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path: root/drivers/md/persistent-data/dm-btree.c
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2015-07-06dm btree: silence lockdep lock inversion in dm_btree_del()Joe Thornber
Allocate memory using GFP_NOIO when deleting a btree. dm_btree_del() can be called via an ioctl and we don't want to recurse into the FS or block layer. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
2014-11-10dm btree: fix a recursion depth bug in btree walking codeJoe Thornber
The walk code was using a 'ro_spine' to hold it's locked btree nodes. But this data structure is designed for the rolling lock scheme, and as such automatically unlocks blocks that are two steps up the call chain. This is not suitable for the simple recursive walk algorithm, which retraces its steps. This code is only used by the persistent array code, which in turn is only used by dm-cache. In order to trigger it you need to have a mapping tree that is more than 2 levels deep; which equates to 8-16 million cache blocks. For instance a 4T ssd with a very small block size of 32k only just triggers this bug. The fix just places the locked blocks on the stack, and stops using the ro_spine altogether. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
2014-01-09dm btree: add dm_btree_find_lowest_keyJoe Thornber
dm_btree_find_lowest_key is the reciprocal of dm_btree_find_highest_key. Factor out common code for dm_btree_find_{highest,lowest}_key. dm_btree_find_lowest_key is needed for an upcoming DM target, as such it is best to get this interface in place. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-08-23dm btree: prefetch child nodes when walking tree for a dm_btree_delJoe Thornber
dm-btree now takes advantage of dm-bufio's ability to prefetch data via dm_bm_prefetch(). Prior to this change many btree node visits were causing a synchronous read. 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>
2013-08-23dm btree: use pop_frame in dm_btree_del to cleanup codeJoe Thornber
Remove a visited leaf straight away from the stack, rather than marking all it's children as visited and letting it get removed on the next iteration. May also offer a micro optimisation in dm_btree_del. 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>
2013-03-01dm persistent data: add btree_walkJoe Thornber
Add dm_btree_walk to iterate through the contents of a btree. This will be used by the dm cache target. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21dm persistent data: fix nested btree deletionJoe Thornber
When deleting nested btrees, the code forgets to delete the innermost btree. The thin-metadata code serendipitously compensates for this by claiming there is one extra layer in the tree. This patch corrects both problems. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21dm persistent data: rename node to btree_nodeMikulas Patocka
This patch fixes a compilation failure on sparc32 by renaming struct node. struct node is already defined in include/linux/node.h. On sparc32, it happens to be included through other dependencies and persistent-data doesn't compile because of conflicting declarations. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-28dm persistent data: remove redundant value_size arg from value_ptrJoe Thornber
Now that the value_size is held within every node of the btrees we can remove this argument from value_ptr(). For the last few months a BUG_ON has been checking this argument is the same as that held in the node. No issues were reported. So this is a safe change. 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>
2011-11-07drivers/md: change module.h -> export.h in persistent-data/dm-*Paul Gortmaker
For the files which are not themselves modular, we can change them to include only the smaller export.h since all they are doing is looking for EXPORT_SYMBOL. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31dm: add persistent data libraryJoe Thornber
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>