Lines Matching +full:fixed +full:- +full:links
1 .. SPDX-License-Identifier: GPL-2.0
4 -----------
15 links and is in general more seek-happy than ext4 due to its simpler
22 ``(inode_number - 1) / sb.s_inodes_per_group``, and the offset into the
23 group's table is ``(inode_number - 1) % sb.s_inodes_per_group``. There
31 .. list-table::
33 :header-rows: 1
35 * - Offset
36 - Size
37 - Name
38 - Description
39 * - 0x0
40 - \_\_le16
41 - i\_mode
42 - File mode. See the table i_mode_ below.
43 * - 0x2
44 - \_\_le16
45 - i\_uid
46 - Lower 16-bits of Owner UID.
47 * - 0x4
48 - \_\_le32
49 - i\_size\_lo
50 - Lower 32-bits of size in bytes.
51 * - 0x8
52 - \_\_le32
53 - i\_atime
54 - Last access time, in seconds since the epoch. However, if the EA\_INODE
57 * - 0xC
58 - \_\_le32
59 - i\_ctime
60 - Last inode change time, in seconds since the epoch. However, if the
64 * - 0x10
65 - \_\_le32
66 - i\_mtime
67 - Last data modification time, in seconds since the epoch. However, if the
71 * - 0x14
72 - \_\_le32
73 - i\_dtime
74 - Deletion Time, in seconds since the epoch.
75 * - 0x18
76 - \_\_le16
77 - i\_gid
78 - Lower 16-bits of GID.
79 * - 0x1A
80 - \_\_le16
81 - i\_links\_count
82 - Hard link count. Normally, ext4 does not permit an inode to have more
83 than 65,000 hard links. This applies to files as well as directories,
88 field to 1 to indicate that the number of hard links is not known.
89 * - 0x1C
90 - \_\_le32
91 - i\_blocks\_lo
92 - Lower 32-bits of “block” count. If the huge\_file feature flag is not
93 set on the filesystem, the file consumes ``i_blocks_lo`` 512-byte blocks
96 << 32)`` 512-byte blocks on disk. If huge\_file is set and
100 * - 0x20
101 - \_\_le32
102 - i\_flags
103 - Inode flags. See the table i_flags_ below.
104 * - 0x24
105 - 4 bytes
106 - i\_osd1
107 - See the table i_osd1_ for more details.
108 * - 0x28
109 - 60 bytes
110 - i\_block[EXT4\_N\_BLOCKS=15]
111 - Block map or extent tree. See the section “The Contents of inode.i\_block”.
112 * - 0x64
113 - \_\_le32
114 - i\_generation
115 - File version (for NFS).
116 * - 0x68
117 - \_\_le32
118 - i\_file\_acl\_lo
119 - Lower 32-bits of extended attribute block. ACLs are of course one of
122 * - 0x6C
123 - \_\_le32
124 - i\_size\_high / i\_dir\_acl
125 - Upper 32-bits of file/directory size. In ext2/3 this field was named
127 * - 0x70
128 - \_\_le32
129 - i\_obso\_faddr
130 - (Obsolete) fragment address.
131 * - 0x74
132 - 12 bytes
133 - i\_osd2
134 - See the table i_osd2_ for more details.
135 * - 0x80
136 - \_\_le16
137 - i\_extra\_isize
138 - Size of this inode - 128. Alternately, the size of the extended inode
140 * - 0x82
141 - \_\_le16
142 - i\_checksum\_hi
143 - Upper 16-bits of the inode checksum.
144 * - 0x84
145 - \_\_le32
146 - i\_ctime\_extra
147 - Extra change time bits. This provides sub-second precision. See Inode
149 * - 0x88
150 - \_\_le32
151 - i\_mtime\_extra
152 - Extra modification time bits. This provides sub-second precision.
153 * - 0x8C
154 - \_\_le32
155 - i\_atime\_extra
156 - Extra access time bits. This provides sub-second precision.
157 * - 0x90
158 - \_\_le32
159 - i\_crtime
160 - File creation time, in seconds since the epoch.
161 * - 0x94
162 - \_\_le32
163 - i\_crtime\_extra
164 - Extra file creation time bits. This provides sub-second precision.
165 * - 0x98
166 - \_\_le32
167 - i\_version\_hi
168 - Upper 32-bits for version number.
169 * - 0x9C
170 - \_\_le32
171 - i\_projid
172 - Project ID.
178 .. list-table::
180 :header-rows: 1
182 * - Value
183 - Description
184 * - 0x1
185 - S\_IXOTH (Others may execute)
186 * - 0x2
187 - S\_IWOTH (Others may write)
188 * - 0x4
189 - S\_IROTH (Others may read)
190 * - 0x8
191 - S\_IXGRP (Group members may execute)
192 * - 0x10
193 - S\_IWGRP (Group members may write)
194 * - 0x20
195 - S\_IRGRP (Group members may read)
196 * - 0x40
197 - S\_IXUSR (Owner may execute)
198 * - 0x80
199 - S\_IWUSR (Owner may write)
200 * - 0x100
201 - S\_IRUSR (Owner may read)
202 * - 0x200
203 - S\_ISVTX (Sticky bit)
204 * - 0x400
205 - S\_ISGID (Set GID)
206 * - 0x800
207 - S\_ISUID (Set UID)
208 * -
209 - These are mutually-exclusive file types:
210 * - 0x1000
211 - S\_IFIFO (FIFO)
212 * - 0x2000
213 - S\_IFCHR (Character device)
214 * - 0x4000
215 - S\_IFDIR (Directory)
216 * - 0x6000
217 - S\_IFBLK (Block device)
218 * - 0x8000
219 - S\_IFREG (Regular file)
220 * - 0xA000
221 - S\_IFLNK (Symbolic link)
222 * - 0xC000
223 - S\_IFSOCK (Socket)
229 .. list-table::
231 :header-rows: 1
233 * - Value
234 - Description
235 * - 0x1
236 - This file requires secure deletion (EXT4\_SECRM\_FL). (not implemented)
237 * - 0x2
238 - This file should be preserved, should undeletion be desired
240 * - 0x4
241 - File is compressed (EXT4\_COMPR\_FL). (not really implemented)
242 * - 0x8
243 - All writes to the file must be synchronous (EXT4\_SYNC\_FL).
244 * - 0x10
245 - File is immutable (EXT4\_IMMUTABLE\_FL).
246 * - 0x20
247 - File can only be appended (EXT4\_APPEND\_FL).
248 * - 0x40
249 - The dump(1) utility should not dump this file (EXT4\_NODUMP\_FL).
250 * - 0x80
251 - Do not update access time (EXT4\_NOATIME\_FL).
252 * - 0x100
253 - Dirty compressed file (EXT4\_DIRTY\_FL). (not used)
254 * - 0x200
255 - File has one or more compressed clusters (EXT4\_COMPRBLK\_FL). (not used)
256 * - 0x400
257 - Do not compress file (EXT4\_NOCOMPR\_FL). (not used)
258 * - 0x800
259 - Encrypted inode (EXT4\_ENCRYPT\_FL). This bit value previously was
261 * - 0x1000
262 - Directory has hashed indexes (EXT4\_INDEX\_FL).
263 * - 0x2000
264 - AFS magic directory (EXT4\_IMAGIC\_FL).
265 * - 0x4000
266 - File data must always be written through the journal
268 * - 0x8000
269 - File tail should not be merged (EXT4\_NOTAIL\_FL). (not used by ext4)
270 * - 0x10000
271 - All directory entry data should be written synchronously (see
273 * - 0x20000
274 - Top of directory hierarchy (EXT4\_TOPDIR\_FL).
275 * - 0x40000
276 - This is a huge file (EXT4\_HUGE\_FILE\_FL).
277 * - 0x80000
278 - Inode uses extents (EXT4\_EXTENTS\_FL).
279 * - 0x200000
280 - Inode stores a large extended attribute value in its data blocks
282 * - 0x400000
283 - This file has blocks allocated past EOF (EXT4\_EOFBLOCKS\_FL).
285 * - 0x01000000
286 - Inode is a snapshot (``EXT4_SNAPFILE_FL``). (not in mainline)
287 * - 0x04000000
288 - Snapshot is being deleted (``EXT4_SNAPFILE_DELETED_FL``). (not in
290 * - 0x08000000
291 - Snapshot shrink has completed (``EXT4_SNAPFILE_SHRUNK_FL``). (not in
293 * - 0x10000000
294 - Inode has inline data (EXT4\_INLINE\_DATA\_FL).
295 * - 0x20000000
296 - Create children with the same project ID (EXT4\_PROJINHERIT\_FL).
297 * - 0x80000000
298 - Reserved for ext4 library (EXT4\_RESERVED\_FL).
299 * -
300 - Aggregate flags:
301 * - 0x4BDFFF
302 - User-visible flags.
303 * - 0x4B80FF
304 - User-modifiable flags. Note that while EXT4\_JOURNAL\_DATA\_FL and
316 .. list-table::
318 :header-rows: 1
320 * - Offset
321 - Size
322 - Name
323 - Description
324 * - 0x0
325 - \_\_le32
326 - l\_i\_version
327 - Inode version. However, if the EA\_INODE inode flag is set, this inode
333 .. list-table::
335 :header-rows: 1
337 * - Offset
338 - Size
339 - Name
340 - Description
341 * - 0x0
342 - \_\_le32
343 - h\_i\_translator
344 - ??
348 .. list-table::
350 :header-rows: 1
352 * - Offset
353 - Size
354 - Name
355 - Description
356 * - 0x0
357 - \_\_le32
358 - m\_i\_reserved
359 - ??
367 .. list-table::
369 :header-rows: 1
371 * - Offset
372 - Size
373 - Name
374 - Description
375 * - 0x0
376 - \_\_le16
377 - l\_i\_blocks\_high
378 - Upper 16-bits of the block count. Please see the note attached to
380 * - 0x2
381 - \_\_le16
382 - l\_i\_file\_acl\_high
383 - Upper 16-bits of the extended attribute block (historically, the file
385 * - 0x4
386 - \_\_le16
387 - l\_i\_uid\_high
388 - Upper 16-bits of the Owner UID.
389 * - 0x6
390 - \_\_le16
391 - l\_i\_gid\_high
392 - Upper 16-bits of the GID.
393 * - 0x8
394 - \_\_le16
395 - l\_i\_checksum\_lo
396 - Lower 16-bits of the inode checksum.
397 * - 0xA
398 - \_\_le16
399 - l\_i\_reserved
400 - Unused.
404 .. list-table::
406 :header-rows: 1
408 * - Offset
409 - Size
410 - Name
411 - Description
412 * - 0x0
413 - \_\_le16
414 - h\_i\_reserved1
415 - ??
416 * - 0x2
417 - \_\_u16
418 - h\_i\_mode\_high
419 - Upper 16-bits of the file mode.
420 * - 0x4
421 - \_\_le16
422 - h\_i\_uid\_high
423 - Upper 16-bits of the Owner UID.
424 * - 0x6
425 - \_\_le16
426 - h\_i\_gid\_high
427 - Upper 16-bits of the GID.
428 * - 0x8
429 - \_\_u32
430 - h\_i\_author
431 - Author code?
435 .. list-table::
437 :header-rows: 1
439 * - Offset
440 - Size
441 - Name
442 - Description
443 * - 0x0
444 - \_\_le16
445 - h\_i\_reserved1
446 - ??
447 * - 0x2
448 - \_\_u16
449 - m\_i\_file\_acl\_high
450 - Upper 16-bits of the extended attribute block (historically, the file
452 * - 0x4
453 - \_\_u32
454 - m\_i\_reserved2[2]
455 - ??
460 In ext2 and ext3, the inode structure size was fixed at 128 bytes
463 on-disk inode at format time for all inodes in the filesystem to provide
464 space beyond the end of the original ext2 inode. The on-disk inode
467 128-byte ext2 inode is recorded in the ``i_extra_isize`` field for each
469 having to upgrade all of the on-disk inodes. Access to fields beyond
481 Each block group contains ``sb->s_inodes_per_group`` inodes. Because
484 ``bg = (inode_num - 1) / sb->s_inodes_per_group``. The particular inode
486 ``index = (inode_num - 1) % sb->s_inodes_per_group``. To get the byte
488 ``offset = index * sb->s_inode_size``.
494 structure -- inode change time (ctime), access time (atime), data
496 are 32-bit signed integers that represent seconds since the Unix epoch
497 (1970-01-01 00:00:00 GMT), which means that the fields will overflow in
504 If the inode structure size ``sb->s_inode_size`` is larger than 128
507 inode fields are widened to 64 bits. Within this “extra” 32-bit field,
508 the lower two bits are used to extend the 32-bit seconds field to be 34
512 creation time (crtime); this field is 64-bits wide and decoded in the
513 same manner as 64-bit [cma]time. Neither crtime nor dtime are accessible
516 We use the 32-bit signed time value plus (2^32 \* (extra epoch bits)).
519 .. list-table::
521 :header-rows: 1
523 * - Extra epoch bits
524 - MSB of 32-bit time
525 - Adjustment for signed 32-bit to 64-bit tv\_sec
526 - Decoded 64-bit tv\_sec
527 - valid time range
528 * - 0 0
529 - 1
530 - 0
531 - ``-0x80000000 - -0x00000001``
532 - 1901-12-13 to 1969-12-31
533 * - 0 0
534 - 0
535 - 0
536 - ``0x000000000 - 0x07fffffff``
537 - 1970-01-01 to 2038-01-19
538 * - 0 1
539 - 1
540 - 0x100000000
541 - ``0x080000000 - 0x0ffffffff``
542 - 2038-01-19 to 2106-02-07
543 * - 0 1
544 - 0
545 - 0x100000000
546 - ``0x100000000 - 0x17fffffff``
547 - 2106-02-07 to 2174-02-25
548 * - 1 0
549 - 1
550 - 0x200000000
551 - ``0x180000000 - 0x1ffffffff``
552 - 2174-02-25 to 2242-03-16
553 * - 1 0
554 - 0
555 - 0x200000000
556 - ``0x200000000 - 0x27fffffff``
557 - 2242-03-16 to 2310-04-04
558 * - 1 1
559 - 1
560 - 0x300000000
561 - ``0x280000000 - 0x2ffffffff``
562 - 2310-04-04 to 2378-04-22
563 * - 1 1
564 - 0
565 - 0x300000000
566 - ``0x300000000 - 0x37fffffff``
567 - 2378-04-22 to 2446-05-10
571 long-standing bugs decoding and encoding dates beyond 2038, which don't
572 seem to be fixed as of kernel 3.12 and e2fsprogs 1.42.8. 64-bit kernels
574 1970. At some point the kernel will be fixed and e2fsck will fix this