2 tristate "Aufs (Advanced multi layered unification filesystem) support"
4 Aufs is a stackable unification filesystem such as Unionfs,
5 which unifies several directories and provides a merged single
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.
14 prompt "Maximum number of branches"
15 default AUFS_BRANCH_MAX_127
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
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
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
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
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.
48 depends on AUFS_MAGIC_SYSRQ || PROC_FS
51 Automatic configuration for internal use.
52 When aufs supports Magic SysRq or /proc, enabled automatically.
55 bool "Detect direct branch access (bypassing aufs)"
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.
65 prompt "method" if AUFS_HNOTIFY
66 default AUFS_HFSNOTIFY
73 bool "NFS-exportable aufs"
76 If you want to export your mounted aufs via NFS, then enable this
77 option. There are several requirements for this configuration.
82 depends on AUFS_EXPORT
83 depends on 64BIT && !(ALPHA || S390)
86 Automatic configuration for internal use.
87 /* typedef unsigned long/int __kernel_ino_t */
88 /* alpha and s390x are int */
91 bool "support for XATTR/EA (including Security Labels)"
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.
99 bool "File-based Hierarchical Storage Management"
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.
108 bool "Readdir in userspace"
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.
120 bool "Show whiteouts"
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.
128 bool "Ramfs (initramfs/rootfs) as an aufs branch"
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.
141 bool "Fuse fs as an aufs branch"
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).
153 Automatic configuration for internal use.
155 config AUFS_BR_HFSPLUS
156 bool "Hfsplus as an aufs branch"
157 depends on HFSPLUS_FS
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.
164 config AUFS_BDEV_LOOP
166 depends on BLK_DEV_LOOP
169 Automatic configuration for internal use.
170 Convert =[ym] into =y.
175 Enable this to compile aufs internal debug code.
176 It will have a negative impact to the performance.
178 config AUFS_MAGIC_SYSRQ
180 depends on AUFS_DEBUG && MAGIC_SYSRQ
183 Automatic configuration for internal use.
184 When aufs supports Magic SysRq, enabled automatically.