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path: root/drivers/md/dm-ioctl.c (follow)
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* dm ioctl: report event number in DM_LIST_DEVICESMikulas Patocka2017-06-191-1/+5
| | | | | | | | | | | | | | | 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>
* dm ioctl: add a new DM_DEV_ARM_POLL ioctlMikulas Patocka2017-06-191-21/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* dm: add basic support for using the select or poll functionMikulas Patocka2017-06-191-1/+48
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* dm ioctl: restore __GFP_HIGH in copy_params()Junaid Shahid2017-05-231-2/+3
| | | | | | | | | | | | | | Commit d224e9381897 ("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: d224e9381897 ("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>
* drivers/md/dm-ioctl.c: use kvmalloc rather than opencoded variantMichal Hocko2017-05-091-9/+4
| | | | | | | | | | | | | | | | 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>
* dm: introduce enum dm_queue_mode to cleanup related codeBart Van Assche2017-04-271-1/+1
| | | | | | | | | 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>
* dm ioctl: prevent stack leak in dm ioctl callAdrian Salido2017-04-271-1/+1
| | | | | | | | | | | | | | 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>
* dm ioctl: remove double parenthesesMatthias Kaehlcke2017-04-241-2/+2
| | | | | | | | | | 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>
* dm: remove dummy dm_table definitionMikulas Patocka2017-04-241-8/+0
| | | | | | | | | | | 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>
* sched/headers: Prepare to move the memalloc_noio_*() APIs to <linux/sched/mm.h>Ingo Molnar2017-03-021-0/+1
| | | | | | | | | | | 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>
* Replace <asm/uaccess.h> with <linux/uaccess.h> globallyLinus Torvalds2016-12-241-1/+1
| | | | | | | | | | | | | 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>
* dm ioctl: use offsetof() instead of open-coding itBart Van Assche2016-12-081-1/+1
| | | | | | | | | | | 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>
* dm: allow bio-based table to be upgraded to bio-based with DAX supportToshi Kani2016-07-211-1/+10
| | | | | | | | | | | | | 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>
* dm ioctl: Simplify parameter buffer management codeBart Van Assche2016-07-011-12/+6
| | | | | | | | | | | 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>
* dm: move request-based code out to dm-rq.[hc]Mike Snitzer2016-06-101-1/+1
| | | | | | | | | | | | | | 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>
* dm ioctl: drop use of __GFP_REPEAT in copy_params()'s __vmalloc() callMichal Hocko2016-05-051-1/+1
| | | | | | | | 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>
* dm: allow immutable request-based targets to use blk-mq pduMike Snitzer2016-02-231-1/+1
| | | | | | | 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>
* dm: set DM_TARGET_WILDCARD feature on "error" targetMike Snitzer2016-02-221-1/+2
| | | | | | | | | | | | | 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>
* char: make misc_deregister a void functionGreg Kroah-Hartman2015-08-051-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* dm: only initialize the request_queue onceChristoph Hellwig2015-04-301-8/+9
| | | | | | | | | | | | | | | | | | | | | | | 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>
* dm ioctl: fix stale comment above dm_get_inactive_table()Junxiao Bi2015-02-091-2/+2
| | | | | | | 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>
* dm: enhance internal suspend and resume interfaceMike Snitzer2014-11-191-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* dm: allow active and inactive tables to share dm_devsBenjamin Marzinski2014-10-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* dm: allow remove to be deferredMikulas Patocka2013-11-101-6/+30
| | | | | | | | | | | | | | | | | | | | | | | | | 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>
* dm: add statistics supportMikulas Patocka2013-09-061-8/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* dm ioctl: cleanup error handling in table_loadMike Snitzer2013-09-061-18/+16
| | | | | | | Make use of common cleanup code. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm ioctl: increase granularity of type_lock when loading tableMike Snitzer2013-09-061-2/+4
| | | | | | | | | | | | | | | 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>
* dm ioctl: prevent rename to empty name or uuidAlasdair Kergon2013-09-061-1/+1
| | | | | | | | | | | | | | | 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>
* dm: optimize use SRCU and RCUMikulas Patocka2013-07-111-40/+82
| | | | | | | | | | | | | | | | | | | | | | 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>
* dm: use __GFP_HIGHMEM in __vmallocMikulas Patocka2013-07-111-1/+1
| | | | | | | | | | | | 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>
* dm ioctl: set noio flag to avoid __vmalloc deadlockMikulas Patocka2013-07-111-0/+3
| | | | | | | | | | | | | | Set noio flag while calling __vmalloc() because it doesn't fully respect gfp flags to avoid a possible deadlock (see commit 502624bdad3dba45dfaacaf36b7d83e39e74b2d2). 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>
* dm ioctl: allow message to return dataMikulas Patocka2013-03-011-1/+35
| | | | | | | | | | | | | | | | 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>
* dm ioctl: optimize functions without variable paramsMikulas Patocka2013-03-011-18/+34
| | | | | | | | | | | | | | | | | | | | 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>
* dm ioctl: introduce ioctl_flagsMikulas Patocka2013-03-011-23/+41
| | | | | | | | | | | 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>
* dm: fix truncated status stringsMikulas Patocka2013-03-011-5/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Avoid returning a truncated table or status string instead of setting the DM_BUFFER_FULL_FLAG when the last target of a table fills the buffer. When processing a table or status request, the function retrieve_status calls ti->type->status. If ti->type->status returns non-zero, retrieve_status assumes that the buffer overflowed and sets DM_BUFFER_FULL_FLAG. However, targets don't return non-zero values from their status method on overflow. Most targets returns always zero. If a buffer overflow happens in a target that is not the last in the table, it gets noticed during the next iteration of the loop in retrieve_status; but if a buffer overflow happens in the last target, it goes unnoticed and erroneously truncated data is returned. In the current code, the targets behave in the following way: * dm-crypt returns -ENOMEM if there is not enough space to store the key, but it returns 0 on all other overflows. * dm-thin returns errors from the status method if a disk error happened. This is incorrect because retrieve_status doesn't check the error code, it assumes that all non-zero values mean buffer overflow. * all the other targets always return 0. This patch changes the ti->type->status function to return void (because most targets don't use the return code). Overflow is detected in retrieve_status: if the status method fills up the remaining space completely, it is assumed that buffer overflow happened. Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm ioctl: use kmalloc if possibleMikulas Patocka2012-12-211-13/+32
| | | | | | | | | | | | | | | | | | If the parameter buffer is small enough, try to allocate it with kmalloc() rather than vmalloc(). vmalloc is noticeably slower than kmalloc because it has to manipulate page tables. In my tests, on PA-RISC this patch speeds up activation 13 times. On Opteron this patch speeds up activation by 5%. This patch introduces a new function free_params() to free the parameters and this uses new flags that record whether or not vmalloc() was used and whether or not the input buffer must be wiped after use. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm ioctl: remove PF_MEMALLOCMikulas Patocka2012-12-211-9/+4
| | | | | | | | When allocating memory for the userspace ioctl data, set some appropriate GPF flags directly instead of using PF_MEMALLOC. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm ioctl: prevent unsafe change to dm_ioctl data_sizeAlasdair G Kergon2012-12-211-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Abort dm ioctl processing if userspace changes the data_size parameter after we validated it but before we finished copying the data buffer from userspace. The dm ioctl parameters are processed in the following sequence: 1. ctl_ioctl() calls copy_params(); 2. copy_params() makes a first copy of the fixed-sized portion of the userspace parameters into the local variable "tmp"; 3. copy_params() then validates tmp.data_size and allocates a new structure big enough to hold the complete data and copies the whole userspace buffer there; 4. ctl_ioctl() reads userspace data the second time and copies the whole buffer into the pointer "param"; 5. ctl_ioctl() reads param->data_size without any validation and stores it in the variable "input_param_size"; 6. "input_param_size" is further used as the authoritative size of the kernel buffer. The problem is that userspace code could change the contents of user memory between steps 2 and 4. In particular, the data_size parameter can be changed to an invalid value after the kernel has validated it. This lets userspace force the kernel to access invalid kernel memory. The fix is to ensure that the size has not changed at step 4. This patch shouldn't have a security impact because CAP_SYS_ADMIN is required to run this code, but it should be fixed anyway. Reported-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: stable@kernel.org
* dm thin: commit before gathering statusAlasdair G Kergon2012-07-271-1/+4
| | | | | | | | | | | | | | | | Commit outstanding metadata before returning the status for a dm thin pool so that the numbers reported are as up-to-date as possible. The commit is not performed if the device is suspended or if the DM_NOFLUSH_FLAG is supplied by userspace and passed to the target through a new 'status_flags' parameter in the target's dm_status_fn. The userspace dmsetup tool will support the --noflush flag with the 'dmsetup status' and 'dmsetup wait' commands from version 1.02.76 onwards. Tested-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: reject trailing characters in sccanf inputMikulas Patocka2012-03-281-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | Device mapper uses sscanf to convert arguments to numbers. The problem is that the way we use it ignores additional unmatched characters in the scanned string. For example, this `if (sscanf(string, "%d", &number) == 1)' will match a number, but also it will match number with some garbage appended, like "123abc". As a result, device mapper accepts garbage after some numbers. For example the command `dmsetup create vg1-new --table "0 16384 linear 254:1bla 34816bla"' will pass without an error. This patch fixes all sscanf uses in device mapper. It appends "%c" with a pointer to a dummy character variable to every sscanf statement. The construct `if (sscanf(string, "%d%c", &number, &dummy) == 1)' succeeds only if string is a null-terminated number (optionally preceded by some whitespace characters). If there is some character appended after the number, sscanf matches "%c", writes the character to the dummy variable and returns 2. We check the return value for 1 and consequently reject numbers with some garbage appended. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm ioctl: do not leak argv if target message only contains whitespaceJesper Juhl2012-03-071-1/+1
| | | | | | | | | | | If 'argc' is zero we jump to the 'out:' label, but this leaks the (unused) memory that 'dm_split_args()' allocated for 'argv' if the string being split consisted entirely of whitespace. Jump to the 'out_argv:' label instead to free up that memory. Signed-off-by: Jesper Juhl <jj@chaosbits.net> Cc: stable@kernel.org Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm table: add immutable featureAlasdair G Kergon2011-10-311-0/+11
| | | | | | | | | | Introduce DM_TARGET_IMMUTABLE to indicate that the target type cannot be mixed with any other target type, and once loaded into a device, it cannot be replaced with a table containing a different type. The thin provisioning pool device will use this. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm ioctl: forbid multiple device specifiersMikulas Patocka2011-08-021-0/+6
| | | | | | | | | | Exactly one of name, uuid or device must be specified when referencing an existing device. This removes the ambiguity (risking the wrong device being updated) if two conflicting parameters were specified. Previously one parameter got used and any others were ignored silently. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm ioctl: introduce __get_dev_cellMikulas Patocka2011-08-021-17/+24
| | | | | | | | | Move logic to find device based on major/minor number to a separate function __get_dev_cell (similar to __get_uuid_cell and __get_name_cell). This makes the function __find_device_hash_cell more straightforward. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm ioctl: fill in device parameters in more ioctlsMikulas Patocka2011-08-021-27/+36
| | | | | | | | | | | | Move parameter filling from find_device to __find_device_hash_cell. This patch causes ioctls using __find_device_hash_cell (DM_DEV_REMOVE_CMD, DM_DEV_SUSPEND_CMD - resume, DM_TABLE_CLEAR_CMD) to return device parameters, bringing them into line with the other ioctls. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm ioctl: prevent empty messageAlasdair G Kergon2011-08-021-0/+5
| | | | | | | Detect invalid empty messages in core dm instead of requiring every target to check this. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm ioctl: add flag to wipe buffers for secure dataMilan Broz2011-03-241-2/+21
| | | | | | | | | | | | | | | | | | | Add DM_SECURE_DATA_FLAG which userspace can use to ensure that all buffers allocated for dm-ioctl are wiped immediately after use. The user buffer is wiped as well (we do not want to keep and return sensitive data back to userspace if the flag is set). Wiping is useful for cryptsetup to ensure that the key is present in memory only in defined places and only for the time needed. (For crypt, key can be present in table during load or table status, wait and message commands). Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm ioctl: prepare for crypt key wipingMilan Broz2011-03-241-14/+11
| | | | | | | | | Prepare code for implementing buffer wipe flag. No functional change in this patch. Signed-off-by: Milan Broz <mbroz@redhat.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm ioctl: suppress needless warning messagesMilan Broz2011-01-131-4/+4
| | | | | | | | | | | | The device-mapper should not send warning messages to syslog if a device is not found. This can be done by userspace according to the returned dm-ioctl error code. So move these messages to debug level and use rate limiting to not flood syslog. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm ioctl: allow rename to fill empty uuidPeter Jones2011-01-131-25/+78
| | | | | | | | | | | | | | | | | | | | | Allow the uuid of a mapped device to be set after device creation. Previously the uuid (which is optional) could only be set by DM_DEV_CREATE. If no uuid was supplied it could not be set later. Sometimes it's necessary to create the device before the uuid is known, and in such cases the uuid must be filled in after the creation. This patch extends DM_DEV_RENAME to accept a uuid accompanied by a new flag DM_UUID_FLAG. This can only be done once and if no uuid was previously supplied. It cannot be used to change an existing uuid. DM_VERSION_MINOR is also bumped to 19 to indicate this interface extension is available. Signed-off-by: Peter Jones <pjones@redhat.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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