dm: update relevant MODULE_AUTHOR entries to latest dm-devel mailing list

Signed-off-by: Mike Snitzer <snitzer@kernel.org>

dm log userspace: replace deprecated strncpy with strscpy

`strncpy` is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.

`lc` is already zero-allocated:
| lc = kzalloc(sizeof(*lc), GFP_KERNEL);
... as such, any future NUL-padding is superfluous.

A suitable replacement is `strscpy` [2] due to the fact that it
guarantees NUL-termination on the destination buffer without
unnecessarily NUL-padding.

Let's also go with the more idiomatic `dest, src, sizeof(dest)` pattern
for destination buffers that the compiler can calculate the size for.

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
Link: https://github.com/KSPP/linux/issues/90
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Justin Stitt <justinstitt@google.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

dm: avoid void function return statements

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

dm: change "unsigned" to "unsigned int"

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

dm: add missing SPDX-License-Indentifiers

'GPL-2.0-only' is used instead of 'GPL-2.0' because SPDX has
deprecated its use.

Suggested-by: John Wiele <jwiele@redhat.com>
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

dm: update target status functions to support IMA measurement

For device mapper targets to take advantage of IMA's measurement
capabilities, the status functions for the individual targets need to be
updated to handle the status_type_t case for value STATUSTYPE_IMA.

Update status functions for the following target types, to log their
respective attributes to be measured using IMA.
01. cache
02. crypt
03. integrity
04. linear
05. mirror
06. multipath
07. raid
08. snapshot
09. striped
10. verity

For rest of the targets, handle the STATUSTYPE_IMA case by setting the
measurement buffer to NULL.

For IMA to measure the data on a given system, the IMA policy on the
system needs to be updated to have the following line, and the system
needs to be restarted for the measurements to take effect.

/etc/ima/ima-policy
measure func=CRITICAL_DATA label=device-mapper template=ima-buf

The measurements will be reflected in the IMA logs, which are located at:

/sys/kernel/security/integrity/ima/ascii_runtime_measurements
/sys/kernel/security/integrity/ima/binary_runtime_measurements

These IMA logs can later be consumed by various attestation clients
running on the system, and send them to external services for attesting
the system.

The DM target data measured by IMA subsystem can alternatively
be queried from userspace by setting DM_IMA_MEASUREMENT_FLAG with
DM_TABLE_STATUS_CMD.

Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

dm: convert to bioset_init()/mempool_init()

Convert dm to embedded bio sets.

Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

dm: drop NULL test before kmem_cache_destroy() and mempool_destroy()

Remove DM's unneeded NULL tests before calling these destroy functions,
now that they check for NULL, thanks to these v4.3 commits:
3942d2991 ("mm/slab_common: allow NULL cache pointer in kmem_cache_destroy()")
4e3ca3e03 ("mm/mempool: allow NULL `pool' pointer in mempool_destroy()")

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@ expression x; @@
-if (x != NULL)
\(kmem_cache_destroy\|mempool_destroy\|dma_pool_destroy\)(x);
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

dm log userspace base: fix compile warning

This fixes up a compile warning [-Wunused-but-set-variable] - given the
comment in userspace_set_region_sync() the non-reporting of errors is
intentional so the return value can be dropped to make gcc happy.

Also, fix typo in comment.

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

dm log userspace: split flush_entry_pool to be per dirty-log

Use a single slab cache to allocate a mempool for each dirty-log.
This _should_ eliminate DM's need for io_schedule_timeout() in
mempool_alloc(); so io_schedule() should be sufficient now.

Also, rename struct flush_entry to dm_dirty_log_flush_entry to allow
KMEM_CACHE() to create a meaningful global name for the slab cache.

Also, eliminate some holes in struct log_c by rearranging members.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Heinz Mauelshagen <heinzm@redhat.com>

dm: use time_in_range() and time_after()

To be future-proof and for better readability the time comparisons are modified
to use time_in_range() and time_after() instead of plain, error-prone math.

Signed-off-by: Manuel Schölling <manuel.schoelling@gmx.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

dm log userspace: allow mark requests to piggyback on flush requests

In the cluster evironment, cluster write has poor performance because
userspace_flush() has to contact a userspace program (cmirrord) for
clear/mark/flush requests. But both mark and flush requests require
cmirrord to communicate the message to all the cluster nodes for each
flush call. This behaviour is really slow.

To address this we now merge mark and flush requests together to reduce
the kernel-userspace-kernel time. We allow a new directive,
"integrated_flush" that can be used to instruct the kernel log code to
combine flush and mark requests when directed by userspace. If not
directed by userspace (due to an older version of the userspace code
perhaps), the kernel will function as it did previously - preserving
backwards compatibility. Additionally, flush requests are performed
lazily when only clear requests exist.

Signed-off-by: Dongmao Zhang <dmzhang@suse.com>
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

md: Add module.h to all files using it implicitly

A pending cleanup will mean that module.h won't be implicitly
everywhere anymore. Make sure the modular drivers in md dir
are actually calling out for <module.h> explicitly in advance.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

dm log userspace: add log device dependency

Allow userspace dm log implementations to register their log device so it
is no longer missing from the list of device dependencies.

When device mapper targets use a device they normally call dm_get_device
which includes it in the device list returned to userspace applications
such as LVM through the DM_TABLE_DEPS ioctl. Userspace log devices
don't use dm_get_device as userspace opens them so they are missing from
the list of dependencies.

This patch extends the DM_ULOG_CTR operation to allow userspace to
respond with the name of the log device (if appropriate) to be
registered via 'dm_get_device'. DM_ULOG_REQUEST_VERSION is incremented.

This is backwards compatible. If the kernel and userspace log server
have both been updated, the new information will be passed down to the
kernel and the device will be registered. If the kernel is new, but
the log server is old, the log server will not pass down any device
information and the kernel will simply bypass the device registration
as before. If the kernel is old but the log server is new, the log
server will see the old version number and not pass the device info.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

dm log userspace: fix comment hyphens

Fix comments: clustered-disk needs a hyphen not an underscore.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

dm log: userspace use list_move

Replace list_del() followed by list_add() with list_move().

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

dm log userspace: add version number to comms

This patch adds a 'version' field to the 'dm_ulog_request'
structure.

The 'version' field is taken from a portion of the unused
'padding' field in the 'dm_ulog_request' structure. This
was done to avoid changing the size of the structure and
possibly disrupting backwards compatibility.

The version number will help notify user-space daemons
when a change has been made to the kernel/userspace
log API.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

dm log userspace: group clear and mark requests

Allow the device-mapper log's 'mark' and 'clear' requests to be
grouped and processed in a batch. This can significantly reduce the
amount of traffic going between the kernel and userspace (where the
processing daemon resides).

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

dm log userspace: split flush queue

Split the 'flush_list', which contained a mix of both 'mark' and 'clear'
requests, into two distinct lists ('mark_list' and 'clear_list').

The device mapper log implementations (used by various DM targets) are
allowed to cache 'mark' and 'clear' requests until a 'flush' is
received. Until now, these cached requests were kept in the same list.
They will now be put into distinct lists to facilitate group processing
of these requests (in the next patch).

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

dm log userspace: trap all failed log construction errors

When constructing a mirror log, it is possible for the initial request
to fail for other reasons besides -ESRCH. These must be handled too.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

dm log: userspace fix incorrect luid cast in userspace_ctr

mips:

drivers/md/dm-log-userspace-base.c: In function `userspace_ctr':
drivers/md/dm-log-userspace-base.c:159: warning: cast from pointer to integer of different size

Cc: stable@kernel.org
Cc: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

md: Fix "strchr" [drivers/md/dm-log-userspace.ko] undefined!

Commit b8313b6da7e2e7c7f47d93d8561969a3ff9ba0ea ("dm log: remove incorrect
field from userspace table output") added a call to strstr() with a
single-character "needle" string parameter.

Unfortunately some versions of gcc replace such calls to strstr() by calls
to strchr() behind our back. This causes linking errors if strchr() is
defined as an inline function in <asm/string.h> (e.g. on m68k):

| WARNING: "strchr" [drivers/md/dm-log-userspace.ko] undefined!

Avoid this by explicitly calling strchr() instead.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

dm log: userspace add luid to distinguish between concurrent log instances

Device-mapper userspace logs (like the clustered log) are
identified by a universally unique identifier (UUID). This
identifier is used to associate requests from the kernel to
a specific log in userspace. The UUID must be unique everywhere,
since multiple machines may use this identifier when communicating
about a particular log, as is the case for cluster logs.

Sometimes, device-mapper/LVM may re-use a UUID. This is the
case during pvmoves, when moving from one segment of an LV
to another, or when resizing a mirror, etc. In these cases,
a new log is created with the same UUID and loaded in the
"inactive" slot. When a device-mapper "resume" is issued,
the "live" table is deactivated and the new "inactive" table
becomes "live". (The "inactive" table can also be removed
via a device-mapper 'clear' command.)

The above two issues were colliding. More than one log was being
created with the same UUID, and there was no way to distinguish
between them. So, sometimes the wrong log would be swapped
out during the exchange.

The solution is to create a locally unique identifier,
'luid', to go along with the UUID. This new identifier is used
to determine exactly which log is being referenced by the kernel
when the log exchange is made. The identifier is not
universally safe, but it does not need to be, since
create/destroy/suspend/resume operations are bound to a specific
machine; and these are the operations that make up the exchange.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

dm log: remove incorrect field from userspace table output

The output of 'dmsetup table' includes an internal field that should not
be there. This patch removes it. To make the fix simpler, we first
reorder a constructor argument

The 'device size' argument is generated internally. Currently it is
placed as the last space-separated word of the constructor string.
However, we need to use a version of the string without this word, so we
move it to the beginning instead so it is trivial to skip past it.

We keep a copy of the arguments passed to userspace for creating a log,
just in case we need to resend them. These are the same arguments that
are desired in the STATUSTYPE_TABLE request, except for one. When
creating the userspace log, the userspace daemon must know the size of
the mirror, so that is added to the arguments given in the constructor
table. We were printing this extra argument out as well, which is a
mistake.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

dm log: fix userspace status output

Fix 'dmsetup table' output.

There is a missing ' ' at the end of the string causing two
words to run together.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

dm raid1: add userspace log

This patch contains a device-mapper mirror log module that forwards
requests to userspace for processing.

The structures used for communication between kernel and userspace are
located in include/linux/dm-log-userspace.h. Due to the frequency,
diversity, and 2-way communication nature of the exchanges between
kernel and userspace, 'connector' was chosen as the interface for
communication.

The first log implementations written in userspace - "clustered-disk"
and "clustered-core" - support clustered shared storage. A userspace
daemon (in the LVM2 source code repository) uses openAIS/corosync to
process requests in an ordered fashion with the rest of the nodes in the
cluster so as to prevent log state corruption. Other implementations
with no association to LVM or openAIS/corosync, are certainly possible.

(Imagine if two machines are writing to the same region of a mirror.
They would both mark the region dirty, but you need a cluster-aware
entity that can handle properly marking the region clean when they are
done. Otherwise, you might clear the region when the first machine is
done, not the second.)

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>