fs/aufs/Kconfig

   1 config AUFS_FS
   2         tristate "Aufs (Advanced multi layered unification filesystem) support"
   3         help
   4         Aufs is a stackable unification filesystem such as Unionfs,
   5         which unifies several directories and provides a merged single
   6         directory.
   7         In the early days, aufs was entirely re-designed and
   8         re-implemented Unionfs Version 1.x series. Introducing many
   9         original ideas, approaches and improvements, it becomes totally
  10         different from Unionfs while keeping the basic features.
  11
  12 if AUFS_FS
  13 choice
  14         prompt "Maximum number of branches"
  15         default AUFS_BRANCH_MAX_127
  16         help
  17         Specifies the maximum number of branches (or member directories)
  18         in a single aufs. The larger value consumes more system
  19         resources and has a minor impact to performance.
  20 config AUFS_BRANCH_MAX_127
  21         bool "127"
  22         help
  23         Specifies the maximum number of branches (or member directories)
  24         in a single aufs. The larger value consumes more system
  25         resources and has a minor impact to performance.
  26 config AUFS_BRANCH_MAX_511
  27         bool "511"
  28         help
  29         Specifies the maximum number of branches (or member directories)
  30         in a single aufs. The larger value consumes more system
  31         resources and has a minor impact to performance.
  32 config AUFS_BRANCH_MAX_1023
  33         bool "1023"
  34         help
  35         Specifies the maximum number of branches (or member directories)
  36         in a single aufs. The larger value consumes more system
  37         resources and has a minor impact to performance.
  38 config AUFS_BRANCH_MAX_32767
  39         bool "32767"
  40         help
  41         Specifies the maximum number of branches (or member directories)
  42         in a single aufs. The larger value consumes more system
  43         resources and has a minor impact to performance.
  44 endchoice
  45
  46 config AUFS_SBILIST
  47         bool
  48         depends on AUFS_MAGIC_SYSRQ || PROC_FS
  49         default y
  50         help
  51         Automatic configuration for internal use.
  52         When aufs supports Magic SysRq or /proc, enabled automatically.
  53
  54 config AUFS_HNOTIFY
  55         bool "Detect direct branch access (bypassing aufs)"
  56         help
  57         If you want to modify files on branches directly, eg. bypassing aufs,
  58         and want aufs to detect the changes of them fully, then enable this
  59         option and use 'udba=notify' mount option.
  60         Currently there is only one available configuration, "fsnotify".
  61         It will have a negative impact to the performance.
  62         See detail in aufs.5.
  63
  64 choice
  65         prompt "method" if AUFS_HNOTIFY
  66         default AUFS_HFSNOTIFY
  67 config AUFS_HFSNOTIFY
  68         bool "fsnotify"
  69         select FSNOTIFY
  70 endchoice
  71
  72 config AUFS_EXPORT
  73         bool "NFS-exportable aufs"
  74         depends on EXPORTFS
  75         help
  76         If you want to export your mounted aufs via NFS, then enable this
  77         option. There are several requirements for this configuration.
  78         See detail in aufs.5.
  79
  80 config AUFS_INO_T_64
  81         bool
  82         depends on AUFS_EXPORT
  83         depends on 64BIT && !(ALPHA || S390)
  84         default y
  85         help
  86         Automatic configuration for internal use.
  87         /* typedef unsigned long/int __kernel_ino_t */
  88         /* alpha and s390x are int */
  89
  90 config AUFS_XATTR
  91         bool "support for XATTR/EA (including Security Labels)"
  92         help
  93         If your branch fs supports XATTR/EA and you want to make them
  94         available in aufs too, then enable this opsion and specify the
  95         branch attributes for EA.
  96         See detail in aufs.5.
  97
  98 config AUFS_FHSM
  99         bool "File-based Hierarchical Storage Management"
 100         help
 101         Hierarchical Storage Management (or HSM) is a well-known feature
 102         in the storage world. Aufs provides this feature as file-based.
 103         with multiple branches.
 104         These multiple branches are prioritized, ie. the topmost one
 105         should be the fastest drive and be used heavily.
 106
 107 config AUFS_RDU
 108         bool "Readdir in userspace"
 109         help
 110         Aufs has two methods to provide a merged view for a directory,
 111         by a user-space library and by kernel-space natively. The latter
 112         is always enabled but sometimes large and slow.
 113         If you enable this option, install the library in aufs2-util
 114         package, and set some environment variables for your readdir(3),
 115         then the work will be handled in user-space which generally
 116         shows better performance in most cases.
 117         See detail in aufs.5.
 118
 119 config AUFS_SHWH
 120         bool "Show whiteouts"
 121         help
 122         If you want to make the whiteouts in aufs visible, then enable
 123         this option and specify 'shwh' mount option. Although it may
 124         sounds like philosophy or something, but in technically it
 125         simply shows the name of whiteout with keeping its behaviour.
 126
 127 config AUFS_BR_RAMFS
 128         bool "Ramfs (initramfs/rootfs) as an aufs branch"
 129         help
 130         If you want to use ramfs as an aufs branch fs, then enable this
 131         option. Generally tmpfs is recommended.
 132         Aufs prohibited them to be a branch fs by default, because
 133         initramfs becomes unusable after switch_root or something
 134         generally. If you sets initramfs as an aufs branch and boot your
 135         system by switch_root, you will meet a problem easily since the
 136         files in initramfs may be inaccessible.
 137         Unless you are going to use ramfs as an aufs branch fs without
 138         switch_root or something, leave it N.
 139
 140 config AUFS_BR_FUSE
 141         bool "Fuse fs as an aufs branch"
 142         depends on FUSE_FS
 143         select AUFS_POLL
 144         help
 145         If you want to use fuse-based userspace filesystem as an aufs
 146         branch fs, then enable this option.
 147         It implements the internal poll(2) operation which is
 148         implemented by fuse only (curretnly).
 149
 150 config AUFS_POLL
 151         bool
 152         help
 153         Automatic configuration for internal use.
 154
 155 config AUFS_BR_HFSPLUS
 156         bool "Hfsplus as an aufs branch"
 157         depends on HFSPLUS_FS
 158         default y
 159         help
 160         If you want to use hfsplus fs as an aufs branch fs, then enable
 161         this option. This option introduces a small overhead at
 162         copying-up a file on hfsplus.
 163
 164 config AUFS_BDEV_LOOP
 165         bool
 166         depends on BLK_DEV_LOOP
 167         default y
 168         help
 169         Automatic configuration for internal use.
 170         Convert =[ym] into =y.
 171
 172 config AUFS_DEBUG
 173         bool "Debug aufs"
 174         help
 175         Enable this to compile aufs internal debug code.
 176         It will have a negative impact to the performance.
 177
 178 config AUFS_MAGIC_SYSRQ
 179         bool
 180         depends on AUFS_DEBUG && MAGIC_SYSRQ
 181         default y
 182         help
 183         Automatic configuration for internal use.
 184         When aufs supports Magic SysRq, enabled automatically.
 185 endif