linux/drivers/md/persistent-data, branch v3.9

dm thin: fix discard corruption

2013-03-20T17:21:24Z

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 Signed-off-by: Alasdair G Kergon

dm: add cache target

2013-03-01T22:45:51Z

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 Signed-off-by: Heinz Mauelshagen Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon

dm persistent data: add bitset

2013-03-01T22:45:51Z

Add a persistent bitset as a wrapper around dm-array. Signed-off-by: Joe Thornber Signed-off-by: Alasdair G Kergon

dm persistent data: add transactional array

2013-03-01T22:45:51Z

Add a transactional array. Signed-off-by: Joe Thornber Signed-off-by: Alasdair G Kergon

dm persistent data: add btree_walk

2013-03-01T22:45:50Z

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 Signed-off-by: Alasdair G Kergon

dm persistent data: set some btree fn parms const

2013-03-01T22:45:47Z

Mark some constant parameters constant in some dm-btree functions. Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon

dm persistent data: remove CONFIG_EXPERIMENTAL

2013-03-01T22:45:46Z

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 Signed-off-by: Alasdair G Kergon

hlist: drop the node parameter from iterators

2013-02-28T03:10:24Z

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 Acked-by: Paul E. McKenney Signed-off-by: Sasha Levin Cc: Wu Fengguang Cc: Marcelo Tosatti Cc: Gleb Natapov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

drivers/md/persistent-data/dm-transaction-manager.c: rename HASH_SIZE

2013-02-24T01:50:08Z

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 Cc: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge tag 'dm-3.8-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm

2012-12-22T01:08:06Z

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 ...