Commit Graph

9 Commits

Author SHA1 Message Date
Joe Thornber f164e6900f dm btree: add dm_btree_find_lowest_key
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>
2014-01-09 16:29:17 -05:00
Joe Thornber 04f17c802f dm btree: prefetch child nodes when walking tree for a dm_btree_del
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>
2013-08-23 09:02:14 -04:00
Joe Thornber cd5acf0b44 dm btree: use pop_frame in dm_btree_del to cleanup code
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>
2013-08-23 09:02:14 -04:00
Joe Thornber 4e7f1f9089 dm persistent data: add btree_walk
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>
2013-03-01 22:45:50 +00:00
Joe Thornber e3cbf94513 dm persistent data: fix nested btree deletion
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>
2012-12-21 20:23:32 +00:00
Mikulas Patocka 550929faf8 dm persistent data: rename node to btree_node
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>
2012-12-21 20:23:30 +00:00
Joe Thornber a3aefb395e dm persistent data: remove redundant value_size arg from value_ptr
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>
2012-03-28 18:41:25 +01:00
Paul Gortmaker 1944ce60fe drivers/md: change module.h -> export.h in persistent-data/dm-*
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>
2011-11-07 10:29:09 -08:00
Joe Thornber 3241b1d3e0 dm: add persistent data library
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>
2011-10-31 20:19:11 +00:00