24 Aug, 2017
1 commit
-
This way we don't need a block_device structure to submit I/O. The
block_device has different life time rules from the gendisk and
request_queue and is usually only available when the block device node
is open. Other callers need to explicitly create one (e.g. the lightnvm
passthrough code, or the new nvme multipathing code).For the actual I/O path all that we need is the gendisk, which exists
once per block device. But given that the block layer also does
partition remapping we additionally need a partition index, which is
used for said remapping in generic_make_request.Note that all the block drivers generally want request_queue or
sometimes the gendisk, so this removes a layer of indirection all
over the stack.Signed-off-by: Christoph Hellwig
Signed-off-by: Jens Axboe
04 Jul, 2017
1 commit
-
Pull core block/IO updates from Jens Axboe:
"This is the main pull request for the block layer for 4.13. Not a huge
round in terms of features, but there's a lot of churn related to some
core cleanups.Note this depends on the UUID tree pull request, that Christoph
already sent out.This pull request contains:
- A series from Christoph, unifying the error/stats codes in the
block layer. We now use blk_status_t everywhere, instead of using
different schemes for different places.- Also from Christoph, some cleanups around request allocation and IO
scheduler interactions in blk-mq.- And yet another series from Christoph, cleaning up how we handle
and do bounce buffering in the block layer.- A blk-mq debugfs series from Bart, further improving on the support
we have for exporting internal information to aid debugging IO
hangs or stalls.- Also from Bart, a series that cleans up the request initialization
differences across types of devices.- A series from Goldwyn Rodrigues, allowing the block layer to return
failure if we will block and the user asked for non-blocking.- Patch from Hannes for supporting setting loop devices block size to
that of the underlying device.- Two series of patches from Javier, fixing various issues with
lightnvm, particular around pblk.- A series from me, adding support for write hints. This comes with
NVMe support as well, so applications can help guide data placement
on flash to improve performance, latencies, and write
amplification.- A series from Ming, improving and hardening blk-mq support for
stopping/starting and quiescing hardware queues.- Two pull requests for NVMe updates. Nothing major on the feature
side, but lots of cleanups and bug fixes. From the usual crew.- A series from Neil Brown, greatly improving the bio rescue set
support. Most notably, this kills the bio rescue work queues, if we
don't really need them.- Lots of other little bug fixes that are all over the place"
* 'for-4.13/block' of git://git.kernel.dk/linux-block: (217 commits)
lightnvm: pblk: set line bitmap check under debug
lightnvm: pblk: verify that cache read is still valid
lightnvm: pblk: add initialization check
lightnvm: pblk: remove target using async. I/Os
lightnvm: pblk: use vmalloc for GC data buffer
lightnvm: pblk: use right metadata buffer for recovery
lightnvm: pblk: schedule if data is not ready
lightnvm: pblk: remove unused return variable
lightnvm: pblk: fix double-free on pblk init
lightnvm: pblk: fix bad le64 assignations
nvme: Makefile: remove dead build rule
blk-mq: map all HWQ also in hyperthreaded system
nvmet-rdma: register ib_client to not deadlock in device removal
nvme_fc: fix error recovery on link down.
nvmet_fc: fix crashes on bad opcodes
nvme_fc: Fix crash when nvme controller connection fails.
nvme_fc: replace ioabort msleep loop with completion
nvme_fc: fix double calls to nvme_cleanup_cmd()
nvme-fabrics: verify that a controller returns the correct NQN
nvme: simplify nvme_dev_attrs_are_visible
...
15 Jun, 2017
1 commit
-
This reverts commit 12a7cf5ba6c776a2621d8972c7d42e8d3d959d20.
This commit apparently attempted to fix an issue that didn't really
exist, furthermore: this commit is the source of deadlocks and crashes
seen in multiple cases related to failing the primary mirror dev while
syncing.Reported-by: Jonathan Brassow
Signed-off-by: Mike Snitzer
12 Jun, 2017
1 commit
-
We've already got a few conflicts and upcoming work depends on some of the
changes that have gone into mainline as regression fixes for this series.Pull in 4.12-rc5 to resolve these conflicts and make it easier on down stream
trees to continue working on 4.13 changes.Signed-off-by: Jens Axboe
09 Jun, 2017
4 commits
-
Replace bi_error with a new bi_status to allow for a clear conversion.
Note that device mapper overloaded bi_error with a private value, which
we'll have to keep arround at least for now and thus propagate to a
proper blk_status_t value.Signed-off-by: Christoph Hellwig
Signed-off-by: Jens Axboe -
Turn the error paramter into a pointer so that target drivers can change
the value, and make sure only DM_ENDIO_* values are returned from the
methods.Signed-off-by: Christoph Hellwig
Signed-off-by: Mike Snitzer
Signed-off-by: Jens Axboe -
Instead use the special DM_MAPIO_KILL return value to return -EIO just
like we do for the request based path. Note that dm-log-writes returned
-ENOMEM in a few places, which now becomes -EIO instead. No consumer
treats -ENOMEM special so this shouldn't be an issue (and it should
use a mempool to start with to make guaranteed progress).Signed-off-by: Christoph Hellwig
Signed-off-by: Mike Snitzer
Signed-off-by: Jens Axboe -
A few (but not all) dm targets use a special EWOULDBLOCK error code for
failing REQ_RAHEAD requests that fail due to a lack of available resources.
But no one else knows about this magic code, and lower level drivers also
don't generate it when failing read-ahead requests for similar reasons.So remove this special casing and ignore all additional error handling for
REQ_RAHEAD - if this was a real underlying error we'd get a normal read
once the real read comes in.Signed-off-by: Christoph Hellwig
Reviewed-by: Bart Van Assche
Signed-off-by: Mike Snitzer
Signed-off-by: Jens Axboe
31 May, 2017
1 commit
-
Commit b685d3d65ac7 ("block: treat REQ_FUA and REQ_PREFLUSH as
synchronous") removed REQ_SYNC flag from WRITE_{FUA|PREFLUSH|...}
definitions. generic_make_request_checks() however strips REQ_FUA and
REQ_PREFLUSH flags from a bio when the storage doesn't report volatile
write cache and thus write effectively becomes asynchronous which can
lead to performance regressions.Fix the problem by making sure all bios which are synchronous are
properly marked with REQ_SYNC.Fixes: b685d3d65ac7 ("block: treat REQ_FUA and REQ_PREFLUSH as synchronous")
Cc: stable@vger.kernel.org
Signed-off-by: Jan Kara
Signed-off-by: Mike Snitzer
09 Apr, 2017
1 commit
-
Now that we use the proper REQ_OP_WRITE_ZEROES operation everywhere we can
kill this hack.Signed-off-by: Christoph Hellwig
Reviewed-by: Martin K. Petersen
Reviewed-by: Hannes Reinecke
Signed-off-by: Jens Axboe
14 Dec, 2016
1 commit
-
Pull block layer updates from Jens Axboe:
"This is the main block pull request this series. Contrary to previous
release, I've kept the core and driver changes in the same branch. We
always ended up having dependencies between the two for obvious
reasons, so makes more sense to keep them together. That said, I'll
probably try and keep more topical branches going forward, especially
for cycles that end up being as busy as this one.The major parts of this pull request is:
- Improved support for O_DIRECT on block devices, with a small
private implementation instead of using the pig that is
fs/direct-io.c. From Christoph.- Request completion tracking in a scalable fashion. This is utilized
by two components in this pull, the new hybrid polling and the
writeback queue throttling code.- Improved support for polling with O_DIRECT, adding a hybrid mode
that combines pure polling with an initial sleep. From me.- Support for automatic throttling of writeback queues on the block
side. This uses feedback from the device completion latencies to
scale the queue on the block side up or down. From me.- Support from SMR drives in the block layer and for SD. From Hannes
and Shaun.- Multi-connection support for nbd. From Josef.
- Cleanup of request and bio flags, so we have a clear split between
which are bio (or rq) private, and which ones are shared. From
Christoph.- A set of patches from Bart, that improve how we handle queue
stopping and starting in blk-mq.- Support for WRITE_ZEROES from Chaitanya.
- Lightnvm updates from Javier/Matias.
- Supoort for FC for the nvme-over-fabrics code. From James Smart.
- A bunch of fixes from a whole slew of people, too many to name
here"* 'for-4.10/block' of git://git.kernel.dk/linux-block: (182 commits)
blk-stat: fix a few cases of missing batch flushing
blk-flush: run the queue when inserting blk-mq flush
elevator: make the rqhash helpers exported
blk-mq: abstract out blk_mq_dispatch_rq_list() helper
blk-mq: add blk_mq_start_stopped_hw_queue()
block: improve handling of the magic discard payload
blk-wbt: don't throttle discard or write zeroes
nbd: use dev_err_ratelimited in io path
nbd: reset the setup task for NBD_CLEAR_SOCK
nvme-fabrics: Add FC LLDD loopback driver to test FC-NVME
nvme-fabrics: Add target support for FC transport
nvme-fabrics: Add host support for FC transport
nvme-fabrics: Add FC transport LLDD api definitions
nvme-fabrics: Add FC transport FC-NVME definitions
nvme-fabrics: Add FC transport error codes to nvme.h
Add type 0x28 NVME type code to scsi fc headers
nvme-fabrics: patch target code in prep for FC transport support
nvme-fabrics: set sqe.command_id in core not transports
parser: add u64 number parser
nvme-rdma: align to generic ib_event logging helper
...
01 Nov, 2016
1 commit
-
Remove the WRITE_* and READ_SYNC wrappers, and just use the flags
directly. Where applicable this also drops usage of the
bio_set_op_attrs wrapper.Signed-off-by: Christoph Hellwig
Signed-off-by: Jens Axboe
14 Oct, 2016
2 commits
-
When any leg(s) have failed, any read will cause a new operational
default leg to be selected and the read is resubmitted to it. If that
new default leg fails the read too, no other still accessible legs are
used to resubmit the read again -- thus failing the io.Fix by allowing the read to get resubmitted until all operational legs
have been exhausted. Also, remove any details.bi_dev use as a flag.Signed-off-by: Heinz Mauelshagen
Signed-off-by: Mike Snitzer -
If a default leg has failed, any read will cause a new operational
default leg to be selected and the read is resubmitted. But until now
the read will return failure even though it was successful due to
resubmission. The reason for this is bio->bi_error was not being
cleared before resubmitting the bio.Fix by clearing bio->bi_error before resubmission.
Fixes: 4246a0b63bd8 ("block: add a bi_error field to struct bio")
Cc: stable@vger.kernel.org # 4.3+
Signed-off-by: Heinz Mauelshagen
Signed-off-by: Mike Snitzer
08 Aug, 2016
1 commit
-
Since commit 63a4cc24867d, bio->bi_rw contains flags in the lower
portion and the op code in the higher portions. This means that
old code that relies on manually setting bi_rw is most likely
going to be broken. Instead of letting that brokeness linger,
rename the member, to force old and out-of-tree code to break
at compile time instead of at runtime.No intended functional changes in this commit.
Signed-off-by: Jens Axboe
21 Jul, 2016
1 commit
-
These two are confusing leftover of the old world order, combining
values of the REQ_OP_ and REQ_ namespaces. For callers that don't
special case we mostly just replace bi_rw with bio_data_dir or
op_is_write, except for the few cases where a switch over the REQ_OP_
values makes more sense. Any check for READA is replaced with an
explicit check for REQ_RAHEAD. Also remove the READA alias for
REQ_RAHEAD.Signed-off-by: Christoph Hellwig
Reviewed-by: Johannes Thumshirn
Reviewed-by: Mike Christie
Signed-off-by: Jens Axboe
08 Jun, 2016
2 commits
-
To avoid confusion between REQ_OP_FLUSH, which is handled by
request_fn drivers, and upper layers requesting the block layer
perform a flush sequence along with possibly a WRITE, this patch
renames REQ_FLUSH to REQ_PREFLUSH.Signed-off-by: Mike Christie
Reviewed-by: Christoph Hellwig
Reviewed-by: Hannes Reinecke
Signed-off-by: Jens Axboe -
Separate the op from the rq_flag_bits and have dm
set/get the bio using bio_set_op_attrs/bio_op.Signed-off-by: Mike Christie
Reviewed-by: Hannes Reinecke
Signed-off-by: Jens Axboe
23 Feb, 2016
1 commit
-
Request-based DM will also make use of per_bio_data_size.
Signed-off-by: Mike Snitzer
03 Sep, 2015
1 commit
-
Pull device mapper update from Mike Snitzer:
- a couple small cleanups in dm-cache, dm-verity, persistent-data's
dm-btree, and DM core.- a 4.1-stable fix for dm-cache that fixes the leaking of deferred bio
prison cells- a 4.2-stable fix that adds feature reporting for the dm-stats
features added in 4.2- improve DM-snapshot to not invalidate the on-disk snapshot if
snapshot device write overflow occurs; but a write overflow triggered
through the origin device will still invalidate the snapshot.- optimize DM-thinp's async discard submission a bit now that late bio
splitting has been included in block core.- switch DM-cache's SMQ policy lock from using a mutex to a spinlock;
improves performance on very low latency devices (eg. NVMe SSD).- document DM RAID 4/5/6's discard support
[ I did not pull the slab changes, which weren't appropriate for this
tree, and weren't obviously the right thing to do anyway. At the very
least they need some discussion and explanation before getting merged.Because not pulling the actual tagged commit but doing a partial pull
instead, this merge commit thus also obviously is missing the git
signature from the original tag ]* tag 'dm-4.3-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
dm cache: fix use after freeing migrations
dm cache: small cleanups related to deferred prison cell cleanup
dm cache: fix leaking of deferred bio prison cells
dm raid: document RAID 4/5/6 discard support
dm stats: report precise_timestamps and histogram in @stats_list output
dm thin: optimize async discard submission
dm snapshot: don't invalidate on-disk image on snapshot write overflow
dm: remove unlikely() before IS_ERR()
dm: do not override error code returned from dm_get_device()
dm: test return value for DM_MAPIO_SUBMITTED
dm verity: remove unused mempool
dm cache: move wake_waker() from free_migrations() to where it is needed
dm btree remove: remove unused function get_nr_entries()
dm btree: remove unused "dm_block_t root" parameter in btree_split_sibling()
dm cache policy smq: change the mutex to a spinlock
12 Aug, 2015
1 commit
-
Some of the device mapper targets override the error code returned by
dm_get_device() and return either -EINVAL or -ENXIO. There is nothing
gained by this override. It is better to propagate the returned error
code unchanged to caller.This work was motivated by hitting an issue where the underlying device
was busy but -EINVAL was being returned. After this change we get
-EBUSY instead and it is easier to figure out the problem.Signed-off-by: Vivek Goyal
Signed-off-by: Mike Snitzer
29 Jul, 2015
1 commit
-
Currently we have two different ways to signal an I/O error on a BIO:
(1) by clearing the BIO_UPTODATE flag
(2) by returning a Linux errno value to the bi_end_io callbackThe first one has the drawback of only communicating a single possible
error (-EIO), and the second one has the drawback of not beeing persistent
when bios are queued up, and are not passed along from child to parent
bio in the ever more popular chaining scenario. Having both mechanisms
available has the additional drawback of utterly confusing driver authors
and introducing bugs where various I/O submitters only deal with one of
them, and the others have to add boilerplate code to deal with both kinds
of error returns.So add a new bi_error field to store an errno value directly in struct
bio and remove the existing mechanisms to clean all this up.Signed-off-by: Christoph Hellwig
Reviewed-by: Hannes Reinecke
Reviewed-by: NeilBrown
Signed-off-by: Jens Axboe
30 May, 2015
1 commit
-
Currently if there is a leg failure, the bio will be put into the hold
list until userspace does a remove/replace on the leg. Doing so in a
cluster config (clvmd) is problematic because there may be a temporary
path failure that results in cluster raid1 remove/replace. Such
recovery takes a long time due to a full resync.Update dm-raid1 to optionally ignore these failures so bios continue
being issued without interrupton. To enable this feature userspace
must pass "keep_log" when creating the dm-raid1 device.Signed-off-by: Lidong Zhong
Tested-by: Liuhua Wang
Acked-by: Heinz Mauelshagen
Signed-off-by: Mike Snitzer
22 May, 2015
1 commit
-
Commit c4cf5261 ("bio: skip atomic inc/dec of ->bi_remaining for
non-chains") regressed all existing callers that followed this pattern:
1) saving a bio's original bi_end_io
2) wiring up an intermediate bi_end_io
3) restoring the original bi_end_io from intermediate bi_end_io
4) calling bio_endio() to execute the restored original bi_end_ioThe regression was due to BIO_CHAIN only ever getting set if
bio_inc_remaining() is called. For the above pattern it isn't set until
step 3 above (step 2 would've needed to establish BIO_CHAIN). As such
the first bio_endio(), in step 2 above, never decremented __bi_remaining
before calling the intermediate bi_end_io -- leaving __bi_remaining with
the value 1 instead of 0. When bio_inc_remaining() occurred during step
3 it brought it to a value of 2. When the second bio_endio() was
called, in step 4 above, it should've called the original bi_end_io but
it didn't because there was an extra reference that wasn't dropped (due
to atomic operations being optimized away since BIO_CHAIN wasn't set
upfront).Fix this issue by removing the __bi_remaining management complexity for
all callers that use the above pattern -- bio_chain() is the only
interface that _needs_ to be concerned with __bi_remaining. For the
above pattern callers just expect the bi_end_io they set to get called!
Remove bio_endio_nodec() and also remove all bio_inc_remaining() calls
that aren't associated with the bio_chain() interface.Also, the bio_inc_remaining() interface has been moved local to bio.c.
Fixes: c4cf5261 ("bio: skip atomic inc/dec of ->bi_remaining for non-chains")
Reviewed-by: Christoph Hellwig
Reviewed-by: Jan Kara
Signed-off-by: Mike Snitzer
Signed-off-by: Jens Axboe
06 May, 2015
1 commit
-
Struct bio has an atomic ref count for chained bio's, and we use this
to know when to end IO on the bio. However, most bio's are not chained,
so we don't need to always introduce this atomic operation as part of
ending IO.Add a helper to elevate the bi_remaining count, and flag the bio as
now actually needing the decrement at end_io time. Rename the field
to __bi_remaining to catch any current users of this doing the
incrementing manually.For high IOPS workloads, this reduces the overhead of bio_endio()
substantially.Tested-by: Robert Elliott
Acked-by: Kent Overstreet
Reviewed-by: Jan Kara
Signed-off-by: Jens Axboe
14 Feb, 2015
1 commit
-
It may be possible that a device claims discard support but it rejects
discards with -EOPNOTSUPP. It happens when using loopback on ext2/ext3
filesystem driven by the ext4 driver. It may also happen if the
underlying devices are moved from one disk on another.If discard error happens, we reject the bio with -EOPNOTSUPP, but we do
not degrade the array.This patch fixes failed test shell/lvconvert-repair-transient.sh in the
lvm2 testsuite if the testsuite is extracted on an ext2 or ext3
filesystem and it is being driven by the ext4 driver.Signed-off-by: Mikulas Patocka
Signed-off-by: Mike Snitzer
Cc: stable@vger.kernel.org
18 Feb, 2014
1 commit
-
When restoring bi_end_io, increase bi_remaining before retrying the bio
to avoid BUG_ON(atomic_read(&bio->bi_remaining)
Signed-off-by: Mike Snitzer
24 Nov, 2013
2 commits
-
Now that we've got a mechanism for immutable biovecs -
bi_iter.bi_bvec_done - we need to convert drivers to use primitives that
respect it instead of using the bvec array directly.Signed-off-by: Kent Overstreet
Cc: Jens Axboe
Cc: NeilBrown
Cc: Alasdair Kergon
Cc: dm-devel@redhat.com -
Immutable biovecs are going to require an explicit iterator. To
implement immutable bvecs, a later patch is going to add a bi_bvec_done
member to this struct; for now, this patch effectively just renames
things.Signed-off-by: Kent Overstreet
Cc: Jens Axboe
Cc: Geert Uytterhoeven
Cc: Benjamin Herrenschmidt
Cc: Paul Mackerras
Cc: "Ed L. Cashin"
Cc: Nick Piggin
Cc: Lars Ellenberg
Cc: Jiri Kosina
Cc: Matthew Wilcox
Cc: Geoff Levand
Cc: Yehuda Sadeh
Cc: Sage Weil
Cc: Alex Elder
Cc: ceph-devel@vger.kernel.org
Cc: Joshua Morris
Cc: Philip Kelleher
Cc: Rusty Russell
Cc: "Michael S. Tsirkin"
Cc: Konrad Rzeszutek Wilk
Cc: Jeremy Fitzhardinge
Cc: Neil Brown
Cc: Alasdair Kergon
Cc: Mike Snitzer
Cc: dm-devel@redhat.com
Cc: Martin Schwidefsky
Cc: Heiko Carstens
Cc: linux390@de.ibm.com
Cc: Boaz Harrosh
Cc: Benny Halevy
Cc: "James E.J. Bottomley"
Cc: Greg Kroah-Hartman
Cc: "Nicholas A. Bellinger"
Cc: Alexander Viro
Cc: Chris Mason
Cc: "Theodore Ts'o"
Cc: Andreas Dilger
Cc: Jaegeuk Kim
Cc: Steven Whitehouse
Cc: Dave Kleikamp
Cc: Joern Engel
Cc: Prasad Joshi
Cc: Trond Myklebust
Cc: KONISHI Ryusuke
Cc: Mark Fasheh
Cc: Joel Becker
Cc: Ben Myers
Cc: xfs@oss.sgi.com
Cc: Steven Rostedt
Cc: Frederic Weisbecker
Cc: Ingo Molnar
Cc: Len Brown
Cc: Pavel Machek
Cc: "Rafael J. Wysocki"
Cc: Herton Ronaldo Krzesinski
Cc: Ben Hutchings
Cc: Andrew Morton
Cc: Guo Chao
Cc: Tejun Heo
Cc: Asai Thambi S P
Cc: Selvan Mani
Cc: Sam Bradshaw
Cc: Wei Yongjun
Cc: "Roger Pau Monné"
Cc: Jan Beulich
Cc: Stefano Stabellini
Cc: Ian Campbell
Cc: Sebastian Ott
Cc: Christian Borntraeger
Cc: Minchan Kim
Cc: Jiang Liu
Cc: Nitin Gupta
Cc: Jerome Marchand
Cc: Joe Perches
Cc: Peng Tao
Cc: Andy Adamson
Cc: fanchaoting
Cc: Jie Liu
Cc: Sunil Mushran
Cc: "Martin K. Petersen"
Cc: Namjae Jeon
Cc: Pankaj Kumar
Cc: Dan Magenheimer
Cc: Mel Gorman 6
23 Aug, 2013
1 commit
-
dbf2576e37 ("workqueue: make all workqueues non-reentrant") made
WQ_NON_REENTRANT no-op and the flag is going away. Remove its usages.This patch doesn't introduce any behavior changes.
Signed-off-by: Tejun Heo
Signed-off-by: Mike Snitzer
Signed-off-by: Alasdair G Kergon
Acked-by: Joe Thornber
24 Mar, 2013
1 commit
-
Bunch of places in the code weren't using it where they could be -
this'll reduce the size of the patch that puts bi_sector/bi_size/bi_idx
into a struct bvec_iter.Signed-off-by: Kent Overstreet
CC: Jens Axboe
CC: "Ed L. Cashin"
CC: Nick Piggin
CC: Jiri Kosina
CC: Jim Paris
CC: Geoff Levand
CC: Alasdair Kergon
CC: dm-devel@redhat.com
CC: Neil Brown
CC: Steven Rostedt
Acked-by: Ed Cashin
02 Mar, 2013
3 commits
-
This patch allows the administrator to reduce the rate at which kcopyd
issues I/O.Each module that uses kcopyd acquires a throttle parameter that can be
set in /sys/module/*/parameters.We maintain a history of kcopyd usage by each module in the variables
io_period and total_period in struct dm_kcopyd_throttle. The actual
kcopyd activity is calculated as a percentage of time equal to
"(100 * io_period / total_period)". This is compared with the user-defined
throttle percentage threshold and if it is exceeded, we sleep.Signed-off-by: Mikulas Patocka
Signed-off-by: Alasdair G Kergon -
Use 'bio' in the name of variables and functions that deal with
bios rather than 'request' to avoid confusion with the normal
block layer use of 'request'.No functional changes.
Signed-off-by: Alasdair G Kergon
-
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
Signed-off-by: Alasdair G Kergon
22 Dec, 2012
6 commits
-
This patch removes map_info from bio-based device mapper targets.
map_info is still used for request-based targets.Signed-off-by: Mikulas Patocka
Signed-off-by: Alasdair G Kergon -
Don't use map_info any more in dm-raid1.
map_info was used for writes to hold the region number. For this purpose
we add a new field dm_bio_details to dm_raid1_bio_record.map_info was used for reads to hold a pointer to dm_raid1_bio_record (if
the pointer was non-NULL, bio details were saved; if the pointer was
NULL, bio details were not saved). We use
dm_raid1_bio_record.details->bi_bdev for this purpose. If bi_bdev is
NULL, details were not saved, if bi_bdev is non-NULL, details were
saved.Signed-off-by: Mikulas Patocka
Signed-off-by: Alasdair G Kergon -
Rename struct read_record to bio_record in dm-raid1.
In the following patch, the structure will be used for both read and
write bios, so rename it.Signed-off-by: Mikulas Patocka
Signed-off-by: Alasdair G Kergon -
Replace read_record_pool with per_bio_data in dm-raid1.
Signed-off-by: Mikulas Patocka
Signed-off-by: Alasdair G Kergon -
Use a defined macro DM_ENDIO_INCOMPLETE instead of a numeric constant.
Signed-off-by: Mikulas Patocka
Signed-off-by: Alasdair G Kergon -
mempool_alloc can't fail if __GFP_WAIT is specified, so the condition
that tests if read_record is non-NULL is always true.Signed-off-by: Mikulas Patocka
Signed-off-by: Alasdair G Kergon