--- /dev/null
+Subject: [PATCH] This patch implements feature which allows ext4 fs users
+ (e.g. Lustre) to store data in ext4 dirent.
+
+Data is stored in ext4 dirent after file-name, this space is accounted
+in de->rec_len. Flag EXT4_DIRENT_LUFID is added to d_type when extra
+data is present.
+
+This uses dentry->d_fsdata to pass fid to ext4. so no
+changes in ext4_add_entry() interface required.
+---
+ fs/ext4/dir.c | 14 ++--
+ fs/ext4/ext4.h | 97 +++++++++++++++++++++--
+ fs/ext4/inline.c | 8 +-
+ fs/ext4/namei.c | 200 +++++++++++++++++++++++++++++++++++++----------
+ fs/ext4/super.c | 4 +-
+ 5 files changed, 267 insertions(+), 56 deletions(-)
+
+diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
+index 0589e91..6db6302 100644
+--- a/fs/ext4/dir.c
++++ b/fs/ext4/dir.c
+@@ -77,7 +77,7 @@ int __ext4_check_dir_entry(const char *function, unsigned int line,
+ error_msg = "rec_len is smaller than minimal";
+ else if (unlikely(rlen % 4 != 0))
+ error_msg = "rec_len % 4 != 0";
+- else if (unlikely(rlen < EXT4_DIR_REC_LEN(de->name_len)))
++ else if (unlikely(rlen < EXT4_DIR_ENTRY_LEN(de)))
+ error_msg = "rec_len is too small for name_len";
+ else if (unlikely(((char *) de - buf) + rlen > size))
+ error_msg = "directory entry overrun";
+@@ -227,7 +227,7 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx)
+ * failure will be detected in the
+ * dirent test below. */
+ if (ext4_rec_len_from_disk(de->rec_len,
+- sb->s_blocksize) < EXT4_DIR_REC_LEN(1))
++ sb->s_blocksize) < EXT4_DIR_REC_LEN(1))
+ break;
+ i += ext4_rec_len_from_disk(de->rec_len,
+ sb->s_blocksize);
+@@ -414,7 +414,6 @@ static void free_rb_tree_fname(struct rb_root *root)
+ *root = RB_ROOT;
+ }
+
+-
+ static struct dir_private_info *ext4_htree_create_dir_info(struct file *filp,
+ loff_t pos)
+ {
+@@ -450,12 +449,17 @@ int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
+ struct fname *fname, *new_fn;
+ struct dir_private_info *info;
+ int len;
++ int extra_data = 0;
+
+ info = dir_file->private_data;
+ p = &info->root.rb_node;
+
+ /* Create and allocate the fname structure */
+- len = sizeof(struct fname) + ent_name->len + 1;
++ if (dirent->file_type & EXT4_DIRENT_LUFID)
++ extra_data = ext4_get_dirent_data_len(dirent);
++
++ len = sizeof(struct fname) + ent_name->len + extra_data + 1;
++
+ new_fn = kzalloc(len, GFP_KERNEL);
+ if (!new_fn)
+ return -ENOMEM;
+@@ -464,7 +468,7 @@ int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
+ new_fn->inode = le32_to_cpu(dirent->inode);
+ new_fn->name_len = ent_name->len;
+ new_fn->file_type = dirent->file_type;
+- memcpy(new_fn->name, ent_name->name, ent_name->len);
++ memcpy(new_fn->name, ent_name->name, ent_name->len + extra_data);
+ new_fn->name[ent_name->len] = 0;
+
+ while (*p) {
+diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
+index 8577b51..dab4486 100644
+--- a/fs/ext4/ext4.h
++++ b/fs/ext4/ext4.h
+@@ -1088,6 +1088,7 @@ struct ext4_inode_info {
+ __u32 i_csum_seed;
+
+ kprojid_t i_projid;
++ void *i_dirdata;
+ };
+
+ /*
+@@ -1131,6 +1132,7 @@ struct ext4_inode_info {
+ #define EXT4_MOUNT_POSIX_ACL 0x08000 /* POSIX Access Control Lists */
+ #define EXT4_MOUNT_NO_AUTO_DA_ALLOC 0x10000 /* No auto delalloc mapping */
+ #define EXT4_MOUNT_BARRIER 0x20000 /* Use block barriers */
++#define EXT4_MOUNT_DIRDATA 0x60000 /* Data in directory entries*/
+ #define EXT4_MOUNT_QUOTA 0x40000 /* Some quota option set */
+ #define EXT4_MOUNT_USRQUOTA 0x80000 /* "old" user quota,
+ * enable enforcement for hidden
+@@ -1845,6 +1847,7 @@ EXT4_FEATURE_INCOMPAT_FUNCS(casefold, CASEFOLD)
+ EXT4_FEATURE_INCOMPAT_FLEX_BG| \
+ EXT4_FEATURE_INCOMPAT_EA_INODE| \
+ EXT4_FEATURE_INCOMPAT_MMP | \
++ EXT4_FEATURE_INCOMPAT_DIRDATA| \
+ EXT4_FEATURE_INCOMPAT_INLINE_DATA | \
+ EXT4_FEATURE_INCOMPAT_ENCRYPT | \
+ EXT4_FEATURE_INCOMPAT_CASEFOLD | \
+@@ -2022,6 +2025,43 @@ struct ext4_dir_entry_tail {
+ #define EXT4_FT_SYMLINK 7
+
+ #define EXT4_FT_MAX 8
++#define EXT4_FT_MASK 0xf
++
++#if EXT4_FT_MAX > EXT4_FT_MASK
++#error "conflicting EXT4_FT_MAX and EXT4_FT_MASK"
++#endif
++
++/*
++ * d_type has 4 unused bits, so it can hold four types data. these different
++ * type of data (e.g. lustre data, high 32 bits of 64-bit inode number) can be
++ * stored, in flag order, after file-name in ext4 dirent.
++*/
++/*
++ * this flag is added to d_type if ext4 dirent has extra data after
++ * filename. this data length is variable and length is stored in first byte
++ * of data. data start after filename NUL byte.
++ * This is used by Lustre FS.
++ */
++#define EXT4_DIRENT_LUFID 0x10
++
++#define EXT4_LUFID_MAGIC 0xAD200907UL
++struct ext4_dentry_param {
++ __u32 edp_magic; /* EXT4_LUFID_MAGIC */
++ char edp_len; /* size of edp_data in bytes */
++ char edp_data[0]; /* packed array of data */
++} __packed;
++
++static inline unsigned char *ext4_dentry_get_data(struct super_block *sb,
++ struct ext4_dentry_param *p)
++
++{
++ if (!ext4_has_feature_dirdata(sb))
++ return NULL;
++ if (p && p->edp_magic == EXT4_LUFID_MAGIC)
++ return &p->edp_len;
++ else
++ return NULL;
++}
+
+ #define EXT4_FT_DIR_CSUM 0xDE
+
+@@ -2032,8 +2072,16 @@ struct ext4_dir_entry_tail {
+ */
+ #define EXT4_DIR_PAD 4
+ #define EXT4_DIR_ROUND (EXT4_DIR_PAD - 1)
+-#define EXT4_DIR_REC_LEN(name_len) (((name_len) + 8 + EXT4_DIR_ROUND) & \
++#define EXT4_DIR_REC_LEN_(name_len) (((name_len) + 8 + EXT4_DIR_ROUND) & \
+ ~EXT4_DIR_ROUND)
++#define EXT4_DIR_ENTRY_LEN_(de) (EXT4_DIR_REC_LEN_((de)->name_len +\
++ ext4_get_dirent_data_len(de)))
++/* ldiskfs */
++#define EXT4_DIR_REC_LEN(name_len) EXT4_DIR_REC_LEN_((name_len))
++#define EXT4_DIR_ENTRY_LEN(de) EXT4_DIR_ENTRY_LEN_((de))
++/* lustre osd_handler compat */
++#define __EXT4_DIR_REC_LEN(name_len) EXT4_DIR_REC_LEN_((name_len))
++
+ #define EXT4_MAX_REC_LEN ((1<<16)-1)
+
+ /*
+@@ -2493,11 +2541,11 @@ extern int ext4_find_dest_de(struct inode *dir, struct inode *inode,
+ struct buffer_head *bh,
+ void *buf, int buf_size,
+ struct ext4_filename *fname,
+- struct ext4_dir_entry_2 **dest_de);
++ struct ext4_dir_entry_2 **dest_de, int *dlen);
+ void ext4_insert_dentry(struct inode *inode,
+ struct ext4_dir_entry_2 *de,
+ int buf_size,
+- struct ext4_filename *fname);
++ struct ext4_filename *fname, void *data);
+ static inline void ext4_update_dx_flag(struct inode *inode)
+ {
+ if (!ext4_has_feature_dir_index(inode->i_sb) &&
+@@ -2513,10 +2561,17 @@ static const unsigned char ext4_filetype_table[] = {
+
+ static inline unsigned char get_dtype(struct super_block *sb, int filetype)
+ {
+- if (!ext4_has_feature_filetype(sb) || filetype >= EXT4_FT_MAX)
++ int fl_index = filetype & EXT4_FT_MASK;
++
++ if (!ext4_has_feature_filetype(sb) || fl_index >= EXT4_FT_MAX)
+ return DT_UNKNOWN;
+
+- return ext4_filetype_table[filetype];
++ if (!test_opt(sb, DIRDATA))
++ return ext4_filetype_table[fl_index];
++
++ return (ext4_filetype_table[fl_index]) |
++ (filetype & EXT4_DIRENT_LUFID);
++
+ }
+ extern int ext4_check_all_de(struct inode *dir, struct buffer_head *bh,
+ void *buf, int buf_size);
+@@ -2679,6 +2734,8 @@ extern struct inode *ext4_create_inode(handle_t *handle,
+ extern int ext4_delete_entry(handle_t *handle, struct inode * dir,
+ struct ext4_dir_entry_2 *de_del,
+ struct buffer_head *bh);
++extern int ext4_add_dot_dotdot(handle_t *handle, struct inode *dir,
++ struct inode *inode, const void *, const void *);
+ extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
+ __u32 start_minor_hash, __u32 *next_hash);
+ extern int ext4_search_dir(struct buffer_head *bh,
+@@ -3414,6 +3471,36 @@ static inline void ext4_clear_io_unwritten_flag(ext4_io_end_t *io_end)
+
+ extern const struct iomap_ops ext4_iomap_ops;
+
++/*
++ * Compute the total directory entry data length.
++ * This includes the filename and an implicit NUL terminator (always present),
++ * and optional extensions. Each extension has a bit set in the high 4 bits of
++ * de->file_type, and the extension length is the first byte in each entry.
++ */
++static inline int ext4_get_dirent_data_len(struct ext4_dir_entry_2 *de)
++{
++ char *len = de->name + de->name_len + 1 /* NUL terminator */;
++ int dlen = 0;
++ __u8 extra_data_flags = (de->file_type & ~EXT4_FT_MASK) >> 4;
++ struct ext4_dir_entry_tail *t = (struct ext4_dir_entry_tail *)de;
++
++ if (!t->det_reserved_zero1 &&
++ le16_to_cpu(t->det_rec_len) ==
++ sizeof(struct ext4_dir_entry_tail) &&
++ !t->det_reserved_zero2 &&
++ t->det_reserved_ft == EXT4_FT_DIR_CSUM)
++ return 0;
++
++ while (extra_data_flags) {
++ if (extra_data_flags & 1) {
++ dlen += *len + (dlen == 0);
++ len += *len;
++ }
++ extra_data_flags >>= 1;
++ }
++ return dlen;
++}
++
+ #endif /* __KERNEL__ */
+
+ #define EFSBADCRC EBADMSG /* Bad CRC detected */
+diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
+index 46151bd..316892b 100644
+--- a/fs/ext4/inline.c
++++ b/fs/ext4/inline.c
+@@ -1029,7 +1029,7 @@ static int ext4_add_dirent_to_inline(handle_t *handle,
+ struct ext4_dir_entry_2 *de;
+
+ err = ext4_find_dest_de(dir, inode, iloc->bh, inline_start,
+- inline_size, fname, &de);
++ inline_size, fname, &de, NULL);
+ if (err)
+ return err;
+
+@@ -1037,7 +1037,7 @@ static int ext4_add_dirent_to_inline(handle_t *handle,
+ err = ext4_journal_get_write_access(handle, iloc->bh);
+ if (err)
+ return err;
+- ext4_insert_dentry(inode, de, inline_size, fname);
++ ext4_insert_dentry(inode, de, inline_size, fname, NULL);
+
+ ext4_show_inline_dir(dir, iloc->bh, inline_start, inline_size);
+
+@@ -1384,7 +1384,7 @@ int ext4_inlinedir_to_tree(struct file *dir_file,
+ fake.name_len = 1;
+ strcpy(fake.name, ".");
+ fake.rec_len = ext4_rec_len_to_disk(
+- EXT4_DIR_REC_LEN(fake.name_len),
++ EXT4_DIR_ENTRY_LEN(&fake),
+ inline_size);
+ ext4_set_de_type(inode->i_sb, &fake, S_IFDIR);
+ de = &fake;
+@@ -1394,7 +1394,7 @@ int ext4_inlinedir_to_tree(struct file *dir_file,
+ fake.name_len = 2;
+ strcpy(fake.name, "..");
+ fake.rec_len = ext4_rec_len_to_disk(
+- EXT4_DIR_REC_LEN(fake.name_len),
++ EXT4_DIR_ENTRY_LEN(&fake),
+ inline_size);
+ ext4_set_de_type(inode->i_sb, &fake, S_IFDIR);
+ de = &fake;
+diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
+index 54cca61..2bc4682 100644
+--- a/fs/ext4/namei.c
++++ b/fs/ext4/namei.c
+@@ -258,7 +258,8 @@ static unsigned dx_get_count(struct dx_entry *entries);
+ static unsigned dx_get_limit(struct dx_entry *entries);
+ static void dx_set_count(struct dx_entry *entries, unsigned value);
+ static void dx_set_limit(struct dx_entry *entries, unsigned value);
+-static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
++static inline unsigned dx_root_limit(struct inode *dir,
++ struct ext4_dir_entry_2 *dot_de, unsigned infosize);
+ static unsigned dx_node_limit(struct inode *dir);
+ static struct dx_frame *dx_probe(struct ext4_filename *fname,
+ struct inode *dir,
+@@ -402,22 +403,23 @@ static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
+ {
+ struct ext4_dir_entry *dp;
+ struct dx_root_info *root;
+- int count_offset;
++ int count_offset, dot_rec_len, dotdot_rec_len;
+
+ if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
+ count_offset = 8;
+- else if (le16_to_cpu(dirent->rec_len) == 12) {
+- dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
++ else {
++ dot_rec_len = le16_to_cpu(dirent->rec_len);
++ dp = (struct ext4_dir_entry *)(((void *)dirent) + dot_rec_len);
+ if (le16_to_cpu(dp->rec_len) !=
+- EXT4_BLOCK_SIZE(inode->i_sb) - 12)
++ EXT4_BLOCK_SIZE(inode->i_sb) - dot_rec_len)
+ return NULL;
+- root = (struct dx_root_info *)(((void *)dp + 12));
++ dotdot_rec_len = EXT4_DIR_ENTRY_LEN((struct ext4_dir_entry_2 *)dp);
++ root = (struct dx_root_info *)(((void *)dp + dotdot_rec_len));
+ if (root->reserved_zero ||
+ root->info_length != sizeof(struct dx_root_info))
+ return NULL;
+- count_offset = 32;
+- } else
+- return NULL;
++ count_offset = 8 + dot_rec_len + dotdot_rec_len;
++ }
+
+ if (offset)
+ *offset = count_offset;
+@@ -522,11 +524,12 @@ ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
+ */
+ struct dx_root_info *dx_get_dx_info(struct ext4_dir_entry_2 *de)
+ {
++ BUG_ON(de->name_len != 1);
+ /* get dotdot first */
+- de = (struct ext4_dir_entry_2 *)((char *)de + EXT4_DIR_REC_LEN(1));
++ de = (struct ext4_dir_entry_2 *)((char *)de + EXT4_DIR_ENTRY_LEN(de));
+
+ /* dx root info is after dotdot entry */
+- de = (struct ext4_dir_entry_2 *)((char *)de + EXT4_DIR_REC_LEN(2));
++ de = (struct ext4_dir_entry_2 *)((char *)de + EXT4_DIR_ENTRY_LEN(de));
+
+ return (struct dx_root_info *)de;
+ }
+@@ -571,10 +574,16 @@ static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
+ ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
+ }
+
+-static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
++static inline unsigned dx_root_limit(struct inode *dir,
++ struct ext4_dir_entry_2 *dot_de, unsigned infosize)
+ {
+- unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
+- EXT4_DIR_REC_LEN(2) - infosize;
++ struct ext4_dir_entry_2 *dotdot_de;
++ unsigned entry_space;
++
++ BUG_ON(dot_de->name_len != 1);
++ dotdot_de = ext4_next_entry(dot_de, dir->i_sb->s_blocksize);
++ entry_space = dir->i_sb->s_blocksize - EXT4_DIR_ENTRY_LEN(dot_de) -
++ EXT4_DIR_ENTRY_LEN(dotdot_de) - infosize;
+
+ if (ext4_has_metadata_csum(dir->i_sb))
+ entry_space -= sizeof(struct dx_tail);
+@@ -695,7 +704,7 @@ static struct stats dx_show_leaf(struct inode *dir,
+ (unsigned) ((char *) de - base));
+ #endif
+ }
+- space += EXT4_DIR_REC_LEN(de->name_len);
++ space += EXT4_DIR_ENTRY_LEN(de);
+ names++;
+ }
+ de = ext4_next_entry(de, size);
+@@ -802,11 +811,14 @@ dx_probe(struct ext4_filename *fname, struct inode *dir,
+
+ entries = (struct dx_entry *)(((char *)info) + info->info_length);
+
+- if (dx_get_limit(entries) != dx_root_limit(dir,
+- info->info_length)) {
++ if (dx_get_limit(entries) !=
++ dx_root_limit(dir, (struct ext4_dir_entry_2 *)frame->bh->b_data,
++ info->info_length)) {
+ ext4_warning_inode(dir, "dx entry: limit %u != root limit %u",
+ dx_get_limit(entries),
+- dx_root_limit(dir, info->info_length));
++ dx_root_limit(dir,
++ (struct ext4_dir_entry_2 *)frame->bh->b_data,
++ info->info_length));
+ goto fail;
+ }
+
+@@ -1793,7 +1805,7 @@ dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
+ while (count--) {
+ struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
+ (from + (map->offs<<2));
+- rec_len = EXT4_DIR_REC_LEN(de->name_len);
++ rec_len = EXT4_DIR_ENTRY_LEN(de);
+ memcpy (to, de, rec_len);
+ ((struct ext4_dir_entry_2 *) to)->rec_len =
+ ext4_rec_len_to_disk(rec_len, blocksize);
+@@ -1817,7 +1829,7 @@ static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
+ while ((char*)de < base + blocksize) {
+ next = ext4_next_entry(de, blocksize);
+ if (de->inode && de->name_len) {
+- rec_len = EXT4_DIR_REC_LEN(de->name_len);
++ rec_len = EXT4_DIR_ENTRY_LEN(de);
+ if (de > to)
+ memmove(to, de, rec_len);
+ to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
+@@ -1954,14 +1966,16 @@ int ext4_find_dest_de(struct inode *dir, struct inode *inode,
+ struct buffer_head *bh,
+ void *buf, int buf_size,
+ struct ext4_filename *fname,
+- struct ext4_dir_entry_2 **dest_de)
++ struct ext4_dir_entry_2 **dest_de, int *dlen)
+ {
+ struct ext4_dir_entry_2 *de;
+- unsigned short reclen = EXT4_DIR_REC_LEN(fname_len(fname));
++ unsigned short reclen = EXT4_DIR_REC_LEN(fname_len(fname)) +
++ (dlen ? *dlen : 0);
+ int nlen, rlen;
+ unsigned int offset = 0;
+ char *top;
+
++ dlen ? *dlen = 0 : 0; /* default set to 0 */
+ de = (struct ext4_dir_entry_2 *)buf;
+ top = buf + buf_size - reclen;
+ while ((char *) de <= top) {
+@@ -1970,10 +1984,26 @@ int ext4_find_dest_de(struct inode *dir, struct inode *inode,
+ return -EFSCORRUPTED;
+ if (ext4_match(dir, fname, de))
+ return -EEXIST;
+- nlen = EXT4_DIR_REC_LEN(de->name_len);
++ nlen = EXT4_DIR_ENTRY_LEN(de);
+ rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
+ if ((de->inode ? rlen - nlen : rlen) >= reclen)
+ break;
++ /* Then for dotdot entries, check for the smaller space
++ * required for just the entry, no FID */
++ if (fname_len(fname) == 2 && memcmp(fname_name(fname), "..", 2) == 0) {
++ if ((de->inode ? rlen - nlen : rlen) >=
++ EXT4_DIR_REC_LEN(fname_len(fname))) {
++ /* set dlen=1 to indicate not
++ * enough space store fid */
++ dlen ? *dlen = 1 : 0;
++ break;
++ }
++ /* The new ".." entry must be written over the
++ * previous ".." entry, which is the first
++ * entry traversed by this scan. If it doesn't
++ * fit, something is badly wrong, so -EIO. */
++ return -EIO;
++ }
+ de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
+ offset += rlen;
+ }
+@@ -1987,12 +2017,12 @@ int ext4_find_dest_de(struct inode *dir, struct inode *inode,
+ void ext4_insert_dentry(struct inode *inode,
+ struct ext4_dir_entry_2 *de,
+ int buf_size,
+- struct ext4_filename *fname)
++ struct ext4_filename *fname, void *data)
+ {
+
+ int nlen, rlen;
+
+- nlen = EXT4_DIR_REC_LEN(de->name_len);
++ nlen = EXT4_DIR_ENTRY_LEN(de);
+ rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
+ if (de->inode) {
+ struct ext4_dir_entry_2 *de1 =
+@@ -2006,6 +2036,11 @@ void ext4_insert_dentry(struct inode *inode,
+ ext4_set_de_type(inode->i_sb, de, inode->i_mode);
+ de->name_len = fname_len(fname);
+ memcpy(de->name, fname_name(fname), fname_len(fname));
++ if (data) {
++ de->name[fname_len(fname)] = 0;
++ memcpy(&de->name[fname_len(fname) + 1], data, *(char *)data);
++ de->file_type |= EXT4_DIRENT_LUFID;
++ }
+ }
+
+ /*
+@@ -2022,15 +2057,21 @@ static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
+ struct buffer_head *bh)
+ {
+ unsigned int blocksize = dir->i_sb->s_blocksize;
++ int dlen = 0;
++ unsigned char *data;
+ int csum_size = 0;
+ int err;
+
++ data = ext4_dentry_get_data(inode->i_sb, (struct ext4_dentry_param *)
++ EXT4_I(inode)->i_dirdata);
+ if (ext4_has_metadata_csum(inode->i_sb))
+ csum_size = sizeof(struct ext4_dir_entry_tail);
+
+ if (!de) {
++ if (data)
++ dlen = (*data) + 1;
+ err = ext4_find_dest_de(dir, inode, bh, bh->b_data,
+- blocksize - csum_size, fname, &de);
++ blocksize - csum_size, fname, &de, &dlen);
+ if (err)
+ return err;
+ }
+@@ -2042,7 +2083,10 @@ static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
+ }
+
+ /* By now the buffer is marked for journaling */
+- ext4_insert_dentry(inode, de, blocksize, fname);
++ /* If writing the short form of "dotdot", don't add the data section */
++ if (dlen == 1)
++ data = NULL;
++ ext4_insert_dentry(inode, de, blocksize, fname, data);
+
+ /*
+ * XXX shouldn't update any times until successful
+@@ -2147,7 +2191,8 @@ static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
+
+ dx_set_block(entries, 1);
+ dx_set_count(entries, 1);
+- dx_set_limit(entries, dx_root_limit(dir, sizeof(*dx_info)));
++ dx_set_limit(entries, dx_root_limit(dir,
++ dot_de, sizeof(*dx_info)));
+
+ /* Initialize as for dx_probe */
+ fname->hinfo.hash_version = dx_info->hash_version;
+@@ -2197,6 +2242,8 @@ static int ext4_update_dotdot(handle_t *handle, struct dentry *dentry,
+ struct buffer_head *dir_block;
+ struct ext4_dir_entry_2 *de;
+ int len, journal = 0, err = 0;
++ int dlen = 0;
++ char *data;
+
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+@@ -2222,11 +2269,16 @@ static int ext4_update_dotdot(handle_t *handle, struct dentry *dentry,
+ goto out_journal;
+
+ journal = 1;
+- de->rec_len = cpu_to_le16(EXT4_DIR_REC_LEN(1));
++ de->rec_len = cpu_to_le16(EXT4_DIR_ENTRY_LEN(de));
+ }
+
+- len -= EXT4_DIR_REC_LEN(1);
+- assert(len == 0 || len >= EXT4_DIR_REC_LEN(2));
++ len -= EXT4_DIR_ENTRY_LEN(de);
++ data = ext4_dentry_get_data(dir->i_sb,
++ (struct ext4_dentry_param *)dentry->d_fsdata);
++ if (data)
++ dlen = *data + 1;
++ assert(len == 0 || len >= EXT4_DIR_REC_LEN(2 + dlen));
++
+ de = (struct ext4_dir_entry_2 *)
+ ((char *) de + le16_to_cpu(de->rec_len));
+ if (!journal) {
+@@ -2243,7 +2295,12 @@ static int ext4_update_dotdot(handle_t *handle, struct dentry *dentry,
+ assert(le16_to_cpu(de->rec_len) >= EXT4_DIR_REC_LEN(2));
+ de->name_len = 2;
+ strcpy(de->name, "..");
+- ext4_set_de_type(dir->i_sb, de, S_IFDIR);
++ if (data != NULL && ext4_get_dirent_data_len(de) >= dlen) {
++ de->name[2] = 0;
++ memcpy(&de->name[2 + 1], data, *data);
++ ext4_set_de_type(dir->i_sb, de, S_IFDIR);
++ de->file_type |= EXT4_DIRENT_LUFID;
++ }
+
+ out_journal:
+ if (journal) {
+@@ -2282,6 +2339,7 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
+ ext4_lblk_t block, blocks;
+ int csum_size = 0;
+
++ EXT4_I(inode)->i_dirdata = dentry->d_fsdata;
+ if (ext4_has_metadata_csum(inode->i_sb))
+ csum_size = sizeof(struct ext4_dir_entry_tail);
+
+@@ -2823,37 +2881,70 @@ err_unlock_inode:
+ return err;
+ }
+
++struct tp_block {
++ struct inode *inode;
++ void *data1;
++ void *data2;
++};
++
+ struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
+ struct ext4_dir_entry_2 *de,
+ int blocksize, int csum_size,
+ unsigned int parent_ino, int dotdot_real_len)
+ {
++ void *data1 = NULL, *data2 = NULL;
++ int dot_reclen = 0;
++
++ if (dotdot_real_len == 10) {
++ struct tp_block *tpb = (struct tp_block *)inode;
++ data1 = tpb->data1;
++ data2 = tpb->data2;
++ inode = tpb->inode;
++ dotdot_real_len = 0;
++ }
+ de->inode = cpu_to_le32(inode->i_ino);
+ de->name_len = 1;
+- de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
+- blocksize);
+ strcpy(de->name, ".");
+ ext4_set_de_type(inode->i_sb, de, S_IFDIR);
+
++ /* get packed fid data*/
++ data1 = ext4_dentry_get_data(inode->i_sb,
++ (struct ext4_dentry_param *) data1);
++ if (data1) {
++ de->name[1] = 0;
++ memcpy(&de->name[2], data1, *(char *) data1);
++ de->file_type |= EXT4_DIRENT_LUFID;
++ }
++ de->rec_len = cpu_to_le16(EXT4_DIR_ENTRY_LEN(de));
++ dot_reclen = cpu_to_le16(de->rec_len);
+ de = ext4_next_entry(de, blocksize);
+ de->inode = cpu_to_le32(parent_ino);
+ de->name_len = 2;
++ strcpy(de->name, "..");
++ ext4_set_de_type(inode->i_sb, de, S_IFDIR);
++ data2 = ext4_dentry_get_data(inode->i_sb,
++ (struct ext4_dentry_param *) data2);
++ if (data2) {
++ de->name[2] = 0;
++ memcpy(&de->name[3], data2, *(char *) data2);
++ de->file_type |= EXT4_DIRENT_LUFID;
++ }
+ if (!dotdot_real_len)
+ de->rec_len = ext4_rec_len_to_disk(blocksize -
+- (csum_size + EXT4_DIR_REC_LEN(1)),
++ (csum_size + dot_reclen),
+ blocksize);
+ else
+ de->rec_len = ext4_rec_len_to_disk(
+- EXT4_DIR_REC_LEN(de->name_len), blocksize);
+- strcpy(de->name, "..");
+- ext4_set_de_type(inode->i_sb, de, S_IFDIR);
++ EXT4_DIR_ENTRY_LEN(de), blocksize);
+
+ return ext4_next_entry(de, blocksize);
+ }
+
+ static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
+- struct inode *inode)
++ struct inode *inode,
++ const void *data1, const void *data2)
+ {
++ struct tp_block param;
+ struct buffer_head *dir_block = NULL;
+ struct ext4_dir_entry_2 *de;
+ ext4_lblk_t block = 0;
+@@ -2877,7 +2968,11 @@ static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
+ if (IS_ERR(dir_block))
+ return PTR_ERR(dir_block);
+ de = (struct ext4_dir_entry_2 *)dir_block->b_data;
+- ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
++ param.inode = inode;
++ param.data1 = (void *)data1;
++ param.data2 = (void *)data2;
++ ext4_init_dot_dotdot((struct inode *)(¶m), de, blocksize,
++ csum_size, dir->i_ino, 10);
+ set_nlink(inode, 2);
+ if (csum_size)
+ ext4_initialize_dirent_tail(dir_block, blocksize);
+@@ -2892,6 +2987,29 @@ out:
+ return err;
+ }
+
++/* Initialize @inode as a subdirectory of @dir, and add the
++ * "." and ".." entries into the first directory block. */
++int ext4_add_dot_dotdot(handle_t *handle, struct inode *dir,
++ struct inode *inode,
++ const void *data1, const void *data2)
++{
++ int rc;
++
++ if (IS_ERR(handle))
++ return PTR_ERR(handle);
++
++ if (IS_DIRSYNC(dir))
++ ext4_handle_sync(handle);
++
++ inode->i_op = &ext4_dir_inode_operations;
++ inode->i_fop = &ext4_dir_operations;
++ rc = ext4_init_new_dir(handle, dir, inode, data1, data2);
++ if (!rc)
++ rc = ext4_mark_inode_dirty(handle, inode);
++ return rc;
++}
++EXPORT_SYMBOL(ext4_add_dot_dotdot);
++
+ static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
+ {
+ handle_t *handle;
+@@ -2918,7 +3036,7 @@ retry:
+
+ inode->i_op = &ext4_dir_inode_operations;
+ inode->i_fop = &ext4_dir_operations;
+- err = ext4_init_new_dir(handle, dir, inode);
++ err = ext4_init_new_dir(handle, dir, inode, NULL, NULL);
+ if (err)
+ goto out_clear_inode;
+ err = ext4_mark_inode_dirty(handle, inode);
+diff --git a/fs/ext4/super.c b/fs/ext4/super.c
+index 9057a36..38310d3 100644
+--- a/fs/ext4/super.c
++++ b/fs/ext4/super.c
+@@ -1459,7 +1459,7 @@ enum {
+ Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
+ Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
+ Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
+- Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
++ Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err, Opt_dirdata,
+ Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version,
+ Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
+ Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
+@@ -1539,6 +1539,7 @@ static const match_table_t tokens = {
+ {Opt_nolazytime, "nolazytime"},
+ {Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
+ {Opt_nodelalloc, "nodelalloc"},
++ {Opt_dirdata, "dirdata"},
+ {Opt_removed, "mblk_io_submit"},
+ {Opt_removed, "nomblk_io_submit"},
+ {Opt_block_validity, "block_validity"},
+@@ -1769,6 +1770,7 @@ static const struct mount_opts {
+ {Opt_usrjquota, 0, MOPT_Q | MOPT_STRING},
+ {Opt_grpjquota, 0, MOPT_Q | MOPT_STRING},
+ {Opt_offusrjquota, 0, MOPT_Q},
++ {Opt_dirdata, EXT4_MOUNT_DIRDATA, MOPT_SET},
+ {Opt_offgrpjquota, 0, MOPT_Q},
+ {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
+ {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
+--
+2.30.2
+