdef FORCE_FAILURE
srcu_read_unlock(&ss, idx);
idx = srcu_read_lock(&ss);
#endif
WRITE_ONCE(x, 1);
#ifndef FORCE_FAILURE_3
srcu_read_unlock(&ss, idx);
#endif
might_sleep();
}
void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
bool mask)
{
struct kvm_irq_mask_notifier *kimn;
int idx, gsi;
idx = srcu_read_lock(&kvm->irq_srcu);
gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);
if (gsi != -1)
hlist_for_each_entry_rcu(kimn, &kvm->mask_notifier_list, link)
if (kimn->irq == gsi)
kimn->func(kimn, mask);
srcu_read_unlock(&kvm->irq_srcu, idx);
}
/**
* stage2_unmap_vm - Unmap Stage-2 RAM mappings
* @kvm: The struct kvm pointer
*
* Go through the memregions and unmap any reguler RAM
* backing memory already mapped to the VM.
*/
void stage2_unmap_vm(struct kvm *kvm)
{
struct kvm_memslots *slots;
struct kvm_memory_slot *memslot;
int idx;
idx = srcu_read_lock(&kvm->srcu);
spin_lock(&kvm->mmu_lock);
slots = kvm_memslots(kvm);
kvm_for_each_memslot(memslot, slots)
stage2_unmap_memslot(kvm, memslot);
spin_unlock(&kvm->mmu_lock);
srcu_read_unlock(&kvm->srcu, idx);
}
int kvmppc_h_pr(struct kvm_vcpu *vcpu, unsigned long cmd)
{
int rc, idx;
switch (cmd) {
case H_ENTER:
return kvmppc_h_pr_enter(vcpu);
case H_REMOVE:
return kvmppc_h_pr_remove(vcpu);
case H_PROTECT:
return kvmppc_h_pr_protect(vcpu);
case H_BULK_REMOVE:
return kvmppc_h_pr_bulk_remove(vcpu);
case H_PUT_TCE:
return kvmppc_h_pr_put_tce(vcpu);
case H_CEDE:
vcpu->arch.shared->msr |= MSR_EE;
kvm_vcpu_block(vcpu);
clear_bit(KVM_REQ_UNHALT, &vcpu->requests);
vcpu->stat.halt_wakeup++;
return EMULATE_DONE;
case H_XIRR:
case H_CPPR:
case H_EOI:
case H_IPI:
case H_IPOLL:
case H_XIRR_X:
if (kvmppc_xics_enabled(vcpu))
return kvmppc_h_pr_xics_hcall(vcpu, cmd);
break;
case H_RTAS:
if (list_empty(&vcpu->kvm->arch.rtas_tokens))
break;
idx = srcu_read_lock(&vcpu->kvm->srcu);
rc = kvmppc_rtas_hcall(vcpu);
srcu_read_unlock(&vcpu->kvm->srcu, idx);
if (rc)
break;
kvmppc_set_gpr(vcpu, 3, 0);
return EMULATE_DONE;
}
return EMULATE_FAIL;
}
int kvmppc_handle_load(struct kvm_run *run, struct kvm_vcpu *vcpu,
unsigned int rt, unsigned int bytes,
int is_default_endian)
{
int idx, ret;
bool host_swabbed;
/* Pity C doesn't have a logical XOR operator */
if (kvmppc_need_byteswap(vcpu)) {
host_swabbed = is_default_endian;
} else {
host_swabbed = !is_default_endian;
}
if (bytes > sizeof(run->mmio.data)) {
printk(KERN_ERR "%s: bad MMIO length: %d\n", __func__,
run->mmio.len);
}
run->mmio.phys_addr = vcpu->arch.paddr_accessed;
run->mmio.len = bytes;
run->mmio.is_write = 0;
vcpu->arch.io_gpr = rt;
vcpu->arch.mmio_host_swabbed = host_swabbed;
vcpu->mmio_needed = 1;
vcpu->mmio_is_write = 0;
vcpu->arch.mmio_sign_extend = 0;
idx = srcu_read_lock(&vcpu->kvm->srcu);
ret = kvm_io_bus_read(vcpu, KVM_MMIO_BUS, run->mmio.phys_addr,
bytes, &run->mmio.data);
srcu_read_unlock(&vcpu->kvm->srcu, idx);
if (!ret) {
kvmppc_complete_mmio_load(vcpu, run);
vcpu->mmio_needed = 0;
return EMULATE_DONE;
}
return EMULATE_DO_MMIO;
}
/**
* kvm_handle_guest_abort - handles all 2nd stage aborts
* @vcpu: the VCPU pointer
* @run: the kvm_run structure
*
* Any abort that gets to the host is almost guaranteed to be caused by a
* missing second stage translation table entry, which can mean that either the
* guest simply needs more memory and we must allocate an appropriate page or it
* can mean that the guest tried to access I/O memory, which is emulated by user
* space. The distinction is based on the IPA causing the fault and whether this
* memory region has been registered as standard RAM by user space.
*/
int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
unsigned long fault_status;
phys_addr_t fault_ipa;
struct kvm_memory_slot *memslot;
bool is_iabt;
gfn_t gfn;
int ret, idx;
is_iabt = kvm_vcpu_trap_is_iabt(vcpu);
fault_ipa = kvm_vcpu_get_fault_ipa(vcpu);
trace_kvm_guest_fault(*vcpu_pc(vcpu), kvm_vcpu_get_hsr(vcpu),
kvm_vcpu_get_hfar(vcpu), fault_ipa);
/* Check the stage-2 fault is trans. fault or write fault */
fault_status = kvm_vcpu_trap_get_fault(vcpu);
if (fault_status != FSC_FAULT && fault_status != FSC_PERM) {
kvm_err("Unsupported fault status: EC=%#x DFCS=%#lx\n",
kvm_vcpu_trap_get_class(vcpu), fault_status);
return -EFAULT;
}
idx = srcu_read_lock(&vcpu->kvm->srcu);
gfn = fault_ipa >> PAGE_SHIFT;
if (!kvm_is_visible_gfn(vcpu->kvm, gfn)) {
if (is_iabt) {
/* Prefetch Abort on I/O address */
kvm_inject_pabt(vcpu, kvm_vcpu_get_hfar(vcpu));
ret = 1;
goto out_unlock;
}
if (fault_status != FSC_FAULT) {
kvm_err("Unsupported fault status on io memory: %#lx\n",
fault_status);
ret = -EFAULT;
goto out_unlock;
}
/*
* The IPA is reported as [MAX:12], so we need to
* complement it with the bottom 12 bits from the
* faulting VA. This is always 12 bits, irrespective
* of the page size.
*/
fault_ipa |= kvm_vcpu_get_hfar(vcpu) & ((1 << 12) - 1);
ret = io_mem_abort(vcpu, run, fault_ipa);
goto out_unlock;
}
memslot = gfn_to_memslot(vcpu->kvm, gfn);
ret = user_mem_abort(vcpu, fault_ipa, gfn, memslot, fault_status);
if (ret == 0)
ret = 1;
out_unlock:
srcu_read_unlock(&vcpu->kvm->srcu, idx);
return ret;
}
/*
* resolve an indirect backref in the form (root_id, key, level)
* to a logical address
*/
static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info,
struct btrfs_path *path, u64 time_seq,
struct __prelim_ref *ref,
struct ulist *parents,
const u64 *extent_item_pos, u64 total_refs)
{
struct btrfs_root *root;
struct btrfs_key root_key;
struct extent_buffer *eb;
int ret = 0;
int root_level;
int level = ref->level;
int index;
root_key.objectid = ref->root_id;
root_key.type = BTRFS_ROOT_ITEM_KEY;
root_key.offset = (u64)-1;
index = srcu_read_lock(&fs_info->subvol_srcu);
root = btrfs_read_fs_root_no_name(fs_info, &root_key);
if (IS_ERR(root)) {
srcu_read_unlock(&fs_info->subvol_srcu, index);
ret = PTR_ERR(root);
goto out;
}
root_level = btrfs_old_root_level(root, time_seq);
if (root_level + 1 == level) {
srcu_read_unlock(&fs_info->subvol_srcu, index);
goto out;
}
path->lowest_level = level;
ret = btrfs_search_old_slot(root, &ref->key_for_search, path, time_seq);
/* root node has been locked, we can release @subvol_srcu safely here */
srcu_read_unlock(&fs_info->subvol_srcu, index);
pr_debug("search slot in root %llu (level %d, ref count %d) returned "
"%d for key (%llu %u %llu)\n",
ref->root_id, level, ref->count, ret,
ref->key_for_search.objectid, ref->key_for_search.type,
ref->key_for_search.offset);
if (ret < 0)
goto out;
eb = path->nodes[level];
while (!eb) {
if (WARN_ON(!level)) {
ret = 1;
goto out;
}
level--;
eb = path->nodes[level];
}
ret = add_all_parents(root, path, parents, ref, level, time_seq,
extent_item_pos, total_refs);
out:
path->lowest_level = 0;
btrfs_release_path(path);
return ret;
}