Commit Graph

134 Commits

Author SHA1 Message Date
Mike Snitzer
61931c0ee9 dm: export dm_copy_name_and_uuid
Allow DM targets to access the configured name and uuid.
Also, bump DM ioctl version.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-10-01 15:03:40 -04:00
Linus Torvalds
2f12d44085 - DM multipath locking fixes around m->flags tests and improvements to
bio-based code so that it follows patterns established by
   request-based code.
 
 - Request-based DM core improvement to eliminate unnecessary call to
   blk_mq_queue_stopped().
 
 - Add "panic_on_corruption" error handling mode to DM verity target.
 
 - DM bufio fix to to perform buffer cleanup from a workqueue rather
   than wait for IO in reclaim context from shrinker.
 
 - DM crypt improvement to optionally avoid async processing via
   workqueues for reads and/or writes -- via "no_read_workqueue" and
   "no_write_workqueue" features.  This more direct IO processing
   improves latency and throughput with faster storage.  Avoiding
   workqueue IO submission for writes (DM_CRYPT_NO_WRITE_WORKQUEUE) is
   a requirement for adding zoned block device support to DM crypt.
 
 - Add zoned block device support to DM crypt.  Makes use of
   DM_CRYPT_NO_WRITE_WORKQUEUE and a new optional feature
   (DM_CRYPT_WRITE_INLINE) that allows write completion to wait for
   encryption to complete.  This allows write ordering to be preserved,
   which is needed for zoned block devices.
 
 - Fix DM ebs target's check for REQ_OP_FLUSH.
 
 - Fix DM core's report zones support to not report more zones than
   were requested.
 
 - A few small compiler warning fixes.
 
 - DM dust improvements to return output directly to the user rather
   than require they scrape the system log for output.
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Merge tag 'for-5.9/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper updates from Mike Snitzer:

 - DM multipath locking fixes around m->flags tests and improvements to
   bio-based code so that it follows patterns established by
   request-based code.

 - Request-based DM core improvement to eliminate unnecessary call to
   blk_mq_queue_stopped().

 - Add "panic_on_corruption" error handling mode to DM verity target.

 - DM bufio fix to to perform buffer cleanup from a workqueue rather
   than wait for IO in reclaim context from shrinker.

 - DM crypt improvement to optionally avoid async processing via
   workqueues for reads and/or writes -- via "no_read_workqueue" and
   "no_write_workqueue" features. This more direct IO processing
   improves latency and throughput with faster storage. Avoiding
   workqueue IO submission for writes (DM_CRYPT_NO_WRITE_WORKQUEUE) is a
   requirement for adding zoned block device support to DM crypt.

 - Add zoned block device support to DM crypt. Makes use of
   DM_CRYPT_NO_WRITE_WORKQUEUE and a new optional feature
   (DM_CRYPT_WRITE_INLINE) that allows write completion to wait for
   encryption to complete. This allows write ordering to be preserved,
   which is needed for zoned block devices.

 - Fix DM ebs target's check for REQ_OP_FLUSH.

 - Fix DM core's report zones support to not report more zones than were
   requested.

 - A few small compiler warning fixes.

 - DM dust improvements to return output directly to the user rather
   than require they scrape the system log for output.

* tag 'for-5.9/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm: don't call report zones for more than the user requested
  dm ebs: Fix incorrect checking for REQ_OP_FLUSH
  dm init: Set file local variable static
  dm ioctl: Fix compilation warning
  dm raid: Remove empty if statement
  dm verity: Fix compilation warning
  dm crypt: Enable zoned block device support
  dm crypt: add flags to optionally bypass kcryptd workqueues
  dm bufio: do buffer cleanup from a workqueue
  dm rq: don't call blk_mq_queue_stopped() in dm_stop_queue()
  dm dust: add interface to list all badblocks
  dm dust: report some message results directly back to user
  dm verity: add "panic_on_corruption" error handling mode
  dm mpath: use double checked locking in fast path
  dm mpath: rename current_pgpath to pgpath in multipath_prepare_ioctl
  dm mpath: rework __map_bio()
  dm mpath: factor out multipath_queue_bio
  dm mpath: push locking down to must_push_back_rq()
  dm mpath: take m->lock spinlock when testing QUEUE_IF_NO_PATH
  dm mpath: changes from initial m->flags locking audit
2020-08-07 13:08:09 -07:00
Damien Le Moal
1aeb6e7cd1 dm ioctl: Fix compilation warning
In retrieve_status(), when copying the target type name in the
target_type string field of struct dm_target_spec, copy at most
DM_MAX_TYPE_NAME - 1 character to avoid the compilation warning:

warning: ‘__builtin_strncpy’ specified bound 16 equals destination
size [-Wstringop-truncation]

when compiling with W-1.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-08-04 15:50:58 -04:00
Kees Cook
3f649ab728 treewide: Remove uninitialized_var() usage
Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings
(e.g. "unused variable"). If the compiler thinks it is uninitialized,
either simply initialize the variable or make compiler changes.

In preparation for removing[2] the[3] macro[4], remove all remaining
needless uses with the following script:

git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \
	xargs perl -pi -e \
		's/\buninitialized_var\(([^\)]+)\)/\1/g;
		 s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;'

drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid
pathological white-space.

No outstanding warnings were found building allmodconfig with GCC 9.3.0
for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64,
alpha, and m68k.

[1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/
[2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/
[3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/
[4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/

Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5
Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB
Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers
Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-16 12:35:15 -07:00
Gustavo A. R. Silva
da8996250a dm ioctl: use struct_size() helper in retrieve_deps()
One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct dm_target_deps {
      ...
        __u64 dev[0];   /* out */
};

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes.

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-17 12:31:45 -04:00
Mikulas Patocka
afa179eb60 dm: introduce DM_GET_TARGET_VERSION
This commit introduces a new ioctl DM_GET_TARGET_VERSION. It will load a
target that is specified in the "name" entry in the parameter structure
and return its version.

This functionality is intended to be used by cryptsetup, so that it can
query kernel capabilities before activating the device.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-09-16 10:18:01 -04:00
Mikulas Patocka
123d87d553 dm: make dm_table_find_target return NULL
Currently, if we pass too high sector number to dm_table_find_target, it
returns zeroed dm_target structure and callers test if the structure is
zeroed with the macro dm_target_is_valid.

However, returning NULL is common practice to indicate errors.

This patch refactors the dm code, so that dm_table_find_target returns
NULL and its callers test the returned value for NULL. The macro
dm_target_is_valid is deleted. In alloc_targets, we no longer allocate an
extra zeroed target.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-23 10:13:12 -04:00
Helen Koike
0f41fcf788 dm ioctl: fix hang in early create error condition
The dm_early_create() function (which deals with "dm-mod.create=" kernel
command line option) calls dm_hash_insert() who gets an extra reference
to the md object.

In case of failure, this reference wasn't being released, causing
dm_destroy() to hang, thus hanging the whole boot process.

Fix this by calling __hash_remove() in the error path.

Fixes: 6bbc923dfc ("dm: add support to directly boot to a mapped device")
Cc: stable@vger.kernel.org
Signed-off-by: Helen Koike <helen.koike@collabora.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-05-16 09:52:06 -04:00
Helen Koike
6bbc923dfc dm: add support to directly boot to a mapped device
Add a "create" module parameter, which allows device-mapper targets to
be configured at boot time. This enables early use of DM targets in the
boot process (as the root device or otherwise) without the need of an
initramfs.

The syntax used in the boot param is based on the concise format from
the dmsetup tool to follow the rule of least surprise:

	dmsetup table --concise /dev/mapper/lroot

Which is:
	dm-mod.create=<name>,<uuid>,<minor>,<flags>,<table>[,<table>+][;<name>,<uuid>,<minor>,<flags>,<table>[,<table>+]+]

Where,
	<name>		::= The device name.
	<uuid>		::= xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx | ""
	<minor>		::= The device minor number | ""
	<flags>		::= "ro" | "rw"
	<table>		::= <start_sector> <num_sectors> <target_type> <target_args>
	<target_type>	::= "verity" | "linear" | ...

For example, the following could be added in the boot parameters:
dm-mod.create="lroot,,,rw, 0 4096 linear 98:16 0, 4096 4096 linear 98:32 0" root=/dev/dm-0

Only the targets that were tested are allowed and the ones that don't
change any block device when the device is create as read-only. For
example, mirror and cache targets are not allowed. The rationale behind
this is that if the user makes a mistake, choosing the wrong device to
be the mirror or the cache can corrupt data.

The only targets initially allowed are:
* crypt
* delay
* linear
* snapshot-origin
* striped
* verity

Co-developed-by: Will Drewry <wad@chromium.org>
Co-developed-by: Kees Cook <keescook@chromium.org>
Co-developed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Helen Koike <helen.koike@collabora.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-03-05 14:53:50 -05:00
Wenwen Wang
800a7340ab dm ioctl: harden copy_params()'s copy_from_user() from malicious users
In copy_params(), the struct 'dm_ioctl' is first copied from the user
space buffer 'user' to 'param_kernel' and the field 'data_size' is
checked against 'minimum_data_size' (size of 'struct dm_ioctl' payload
up to its 'data' member).  If the check fails, an error code EINVAL will be
returned.  Otherwise, param_kernel->data_size is used to do a second copy,
which copies from the same user-space buffer to 'dmi'.  After the second
copy, only 'dmi->data_size' is checked against 'param_kernel->data_size'.
Given that the buffer 'user' resides in the user space, a malicious
user-space process can race to change the content in the buffer between
the two copies.  This way, the attacker can inject inconsistent data
into 'dmi' (versus previously validated 'param_kernel').

Fix redundant copying of 'minimum_data_size' from user-space buffer by
using the first copy stored in 'param_kernel'.  Also remove the
'data_size' check after the second copy because it is now unnecessary.

Cc: stable@vger.kernel.org
Signed-off-by: Wenwen Wang <wang6495@umn.edu>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-10-18 11:54:07 -04:00
Mike Snitzer
b2b04e7e2d dm: report which conflicting type caused error during table_load()
Eases troubleshooting to know the before vs after types.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-06-08 09:50:15 -04:00
Mike Snitzer
1eb5fa849f dm: allow targets to return output from messages they are sent
Could be useful for a target to return stats or other information.
If a target does DMEMIT() anything to @result from its .message method
then it must return 1 to the caller.

Signed-off-By: Mike Snitzer <snitzer@redhat.com>
2018-04-03 15:04:10 -04:00
Linus Torvalds
a9a08845e9 vfs: do bulk POLL* -> EPOLL* replacement
This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:

    for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
        L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
        for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
    done

with de-mangling cleanups yet to come.

NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do.  But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.

The next patch from Al will sort out the final differences, and we
should be all done.

Scripted-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-11 14:34:03 -08:00
Al Viro
afc9a42b74 the rest of drivers/*: annotate ->poll() instances
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-28 11:06:58 -05:00
Mikulas Patocka
62e082430e dm ioctl: fix alignment of event number in the device list
The size of struct dm_name_list is different on 32-bit and 64-bit
kernels (so "(nl + 1)" differs between 32-bit and 64-bit kernels).

This mismatch caused some harmless difference in padding when using 32-bit
or 64-bit kernel. Commit 23d70c5e52 ("dm ioctl: report event number in
DM_LIST_DEVICES") added reporting event number in the output of
DM_LIST_DEVICES_CMD. This difference in padding makes it impossible for
userspace to determine the location of the event number (the location
would be different when running on 32-bit and 64-bit kernels).

Fix the padding by using offsetof(struct dm_name_list, name) instead of
sizeof(struct dm_name_list) to determine the location of entries.

Also, the ioctl version number is incremented to 37 so that userspace
can use the version number to determine that the event number is present
and correctly located.

In addition, a global event is now raised when a DM device is created,
removed, renamed or when table is swapped, so that the user can monitor
for device changes.

Reported-by: Eugene Syromiatnikov <esyr@redhat.com>
Fixes: 23d70c5e52 ("dm ioctl: report event number in DM_LIST_DEVICES")
Cc: stable@vger.kernel.org # 4.13
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-09-25 11:18:29 -04:00
Eric Biggers
cf0dec6674 dm ioctl: constify ioctl lookup table
Constify the lookup table for device-mapper ioctls so that it is placed
in .rodata.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-08-28 11:47:18 -04:00
Mikulas Patocka
23d70c5e52 dm ioctl: report event number in DM_LIST_DEVICES
Report the event numbers for all the devices, so that the user doesn't
have to ask them one by one.  The event number is reported after the
name field in the dm_name_list structure.

The location of the next record is specified in the dm_name_list->next
field, that means that we can put the new data after the end of name and
it is backward compatible with the old code.  The old code just skips
the event number without interpreting it.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-06-19 11:03:50 -04:00
Mikulas Patocka
fc1841e1c1 dm ioctl: add a new DM_DEV_ARM_POLL ioctl
This ioctl will record the current global event number in the structure
dm_file, so that next select or poll call will wait until new events
arrived since this ioctl.

The DM_DEV_ARM_POLL ioctl has the same effect as closing and reopening
the handle.

Using the DM_DEV_ARM_POLL ioctl is optional - if the userspace is OK
with closing and reopening the /dev/mapper/control handle after select
or poll, there is no need to re-arm via ioctl.

Usage:
1. open the /dev/mapper/control device
2. send the DM_DEV_ARM_POLL ioctl
3. scan the event numbers of all devices we are interested in and process
   them
4. call select, poll or epoll on the handle (it waits until some new event
   happens since the DM_DEV_ARM_POLL ioctl)
5. go to step 2

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-06-19 11:03:49 -04:00
Mikulas Patocka
93e6442c76 dm: add basic support for using the select or poll function
Add the ability to poll on the /dev/mapper/control device.  The select
or poll function waits until any event happens on any dm device since
opening the /dev/mapper/control device.  When select or poll returns the
device as readable, we must close and reopen the device to wait for new
dm events.

Usage:
1. open the /dev/mapper/control device
2. scan the event numbers of all devices we are interested in and process
   them
3. call select, poll or epoll on the handle (it waits until some new event
   happens since opening the device)
4. close the /dev/mapper/control handle
5. go to step 1

The next commit allows to re-arm the polling without closing and
reopening the device.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-06-19 11:03:49 -04:00
Junaid Shahid
8c1e2162f2 dm ioctl: restore __GFP_HIGH in copy_params()
Commit d224e93818 ("drivers/md/dm-ioctl.c: use kvmalloc rather than
opencoded variant") left out the __GFP_HIGH flag when converting from
__vmalloc to kvmalloc.  This can cause the DM ioctl to fail in some low
memory situations where it wouldn't have failed earlier.  Add __GFP_HIGH
back to avoid any potential regression.

Fixes: d224e93818 ("drivers/md/dm-ioctl.c: use kvmalloc rather than opencoded variant")
Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-05-22 19:30:03 -04:00
Michal Hocko
d224e93818 drivers/md/dm-ioctl.c: use kvmalloc rather than opencoded variant
copy_params uses kmalloc with vmalloc fallback.  We already have a
helper for that - kvmalloc.  This caller requires GFP_NOIO semantic so
it hasn't been converted with many others by previous patches.  All we
need to achieve this semantic is to use the scope
memalloc_noio_{save,restore} around kvmalloc.

Link: http://lkml.kernel.org/r/20170306103327.2766-4-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-08 17:15:13 -07:00
Bart Van Assche
7e0d574f26 dm: introduce enum dm_queue_mode to cleanup related code
Introduce an enumeration type for the queue mode.  This patch does
not change any functionality but makes the DM code easier to read.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-04-27 17:08:44 -04:00
Adrian Salido
4617f564c0 dm ioctl: prevent stack leak in dm ioctl call
When calling a dm ioctl that doesn't process any data
(IOCTL_FLAGS_NO_PARAMS), the contents of the data field in struct
dm_ioctl are left initialized.  Current code is incorrectly extending
the size of data copied back to user, causing the contents of kernel
stack to be leaked to user.  Fix by only copying contents before data
and allow the functions processing the ioctl to override.

Cc: stable@vger.kernel.org
Signed-off-by: Adrian Salido <salidoa@google.com>
Reviewed-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-04-27 13:55:13 -04:00
Matthias Kaehlcke
e36215d87f dm ioctl: remove double parentheses
The extra pair of parantheses is not needed and causes clang to generate
warnings about the DM_DEV_CREATE_CMD comparison in validate_params().

Also remove another double parentheses that doesn't cause a warning.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-04-24 14:31:53 -04:00
Mikulas Patocka
9119fedddb dm: remove dummy dm_table definition
This dummy structure definition was required for RCU macros, but it
isn't required anymore, so delete it.

The dummy definition confuses the crash tool, see:
https://www.redhat.com/archives/dm-devel/2017-April/msg00197.html

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-04-24 12:04:35 -04:00
Ingo Molnar
5b3cc15aff sched/headers: Prepare to move the memalloc_noio_*() APIs to <linux/sched/mm.h>
Update the .c files that depend on these APIs.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:33 +01:00
Linus Torvalds
7c0f6ba682 Replace <asm/uaccess.h> with <linux/uaccess.h> globally
This was entirely automated, using the script by Al:

  PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
  sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
        $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)

to do the replacement at the end of the merge window.

Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-24 11:46:01 -08:00
Bart Van Assche
6080758d44 dm ioctl: use offsetof() instead of open-coding it
Subtracting sizes is a fragile approach because the result is only
correct if the compiler has not added any padding at the end of the
structure. Hence use offsetof() instead of size subtraction. An
additional advantage of offsetof() is that it makes the intent more
clear.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-12-08 14:13:08 -05:00
Toshi Kani
b5ab4a9ba5 dm: allow bio-based table to be upgraded to bio-based with DAX support
Allow table type DM_TYPE_BIO_BASED to extend with DM_TYPE_DAX_BIO_BASED
since DM_TYPE_DAX_BIO_BASED supports bio-based requests.

This is needed to allow a snapshot of an LV with DAX support to be
removed.  One of the intermediate table reloads that lvm2 does switches
from DM_TYPE_BIO_BASED to DM_TYPE_DAX_BIO_BASED.  No known reason to
disallow this so...

Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-07-20 23:49:52 -04:00
Bart Van Assche
028b39e314 dm ioctl: Simplify parameter buffer management code
Merge the two DM_PARAMS_[KV]MALLOC flags into a single flag.

Doing so avoids the crashes seen with previous attempts to consolidate
buffer management to use kvfree() without first flagging that memory had
actually been allocated.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-07-01 10:54:11 -04:00
Mike Snitzer
4cc96131af dm: move request-based code out to dm-rq.[hc]
Add some seperation between bio-based and request-based DM core code.

'struct mapped_device' and other DM core only structures and functions
have been moved to dm-core.h and all relevant DM core .c files have been
updated to include dm-core.h rather than dm.h

DM targets should _never_ include dm-core.h!

[block core merge conflict resolution from Stephen Rothwell]
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
2016-06-10 15:15:44 -04:00
Michal Hocko
72f6d8d8c9 dm ioctl: drop use of __GFP_REPEAT in copy_params()'s __vmalloc() call
copy_params()'s use of __GFP_REPEAT for the __vmalloc() call doesn't make much
sense because vmalloc doesn't rely on costly high order allocations.

Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-05-05 15:25:55 -04:00
Mike Snitzer
591ddcfc4b dm: allow immutable request-based targets to use blk-mq pdu
This will allow DM multipath to use a portion of the blk-mq pdu space
for target data (e.g. struct dm_mpath_io).

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-02-22 22:34:37 -05:00
Mike Snitzer
f083b09b78 dm: set DM_TARGET_WILDCARD feature on "error" target
The DM_TARGET_WILDCARD feature indicates that the "error" target may
replace any target; even immutable targets.  This feature will be useful
to preserve the ability to replace the "multipath" target even once it
is formally converted over to having the DM_TARGET_IMMUTABLE feature.

Also, implicit in the DM_TARGET_WILDCARD feature flag being set is that
.map, .map_rq, .clone_and_map_rq and .release_clone_rq are all defined
in the target_type.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-02-22 11:06:21 -05:00
Greg Kroah-Hartman
f368ed6088 char: make misc_deregister a void function
With well over 200+ users of this api, there are a mere 12 users that
actually checked the return value of this function.  And all of them
really didn't do anything with that information as the system or module
was shutting down no matter what.

So stop pretending like it matters, and just return void from
misc_deregister().  If something goes wrong in the call, you will get a
WARNING splat in the syslog so you know how to fix up your driver.
Other than that, there's nothing that can go wrong.

Cc: Alasdair Kergon <agk@redhat.com>
Cc: Neil Brown <neilb@suse.com>
Cc: Oleg Drokin <oleg.drokin@intel.com>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Wim Van Sebroeck <wim@iguana.be>
Cc: Christine Caulfield <ccaulfie@redhat.com>
Cc: David Teigland <teigland@redhat.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Acked-by: Joel Becker <jlbec@evilplan.org>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-05 10:35:49 -07:00
Christoph Hellwig
3e6180f0c8 dm: only initialize the request_queue once
Commit bfebd1cdb4 ("dm: add full blk-mq support to request-based DM")
didn't properly account for the need to short-circuit re-initializing
DM's blk-mq request_queue if it was already initialized.

Otherwise, reloading a blk-mq request-based DM table (either manually
or via multipathd) resulted in errors, see:
 https://www.redhat.com/archives/dm-devel/2015-April/msg00132.html

Fix is to only initialize the request_queue on the initial table load
(when the mapped_device type is assigned).

This is better than having dm_init_request_based_blk_mq_queue() return
early if the queue was already initialized because it elevates the
constraint to a more meaningful location in DM core.  As such the
pre-existing early return in dm_init_request_based_queue() can now be
removed.

Fixes: bfebd1cdb4 ("dm: add full blk-mq support to request-based DM")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-04-30 10:25:21 -04:00
Junxiao Bi
88e2f901e7 dm ioctl: fix stale comment above dm_get_inactive_table()
dm_table_put() was replaced by dm_put_live_table().

Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-02-09 13:06:48 -05:00
Mike Snitzer
ffcc393641 dm: enhance internal suspend and resume interface
Rename dm_internal_{suspend,resume} to dm_internal_{suspend,resume}_fast
-- dm-stats will continue using these methods to avoid all the extra
suspend/resume logic that is not needed in order to quickly flush IO.

Introduce dm_internal_suspend_noflush() variant that actually calls the
mapped_device's target callbacks -- otherwise target-specific hooks are
avoided (e.g. dm-thin's thin_presuspend and thin_postsuspend).  Common
code between dm_internal_{suspend_noflush,resume} and
dm_{suspend,resume} was factored out as __dm_{suspend,resume}.

Update dm_internal_{suspend_noflush,resume} to always take and release
the mapped_device's suspend_lock.  Also update dm_{suspend,resume} to be
aware of potential for DM_INTERNAL_SUSPEND_FLAG to be set and respond
accordingly by interruptibly waiting for the DM_INTERNAL_SUSPEND_FLAG to
be cleared.  Add lockdep annotation to dm_suspend() and dm_resume().

The existing DM_SUSPEND_FLAG remains unchanged.
DM_INTERNAL_SUSPEND_FLAG is set by dm_internal_suspend_noflush() and
cleared by dm_internal_resume().

Both DM_SUSPEND_FLAG and DM_INTERNAL_SUSPEND_FLAG may be set if a device
was already suspended when dm_internal_suspend_noflush() was called --
this can be thought of as a "nested suspend".  A "nested suspend" can
occur with legacy userspace dm-thin code that might suspend all active
thin volumes before suspending the pool for resize.

But otherwise, in the normal dm-thin-pool suspend case moving forward:
the thin-pool will have DM_SUSPEND_FLAG set and all active thins from
that thin-pool will have DM_INTERNAL_SUSPEND_FLAG set.

Also add DM_INTERNAL_SUSPEND_FLAG to status report.  This new
DM_INTERNAL_SUSPEND_FLAG state is being reported to assist with
debugging (e.g. 'dmsetup info' will report an internally suspended
device accordingly).

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
2014-11-19 12:31:17 -05:00
Benjamin Marzinski
86f1152b11 dm: allow active and inactive tables to share dm_devs
Until this change, when loading a new DM table, DM core would re-open
all of the devices in the DM table.  Now, DM core will avoid redundant
device opens (and closes when destroying the old table) if the old
table already has a device open using the same mode.  This is achieved
by managing reference counts on the table_devices that DM core now
stores in the mapped_device structure (rather than in the dm_table
structure).  So a mapped_device's active and inactive dm_tables' dm_dev
lists now just point to the dm_devs stored in the mapped_device's
table_devices list.

This improvement in DM core's device reference counting has the
side-effect of fixing a long-standing limitation of the multipath
target: a DM multipath table couldn't include any paths that were unusable
(failed).  For example: if all paths have failed and you add a new,
working, path to the table; you can't use it since the table load would
fail due to it still containing failed paths.  Now a re-load of a
multipath table can include failed devices and when those devices become
active again they can be used instantly.

The device list code in dm.c isn't a straight copy/paste from the code in
dm-table.c, but it's very close (aside from some variable renames).  One
subtle difference is that find_table_device for the tables_devices list
will only match devices with the same name and mode.  This is because we
don't want to upgrade a device's mode in the active table when an
inactive table is loaded.

Access to the mapped_device structure's tables_devices list requires a
mutex (tables_devices_lock), so that tables cannot be created and
destroyed concurrently.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-10-05 20:03:35 -04:00
Mikulas Patocka
2c140a246d dm: allow remove to be deferred
This patch allows the removal of an open device to be deferred until
it is closed.  (Previously such a removal attempt would fail.)

The deferred remove functionality is enabled by setting the flag
DM_DEFERRED_REMOVE in the ioctl structure on DM_DEV_REMOVE or
DM_REMOVE_ALL ioctl.

On return from DM_DEV_REMOVE, the flag DM_DEFERRED_REMOVE indicates if
the device was removed immediately or flagged to be removed on close -
if the flag is clear, the device was removed.

On return from DM_DEV_STATUS and other ioctls, the flag
DM_DEFERRED_REMOVE is set if the device is scheduled to be removed on
closure.

A device that is scheduled to be deleted can be revived using the
message "@cancel_deferred_remove". This message clears the
DMF_DEFERRED_REMOVE flag so that the device won't be deleted on close.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-11-09 18:20:22 -05:00
Mikulas Patocka
fd2ed4d252 dm: add statistics support
Support the collection of I/O statistics on user-defined regions of
a DM device.  If no regions are defined no statistics are collected so
there isn't any performance impact.  Only bio-based DM devices are
currently supported.

Each user-defined region specifies a starting sector, length and step.
Individual statistics will be collected for each step-sized area within
the range specified.

The I/O statistics counters for each step-sized area of a region are
in the same format as /sys/block/*/stat or /proc/diskstats but extra
counters (12 and 13) are provided: total time spent reading and
writing in milliseconds.  All these counters may be accessed by sending
the @stats_print message to the appropriate DM device via dmsetup.

The creation of DM statistics will allocate memory via kmalloc or
fallback to using vmalloc space.  At most, 1/4 of the overall system
memory may be allocated by DM statistics.  The admin can see how much
memory is used by reading
/sys/module/dm_mod/parameters/stats_current_allocated_bytes

See Documentation/device-mapper/statistics.txt for more details.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-09-05 20:46:06 -04:00
Mike Snitzer
f11c1c5693 dm ioctl: cleanup error handling in table_load
Make use of common cleanup code.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-09-05 20:46:06 -04:00
Mike Snitzer
00c4fc3b1f dm ioctl: increase granularity of type_lock when loading table
Hold the mapped device's type_lock before calling populate_table() since
it is where the table's type is determined based on the specified
targets.  There is no need to allow concurrent table loads to race to
establish the table's targets or type.

This eliminates the need to grab the lock in dm_table_set_type().

Also verify that the type_lock is held in both dm_set_md_type() and
dm_get_md_type().

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-09-05 20:46:06 -04:00
Alasdair Kergon
c2b0482462 dm ioctl: prevent rename to empty name or uuid
A device-mapper device must always have a name consisting of a non-empty
string.  If the device also has a uuid, this similarly must not be an
empty string.

The DM_DEV_CREATE ioctl enforces these rules when the device is created,
but this patch is needed to enforce them when DM_DEV_RENAME is used to
change the name or uuid.

Reported-by: Zdenek Kabelac <zkabelac@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
2013-09-05 20:46:06 -04:00
Mikulas Patocka
83d5e5b0af dm: optimize use SRCU and RCU
This patch removes "io_lock" and "map_lock" in struct mapped_device and
"holders" in struct dm_table and replaces these mechanisms with
sleepable-rcu.

Previously, the code would call "dm_get_live_table" and "dm_table_put" to
get and release table. Now, the code is changed to call "dm_get_live_table"
and "dm_put_live_table". dm_get_live_table locks sleepable-rcu and
dm_put_live_table unlocks it.

dm_get_live_table_fast/dm_put_live_table_fast can be used instead of
dm_get_live_table/dm_put_live_table. These *_fast functions use
non-sleepable RCU, so the caller must not block between them.

If the code changes active or inactive dm table, it must call
dm_sync_table before destroying the old table.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-07-10 23:41:18 +01:00
Mikulas Patocka
220cd058d9 dm: use __GFP_HIGHMEM in __vmalloc
Use __GFP_HIGHMEM in __vmalloc.

Pages allocated with __vmalloc can be allocated in high memory that is not
directly mapped to kernel space, so use __GFP_HIGHMEM just like vmalloc
does. This patch reduces memory pressure slightly because pages can be
allocated in the high zone.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-07-10 23:41:16 +01:00
Mikulas Patocka
1c0e883e86 dm ioctl: set noio flag to avoid __vmalloc deadlock
Set noio flag while calling __vmalloc() because it doesn't fully respect
gfp flags to avoid a possible deadlock (see commit
502624bdad).

This should be backported to stable kernels 3.8 and newer. The kernel 3.8
doesn't have memalloc_noio_save(), so we should set and restore process
flag PF_MEMALLOC instead.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-07-10 23:41:15 +01:00
Mikulas Patocka
a26062416e dm ioctl: allow message to return data
This patch introduces enhanced message support that allows the
device-mapper core to recognise messages that are common to all devices,
and for messages to return data to userspace.

Core messages are processed by the function "message_for_md".  If the
device mapper doesn't support the message, it is passed to the target
driver.

If the message returns data, the kernel sets the flag
DM_MESSAGE_OUT_FLAG.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:49 +00:00
Mikulas Patocka
02cde50b7e dm ioctl: optimize functions without variable params
Device-mapper ioctls receive and send data in a buffer supplied
by userspace.  The buffer has two parts.  The first part contains
a 'struct dm_ioctl' and has a fixed size.  The second part depends
on the ioctl and has a variable size.

This patch recognises the specific ioctls that do not use the variable
part of the buffer and skips allocating memory for it.

In particular, when a device is suspended and a resume ioctl is sent,
this now avoid memory allocation completely.

The variable "struct dm_ioctl tmp" is moved from the function
copy_params to its caller ctl_ioctl and renamed to param_kernel.
It is used directly when the ioctl function doesn't need any arguments.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:49 +00:00
Mikulas Patocka
e2914cc26b dm ioctl: introduce ioctl_flags
This patch introduces flags for each ioctl function.

So far, one flag is defined, IOCTL_FLAGS_NO_PARAMS.  It is set if the
function processing the ioctl doesn't take or produce any parameters in
the section of the data buffer that has a variable size.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:48 +00:00