For an extent item which contains many tree block backrefs, like
In 020-extent-ref-cases/keyed_block_ref.img
item 10 key (29470720 METADATA_ITEM 0) itemoff 3450 itemsize 222
refs 23 gen 10 flags TREE_BLOCK
tree block skinny level 0
tree block backref root 278
tree block backref root 277
tree block backref root 276
tree block backref root 275
tree block backref root 274
tree block backref root 273
tree block backref root 272
tree block backref root 271
tree block backref root 270
tree block backref root 269
tree block backref root 268
tree block backref root 267
tree block backref root 266
tree block backref root 265
tree block backref root 264
tree block backref root 263
tree block backref root 262
tree block backref root 261
tree block backref root 260
tree block backref root 259
tree block backref root 258
tree block backref root 257
In find_parent_nodes(), these refs's parents are 0, then __merge_refs
will merge refs to one ref. It causes only one root to be returned.
So, if both parents are 0, do not merge refs.
Lowmem check calls find_parent_nodes frequently to decide whether
check an extent buffer or not. The bug affects bytes accounting.
Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
After call of ref_for_same_block, ref1->parent must equals to
ref2->parent, the block of exchange is never reached.
So remove the block of exchange.
Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There is no delayed ref in btrfs-progs, so remove related comments.
Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
Btrfs lowmem mode fails with the following ASSERT() on certain valid
image.
------
backref.c:466: __add_missing_keys: Assertion `ref->root_id` failed, value 0
------
[REASON]
Lowmem mode uses btrfs_find_all_roots() when walking down fs trees.
However if a tree block with only shared parent backref like below,
backref code from btrfs-progs doesn't handle it correct.
------
item 72 key (604653731840 METADATA_ITEM 0) itemoff 13379 itemsize 60
refs 4 gen 7198 flags TREE_BLOCK|FULL_BACKREF
tree block skinny level 0
shared block backref parent 604498477056
shared block backref parent 604498460672
shared block backref parent 604498444288
shared block backref parent 604498411520
------
Such shared block ref is *direct* ref, which means we don't need to
solve its key, nor its rootid.
As the objective of backref walk is to find all direct parents until it
reaches tree root.
So for such direct ref, it should be pended to pref_stat->pending, other
than pending it to pref_stat->pending_missing_key.
[FIX]
For direct ref, pending it to pref_state->pending directly to solve the
problem.
Reported-by: Chris Murphy <chris@colorremedies.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Rather than iterate over all outstanding backrefs to resolve indirect refs,
use a separate list that only contains indirect refs.
When we process missing keys, the ref moves to the indirect ref list.
Once the indirect ref is resolved, move the ref to the pending list.
Eventually these lists will be replaced by rbtrees.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
[ added assertion fix from Josef ]
Signed-off-by: David Sterba <dsterba@suse.com>
Rather than iterate over all outstanding backrefs to resolve missing keys,
use a separate list that only contains refs that need missing keys resolved.
Once the missing key is resolved, move the ref to the pending list.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Eventually, we'll have several lists and trees, as well as some statistics.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The only reasom read_tree_block() needs a btrfs_root parameter is to get
its node/sector size.
And long ago, I have already introduced a compactible interface,
read_tree_block_fs_info() to pass btrfs_fs_info instead of btrfs_root.
Since we have cleaned up all root->sector/node/stripesize users, we
should be OK to refactor read_tree_block() function.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
The implementation of ulist_* is same for kernel and userspace, without
dependencies, so we can keep it separately for code sync.
Signed-off-by: David Sterba <dsterba@suse.com>
Nodesize is used in kernel, the values are always equal. We have to keep
leafsize in headers, similarly the tree setting functions still take and
set leafsize, but it's effectively a no-op.
Signed-off-by: David Sterba <dsterba@suse.com>
kerncompat.h header file is part of libbtrfs API. min/max macros cause
conflict while building projects dependant on libbtrfs. Moving those
macros to btrfs-progs internal header file fixes the conflict.
Signed-off-by: Ondrej Kozina <okozina@redhat.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Coverity reports execution cannot reach this statements. So put WARN_ON
in if-else conditions.
Signed-off-by: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Allow read_tree_block() and read_node_slot() to return error pointer.
This should help caller to get more specified error number.
For existing callers, change (!eb) judgmentt to
(!extent_buffer_uptodate(eb)) to keep the compatibility, and for caller
missing the check, use PTR_ERR(eb) if possible.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
This patch pulls back backref.c, adds a couple of helpers everywhere that it
needs, and cleans up backref.c to fit in btrfs-progs. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
[removed free_some_buffers after "do not reclaim extent buffer"]
Signed-off-by: David Sterba <dsterba@suse.cz>
