提交 1939dd84 编写于 作者: D Dmitry Monakhov 提交者: Theodore Ts'o

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: NDmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
上级 45dc63e7
...@@ -1050,16 +1050,14 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode, ...@@ -1050,16 +1050,14 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
*/ */
static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode, static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
unsigned int flags, unsigned int flags,
struct ext4_ext_path *path,
struct ext4_extent *newext) struct ext4_extent *newext)
{ {
struct ext4_ext_path *curp = path;
struct ext4_extent_header *neh; struct ext4_extent_header *neh;
struct buffer_head *bh; struct buffer_head *bh;
ext4_fsblk_t newblock; ext4_fsblk_t newblock;
int err = 0; int err = 0;
newblock = ext4_ext_new_meta_block(handle, inode, path, newblock = ext4_ext_new_meta_block(handle, inode, NULL,
newext, &err, flags); newext, &err, flags);
if (newblock == 0) if (newblock == 0)
return err; return err;
...@@ -1079,7 +1077,8 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode, ...@@ -1079,7 +1077,8 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
} }
/* move top-level index/leaf into new block */ /* 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 */ /* set size of new block */
neh = ext_block_hdr(bh); neh = ext_block_hdr(bh);
...@@ -1097,32 +1096,23 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode, ...@@ -1097,32 +1096,23 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
if (err) if (err)
goto out; goto out;
/* create index in new top-level index: num,max,pointer */ /* Update 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);
neh = ext_inode_hdr(inode); 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", ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n",
le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max), le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max),
le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block), le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block),
ext4_idx_pblock(EXT_FIRST_INDEX(neh))); ext4_idx_pblock(EXT_FIRST_INDEX(neh)));
neh->eh_depth = cpu_to_le16(path->p_depth + 1); neh->eh_depth = cpu_to_le16(neh->eh_depth + 1);
err = ext4_ext_dirty(handle, inode, curp); ext4_mark_inode_dirty(handle, inode);
out: out:
brelse(bh); brelse(bh);
...@@ -1170,8 +1160,7 @@ static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode, ...@@ -1170,8 +1160,7 @@ static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
err = PTR_ERR(path); err = PTR_ERR(path);
} else { } else {
/* tree is full, time to grow in depth */ /* tree is full, time to grow in depth */
err = ext4_ext_grow_indepth(handle, inode, flags, err = ext4_ext_grow_indepth(handle, inode, flags, newext);
path, newext);
if (err) if (err)
goto out; goto out;
......
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