kernel/linux.git/include/uapi/linux/nbd.h, branch v6.12.80

nbd: implement the WRITE_ZEROES command

2024-09-06T14:31:40+00:00

The NBD protocol defines a message for zeroing out a region of an export Add support to the kernel driver for that message. Signed-off-by: Wouter Verhelst Cc: Eric Blake Reviewed-by: Damien Le Moal Link: https://lore.kernel.org/r/20240812133032.115134-3-w@uter.be Signed-off-by: Jens Axboe

nbd: add support for rotational devices

2024-07-28T22:47:52+00:00

The NBD protocol defines the flag NBD_FLAG_ROTATIONAL to flag that the export in use should be treated as a rotational device. Add support for that flag to the kernel driver. Signed-off-by: Wouter Verhelst Reviewed-by: Eric Blake Link: https://lore.kernel.org/r/20240725164536.1275851-1-w@uter.be Signed-off-by: Jens Axboe

uapi nbd: add cookie alias to handle

2023-04-28T01:15:11+00:00

The uapi header declares a 'char handle[8]' per request; which is overloaded in English (are you referring to "handle" the verb, such as handling a signal or writing a callback handler, or "handle" the noun, the value used in a lookup table to correlate a response back to the request). Many user-space NBD implementations (both servers and clients) have instead used 'uint64_t cookie' or similar, as it is easier to directly assign an integer than to futz around with memcpy. In fact, upstream documentation is now encouraging this shift in terminology: https://github.com/NetworkBlockDevice/nbd/commit/ca4392eb2b Accomplish this by use of an anonymous union to provide the alias for anyone getting the definition from the uapi; this does not break existing clients, while exposing the nicer name for those who prefer it. Note that block/nbd.c still uses the term handle (in fact, it actually combines a 32-bit cookie and a 32-bit tag into the 64-bit handle), but that internal usage is not changed by the public uapi, since no compliant NBD server has any reason to inspect or alter the 64 bits sent over the socket. Signed-off-by: Eric Blake Reviewed-by: Josef Bacik Link: https://lore.kernel.org/r/20230410180611.1051618-3-eblake@redhat.com Signed-off-by: Jens Axboe

uapi nbd: improve doc links to userspace spec

2023-04-28T01:15:11+00:00

The uapi header intentionally documents only the NBD server features that the kernel module will utilize as a client. But while it already had one mention of skipped bits due to userspace extensions, it did not actually direct the reader to the canonical source to learn about those extensions. While touching comments, fix an outdated reference that listed only READ and WRITE as commands. Signed-off-by: Eric Blake Reviewed-by: Ming Lei Reviewed-by: Josef Bacik Link: https://lore.kernel.org/r/20230410180611.1051618-2-eblake@redhat.com Signed-off-by: Jens Axboe

nbd: Add the nbd NBD_DISCONNECT_ON_CLOSE config flag.

2018-06-21T01:10:06+00:00

If NBD_DISCONNECT_ON_CLOSE is set on a device, then the driver will issue a disconnect from nbd_release if the device has no remaining bdev->bd_openers. Fix ret val so reconfigure with only setting the flag succeeds. Reviewed-by: Josef Bacik Signed-off-by: Doron Roberts-Kedes Signed-off-by: Jens Axboe

License cleanup: add SPDX license identifier to uapi header files with a license

2017-11-02T10:20:11+00:00

Many user space API headers have licensing information, which is either incomplete, badly formatted or just a shorthand for referring to the license under which the file is supposed to be. This makes it hard for compliance tools to determine the correct license. Update these files with an SPDX license identifier. The identifier was chosen based on the license information in the file. GPL/LGPL licensed headers get the matching GPL/LGPL SPDX license identifier with the added 'WITH Linux-syscall-note' exception, which is the officially assigned exception identifier for the kernel syscall exception: NOTE! This copyright does *not* cover user programs that use kernel services by normal system calls - this is merely considered normal use of the kernel, and does *not* fall under the heading of "derived work". This exception makes it possible to include GPL headers into non GPL code, without confusing license compliance tools. Headers which have either explicit dual licensing or are just licensed under a non GPL license are updated with the corresponding SPDX identifier and the GPLv2 with syscall exception identifier. The format is: ((GPL-2.0 WITH Linux-syscall-note) OR SPDX-ID-OF-OTHER-LICENSE) SPDX license identifiers are a legally binding shorthand, which can be used instead of the full boiler plate text. The update does not remove existing license information as this has to be done on a case by case basis and the copyright holders might have to be consulted. This will happen in a separate step. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. See the previous patch in this series for the methodology of how this patch was researched. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

nbd: add FUA op support

2017-05-30T14:20:25+00:00

NBD userland client and server have FUA (forced unit access) support and flags defined. Make NBD kernel module recognize NBD_FLAG_SEND_FUA, enable FUA on the queue, and forward FUA requests to the server. Signed-off-by: Shaun McDowell Reviewed-by: Josef Bacik Signed-off-by: Jens Axboe

nbd: add a flag to destroy an nbd device on disconnect

2017-04-17T15:58:42+00:00

For ease of management it would be nice for users to specify that the device node for a nbd device is destroyed once it is disconnected and there are no more users. Add a client flag and enable this operation to happen. Signed-off-by: Josef Bacik Signed-off-by: Jens Axboe

nbd: move multi-connection bit to unused value

2016-11-22T20:11:55+00:00

Bit #7 is already used, move to bit #8 which is the first unused one. Fixes: 9561a7ade0c2 ("nbd: add multi-connection support") Signed-off-by: Jens Axboe

nbd: add multi-connection support

2016-11-22T19:16:32+00:00

NBD can become contended on its single connection. We have to serialize all writes and we can only process one read response at a time. Fix this by allowing userspace to provide multiple connections to a single nbd device. This coupled with block-mq drastically increases performance in multi-process cases. Thanks, Signed-off-by: Josef Bacik Signed-off-by: Jens Axboe