An old array block could have its reference count decremented below
zero when it is being replaced in the btree by a new array block.
The fix is to increment the old ablock's reference count just before
inserting a new ablock into the btree.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.9+
The old behaviour, returning -EINVAL if a ref_count of 0 would be
decremented, was removed in commit f722063 ("dm space map: optimise
sm_ll_dec and sm_ll_inc"). To fix this regression we return an error
code from the mutator function pointer passed to sm_ll_mutate() and have
dec_ref_count() return -EINVAL if the old ref_count is 0.
Add a DMERR to reflect the potential seriousness of this error.
Also, add missing dm_tm_unlock() to sm_ll_mutate()'s error path.
With this fix the following dmts regression test now passes:
dmtest run --suite cache -n /metadata_use_kernel/
The next patch fixes the higher-level dm-array code that exposed this
regression.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.12+
A thin-pool may be in read-only mode because the pool's data or metadata
space was exhausted. To allow for recovery, by adding more space to the
pool, we must allow a pool to transition from PM_READ_ONLY to PM_WRITE
mode. Otherwise, running out of space will render the pool permanently
read-only.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
Don't waste time spotting blocks that have been allocated and then freed
in the same transaction.
The extra lookup is expensive, and I don't think it really gives us much.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Prior to this patch these methods did a lookup followed by an insert.
Instead they now call a common mutate function that adjusts the value
according to a callback function. This avoids traversing the data
structures twice and hence improves performance.
Also factor out sm_ll_lookup_big_ref_count() for use by both
sm_ll_lookup() and sm_ll_mutate().
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
dm-btree now takes advantage of dm-bufio's ability to prefetch data via
dm_bm_prefetch(). Prior to this change many btree node visits were
causing a synchronous read.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Remove a visited leaf straight away from the stack, rather than
marking all it's children as visited and letting it get removed on the
next iteration. May also offer a micro optimisation in dm_btree_del.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Add a threshold callback to dm persistent data space maps.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Add a threshold callback function to the persistent data space map
interface for a subsequent patch to use.
dm-thin and dm-cache are interested in knowing when they're getting
low on metadata or data blocks. This patch introduces a new method
for registering a callback against a threshold.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Support extending a dm persistent data metadata space map.
The extend itself is implemented by switching back to the boostrap
allocator and pointing to the new space. The extra bitmap indexes are
then allocated from the new space, and finally we switch back to the
proper space map ops and tweak the reference counts.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Fix some typos in dm-space-map-metadata.c error messages.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Fix a bug in dm_btree_remove that could leave leaf values with incorrect
reference counts. The effect of this was that removal of a shared block
could result in the space maps thinking the block was no longer used.
More concretely, if you have a thin device and a snapshot of it, sending
a discard to a shared region of the thin could corrupt the snapshot.
Thinp uses a 2-level nested btree to store it's mappings. This first
level is indexed by thin device, and the second level by logical
block.
Often when we're removing an entry in this mapping tree we need to
rebalance nodes, which can involve shadowing them, possibly creating a
copy if the block is shared. If we do create a copy then children of
that node need to have their reference counts incremented. In this
way reference counts percolate down the tree as shared trees diverge.
The rebalance functions were incrementing the children at the
appropriate time, but they were always assuming the children were
internal nodes. This meant the leaf values (in our case packed
block/flags entries) were not being incremented.
Cc: stable@vger.kernel.org
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Add a target that allows a fast device such as an SSD to be used as a
cache for a slower device such as a disk.
A plug-in architecture was chosen so that the decisions about which data
to migrate and when are delegated to interchangeable tunable policy
modules. The first general purpose module we have developed, called
"mq" (multiqueue), follows in the next patch. Other modules are
under development.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Heinz Mauelshagen <mauelshagen@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Add dm_btree_walk to iterate through the contents of a btree.
This will be used by the dm cache target.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Mark some constant parameters constant in some dm-btree functions.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
The CONFIG_EXPERIMENTAL config item has not carried much meaning for a
while now and is almost always enabled by default. As agreed during the
Linux kernel summit, remove it from any "depends on" lines in Kconfigs.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
I'm not sure why, but the hlist for each entry iterators were conceived
list_for_each_entry(pos, head, member)
The hlist ones were greedy and wanted an extra parameter:
hlist_for_each_entry(tpos, pos, head, member)
Why did they need an extra pos parameter? I'm not quite sure. Not only
they don't really need it, it also prevents the iterator from looking
exactly like the list iterator, which is unfortunate.
Besides the semantic patch, there was some manual work required:
- Fix up the actual hlist iterators in linux/list.h
- Fix up the declaration of other iterators based on the hlist ones.
- A very small amount of places were using the 'node' parameter, this
was modified to use 'obj->member' instead.
- Coccinelle didn't handle the hlist_for_each_entry_safe iterator
properly, so those had to be fixed up manually.
The semantic patch which is mostly the work of Peter Senna Tschudin is here:
@@
iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;
type T;
expression a,c,d,e;
identifier b;
statement S;
@@
-T b;
<+... when != b
(
hlist_for_each_entry(a,
- b,
c, d) S
|
hlist_for_each_entry_continue(a,
- b,
c) S
|
hlist_for_each_entry_from(a,
- b,
c) S
|
hlist_for_each_entry_rcu(a,
- b,
c, d) S
|
hlist_for_each_entry_rcu_bh(a,
- b,
c, d) S
|
hlist_for_each_entry_continue_rcu_bh(a,
- b,
c) S
|
for_each_busy_worker(a, c,
- b,
d) S
|
ax25_uid_for_each(a,
- b,
c) S
|
ax25_for_each(a,
- b,
c) S
|
inet_bind_bucket_for_each(a,
- b,
c) S
|
sctp_for_each_hentry(a,
- b,
c) S
|
sk_for_each(a,
- b,
c) S
|
sk_for_each_rcu(a,
- b,
c) S
|
sk_for_each_from
-(a, b)
+(a)
S
+ sk_for_each_from(a) S
|
sk_for_each_safe(a,
- b,
c, d) S
|
sk_for_each_bound(a,
- b,
c) S
|
hlist_for_each_entry_safe(a,
- b,
c, d, e) S
|
hlist_for_each_entry_continue_rcu(a,
- b,
c) S
|
nr_neigh_for_each(a,
- b,
c) S
|
nr_neigh_for_each_safe(a,
- b,
c, d) S
|
nr_node_for_each(a,
- b,
c) S
|
nr_node_for_each_safe(a,
- b,
c, d) S
|
- for_each_gfn_sp(a, c, d, b) S
+ for_each_gfn_sp(a, c, d) S
|
- for_each_gfn_indirect_valid_sp(a, c, d, b) S
+ for_each_gfn_indirect_valid_sp(a, c, d) S
|
for_each_host(a,
- b,
c) S
|
for_each_host_safe(a,
- b,
c, d) S
|
for_each_mesh_entry(a,
- b,
c, d) S
)
...+>
[akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
[akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
[akpm@linux-foundation.org: checkpatch fixes]
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foudnation.org: redo intrusive kvm changes]
Tested-by: Peter Senna Tschudin <peter.senna@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix the warning:
drivers/md/persistent-data/dm-transaction-manager.c:28:1: warning: "HASH_SIZE" redefined
In file included from include/linux/elevator.h:5,
from include/linux/blkdev.h:216,
from drivers/md/persistent-data/dm-block-manager.h:11,
from drivers/md/persistent-data/dm-transaction-manager.h:10,
from drivers/md/persistent-data/dm-transaction-manager.c:6:
include/linux/hashtable.h:22:1: warning: this is the location of the previous definition
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull dm update from Alasdair G Kergon:
"Miscellaneous device-mapper fixes, cleanups and performance
improvements.
Of particular note:
- Disable broken WRITE SAME support in all targets except linear and
striped. Use it when kcopyd is zeroing blocks.
- Remove several mempools from targets by moving the data into the
bio's new front_pad area(which dm calls 'per_bio_data').
- Fix a race in thin provisioning if discards are misused.
- Prevent userspace from interfering with the ioctl parameters and
use kmalloc for the data buffer if it's small instead of vmalloc.
- Throttle some annoying error messages when I/O fails."
* tag 'dm-3.8-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm: (36 commits)
dm stripe: add WRITE SAME support
dm: remove map_info
dm snapshot: do not use map_context
dm thin: dont use map_context
dm raid1: dont use map_context
dm flakey: dont use map_context
dm raid1: rename read_record to bio_record
dm: move target request nr to dm_target_io
dm snapshot: use per_bio_data
dm verity: use per_bio_data
dm raid1: use per_bio_data
dm: introduce per_bio_data
dm kcopyd: add WRITE SAME support to dm_kcopyd_zero
dm linear: add WRITE SAME support
dm: add WRITE SAME support
dm: prepare to support WRITE SAME
dm ioctl: use kmalloc if possible
dm ioctl: remove PF_MEMALLOC
dm persistent data: improve improve space map block alloc failure message
dm thin: use DMERR_LIMIT for errors
...
Improve space map error message when unable to allocate a new
metadata block.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Nearly all of persistent-data is in the IO path so throttle error
messages with DMERR_LIMIT to limit the amount logged when
something has gone wrong.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
