#include <linux/mempolicy.h>
#include <linux/page-isolation.h>
#include <linux/hugetlb.h>
+#include <linux/falloc.h>
#include <linux/sched.h>
#include <linux/ksm.h>
+#include <linux/fs.h>
+#include <linux/file.h>
/*
* Any behaviour which results in changes to the vma->vm_flags needs to
struct vm_area_struct **prev,
unsigned long start, unsigned long end)
{
- struct address_space *mapping;
- loff_t offset, endoff;
+ loff_t offset;
int error;
+ struct file *f;
*prev = NULL; /* tell sys_madvise we drop mmap_sem */
if (vma->vm_flags & (VM_LOCKED|VM_NONLINEAR|VM_HUGETLB))
return -EINVAL;
- if (!vma->vm_file || !vma->vm_file->f_mapping
- || !vma->vm_file->f_mapping->host) {
+ f = vma->vm_file;
+
+ if (!f || !f->f_mapping || !f->f_mapping->host) {
return -EINVAL;
}
if ((vma->vm_flags & (VM_SHARED|VM_WRITE)) != (VM_SHARED|VM_WRITE))
return -EACCES;
- mapping = vma->vm_file->f_mapping;
-
offset = (loff_t)(start - vma->vm_start)
+ ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
- endoff = (loff_t)(end - vma->vm_start - 1)
- + ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
- /* vmtruncate_range needs to take i_mutex */
+ /*
+ * Filesystem's fallocate may need to take i_mutex. We need to
+ * explicitly grab a reference because the vma (and hence the
+ * vma's reference to the file) can go away as soon as we drop
+ * mmap_sem.
+ */
+ get_file(f);
up_read(¤t->mm->mmap_sem);
- error = vmtruncate_range(mapping->host, offset, endoff);
+ error = do_fallocate(f,
+ FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
+ offset, end - start);
+ fput(f);
down_read(¤t->mm->mmap_sem);
return error;
}