pnfsblock: note written INVAL areas for layoutcommit
[linux-2.6.git] / fs / nfs / blocklayout / extents.c
index 7521940..19fa7b0 100644 (file)
@@ -217,6 +217,48 @@ int bl_is_sector_init(struct pnfs_inval_markings *marks, sector_t isect)
        return rv;
 }
 
+/* Assume start, end already sector aligned */
+static int
+_range_has_tag(struct my_tree *tree, u64 start, u64 end, int32_t tag)
+{
+       struct pnfs_inval_tracking *pos;
+       u64 expect = 0;
+
+       dprintk("%s(%llu, %llu, %i) enter\n", __func__, start, end, tag);
+       list_for_each_entry_reverse(pos, &tree->mtt_stub, it_link) {
+               if (pos->it_sector >= end)
+                       continue;
+               if (!expect) {
+                       if ((pos->it_sector == end - tree->mtt_step_size) &&
+                           (pos->it_tags & (1 << tag))) {
+                               expect = pos->it_sector - tree->mtt_step_size;
+                               if (pos->it_sector < tree->mtt_step_size || expect < start)
+                                       return 1;
+                               continue;
+                       } else {
+                               return 0;
+                       }
+               }
+               if (pos->it_sector != expect || !(pos->it_tags & (1 << tag)))
+                       return 0;
+               expect -= tree->mtt_step_size;
+               if (expect < start)
+                       return 1;
+       }
+       return 0;
+}
+
+static int is_range_written(struct pnfs_inval_markings *marks,
+                           sector_t start, sector_t end)
+{
+       int rv;
+
+       spin_lock(&marks->im_lock);
+       rv = _range_has_tag(&marks->im_tree, start, end, EXTENT_WRITTEN);
+       spin_unlock(&marks->im_lock);
+       return rv;
+}
+
 /* Marks sectors in [offest, offset_length) as having been initialized.
  * All lengths are step-aligned, where step is min(pagesize, blocksize).
  * Notes where partial block is initialized, and helps prepare it for
@@ -396,6 +438,59 @@ static void add_to_commitlist(struct pnfs_block_layout *bl,
        print_clist(clist, bl->bl_count);
 }
 
+/* Note the range described by offset, length is guaranteed to be contained
+ * within be.
+ */
+int bl_mark_for_commit(struct pnfs_block_extent *be,
+                   sector_t offset, sector_t length)
+{
+       sector_t new_end, end = offset + length;
+       struct pnfs_block_short_extent *new;
+       struct pnfs_block_layout *bl = container_of(be->be_inval,
+                                                   struct pnfs_block_layout,
+                                                   bl_inval);
+
+       new = kmalloc(sizeof(*new), GFP_NOFS);
+       if (!new)
+               return -ENOMEM;
+
+       mark_written_sectors(be->be_inval, offset, length);
+       /* We want to add the range to commit list, but it must be
+        * block-normalized, and verified that the normalized range has
+        * been entirely written to disk.
+        */
+       new->bse_f_offset = offset;
+       offset = normalize(offset, bl->bl_blocksize);
+       if (offset < new->bse_f_offset) {
+               if (is_range_written(be->be_inval, offset, new->bse_f_offset))
+                       new->bse_f_offset = offset;
+               else
+                       new->bse_f_offset = offset + bl->bl_blocksize;
+       }
+       new_end = normalize_up(end, bl->bl_blocksize);
+       if (end < new_end) {
+               if (is_range_written(be->be_inval, end, new_end))
+                       end = new_end;
+               else
+                       end = new_end - bl->bl_blocksize;
+       }
+       if (end <= new->bse_f_offset) {
+               kfree(new);
+               return 0;
+       }
+       new->bse_length = end - new->bse_f_offset;
+       new->bse_devid = be->be_devid;
+       new->bse_mdev = be->be_mdev;
+
+       spin_lock(&bl->bl_ext_lock);
+       /* new will be freed, either by add_to_commitlist if it decides not
+        * to use it, or after LAYOUTCOMMIT uses it in the commitlist.
+        */
+       add_to_commitlist(bl, new);
+       spin_unlock(&bl->bl_ext_lock);
+       return 0;
+}
+
 static void print_bl_extent(struct pnfs_block_extent *be)
 {
        dprintk("PRINT EXTENT extent %p\n", be);