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path: root/drivers/md/bcache/btree.c
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2014-08-04bcache: try to set b->parent properlySlava Pestov
bcache_flash_dev.ktest would reliably crash with 8k and 16k bucket size before; now it passes. Change-Id: Ib542232235e39298c3a7548fe52b645cabb823d1
2014-08-04bcache: fix use-after-free in btree_gc_coalesce()Slava Pestov
If we goto out_nocoalesce after we free new_nodes[0], we end up freeing new_nodes[0] again. This was generating a lockdep warning. The fix is to set new_nodes[0] to NULL, since the out_nocoalesce path safely ignores NULL entries in the new_nodes array. This regression was introduced in 2d7f9531. Change-Id: I76564d7257800583214376b4bacf236cda90c89c
2014-08-04bcache: fix crash in bcache_btree_node_alloc_fail tracepointSlava Pestov
'b' was NULL. Change-Id: Icac0fd04afa2d23f213d96d51afd53374e6dd0c0
2014-08-04bcache: Allocate bounce buffers with GFP_NOWAITKent Overstreet
There's no point in blocking on these allocations, since our fallback paths will probably go faster than blocking. Change-Id: I733ca202c25cb36bde02607a0a60552229a4241c
2014-08-04bcache: Make sure to pass GFP_WAIT to mempool_alloc()Kent Overstreet
this was very wrong - mempool_alloc() only guarantees success with GFP_WAIT. bcache uses GFP_NOWAIT in various other places where we have a fallback, circuits must've gotten crossed when writing this code or something. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-08-04bcache: wait for buckets when allocating new btree rootSlava Pestov
Tested: - sometimes bcache_tier test would hang on startup with a failure to allocate the btree root -- no longer seeing this Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-03-18bcache: Kill bucket->gc_genKent Overstreet
gc_gen was a temporary used to recalculate last_gc, but since we only need bucket->last_gc when gc isn't running (gc_mark_valid = 1), we can just update last_gc directly. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-03-18bcache: Kill unused freelistKent Overstreet
This was originally added as at optimization that for various reasons isn't needed anymore, but it does add a lot of nasty corner cases (and it was responsible for some recently fixed bugs). Just get rid of it now. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-03-18bcache: Rework btree cache reserve handlingKent Overstreet
This changes the bucket allocation reserves to use _real_ reserves - separate freelists - instead of watermarks, which if nothing else makes the current code saner to reason about and is going to be important in the future when we add support for multiple btrees. It also adds btree_check_reserve(), which checks (and locks) the reserves for both bucket allocation and memory allocation for btree nodes; the old code just kinda sorta assumed that since (e.g. for btree node splits) it had the root locked and that meant no other threads could try to make use of the same reserve; this technically should have been ok for memory allocation (we should always have a reserve for memory allocation (the btree node cache is used as a reserve and we preallocate it)), but multiple btrees will mean that locking the root won't be sufficient anymore, and for the bucket allocation reserve it was technically possible for the old code to deadlock. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-03-18bcache: Kill btree_io_wqKent Overstreet
With the locking rework in the last patch, this shouldn't be needed anymore - btree_node_write_work() only takes b->write_lock which is never held for very long. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-03-18bcache: btree locking reworkKent Overstreet
Add a new lock, b->write_lock, which is required to actually modify - or write - a btree node; this lock is only held for short durations. This means we can write out a btree node without taking b->lock, which _is_ held for long durations - solving a deadlock when btree_flush_write() (from the journalling code) is called with a btree node locked. Right now just occurs in bch_btree_set_root(), but with an upcoming journalling rework is going to happen a lot more. This also turns b->lock is now more of a read/intent lock instead of a read/write lock - but not completely, since it still blocks readers. May turn it into a real intent lock at some point in the future. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-03-18bcache: Fix a race when freeing btree nodesKent Overstreet
This isn't a bulletproof fix; btree_node_free() -> bch_bucket_free() puts the bucket on the unused freelist, where it can be reused right away without any ordering requirements. It would be better to wait on at least a journal write to go down before reusing the bucket. bch_btree_set_root() does this, and inserting into non leaf nodes is completely synchronous so we should be ok, but future patches are just going to get rid of the unused freelist - it was needed in the past for various reasons but shouldn't be anymore. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-03-18bcache: Add a real GC_MARK_RECLAIMABLEKent Overstreet
This means the garbage collection code can better check for data and metadata pointers to the same buckets. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-03-18bcache: Kill dead cgroup codeKent Overstreet
This hasn't been used or even enabled in ages. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-03-18bcache: Fix another bug recovering from unclean shutdownKent Overstreet
The on disk bucket gens are allowed to be out of date, when we reuse buckets that didn't have any live data in them. To deal with this, the initial gc has to update the bucket gen when we find a pointer gen newer than the bucket's gen. Unfortunately we weren't doing this for pointers in the journal that we're about to replay. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-03-18bcache: Fix a bug recovering from unclean shutdownKent Overstreet
The code to fixup incorrect bucket prios incorrectly did not skip btree node freeing keys Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-29bcache: Minor fixes from kbuild robotKent Overstreet
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-29bcache: fix BUG_ON due to integer overflow with GC_SECTORS_USEDDarrick J. Wong
The BUG_ON at the end of __bch_btree_mark_key can be triggered due to an integer overflow error: BITMASK(GC_SECTORS_USED, struct bucket, gc_mark, 2, 13); ... SET_GC_SECTORS_USED(g, min_t(unsigned, GC_SECTORS_USED(g) + KEY_SIZE(k), (1 << 14) - 1)); BUG_ON(!GC_SECTORS_USED(g)); In bcache.h, the SECTORS_USED bitfield is defined to be 13 bits wide. While the SET_ code tries to ensure that the field doesn't overflow by clamping it to (1<<14)-1 == 16383, this is incorrect because 16383 requires 14 bits. Therefore, if GC_SECTORS_USED() + KEY_SIZE() = 8192, the SET_ statement tries to store 8192 into a 13-bit field. In a 13-bit field, 8192 becomes zero, thus triggering the BUG_ON. Therefore, create a field width constant and a max value constant, and use those to create the bitfield and check the inputs to SET_GC_SECTORS_USED. Arguably the BITMASK() template ought to have BUG_ON checks for too-large values, but that's a separate patch. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2014-01-08bcache: Don't return -EINTR when insert finishedKent Overstreet
We need to return -EINTR after a split because we invalidated iterators (and freed the btree node) - but if we were finished inserting, we don't want to redo the traversal. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-08bcache: Move insert_fixup() to btree_keys_opsKent Overstreet
Now handling overlapping extents/keys is a method that's specific to what the btree node contains. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-08bcache: Convert sorting to btree_keysKent Overstreet
More work to disentangle various code from struct btree Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-08bcache: Convert debug code to btree_keysKent Overstreet
More work to disentangle various code from struct btree Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-08bcache: Convert btree_iter to struct btree_keysKent Overstreet
More work to disentangle bset.c from struct btree Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-08bcache: Add bch_btree_keys_u64s_remaining()Kent Overstreet
Helper function to explicitly check how much space is free in a btree node Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-08bcache: Add struct btree_keysKent Overstreet
Soon, bset.c won't need to depend on struct btree. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-08bcache: Abstract out stuff needed for sortingKent Overstreet
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-08bcache: Rename/shuffle various code aroundKent Overstreet
More work to disentangle bset.c from the rest of the code: Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-08bcache: Add struct bset_sort_stateKent Overstreet
More disentangling bset.c from the rest of the bcache code - soon, the sorting routines won't have any dependencies on any outside structs. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-08bcache: Split out sort_extent_cmp()Kent Overstreet
Only use extent comparison for comparing extents, so we're not using START_KEY() on other key types (i.e. btree pointers) Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-08bcache: Bkey indexing renamingKent Overstreet
More refactoring: node() -> bset_bkey_idx() end() -> bset_bkey_last() Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-08bcache: Make bch_keylist_realloc() take u64s, not nptrsKent Overstreet
Getting away from KEY_PTRS and moving toward KEY_U64s - and getting rid of magic 2s Also - split out the part that checks against journal entry size so as to avoid a dependancy on struct cache_set in bset.c Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-08bcache: Btree verify code improvementsKent Overstreet
Used this fixed code to find and fix the bug fixed by a4d885097b0ac0cd1337f171f2d4b83e946094d4. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-08bcache: kill index()Kent Overstreet
That was a terrible name for a macro, add some better helpers to replace it. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-08bcache: Do bkey_put() in btree_split() error pathKent Overstreet
This error path shouldn't have been hit in practice.. and we've got reworked reserve code coming soon so that it shouldn't _ever_ be bit... but if we've got code for this error path it should be correct. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-08bcache: Rework allocator reservesKent Overstreet
We need a reserve for allocating buckets for new btree nodes - and now that we've got multiple btrees, it really needs to be per btree. This reworks the reserves so we've got separate freelists for each reserve instead of watermarks, which seems to make things a bit cleaner, and it adds some code so that btree_split() can make sure the reserve is available before it starts. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-08bcache: kill closure locking usageKent Overstreet
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-01-08bcache: Minor btree cache fixKent Overstreet
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-12-31Merge tag 'v3.13-rc6' into for-3.14/coreJens Axboe
Needed to bring blk-mq uptodate, since changes have been going in since for-3.14/core was established. Fixup merge issues related to the immutable biovec changes. Signed-off-by: Jens Axboe <axboe@kernel.dk> Conflicts: block/blk-flush.c fs/btrfs/check-integrity.c fs/btrfs/extent_io.c fs/btrfs/scrub.c fs/logfs/dev_bdev.c
2013-12-16bcache: fix for gc and writeback raceNicholas Swenson
Garbage collector needs to check keys in the writeback keybuf to make sure it's not invalidating buckets to which the writeback keys point to. Signed-off-by: Nicholas Swenson <nks@daterainc.com> Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-12-16bcache: Fix dirty_data accountingKent Overstreet
Dirty data accounting wasn't quite right - firstly, we were adding the key we're inserting after it could have merged with another dirty key already in the btree, and secondly we could sometimes pass the wrong offset to bcache_dev_sectors_dirty_add() for dirty data we were overwriting - which is important when tracking dirty data by stripe. NOTE FOR BACKPORTERS: For 3.10 (and 3.11?) there's other accounting fixes necessary that got squashed in with other patches; the full patch against 3.10 is 408cc2f47eeac93a, available at: git://evilpiepirate.org/~kent/linux-bcache.git bcache-3.10-writeback-fixes Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: linux-stable <stable@vger.kernel.org> # >= v3.10 diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c index 2a46036..4a12b2f 100644 --- a/drivers/md/bcache/btree.c +++ b/drivers/md/bcache/btree.c @@ -1817,7 +1817,8 @@ static bool fix_overlapping_extents(struct btree *b, struct bkey *insert, if (KEY_START(k) > KEY_START(insert) + sectors_found) goto check_failed; - if (KEY_PTRS(replace_key) != KEY_PTRS(k)) + if (KEY_PTRS(k) != KEY_PTRS(replace_key) || + KEY_DIRTY(k) != KEY_DIRTY(replace_key)) goto check_failed; /* skip past gen */
2013-11-29bcache: fix sparse non static symbol warningWei Yongjun
Fixes the following sparse warning: drivers/md/bcache/btree.c:2220:5: warning: symbol 'btree_insert_fn' was not declared. Should it be static? Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-24block: Convert bio_for_each_segment() to bvec_iterKent Overstreet
More prep work for immutable biovecs - with immutable bvecs drivers won't be able to use the biovec directly, they'll need to use helpers that take into account bio->bi_iter.bi_bvec_done. This updates callers for the new usage without changing the implementation yet. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: "Ed L. Cashin" <ecashin@coraid.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Lars Ellenberg <drbd-dev@lists.linbit.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Paul Clements <Paul.Clements@steeleye.com> Cc: Jim Paris <jim@jtan.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Yehuda Sadeh <yehuda@inktank.com> Cc: Sage Weil <sage@inktank.com> Cc: Alex Elder <elder@inktank.com> Cc: ceph-devel@vger.kernel.org Cc: Joshua Morris <josh.h.morris@us.ibm.com> Cc: Philip Kelleher <pjk1939@linux.vnet.ibm.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Neil Brown <neilb@suse.de> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux390@de.ibm.com Cc: Nagalakshmi Nandigama <Nagalakshmi.Nandigama@lsi.com> Cc: Sreekanth Reddy <Sreekanth.Reddy@lsi.com> Cc: support@lsi.com Cc: "James E.J. Bottomley" <JBottomley@parallels.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> Cc: Tejun Heo <tj@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Guo Chao <yan@linux.vnet.ibm.com> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Keith Busch <keith.busch@intel.com> Cc: Stephen Hemminger <shemminger@vyatta.com> Cc: Quoc-Son Anh <quoc-sonx.anh@intel.com> Cc: Sebastian Ott <sebott@linux.vnet.ibm.com> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Seth Jennings <sjenning@linux.vnet.ibm.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: "Darrick J. Wong" <darrick.wong@oracle.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Jan Kara <jack@suse.cz> Cc: linux-m68k@lists.linux-m68k.org Cc: linuxppc-dev@lists.ozlabs.org Cc: drbd-user@lists.linbit.com Cc: nbd-general@lists.sourceforge.net Cc: cbe-oss-dev@lists.ozlabs.org Cc: xen-devel@lists.xensource.com Cc: virtualization@lists.linux-foundation.org Cc: linux-raid@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: DL-MPTFusionLinux@lsi.com Cc: linux-scsi@vger.kernel.org Cc: devel@driverdev.osuosl.org Cc: linux-fsdevel@vger.kernel.org Cc: cluster-devel@redhat.com Cc: linux-mm@kvack.org Acked-by: Geoff Levand <geoff@infradead.org>
2013-11-24block: Abstract out bvec iteratorKent Overstreet
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 <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: "Ed L. Cashin" <ecashin@coraid.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Lars Ellenberg <drbd-dev@lists.linbit.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Yehuda Sadeh <yehuda@inktank.com> Cc: Sage Weil <sage@inktank.com> Cc: Alex Elder <elder@inktank.com> Cc: ceph-devel@vger.kernel.org Cc: Joshua Morris <josh.h.morris@us.ibm.com> Cc: Philip Kelleher <pjk1939@linux.vnet.ibm.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Neil Brown <neilb@suse.de> Cc: Alasdair Kergon <agk@redhat.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: dm-devel@redhat.com Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux390@de.ibm.com Cc: Boaz Harrosh <bharrosh@panasas.com> Cc: Benny Halevy <bhalevy@tonian.com> Cc: "James E.J. Bottomley" <JBottomley@parallels.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Chris Mason <chris.mason@fusionio.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Jaegeuk Kim <jaegeuk.kim@samsung.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Dave Kleikamp <shaggy@kernel.org> Cc: Joern Engel <joern@logfs.org> Cc: Prasad Joshi <prasadjoshi.linux@gmail.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Ben Myers <bpm@sgi.com> Cc: xfs@oss.sgi.com Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Guo Chao <yan@linux.vnet.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Cc: "Roger Pau Monné" <roger.pau@citrix.com> Cc: Jan Beulich <jbeulich@suse.com> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Cc: Ian Campbell <Ian.Campbell@citrix.com> Cc: Sebastian Ott <sebott@linux.vnet.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Jerome Marchand <jmarchand@redhat.com> Cc: Joe Perches <joe@perches.com> Cc: Peng Tao <tao.peng@emc.com> Cc: Andy Adamson <andros@netapp.com> Cc: fanchaoting <fanchaoting@cn.fujitsu.com> Cc: Jie Liu <jeff.liu@oracle.com> Cc: Sunil Mushran <sunil.mushran@gmail.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Namjae Jeon <namjae.jeon@samsung.com> Cc: Pankaj Kumar <pankaj.km@samsung.com> Cc: Dan Magenheimer <dan.magenheimer@oracle.com> Cc: Mel Gorman <mgorman@suse.de>6
2013-11-11bcache: Better full stripe scanningKent Overstreet
The old scanning-by-stripe code burned too much CPU, this should be better. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-11bcache: Have btree_split() insert into parent directlyKent Overstreet
The flow control in btree_insert_node() was... fragile... before, this'll use more stack (but since our btrees are never more than depth 1, that shouldn't matter) and it should be significantly clearer and less fragile. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-11bcache: Move spinlock into struct time_statsKent Overstreet
Minor cleanup. Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-11bcache: Kill bch_next_recurse_key()Kent Overstreet
This dates from before the btree iterator, and now it's finally gone Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-11bcache: Avoid deadlocking in garbage collectionKent Overstreet
Not a complete fix - we could still deadlock if btree_insert_node() has to split... Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-11bcache: Incremental gcKent Overstreet
Big garbage collection rewrite; now, garbage collection uses the same mechanisms as used elsewhere for inserting/updating btree node pointers, instead of rewriting interior btree nodes in place. This makes the code significantly cleaner and less fragile, and means we can now make garbage collection incremental - it doesn't have to hold a write lock on the root of the btree for the entire duration of garbage collection. This means that there's less of a latency hit for doing garbage collection, which means we can gc more frequently (and do a better job of reclaiming from the cache), and we can coalesce across more btree nodes (improving our space efficiency). Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-11bcache: Add make_btree_freeing_key()Kent Overstreet
Refactoring, prep work for incremental garbage collection. Signed-off-by: Kent Overstreet <kmo@daterainc.com>