4feaef830d
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> |
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| .. | ||
| dm-array.c | ||
| dm-array.h | ||
| dm-bitset.c | ||
| dm-bitset.h | ||
| dm-block-manager.c | ||
| dm-block-manager.h | ||
| dm-btree-internal.h | ||
| dm-btree-remove.c | ||
| dm-btree-spine.c | ||
| dm-btree.c | ||
| dm-btree.h | ||
| dm-persistent-data-internal.h | ||
| dm-space-map-common.c | ||
| dm-space-map-common.h | ||
| dm-space-map-disk.c | ||
| dm-space-map-disk.h | ||
| dm-space-map-metadata.c | ||
| dm-space-map-metadata.h | ||
| dm-space-map.h | ||
| dm-transaction-manager.c | ||
| dm-transaction-manager.h | ||
| Kconfig | ||
| Makefile | ||