kernel.git/drivers/md/persistent-data/dm-space-map-common.c, branch linux-4.9.y

dm space map common: add bounds check to sm_ll_lookup_bitmap()

2022-01-27T07:47:38Z

[ Upstream commit cba23ac158db7f3cd48a923d6861bee2eb7a2978 ] Corrupted metadata could warrant returning error from sm_ll_lookup_bitmap(). Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Sasha Levin

dm space map common: fix division bug in sm_ll_find_free_block()

2021-05-22T08:40:20Z

commit 5208692e80a1f3c8ce2063a22b675dd5589d1d80 upstream. 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 Tested-by: Ming-Hung Tsai Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm space map common: fix to ensure new block isn't already in use

2020-02-14T21:31:01Z

commit 4feaef830de7ffdd8352e1fe14ad3bf13c9688f8 upstream. 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 Cc: stable@vger.kernel.org Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm persistent data: eliminate unnecessary return values

2015-10-31T23:06:02Z

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 Signed-off-by: Mike Snitzer

dm space map common: make sure new space is used during extend

2014-01-08T02:05:17Z

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 Signed-off-by: Mike Snitzer Cc: stable@vger.kernel.org

dm space map: disallow decrementing a reference count below zero

2013-12-13T19:22:09Z

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 Signed-off-by: Mike Snitzer Cc: stable@vger.kernel.org # 3.12+

dm space map: optimise sm_ll_dec and sm_ll_inc

2013-08-23T13:02:14Z

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

dm persistent data: use DMERR_LIMIT for errors

2012-12-21T20:23:34Z

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 Signed-off-by: Alasdair G Kergon

dm persistent data: convert to use le32_add_cpu

2012-10-12T15:59:47Z

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 Signed-off-by: Alasdair G Kergon

dm persistent data: only commit space map if index changed

2012-07-27T14:08:06Z

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