linux/fs/xfs/Kconfig

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# SPDX-License-Identifier: GPL-2.0-only
config XFS_FS
tristate "XFS filesystem support"
[PATCH] BLOCK: Make it possible to disable the block layer [try #6] Make it possible to disable the block layer. Not all embedded devices require it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require the block layer to be present. This patch does the following: (*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev support. (*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls an item that uses the block layer. This includes: (*) Block I/O tracing. (*) Disk partition code. (*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS. (*) The SCSI layer. As far as I can tell, even SCSI chardevs use the block layer to do scheduling. Some drivers that use SCSI facilities - such as USB storage - end up disabled indirectly from this. (*) Various block-based device drivers, such as IDE and the old CDROM drivers. (*) MTD blockdev handling and FTL. (*) JFFS - which uses set_bdev_super(), something it could avoid doing by taking a leaf out of JFFS2's book. (*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and linux/elevator.h contingent on CONFIG_BLOCK being set. sector_div() is, however, still used in places, and so is still available. (*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and parts of linux/fs.h. (*) Makes a number of files in fs/ contingent on CONFIG_BLOCK. (*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK. (*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK is not enabled. (*) fs/no-block.c is created to hold out-of-line stubs and things that are required when CONFIG_BLOCK is not set: (*) Default blockdev file operations (to give error ENODEV on opening). (*) Makes some /proc changes: (*) /proc/devices does not list any blockdevs. (*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK. (*) Makes some compat ioctl handling contingent on CONFIG_BLOCK. (*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if given command other than Q_SYNC or if a special device is specified. (*) In init/do_mounts.c, no reference is made to the blockdev routines if CONFIG_BLOCK is not defined. This does not prohibit NFS roots or JFFS2. (*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return error ENOSYS by way of cond_syscall if so). (*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if CONFIG_BLOCK is not set, since they can't then happen. Signed-Off-By: David Howells <dhowells@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-10-01 02:45:40 +08:00
depends on BLOCK
select EXPORTFS
select LIBCRC32C
select FS_IOMAP
help
XFS is a high performance journaling filesystem which originated
on the SGI IRIX platform. It is completely multi-threaded, can
support large files and large filesystems, extended attributes,
variable block sizes, is extent based, and makes extensive use of
Btrees (directories, extents, free space) to aid both performance
and scalability.
Refer to the documentation at <http://oss.sgi.com/projects/xfs/>
for complete details. This implementation is on-disk compatible
with the IRIX version of XFS.
To compile this file system support as a module, choose M here: the
module will be called xfs. Be aware, however, that if the file
system of your root partition is compiled as a module, you'll need
to use an initial ramdisk (initrd) to boot.
config XFS_SUPPORT_V4
bool "Support deprecated V4 (crc=0) format"
depends on XFS_FS
default y
help
The V4 filesystem format lacks certain features that are supported
by the V5 format, such as metadata checksumming, strengthened
metadata verification, and the ability to store timestamps past the
year 2038. Because of this, the V4 format is deprecated. All users
should upgrade by backing up their files, reformatting, and restoring
from the backup.
Administrators and users can detect a V4 filesystem by running
xfs_info against a filesystem mountpoint and checking for a string
beginning with "crc=". If the string "crc=0" is found, the
filesystem is a V4 filesystem. If no such string is found, please
upgrade xfsprogs to the latest version and try again.
This option will become default N in September 2025. Support for the
V4 format will be removed entirely in September 2030. Distributors
can say N here to withdraw support earlier.
To continue supporting the old V4 format (crc=0), say Y.
To close off an attack surface, say N.
config XFS_SUPPORT_ASCII_CI
bool "Support deprecated case-insensitive ascii (ascii-ci=1) format"
depends on XFS_FS
default y
help
The ASCII case insensitivity filesystem feature only works correctly
on systems that have been coerced into using ISO 8859-1, and it does
not work on extended attributes. The kernel has no visibility into
the locale settings in userspace, so it corrupts UTF-8 names.
Enabling this feature makes XFS vulnerable to mixed case sensitivity
attacks. Because of this, the feature is deprecated. All users
should upgrade by backing up their files, reformatting, and restoring
from the backup.
Administrators and users can detect such a filesystem by running
xfs_info against a filesystem mountpoint and checking for a string
beginning with "ascii-ci=". If the string "ascii-ci=1" is found, the
filesystem is a case-insensitive filesystem. If no such string is
found, please upgrade xfsprogs to the latest version and try again.
This option will become default N in September 2025. Support for the
feature will be removed entirely in September 2030. Distributors
can say N here to withdraw support earlier.
To continue supporting case-insensitivity (ascii-ci=1), say Y.
To close off an attack surface, say N.
config XFS_QUOTA
bool "XFS Quota support"
depends on XFS_FS
select QUOTACTL
help
If you say Y here, you will be able to set limits for disk usage on
a per user and/or a per group basis under XFS. XFS considers quota
information as filesystem metadata and uses journaling to provide a
higher level guarantee of consistency. The on-disk data format for
quota is also compatible with the IRIX version of XFS, allowing a
filesystem to be migrated between Linux and IRIX without any need
for conversion.
If unsure, say N. More comprehensive documentation can be found in
README.quota in the xfsprogs package. XFS quota can be used either
with or without the generic quota support enabled (CONFIG_QUOTA) -
they are completely independent subsystems.
config XFS_POSIX_ACL
bool "XFS POSIX ACL support"
depends on XFS_FS
select FS_POSIX_ACL
help
POSIX Access Control Lists (ACLs) support permissions for users and
groups beyond the owner/group/world scheme.
If you don't know what Access Control Lists are, say N.
config XFS_RT
bool "XFS Realtime subvolume support"
depends on XFS_FS
help
If you say Y here you will be able to mount and use XFS filesystems
which contain a realtime subvolume. The realtime subvolume is a
separate area of disk space where only file data is stored. It was
originally designed to provide deterministic data rates suitable
for media streaming applications, but is also useful as a generic
mechanism for ensuring data and metadata/log I/Os are completely
separated. Regular file I/Os are isolated to a separate device
from all other requests, and this can be done quite transparently
to applications via the inherit-realtime directory inode flag.
See the xfs man page in section 5 for additional information.
If unsure, say N.
xfs: allow queued AG intents to drain before scrubbing When a writer thread executes a chain of log intent items, the AG header buffer locks will cycle during a transaction roll to get from one intent item to the next in a chain. Although scrub takes all AG header buffer locks, this isn't sufficient to guard against scrub checking an AG while that writer thread is in the middle of finishing a chain because there's no higher level locking primitive guarding allocation groups. When there's a collision, cross-referencing between data structures (e.g. rmapbt and refcountbt) yields false corruption events; if repair is running, this results in incorrect repairs, which is catastrophic. Fix this by adding to the perag structure the count of active intents and make scrub wait until it has both AG header buffer locks and the intent counter reaches zero. One quirk of the drain code is that deferred bmap updates also bump and drop the intent counter. A fundamental decision made during the design phase of the reverse mapping feature is that updates to the rmapbt records are always made by the same code that updates the primary metadata. In other words, callers of bmapi functions expect that the bmapi functions will queue deferred rmap updates. Some parts of the reflink code queue deferred refcount (CUI) and bmap (BUI) updates in the same head transaction, but the deferred work manager completely finishes the CUI before the BUI work is started. As a result, the CUI drops the intent count long before the deferred rmap (RUI) update even has a chance to bump the intent count. The only way to keep the intent count elevated between the CUI and RUI is for the BUI to bump the counter until the RUI has been created. A second quirk of the intent drain code is that deferred work items must increment the intent counter as soon as the work item is added to the transaction. When a BUI completes and queues an RUI, the RUI must increment the counter before the BUI decrements it. The only way to accomplish this is to require that the counter be bumped as soon as the deferred work item is created in memory. In the next patches we'll improve on this facility, but this patch provides the basic functionality. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-12 09:59:58 +08:00
config XFS_DRAIN_INTENTS
bool
select JUMP_LABEL if HAVE_ARCH_JUMP_LABEL
xfs: allow queued AG intents to drain before scrubbing When a writer thread executes a chain of log intent items, the AG header buffer locks will cycle during a transaction roll to get from one intent item to the next in a chain. Although scrub takes all AG header buffer locks, this isn't sufficient to guard against scrub checking an AG while that writer thread is in the middle of finishing a chain because there's no higher level locking primitive guarding allocation groups. When there's a collision, cross-referencing between data structures (e.g. rmapbt and refcountbt) yields false corruption events; if repair is running, this results in incorrect repairs, which is catastrophic. Fix this by adding to the perag structure the count of active intents and make scrub wait until it has both AG header buffer locks and the intent counter reaches zero. One quirk of the drain code is that deferred bmap updates also bump and drop the intent counter. A fundamental decision made during the design phase of the reverse mapping feature is that updates to the rmapbt records are always made by the same code that updates the primary metadata. In other words, callers of bmapi functions expect that the bmapi functions will queue deferred rmap updates. Some parts of the reflink code queue deferred refcount (CUI) and bmap (BUI) updates in the same head transaction, but the deferred work manager completely finishes the CUI before the BUI work is started. As a result, the CUI drops the intent count long before the deferred rmap (RUI) update even has a chance to bump the intent count. The only way to keep the intent count elevated between the CUI and RUI is for the BUI to bump the counter until the RUI has been created. A second quirk of the intent drain code is that deferred work items must increment the intent counter as soon as the work item is added to the transaction. When a BUI completes and queues an RUI, the RUI must increment the counter before the BUI decrements it. The only way to accomplish this is to require that the counter be bumped as soon as the deferred work item is created in memory. In the next patches we'll improve on this facility, but this patch provides the basic functionality. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-12 09:59:58 +08:00
config XFS_ONLINE_SCRUB
bool "XFS online metadata check support"
default n
depends on XFS_FS
depends on TMPFS && SHMEM
xfs: allow queued AG intents to drain before scrubbing When a writer thread executes a chain of log intent items, the AG header buffer locks will cycle during a transaction roll to get from one intent item to the next in a chain. Although scrub takes all AG header buffer locks, this isn't sufficient to guard against scrub checking an AG while that writer thread is in the middle of finishing a chain because there's no higher level locking primitive guarding allocation groups. When there's a collision, cross-referencing between data structures (e.g. rmapbt and refcountbt) yields false corruption events; if repair is running, this results in incorrect repairs, which is catastrophic. Fix this by adding to the perag structure the count of active intents and make scrub wait until it has both AG header buffer locks and the intent counter reaches zero. One quirk of the drain code is that deferred bmap updates also bump and drop the intent counter. A fundamental decision made during the design phase of the reverse mapping feature is that updates to the rmapbt records are always made by the same code that updates the primary metadata. In other words, callers of bmapi functions expect that the bmapi functions will queue deferred rmap updates. Some parts of the reflink code queue deferred refcount (CUI) and bmap (BUI) updates in the same head transaction, but the deferred work manager completely finishes the CUI before the BUI work is started. As a result, the CUI drops the intent count long before the deferred rmap (RUI) update even has a chance to bump the intent count. The only way to keep the intent count elevated between the CUI and RUI is for the BUI to bump the counter until the RUI has been created. A second quirk of the intent drain code is that deferred work items must increment the intent counter as soon as the work item is added to the transaction. When a BUI completes and queues an RUI, the RUI must increment the counter before the BUI decrements it. The only way to accomplish this is to require that the counter be bumped as soon as the deferred work item is created in memory. In the next patches we'll improve on this facility, but this patch provides the basic functionality. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-12 09:59:58 +08:00
select XFS_DRAIN_INTENTS
help
If you say Y here you will be able to check metadata on a
mounted XFS filesystem. This feature is intended to reduce
filesystem downtime by supplementing xfs_repair. The key
advantage here is to look for problems proactively so that
they can be dealt with in a controlled manner.
This feature is considered EXPERIMENTAL. Use with caution!
See the xfs_scrub man page in section 8 for additional information.
If unsure, say N.
config XFS_ONLINE_SCRUB_STATS
bool "XFS online metadata check usage data collection"
default y
depends on XFS_ONLINE_SCRUB
select DEBUG_FS
help
If you say Y here, the kernel will gather usage data about
the online metadata check subsystem. This includes the number
of invocations, the outcomes, and the results of repairs, if any.
This may slow down scrub slightly due to the use of high precision
timers and the need to merge per-invocation information into the
filesystem counters.
Usage data are collected in /sys/kernel/debug/xfs/scrub.
If unsure, say N.
config XFS_ONLINE_REPAIR
bool "XFS online metadata repair support"
default n
depends on XFS_FS && XFS_ONLINE_SCRUB
help
If you say Y here you will be able to repair metadata on a
mounted XFS filesystem. This feature is intended to reduce
filesystem downtime by fixing minor problems before they cause the
filesystem to go down. However, it requires that the filesystem be
formatted with secondary metadata, such as reverse mappings and inode
parent pointers.
This feature is considered EXPERIMENTAL. Use with caution!
See the xfs_scrub man page in section 8 for additional information.
If unsure, say N.
config XFS_WARN
bool "XFS Verbose Warnings"
depends on XFS_FS && !XFS_DEBUG
help
Say Y here to get an XFS build with many additional warnings.
It converts ASSERT checks to WARN, so will log any out-of-bounds
conditions that occur that would otherwise be missed. It is much
lighter weight than XFS_DEBUG and does not modify algorithms and will
not cause the kernel to panic on non-fatal errors.
However, similar to XFS_DEBUG, it is only advisable to use this if you
are debugging a particular problem.
config XFS_DEBUG
bool "XFS Debugging support"
depends on XFS_FS
help
Say Y here to get an XFS build with many debugging features,
including ASSERT checks, function wrappers around macros,
and extra sanity-checking functions in various code paths.
Note that the resulting code will be HUGE and SLOW, and probably
not useful unless you are debugging a particular problem.
Say N unless you are an XFS developer, or you play one on TV.
config XFS_ASSERT_FATAL
bool "XFS fatal asserts"
default y
depends on XFS_FS && XFS_DEBUG
help
Set the default DEBUG mode ASSERT failure behavior.
Say Y here to cause DEBUG mode ASSERT failures to result in fatal
errors that BUG() the kernel by default. If you say N, ASSERT failures
result in warnings.
This behavior can be modified at runtime via sysfs.