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>
The cache's policy may have been established using the "default" alias,
which is currently the "mq" policy but the default policy may change in
the future. It is useful to know exactly which policy is being used.
Add a 'real' member to the dm_cache_policy_type structure and have the
"default" dm_cache_policy_type point to the real "mq"
dm_cache_policy_type. Update dm_cache_policy_get_name() to check if
real is set, if so report the name of the real policy (not the alias).
Requested-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Improve cache_status to emit:
<metadata block size> <#used metadata blocks>/<#total metadata blocks>
<cache block size> <#used cache blocks>/<#total cache blocks>
...
Adding the block sizes allows for easier calculation of the overall size
of both the metadata and cache devices. Adding <#total cache blocks>
provides useful context for how much of the cache is used.
Unfortunately these additions to the status will require updates to
users' scripts that monitor the cache status. But these changes help
provide more comprehensive information about the cache device and will
simplify tools that are being developed to manage dm-cache devices --
because they won't need to issue 3 operations to cobble together the
information that we can easily provide via a single status ioctl.
While updating the status documentation in cache.txt spaces were
tabify'd.
Requested-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Internally the mq policy maintains a promotion threshold variable. If
the hit count of a block not in the cache goes above this threshold it
gets promoted to the cache.
This patch introduces three new tunables that allow you to tweak the
promotion threshold by adding a small value. These adjustments depend
on the io type:
read_promote_adjustment: READ io, default 4
write_promote_adjustment: WRITE io, default 8
discard_promote_adjustment: READ/WRITE io to a discarded block, default 1
If you're trying to quickly warm a new cache device you may wish to
reduce these to encourage promotion. Remember to switch them back to
their defaults after the cache fills though.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
If the pool runs out of data or metadata space, the pool can either
queue or error the IO destined to the data device. The default is to
queue the IO until more space is added.
An admin may now configure the pool to error IO when no space is
available by setting the 'error_if_no_space' feature when loading the
thin-pool table.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
The cache target's invalidate_cblocks message allows cache block
(cblock) ranges to be expressed with: <cblock start>-<cblock end>
The range's <cblock end> value is "one past the end", so the range
includes <cblock start> through <cblock end>-1.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Document passthrough mode, cache shrinking, and cache invalidation.
Also, use strcasecmp() and hlist_unhashed().
Reported-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cache block invalidation is removing an entry from the cache without
writing it back. Cache blocks can be invalidated via the
'invalidate_cblocks' message, which takes an arbitrary number of cblock
ranges:
invalidate_cblocks [<cblock>|<cblock begin>-<cblock end>]*
E.g.
dmsetup message my_cache 0 invalidate_cblocks 2345 3456-4567 5678-6789
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
"Passthrough" is a dm-cache operating mode (like writethrough or
writeback) which is intended to be used when the cache contents are not
known to be coherent with the origin device. It behaves as follows:
* All reads are served from the origin device (all reads miss the cache)
* All writes are forwarded to the origin device; additionally, write
hits cause cache block invalidates
This mode decouples cache coherency checks from cache device creation,
largely to avoid having to perform coherency checks while booting. Boot
scripts can create cache devices in passthrough mode and put them into
service (mount cached filesystems, for example) without having to worry
about coherency. Coherency that exists is maintained, although the
cache will gradually cool as writes take place.
Later, applications can perform coherency checks, the nature of which
will depend on the type of the underlying storage. If coherency can be
verified, the cache device can be transitioned to writethrough or
writeback mode while still warm; otherwise, the cache contents can be
discarded prior to transitioning to the desired operating mode.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Morgan Mears <Morgan.Mears@netapp.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
There are now two multiqueues for in cache blocks. A clean one and a
dirty one.
writeback_work comes from the dirty one. Demotions come from the clean
one.
There are two benefits:
- Performance improvement, since demoting a clean block is a noop.
- The cache cleans itself when io load is light.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
dm-crypt can already activate TCRYPT (TrueCrypt compatible) containers
in LRW or XTS block encryption mode.
TCRYPT containers prior to version 4.1 use CBC mode with some additional
tweaks, this patch adds support for these containers.
This new mode is implemented using special IV generator named TCW
(TrueCrypt IV with whitening). TCW IV only supports containers that are
encrypted with one cipher (Tested with AES, Twofish, Serpent, CAST5 and
TripleDES).
While this mode is legacy and is known to be vulnerable to some
watermarking attacks (e.g. revealing of hidden disk existence) it can
still be useful to activate old containers without using 3rd party
software or for independent forensic analysis of such containers.
(Both the userspace and kernel code is an independent implementation
based on the format documentation and it completely avoids use of
original source code.)
The TCW IV generator uses two additional keys: Kw (whitening seed, size
is always 16 bytes - TCW_WHITENING_SIZE) and Kiv (IV seed, size is
always the IV size of the selected cipher). These keys are concatenated
at the end of the main encryption key provided in mapping table.
While whitening is completely independent from IV, it is implemented
inside IV generator for simplification.
The whitening value is always 16 bytes long and is calculated per sector
from provided Kw as initial seed, xored with sector number and mixed
with CRC32 algorithm. Resulting value is xored with ciphertext sector
content.
IV is calculated from the provided Kiv as initial IV seed and xored with
sector number.
Detailed calculation can be found in the Truecrypt documentation for
version < 4.1 and will also be described on dm-crypt site, see:
http://code.google.com/p/cryptsetup/wiki/DMCrypt
The experimental support for activation of these containers is already
present in git devel brach of cryptsetup.
Signed-off-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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>
Inform users that the data block size can't be any arbitrary number,
i.e. its value must be between 64KB and 1GB. Also, it should be a
multiple of 64KB.
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Place upper bound on the cache's data block size (1GB).
Inform users that the data block size can't be any arbitrary number,
i.e. its value must be between 32KB and 1GB. Also, it should be a
multiple of 32KB.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
A cache's metadata device may not be shared by multiple cache devices.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Pull device-mapper changes from Alasdair G Kergon:
"Add a device-mapper target called dm-switch to provide a multipath
framework for storage arrays that dynamically reconfigure their
preferred paths for different device regions.
Fix a bug in the verity target that prevented its use with some
specific sizes of devices.
Improve some locking mechanisms in the device-mapper core and bufio.
Add Mike Snitzer as a device-mapper maintainer.
A few more clean-ups and fixes"
* tag 'dm-3.11-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm:
dm: add switch target
dm: update maintainers
dm: optimize reorder structure
dm: optimize use SRCU and RCU
dm bufio: submit writes outside lock
dm cache: fix arm link errors with inline
dm verity: use __ffs and __fls
dm flakey: correct ctr alloc failure mesg
dm verity: remove pointless comparison
dm: use __GFP_HIGHMEM in __vmalloc
dm verity: fix inability to use a few specific devices sizes
dm ioctl: set noio flag to avoid __vmalloc deadlock
dm mpath: fix ioctl deadlock when no paths
dm-switch is a new target that maps IO to underlying block devices
efficiently when there is a large number of fixed-sized address regions
but there is no simple pattern to allow for a compact mapping
representation such as dm-stripe.
Though we have developed this target for a specific storage device, Dell
EqualLogic, we have made an effort to keep it as general purpose as
possible in the hope that others may benefit.
Originally developed by Jim Ramsay. Simplified by Mikulas Patocka.
Signed-off-by: Jim Ramsay <jim_ramsay@dell.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Pull trivial tree updates from Jiri Kosina:
"The usual stuff from trivial tree"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (34 commits)
treewide: relase -> release
Documentation/cgroups/memory.txt: fix stat file documentation
sysctl/net.txt: delete reference to obsolete 2.4.x kernel
spinlock_api_smp.h: fix preprocessor comments
treewide: Fix typo in printk
doc: device tree: clarify stuff in usage-model.txt.
open firmware: "/aliasas" -> "/aliases"
md: bcache: Fixed a typo with the word 'arithmetic'
irq/generic-chip: fix a few kernel-doc entries
frv: Convert use of typedef ctl_table to struct ctl_table
sgi: xpc: Convert use of typedef ctl_table to struct ctl_table
doc: clk: Fix incorrect wording
Documentation/arm/IXP4xx fix a typo
Documentation/networking/ieee802154 fix a typo
Documentation/DocBook/media/v4l fix a typo
Documentation/video4linux/si476x.txt fix a typo
Documentation/virtual/kvm/api.txt fix a typo
Documentation/early-userspace/README fix a typo
Documentation/video4linux/soc-camera.txt fix a typo
lguest: fix CONFIG_PAE -> CONFIG_x86_PAE in comment
...
MD: Remember the last sync operation that was performed
This patch adds a field to the mddev structure to track the last
sync operation that was performed. This is especially useful when
it comes to what is recorded in mismatch_cnt in sysfs. If the
last operation was "data-check", then it reports the number of
descrepancies found by the user-initiated check. If it was a
"repair" operation, then it is reporting the number of
descrepancies repaired. etc.
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
DM RAID: Add ability to restore transiently failed devices on resume
This patch adds code to the resume function to check over the devices
in the RAID array. If any are found to be marked as failed and their
superblocks can be read, an attempt is made to reintegrate them into
the array. This allows the user to refresh the array with a simple
suspend and resume of the array - rather than having to load a
completely new table, allocate and initialize all the structures and
throw away the old instantiation.
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
