ext4: cleanup ext4_ext_grow_indepth code
Currently code make an impression what grow procedure is very complicated and some mythical paths, blocks are involved. But in fact grow in depth it relatively simple procedure: 1) Just create new meta block and copy root data to that block. 2) Convert root from extent to index if old depth == 0 3) Update root block pointer This patch does: - Reorganize code to make it more self explanatory - Do not pass path parameter to new_meta_block() in order to provoke allocation from inode's group because top-level block should site closer to it's inode, but not to leaf data block. [ This happens anyway, due to logic in mballoc; we should drop the path parameter from new_meta_block() entirely. -- tytso ] Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
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45dc63e7d8
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1939dd84b3
1 changed files with 15 additions and 26 deletions
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@ -1050,16 +1050,14 @@ cleanup:
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*/
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static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
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unsigned int flags,
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struct ext4_ext_path *path,
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struct ext4_extent *newext)
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{
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struct ext4_ext_path *curp = path;
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struct ext4_extent_header *neh;
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struct buffer_head *bh;
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ext4_fsblk_t newblock;
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int err = 0;
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newblock = ext4_ext_new_meta_block(handle, inode, path,
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newblock = ext4_ext_new_meta_block(handle, inode, NULL,
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newext, &err, flags);
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if (newblock == 0)
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return err;
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@ -1079,7 +1077,8 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
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}
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/* move top-level index/leaf into new block */
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memmove(bh->b_data, curp->p_hdr, sizeof(EXT4_I(inode)->i_data));
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memmove(bh->b_data, EXT4_I(inode)->i_data,
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sizeof(EXT4_I(inode)->i_data));
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/* set size of new block */
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neh = ext_block_hdr(bh);
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@ -1097,32 +1096,23 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
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if (err)
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goto out;
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/* create index in new top-level index: num,max,pointer */
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err = ext4_ext_get_access(handle, inode, curp);
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if (err)
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goto out;
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curp->p_hdr->eh_magic = EXT4_EXT_MAGIC;
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curp->p_hdr->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0));
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curp->p_hdr->eh_entries = cpu_to_le16(1);
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curp->p_idx = EXT_FIRST_INDEX(curp->p_hdr);
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if (path[0].p_hdr->eh_depth)
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curp->p_idx->ei_block =
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EXT_FIRST_INDEX(path[0].p_hdr)->ei_block;
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else
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curp->p_idx->ei_block =
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EXT_FIRST_EXTENT(path[0].p_hdr)->ee_block;
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ext4_idx_store_pblock(curp->p_idx, newblock);
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/* Update top-level index: num,max,pointer */
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neh = ext_inode_hdr(inode);
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neh->eh_entries = cpu_to_le16(1);
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ext4_idx_store_pblock(EXT_FIRST_INDEX(neh), newblock);
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if (neh->eh_depth == 0) {
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/* Root extent block becomes index block */
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neh->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0));
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EXT_FIRST_INDEX(neh)->ei_block =
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EXT_FIRST_EXTENT(neh)->ee_block;
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}
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ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n",
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le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max),
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le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block),
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ext4_idx_pblock(EXT_FIRST_INDEX(neh)));
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neh->eh_depth = cpu_to_le16(path->p_depth + 1);
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err = ext4_ext_dirty(handle, inode, curp);
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neh->eh_depth = cpu_to_le16(neh->eh_depth + 1);
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ext4_mark_inode_dirty(handle, inode);
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out:
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brelse(bh);
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@ -1170,8 +1160,7 @@ repeat:
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err = PTR_ERR(path);
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} else {
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/* tree is full, time to grow in depth */
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err = ext4_ext_grow_indepth(handle, inode, flags,
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path, newext);
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err = ext4_ext_grow_indepth(handle, inode, flags, newext);
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if (err)
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goto out;
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