linux.git/arch/um/os-Linux/file.c, branch v6.7 Linux kernel source tree um: Fix WRITE_ZEROES in the UBD Driver 2022-03-11T09:46:34+00:00 Frédéric Danis frederic.danis@collabora.com 2022-01-25T17:14:05+00:00 d2a0a616ab2246aab9527eeacf86a033679c8b22 Call to fallocate with FALLOC_FL_PUNCH_HOLE on a device backed by a sparse file can end up by missing data, zeroes data range, if the underlying file is used with a tool like bmaptool which will referenced only used spaces. Signed-off-by: Frédéric Danis <frederic.danis@collabora.com> Acked-by: Anton Ivanov <anton.ivanov@cambridgegreys.com> Signed-off-by: Richard Weinberger <richard@nod.at> 
Call to fallocate with FALLOC_FL_PUNCH_HOLE on a device backed by a sparse
file can end up by missing data, zeroes data range, if the underlying file
is used with a tool like bmaptool which will referenced only used spaces.

Signed-off-by: Frédéric Danis <frederic.danis@collabora.com>
Acked-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
um: Use fdatasync() when mapping the UBD FSYNC command 2020-06-02T20:37:55+00:00 Anton Ivanov anton.ivanov@cambridgegreys.com 2020-04-22T16:00:01+00:00 54ebe4060fe6c4ab76c79354417612ac9cf4f95e We do not need to update the metadata (atime, mtime, etc) on the UBD file and/or the COW file until UML exits. UBD image mtime is checked in UML only when opening the files. After that they are locked and used exclusively by a single UML instance, so there is no point wasting resources on updating metadata on every sync. We can sync data only. The host will always update mtime if a file has been modified upon closing it. Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com> Signed-off-by: Richard Weinberger <richard@nod.at> 
We do not need to update the metadata (atime, mtime, etc)
on the UBD file and/or the COW file until UML exits.

UBD image mtime is checked in UML only when opening
the files. After that they are locked and used
exclusively by a single UML instance, so there is
no point wasting resources on updating metadata on
every sync. We can sync data only. The host will
always update mtime if a file has been modified upon
closing it.

Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
um: Add include: memset() and memcpy() are in <string.h> 2020-06-02T20:37:11+00:00 Zach van Rijn me@zv.io 2020-04-01T21:30:48+00:00 38bccfbeb0af039e59eb75fe6d9b2a83cda3d381 These two functions are otherwise unknown to the pedantic compiler. Include the correct header to enable the build to succeed. Signed-off-by: Zach van Rijn <me@zv.io> Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com> Signed-off-by: Richard Weinberger <richard@nod.at> 
These two functions are otherwise unknown to the pedantic compiler.
Include the correct header to enable the build to succeed.

Signed-off-by: Zach van Rijn <me@zv.io>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
um: Implement time-travel=ext 2020-03-29T21:29:08+00:00 Johannes Berg johannes.berg@intel.com 2020-02-13T13:26:47+00:00 88ce642492339f49a0b391af40e5798c08948e49 This implements synchronized time-travel mode which - using a special application on a unix socket - lets multiple machines take part in a time-travelling simulation together. The protocol for the unix domain socket is defined in the new file include/uapi/linux/um_timetravel.h. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at> 
This implements synchronized time-travel mode which - using a special
application on a unix socket - lets multiple machines take part in a
time-travelling simulation together.

The protocol for the unix domain socket is defined in the new file
include/uapi/linux/um_timetravel.h.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
um: falloc.h needs to be directly included for older libc 2020-03-29T21:21:42+00:00 Alan Maguire alan.maguire@oracle.com 2020-03-17T17:35:34+00:00 35f3401317a3b26aa01fde8facfd320f2628fdcc When building UML with glibc 2.17 installed, compilation of arch/um/os-Linux/file.c fails due to failure to find FALLOC_FL_PUNCH_HOLE and FALLOC_FL_KEEP_SIZE definitions. It appears that /usr/include/bits/fcntl-linux.h (indirectly included by /usr/include/fcntl.h) does not include falloc.h with an older glibc, whereas a more up-to-date version does. Adding the direct include to file.c resolves the issue and does not cause problems for more recent glibc. Fixes: 50109b5a03b4 ("um: Add support for DISCARD in the UBD Driver") Cc: Brendan Higgins <brendanhiggins@google.com> Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Reviewed-by: Brendan Higgins <brendanhiggins@google.com> Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com> Signed-off-by: Richard Weinberger <richard@nod.at> 
When building UML with glibc 2.17 installed, compilation
of arch/um/os-Linux/file.c fails due to failure to find
FALLOC_FL_PUNCH_HOLE and FALLOC_FL_KEEP_SIZE definitions.

It appears that /usr/include/bits/fcntl-linux.h (indirectly
included by /usr/include/fcntl.h) does not include falloc.h
with an older glibc, whereas a more up-to-date version
does.

Adding the direct include to file.c resolves the issue
and does not cause problems for more recent glibc.

Fixes: 50109b5a03b4 ("um: Add support for DISCARD in the UBD Driver")
Cc: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
um: ubd: use 64-bit time_t where possible 2019-12-18T17:07:31+00:00 Arnd Bergmann arnd@arndb.de 2019-11-05T08:39:51+00:00 853bc0ab341b0c99619f83f4060dedcccad77b2a The ubd code suffers from a possible y2038 overflow on 32-bit architectures, both for the cow header and the os_file_modtime() function. Replace time_t with time64_t to extend the ubd_kern side as much as possible. Whether this makes a difference for the user side depends on the host libc implementation that may use either 32-bit or 64-bit time_t. For the cow file format, the header contains an unsigned 32-bit timestamp, which is good until y2106, passing this through a 'long long' gives us a consistent interpretation between 32-bit and 64-bit um kernels. Signed-off-by: Arnd Bergmann <arnd@arndb.de> 
The ubd code suffers from a possible y2038 overflow on 32-bit
architectures, both for the cow header and the os_file_modtime()
function.

Replace time_t with time64_t to extend the ubd_kern side as much
as possible.

Whether this makes a difference for the user side depends on
the host libc implementation that may use either 32-bit or 64-bit
time_t.

For the cow file format, the header contains an unsigned 32-bit
timestamp, which is good until y2106, passing this through a
'long long' gives us a consistent interpretation between 32-bit
and 64-bit um kernels.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
um: Add SPDX headers for files in arch/um/os-Linux 2019-09-15T19:37:17+00:00 Alex Dewar alex.dewar@gmx.co.uk 2019-08-25T09:49:18+00:00 97870c34b453251cda9c2341f8534b78003a74dc Convert files to use SPDX header. All files are licensed under the GPLv2. Signed-off-by: Alex Dewar <alex.dewar@gmx.co.uk> Signed-off-by: Richard Weinberger <richard@nod.at> 
Convert files to use SPDX header. All files are licensed under the GPLv2.

Signed-off-by: Alex Dewar <alex.dewar@gmx.co.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
um: drivers: Add virtio vhost-user driver 2019-09-15T19:37:15+00:00 Erel Geron erelx.geron@intel.com 2019-09-11T12:51:20+00:00 5d38f324993f49d1226ec81efe045834b46cd85a This module allows virtio devices to be used over a vhost-user socket. Signed-off-by: Erel Geron <erelx.geron@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at> 
This module allows virtio devices to be used over a vhost-user socket.

Signed-off-by: Erel Geron <erelx.geron@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
um: Add support for DISCARD in the UBD Driver 2018-12-27T21:48:20+00:00 Anton Ivanov anton.ivanov@cambridgegreys.com 2018-11-14T18:41:09+00:00 50109b5a03b4024eb6b8df3ab8f427625f54fe92 Support for DISCARD and WRITE_ZEROES in the ubd driver using fallocate. DISCARD is enabled by default and can be disabled using a new UBD command line flag. If the underlying fs on which the UBD image is stored does not support DISCARD the support for both DISCARD and WRITE_ZEROES is turned off. Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com> Signed-off-by: Richard Weinberger <richard@nod.at> 
Support for DISCARD and WRITE_ZEROES in the ubd driver using
fallocate.

DISCARD is enabled by default and can be disabled using a new
UBD command line flag.

If the underlying fs on which the UBD image is stored does not
support DISCARD the support for both DISCARD and WRITE_ZEROES
is turned off.

Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
um: Compile with modern headers 2018-03-29T20:15:12+00:00 Jason A. Donenfeld Jason@zx2c4.com 2017-12-14T02:23:37+00:00 530ba6c7cb3c22435a4d26de47037bb6f86a5329 Recent libcs have gotten a bit more strict, so we actually need to include the right headers and use the right types. This enables UML to compile again. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Cc: stable@vger.kernel.org Signed-off-by: Richard Weinberger <richard@nod.at> 
Recent libcs have gotten a bit more strict, so we actually need to
include the right headers and use the right types. This enables UML to
compile again.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: stable@vger.kernel.org
Signed-off-by: Richard Weinberger <richard@nod.at>