diff options
Diffstat (limited to '')
| -rw-r--r-- | mm/msync.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/mm/msync.c b/mm/msync.c index c3bd3e75f687..ac4c9bfea2e7 100644 --- a/mm/msync.c +++ b/mm/msync.c @@ -55,9 +55,11 @@ SYSCALL_DEFINE3(msync, unsigned long, start, size_t, len, int, flags) goto out; /* * If the interval [start,end) covers some unmapped address ranges, - * just ignore them, but return -ENOMEM at the end. + * just ignore them, but return -ENOMEM at the end. Besides, if the + * flag is MS_ASYNC (w/o MS_INVALIDATE) the result would be -ENOMEM + * anyway and there is nothing left to do, so return immediately. */ - down_read(&mm->mmap_sem); + mmap_read_lock(mm); vma = find_vma(mm, start); for (;;) { struct file *file; @@ -69,6 +71,8 @@ SYSCALL_DEFINE3(msync, unsigned long, start, size_t, len, int, flags) goto out_unlock; /* Here start < vma->vm_end. */ if (start < vma->vm_start) { + if (flags == MS_ASYNC) + goto out_unlock; start = vma->vm_start; if (start >= end) goto out_unlock; @@ -88,23 +92,23 @@ SYSCALL_DEFINE3(msync, unsigned long, start, size_t, len, int, flags) if ((flags & MS_SYNC) && file && (vma->vm_flags & VM_SHARED)) { get_file(file); - up_read(&mm->mmap_sem); + mmap_read_unlock(mm); error = vfs_fsync_range(file, fstart, fend, 1); fput(file); if (error || start >= end) goto out; - down_read(&mm->mmap_sem); + mmap_read_lock(mm); vma = find_vma(mm, start); } else { if (start >= end) { error = 0; goto out_unlock; } - vma = vma->vm_next; + vma = find_vma(mm, vma->vm_end); } } out_unlock: - up_read(&mm->mmap_sem); + mmap_read_unlock(mm); out: return error ? : unmapped_error; } |