--- /dev/null
+commit 2db3b2b33ee796f4ea61316773452d936303ad27
+Author: Pravin Shelar <Pravin.Shelar@sun.com>
+AuthorDate: Sun Oct 4 18:13:14 2009 +0000
+Subject: [PATCH] LU-11922 ldiskfs: make dirdata work with metadata_csum
+
+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: 17670
+Signed-off-by: Pravin Shelar <pravin.shelar@sun.com>
+Reviewed-by: Andreas Dilger <adilger@sun.com>
+Reviewed-by: Girish Shilamkar <girish.shilamkar@sun.com>
+---
+ fs/ext4/namei.c | 147 +++++++++++++++++++++++-------------------------
+ 1 file changed, 71 insertions(+), 76 deletions(-)
+
+diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
+index 015c801a..0bb519ab 100644
+--- a/fs/ext4/namei.c
++++ b/fs/ext4/namei.c
+@@ -245,22 +245,13 @@ 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[];
++ __le32 reserved_zero;
++ u8 hash_version;
++ u8 info_length; /* 8 */
++ u8 indirect_levels;
++ u8 unused_flags;
+ };
+
+ struct dx_node
+@@ -566,6 +557,16 @@ 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)
+ {
+@@ -813,7 +814,7 @@ dx_probe(struct ext4_filename *fname, struct inode *dir,
+ {
+ unsigned count, indirect, level, i;
+ 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;
+@@ -825,24 +826,24 @@ dx_probe(struct ext4_filename *fname, struct inode *dir,
+ 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 &&
+- root->info.hash_version != DX_HASH_SIPHASH) {
+- 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 &&
++ info->hash_version != DX_HASH_SIPHASH) {
++ ext4_warning(dir->i_sb,
++ "Unrecognised inode hash code %d for directory #%lu",
++ info->hash_version, dir->i_ino);
+ goto fail;
+ }
+ if (ext4_hash_in_dirent(dir)) {
+- if (root->info.hash_version != DX_HASH_SIPHASH) {
++ if (info->hash_version != DX_HASH_SIPHASH) {
+ ext4_warning_inode(dir,
+ "Hash in dirent, but hash is not SIPHASH");
+ goto fail;
+ }
+ } else {
+- if (root->info.hash_version == DX_HASH_SIPHASH) {
++ if (info->hash_version == DX_HASH_SIPHASH) {
+ ext4_warning_inode(dir,
+ "Hash code is SIPHASH, but hash not in dirent");
+ goto fail;
+@@ -850,7 +851,7 @@ dx_probe(struct ext4_filename *fname, struct inode *dir,
+ }
+ 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;
+@@ -866,13 +867,13 @@ dx_probe(struct ext4_filename *fname, struct inode *dir,
+ }
+ 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"
+@@ -885,14 +886,13 @@ 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;
+ }
+
+@@ -978,7 +978,7 @@ 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++) {
+@@ -2246,44 +2246,39 @@ static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
+ return err ? err : err2;
+ }
+
+-static bool ext4_check_dx_root(struct inode *dir, struct dx_root *root)
++static bool ext4_check_dx_root(struct inode *dir,
++ struct ext4_dir_entry_2 *dot_de,
++ struct ext4_dir_entry_2 *dotdot_de,
++ struct ext4_dir_entry_2 **entry)
+ {
+- struct fake_dirent *fde;
+ const char *error_msg;
+- unsigned int rlen;
+ unsigned int blocksize = dir->i_sb->s_blocksize;
+- char *blockend = (char *)root + dir->i_sb->s_blocksize;
++ struct ext4_dir_entry_2 *de = NULL;
+
+- fde = &root->dot;
+- if (unlikely(fde->name_len != 1)) {
++ if (unlikely(dot_de->name_len != 1)) {
+ error_msg = "invalid name_len for '.'";
+ goto corrupted;
+ }
+- if (unlikely(strncmp(root->dot_name, ".", fde->name_len))) {
++ if (unlikely(strncmp(dot_de->name, ".", dot_de->name_len))) {
+ error_msg = "invalid name for '.'";
+ goto corrupted;
+ }
+- rlen = ext4_rec_len_from_disk(fde->rec_len, blocksize);
+- if (unlikely((char *)fde + rlen >= blockend)) {
+- error_msg = "invalid rec_len for '.'";
+- goto corrupted;
+- }
+
+- fde = &root->dotdot;
+- if (unlikely(fde->name_len != 2)) {
++ if (unlikely(dotdot_de->name_len != 2)) {
+ error_msg = "invalid name_len for '..'";
+ goto corrupted;
+ }
+- if (unlikely(strncmp(root->dotdot_name, "..", fde->name_len))) {
++ if (unlikely(strncmp(dotdot_de->name, "..", dotdot_de->name_len))) {
+ error_msg = "invalid name for '..'";
+ goto corrupted;
+ }
+- rlen = ext4_rec_len_from_disk(fde->rec_len, blocksize);
+- if (unlikely((char *)fde + rlen >= blockend)) {
++ 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)) {
+ error_msg = "invalid rec_len for '..'";
+ goto corrupted;
+ }
+-
++ *entry = de;
+ return true;
+
+ corrupted:
+@@ -2301,16 +2296,15 @@ 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))
+@@ -2327,17 +2321,15 @@ static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
+ return retval;
+ }
+
+- root = (struct dx_root *) bh->b_data;
+- if (!ext4_check_dx_root(dir, root)) {
++ dot_de = (struct ext4_dir_entry_2 *)bh->b_data;
++ dotdot_de = ext4_next_entry(dot_de, blocksize);
++ if (!ext4_check_dx_root(dir, dot_de, dotdot_de, &de)) {
+ brelse(bh);
+ return -EFSCORRUPTED;
+ }
+
+ /* 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));
+- 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);
+@@ -2368,24 +2360,26 @@ 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, NULL), blocksize);
+- memset (&root->info, 0, sizeof(root->info));
+- root->info.info_length = sizeof(root->info);
++ 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);
+ if (ext4_hash_in_dirent(dir))
+- root->info.hash_version = DX_HASH_SIPHASH;
++ dx_info->hash_version = DX_HASH_SIPHASH;
+ else
+- root->info.hash_version =
++ dx_info->hash_version =
+ EXT4_SB(dir->i_sb)->s_def_hash_version;
+-
+- entries = root->entries;
++ 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;
+@@ -2751,7 +2745,7 @@ again:
+ if (restart || err)
+ 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));
+@@ -2759,8 +2753,9 @@ 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));
+--
+2.34.1
+
git://git.whamcloud.com / fs / lustre-release.git / commitdiff