+/* Extend the file by 'blocks' blocks, return the number of extents added */
+int udf_extend_file(struct inode *inode, struct extent_position *last_pos,
+ kernel_long_ad *last_ext, sector_t blocks)
+{
+ sector_t add;
+ int count = 0, fake = !(last_ext->extLength & UDF_EXTENT_LENGTH_MASK);
+ struct super_block *sb = inode->i_sb;
+ kernel_lb_addr prealloc_loc = {0, 0};
+ int prealloc_len = 0;
+
+ /* The previous extent is fake and we should not extend by anything
+ * - there's nothing to do... */
+ if (!blocks && fake)
+ return 0;
+ /* Round the last extent up to a multiple of block size */
+ if (last_ext->extLength & (sb->s_blocksize - 1)) {
+ last_ext->extLength =
+ (last_ext->extLength & UDF_EXTENT_FLAG_MASK) |
+ (((last_ext->extLength & UDF_EXTENT_LENGTH_MASK) +
+ sb->s_blocksize - 1) & ~(sb->s_blocksize - 1));
+ UDF_I_LENEXTENTS(inode) =
+ (UDF_I_LENEXTENTS(inode) + sb->s_blocksize - 1) &
+ ~(sb->s_blocksize - 1);
+ }
+ /* Last extent are just preallocated blocks? */
+ if ((last_ext->extLength & UDF_EXTENT_FLAG_MASK) == EXT_NOT_RECORDED_ALLOCATED) {
+ /* Save the extent so that we can reattach it to the end */
+ prealloc_loc = last_ext->extLocation;
+ prealloc_len = last_ext->extLength;
+ /* Mark the extent as a hole */
+ last_ext->extLength = EXT_NOT_RECORDED_NOT_ALLOCATED |
+ (last_ext->extLength & UDF_EXTENT_LENGTH_MASK);
+ last_ext->extLocation.logicalBlockNum = 0;
+ last_ext->extLocation.partitionReferenceNum = 0;
+ }
+ /* Can we merge with the previous extent? */
+ if ((last_ext->extLength & UDF_EXTENT_FLAG_MASK) == EXT_NOT_RECORDED_NOT_ALLOCATED) {
+ add = ((1<<30) - sb->s_blocksize - (last_ext->extLength &
+ UDF_EXTENT_LENGTH_MASK)) >> sb->s_blocksize_bits;
+ if (add > blocks)
+ add = blocks;
+ blocks -= add;
+ last_ext->extLength += add << sb->s_blocksize_bits;
+ }
+
+ if (fake) {
+ udf_add_aext(inode, last_pos, last_ext->extLocation,
+ last_ext->extLength, 1);
+ count++;
+ }
+ else
+ udf_write_aext(inode, last_pos, last_ext->extLocation, last_ext->extLength, 1);
+ /* Managed to do everything necessary? */
+ if (!blocks)
+ goto out;
+
+ /* All further extents will be NOT_RECORDED_NOT_ALLOCATED */
+ last_ext->extLocation.logicalBlockNum = 0;
+ last_ext->extLocation.partitionReferenceNum = 0;
+ add = (1 << (30-sb->s_blocksize_bits)) - 1;
+ last_ext->extLength = EXT_NOT_RECORDED_NOT_ALLOCATED | (add << sb->s_blocksize_bits);
+ /* Create enough extents to cover the whole hole */
+ while (blocks > add) {
+ blocks -= add;
+ if (udf_add_aext(inode, last_pos, last_ext->extLocation,
+ last_ext->extLength, 1) == -1)
+ return -1;
+ count++;
+ }
+ if (blocks) {
+ last_ext->extLength = EXT_NOT_RECORDED_NOT_ALLOCATED |
+ (blocks << sb->s_blocksize_bits);
+ if (udf_add_aext(inode, last_pos, last_ext->extLocation,
+ last_ext->extLength, 1) == -1)
+ return -1;
+ count++;
+ }
+out:
+ /* Do we have some preallocated blocks saved? */
+ if (prealloc_len) {
+ if (udf_add_aext(inode, last_pos, prealloc_loc, prealloc_len, 1) == -1)
+ return -1;
+ last_ext->extLocation = prealloc_loc;
+ last_ext->extLength = prealloc_len;
+ count++;
+ }
+ /* last_pos should point to the last written extent... */
+ if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_SHORT)
+ last_pos->offset -= sizeof(short_ad);
+ else if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_LONG)
+ last_pos->offset -= sizeof(long_ad);
+ else
+ return -1;
+ return count;
+}
+
+static struct buffer_head * inode_getblk(struct inode * inode, sector_t block,