From 1939dd84b3f52e9c8d1b46dffae2058f16a3ff6a Mon Sep 17 00:00:00 2001 From: Dmitry Monakhov Date: Sat, 22 Oct 2011 01:26:05 -0400 Subject: [PATCH] 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 Signed-off-by: "Theodore Ts'o" --- fs/ext4/extents.c | 41 +++++++++++++++-------------------------- 1 file changed, 15 insertions(+), 26 deletions(-) diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 2fc6cc0..385ebb4 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -1050,16 +1050,14 @@ cleanup: */ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode, unsigned int flags, - struct ext4_ext_path *path, struct ext4_extent *newext) { - struct ext4_ext_path *curp = path; struct ext4_extent_header *neh; struct buffer_head *bh; ext4_fsblk_t newblock; int err = 0; - newblock = ext4_ext_new_meta_block(handle, inode, path, + newblock = ext4_ext_new_meta_block(handle, inode, NULL, newext, &err, flags); if (newblock == 0) return err; @@ -1079,7 +1077,8 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode, } /* move top-level index/leaf into new block */ - memmove(bh->b_data, curp->p_hdr, sizeof(EXT4_I(inode)->i_data)); + memmove(bh->b_data, EXT4_I(inode)->i_data, + sizeof(EXT4_I(inode)->i_data)); /* set size of new block */ neh = ext_block_hdr(bh); @@ -1097,32 +1096,23 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode, if (err) goto out; - /* create index in new top-level index: num,max,pointer */ - err = ext4_ext_get_access(handle, inode, curp); - if (err) - goto out; - - curp->p_hdr->eh_magic = EXT4_EXT_MAGIC; - curp->p_hdr->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0)); - curp->p_hdr->eh_entries = cpu_to_le16(1); - curp->p_idx = EXT_FIRST_INDEX(curp->p_hdr); - - if (path[0].p_hdr->eh_depth) - curp->p_idx->ei_block = - EXT_FIRST_INDEX(path[0].p_hdr)->ei_block; - else - curp->p_idx->ei_block = - EXT_FIRST_EXTENT(path[0].p_hdr)->ee_block; - ext4_idx_store_pblock(curp->p_idx, newblock); - + /* Update top-level index: num,max,pointer */ neh = ext_inode_hdr(inode); + neh->eh_entries = cpu_to_le16(1); + ext4_idx_store_pblock(EXT_FIRST_INDEX(neh), newblock); + if (neh->eh_depth == 0) { + /* Root extent block becomes index block */ + neh->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0)); + EXT_FIRST_INDEX(neh)->ei_block = + EXT_FIRST_EXTENT(neh)->ee_block; + } ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n", le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max), le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block), ext4_idx_pblock(EXT_FIRST_INDEX(neh))); - neh->eh_depth = cpu_to_le16(path->p_depth + 1); - err = ext4_ext_dirty(handle, inode, curp); + neh->eh_depth = cpu_to_le16(neh->eh_depth + 1); + ext4_mark_inode_dirty(handle, inode); out: brelse(bh); @@ -1170,8 +1160,7 @@ repeat: err = PTR_ERR(path); } else { /* tree is full, time to grow in depth */ - err = ext4_ext_grow_indepth(handle, inode, flags, - path, newext); + err = ext4_ext_grow_indepth(handle, inode, flags, newext); if (err) goto out; -- 2.7.4