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    SubjectRe: [PATCH 2/2][RFC][BUG] msync: updating ctime and mtime at syncing
    2008/1/12, Peter Zijlstra <a.p.zijlstra@chello.nl>:
    >
    > On Fri, 2008-01-11 at 03:44 +0300, Anton Salikhmetov wrote:
    >
    > > +/*
    > > + * Update the ctime and mtime stamps after checking if they are to be updated.
    > > + */
    > > +void mapped_file_update_time(struct file *file)
    > > +{
    > > + if (test_and_clear_bit(AS_MCTIME, &file->f_mapping->flags)) {
    > > + get_file(file);
    > > + file_update_time(file);
    > > + fput(file);
    > > + }
    > > +}
    > > +
    >
    > I don't think you need the get/put file stuff here, because
    >
    > > @@ -87,6 +87,8 @@ long do_fsync(struct file *file, int datasync)
    > > goto out;
    > > }
    > >
    > > + mapped_file_update_time(file);
    > > +
    > > ret = filemap_fdatawrite(mapping);
    > >
    > > /*
    >
    > at this call-site we already hold an extra reference on the file, and
    >
    > > @@ -74,14 +79,17 @@ asmlinkage long sys_msync(unsigned long start, size_t len, int flags)
    > > break;
    > > }
    > > file = vma->vm_file;
    > > - if ((flags & MS_SYNC) && file && (vma->vm_flags & VM_SHARED)) {
    > > - get_file(file);
    > > - up_read(&mm->mmap_sem);
    > > - error = do_fsync(file, 0);
    > > - fput(file);
    > > - if (error)
    > > - return error;
    > > - down_read(&mm->mmap_sem);
    > > + if (file && (vma->vm_flags & VM_SHARED)) {
    > > + mapped_file_update_time(file);
    > > + if (flags & MS_SYNC) {
    > > + get_file(file);
    > > + up_read(&mm->mmap_sem);
    > > + error = do_fsync(file, 0);
    > > + fput(file);
    > > + if (error)
    > > + return error;
    > > + down_read(&mm->mmap_sem);
    > > + }
    > > }
    > >
    > > start = vma->vm_end;
    >
    > here we hold the mmap_sem so the vma reference on the file can't go
    > away.

    These get_file() and fput() calls were in the sys_msync() function form before
    all my changes. I did not add them here.

    >
    >


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