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| author | Oleg Nesterov <oleg@tv-sign.ru> | 2008-04-28 02:12:10 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-04-28 08:58:18 -0700 |
| commit | 4d3d5b41a72b52555d43efbfc4ccde6ba6e5444f (patch) | |
| tree | 5935f5d9e741f63c190c4edf4d5f6f6005e33d0f /mm/mmap.c | |
| parent | 0dd1334faf7e075bfdb6f5284eed65210b296fc1 (diff) | |
| download | lwn-4d3d5b41a72b52555d43efbfc4ccde6ba6e5444f.tar.gz lwn-4d3d5b41a72b52555d43efbfc4ccde6ba6e5444f.zip | |
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: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/mmap.c')
| -rw-r--r-- | mm/mmap.c | 23 |
1 files changed, 10 insertions, 13 deletions
diff --git a/mm/mmap.c b/mm/mmap.c index a32d28ce31cd..6aaf657adb87 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -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 @@ munmap_back: 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) { |