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path: root/drivers/md/persistent-data/dm-space-map-common.c
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2023-02-14dm: avoid useless 'else' after 'break' or return'Heinz Mauelshagen1-6/+5
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-02-14dm: prefer '"%s...", __func__'Heinz Mauelshagen1-2/+2
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-02-14dm: add missing empty linesHeinz Mauelshagen1-0/+6
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-02-14dm: address indent/space issuesHeinz Mauelshagen1-1/+1
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-02-14dm: change "unsigned" to "unsigned int"Heinz Mauelshagen1-14/+14
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-02-14dm: add missing SPDX-License-IndentifiersHeinz Mauelshagen1-0/+1
'GPL-2.0-only' is used instead of 'GPL-2.0' because SPDX has deprecated its use. Suggested-by: John Wiele <jwiele@redhat.com> Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2022-01-04dm space map common: add bounds check to sm_ll_lookup_bitmap()Joe Thornber1-0/+5
Corrupted metadata could warrant returning error from sm_ll_lookup_bitmap(). Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2021-06-04dm space map disk: cache a small number of index entriesJoe Thornber1-6/+80
The disk space map stores it's index entries in a btree, these are accessed very frequently, so having a few cached makes a big difference to performance. With this change provisioning a new block takes roughly 20% less cpu. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2021-06-04dm space maps: improve performance with inc/dec on ranges of blocksJoe Thornber1-26/+422
When we break sharing on btree nodes we typically need to increment the reference counts to every value held in the node. This can cause a lot of repeated calls to the space maps. Fix this by changing the interface to the space map inc/dec methods to take ranges of adjacent blocks to be operated on. For installations that are using a lot of snapshots this will reduce cpu overhead of fundamental operations such as provisioning a new block, or deleting a snapshot, by as much as 10 times. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2021-04-19dm space map common: fix division bug in sm_ll_find_free_block()Joe Thornber1-0/+2
This division bug meant the search for free metadata space could skip the final allocation bitmap's worth of entries. Fix affects DM thinp, cache and era targets. Cc: stable@vger.kernel.org Signed-off-by: Joe Thornber <ejt@redhat.com> Tested-by: Ming-Hung Tsai <mtsai@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-15dm space map common: fix to ensure new block isn't already in useJoe Thornber1-0/+27
The space-maps track the reference counts for disk blocks allocated by both the thin-provisioning and cache targets. There are variants for tracking metadata blocks and data blocks. Transactionality is implemented by never touching blocks from the previous transaction, so we can rollback in the event of a crash. When allocating a new block we need to ensure the block is free (has reference count of 0) in both the current and previous transaction. Prior to this fix we were doing this by searching for a free block in the previous transaction, and relying on a 'begin' counter to track where the last allocation in the current transaction was. This 'begin' field was not being updated in all code paths (eg, increment of a data block reference count due to breaking sharing of a neighbour block in the same btree leaf). This fix keeps the 'begin' field, but now it's just a hint to speed up the search. Instead the current transaction is searched for a free block, and then the old transaction is double checked to ensure it's free. Much simpler. This fixes reports of sm_disk_new_block()'s BUG_ON() triggering when DM thin-provisioning's snapshots are heavily used. Reported-by: Eric Wheeler <dm-devel@lists.ewheeler.net> Cc: stable@vger.kernel.org Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-26dm space map common: remove check for impossible sm_find_free() return valueZhangXiaoxu1-4/+0
The function sm_find_free() just returns -ENOSPC and 0. So remove lone caller's check for some other error. Signed-off-by: ZhangXiaoxu <zhangxiaoxu5@huawei.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-04-18dm space map common: zero entire ll_diskMike Snitzer1-0/+2
Otherwise, memory that is allocated (and potentially not previously zeroed) will get written to disk as part of the space maps. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-08-02dm: Avoid namespace collision with bitmap APIAndy Shevchenko1-10/+10
bitmap API (include/linux/bitmap.h) has 'bitmap' prefix for its methods. On the other hand DM bitmap API is special case. Adding 'dm' prefix to it to avoid potential name space collision. No functional changes intended. Suggested-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2017-02-16dm space map common: memcpy the disk root to ensure it's arch alignedJoe Thornber1-5/+11
The metadata_space_map_root passed to sm_ll_open_metadata() may or may not be arch aligned, use memcpy to ensure it is. This is not a fast path so the extra memcpy doesn't hurt us. Long-term it'd be better to use the kernel's alignment infrastructure to remove the memcpy()s that are littered across persistent-data (btree, array, space-maps, etc). Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-12-08dm space map: always set ev if sm_ll_mutate() succeedsBenjamin Marzinski1-1/+2
If no block was allocated or freed, sm_ll_mutate() wasn't setting *ev, leaving the variable unitialized. sm_ll_insert(), sm_disk_inc_block(), and sm_disk_new_block() all check ev to see if there was an allocation event in sm_ll_mutate(), possibly reading unitialized data. If no allocation event occured, sm_ll_mutate() should set *ev to SM_NONE. Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-12-08dm space map metadata: skip useless memcpy in metadata_ll_init_index()Benjamin Marzinski1-1/+0
When metadata_ll_init_index() is called by sm_ll_new_metadata(), ll->mi_le hasn't been initialized yet. So, when metadata_ll_init_index() copies the contents of ll->mi_le into the newly allocated bitmap_root, it is just copying garbage. ll->mi_le will be allocated later in sm_ll_extend() and copied into the bitmap_root, in sm_ll_commit(). Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-11-01dm persistent data: eliminate unnecessary return valuesMikulas Patocka1-16/+16
dm_bm_unlock and dm_tm_unlock return an integer value but the returned value is always 0. The calling code sometimes checks the return value and sometimes doesn't. Eliminate these unnecessary return values and also the checks for them. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-08dm space map common: make sure new space is used during extendJoe Thornber1-1/+5
When extending a low level space map we should update nr_blocks at the start so the new space is used for the index entries. Otherwise extend can fail, e.g.: sm_metadata_extend call sequence that fails: -> sm_ll_extend -> dm_tm_new_block -> dm_sm_new_block -> sm_bootstrap_new_block => returns -ENOSPC because smm->begin == smm->ll.nr_blocks Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
2013-12-13dm space map: disallow decrementing a reference count below zeroJoe Thornber1-9/+23
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+
2013-08-23dm space map: optimise sm_ll_dec and sm_ll_incJoe Thornber1-28/+49
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>
2012-12-22dm persistent data: use DMERR_LIMIT for errorsMike Snitzer1-8/+8
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>
2012-10-12dm persistent data: convert to use le32_add_cpuWei Yongjun1-2/+2
Convert cpu_to_le32(le32_to_cpu(E1) + E2) to use le32_add_cpu(). dpatch engine is used to auto generate this patch. (https://github.com/weiyj/dpatch) Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27dm persistent data: only commit space map if index changedJoe Thornber1-1/+11
Introduce bitmap_index_changed to track whether or not the index changed then only commit a space map if it did. 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>
2012-03-28dm persistent data: remove space map ref_count entries if redundantJoe Thornber1-3/+0
Save space by removing entries from the space map ref_count tree if they're no longer needed. Ref counts are stored in two places: a bitmap if the ref_count is below 3, or a btree of uint32_t if 3 or above. When a ref_count that was above 3 drops below we can remove it from the tree and save some metadata space. This removal was commented out before because I was unsure why this was causing under-populated btree nodes. Earlier patches have fixed this issue. 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>
2011-11-01dm: add persistent data libraryJoe Thornber1-0/+705
The persistent-data library offers a re-usable framework for the storage and management of on-disk metadata in device-mapper targets. It's used by the thin-provisioning target in the next patch and in an upcoming hierarchical storage target. For further information, please read Documentation/device-mapper/persistent-data.txt Signed-off-by: Joe Thornber <thornber@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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