1 this patch implements feature which allows ext4 fs users (e.g. Lustre)
2 to store data in ext4 dirent.
3 data is stored in ext4 dirent after file-name, this space is accounted
4 in de->rec_len. flag EXT4_DIRENT_LUFID added to d_type if extra data
7 make use of dentry->d_fsdata to pass fid to ext4. so no
8 changes in ext4_add_entry() interface required.
10 Index: linux-stage/fs/ext4/dir.c
11 ===================================================================
12 --- linux-stage.orig/fs/ext4/dir.c
13 +++ linux-stage/fs/ext4/dir.c
14 @@ -53,11 +53,18 @@ const struct file_operations ext4_dir_op
16 static unsigned char get_dtype(struct super_block *sb, int filetype)
18 + int fl_index = filetype & EXT4_FT_MASK;
20 if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE) ||
21 - (filetype >= EXT4_FT_MAX))
22 + (fl_index >= EXT4_FT_MAX))
25 - return (ext4_filetype_table[filetype]);
26 + if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_DIRDATA))
27 + return (ext4_filetype_table[fl_index]);
29 + return (ext4_filetype_table[fl_index]) |
30 + (filetype & EXT4_DIRENT_LUFID);
35 @@ -70,11 +77,11 @@ int ext4_check_dir_entry(const char *fun
36 const int rlen = ext4_rec_len_from_disk(de->rec_len,
37 dir->i_sb->s_blocksize);
39 - if (rlen < EXT4_DIR_REC_LEN(1))
40 + if (rlen < __EXT4_DIR_REC_LEN(1))
41 error_msg = "rec_len is smaller than minimal";
42 else if (rlen % 4 != 0)
43 error_msg = "rec_len % 4 != 0";
44 - else if (rlen < EXT4_DIR_REC_LEN(de->name_len))
45 + else if (rlen < EXT4_DIR_REC_LEN(de))
46 error_msg = "rec_len is too small for name_len";
47 else if (((char *) de - bh->b_data) + rlen > dir->i_sb->s_blocksize)
48 error_msg = "directory entry across blocks";
49 @@ -179,7 +186,7 @@ revalidate:
50 * failure will be detected in the
51 * dirent test below. */
52 if (ext4_rec_len_from_disk(de->rec_len,
53 - sb->s_blocksize) < EXT4_DIR_REC_LEN(1))
54 + sb->s_blocksize) < __EXT4_DIR_REC_LEN(1))
56 i += ext4_rec_len_from_disk(de->rec_len,
58 @@ -342,12 +349,17 @@ int ext4_htree_store_dirent(struct file
59 struct fname *fname, *new_fn;
60 struct dir_private_info *info;
64 info = (struct dir_private_info *) dir_file->private_data;
65 p = &info->root.rb_node;
67 /* Create and allocate the fname structure */
68 - len = sizeof(struct fname) + dirent->name_len + 1;
69 + if (dirent->file_type & EXT4_DIRENT_LUFID)
70 + extra_data = ext4_get_dirent_data_len(dirent);
72 + len = sizeof(struct fname) + dirent->name_len + extra_data;
74 new_fn = kzalloc(len, GFP_KERNEL);
77 @@ -356,7 +368,7 @@ int ext4_htree_store_dirent(struct file
78 new_fn->inode = le32_to_cpu(dirent->inode);
79 new_fn->name_len = dirent->name_len;
80 new_fn->file_type = dirent->file_type;
81 - memcpy(new_fn->name, dirent->name, dirent->name_len);
82 + memcpy(new_fn->name, dirent->name, dirent->name_len + extra_data);
83 new_fn->name[dirent->name_len] = 0;
86 Index: linux-stage/fs/ext4/ext4.h
87 ===================================================================
88 --- linux-stage.orig/fs/ext4/ext4.h
89 +++ linux-stage/fs/ext4/ext4.h
90 @@ -1172,6 +1172,7 @@ static inline void ext4_clear_inode_stat
91 #define EXT4_FEATURE_INCOMPAT_64BIT 0x0080
92 #define EXT4_FEATURE_INCOMPAT_MMP 0x0100
93 #define EXT4_FEATURE_INCOMPAT_FLEX_BG 0x0200
94 +#define EXT4_FEATURE_INCOMPAT_DIRDATA 0x1000
96 #define EXT4_FEATURE_COMPAT_SUPP EXT2_FEATURE_COMPAT_EXT_ATTR
97 #define EXT4_FEATURE_INCOMPAT_SUPP (EXT4_FEATURE_INCOMPAT_FILETYPE| \
98 @@ -1180,7 +1181,9 @@ static inline void ext4_clear_inode_stat
99 EXT4_FEATURE_INCOMPAT_EXTENTS| \
100 EXT4_FEATURE_INCOMPAT_64BIT| \
101 EXT4_FEATURE_INCOMPAT_FLEX_BG| \
102 - EXT4_FEATURE_INCOMPAT_MMP)
103 + EXT4_FEATURE_INCOMPAT_MMP| \
104 + EXT4_FEATURE_INCOMPAT_DIRDATA)
106 #define EXT4_FEATURE_RO_COMPAT_SUPP (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
107 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
108 EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
109 @@ -1262,6 +1265,43 @@ struct ext4_dir_entry_2 {
110 #define EXT4_FT_SYMLINK 7
112 #define EXT4_FT_MAX 8
113 +#define EXT4_FT_MASK 0xf
115 +#if EXT4_FT_MAX > EXT4_FT_MASK
116 +#error "conflicting EXT4_FT_MAX and EXT4_FT_MASK"
120 + * d_type has 4 unused bits, so it can hold four types data. these different
121 + * type of data (e.g. lustre data, high 32 bits of 64-bit inode number) can be
122 + * stored, in flag order, after file-name in ext4 dirent.
125 + * this flag is added to d_type if ext4 dirent has extra data after
126 + * filename. this data length is variable and length is stored in first byte
127 + * of data. data start after filename NUL byte.
128 + * This is used by Lustre FS.
130 +#define EXT4_DIRENT_LUFID 0x10
132 +#define EXT4_LUFID_MAGIC 0xAD200907UL
133 +struct ext4_dentry_param {
134 + __u32 edp_magic; /* EXT4_LUFID_MAGIC */
135 + char edp_len; /* size of edp_data in bytes */
136 + char edp_data[0]; /* packed array of data */
137 +} __attribute__((packed));
139 +static inline unsigned char *ext4_dentry_get_data(struct super_block *sb,
140 + struct ext4_dentry_param* p)
143 + if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_DIRDATA))
145 + if (p && p->edp_magic == EXT4_LUFID_MAGIC)
146 + return &p->edp_len;
152 * EXT4_DIR_PAD defines the directory entries boundaries
153 @@ -1270,8 +1310,11 @@ struct ext4_dir_entry_2 {
155 #define EXT4_DIR_PAD 4
156 #define EXT4_DIR_ROUND (EXT4_DIR_PAD - 1)
157 -#define EXT4_DIR_REC_LEN(name_len) (((name_len) + 8 + EXT4_DIR_ROUND) & \
158 +#define __EXT4_DIR_REC_LEN(name_len) (((name_len) + 8 + EXT4_DIR_ROUND) & \
160 +#define EXT4_DIR_REC_LEN(de) (__EXT4_DIR_REC_LEN(de->name_len +\
161 + ext4_get_dirent_data_len(de)))
163 #define EXT4_MAX_REC_LEN ((1<<16)-1)
165 static inline unsigned int
166 @@ -1611,7 +1654,7 @@ extern struct buffer_head * ext4_find_en
167 struct ext4_dir_entry_2 ** res_dir);
168 #define ll_ext4_find_entry(inode, dentry, res_dir) ext4_find_entry(dir, &(dentry)->d_name, res_dir)
169 extern int ext4_add_dot_dotdot(handle_t *handle, struct inode *dir,
170 - struct inode *inode);
171 + struct inode *inode, const void *, const void *);
172 extern int ext4_orphan_add(handle_t *, struct inode *);
173 extern int ext4_orphan_del(handle_t *, struct inode *);
174 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
175 @@ -1809,6 +1852,28 @@ static inline void ext4_update_i_disksiz
176 up_write(&EXT4_I(inode)->i_data_sem);
180 + * Compute the total directory entry data length.
181 + * This includes the filename and an implicit NUL terminator (always present),
182 + * and optional extensions. Each extension has a bit set in the high 4 bits of
183 + * de->file_type, and the extension length is the first byte in each entry.
186 +static inline int ext4_get_dirent_data_len(struct ext4_dir_entry_2 *de)
188 + char *len = de->name + de->name_len + 1 /* NUL terminator */;
190 + __u8 extra_data_flags = (de->file_type & ~EXT4_FT_MASK) >> 4;
192 + while (extra_data_flags) {
193 + if (extra_data_flags & 1) {
194 + dlen += *len + (dlen == 0);
197 + extra_data_flags >>= 1;
202 struct ext4_group_info {
203 unsigned long bb_state;
204 Index: linux-stage/fs/ext4/namei.c
205 ===================================================================
206 --- linux-stage.orig/fs/ext4/namei.c
207 +++ linux-stage/fs/ext4/namei.c
208 @@ -173,7 +173,8 @@ static unsigned dx_get_count(struct dx_e
209 static unsigned dx_get_limit(struct dx_entry *entries);
210 static void dx_set_count(struct dx_entry *entries, unsigned value);
211 static void dx_set_limit(struct dx_entry *entries, unsigned value);
212 -static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
213 +static inline unsigned dx_root_limit(__u32 blocksize,
214 + struct ext4_dir_entry_2 *dot_de, unsigned infosize);
215 static unsigned dx_node_limit(struct inode *dir);
216 static struct dx_frame *dx_probe(const struct qstr *d_name,
218 @@ -216,11 +217,12 @@ ext4_next_entry(struct ext4_dir_entry_2
220 struct dx_root_info * dx_get_dx_info(struct ext4_dir_entry_2 *de)
222 - /* get dotdot first */
223 - de = (struct ext4_dir_entry_2 *)((char *)de + EXT4_DIR_REC_LEN(1));
224 + BUG_ON(de->name_len != 1);
225 + /* get dotdot first */
226 + de = (struct ext4_dir_entry_2 *)((char *)de + EXT4_DIR_REC_LEN(de));
228 - /* dx root info is after dotdot entry */
229 - de = (struct ext4_dir_entry_2 *)((char *)de + EXT4_DIR_REC_LEN(2));
230 + /* dx root info is after dotdot entry */
231 + de = (struct ext4_dir_entry_2 *)((char *)de + EXT4_DIR_REC_LEN(de));
233 return (struct dx_root_info *) de;
235 @@ -265,16 +267,23 @@ static inline void dx_set_limit(struct d
236 ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
239 -static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
240 +static inline unsigned dx_root_limit(__u32 blocksize,
241 + struct ext4_dir_entry_2 *dot_de, unsigned infosize)
243 - unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
244 - EXT4_DIR_REC_LEN(2) - infosize;
245 + struct ext4_dir_entry_2 *dotdot_de;
246 + unsigned entry_space;
248 + BUG_ON(dot_de->name_len != 1);
249 + dotdot_de = ext4_next_entry(dot_de, blocksize);
250 + entry_space = blocksize - EXT4_DIR_REC_LEN(dot_de) -
251 + EXT4_DIR_REC_LEN(dotdot_de) - infosize;
253 return entry_space / sizeof(struct dx_entry);
256 static inline unsigned dx_node_limit(struct inode *dir)
258 - unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
259 + unsigned entry_space = dir->i_sb->s_blocksize - __EXT4_DIR_REC_LEN(0);
260 return entry_space / sizeof(struct dx_entry);
263 @@ -321,7 +330,7 @@ static struct stats dx_show_leaf(struct
264 printk(":%x.%u ", h.hash,
265 ((char *) de - base));
267 - space += EXT4_DIR_REC_LEN(de->name_len);
268 + space += EXT4_DIR_REC_LEN(de);
271 de = ext4_next_entry(de, size);
272 @@ -424,7 +433,8 @@ dx_probe(const struct qstr *d_name, stru
274 entries = (struct dx_entry *) (((char *)info) + info->info_length);
276 - if (dx_get_limit(entries) != dx_root_limit(dir,
277 + if (dx_get_limit(entries) != dx_root_limit(dir->i_sb->s_blocksize,
278 + (struct ext4_dir_entry_2*)bh->b_data,
279 info->info_length)) {
280 ext4_warning(dir->i_sb, "dx entry: limit != root limit");
282 @@ -480,14 +490,17 @@ dx_probe(const struct qstr *d_name, stru
283 if (!indirect--) return frame;
284 if (!(bh = ext4_bread (NULL,dir, dx_get_block(at), 0, err)))
286 - at = entries = ((struct dx_node *) bh->b_data)->entries;
287 + entries = ((struct dx_node *) bh->b_data)->entries;
288 if (dx_get_limit(entries) != dx_node_limit (dir)) {
289 ext4_warning(dir->i_sb,
290 - "dx entry: limit != node limit");
291 + "block %u(%lu): limit %u != node limit %u",
292 + dx_get_block(at), (long)bh->b_blocknr,
293 + dx_get_limit(entries), dx_node_limit(dir));
295 *err = ERR_BAD_DX_DIR;
302 @@ -613,7 +626,7 @@ static int htree_dirblock_to_tree(struct
303 de = (struct ext4_dir_entry_2 *) bh->b_data;
304 top = (struct ext4_dir_entry_2 *) ((char *) de +
305 dir->i_sb->s_blocksize -
306 - EXT4_DIR_REC_LEN(0));
307 + __EXT4_DIR_REC_LEN(0));
308 for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
309 if (!ext4_check_dir_entry("htree_dirblock_to_tree", dir, de, bh,
310 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
311 @@ -1025,7 +1038,7 @@ static struct buffer_head * ext4_dx_find
313 de = (struct ext4_dir_entry_2 *) bh->b_data;
314 top = (struct ext4_dir_entry_2 *) ((char *) de + sb->s_blocksize -
315 - EXT4_DIR_REC_LEN(0));
316 + __EXT4_DIR_REC_LEN(0));
317 for (; de < top; de = ext4_next_entry(de, sb->s_blocksize)) {
318 int off = (block << EXT4_BLOCK_SIZE_BITS(sb))
319 + ((char *) de - bh->b_data);
320 @@ -1186,7 +1199,7 @@ dx_move_dirents(char *from, char *to, st
322 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
323 (from + (map->offs<<2));
324 - rec_len = EXT4_DIR_REC_LEN(de->name_len);
325 + rec_len = EXT4_DIR_REC_LEN(de);
326 memcpy (to, de, rec_len);
327 ((struct ext4_dir_entry_2 *) to)->rec_len =
328 ext4_rec_len_to_disk(rec_len, blocksize);
329 @@ -1210,7 +1223,7 @@ static struct ext4_dir_entry_2* dx_pack_
330 while ((char*)de < base + blocksize) {
331 next = ext4_next_entry(de, blocksize);
332 if (de->inode && de->name_len) {
333 - rec_len = EXT4_DIR_REC_LEN(de->name_len);
334 + rec_len = EXT4_DIR_REC_LEN(de);
336 memmove(to, de, rec_len);
337 to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
338 @@ -1340,10 +1353,16 @@ static int add_dirent_to_buf(handle_t *h
339 unsigned int offset = 0;
340 unsigned int blocksize = dir->i_sb->s_blocksize;
341 unsigned short reclen;
342 - int nlen, rlen, err;
343 + int nlen, rlen, err, dlen = 0;
344 + unsigned char *data;
347 - reclen = EXT4_DIR_REC_LEN(namelen);
348 + data = ext4_dentry_get_data(inode->i_sb, (struct ext4_dentry_param *)
351 + dlen = (*data) + 1;
353 + reclen = __EXT4_DIR_REC_LEN(namelen + dlen);
355 de = (struct ext4_dir_entry_2 *)bh->b_data;
356 top = bh->b_data + blocksize - reclen;
357 @@ -1353,7 +1372,7 @@ static int add_dirent_to_buf(handle_t *h
359 if (ext4_match(namelen, name, de))
361 - nlen = EXT4_DIR_REC_LEN(de->name_len);
362 + nlen = EXT4_DIR_REC_LEN(de);
363 rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
364 if ((de->inode? rlen - nlen: rlen) >= reclen)
366 @@ -1371,7 +1390,7 @@ static int add_dirent_to_buf(handle_t *h
369 /* By now the buffer is marked for journaling */
370 - nlen = EXT4_DIR_REC_LEN(de->name_len);
371 + nlen = EXT4_DIR_REC_LEN(de);
372 rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
374 struct ext4_dir_entry_2 *de1 = (struct ext4_dir_entry_2 *)((char *)de + nlen);
375 @@ -1387,6 +1406,12 @@ static int add_dirent_to_buf(handle_t *h
377 de->name_len = namelen;
378 memcpy(de->name, name, namelen);
380 + de->name[namelen] = 0;
381 + memcpy(&de->name[namelen + 1], data, *(char *) data);
382 + de->file_type |= EXT4_DIRENT_LUFID;
386 * XXX shouldn't update any times until successful
387 * completion of syscall, but too many callers depend
388 @@ -1485,7 +1510,8 @@ static int make_indexed_dir(handle_t *ha
390 dx_set_block(entries, 1);
391 dx_set_count(entries, 1);
392 - dx_set_limit(entries, dx_root_limit(dir, sizeof(*dx_info)));
393 + dx_set_limit(entries, dx_root_limit(dir->i_sb->s_blocksize,
394 + dot_de, sizeof(*dx_info)));
396 /* Initialize as for dx_probe */
397 hinfo.hash_version = dx_info->hash_version;
398 @@ -1516,6 +1542,8 @@ static int ext4_update_dotdot(handle_t *
399 struct buffer_head * dir_block;
400 struct ext4_dir_entry_2 * de;
401 int len, journal = 0, err = 0;
406 return PTR_ERR(handle);
407 @@ -1531,19 +1559,24 @@ static int ext4_update_dotdot(handle_t *
408 /* the first item must be "." */
409 assert(de->name_len == 1 && de->name[0] == '.');
410 len = le16_to_cpu(de->rec_len);
411 - assert(len >= EXT4_DIR_REC_LEN(1));
412 - if (len > EXT4_DIR_REC_LEN(1)) {
413 + assert(len >= __EXT4_DIR_REC_LEN(1));
414 + if (len > __EXT4_DIR_REC_LEN(1)) {
415 BUFFER_TRACE(dir_block, "get_write_access");
416 err = ext4_journal_get_write_access(handle, dir_block);
421 - de->rec_len = cpu_to_le16(EXT4_DIR_REC_LEN(1));
422 + de->rec_len = cpu_to_le16(EXT4_DIR_REC_LEN(de));
425 - len -= EXT4_DIR_REC_LEN(1);
426 - assert(len == 0 || len >= EXT4_DIR_REC_LEN(2));
427 + len -= EXT4_DIR_REC_LEN(de);
428 + data = ext4_dentry_get_data(dir->i_sb,
429 + (struct ext4_dentry_param *) dentry->d_fsdata);
432 + assert(len == 0 || len >= __EXT4_DIR_REC_LEN(2 + dlen));
434 de = (struct ext4_dir_entry_2 *)
435 ((char *) de + le16_to_cpu(de->rec_len));
437 @@ -1557,10 +1590,15 @@ static int ext4_update_dotdot(handle_t *
439 de->rec_len = cpu_to_le16(len);
441 - assert(le16_to_cpu(de->rec_len) >= EXT4_DIR_REC_LEN(2));
442 + assert(le16_to_cpu(de->rec_len) >= __EXT4_DIR_REC_LEN(2));
444 strcpy (de->name, "..");
445 ext4_set_de_type(dir->i_sb, de, S_IFDIR);
448 + memcpy(&de->name[2 + 1], data, dlen);
449 + de->file_type |= EXT4_DIRENT_LUFID;
454 @@ -1982,12 +2020,13 @@ retry:
455 /* Initialize @inode as a subdirectory of @dir, and add the
456 * "." and ".." entries into the first directory block. */
457 int ext4_add_dot_dotdot(handle_t *handle, struct inode * dir,
458 - struct inode *inode)
459 + struct inode *inode,
460 + const void *data1, const void *data2)
462 unsigned int blocksize = dir->i_sb->s_blocksize;
463 struct buffer_head * dir_block;
464 struct ext4_dir_entry_2 * de;
466 + int err = 0, dot_reclen;
469 return PTR_ERR(handle);
470 @@ -1999,28 +2038,42 @@ int ext4_add_dot_dotdot(handle_t *handle
471 inode->i_fop = &ext4_dir_operations;
472 inode->i_size = EXT4_I(inode)->i_disksize = inode->i_sb->s_blocksize;
473 dir_block = ext4_bread(handle, inode, 0, 1, &err);
475 - clear_nlink(inode);
476 - ext4_mark_inode_dirty(handle, inode);
482 BUFFER_TRACE(dir_block, "get_write_access");
483 ext4_journal_get_write_access(handle, dir_block);
484 de = (struct ext4_dir_entry_2 *) dir_block->b_data;
485 de->inode = cpu_to_le32(inode->i_ino);
487 - de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
489 strcpy(de->name, ".");
490 ext4_set_de_type(dir->i_sb, de, S_IFDIR);
491 + /* get packed fid data*/
492 + data1 = ext4_dentry_get_data(dir->i_sb,
493 + (struct ext4_dentry_param *) data1);
496 + memcpy(&de->name[2], data1, *(char *) data1);
497 + de->file_type |= EXT4_DIRENT_LUFID;
499 + de->rec_len = cpu_to_le16(EXT4_DIR_REC_LEN(de));
500 + dot_reclen = cpu_to_le16(de->rec_len);
502 de = ext4_next_entry(de, blocksize);
503 de->inode = cpu_to_le32(dir->i_ino);
504 - de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(1),
505 + de->rec_len = ext4_rec_len_to_disk(blocksize - dot_reclen,
508 strcpy(de->name, "..");
509 ext4_set_de_type(dir->i_sb, de, S_IFDIR);
510 + data2 = ext4_dentry_get_data(dir->i_sb,
511 + (struct ext4_dentry_param *) data2);
514 + memcpy(&de->name[3], data2, *(char *) data2);
515 + de->file_type |= EXT4_DIRENT_LUFID;
519 BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
520 ext4_handle_dirty_metadata(handle, dir, dir_block);
521 @@ -2057,9 +2110,14 @@ retry:
525 - err = ext4_add_dot_dotdot(handle, dir, inode);
527 + err = ext4_add_dot_dotdot(handle, dir, inode, NULL, NULL);
529 + clear_nlink(inode);
530 + unlock_new_inode(inode);
531 + ext4_mark_inode_dirty(handle, inode);
536 err = ext4_add_entry(handle, dentry, inode);
538 @@ -2093,7 +2151,7 @@ static int empty_dir(struct inode *inode
542 - if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2) ||
543 + if (inode->i_size < __EXT4_DIR_REC_LEN(1) + __EXT4_DIR_REC_LEN(2) ||
544 !(bh = ext4_bread(NULL, inode, 0, 0, &err))) {
546 ext4_error(inode->i_sb,