+static void __udf_clear_extent_cache(struct inode *inode)
+{
+ struct udf_inode_info *iinfo = UDF_I(inode);
+
+ if (iinfo->cached_extent.lstart != -1) {
+ brelse(iinfo->cached_extent.epos.bh);
+ iinfo->cached_extent.lstart = -1;
+ }
+}
+
+/* Invalidate extent cache */
+static void udf_clear_extent_cache(struct inode *inode)
+{
+ struct udf_inode_info *iinfo = UDF_I(inode);
+
+ spin_lock(&iinfo->i_extent_cache_lock);
+ __udf_clear_extent_cache(inode);
+ spin_unlock(&iinfo->i_extent_cache_lock);
+}
+
+/* Return contents of extent cache */
+static int udf_read_extent_cache(struct inode *inode, loff_t bcount,
+ loff_t *lbcount, struct extent_position *pos)
+{
+ struct udf_inode_info *iinfo = UDF_I(inode);
+ int ret = 0;
+
+ spin_lock(&iinfo->i_extent_cache_lock);
+ if ((iinfo->cached_extent.lstart <= bcount) &&
+ (iinfo->cached_extent.lstart != -1)) {
+ /* Cache hit */
+ *lbcount = iinfo->cached_extent.lstart;
+ memcpy(pos, &iinfo->cached_extent.epos,
+ sizeof(struct extent_position));
+ if (pos->bh)
+ get_bh(pos->bh);
+ ret = 1;
+ }
+ spin_unlock(&iinfo->i_extent_cache_lock);
+ return ret;
+}
+
+/* Add extent to extent cache */
+static void udf_update_extent_cache(struct inode *inode, loff_t estart,
+ struct extent_position *pos, int next_epos)
+{
+ struct udf_inode_info *iinfo = UDF_I(inode);
+
+ spin_lock(&iinfo->i_extent_cache_lock);
+ /* Invalidate previously cached extent */
+ __udf_clear_extent_cache(inode);
+ if (pos->bh)
+ get_bh(pos->bh);
+ memcpy(&iinfo->cached_extent.epos, pos,
+ sizeof(struct extent_position));
+ iinfo->cached_extent.lstart = estart;
+ if (next_epos)
+ switch (iinfo->i_alloc_type) {
+ case ICBTAG_FLAG_AD_SHORT:
+ iinfo->cached_extent.epos.offset -=
+ sizeof(struct short_ad);
+ break;
+ case ICBTAG_FLAG_AD_LONG:
+ iinfo->cached_extent.epos.offset -=
+ sizeof(struct long_ad);
+ }
+ spin_unlock(&iinfo->i_extent_cache_lock);
+}