forked from Minki/linux
474e559567
We got the following warnings from thin_check during thin-pool setup: $ thin_check /dev/vdb examining superblock examining devices tree missing devices: [1, 84] too few entries in btree_node: 41, expected at least 42 (block 138, max_entries = 126) examining mapping tree The phenomenon is the number of entries in one node of details_info tree is less than (max_entries / 3). And it can be easily reproduced by the following procedures: $ new a thin pool $ presume the max entries of details_info tree is 126 $ new 127 thin devices (e.g. 1~127) to make the root node being full and then split $ remove the first 43 (e.g. 1~43) thin devices to make the children reblance repeatedly $ stop the thin pool $ thin_check The root cause is that the B-tree removal procedure in __rebalance2() doesn't guarantee the invariance: the minimal number of entries in non-root node should be >= (max_entries / 3). Simply fix the problem by increasing the rebalance threshold to make sure the number of entries in each child will be greater than or equal to (max_entries / 3 + 1), so no matter which child is used for removal, the number will still be valid. Cc: stable@vger.kernel.org Signed-off-by: Hou Tao <houtao1@huawei.com> Acked-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 |