1xfs_io(8) System Manager's Manual xfs_io(8)
2
6 xfs_io - debug the I/O path of an XFS filesystem
7
9 xfs_io [ -adfimrRstxT ] [ -c cmd ] ... [ -C cmd ] ... [ -p prog ] [
10 file ]
11 xfs_io -V
12
14 xfs_io is a debugging tool like xfs_db(8), but is aimed at examining
15 the regular file I/O paths rather than the raw XFS volume itself.
16 These code paths include not only the obvious read/write/mmap inter‐
17 faces for manipulating files, but also cover all of the XFS extensions
18 (such as space preallocation, additional inode flags, etc).
19
21 xfs_io commands may be run interactively (the default) or as arguments
22 on the command line. Interactive mode always runs commands on the cur‐
23 rent open file, whilst commands run from the command line may be
24 repeated on all open files rather than just the current open file. In
25 general, open file iteration will occur for commands that operate on
26 file content or state. In contrast, commands that operate on filesystem
27 or system-wide state will only be run on the current file regardless of
28 how many files are currently open. Multiple arguments may be given on
29 the command line and they are run in the sequence given. The program
30 exits one all commands have been run.
31 -c cmd Run the specified command on all currently open files. To
33 maintain compatibility with historical usage, commands that
34 can not be run on all open files will still be run but only
35 execute once on the current open file. Multiple -c arguments
36 may be given and may be interleaved on the command line in
37 any order with -C commands.
38 -C cmd Run the specified command only on the current open file.
40 Multiple -C arguments may be given and may be interleaved on
41 the command line in any order with -c commands.
42 -p prog Set the program name for prompts and some error messages, the
44 default value is xfs_io.
45 -f Create file if it does not already exist.
47 -r Open file read-only, initially. This is required if file is
49 immutable or append-only.
50 -i Start an idle thread. The purpose of this idle thread is to
52 test io from a multi threaded process. With single threaded
53 process, the file table is not shared and file structs are
54 not reference counted. Spawning an idle thread can help
55 detecting file struct reference leaks.
56 -x Expert mode. Dangerous commands are only available in this
58 mode. These commands also tend to require additional privi‐
59 leges.
60 -V Prints the version number and exits.
62 The other open(2) options described below are also available from the
64 command line.
65
67 xfs_io maintains a number of open files and memory mappings. Files can
68 be initially opened on the command line (optionally), and additional
69 files can also be opened later.
70 xfs_io commands can be broken up into three groups. Some commands are
72 aimed at doing regular file I/O - read, write, sync, space prealloca‐
73 tion, etc.
74 The second set of commands exist for manipulating memory mapped regions
76 of a file - mapping, accessing, storing, unmapping, flushing, etc.
77 The remaining commands are for the navigation and display of data
79 structures relating to the open files, mappings, and the filesystems
80 where they reside.
81 Many commands have extensive online help. Use the help command for more
83 details on any command.
84
86 file [ N ]
87 Display a list of all open files and (optionally) switch to an
88 alternate current open file.
89 open [[ -acdfrstRTPL ] path ]
91 Closes the current file, and opens the file specified by path
92 instead. Without any arguments, displays statistics about the
93 current file - see the stat command.
94 -a opens append-only (O_APPEND).
95 -d opens for direct I/O (O_DIRECT).
96 -f creates the file if it doesn't already exist (O_CREAT).
97 -r opens read-only (O_RDONLY).
98 -s opens for synchronous I/O (O_SYNC).
99 -t truncates on open (O_TRUNC).
100 -n opens in non-blocking mode if possible (O_NONBLOCK).
101 -T create a temporary file not linked into the filesystem
102 namespace (O_TMPFILE). The pathname passed must refer to
103 a directory which is treated as virtual parent for the
104 newly created invisible file. Can not be used together
105 with the -r option.
106 -R marks the file as a realtime XFS file after opening it,
107 if it is not already marked as such.
108 -P opens the path as a referent only (O_PATH). This is
109 incompatible with other flags specifying other O_xxx
110 flags apart from -L.
111 -L doesn't follow symlinks (O_NOFOLLOW). This is incompati‐
112 ble with other flags specifying other O_xxx flags apart
113 from -P.
114 o See the open command.
116 close Closes the current open file, marking the next open file as cur‐
118 rent (if one exists).
119 c See the close command.
121 pread [ -b bsize ] [ -v ] [ -FBR [ -Z seed ] ] [ -V vectors ] offset
123 length
124 Reads a range of bytes in a specified blocksize from the given
125 offset.
126 -b can be used to set the blocksize into which the read(2)
127 requests will be split. The default blocksize is 4096
128 bytes.
129 -v dump the contents of the buffer after reading, by default
130 only the count of bytes actually read is dumped.
131 -F read the buffers in a forwards sequential direction.
132 -B read the buffers in a reserve sequential direction.
133 -R read the buffers in the give range in a random order.
134 -Z seed
135 specify the random number seed used for random reads.
136 -V vectors
137 Use the vectored IO read syscall preadv(2) with a number
138 of blocksize length iovecs. The number of iovecs is set
139 by the vectors parameter.
140 r See the pread command.
142 pwrite [ -i file ] [ -dDwNOW ] [ -s skip ] [ -b size ] [ -S seed ] [
144 -FBR [ -Z zeed ] ] [ -V vectors ] offset length
145 Writes a range of bytes in a specified blocksize from the given
146 offset. The bytes written can be either a set pattern or read
147 in from another file before writing.
148 -i allows an input file to be specified as the source of the
149 data to be written.
150 -d causes direct I/O, rather than the usual buffered I/O, to
151 be used when reading the input file.
152 -w call fdatasync(2) once all writes are complete (included
153 in timing results)
154 -N Perform the pwritev2(2) call with RWF_NOWAIT.
155 -D Perform the pwritev2(2) call with RWF_DSYNC.
156 -O perform pwrite once and return the (maybe partial) bytes
157 written.
158 -W call fsync(2) once all writes are complete (included in
159 timing results)
160 -s specifies the number of bytes to skip from the start of
161 the input file before starting to read.
162 -b used to set the blocksize into which the write(2)
163 requests will be split. The default blocksize is 4096
164 bytes.
165 -S used to set the (repeated) fill pattern which is used
166 when the data to write is not coming from a file. The
167 default buffer fill pattern value is 0xcdcdcdcd.
168 -F write the buffers in a forwards sequential direction.
169 -B write the buffers in a reserve sequential direction.
170 -R write the buffers in the give range in a random order.
171 -Z seed
172 specify the random number seed used for random write
173 -V vectors
174 Use the vectored IO write syscall pwritev(2) with a num‐
175 ber of blocksize length iovecs. The number of iovecs is
176 set by the vectors parameter.
177 w See the pwrite command.
179 bmap [ -adelpv ] [ -n nx ]
181 Prints the block mapping for the current open file. Refer to the
182 xfs_bmap(8) manual page for complete documentation.
183 fiemap [ -alv ] [ -n nx ] [ offset [ len ]]
185 Prints the block mapping for the current open file using the
186 fiemap ioctl. Options behave as described in the xfs_bmap(8)
187 manual page.
188 Optionally, this command also supports passing the start offset
190 from where to begin the mapping and the length of that region.
191 The kernel will return any full extents which intersect with the
192 requested range, and the fiemap command will print them in their
193 entirety. If the requested range starts or ends in a hole,
194 fiemap will print the hole, truncated to the requested range.
195 fsmap [ -d | -l | -r ] [ -m | -v ] [ -n nx ] [ start ] [ end ]
197 Prints the mapping of disk blocks used by the filesystem hosting
198 the current file. The map lists each extent used by files,
199 allocation group metadata, journalling logs, and static filesys‐
200 tem metadata, as well as any regions that are unused. Each line
201 of the listings takes the following form:
202 extent: major:minor [startblock..endblock]: owner startoff‐
204 set..endoffset length
205 Static filesystem metadata, allocation group metadata, btrees,
207 journalling logs, and free space are marked by replacing the
208 startoffset..endoffset with the appropriate marker. All blocks,
209 offsets, and lengths are specified in units of 512-byte blocks,
210 no matter what the filesystem's block size is. The optional
211 start and end arguments can be used to constrain the output to a
212 particular range of disk blocks. If these two options are spec‐
213 ified, exactly one of -d, -l, or -r must also be set.
214 -d Display only extents from the data device. This
215 option only applies for XFS filesystems.
216 -l Display only extents from the external log device.
217 This option only applies to XFS filesystems.
218 -r Display only extents from the realtime device. This
219 option only applies to XFS filesystems.
220 -m Display results in a machine readable format (CSV).
221 This option is not compatible with the -v flag. The
222 columns of the output are: extent number, device
223 major, device minor, physical start, physical end,
224 owner, offset start, offset end, length. The start,
225 end, and length numbers are provided in units of 512b.
226 The owner field is a special string that takes the
227 form:
228 inode_%lld_data
230 for inode data.
231 inode_%lld_data_bmbt
232 for inode data extent maps.
233 inode_%lld_attr
234 for inode extended attribute data.
235 inode_%lld_attr_bmbt
236 for inode extended attribute extent maps.
237 special_%u:%u
238 for other filesystem metadata.
239 -n num_extents
242 If this option is given, fsmap obtains the extent list
243 of the file in groups of num_extents extents. In the
244 absence of -n, fsmap queries the system for extents in
245 groups of 131,072 records.
246 -v Shows verbose information. When this flag is speci‐
248 fied, additional AG specific information is appended
249 to each line in the following form:
250 agno (startagblock..endagblock) nblocks flags
252 A second -v option will print out the flags legend.
254 This option is not compatible with the -m flag.
255 extsize [ -R | -D ] [ value ]
257 Display and/or modify the preferred extent size used when allo‐
258 cating space for the currently open file. If the -R option is
259 specified, a recursive descent is performed for all directory
260 entries below the currently open file (-D can be used to
261 restrict the output to directories only). If the target file is
262 a directory, then the inherited extent size is set for that
263 directory (new files created in that directory inherit that
264 extent size). The value should be specified in bytes, or using
265 one of the usual units suffixes (k, m, g, b, etc). The extent
266 size is always reported in units of bytes.
267 cowextsize [ -R | -D ] [ value ]
269 Display and/or modify the preferred copy-on-write extent size
270 used when allocating space for the currently open file. If the
271 -R option is specified, a recursive descent is performed for all
272 directory entries below the currently open file (-D can be used
273 to restrict the output to directories only). If the target file
274 is a directory, then the inherited CoW extent size is set for
275 that directory (new files created in that directory inherit that
276 CoW extent size). The value should be specified in bytes, or
277 using one of the usual units suffixes (k, m, g, b, etc). The
278 extent size is always reported in units of bytes.
279 allocsp size 0
281 Sets the size of the file to size and zeroes any additional
282 space allocated using the XFS_IOC_ALLOCSP/XFS_IOC_FREESP system
283 call described in the xfsctl(3) manual page. allocsp and freesp
284 do exactly the same thing.
285 freesp size 0
287 See the allocsp command.
288 fadvise [ -r | -s | [[ -d | -n | -w ] offset length ]]
290 On platforms which support it, allows hints be given to the sys‐
291 tem regarding the expected I/O patterns on the file. The range
292 arguments are required by some advise commands ([*] below), and
293 the others must have no range arguments. With no arguments, the
294 POSIX_FADV_NORMAL advice is implied (default readahead).
295 -d the data will not be accessed again in the near future
296 (POSIX_FADV_DONTNEED[*]).
297 -n data will be accessed once and not be reused
298 (POSIX_FADV_NOREUSE[*]).
299 -r expect access to data in random order (POSIX_FADV_RAN‐
300 DOM), which sets readahead to zero.
301 -s expect access to data in sequential order
302 (POSIX_FADV_SEQUENTIAL), which doubles the default reada‐
303 head on the file.
304 -w advises the specified data will be needed again
305 (POSIX_FADV_WILLNEED[*]) which forces the maximum reada‐
306 head.
307 fdatasync
309 Calls fdatasync(2) to flush the file's in-core data to disk.
310 fsync Calls fsync(2) to flush all in-core file state to disk.
312 s See the fsync command.
314 sync_range [ -a | -b | -w ] offset length
316 On platforms which support it, allows control of syncing a range
317 of the file to disk. With no options, SYNC_FILE_RANGE_WRITE is
318 implied on the range supplied.
319 -a wait for IO in the given range to finish after writing
320 (SYNC_FILE_RANGE_WAIT_AFTER).
321 -b wait for IO in the given range to finish before writing
322 (SYNC_FILE_RANGE_WAIT_BEFORE).
323 -w start writeback of dirty data in the given range
324 (SYNC_FILE_RANGE_WRITE).
325 sync Calls sync(2) to flush all filesystems' in-core data to disk.
327 syncfs Calls syncfs(2) to flush this filesystem's in-core data to disk.
329 resvsp offset length
331 Allocates reserved, unwritten space for part of a file using the
332 XFS_IOC_RESVSP system call described in the xfsctl(3) manual
333 page.
334 unresvsp offset length
336 Frees reserved space for part of a file using the
337 XFS_IOC_UNRESVSP system call described in the xfsctl(3) manual
338 page.
339 falloc [ -k ] offset length
341 Allocates reserved, unwritten space for part of a file using the
342 fallocate routine as described in the fallocate(2) manual page.
343 -k will set the FALLOC_FL_KEEP_SIZE flag as described in
344 fallocate(2).
345 fcollapse offset length
347 Call fallocate with FALLOC_FL_COLLAPSE_RANGE flag as described
348 in the fallocate(2) manual page to de-allocates blocks and elim‐
349 inates the hole created in this process by shifting data blocks
350 into the hole.
351 finsert offset length
353 Call fallocate with FALLOC_FL_INSERT_RANGE flag as described in
354 the fallocate(2) manual page to create the hole by shifting data
355 blocks.
356 fpunch offset length
358 Punches (de-allocates) blocks in the file by calling fallocate
359 with the FALLOC_FL_PUNCH_HOLE flag as described in the fallo‐
360 cate(2) manual page.
361 funshare offset length
363 Call fallocate with FALLOC_FL_UNSHARE_RANGE flag as described in
364 the fallocate(2) manual page to unshare all shared blocks within
365 the range.
366 fzero offset length
368 Call fallocate with FALLOC_FL_ZERO_RANGE flag as described in
369 the fallocate(2) manual page to allocate and zero blocks within
370 the range.
371 zero offset length
373 Call xfsctl with XFS_IOC_ZERO_RANGE as described in the
374 xfsctl(3) manual page to allocate and zero blocks within the
375 range.
376 truncate offset
378 Truncates the current file at the given offset using ftrun‐
379 cate(2).
380 sendfile -i srcfile | -f N [ offset length ]
382 On platforms which support it, allows a direct in-kernel copy
383 between two file descriptors. The current open file is the tar‐
384 get, the source must be specified as another open file (-f) or
385 by path (-i).
386 readdir [ -v ] [ -o offset ] [ -l length ]
388 Read a range of directory entries from a given offset of a
389 directory.
390 -v verbose mode - dump dirent content as defined in read‐
391 dir(3)
392 -o specify starting offset
393 -l specify total length to read (in bytes)
394 seek -a | -d | -h [ -r ] [ -s ] offset
396 On platforms that support the lseek(2) SEEK_DATA and SEEK_HOLE
397 options, display the offsets of the specified segments.
398 -a Display both data and hole segments starting at the spec‐
399 ified offset.
400 -d Display the data segment starting at the specified off‐
401 set.
402 -h Display the hole segment starting at the specified off‐
403 set.
404 -r Recursively display all the specified segments starting
405 at the specified offset.
406 -s Display the starting lseek(2) offset. This offset will be
407 a calculated value when both data and holes are displayed
408 together or performing a recusively display.
409 reflink [ -C ] [ -q ] src_file [src_offset dst_offset length]
411 On filesystems that support the FICLONERANGE or
412 BTRFS_IOC_CLONE_RANGE ioctls, map length bytes at offset
413 dst_offset in the open file to the same physical blocks that are
414 mapped at offset src_offset in the file src_file , replacing any
415 contents that may already have been there. If a program writes
416 into a reflinked block range of either file, the dirty blocks
417 will be cloned, written to, and remapped ("copy on write") in
418 the affected file, leaving the other file(s) unchanged. If
419 src_offset, dst_offset, and length are omitted, all contents of
420 src_file will be reflinked into the open file.
421 -C Print timing statistics in a condensed format.
422 -q Do not print timing statistics at all.
423 dedupe [ -C ] [ -q ] src_file src_offset dst_offset length
425 On filesystems that support the FIDEDUPERANGE or
426 BTRFS_IOC_FILE_EXTENT_SAME ioctls, map length bytes at offset
427 dst_offset in the open file to the same physical blocks that are
428 mapped at offset src_offset in the file src_file , but only if
429 the contents of both ranges are identical. This is known as
430 block-based deduplication. If a program writes into a reflinked
431 block range of either file, the dirty blocks will be cloned,
432 written to, and remapped ("copy on write") in the affected file,
433 leaving the other file(s) unchanged.
434 -C Print timing statistics in a condensed format.
435 -q Do not print timing statistics at all.
436 copy_range [ -s src_offset ] [ -d dst_offset ] [ -l length ] src_file
438 On filesystems that support the copy_file_range(2) system call,
439 copies data from the src_file into the open file. If src_off‐
440 set, dst_offset, and length are omitted the contents of src_file
441 will be copied to the beginning of the open file, overwriting
442 any data already there.
443 -s Copy data from src_file beginning from src_offset.
444 -d Copy data into the open file beginning at dst_offset.
445 -l Copy up to length bytes of data.
446 utimes atime_sec atime_nsec mtime_sec mtime_nsec
448 The utimes command changes the atime and mtime of the current
449 file. sec uses UNIX timestamp notation and is the seconds
450 elapsed since 1970-01-01 00:00:00 UTC. nsec is the nanoseconds
451 since the sec. This value needs to be in the range 0-999999999
452 with UTIME_NOW and UTIME_OMIT being exceptions. Each (sec,
453 nsec) pair constitutes a single timestamp value.
454 swapext donor_file
456 Swaps extent forks between files. The current open file is the
457 target. The donor file is specified by path. Note that file data
458 is not copied (file content moves with the fork(s)).
459
462 mmap [ N | [[ -rwxS ] [-s size ] offset length ]]
463 With no arguments, mmap shows the current mappings. Specifying a
464 single numeric argument N sets the current mapping. If two argu‐
465 ments are specified (a range specified by offset and length), a
466 new mapping is created spanning the range, and the protection
467 mode can be given as a combination of PROT_READ (-r), PROT_WRITE
468 (-w), and PROT_EXEC (-x). The mapping will be created with the
469 MAP_SHARED flag by default, or with the Linux specific (MAP_SYNC
470 | MAP_SHARED_VALIDATE) flags if -S is given. -s size is used to
471 do a mmap(size) && munmap(size) operation at first, try to
472 reserve some extendible free memory space, if size is bigger
473 than length parameter. But there's not guarantee that the memory
474 after length ( up to size ) will stay free. e.g. "mmap -rw -s
475 8192 1024" will mmap 0 ~ 1024 bytes memory, but try to reserve
476 1024 ~ 8192 free space(no guarantee). This free space will help‐
477 ful for "mremap 8192" without MREMAP_MAYMOVE flag.
478 mm See the mmap command.
480 mremap [ -f <new_address> ] [ -m ] new_length
482 Changes the current mapping size to new_length. Whether the
483 mapping may be moved is controlled by the flags passed;
484 MREMAP_FIXED (-f), or MREMAP_MAYMOVE (-m). new_length specifies
485 a page-aligned address to which the mapping must be moved. It
486 can be set to 139946004389888, 4096k or 1g etc.
487 mrm See the mremap command.
489 munmap Unmaps the current memory mapping.
491 mu See the munmap command.
493 mread [ -f | -v ] [ -r ] [ offset length ]
495 Accesses a segment of the current memory mapping, optionally
496 dumping it to the standard output stream (with -v or -f option)
497 for inspection. The accesses are performed sequentially from the
498 start offset by default, but can also be done from the end back‐
499 wards through the mapping if the -r option in specified. The
500 two verbose modes differ only in the relative offsets they dis‐
501 play, the -f option is relative to file start, whereas -v shows
502 offsets relative to the start of the mapping.
503 mr See the mread command.
505 mwrite [ -r ] [ -S seed ] [ offset length ]
507 Stores a byte into memory for a range within a mapping. The
508 default stored value is 'X', repeated to fill the range speci‐
509 fied, but this can be changed using the -S option. The memory
510 stores are performed sequentially from the start offset by
511 default, but can also be done from the end backwards through the
512 mapping if the -r option in specified.
513 mw See the mwrite command.
515 msync [ -i ] [ -a | -s ] [ offset length ]
517 Writes all modified copies of pages over the specified range (or
518 entire mapping if no range specified) to their backing storage
519 locations. Also, optionally invalidates (-i) so that subsequent
520 references to the pages will be obtained from their backing
521 storage locations (instead of cached copies). The flush can be
522 done synchronously (-s) or asynchronously (-a).
523 ms See the msync command.
525 madvise [ -d | -r | -s | -w ] [ offset length ]
527 Modifies page cache behavior when operating on the current map‐
528 ping. The range arguments are required by some advise commands
529 ([*] below). With no arguments, the POSIX_MADV_NORMAL advice is
530 implied (default readahead).
531 -d the pages will not be needed (POSIX_MADV_DONTNEED[*]).
532 -r expect random page references (POSIX_MADV_RANDOM), which
533 sets readahead to zero.
534 -s expect sequential page references (POSIX_MADV_SEQUEN‐
535 TIAL), which doubles the default readahead on the file.
536 -w advises the specified pages will be needed again
537 (POSIX_MADV_WILLNEED[*]) which forces the maximum reada‐
538 head.
539 mincore
541 Dumps a list of pages or ranges of pages that are currently in
542 core, for the current memory mapping.
543
546 help [ command ]
547 Display a brief description of one or all commands.
548 print Display a list of all open files and memory mapped regions. The
550 current file and current mapping are distinguishable from any
551 others.
552 p See the print command.
554 quit Exit xfs_io.
556 q See the quit command.
558 lsattr [ -R | -D | -a | -v ]
560 List extended inode flags on the currently open file. If the -R
561 option is specified, a recursive descent is performed for all
562 directory entries below the currently open file (-D can be used
563 to restrict the output to directories only). This is a depth
564 first descent, it does not follow symlinks and it also does not
565 cross mount points.
566 chattr [ -R | -D ] [ +/-riasAdtPneEfSxC ]
568 Change extended inode flags on the currently open file. The -R
569 and -D options have the same meaning as above. The mapping
570 between each letter and the inode flags (refer to xfsctl(3) for
571 the full list) is available via the help command.
572 freeze Suspend all write I/O requests to the filesystem of the current
574 file. Only available in expert mode and requires privileges.
575 thaw Undo the effects of a filesystem freeze operation. Only avail‐
577 able in expert mode and requires privileges.
578 flink path
580 Link the currently open file descriptor into the filesystem
581 namespace.
582 inject [ tag ]
584 Inject errors into a filesystem to observe filesystem behavior
585 at specific points under adverse conditions. Without the tag
586 argument, displays the list of error tags available. Only
587 available in expert mode and requires privileges.
588 resblks [ blocks ]
590 Get and/or set count of reserved filesystem blocks using the
591 XFS_IOC_GET_RESBLKS or XFS_IOC_SET_RESBLKS system calls. Note
592 -- this can be useful for exercising out of space behavior.
593 Only available in expert mode and requires privileges.
594 shutdown [ -f ]
596 Force the filesystem to shutdown (with or without flushing the
597 log). Only available in expert mode and requires privileges.
598 stat [ -v|-r ]
600 Selected statistics from stat(2) and the XFS_IOC_GETXATTR system
601 call on the current file. If the -v option is specified, the
602 atime (last access), mtime (last modify), and ctime (last
603 change) timestamps are also displayed. The -r option dumps raw
604 fields from the stat structure.
605 statx [ -v|-r ][ -m basic | -m all | -m <mask> ][ -FD ]
607 Selected statistics from stat(2) and the XFS_IOC_GETXATTR system
608 call on the current file.
609 -v Show timestamps.
610 -r Dump raw statx structure values.
611 -m basic
612 Set the field mask for the statx call to
613 STATX_BASIC_STATS.
614 -m all
615 Set the the field mask for the statx call to STATX_ALL
616 (default).
617 -m <mask>
618 Specify a numeric field mask for the statx call.
619 -F Force the attributes to be synced with the server.
620 -D Don't sync attributes with the server.
621 statfs Selected statistics from statfs(2) and the XFS_IOC_FSGEOMETRY
623 system call on the filesystem where the current file resides.
624 chproj [ -R|-D ]
626 Modifies the project identifier associated with the current
627 path. The -R option will recursively descend if the current path
628 is a directory. The -D option will also recursively descend,
629 only setting modifying projects on subdirectories. See the
630 xfs_quota(8) manual page for more information about project
631 identifiers.
632 lsproj [ -R|-D ]
634 Displays the project identifier associated with the current
635 path. The -R and -D options behave as described above, in
636 chproj.
637 parent [ -cpv ]
639 By default this command prints out the parent inode numbers,
640 inode generation numbers and basenames of all the hardlinks
641 which point to the inode of the current file.
642 -p the output is similar to the default output except path‐
643 names up to the mount-point are printed out instead of
644 the component name.
645 -c the file's filesystem will check all the parent
646 attributes for consistency.
647 -v verbose output will be printed.
648 [NOTE: Not currently operational on Linux.]
649 inode [ [ -n ] number ] [ -v ]
651 The inode command queries physical information about an inode.
652 With no arguments, it will return 1 or 0, indicating whether or
653 not any inode numbers greater than 32 bits are currently in use
654 in the filesystem. If given an inode number as an argument, the
655 command will return the same inode number if it is in use, or 0
656 if not. With -n number , the next used inode number after this
657 number will be returned, or zero if the supplied inode number is
658 the highest one in use. With -v the command will also report the
659 number of bits (32 or 64) used by the inode number printed in
660 the result; if no inode number was specified on the command
661 line, the maximum possible inode number in the system will be
662 printed along with its size.
663 set_encpolicy [ -c mode ] [ -n mode ] [ -f flags ] [ -v version ] [
665 keydesc ]
666 On filesystems that support encryption, assign an encryption
667 policy to the current file. keydesc is a 16-byte hex string
668 which identifies the encryption key to use. If not specified, a
669 "default" key descriptor of all 0's will be used.
670 -c mode
671 contents encryption mode (e.g. AES-256-XTS)
672 -n mode
673 filenames encryption mode (e.g. AES-256-CTS)
674 -f flags
675 policy flags (numeric)
676 -v version
677 version of policy structure (numeric)
678 get_encpolicy
680 On filesystems that support encryption, display the encryption
681 policy of the current file.
682 scrub type [ agnumber | ino gen ]
684 Scrub internal XFS filesystem metadata. The type parameter
685 specifies which type of metadata to scrub. For AG metadata, one
686 AG number must be specified. For file metadata, the scrub is
687 applied to the open file unless the inode number and generation
688 number are specified.
689 log_writes -d device -m mark
691 Create a mark named mark in the dm-log-writes log specified by
692 device. This is intended to be equivalent to the shell command:
693 dmsetup message device 0 mark mark
695 lw See the log_writes command.
697 label [ -c | -s label ]
699 On filesystems that support online label manipulation, get, set,
700 or clear the filesystem label. With no options, print the cur‐
701 rent filesystem label. The -c option clears the filesystem
702 label by setting it to the null string. The -s label option
703 sets the filesystem label to label. If the label is longer than
704 the filesystem will accept, xfs_io will print an error message.
705 XFS filesystem labels can be at most 12 characters long.
706
708 mkfs.xfs(8), xfsctl(3), xfs_bmap(8), xfs_db(8), xfs(5), fdatasync(2),
709 fstat(2), fstatfs(2), fsync(2), ftruncate(2), futimens(3), mmap(2),
710 msync(2), open(2), pread(2), pwrite(2), readdir(3), dmsetup(8).
711 xfs_io(8)