Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1# SPDX-License-Identifier: GPL-2.0
2#
3# Block device driver configuration
4#
5
6menuconfig BLK_DEV
7 bool "Block devices"
8 depends on BLOCK
9 default y
10 help
11 Say Y here to get to see options for various different block device
12 drivers. This option alone does not add any kernel code.
13
14 If you say N, all options in this submenu will be skipped and disabled;
15 only do this if you know what you are doing.
16
17if BLK_DEV
18
19source "drivers/block/null_blk/Kconfig"
20source "drivers/block/rnull/Kconfig"
21
22config BLK_DEV_FD
23 tristate "Normal floppy disk support"
24 depends on ARCH_MAY_HAVE_PC_FDC
25 help
26 If you want to use the floppy disk drive(s) of your PC under Linux,
27 say Y. Information about this driver, especially important for IBM
28 Thinkpad users, is contained in
29 <file:Documentation/admin-guide/blockdev/floppy.rst>.
30 That file also contains the location of the Floppy driver FAQ as
31 well as location of the fdutils package used to configure additional
32 parameters of the driver at run time.
33
34 To compile this driver as a module, choose M here: the
35 module will be called floppy.
36
37config BLK_DEV_FD_RAWCMD
38 bool "Support for raw floppy disk commands (DEPRECATED)"
39 depends on BLK_DEV_FD
40 help
41 If you want to use actual physical floppies and expect to do
42 special low-level hardware accesses to them (access and use
43 non-standard formats, for example), then enable this.
44
45 Note that the code enabled by this option is rarely used and
46 might be unstable or insecure, and distros should not enable it.
47
48 Note: FDRAWCMD is deprecated and will be removed from the kernel
49 in the near future.
50
51 If unsure, say N.
52
53config AMIGA_FLOPPY
54 tristate "Amiga floppy support"
55 depends on AMIGA
56
57config ATARI_FLOPPY
58 tristate "Atari floppy support"
59 depends on ATARI
60
61config MAC_FLOPPY
62 tristate "Support for PowerMac floppy"
63 depends on PPC_PMAC && !PPC_PMAC64
64 help
65 If you have a SWIM-3 (Super Woz Integrated Machine 3; from Apple)
66 floppy controller, say Y here. Most commonly found in PowerMacs.
67
68config BLK_DEV_SWIM
69 tristate "Support for SWIM Macintosh floppy"
70 depends on M68K && MAC && !HIGHMEM
71 help
72 You should select this option if you want floppy support
73 and you don't have a II, IIfx, Q900, Q950 or AV series.
74
75config AMIGA_Z2RAM
76 tristate "Amiga Zorro II ramdisk support"
77 depends on ZORRO
78 help
79 This enables support for using Chip RAM and Zorro II RAM as a
80 ramdisk or as a swap partition. Say Y if you want to include this
81 driver in the kernel.
82
83 To compile this driver as a module, choose M here: the
84 module will be called z2ram.
85
86config N64CART
87 bool "N64 cart support"
88 depends on MACH_NINTENDO64
89 help
90 Support for the N64 cart.
91
92config CDROM
93 tristate
94
95config GDROM
96 tristate "SEGA Dreamcast GD-ROM drive"
97 depends on SH_DREAMCAST
98 select CDROM
99 help
100 A standard SEGA Dreamcast comes with a modified CD ROM drive called a
101 "GD-ROM" by SEGA to signify it is capable of reading special disks
102 with up to 1 GB of data. This drive will also read standard CD ROM
103 disks. Select this option to access any disks in your GD ROM drive.
104 Most users will want to say "Y" here.
105 You can also build this as a module which will be called gdrom.
106
107source "drivers/block/mtip32xx/Kconfig"
108
109source "drivers/block/zram/Kconfig"
110
111config BLK_DEV_UBD
112 bool "Virtual block device"
113 depends on UML
114 help
115 The User-Mode Linux port includes a driver called UBD which will let
116 you access arbitrary files on the host computer as block devices.
117 Unless you know that you do not need such virtual block devices say
118 Y here.
119
120config BLK_DEV_UBD_SYNC
121 bool "Always do synchronous disk IO for UBD"
122 depends on BLK_DEV_UBD
123 help
124 Writes to the virtual block device are not immediately written to the
125 host's disk; this may cause problems if, for example, the User-Mode
126 Linux 'Virtual Machine' uses a journalling filesystem and the host
127 computer crashes.
128
129 Synchronous operation (i.e. always writing data to the host's disk
130 immediately) is configurable on a per-UBD basis by using a special
131 kernel command line option. Alternatively, you can say Y here to
132 turn on synchronous operation by default for all block devices.
133
134 If you're running a journalling file system (like xfs, for
135 example) in your virtual machine, you will want to say Y here. If
136 you care for the safety of the data in your virtual machine, Y is a
137 wise choice too. In all other cases (for example, if you're just
138 playing around with User-Mode Linux) you can choose N.
139
140config BLK_DEV_COW_COMMON
141 bool
142 default BLK_DEV_UBD
143
144config BLK_DEV_LOOP
145 tristate "Loopback device support"
146 help
147 Saying Y here will allow you to use a regular file as a block
148 device; you can then create a file system on that block device and
149 mount it just as you would mount other block devices such as hard
150 drive partitions, CD-ROM drives or floppy drives. The loop devices
151 are block special device files with major number 7 and typically
152 called /dev/loop0, /dev/loop1 etc.
153
154 This is useful if you want to check an ISO 9660 file system before
155 burning the CD, or if you want to use floppy images without first
156 writing them to floppy. Furthermore, some Linux distributions avoid
157 the need for a dedicated Linux partition by keeping their complete
158 root file system inside a DOS FAT file using this loop device
159 driver.
160
161 To use the loop device, you need the losetup utility, found in the
162 util-linux package, see
163 <https://www.kernel.org/pub/linux/utils/util-linux/>.
164
165 The loop device driver can also be used to "hide" a file system in
166 a disk partition, floppy, or regular file, either using encryption
167 (scrambling the data) or steganography (hiding the data in the low
168 bits of, say, a sound file). This is also safe if the file resides
169 on a remote file server.
170
171 Note that this loop device has nothing to do with the loopback
172 device used for network connections from the machine to itself.
173
174 To compile this driver as a module, choose M here: the
175 module will be called loop.
176
177 Most users will answer N here.
178
179config BLK_DEV_LOOP_MIN_COUNT
180 int "Number of loop devices to pre-create at init time"
181 depends on BLK_DEV_LOOP
182 default 8
183 help
184 Static number of loop devices to be unconditionally pre-created
185 at init time.
186
187 This default value can be overwritten on the kernel command
188 line or with module-parameter loop.max_loop.
189
190 The historic default is 8. If a late 2011 version of losetup(8)
191 is used, it can be set to 0, since needed loop devices can be
192 dynamically allocated with the /dev/loop-control interface.
193
194source "drivers/block/drbd/Kconfig"
195
196config BLK_DEV_NBD
197 tristate "Network block device support"
198 depends on NET
199 help
200 Saying Y here will allow your computer to be a client for network
201 block devices, i.e. it will be able to use block devices exported by
202 servers (mount file systems on them etc.). Communication between
203 client and server works over TCP/IP networking, but to the client
204 program this is hidden: it looks like a regular local file access to
205 a block device special file such as /dev/nd0.
206
207 Network block devices also allows you to run a block-device in
208 userland (making server and client physically the same computer,
209 communicating using the loopback network device).
210
211 Read <file:Documentation/admin-guide/blockdev/nbd.rst> for more information,
212 especially about where to find the server code, which runs in user
213 space and does not need special kernel support.
214
215 Note that this has nothing to do with the network file systems NFS
216 or Coda; you can say N here even if you intend to use NFS or Coda.
217
218 To compile this driver as a module, choose M here: the
219 module will be called nbd.
220
221 If unsure, say N.
222
223config BLK_DEV_RAM
224 tristate "RAM block device support"
225 help
226 Saying Y here will allow you to use a portion of your RAM memory as
227 a block device, so that you can make file systems on it, read and
228 write to it and do all the other things that you can do with normal
229 block devices (such as hard drives). It is usually used to load and
230 store a copy of a minimal root file system off of a floppy into RAM
231 during the initial install of Linux.
232
233 Note that the kernel command line option "ramdisk=XX" is now obsolete.
234 For details, read <file:Documentation/admin-guide/blockdev/ramdisk.rst>.
235
236 To compile this driver as a module, choose M here: the
237 module will be called brd. An alias "rd" has been defined
238 for historical reasons.
239
240 Most normal users won't need the RAM disk functionality, and can
241 thus say N here.
242
243config BLK_DEV_RAM_COUNT
244 int "Default number of RAM disks"
245 default "16"
246 depends on BLK_DEV_RAM
247 help
248 The default value is 16 RAM disks. Change this if you know what you
249 are doing. If you boot from a filesystem that needs to be extracted
250 in memory, you will need at least one RAM disk (e.g. root on cramfs).
251
252config BLK_DEV_RAM_SIZE
253 int "Default RAM disk size (kbytes)"
254 depends on BLK_DEV_RAM
255 default "4096"
256 help
257 The default value is 4096 kilobytes. Only change this if you know
258 what you are doing.
259
260config ATA_OVER_ETH
261 tristate "ATA over Ethernet support"
262 depends on NET
263 help
264 This driver provides Support for ATA over Ethernet block
265 devices like the Coraid EtherDrive (R) Storage Blade.
266
267config SUNVDC
268 tristate "Sun Virtual Disk Client support"
269 depends on SUN_LDOMS
270 help
271 Support for virtual disk devices as a client under Sun
272 Logical Domains.
273
274source "drivers/s390/block/Kconfig"
275
276config XEN_BLKDEV_FRONTEND
277 tristate "Xen virtual block device support"
278 depends on XEN
279 default y
280 select XEN_XENBUS_FRONTEND
281 help
282 This driver implements the front-end of the Xen virtual
283 block device driver. It communicates with a back-end driver
284 in another domain which drives the actual block device.
285
286config XEN_BLKDEV_BACKEND
287 tristate "Xen block-device backend driver"
288 depends on XEN_BACKEND
289 help
290 The block-device backend driver allows the kernel to export its
291 block devices to other guests via a high-performance shared-memory
292 interface.
293
294 The corresponding Linux frontend driver is enabled by the
295 CONFIG_XEN_BLKDEV_FRONTEND configuration option.
296
297 The backend driver attaches itself to a any block device specified
298 in the XenBus configuration. There are no limits to what the block
299 device as long as it has a major and minor.
300
301 If you are compiling a kernel to run in a Xen block backend driver
302 domain (often this is domain 0) you should say Y here. To
303 compile this driver as a module, chose M here: the module
304 will be called xen-blkback.
305
306
307config VIRTIO_BLK
308 tristate "Virtio block driver"
309 depends on VIRTIO
310 select SG_POOL
311 help
312 This is the virtual block driver for virtio. It can be used with
313 QEMU based VMMs (like KVM or Xen). Say Y or M.
314
315config BLK_DEV_RBD
316 tristate "Rados block device (RBD)"
317 depends on INET && BLOCK
318 select CEPH_LIB
319 help
320 Say Y here if you want include the Rados block device, which stripes
321 a block device over objects stored in the Ceph distributed object
322 store.
323
324 More information at http://ceph.newdream.net/.
325
326 If unsure, say N.
327
328config BLK_DEV_UBLK
329 tristate "Userspace block driver (Experimental)"
330 select IO_URING
331 help
332 io_uring based userspace block driver. Together with ublk server, ublk
333 has been working well, but interface with userspace or command data
334 definition isn't finalized yet, and might change according to future
335 requirement, so mark is as experimental now.
336
337config BLKDEV_UBLK_LEGACY_OPCODES
338 bool "Support legacy command opcode"
339 depends on BLK_DEV_UBLK
340 default y
341 help
342 ublk driver started to take plain command encoding, which turns out
343 one bad way. The traditional ioctl command opcode encodes more
344 info and basically defines each code uniquely, so opcode conflict
345 is avoided, and driver can handle wrong command easily, meantime it
346 may help security subsystem to audit io_uring command.
347
348 Say Y if your application still uses legacy command opcode.
349
350 Say N if you don't want to support legacy command opcode. It is
351 suggested to enable N if your application(ublk server) switches to
352 ioctl command encoding.
353
354source "drivers/block/rnbd/Kconfig"
355
356config BLK_DEV_ZONED_LOOP
357 tristate "Zoned loopback device support"
358 depends on BLK_DEV_ZONED
359 help
360 Saying Y here will allow you to use create a zoned block device using
361 regular files for zones (one file per zones). This is useful to test
362 file systems, device mapper and applications that support zoned block
363 devices. To create a zoned loop device, no user utility is needed, a
364 zoned loop device can be created (or re-started) using a command
365 like:
366
367 echo "add id=0,zone_size_mb=256,capacity_mb=16384,conv_zones=11" > \
368 /dev/zloop-control
369
370 See Documentation/admin-guide/blockdev/zoned_loop.rst for usage
371 details.
372
373 If unsure, say N.
374
375endif # BLK_DEV