static int ll_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
int count = 0;
bool printed = false;
int result;
sigset_t set;
/* Only SIGKILL and SIGTERM is allowed for fault/nopage/mkwrite
* so that it can be killed by admin but not cause segfault by
* other signals. */
set = cfs_block_sigsinv(sigmask(SIGKILL) | sigmask(SIGTERM));
ll_stats_ops_tally(ll_i2sbi(file_inode(vma->vm_file)),
LPROC_LL_FAULT, 1);
restart:
result = ll_fault0(vma, vmf);
if (!(result & (VM_FAULT_RETRY | VM_FAULT_ERROR | VM_FAULT_LOCKED))) {
struct page *vmpage = vmf->page;
/* check if this page has been truncated */
lock_page(vmpage);
if (unlikely(vmpage->mapping == NULL)) { /* unlucky */
unlock_page(vmpage);
put_page(vmpage);
vmf->page = NULL;
if (!printed && ++count > 16) {
CWARN("the page is under heavy contention,"
"maybe your app(%s) needs revising :-)\n",
current->comm);
printed = true;
}
goto restart;
}
result |= VM_FAULT_LOCKED;
}
cfs_restore_sigs(set);
return result;
}
static int ll_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
int count = 0;
bool printed = false;
int result;
sigset_t set;
/* Only SIGKILL and SIGTERM are allowed for fault/nopage/mkwrite
* so that it can be killed by admin but not cause segfault by
* other signals.
*/
set = cfs_block_sigsinv(sigmask(SIGKILL) | sigmask(SIGTERM));
restart:
result = ll_fault0(vma, vmf);
LASSERT(!(result & VM_FAULT_LOCKED));
if (result == 0) {
struct page *vmpage = vmf->page;
/* check if this page has been truncated */
lock_page(vmpage);
if (unlikely(!vmpage->mapping)) { /* unlucky */
unlock_page(vmpage);
page_cache_release(vmpage);
vmf->page = NULL;
if (!printed && ++count > 16) {
CWARN("the page is under heavy contention, maybe your app(%s) needs revising :-)\n",
current->comm);
printed = true;
}
goto restart;
}
result = VM_FAULT_LOCKED;
}
cfs_restore_sigs(set);
return result;
}
