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[Linux-cluster] Re: GFS



David Teigland writes:
+static ssize_t walk_vm_hard(struct file *file, char *buf, size_t size,
+                         loff_t *offset, do_rw_t operation)
+{
+     struct gfs2_holder *ghs;
+     unsigned int num_gh = 0;
+     ssize_t count;
+
+     {

Can we please get rid of the extra braces everywhere?


[snip]

David Teigland writes:
+
+             for (vma = find_vma(mm, start); vma; vma = vma->vm_next) {
+                     if (end <= vma->vm_start)
+                             break;
+                     if (vma->vm_file &&
+                         vma->vm_file->f_dentry->d_inode->i_sb == sb) {
+                             num_gh++;
+                     }
+             }
+
+             ghs = kmalloc((num_gh + 1) * sizeof(struct gfs2_holder),
+                           GFP_KERNEL);
+             if (!ghs) {
+                     if (!dumping)
+                             up_read(&mm->mmap_sem);
+                     return -ENOMEM;
+             }
+
+             for (vma = find_vma(mm, start); vma; vma = vma->vm_next) {

Sorry if this is an obvious question but what prevents another thread from doing mmap() before we do the second walk and messing up num_gh?


+                     if (end <= vma->vm_start)
+                             break;
+                     if (vma->vm_file) {
+                             struct inode *inode;
+                             inode = vma->vm_file->f_dentry->d_inode;
+                             if (inode->i_sb == sb)
+                                     gfs2_holder_init(get_v2ip(inode)->i_gl,
+                                                      vma2state(vma),
+                                                      0, &ghs[x++]);
+                     }
+             }

Pekka



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