+ /*
+ * If the uninitialized extent begins at the same logical
+ * block where the write begins, and the write completely
+ * covers the extent, then we don't need to split it.
+ */
+ if ((iblock == ee_block) && (allocated <= max_blocks))
+ return allocated;
+
+ err = ext4_ext_get_access(handle, inode, path + depth);
+ if (err)
+ goto out;
+ /* ex1: ee_block to iblock - 1 : uninitialized */
+ if (iblock > ee_block) {
+ ex1 = ex;
+ ex1->ee_len = cpu_to_le16(iblock - ee_block);
+ ext4_ext_mark_uninitialized(ex1);
+ ex2 = &newex;
+ }
+ /*
+ * for sanity, update the length of the ex2 extent before
+ * we insert ex3, if ex1 is NULL. This is to avoid temporary
+ * overlap of blocks.
+ */
+ if (!ex1 && allocated > max_blocks)
+ ex2->ee_len = cpu_to_le16(max_blocks);
+ /* ex3: to ee_block + ee_len : uninitialised */
+ if (allocated > max_blocks) {
+ unsigned int newdepth;
+ ex3 = &newex;
+ ex3->ee_block = cpu_to_le32(iblock + max_blocks);
+ ext4_ext_store_pblock(ex3, newblock + max_blocks);
+ ex3->ee_len = cpu_to_le16(allocated - max_blocks);
+ ext4_ext_mark_uninitialized(ex3);
+ err = ext4_ext_insert_extent(handle, inode, path, ex3, flags);
+ if (err == -ENOSPC) {
+ err = ext4_ext_zeroout(inode, &orig_ex);
+ if (err)
+ goto fix_extent_len;
+ /* update the extent length and mark as initialized */
+ ex->ee_block = orig_ex.ee_block;
+ ex->ee_len = orig_ex.ee_len;
+ ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
+ ext4_ext_dirty(handle, inode, path + depth);
+ /* zeroed the full extent */
+ /* blocks available from iblock */
+ return allocated;
+
+ } else if (err)
+ goto fix_extent_len;
+ /*
+ * The depth, and hence eh & ex might change
+ * as part of the insert above.
+ */
+ newdepth = ext_depth(inode);
+ /*
+ * update the extent length after successful insert of the
+ * split extent
+ */
+ orig_ex.ee_len = cpu_to_le16(ee_len -
+ ext4_ext_get_actual_len(ex3));
+ depth = newdepth;
+ ext4_ext_drop_refs(path);
+ path = ext4_ext_find_extent(inode, iblock, path);
+ if (IS_ERR(path)) {
+ err = PTR_ERR(path);
+ goto out;
+ }
+ eh = path[depth].p_hdr;
+ ex = path[depth].p_ext;
+ if (ex2 != &newex)
+ ex2 = ex;
+
+ err = ext4_ext_get_access(handle, inode, path + depth);
+ if (err)
+ goto out;
+
+ allocated = max_blocks;
+ }
+ /*
+ * If there was a change of depth as part of the
+ * insertion of ex3 above, we need to update the length
+ * of the ex1 extent again here
+ */
+ if (ex1 && ex1 != ex) {
+ ex1 = ex;
+ ex1->ee_len = cpu_to_le16(iblock - ee_block);
+ ext4_ext_mark_uninitialized(ex1);
+ ex2 = &newex;
+ }
+ /*
+ * ex2: iblock to iblock + maxblocks-1 : to be direct IO written,
+ * uninitialised still.
+ */
+ ex2->ee_block = cpu_to_le32(iblock);
+ ext4_ext_store_pblock(ex2, newblock);
+ ex2->ee_len = cpu_to_le16(allocated);
+ ext4_ext_mark_uninitialized(ex2);
+ if (ex2 != ex)
+ goto insert;
+ /* Mark modified extent as dirty */
+ err = ext4_ext_dirty(handle, inode, path + depth);
+ ext_debug("out here\n");
+ goto out;
+insert:
+ err = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
+ if (err == -ENOSPC) {
+ err = ext4_ext_zeroout(inode, &orig_ex);
+ if (err)
+ goto fix_extent_len;
+ /* update the extent length and mark as initialized */
+ ex->ee_block = orig_ex.ee_block;
+ ex->ee_len = orig_ex.ee_len;
+ ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
+ ext4_ext_dirty(handle, inode, path + depth);
+ /* zero out the first half */
+ return allocated;
+ } else if (err)
+ goto fix_extent_len;
+out:
+ ext4_ext_show_leaf(inode, path);
+ return err ? err : allocated;
+
+fix_extent_len:
+ ex->ee_block = orig_ex.ee_block;
+ ex->ee_len = orig_ex.ee_len;
+ ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
+ ext4_ext_mark_uninitialized(ex);
+ ext4_ext_dirty(handle, inode, path + depth);
+ return err;
+}
+static int ext4_convert_unwritten_extents_dio(handle_t *handle,
+ struct inode *inode,
+ struct ext4_ext_path *path)
+{
+ struct ext4_extent *ex;
+ struct ext4_extent_header *eh;
+ int depth;
+ int err = 0;
+ int ret = 0;
+
+ depth = ext_depth(inode);
+ eh = path[depth].p_hdr;
+ ex = path[depth].p_ext;
+
+ err = ext4_ext_get_access(handle, inode, path + depth);
+ if (err)
+ goto out;
+ /* first mark the extent as initialized */
+ ext4_ext_mark_initialized(ex);
+
+ /*
+ * We have to see if it can be merged with the extent
+ * on the left.
+ */
+ if (ex > EXT_FIRST_EXTENT(eh)) {
+ /*
+ * To merge left, pass "ex - 1" to try_to_merge(),
+ * since it merges towards right _only_.
+ */
+ ret = ext4_ext_try_to_merge(inode, path, ex - 1);
+ if (ret) {
+ err = ext4_ext_correct_indexes(handle, inode, path);
+ if (err)
+ goto out;
+ depth = ext_depth(inode);
+ ex--;
+ }
+ }
+ /*
+ * Try to Merge towards right.
+ */
+ ret = ext4_ext_try_to_merge(inode, path, ex);
+ if (ret) {
+ err = ext4_ext_correct_indexes(handle, inode, path);
+ if (err)
+ goto out;
+ depth = ext_depth(inode);
+ }
+ /* Mark modified extent as dirty */
+ err = ext4_ext_dirty(handle, inode, path + depth);
+out:
+ ext4_ext_show_leaf(inode, path);
+ return err;
+}
+
+static int
+ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
+ ext4_lblk_t iblock, unsigned int max_blocks,
+ struct ext4_ext_path *path, int flags,
+ unsigned int allocated, struct buffer_head *bh_result,
+ ext4_fsblk_t newblock)
+{
+ int ret = 0;
+ int err = 0;
+ ext4_io_end_t *io = EXT4_I(inode)->cur_aio_dio;
+
+ ext_debug("ext4_ext_handle_uninitialized_extents: inode %lu, logical"
+ "block %llu, max_blocks %u, flags %d, allocated %u",
+ inode->i_ino, (unsigned long long)iblock, max_blocks,
+ flags, allocated);
+ ext4_ext_show_leaf(inode, path);
+
+ /* DIO get_block() before submit the IO, split the extent */
+ if (flags == EXT4_GET_BLOCKS_DIO_CREATE_EXT) {
+ ret = ext4_split_unwritten_extents(handle,
+ inode, path, iblock,
+ max_blocks, flags);
+ /*
+ * Flag the inode(non aio case) or end_io struct (aio case)
+ * that this IO needs to convertion to written when IO is
+ * completed
+ */
+ if (io)
+ io->flag = DIO_AIO_UNWRITTEN;
+ else
+ EXT4_I(inode)->i_state |= EXT4_STATE_DIO_UNWRITTEN;
+ goto out;
+ }
+ /* async DIO end_io complete, convert the filled extent to written */
+ if (flags == EXT4_GET_BLOCKS_DIO_CONVERT_EXT) {
+ ret = ext4_convert_unwritten_extents_dio(handle, inode,
+ path);
+ goto out2;
+ }
+ /* buffered IO case */
+ /*
+ * repeat fallocate creation request
+ * we already have an unwritten extent
+ */
+ if (flags & EXT4_GET_BLOCKS_UNINIT_EXT)
+ goto map_out;
+
+ /* buffered READ or buffered write_begin() lookup */
+ if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
+ /*
+ * We have blocks reserved already. We
+ * return allocated blocks so that delalloc
+ * won't do block reservation for us. But
+ * the buffer head will be unmapped so that
+ * a read from the block returns 0s.
+ */
+ set_buffer_unwritten(bh_result);
+ goto out1;
+ }
+
+ /* buffered write, writepage time, convert*/
+ ret = ext4_ext_convert_to_initialized(handle, inode,
+ path, iblock,
+ max_blocks);
+out:
+ if (ret <= 0) {
+ err = ret;
+ goto out2;
+ } else
+ allocated = ret;
+ set_buffer_new(bh_result);
+map_out:
+ set_buffer_mapped(bh_result);
+out1:
+ if (allocated > max_blocks)
+ allocated = max_blocks;
+ ext4_ext_show_leaf(inode, path);
+ bh_result->b_bdev = inode->i_sb->s_bdev;
+ bh_result->b_blocknr = newblock;
+out2:
+ if (path) {
+ ext4_ext_drop_refs(path);
+ kfree(path);
+ }
+ return err ? err : allocated;
+}
+/*
+ * Block allocation/map/preallocation routine for extents based files
+ *
+ *
+ * Need to be called with
+ * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
+ * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
+ *
+ * return > 0, number of of blocks already mapped/allocated
+ * if create == 0 and these are pre-allocated blocks
+ * buffer head is unmapped
+ * otherwise blocks are mapped
+ *
+ * return = 0, if plain look up failed (blocks have not been allocated)
+ * buffer head is unmapped
+ *
+ * return < 0, error case.
+ */
+int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
+ ext4_lblk_t iblock,
+ unsigned int max_blocks, struct buffer_head *bh_result,
+ int flags)
+{
+ struct ext4_ext_path *path = NULL;
+ struct ext4_extent_header *eh;
+ struct ext4_extent newex, *ex;
+ ext4_fsblk_t newblock;
+ int err = 0, depth, ret, cache_type;
+ unsigned int allocated = 0;
+ struct ext4_allocation_request ar;
+ ext4_io_end_t *io = EXT4_I(inode)->cur_aio_dio;
+
+ __clear_bit(BH_New, &bh_result->b_state);
+ ext_debug("blocks %u/%u requested for inode %lu\n",
+ iblock, max_blocks, inode->i_ino);
+
+ /* check in cache */
+ cache_type = ext4_ext_in_cache(inode, iblock, &newex);
+ if (cache_type) {
+ if (cache_type == EXT4_EXT_CACHE_GAP) {
+ if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
+ /*
+ * block isn't allocated yet and
+ * user doesn't want to allocate it
+ */
+ goto out2;
+ }
+ /* we should allocate requested block */
+ } else if (cache_type == EXT4_EXT_CACHE_EXTENT) {
+ /* block is already allocated */
+ newblock = iblock
+ - le32_to_cpu(newex.ee_block)
+ + ext_pblock(&newex);
+ /* number of remaining blocks in the extent */
+ allocated = ext4_ext_get_actual_len(&newex) -
+ (iblock - le32_to_cpu(newex.ee_block));
+ goto out;
+ } else {
+ BUG();
+ }
+ }
+
+ /* find extent for this block */
+ path = ext4_ext_find_extent(inode, iblock, NULL);
+ if (IS_ERR(path)) {
+ err = PTR_ERR(path);
+ path = NULL;
+ goto out2;
+ }
+
+ depth = ext_depth(inode);
+
+ /*
+ * consistent leaf must not be empty;
+ * this situation is possible, though, _during_ tree modification;
+ * this is why assert can't be put in ext4_ext_find_extent()
+ */
+ BUG_ON(path[depth].p_ext == NULL && depth != 0);
+ eh = path[depth].p_hdr;
+
+ ex = path[depth].p_ext;
+ if (ex) {
+ ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
+ ext4_fsblk_t ee_start = ext_pblock(ex);
+ unsigned short ee_len;
+
+ /*
+ * Uninitialized extents are treated as holes, except that