Viewing: ext4-kill-dx-root.patch
commit 24f463435bea176b9139d9ac51315784beae0023
Author: Pravin Shelar <Pravin.Shelar@sun.com>
AuthorDate: Sun Oct 4 18:05:00 2009 +0000
LU-11922 ldiskfs: add "FID in dirent" support in ext4
Split monolithic definition of dx_root struct to separate dx_root_info
from fake struct ext4_dir_entry2 for improved code readability.
This allows "." and ".." dirents to have different sizes if necessary,
since we can't assume the rec_len 12 if dx_root dirents have dirdata.
Adds dx_get_dx_info() accessor instead of complex typecast at callers.
Does not change any functionality.
Bugzilla-ID: b=17670
Signed-off-by: Bob Glossman <bob.glossman@intel.com>
Signed-off-by: Yang Sheng <yang.sheng@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Change-Id: Ifbc294a53bd21eb35d373637d3326fc3c611c9f0
Reviewed-on: http://review.whamcloud.com/10249
---
fs/ext4/namei.c | 111 +++++++++++++++++++++++++-----------------------
1 file changed, 58 insertions(+), 53 deletions(-)
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index a1db7ce..b0291ed 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -212,22 +212,13 @@ struct dx_entry
* hash version mod 4 should never be 0. Sincerely, the paranoia department.
*/
-struct dx_root
+struct dx_root_info
{
- struct fake_dirent dot;
- char dot_name[4];
- struct fake_dirent dotdot;
- char dotdot_name[4];
- struct dx_root_info
- {
- __le32 reserved_zero;
- u8 hash_version;
- u8 info_length; /* 8 */
- u8 indirect_levels;
- u8 unused_flags;
- }
- info;
- struct dx_entry entries[0];
+ __le32 reserved_zero;
+ u8 hash_version;
+ u8 info_length; /* 8 */
+ u8 indirect_levels;
+ u8 unused_flags;
};
struct dx_node
@@ -529,6 +520,16 @@ ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
* Future: use high four bits of block for coalesce-on-delete flags
* Mask them off for now.
*/
+struct dx_root_info *dx_get_dx_info(struct ext4_dir_entry_2 *de)
+{
+ /* get dotdot first */
+ de = (struct ext4_dir_entry_2 *)((char *)de + EXT4_DIR_REC_LEN(1));
+
+ /* dx root info is after dotdot entry */
+ de = (struct ext4_dir_entry_2 *)((char *)de + EXT4_DIR_REC_LEN(2));
+
+ return (struct dx_root_info *)de;
+}
static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
{
@@ -753,7 +754,7 @@ dx_probe(struct ext4_filename *fname, struct inode *dir,
{
unsigned count, indirect;
struct dx_entry *at, *entries, *p, *q, *m;
- struct dx_root *root;
+ struct dx_root_info *info;
struct dx_frame *frame = frame_in;
struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
u32 hash;
@@ -762,18 +763,17 @@ dx_probe(struct ext4_filename *fname, struct inode *dir,
frame->bh = ext4_read_dirblock(dir, 0, INDEX);
if (IS_ERR(frame->bh))
return (struct dx_frame *) frame->bh;
-
- root = (struct dx_root *) frame->bh->b_data;
- if (root->info.hash_version != DX_HASH_TEA &&
- root->info.hash_version != DX_HASH_HALF_MD4 &&
- root->info.hash_version != DX_HASH_LEGACY) {
- ext4_warning_inode(dir, "Unrecognised inode hash code %u for directory "
- "%lu", root->info.hash_version, dir->i_ino);
+ info = dx_get_dx_info((struct ext4_dir_entry_2 *)frame->bh->b_data);
+ if (info->hash_version != DX_HASH_TEA &&
+ info->hash_version != DX_HASH_HALF_MD4 &&
+ info->hash_version != DX_HASH_LEGACY) {
+ ext4_warning(dir->i_sb, "Unrecognised inode hash code %d for directory "
+ "#%lu", info->hash_version, dir->i_ino);
goto fail;
}
if (fname)
hinfo = &fname->hinfo;
- hinfo->hash_version = root->info.hash_version;
+ hinfo->hash_version = info->hash_version;
if (hinfo->hash_version <= DX_HASH_TEA)
hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
@@ -781,13 +781,13 @@ dx_probe(struct ext4_filename *fname, struct inode *dir,
ext4fs_dirhash(dir, fname_name(fname), fname_len(fname), hinfo);
hash = hinfo->hash;
- if (root->info.unused_flags & 1) {
+ if (info->unused_flags & 1) {
ext4_warning_inode(dir, "Unimplemented hash flags: %#06x",
- root->info.unused_flags);
+ info->unused_flags);
goto fail;
}
- indirect = root->info.indirect_levels;
+ indirect = info->indirect_levels;
if (indirect >= ext4_dir_htree_level(dir->i_sb)) {
ext4_warning(dir->i_sb,
"Directory (ino: %lu) htree depth %#06x exceed"
@@ -800,14 +800,13 @@ dx_probe(struct ext4_filename *fname, struct inode *dir,
goto fail;
}
- entries = (struct dx_entry *)(((char *)&root->info) +
- root->info.info_length);
+ entries = (struct dx_entry *)(((char *)info) + info->info_length);
if (dx_get_limit(entries) != dx_root_limit(dir,
- root->info.info_length)) {
+ info->info_length)) {
ext4_warning_inode(dir, "dx entry: limit %u != root limit %u",
dx_get_limit(entries),
- dx_root_limit(dir, root->info.info_length));
+ dx_root_limit(dir, info->info_length));
goto fail;
}
@@ -892,7 +891,7 @@ static void dx_release(struct dx_frame *frames)
if (frames[0].bh == NULL)
return;
- info = &((struct dx_root *)frames[0].bh->b_data)->info;
+ info = dx_get_dx_info((struct ext4_dir_entry_2 *)frames[0].bh->b_data);
/* save local copy, "info" may be freed after brelse() */
indirect_levels = info->indirect_levels;
for (i = 0; i <= indirect_levels; i++) {
@@ -2065,16 +2064,15 @@ static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
struct inode *inode, struct buffer_head *bh)
{
struct buffer_head *bh2;
- struct dx_root *root;
struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
struct dx_entry *entries;
- struct ext4_dir_entry_2 *de, *de2;
+ struct ext4_dir_entry_2 *de, *de2, *dot_de, *dotdot_de;
char *data2, *top;
unsigned len;
int retval;
unsigned blocksize;
ext4_lblk_t block;
- struct fake_dirent *fde;
+ struct dx_root_info *dx_info;
int csum_size = 0;
if (ext4_has_metadata_csum(inode->i_sb))
@@ -2089,18 +2087,19 @@ static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
brelse(bh);
return retval;
}
- root = (struct dx_root *) bh->b_data;
+
+ dot_de = (struct ext4_dir_entry_2 *)bh->b_data;
+ dotdot_de = ext4_next_entry(dot_de, blocksize);
/* The 0th block becomes the root, move the dirents out */
- fde = &root->dotdot;
- de = (struct ext4_dir_entry_2 *)((char *)fde +
- ext4_rec_len_from_disk(fde->rec_len, blocksize));
- if ((char *) de >= (((char *) root) + blocksize)) {
+ de = (struct ext4_dir_entry_2 *)((char *)dotdot_de +
+ ext4_rec_len_from_disk(dotdot_de->rec_len, blocksize));
+ if ((char *)de >= (((char *)dot_de) + blocksize)) {
EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
brelse(bh);
return -EFSCORRUPTED;
}
- len = ((char *) root) + (blocksize - csum_size) - (char *) de;
+ len = ((char *)dot_de) + (blocksize - csum_size) - (char *)de;
/* Allocate new block for the 0th block's dirents */
bh2 = ext4_append(handle, dir, &block);
@@ -2123,19 +2122,24 @@ static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
ext4_initialize_dirent_tail(bh2, blocksize);
/* Initialize the root; the dot dirents already exist */
- de = (struct ext4_dir_entry_2 *) (&root->dotdot);
- de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
- blocksize);
- memset (&root->info, 0, sizeof(root->info));
- root->info.info_length = sizeof(root->info);
- root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
- entries = root->entries;
+ dotdot_de->rec_len =
+ ext4_rec_len_to_disk(blocksize - le16_to_cpu(dot_de->rec_len),
+ blocksize);
+
+ /* initialize hashing info */
+ dx_info = dx_get_dx_info(dot_de);
+ memset(dx_info, 0, sizeof(*dx_info));
+ dx_info->info_length = sizeof(*dx_info);
+ dx_info->hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
+
+ entries = (void *)dx_info + sizeof(*dx_info);
+
dx_set_block(entries, 1);
dx_set_count(entries, 1);
- dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
+ dx_set_limit(entries, dx_root_limit(dir, sizeof(*dx_info)));
/* Initialize as for dx_probe */
- fname->hinfo.hash_version = root->info.hash_version;
+ fname->hinfo.hash_version = dx_info->hash_version;
if (fname->hinfo.hash_version <= DX_HASH_TEA)
fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
@@ -2488,7 +2492,7 @@ again:
goto journal_error;
}
} else {
- struct dx_root *dxroot;
+ struct dx_root_info *info;
memcpy((char *) entries2, (char *) entries,
icount * sizeof(struct dx_entry));
dx_set_limit(entries2, dx_node_limit(dir));
@@ -2496,8 +2500,9 @@ again:
/* Set up root */
dx_set_count(entries, 1);
dx_set_block(entries + 0, newblock);
- dxroot = (struct dx_root *)frames[0].bh->b_data;
- dxroot->info.indirect_levels += 1;
+ info = dx_get_dx_info((struct ext4_dir_entry_2 *)
+ frames[0].bh->b_data);
+ info->indirect_levels += 1;
dxtrace(printk(KERN_DEBUG
"Creating %d level index...\n",
dxroot->info.indirect_levels));
--
2.20.1
