Merge tag 'xfs-5.3-merge-13' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

   blockdev/index

   ext4

   binderfs

   xfs

   pm/index

   thunderbolt

   LSM/index

.. SPDX-License-Identifier: GPL-2.0

======================

The SGI XFS Filesystem

======================

=============

When mounting an XFS filesystem, the following options are accepted.

For boolean mount options, the names with the (*) suffix is the

default behaviour.

  allocsize=size

	Sets the buffered I/O end-of-file preallocation size when

	preallocation size, which uses a set of heuristics to

	optimise the preallocation size based on the current

	allocation patterns within the file and the access patterns

	to the file. Specifying a fixed allocsize value turns off

	to the file. Specifying a fixed ``allocsize`` value turns off

	the dynamic behaviour.

  attr2

  noattr2

  attr2 or noattr2

	The options enable/disable an "opportunistic" improvement to

	be made in the way inline extended attributes are stored

	on-disk.  When the new form is used for the first time when

	attr2 is selected (either when setting or removing extended

	``attr2`` is selected (either when setting or removing extended

	attributes) the on-disk superblock feature bit field will be

	updated to reflect this format being in use.

	The default behaviour is determined by the on-disk feature

	bit indicating that attr2 behaviour is active. If either

	mount option it set, then that becomes the new default used

	bit indicating that ``attr2`` behaviour is active. If either

	mount option is set, then that becomes the new default used

	by the filesystem.

	CRC enabled filesystems always use the attr2 format, and so

	will reject the noattr2 mount option if it is set.

	CRC enabled filesystems always use the ``attr2`` format, and so

	will reject the ``noattr2`` mount option if it is set.

  discard

  nodiscard (*)

  discard or nodiscard (default)

	Enable/disable the issuing of commands to let the block

	device reclaim space freed by the filesystem.  This is

	useful for SSD devices, thinly provisioned LUNs and virtual

	machine images, but may have a performance impact.

	Note: It is currently recommended that you use the fstrim

	application to discard unused blocks rather than the discard

	Note: It is currently recommended that you use the ``fstrim``

	application to ``discard`` unused blocks rather than the ``discard``

	mount option because the performance impact of this option

	is quite severe.

  grpid/bsdgroups

  nogrpid/sysvgroups (*)

  grpid/bsdgroups or nogrpid/sysvgroups (default)

	These options define what group ID a newly created file

	gets.  When grpid is set, it takes the group ID of the

	gets.  When ``grpid`` is set, it takes the group ID of the

	directory in which it is created; otherwise it takes the

	fsgid of the current process, unless the directory has the

	setgid bit set, in which case it takes the gid from the

	parent directory, and also gets the setgid bit set if it is

	``fsgid`` of the current process, unless the directory has the

	``setgid`` bit set, in which case it takes the ``gid`` from the

	parent directory, and also gets the ``setgid`` bit set if it is

	a directory itself.

  filestreams

	across the entire filesystem rather than just on directories

	configured to use it.

  ikeep

  noikeep (*)

	When ikeep is specified, XFS does not delete empty inode

	clusters and keeps them around on disk.  When noikeep is

  ikeep or noikeep (default)

	When ``ikeep`` is specified, XFS does not delete empty inode

	clusters and keeps them around on disk.  When ``noikeep`` is

	specified, empty inode clusters are returned to the free

	space pool.

  inode32

  inode64 (*)

	When inode32 is specified, it indicates that XFS limits

  inode32 or inode64 (default)

	When ``inode32`` is specified, it indicates that XFS limits

	inode creation to locations which will not result in inode

	numbers with more than 32 bits of significance.

	When inode64 is specified, it indicates that XFS is allowed

	When ``inode64`` is specified, it indicates that XFS is allowed

	to create inodes at any location in the filesystem,

	including those which will result in inode numbers occupying

	more than 32 bits of significance.

	inode32 is provided for backwards compatibility with older

	``inode32`` is provided for backwards compatibility with older

	systems and applications, since 64 bits inode numbers might

	cause problems for some applications that cannot handle

	large inode numbers.  If applications are in use which do

	not handle inode numbers bigger than 32 bits, the inode32

	not handle inode numbers bigger than 32 bits, the ``inode32``

	option should be specified.

  largeio

  nolargeio (*)

	If "nolargeio" is specified, the optimal I/O reported in

	st_blksize by stat(2) will be as small as possible to allow

  largeio or nolargeio (default)

	If ``nolargeio`` is specified, the optimal I/O reported in

	``st_blksize`` by **stat(2)** will be as small as possible to allow

	user applications to avoid inefficient read/modify/write

	I/O.  This is typically the page size of the machine, as

	this is the granularity of the page cache.

	If "largeio" specified, a filesystem that was created with a

	"swidth" specified will return the "swidth" value (in bytes)

	in st_blksize. If the filesystem does not have a "swidth"

	specified but does specify an "allocsize" then "allocsize"

	If ``largeio`` is specified, a filesystem that was created with a

	``swidth`` specified will return the ``swidth`` value (in bytes)

	in ``st_blksize``. If the filesystem does not have a ``swidth``

	specified but does specify an ``allocsize`` then ``allocsize``

	(in bytes) will be returned instead. Otherwise the behaviour

	is the same as if "nolargeio" was specified.

	is the same as if ``nolargeio`` was specified.

  logbufs=value

	Set the number of in-memory log buffers.  Valid numbers

	If the memory cost of 8 log buffers is too high on small

	systems, then it may be reduced at some cost to performance

	on metadata intensive workloads. The logbsize option below

	on metadata intensive workloads. The ``logbsize`` option below

	controls the size of each buffer and so is also relevant to

	this case.

	and 32768 (32k).  Valid sizes for version 2 logs also

	include 65536 (64k), 131072 (128k) and 262144 (256k). The

	logbsize must be an integer multiple of the log

	stripe unit configured at mkfs time.

	stripe unit configured at **mkfs(8)** time.

	The default value for for version 1 logs is 32768, while the

	default value for version 2 logs is MAX(32768, log_sunit).

  noalign

	Data allocations will not be aligned at stripe unit

	boundaries. This is only relevant to filesystems created

	with non-zero data alignment parameters (sunit, swidth) by

	mkfs.

	with non-zero data alignment parameters (``sunit``, ``swidth``) by

	**mkfs(8)**.

  norecovery

	The filesystem will be mounted without running log recovery.

	If the filesystem was not cleanly unmounted, it is likely to

	be inconsistent when mounted in "norecovery" mode.

	be inconsistent when mounted in ``norecovery`` mode.

	Some files or directories may not be accessible because of this.

	Filesystems mounted "norecovery" must be mounted read-only or

	Filesystems mounted ``norecovery`` must be mounted read-only or

	the mount will fail.

  nouuid

	Don't check for double mounted file systems using the file

	system uuid.  This is useful to mount LVM snapshot volumes,

	and often used in combination with "norecovery" for mounting

	system ``uuid``.  This is useful to mount LVM snapshot volumes,

	and often used in combination with ``norecovery`` for mounting

	read-only snapshots.

  noquota

  uquota/usrquota/uqnoenforce/quota

	User disk quota accounting enabled, and limits (optionally)

	enforced.  Refer to xfs_quota(8) for further details.

	enforced.  Refer to **xfs_quota(8)** for further details.

  gquota/grpquota/gqnoenforce

	Group disk quota accounting enabled and limits (optionally)

	enforced.  Refer to xfs_quota(8) for further details.

	enforced.  Refer to **xfs_quota(8)** for further details.

  pquota/prjquota/pqnoenforce

	Project disk quota accounting enabled and limits (optionally)

	enforced.  Refer to xfs_quota(8) for further details.

	enforced.  Refer to **xfs_quota(8)** for further details.

  sunit=value and swidth=value

	Used to specify the stripe unit and width for a RAID device

	block units. These options are only relevant to filesystems

	that were created with non-zero data alignment parameters.

	The sunit and swidth parameters specified must be compatible

	The ``sunit`` and ``swidth`` parameters specified must be compatible

	with the existing filesystem alignment characteristics.  In

	general, that means the only valid changes to sunit are

	increasing it by a power-of-2 multiple. Valid swidth values

	are any integer multiple of a valid sunit value.

	general, that means the only valid changes to ``sunit`` are

	increasing it by a power-of-2 multiple. Valid ``swidth`` values

	are any integer multiple of a valid ``sunit`` value.

	Typically the only time these mount options are necessary if

	after an underlying RAID device has had it's geometry

Deprecated Mount Options

========================

===========================     ================

  Name				Removal Schedule

  ----				----------------

===========================     ================

===========================     ================

Removed Mount Options

=====================

===========================     =======

  Name				Removed

  ----				-------

===========================	=======

  delaylog/nodelaylog		v4.0

  ihashsize			v4.0

  irixsgid			v4.0

  osyncisdsync/osyncisosync	v4.0

  barrier			v4.19

  nobarrier			v4.19

===========================     =======

sysctls

=======

  fs.xfs.inherit_sync		(Min: 0  Default: 1  Max: 1)

	Setting this to "1" will cause the "sync" flag set

	by the xfs_io(8) chattr command on a directory to be

	by the **xfs_io(8)** chattr command on a directory to be

	inherited by files in that directory.

  fs.xfs.inherit_nodump		(Min: 0  Default: 1  Max: 1)

	Setting this to "1" will cause the "nodump" flag set

	by the xfs_io(8) chattr command on a directory to be

	by the **xfs_io(8)** chattr command on a directory to be

	inherited by files in that directory.

  fs.xfs.inherit_noatime	(Min: 0  Default: 1  Max: 1)

	Setting this to "1" will cause the "noatime" flag set

	by the xfs_io(8) chattr command on a directory to be

	by the **xfs_io(8)** chattr command on a directory to be

	inherited by files in that directory.

  fs.xfs.inherit_nosymlinks	(Min: 0  Default: 1  Max: 1)

	Setting this to "1" will cause the "nosymlinks" flag set

	by the xfs_io(8) chattr command on a directory to be

	by the **xfs_io(8)** chattr command on a directory to be

	inherited by files in that directory.

  fs.xfs.inherit_nodefrag	(Min: 0  Default: 1  Max: 1)

	Setting this to "1" will cause the "nodefrag" flag set

	by the xfs_io(8) chattr command on a directory to be

	by the **xfs_io(8)** chattr command on a directory to be

	inherited by files in that directory.

  fs.xfs.rotorstep		(Min: 1  Default: 1  Max: 256)

 -error handlers:

	Defines the behavior for a specific error.

The filesystem behavior during an error can be set via sysfs files. Each

The filesystem behavior during an error can be set via ``sysfs`` files. Each

error handler works independently - the first condition met by an error handler

for a specific class will cause the error to be propagated rather than reset and

retried.

	handler configurations.

	Note: there is no guarantee that fail_at_unmount can be set while an

	unmount is in progress. It is possible that the sysfs entries are

	unmount is in progress. It is possible that the ``sysfs`` entries are

	removed by the unmounting filesystem before a "retry forever" error

	handler configuration causes unmount to hang, and hence the filesystem

	must be configured appropriately before unmount begins to prevent

Each filesystem has specific error class handlers that define the error

propagation behaviour for specific errors. There is also a "default" error

handler defined, which defines the behaviour for all errors that don't have

specific handlers defined. Where multiple retry constraints are configuredi for

specific handlers defined. Where multiple retry constraints are configured for

a single error, the first retry configuration that expires will cause the error

to be propagated. The handler configurations are found in the directory:

	Setting the value to "N" (where 0 < N < Max) will allow XFS to retry the

	operation for up to "N" seconds before propagating the error.

Note: The default behaviour for a specific error handler is dependent on both

**Note:** The default behaviour for a specific error handler is dependent on both

the class and error context. For example, the default values for

"metadata/ENODEV" are "0" rather than "-1" so that this error handler defaults

to "fail immediately" behaviour. This is done because ENODEV is a fatal,

These filesystems may be used for inspiration:

- ext2: see Documentation/filesystems/ext2.txt

- ext4: see Documentation/filesystems/ext4/

- xfs:  see Documentation/filesystems/xfs.txt

- xfs:  see Documentation/admin-guide/xfs.rst

Handling Media Errors

W:	http://xfs.org/

T:	git git://git.kernel.org/pub/scm/fs/xfs/xfs-linux.git

S:	Supported

F:	Documentation/filesystems/xfs.txt

F:	Documentation/admin-guide/xfs.rst

F:	Documentation/ABI/testing/sysfs-fs-xfs

F:	Documentation/filesystems/xfs.txt

F:	Documentation/filesystems/xfs-delayed-logging-design.txt

F:	Documentation/filesystems/xfs-self-describing-metadata.txt

F:	fs/xfs/

				   xfs_refcount_btree.o \

				   xfs_sb.o \

				   xfs_symlink_remote.o \

				   xfs_trans_inode.o \

				   xfs_trans_resv.o \

				   xfs_types.o \

				   )

				   xfs_rmap_item.o \

				   xfs_log_recover.o \

				   xfs_trans_ail.o \

				   xfs_trans_buf.o \

				   xfs_trans_inode.o

				   xfs_trans_buf.o

# optional features

xfs-$(CONFIG_XFS_QUOTA)		+= xfs_dquot.o \