file [ N ]
Display a list of all open files and (optionally) switch
to an alternate current open file.
open [[ -acdfrstRTPL ] path ]
Closes the current file, and opens the file specified by
path instead. Without any arguments, displays statistics
about the current file - see the stat command.
-a opens append-only (O_APPEND).
-d opens for direct I/O (O_DIRECT).
-f creates the file if it doesn't already exist
(O_CREAT).
-r opens read-only (O_RDONLY).
-s opens for synchronous I/O (O_SYNC).
-t truncates on open (O_TRUNC).
-n opens in non-blocking mode if possible
(O_NONBLOCK).
-T create a temporary file not linked into the
filesystem namespace (O_TMPFILE). The pathname
passed must refer to a directory which is treated
as virtual parent for the newly created invisible
file. Can not be used together with the -r option.
-R marks the file as a realtime XFS file after opening
it, if it is not already marked as such.
-P opens the path as a referent only (O_PATH). This
is incompatible with other flags specifying other
O_xxx flags apart from -L.
-L doesn't follow symlinks (O_NOFOLLOW). This is
incompatible with other flags specifying other
O_xxx flags apart from -P.
o See the open command.
close Closes the current open file, marking the next open file
as current (if one exists).
c See the close command.
chmod -r | -w
Change the mode of the currently open file. The -r option
will set the file permissions to read-only (0444), whilst
the -w option will set the file permissions to read-write
(0644). This allows xfs_io to set up mismatches between
the file permissions and the open file descriptor
read/write mode to exercise permission checks inside
various syscalls.
pread [ -b bsize ] [ -qv ] [ -FBR [ -Z seed ] ] [ -V vectors ]
offset length
Reads a range of bytes in a specified blocksize from the
given offset.
-b can be used to set the blocksize into which the
read(2) requests will be split. The default
blocksize is 4096 bytes.
-q quiet mode, do not write anything to standard
output.
-v dump the contents of the buffer after reading, by
default only the count of bytes actually read is
dumped.
-F read the buffers in a forward sequential direction.
-B read the buffers in a reverse sequential direction.
-R read the buffers in the give range in a random
order.
-Z seed
specify the random number seed used for random
reads.
-V vectors
Use the vectored IO read syscall preadv(2) with a
number of blocksize length iovecs. The number of
iovecs is set by the vectors parameter.
r See the pread command.
pwrite [ -i file ] [ -qdDwNOW ] [ -s skip ] [ -b size ] [ -S seed
] [ -FBR [ -Z zeed ] ] [ -V vectors ] offset length
Writes a range of bytes in a specified blocksize from the
given offset. The bytes written can be either a set
pattern or read in from another file before writing.
-i allows an input file to be specified as the source
of the data to be written.
-q quiet mode, do not write anything to standard
output.
-d causes direct I/O, rather than the usual buffered
I/O, to be used when reading the input file.
-w call fdatasync(2) once all writes are complete
(included in timing results)
-N Perform the pwritev2(2) call with RWF_NOWAIT.
-D Perform the pwritev2(2) call with RWF_DSYNC.
-O perform pwrite once and return the (maybe partial)
bytes written.
-W call fsync(2) once all writes are complete
(included in timing results)
-s specifies the number of bytes to skip from the
start of the input file before starting to read.
-b used to set the blocksize into which the write(2)
requests will be split. The default blocksize is
4096 bytes.
-S used to set the (repeated) fill pattern which is
used when the data to write is not coming from a
file. The default buffer fill pattern value is
0xcdcdcdcd.
-F write the buffers in a forward sequential
direction.
-B write the buffers in a reverse sequential
direction.
-R write the buffers in the give range in a random
order.
-Z seed
specify the random number seed used for random
write
-V vectors
Use the vectored IO write syscall pwritev(2) with a
number of blocksize length iovecs. The number of
iovecs is set by the vectors parameter.
w See the pwrite command.
bmap [ -adelpv ] [ -n nx ]
Prints the block mapping for the current open file. Refer
to the xfs_bmap(8) manual page for complete documentation.
fiemap [ -alv ] [ -n nx ] [ offset [ len ]]
Prints the block mapping for the current open file using
the fiemap ioctl. Options behave as described in the
xfs_bmap(8) manual page.
Optionally, this command also supports passing the start
offset from where to begin the mapping and the length of
that region. The kernel will return any full extents
which intersect with the requested range, and the fiemap
command will print them in their entirety. If the
requested range starts or ends in a hole, fiemap will
print the hole, truncated to the requested range.
extsize [ -R | -D ] [ value ]
Display and/or modify the preferred extent size used when
allocating space for the currently open file. If the -R
option is specified, a recursive descent is performed for
all directory entries below the currently open file (-D
can be used to restrict the output to directories only).
If the target file is a directory, then the inherited
extent size is set for that directory (new files created
in that directory inherit that extent size). The value
should be specified in bytes, or using one of the usual
units suffixes (k, m, g, b, etc). The extent size is
always reported in units of bytes.
cowextsize [ -R | -D ] [ value ]
Display and/or modify the preferred copy-on-write extent
size used when allocating space for the currently open
file. If the -R option is specified, a recursive descent
is performed for all directory entries below the currently
open file (-D can be used to restrict the output to
directories only). If the target file is a directory,
then the inherited CoW extent size is set for that
directory (new files created in that directory inherit
that CoW extent size). The value should be specified in
bytes, or using one of the usual units suffixes (k, m, g,
b, etc). The extent size is always reported in units of
bytes.
allocsp size 0
Sets the size of the file to size and zeroes any
additional space allocated using the
XFS_IOC_ALLOCSP/XFS_IOC_FREESP system call described in
the xfsctl(3) manual page. allocsp and freesp do exactly
the same thing.
freesp size 0
See the allocsp command.
fadvise [ -r | -s | [[ -d | -n | -w ] offset length ]]
On platforms which support it, allows hints be given to
the system regarding the expected I/O patterns on the
file. The range arguments are required by some advise
commands ([*] below), and the others must have no range
arguments. With no arguments, the POSIX_FADV_NORMAL
advice is implied (default readahead).
-d the data will not be accessed again in the near
future (POSIX_FADV_DONTNEED[*]).
-n data will be accessed once and not be reused
(POSIX_FADV_NOREUSE[*]).
-r expect access to data in random order
(POSIX_FADV_RANDOM), which sets readahead to zero.
-s expect access to data in sequential order
(POSIX_FADV_SEQUENTIAL), which doubles the default
readahead on the file.
-w advises the specified data will be needed again
(POSIX_FADV_WILLNEED[*]) which forces the maximum
readahead.
fdatasync
Calls fdatasync(2) to flush the file's in-core data to
disk.
fsync Calls fsync(2) to flush all in-core file state to disk.
s See the fsync command.
sync_range [ -a | -b | -w ] offset length
On platforms which support it, allows control of syncing a
range of the file to disk. With no options,
SYNC_FILE_RANGE_WRITE is implied on the range supplied.
-a wait for IO in the given range to finish after
writing (SYNC_FILE_RANGE_WAIT_AFTER).
-b wait for IO in the given range to finish before
writing (SYNC_FILE_RANGE_WAIT_BEFORE).
-w start writeback of dirty data in the given range
(SYNC_FILE_RANGE_WRITE).
sync Calls sync(2) to flush all filesystems' in-core data to
disk.
syncfs Calls syncfs(2) to flush this filesystem's in-core data to
disk.
resvsp offset length
Allocates reserved, unwritten space for part of a file
using the XFS_IOC_RESVSP system call described in the
xfsctl(3) manual page.
unresvsp offset length
Frees reserved space for part of a file using the
XFS_IOC_UNRESVSP system call described in the xfsctl(3)
manual page.
falloc [ -k ] offset length
Allocates reserved, unwritten space for part of a file
using the fallocate routine as described in the
fallocate(2) manual page.
-k will set the FALLOC_FL_KEEP_SIZE flag as described
in fallocate(2).
fcollapse offset length
Call fallocate with FALLOC_FL_COLLAPSE_RANGE flag as
described in the fallocate(2) manual page to de-allocates
blocks and eliminates the hole created in this process by
shifting data blocks into the hole.
finsert offset length
Call fallocate with FALLOC_FL_INSERT_RANGE flag as
described in the fallocate(2) manual page to create the
hole by shifting data blocks.
fpunch offset length
Punches (de-allocates) blocks in the file by calling
fallocate with the FALLOC_FL_PUNCH_HOLE flag as described
in the fallocate(2) manual page.
funshare offset length
Call fallocate with FALLOC_FL_UNSHARE_RANGE flag as
described in the fallocate(2) manual page to unshare all
shared blocks within the range.
fzero [ -k ] offset length
Call fallocate with FALLOC_FL_ZERO_RANGE flag as described
in the fallocate(2) manual page to allocate and zero
blocks within the range. With the -k option, use the
FALLOC_FL_KEEP_SIZE flag as well.
zero offset length
Call xfsctl with XFS_IOC_ZERO_RANGE as described in the
xfsctl(3) manual page to allocate and zero blocks within
the range.
truncate offset
Truncates the current file at the given offset using
ftruncate(2).
sendfile [ -q ] -i srcfile | -f N [ offset length ]
On platforms which support it, allows a direct in-kernel
copy between two file descriptors. The current open file
is the target, the source must be specified as another
open file (-f) or by path (-i).
-q quiet mode, do not write anything to standard
output.
readdir [ -v ] [ -o offset ] [ -l length ]
Read a range of directory entries from a given offset of a
directory.
-v verbose mode - dump dirent content as defined in
readdir(3)
-o specify starting offset
-l specify total length to read (in bytes)
seek -a | -d | -h [ -r ] [ -s ] offset
On platforms that support the lseek(2) SEEK_DATA and
SEEK_HOLE options, display the offsets of the specified
segments.
-a Display both data and hole segments starting at the
specified offset.
-d Display the data segment starting at the specified
offset.
-h Display the hole segment starting at the specified
offset.
-r Recursively display all the specified segments
starting at the specified offset.
-s Display the starting lseek(2) offset. This offset
will be a calculated value when both data and holes
are displayed together or performing a recusively
display.
reflink [ -C ] [ -q ] src_file [src_offset dst_offset length]
On filesystems that support the FICLONERANGE or
BTRFS_IOC_CLONE_RANGE ioctls, map length bytes at offset
dst_offset in the open file to the same physical blocks
that are mapped at offset src_offset in the file src_file
, replacing any contents that may already have been there.
If a program writes into a reflinked block range of either
file, the dirty blocks will be cloned, written to, and
remapped ("copy on write") in the affected file, leaving
the other file(s) unchanged. If src_offset, dst_offset,
and length are omitted, all contents of src_file will be
reflinked into the open file.
-C Print timing statistics in a condensed format.
-q Do not print timing statistics at all.
dedupe [ -C ] [ -q ] src_file src_offset dst_offset length
On filesystems that support the FIDEDUPERANGE or
BTRFS_IOC_FILE_EXTENT_SAME ioctls, map length bytes at
offset dst_offset in the open file to the same physical
blocks that are mapped at offset src_offset in the file
src_file , but only if the contents of both ranges are
identical. This is known as block-based deduplication.
If a program writes into a reflinked block range of either
file, the dirty blocks will be cloned, written to, and
remapped ("copy on write") in the affected file, leaving
the other file(s) unchanged.
-C Print timing statistics in a condensed format.
-q Do not print timing statistics at all.
copy_range [ -s src_offset ] [ -d dst_offset ] [ -l length ]
src_file | -f N
On filesystems that support the copy_file_range(2) system
call, copies data from the source file into the current
open file. The source must be specified either by path
(src_file) or as another open file (-f). If length is not
specified, this command copies data from src_offset to the
end of src_file into the dst_file at dst_offset.
-s Copy data from src_file beginning from src_offset.
-d Copy data into the open file beginning at
dst_offset.
-l Copy up to length bytes of data.
swapext donor_file
Swaps extent forks between files. The current open file is
the target. The donor file is specified by path. Note that
file data is not copied (file content moves with the
fork(s)).
set_encpolicy [ -c mode ] [ -n mode ] [ -f flags ] [ -v version ]
[ keyspec ]
On filesystems that support encryption, assign an
encryption policy to the current file. keyspec is a hex
string which specifies the encryption key to use. For v1
encryption policies, keyspec must be a 16-character hex
string (8 bytes). For v2 policies, keyspec must be a
32-character hex string (16 bytes). If unspecified, an
all-zeroes value is used.
-c mode
contents encryption mode (e.g. AES-256-XTS)
-n mode
filenames encryption mode (e.g. AES-256-CTS)
-f flags
policy flags (numeric)
-v version
policy version. Defaults to 1 or 2 depending on
the length of keyspec; or to 1 if keyspec is
unspecified.
get_encpolicy [ -1 ] [ -t ]
On filesystems that support encryption, display the
encryption policy of the current file.
-1 Use only the old ioctl to get the encryption
policy. This only works if the file has a v1
encryption policy.
-t Test whether v2 encryption policies are supported.
Prints "supported", "unsupported", or an error
message.
add_enckey [ -d descriptor ] [ -k key_id ]
On filesystems that support encryption, add an encryption
key to the filesystem containing the currently open file.
By default, the raw key in binary (typically 64 bytes
long) is read from standard input.
-d descriptor
key descriptor, as a 16-character hex string (8
bytes). If given, the key will be available for
use by v1 encryption policies that use this
descriptor. Otherwise, the key is added as a v2
policy key, and on success the resulting "key
identifier" will be printed.
-k key_id
ID of kernel keyring key of type "fscrypt-
provisioning". If given, the raw key will be taken
from here rather than from standard input.
rm_enckey [ -a ] keyspec
On filesystems that support encryption, remove an
encryption key from the filesystem containing the
currently open file. keyspec is a hex string specifying
the key to remove, as a 16-character "key descriptor" or a
32-character "key identifier".
-a Remove the key for all users who have added it, not
just the current user. This is a privileged
operation.
enckey_status keyspec
On filesystems that support encryption, display the status
of an encryption key. keyspec is a hex string specifying
the key for which to display the status, as a 16-character
"key descriptor" or a 32-character "key identifier".
lsattr [ -R | -D | -a | -v ]
List extended inode flags on the currently open file. If
the -R option is specified, a recursive descent is
performed for all directory entries below the currently
open file (-D can be used to restrict the output to
directories only). This is a depth first descent, it does
not follow symlinks and it also does not cross mount
points.
The current inode flag letters are documented below.
Please refer to the ioctl_xfs_fsgetxattr(2) documentation
for more details about what they mean.
r realtime file (XFS_XFLAG_REALTIME)
p prealloc (XFS_XFLAG_PREALLOC)
i immutable (XFS_XFLAG_IMMUTABLE)
a append only (XFS_XFLAG_APPEND)
s synchronous file writes (XFS_XFLAG_SYNC)
A noatime (XFS_XFLAG_NOATIME)
d nodump (XFS_XFLAG_NODUMP)
t inherit realtime flag (XFS_XFLAG_RTINHERIT)"
P inherit project id (XFS_XFLAG_PROJINHERIT)
n no symlink creation (XFS_XFLAG_NOSYMLINKS)
e extent size hint (XFS_XFLAG_EXTSIZE)
E inherit extent size hint (XFS_XFLAG_EXTSZINHERIT)
f nodefrag (XFS_XFLAG_NODEFRAG)
S filestream allocator (XFS_XFLAG_FILESTREAM)
x direct access persistent memory (XFS_XFLAG_DAX)
C copy on write extent hint (XFS_XFLAG_COWEXTSIZE)
X has extended attributes (XFS_XFLAG_HASATTR)
chattr [ -R | -D ] [ +/-riasAdtPneEfSxC ]
Change extended inode flags on the currently open file.
The -R and -D options have the same meaning as above.
See the lsattr command above for the list of inode flag
letters.
flink path
Link the currently open file descriptor into the
filesystem namespace.
stat [ -v|-r ]
Selected statistics from stat(2) and the XFS_IOC_GETXATTR
system call on the current file. If the -v option is
specified, the atime (last access), mtime (last modify),
and ctime (last change) timestamps are also displayed.
The -r option dumps raw fields from the stat structure.
statx [ -v|-r ][ -m basic | -m all | -m <mask> ][ -FD ]
Selected statistics from stat(2) and the XFS_IOC_GETXATTR
system call on the current file.
-v Show timestamps.
-r Dump raw statx structure values.
-m basic
Set the field mask for the statx call to
STATX_BASIC_STATS.
-m all
Set the the field mask for the statx call to
STATX_ALL (default).
-m <mask>
Specify a numeric field mask for the statx call.
-F Force the attributes to be synced with the server.
-D Don't sync attributes with the server.
chproj [ -R|-D ]
Modifies the project identifier associated with the
current path. The -R option will recursively descend if
the current path is a directory. The -D option will also
recursively descend, only setting modifying projects on
subdirectories. See the xfs_quota(8) manual page for more
information about project identifiers.
lsproj [ -R|-D ]
Displays the project identifier associated with the
current path. The -R and -D options behave as described
above, in chproj.
parent [ -cpv ]
By default this command prints out the parent inode
numbers, inode generation numbers and basenames of all the
hardlinks which point to the inode of the current file.
-p the output is similar to the default output except
pathnames up to the mount-point are printed out
instead of the component name.
-c the file's filesystem will check all the parent
attributes for consistency.
-v verbose output will be printed.
[NOTE: Not currently operational on Linux.]
utimes atime_sec atime_nsec mtime_sec mtime_nsec
The utimes command changes the atime and mtime of the
current file. sec uses UNIX timestamp notation and is the
seconds elapsed since 1970-01-01 00:00:00 UTC. nsec is
the nanoseconds since the sec. This value needs to be in
the range 0-999999999 with UTIME_NOW and UTIME_OMIT being
exceptions. Each (sec, nsec) pair constitutes a single
timestamp value.
