提交 4d3d5b41 编写于 作者: O Oleg Nesterov 提交者: Linus Torvalds

mmap_region: cleanup the final vma_merge() related code

It is not easy to actually understand the "if (!file || !vma_merge())"
code, turn it into "if (file && vma_merge())".  This makes immediately
obvious that the subsequent "if (file)" is superfluous.

As Hugh Dickins pointed out, we can also factor out the ->i_writecount
corrections, and add a small comment about that.
Signed-off-by: NOleg Nesterov <oleg@tv-sign.ru>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
上级 0dd1334f
......@@ -1068,7 +1068,6 @@ int vma_wants_writenotify(struct vm_area_struct *vma)
mapping_cap_account_dirty(vma->vm_file->f_mapping);
}
unsigned long mmap_region(struct file *file, unsigned long addr,
unsigned long len, unsigned long flags,
unsigned int vm_flags, unsigned long pgoff,
......@@ -1181,22 +1180,20 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
if (vma_wants_writenotify(vma))
vma->vm_page_prot = vm_get_page_prot(vm_flags & ~VM_SHARED);
if (!file || !vma_merge(mm, prev, addr, vma->vm_end,
if (file && vma_merge(mm, prev, addr, vma->vm_end,
vma->vm_flags, NULL, file, pgoff, vma_policy(vma))) {
file = vma->vm_file;
vma_link(mm, vma, prev, rb_link, rb_parent);
if (correct_wcount)
atomic_inc(&inode->i_writecount);
} else {
if (file) {
if (correct_wcount)
atomic_inc(&inode->i_writecount);
fput(file);
}
mpol_free(vma_policy(vma));
kmem_cache_free(vm_area_cachep, vma);
fput(file);
} else {
vma_link(mm, vma, prev, rb_link, rb_parent);
file = vma->vm_file;
}
out:
/* Once vma denies write, undo our temporary denial count */
if (correct_wcount)
atomic_inc(&inode->i_writecount);
out:
mm->total_vm += len >> PAGE_SHIFT;
vm_stat_account(mm, vm_flags, file, len >> PAGE_SHIFT);
if (vm_flags & VM_LOCKED) {
......
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