# SPDX-License-Identifier: GPL-2.0-only # # File system configuration # menu "File systems" # Use unaligned word dcache accesses config DCACHE_WORD_ACCESS bool config VALIDATE_FS_PARSER bool "Validate filesystem parameter description" help Enable this to perform validation of the parameter description for a filesystem when it is registered. config FS_IOMAP bool config BUFFER_HEAD bool # old blockdev_direct_IO implementation. Use iomap for new code instead config LEGACY_DIRECT_IO depends on BUFFER_HEAD bool if BLOCK source "fs/ext2/Kconfig" source "fs/ext4/Kconfig" source "fs/jbd2/Kconfig" config FS_MBCACHE # Meta block cache for Extended Attributes (ext2/ext3/ext4) tristate default y if EXT2_FS=y && EXT2_FS_XATTR default y if EXT4_FS=y default m if EXT2_FS_XATTR || EXT4_FS source "fs/reiserfs/Kconfig" source "fs/jfs/Kconfig" source "fs/xfs/Kconfig" source "fs/gfs2/Kconfig" source "fs/ocfs2/Kconfig" source "fs/btrfs/Kconfig" source "fs/nilfs2/Kconfig" source "fs/f2fs/Kconfig" source "fs/zonefs/Kconfig" endif # BLOCK config FS_DAX bool "File system based Direct Access (DAX) support" depends on MMU depends on !(ARM || MIPS || SPARC) depends on ZONE_DEVICE || FS_DAX_LIMITED select FS_IOMAP select DAX help Direct Access (DAX) can be used on memory-backed block devices. If the block device supports DAX and the filesystem supports DAX, then you can avoid using the pagecache to buffer I/Os. Turning on this option will compile in support for DAX. For a DAX device to support file system access it needs to have struct pages. For the nfit based NVDIMMs this can be enabled using the ndctl utility: # ndctl create-namespace --force --reconfig=namespace0.0 \ --mode=fsdax --map=mem See the 'create-namespace' man page for details on the overhead of --map=mem: https://docs.pmem.io/ndctl-user-guide/ndctl-man-pages/ndctl-create-namespace For ndctl to work CONFIG_DEV_DAX needs to be enabled as well. For most file systems DAX support needs to be manually enabled globally or per-inode using a mount option as well. See the file documentation in Documentation/filesystems/dax.rst for details. If you do not have a block device that is capable of using this, or if unsure, say N. Saying Y will increase the size of the kernel by about 5kB. config FS_DAX_PMD bool default FS_DAX depends on FS_DAX depends on ZONE_DEVICE depends on TRANSPARENT_HUGEPAGE # Selected by DAX drivers that do not expect filesystem DAX to support # get_user_pages() of DAX mappings. I.e. "limited" indicates no support # for fork() of processes with MAP_SHARED mappings or support for # direct-I/O to a DAX mapping. config FS_DAX_LIMITED bool # Posix ACL utility routines # # Note: Posix ACLs can be implemented without these helpers. Never use # this symbol for ifdefs in core code. # config FS_POSIX_ACL def_bool n config EXPORTFS tristate config EXPORTFS_BLOCK_OPS bool "Enable filesystem export operations for block IO" help This option enables the export operations for a filesystem to support external block IO. config FILE_LOCKING bool "Enable POSIX file locking API" if EXPERT default y help This option enables standard file locking support, required for filesystems like NFS and for the flock() system call. Disabling this option saves about 11k. source "fs/crypto/Kconfig" source "fs/verity/Kconfig" source "fs/notify/Kconfig" source "fs/quota/Kconfig" source "fs/autofs/Kconfig" source "fs/fuse/Kconfig" source "fs/overlayfs/Kconfig" source "fs/incfs/Kconfig" menu "Caches" source "fs/netfs/Kconfig" source "fs/fscache/Kconfig" source "fs/cachefiles/Kconfig" endmenu if BLOCK menu "CD-ROM/DVD Filesystems" source "fs/isofs/Kconfig" source "fs/udf/Kconfig" endmenu endif # BLOCK if BLOCK menu "DOS/FAT/EXFAT/NT Filesystems" source "fs/fat/Kconfig" source "fs/exfat/Kconfig" source "fs/ntfs/Kconfig" source "fs/ntfs3/Kconfig" endmenu endif # BLOCK menu "Pseudo filesystems" source "fs/proc/Kconfig" source "fs/kernfs/Kconfig" source "fs/sysfs/Kconfig" config TMPFS bool "Tmpfs virtual memory file system support (former shm fs)" depends on SHMEM select MEMFD_CREATE help Tmpfs is a file system which keeps all files in virtual memory. Everything in tmpfs is temporary in the sense that no files will be created on your hard drive. The files live in memory and swap space. If you unmount a tmpfs instance, everything stored therein is lost. See for details. config TMPFS_POSIX_ACL bool "Tmpfs POSIX Access Control Lists" depends on TMPFS select TMPFS_XATTR select FS_POSIX_ACL help POSIX Access Control Lists (ACLs) support additional access rights for users and groups beyond the standard owner/group/world scheme, and this option selects support for ACLs specifically for tmpfs filesystems. If you've selected TMPFS, it's possible that you'll also need this option as there are a number of Linux distros that require POSIX ACL support under /dev for certain features to work properly. For example, some distros need this feature for ALSA-related /dev files for sound to work properly. In short, if you're not sure, say Y. config TMPFS_XATTR bool "Tmpfs extended attributes" depends on TMPFS default n help Extended attributes are name:value pairs associated with inodes by the kernel or by users (see the attr(5) manual page for details). This enables support for the trusted.*, security.* and user.* namespaces. You need this for POSIX ACL support on tmpfs. If unsure, say N. config TMPFS_INODE64 bool "Use 64-bit ino_t by default in tmpfs" depends on TMPFS && 64BIT default n help tmpfs has historically used only inode numbers as wide as an unsigned int. In some cases this can cause wraparound, potentially resulting in multiple files with the same inode number on a single device. This option makes tmpfs use the full width of ino_t by default, without needing to specify the inode64 option when mounting. But if a long-lived tmpfs is to be accessed by 32-bit applications so ancient that opening a file larger than 2GiB fails with EINVAL, then the INODE64 config option and inode64 mount option risk operations failing with EOVERFLOW once 33-bit inode numbers are reached. To override this configured default, use the inode32 or inode64 option when mounting. If unsure, say N. config TMPFS_QUOTA bool "Tmpfs quota support" depends on TMPFS select QUOTA help Quota support allows to set per user and group limits for tmpfs usage. Say Y to enable quota support. Once enabled you can control user and group quota enforcement with quota, usrquota and grpquota mount options. If unsure, say N. config ARCH_SUPPORTS_HUGETLBFS def_bool n config HUGETLBFS bool "HugeTLB file system support" depends on X86 || IA64 || SPARC64 || ARCH_SUPPORTS_HUGETLBFS || BROKEN depends on (SYSFS || SYSCTL) select MEMFD_CREATE help hugetlbfs is a filesystem backing for HugeTLB pages, based on ramfs. For architectures that support it, say Y here and read for details. If unsure, say N. config HUGETLB_PAGE def_bool HUGETLBFS config HUGETLB_PAGE_OPTIMIZE_VMEMMAP def_bool HUGETLB_PAGE depends on ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP depends on SPARSEMEM_VMEMMAP config HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON bool "HugeTLB Vmemmap Optimization (HVO) defaults to on" default n depends on HUGETLB_PAGE_OPTIMIZE_VMEMMAP help The HugeTLB VmemmapvOptimization (HVO) defaults to off. Say Y here to enable HVO by default. It can be disabled via hugetlb_free_vmemmap=off (boot command line) or hugetlb_optimize_vmemmap (sysctl). config ARCH_HAS_GIGANTIC_PAGE bool source "fs/configfs/Kconfig" source "fs/efivarfs/Kconfig" endmenu menuconfig MISC_FILESYSTEMS bool "Miscellaneous filesystems" default y help Say Y here to get to see options for various miscellaneous filesystems, such as filesystems that came from other operating systems. This option alone does not add any kernel code. If you say N, all options in this submenu will be skipped and disabled; if unsure, say Y here. if MISC_FILESYSTEMS source "fs/orangefs/Kconfig" source "fs/adfs/Kconfig" source "fs/affs/Kconfig" source "fs/ecryptfs/Kconfig" source "fs/hfs/Kconfig" source "fs/hfsplus/Kconfig" source "fs/befs/Kconfig" source "fs/bfs/Kconfig" source "fs/efs/Kconfig" source "fs/jffs2/Kconfig" # UBIFS File system configuration source "fs/ubifs/Kconfig" source "fs/cramfs/Kconfig" source "fs/squashfs/Kconfig" source "fs/freevxfs/Kconfig" source "fs/minix/Kconfig" source "fs/omfs/Kconfig" source "fs/hpfs/Kconfig" source "fs/qnx4/Kconfig" source "fs/qnx6/Kconfig" source "fs/romfs/Kconfig" source "fs/pstore/Kconfig" source "fs/sysv/Kconfig" source "fs/ufs/Kconfig" source "fs/erofs/Kconfig" source "fs/vboxsf/Kconfig" endif # MISC_FILESYSTEMS menuconfig NETWORK_FILESYSTEMS bool "Network File Systems" default y depends on NET help Say Y here to get to see options for network filesystems and filesystem-related networking code, such as NFS daemon and RPCSEC security modules. This option alone does not add any kernel code. If you say N, all options in this submenu will be skipped and disabled; if unsure, say Y here. if NETWORK_FILESYSTEMS source "fs/nfs/Kconfig" source "fs/nfsd/Kconfig" config GRACE_PERIOD tristate config LOCKD tristate depends on FILE_LOCKING select GRACE_PERIOD config LOCKD_V4 bool depends on NFSD || NFS_V3 depends on FILE_LOCKING default y config NFS_ACL_SUPPORT tristate select FS_POSIX_ACL config NFS_COMMON bool depends on NFSD || NFS_FS || LOCKD default y config NFS_V4_2_SSC_HELPER bool default y if NFS_V4_2 source "net/sunrpc/Kconfig" source "fs/ceph/Kconfig" source "fs/smb/Kconfig" source "fs/coda/Kconfig" source "fs/afs/Kconfig" source "fs/9p/Kconfig" endif # NETWORK_FILESYSTEMS source "fs/nls/Kconfig" source "fs/dlm/Kconfig" source "fs/unicode/Kconfig" config IO_WQ bool endmenu