Matthew Ahrens a57f954226 zdb leak detection fails with in-progress device removal ... When a device removal is in progress, there are 2 locations for the data that's already been moved: the original location, on the device that's being removed; and the new location, which is pointed to by the indirect mapping. When doing leak detection, zdb needs to know about both locations. To determine what's already been copied, we load the spacemaps of the removing vdev, omit the blocks that are yet to be copied, and then use the vdev's remap op to find the new location. The problem is with an optimization to the spacemap-loading code in zdb. When processing the log spacemaps, we ignore entries that are not relevant because they are past the point that's been copied. However, entries which span the point that's been copied (i.e. they are partly relevant and partly irrelevant) are processed normally. This can lead to an illegal spacemap operation, for example if offsets up to 100KB have been copied, and the spacemap log has the following entries: ALLOC 50KB-150KB (partly relevant) FREE 50KB-100KB (entirely relevant) FREE 100KB-150KB (entirely irrlevant - ignored) ALLOC 50KB-150KB (partly relevant) Because the entirely irrelevant entry was ignored, its space remains in the spacemap. When the last entry is processed, we attempt to add it to the spacemap, but it partially overlaps with the 100-150KB entry that was left over. This problem was discovered by ztest/zloop. One solution would be to also ignore the irrelevant parts of partially-irrelevant entries (i.e. when processing the ALLOC 50-150, to only add 50-100 to the spacemap). However, this commit implements a simpler solution, which is to remove this optimization entirely. I.e. to process the entire spacemap log, without regard for the point that's been copied. After reconstructing the entire allocatable range tree, there's already code to remove the parts that have not yet been copied. Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Matthew Ahrens <mahrens@delphix.com> External-issue: DLPX-71820 Closes #10920		2020-09-17 10:55:30 -07:00
..
.gitignore	Add .gitignore files to exclude build products	2010-01-08 11:35:17 -08:00
Makefile.am	Unconditionally enable debugging for libzpool	2020-07-10 15:30:31 -07:00
zdb_il.c	OpenZFS 9166 - zfs storage pool checkpoint	2018-06-26 10:07:42 -07:00
zdb.c	zdb leak detection fails with in-progress device removal	2020-09-17 10:55:30 -07:00
zdb.h	OpenZFS 8081 - Compiler warnings in zdb	2017-10-27 12:46:35 -07:00