In recovery mode, we don't:
- replay the journal
- check checksums
- allow writes to the device
This mode can be used as a last resort for data recovery. The
motivation for recovery mode is that when there is a single error in the
journal, the user should not lose access to the whole device.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Add optional "sector_size" parameter that specifies encryption sector
size (atomic unit of block device encryption).
Parameter can be in range 512 - 4096 bytes and must be power of two.
For compatibility reasons, the maximal IO must fit into the page limit,
so the limit is set to the minimal page size possible (4096 bytes).
NOTE: this device cannot yet be handled by cryptsetup if this parameter
is set.
IV for the sector is calculated from the 512 bytes sector offset unless
the iv_large_sectors option is used.
Test script using dmsetup:
DEV="/dev/sdb"
DEV_SIZE=$(blockdev --getsz $DEV)
KEY="9c1185a5c5e9fc54612808977ee8f548b2258d31ddadef707ba62c166051b9e3cd0294c27515f2bccee924e8823ca6e124b8fc3167ed478bca702babe4e130ac"
BLOCK_SIZE=4096
# dmsetup create test_crypt --table "0 $DEV_SIZE crypt aes-xts-plain64 $KEY 0 $DEV 0 1 sector_size:$BLOCK_SIZE"
# dmsetup table --showkeys test_crypt
Signed-off-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
For the new authenticated encryption we have to support generic composed
modes (combination of encryption algorithm and authenticator) because
this is how the kernel crypto API accesses such algorithms.
To simplify the interface, we accept an algorithm directly in crypto API
format. The new format is recognised by the "capi:" prefix. The
dmcrypt internal IV specification is the same as for the old format.
The crypto API cipher specifications format is:
capi:cipher_api_spec-ivmode[:ivopts]
Examples:
capi:cbc(aes)-essiv:sha256 (equivalent to old aes-cbc-essiv:sha256)
capi:xts(aes)-plain64 (equivalent to old aes-xts-plain64)
Examples of authenticated modes:
capi:gcm(aes)-random
capi:authenc(hmac(sha256),xts(aes))-random
capi:rfc7539(chacha20,poly1305)-random
Authenticated modes can only be configured using the new cipher format.
Note that this format allows user to specify arbitrary combinations that
can be insecure. (Policy decision is done in cryptsetup userspace.)
Authenticated encryption algorithms can be of two types, either native
modes (like GCM) that performs both encryption and authentication
internally, or composed modes where user can compose AEAD with separate
specification of encryption algorithm and authenticator.
For composed mode with HMAC (length-preserving encryption mode like an
XTS and HMAC as an authenticator) we have to calculate HMAC digest size
(the separate authentication key is the same size as the HMAC digest).
Introduce crypt_ctr_auth_cipher() to parse the crypto API string to get
HMAC algorithm and retrieve digest size from it.
Also, for HMAC composed mode we need to parse the crypto API string to
get the cipher mode nested in the specification. For native AEAD mode
(like GCM), we can use crypto_tfm_alg_name() API to get the cipher
specification.
Because the HMAC composed mode is not processed the same as the native
AEAD mode, the CRYPT_MODE_INTEGRITY_HMAC flag is no longer needed and
"hmac" specification for the table integrity argument is removed.
Signed-off-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Allow the use of per-sector metadata, provided by the dm-integrity
module, for integrity protection and persistently stored per-sector
Initialization Vector (IV). The underlying device must support the
"DM-DIF-EXT-TAG" dm-integrity profile.
The per-bio integrity metadata is allocated by dm-crypt for every bio.
Example of low-level mapping table for various types of use:
DEV=/dev/sdb
SIZE=417792
# Additional HMAC with CBC-ESSIV, key is concatenated encryption key + HMAC key
SIZE_INT=389952
dmsetup create x --table "0 $SIZE_INT integrity $DEV 0 32 J 0"
dmsetup create y --table "0 $SIZE_INT crypt aes-cbc-essiv:sha256 \
11ff33c6fb942655efb3e30cf4c0fd95f5ef483afca72166c530ae26151dd83b \
00112233445566778899aabbccddeeff00112233445566778899aabbccddeeff \
0 /dev/mapper/x 0 1 integrity:32:hmac(sha256)"
# AEAD (Authenticated Encryption with Additional Data) - GCM with random IVs
# GCM in kernel uses 96bits IV and we store 128bits auth tag (so 28 bytes metadata space)
SIZE_INT=393024
dmsetup create x --table "0 $SIZE_INT integrity $DEV 0 28 J 0"
dmsetup create y --table "0 $SIZE_INT crypt aes-gcm-random \
11ff33c6fb942655efb3e30cf4c0fd95f5ef483afca72166c530ae26151dd83b \
0 /dev/mapper/x 0 1 integrity:28:aead"
# Random IV only for XTS mode (no integrity protection but provides atomic random sector change)
SIZE_INT=401272
dmsetup create x --table "0 $SIZE_INT integrity $DEV 0 16 J 0"
dmsetup create y --table "0 $SIZE_INT crypt aes-xts-random \
11ff33c6fb942655efb3e30cf4c0fd95f5ef483afca72166c530ae26151dd83b \
0 /dev/mapper/x 0 1 integrity:16:none"
# Random IV with XTS + HMAC integrity protection
SIZE_INT=377656
dmsetup create x --table "0 $SIZE_INT integrity $DEV 0 48 J 0"
dmsetup create y --table "0 $SIZE_INT crypt aes-xts-random \
11ff33c6fb942655efb3e30cf4c0fd95f5ef483afca72166c530ae26151dd83b \
00112233445566778899aabbccddeeff00112233445566778899aabbccddeeff \
0 /dev/mapper/x 0 1 integrity:48:hmac(sha256)"
Both AEAD and HMAC protection authenticates not only data but also
sector metadata.
HMAC protection is implemented through autenc wrapper (so it is
processed the same way as an authenticated mode).
In HMAC mode there are two keys (concatenated in dm-crypt mapping
table). First is the encryption key and the second is the key for
authentication (HMAC). (It is userspace decision if these keys are
independent or somehow derived.)
The sector request for AEAD/HMAC authenticated encryption looks like this:
|----- AAD -------|------ DATA -------|-- AUTH TAG --|
| (authenticated) | (auth+encryption) | |
| sector_LE | IV | sector in/out | tag in/out |
For writes, the integrity fields are calculated during AEAD encryption
of every sector and stored in bio integrity fields and sent to
underlying dm-integrity target for storage.
For reads, the integrity metadata is verified during AEAD decryption of
every sector (they are filled in by dm-integrity, but the integrity
fields are pre-allocated in dm-crypt).
There is also an experimental support in cryptsetup utility for more
friendly configuration (part of LUKS2 format).
Because the integrity fields are not valid on initial creation, the
device must be "formatted". This can be done by direct-io writes to the
device (e.g. dd in direct-io mode). For now, there is available trivial
tool to do this, see: https://github.com/mbroz/dm_int_tools
Signed-off-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Ondrej Mosnacek <omosnacek@gmail.com>
Signed-off-by: Vashek Matyas <matyas@fi.muni.cz>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The dm-integrity target emulates a block device that has additional
per-sector tags that can be used for storing integrity information.
A general problem with storing integrity tags with every sector is that
writing the sector and the integrity tag must be atomic - i.e. in case of
crash, either both sector and integrity tag or none of them is written.
To guarantee write atomicity the dm-integrity target uses a journal. It
writes sector data and integrity tags into a journal, commits the journal
and then copies the data and integrity tags to their respective location.
The dm-integrity target can be used with the dm-crypt target - in this
situation the dm-crypt target creates the integrity data and passes them
to the dm-integrity target via bio_integrity_payload attached to the bio.
In this mode, the dm-crypt and dm-integrity targets provide authenticated
disk encryption - if the attacker modifies the encrypted device, an I/O
error is returned instead of random data.
The dm-integrity target can also be used as a standalone target, in this
mode it calculates and verifies the integrity tag internally. In this
mode, the dm-integrity target can be used to detect silent data
corruption on the disk or in the I/O path.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Fix typos and add the following to the scripts/spelling.txt:
explictely||explicitly
Link: http://lkml.kernel.org/r/1481573103-11329-25-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If "metadata2" is provided as a table argument when creating/loading a
cache target a more compact metadata format, with separate dirty bits,
is used. "metadata2" improves speed of shutting down a cache target.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Add md raid4/5/6 journaling support (upstream commit bac624f3f8 started
the implementation) which closes the write hole (i.e. non-atomic updates
to stripes) using a dedicated journal device.
Background:
raid4/5/6 stripes hold N data payloads per stripe plus one parity raid4/5
or two raid6 P/Q syndrome payloads in an in-memory stripe cache.
Parity or P/Q syndromes used to recover any data payloads in case of a disk
failure are calculated from the N data payloads and need to be updated on the
different component devices of the raid device. Those are non-atomic,
persistent updates. Hence a crash can cause failure to update all stripe
payloads persistently and thus cause data loss during stripe recovery.
This problem gets addressed by writing whole stripe cache entries (together with
journal metadata) to a persistent journal entry on a dedicated journal device.
Only if that journal entry is written successfully, the stripe cache entry is
updated on the component devices of the raid device (i.e. writethrough type).
In case of a crash, the entry can be recovered from the journal and be written
again thus ensuring consistent stripe payload suitable to data recovery.
Future dependencies:
once writeback caching being worked on to compensate for the throughput
implictions involved with writethrough overhead is supported with journaling
in upstream, an additional patch based on this one will support it in dm-raid.
Journal resilience related remarks:
because stripes are recovered from the journal in case of a crash, the
journal device better be resilient. Resilience becomes mandatory with
future writeback support, because loosing the working set in the log
means data loss as oposed to writethrough, were the loss of the
journal device 'only' reintroduces the write hole.
Fix comment on data offsets in parse_dev_params() and initialize
new_data_offset as well.
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This fix addresses the following 3 failure scenarios:
1) If a (transiently) inaccessible metadata device is being passed into the
constructor (e.g. a device tuple '254:4 254:5'), it is processed as if
'- -' was given. This erroneously results in a status table line containing
'- -', which mistakenly differs from what has been passed in. As a result,
userspace libdevmapper puts the device tuple seperate from the RAID device
thus not processing the dependencies properly.
2) False health status char 'A' instead of 'D' is emitted on the status
status info line for the meta/data device tuple in this metadata device
failure case.
3) If the metadata device is accessible when passed into the constructor
but the data device (partially) isn't, that leg may be set faulty by the
raid personality on access to the (partially) unavailable leg. Restore
tried in a second raid device resume on such failed leg (status char 'D')
fails after the (partial) leg returned.
Fixes for aforementioned failure scenarios:
- don't release passed in devices in the constructor thus allowing the
status table line to e.g. contain '254:4 254:5' rather than '- -'
- emit device status char 'D' rather than 'A' for the device tuple
with the failed metadata device on the status info line
- when attempting to restore faulty devices in a second resume, allow the
device hot remove function to succeed by setting the device to not in-sync
In case userspace intentionally passes '- -' into the constructor to avoid that
device tuple (e.g. to split off a raid1 leg temporarily for later re-addition),
the status table line will correctly show '- -' and the status info line will
provide a '-' device health character for the non-defined device tuple.
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
According to `man blockdev':
--getsize
Print device size (32-bit!) in sectors.
Deprecated in favor of the --getsz option.
...
--getsz
Get size in 512-byte sectors.
Hence, occurrences of `--getsize' should be replaced with `--getsz',
which this commit has achieved as follows:
$ cd "$repo"
$ git grep -l -e --getsz
Documentation/device-mapper/delay.txt
Documentation/device-mapper/dm-crypt.txt
Documentation/device-mapper/linear.txt
Documentation/device-mapper/log-writes.txt
Documentation/device-mapper/striped.txt
Documentation/device-mapper/switch.txt
$ cd Documentation/device-mapper
$ sed -i s/getsize/getsz/g *
Signed-off-by: Michael Witten <mfwitten@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
The kernel key service is a generic way to store keys for the use of
other subsystems. Currently there is no way to use kernel keys in dm-crypt.
This patch aims to fix that. Instead of key userspace may pass a key
description with preceding ':'. So message that constructs encryption
mapping now looks like this:
<cipher> [<key>|:<key_string>] <iv_offset> <dev_path> <start> [<#opt_params> <opt_params>]
where <key_string> is in format: <key_size>:<key_type>:<key_description>
Currently we only support two elementary key types: 'user' and 'logon'.
Keys may be loaded in dm-crypt either via <key_string> or using
classical method and pass the key in hex representation directly.
dm-crypt device initialised with a key passed in hex representation may be
replaced with key passed in key_string format and vice versa.
(Based on original work by Andrey Ryabinin)
Signed-off-by: Ondrej Kozina <okozina@redhat.com>
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
dm-raid 1.9.0 fails to activate existing RAID4/10 devices that have the
old superblock format (which does not have takeover/reshaping support
that was added via commit 33e53f0685).
Fix validation path for old superblocks by reverting to the old raid4
layout and basing checks on mddev->new_{level,layout,...} members in
super_init_validation().
Cc: stable@vger.kernel.org # 4.8
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Since commit 63a4cc2486, 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 <axboe@fb.com>
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 <mchristi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
smq seems to be performing better than the old mq policy in all
situations, as well as using a quarter of the memory.
Make 'mq' an alias for 'smq' when choosing a cache policy. The tunables
that were present for the old mq are faked, and have no effect. mq
should be considered deprecated now.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
If ignore_zero_blocks is enabled dm-verity will return zeroes for blocks
matching a zero hash without validating the content.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Add support for correcting corrupted blocks using Reed-Solomon.
This code uses RS(255, N) interleaved across data and hash
blocks. Each error-correcting block covers N bytes evenly
distributed across the combined total data, so that each byte is a
maximum distance away from the others. This makes it possible to
recover from several consecutive corrupted blocks with relatively
small space overhead.
In addition, using verity hashes to locate erasures nearly doubles
the effectiveness of error correction. Being able to detect
corrupted blocks also improves performance, because only corrupted
blocks need to corrected.
For a 2 GiB partition, RS(255, 253) (two parity bytes for each
253-byte block) can correct up to 16 MiB of consecutive corrupted
blocks if erasures can be located, and 8 MiB if they cannot, with
16 MiB space overhead.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
users (e.g. kvm guests) that issued ioctls when a multipath device had
no available paths.
- Include Christoph's refactoring of DM's ioctl handling and add support
for passing through persistent reservations with DM multipath.
- All other changes are very simple cleanups.
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Merge tag 'dm-4.4-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device mapper updates from Mike Snitzer:
"Smaller set of DM changes for this merge. I've based these changes on
Jens' for-4.4/reservations branch because the associated DM changes
required it.
- Revert a dm-multipath change that caused a regression for
unprivledged users (e.g. kvm guests) that issued ioctls when a
multipath device had no available paths.
- Include Christoph's refactoring of DM's ioctl handling and add
support for passing through persistent reservations with DM
multipath.
- All other changes are very simple cleanups"
* tag 'dm-4.4-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
dm switch: simplify conditional in alloc_region_table()
dm delay: document that offsets are specified in sectors
dm delay: capitalize the start of an delay_ctr() error message
dm delay: Use DM_MAPIO macros instead of open-coded equivalents
dm linear: remove redundant target name from error messages
dm persistent data: eliminate unnecessary return values
dm: eliminate unused "bioset" process for each bio-based DM device
dm: convert ffs to __ffs
dm: drop NULL test before kmem_cache_destroy() and mempool_destroy()
dm: add support for passing through persistent reservations
dm: refactor ioctl handling
Revert "dm mpath: fix stalls when handling invalid ioctls"
dm: initialize non-blk-mq queue data before queue is used
Only delay params are mentioned in delay.txt.
Mention offsets just like documents for linear and flakey do.
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Commit 76c44f6d80 introduced the possibly for "Overflow" to be reported
by the snapshot device's status. Older userspace (e.g. lvm2) does not
handle the "Overflow" status response.
Fix this incompatibility by requiring newer userspace code, that can
cope with "Overflow", request the persistent store with overflow support
by using "PO" (Persistent with Overflow) for the snapshot store type.
Reported-by: Zdenek Kabelac <zkabelac@redhat.com>
Fixes: 76c44f6d80 ("dm snapshot: don't invalidate on-disk image on snapshot write overflow")
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
For RAID 4/5/6 data integrity reasons 'discard_zeroes_data' must work
properly.
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
If the user selected the precise_timestamps or histogram options, report
it in the @stats_list message output.
If the user didn't select these options, no extra tokens are reported,
thus it is backward compatible with old software that doesn't know about
precise timestamps and histogram.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 4.2
There is currently no way to see that the needs_check flag has been set
in the metadata. Display 'needs_check' in the cache status if it is set
in the cache metadata.
Also, update cache documentation.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
There is currently no way to see that the needs_check flag has been set
in the metadata. Display 'needs_check' in the thin-pool status if it is
set in the thinp metadata.
Also, update thinp documentation.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Add an option to dm statistics to collect and report a histogram of
IO latencies.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Make it possible to use precise timestamps with nanosecond granularity
in dm statistics.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The Stochastic multiqueue (SMQ) policy (vs MQ) offers the promise of
less memory utilization, improved performance and increased adaptability
in the face of changing workloads. SMQ also does not have any
cumbersome tuning knobs.
Users may switch from "mq" to "smq" simply by appropriately reloading a
DM table that is using the cache target. Doing so will cause all of the
mq policy's hints to be dropped. Also, performance of the cache may
degrade slightly until smq recalculates the origin device's hotspots
that should be cached.
In the future the "mq" policy will just silently make use of "smq" and
the mq code will be removed.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
If a cache metadata operation fails (e.g. transaction commit) the
cache's metadata device will abort the current transaction, set a new
needs_check flag, and the cache will transition to "read-only" mode. If
aborting the transaction or setting the needs_check flag fails the cache
will transition to "fail-io" mode.
Once needs_check is set the cache device will not be allowed to
activate. Activation requires write access to metadata. Future work is
needed to add proper support for running the cache in read-only mode.
Once in fail-io mode the cache will report a status of "Fail".
Also, add commit() wrapper that will disallow commits if in read_only or
fail mode.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Add dm-raid access to the MD RAID0 personality to enable single zone
striping.
The following changes enable that access:
- add type definition to raid_types array
- make bitmap creation conditonal in super_validate(), because
bitmaps are not allowed in raid0
- set rdev->sectors to the data image size in super_validate()
to allow the raid0 personality to calculate the MD array
size properly
- use mdddev(un)lock() functions instead of direct mutex_(un)lock()
(wrapped in here because it's a trivial change)
- enhance raid_status() to always report full sync for raid0
so that userspace checks for 100% sync will succeed and allow
for resize (and takeover/reshape once added in future paches)
- enhance raid_resume() to not load bitmap in case of raid0
- add merge function to avoid data corruption (seen with readahead)
that resulted from bio payloads that grew too large. This problem
did not occur with the other raid levels because it either did not
apply without striping (raid1) or was avoided via stripe caching.
- raise version to 1.7.0 because of the raid0 API change
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Reviewed-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Remove comment above parse_raid_params() that claims
"devices_handle_discard_safely" is a table line argument when it is
actually is a module parameter.
Also, backfill dm-raid target version 1.6.0 documentation.
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Reviewed-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cryptsetup home page moved to GitLab.
Also remove link to abandonded Truecrypt page.
Signed-off-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Introduce a new target that is meant for file system developers to test file
system integrity at particular points in the life of a file system. We capture
all write requests and associated data and log them to a separate device
for later replay. There is a userspace utility to do this replay. The
idea behind this is to give file system developers a tool to verify that
the file system is always consistent.
Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Zach Brown <zab@zabbo.net>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Add device specific modes to dm-verity to specify how corrupted
blocks should be handled. The following modes are defined:
- DM_VERITY_MODE_EIO is the default behavior, where reading a
corrupted block results in -EIO.
- DM_VERITY_MODE_LOGGING only logs corrupted blocks, but does
not block the read.
- DM_VERITY_MODE_RESTART calls kernel_restart when a corrupted
block is discovered.
In addition, each mode sends a uevent to notify userspace of
corruption and to allow further recovery actions.
The driver defaults to previous behavior (DM_VERITY_MODE_EIO)
and other modes can be enabled with an additional parameter to
the verity table.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Make it possible to disable offloading writes by setting the optional
'submit_from_crypt_cpus' table argument.
There are some situations where offloading write bios from the
encryption threads to a single thread degrades performance
significantly.
The default is to offload write bios to the same thread because it
benefits CFQ to have writes submitted using the same IO context.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Use unbound workqueue by default so that work is automatically balanced
between available CPUs. The original behavior of encrypting using the
same cpu that IO was submitted on can still be enabled by setting the
optional 'same_cpu_crypt' table argument.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Before, if the user wanted sequential IO to be promoted to the cache
they'd have to set sequential_threshold to some nebulous large value.
Now, the user may easily disable sequential IO detection (and sequential
IO's implicit bypass of the cache) by setting sequential_threshold to 0.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Rather than maintaining a separate promote_threshold variable that we
periodically update we now use the hit count of the oldest clean
block. Also add a fudge factor to discourage demoting dirty blocks.
With some tests this has a sizeable difference, because the old code
was too eager to demote blocks. For example, device-mapper-test-suite's
git_extract_cache_quick test goes from taking 190 seconds, to 142
(linear on spindle takes 250).
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Add support for quickly loading a repetitive pattern into the
dm-switch target.
In the "set_regions_mappings" message, the user may now use "Rn,m" as
one of the arguments. "n" and "m" are hexadecimal numbers. The "Rn,m"
argument repeats the last "n" arguments in the following "m" slots.
For example:
dmsetup message switch 0 set_region_mappings 1000:1 :2 R2,10
is equivalent to
dmsetup message switch 0 set_region_mappings 1000:1 :2 :1 :2 :1 :2 :1 :2 \
:1 :2 :1 :2 :1 :2 :1 :2 :1 :2
Requested-by: Jay Wang <jwang@nimblestorage.com>
Tested-by: Jay Wang <jwang@nimblestorage.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Commit 85ad643b ("dm thin: add timeout to stop out-of-data-space mode
holding IO forever") introduced a fixed 60 second timeout. Users may
want to either disable or modify this timeout.
Allow the out-of-data-space timeout to be configured using the
'no_space_timeout' dm-thin-pool module param. Setting it to 0 will
disable the timeout, resulting in IO being queued until more data space
is added to the thin-pool.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.14+
dm-era is a target that behaves similar to the linear target. In
addition it keeps track of which blocks were written within a user
defined period of time called an 'era'. Each era target instance
maintains the current era as a monotonically increasing 32-bit
counter.
Use cases include tracking changed blocks for backup software, and
partially invalidating the contents of a cache to restore cache
coherency after rolling back a vendor snapshot.
dm-era is primarily expected to be paired with the dm-cache target.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The Documentation for the thin provisioning target's held metadata root
feature was incorrect. It is now available and the value for the held
metadata root is in block units (not 512b sectors).
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
If a thin metadata operation fails the current transaction will abort,
whereby causing potential for IO layers up the stack (e.g. filesystems)
to have data loss. As such, set THIN_METADATA_NEEDS_CHECK_FLAG in the
thin metadata's superblock which:
1) requires the user verify the thin metadata is consistent (e.g. use
thin_check, etc)
2) suggests the user verify the thin data is consistent (e.g. use fsck)
The only way to clear the superblock's THIN_METADATA_NEEDS_CHECK_FLAG is
to run thin_repair.
On metadata operation failure: abort current metadata transaction, set
pool in read-only mode, and now set the needs_check flag.
As part of this change, constraints are introduced or relaxed:
* don't allow a pool to transition to write mode if needs_check is set
* don't allow data or metadata space to be resized if needs_check is set
* if a thin pool's metadata space is exhausted: the kernel will now
force the user to take the pool offline for repair before the kernel
will allow the metadata space to be extended.
Also, update Documentation to include information about when the thin
provisioning target commits metadata, how it handles metadata failures
and running out of space.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
