From: Josef Bacik <josef@toxicpanda.com>
To: linux-btrfs@vger.kernel.org, kernel-team@fb.com
Subject: [PATCH v2 1/5] btrfs: fix reloc root leak with 0 ref reloc roots on recovery
Date: Thu, 14 Jan 2021 14:02:42 -0500 [thread overview]
Message-ID: <aa39cd6739424107752368ca4911b605b64eac07.1610650736.git.josef@toxicpanda.com> (raw)
In-Reply-To: <cover.1610650736.git.josef@toxicpanda.com>
When recovering a relocation, if we run into a reloc root that has 0
refs we simply add it to the reloc_control->reloc_roots list, and then
clean it up later. The problem with this is __del_reloc_root() doesn't
do anything if the root isn't in the radix tree, which in this case it
won't be because we never call __add_reloc_root() on the reloc_root.
This exit condition simply isn't correct really. During normal
operation we can remove ourselves from the rb tree and then we're meant
to clean up later at merge_reloc_roots() time, and this happens
correctly. During recovery we're depending on free_reloc_roots() to
drop our references, but we're short-circuiting.
Fix this by continuing to check if we're on the list and dropping
ourselves from the reloc_control root list and dropping our reference
appropriately. Change the corresponding BUG_ON() to an ASSERT() that
does the correct thing if we aren't in the rb tree.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
fs/btrfs/relocation.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 9f2289bcdde6..d29baf3822a7 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -669,9 +669,7 @@ static void __del_reloc_root(struct btrfs_root *root)
RB_CLEAR_NODE(&node->rb_node);
}
spin_unlock(&rc->reloc_root_tree.lock);
- if (!node)
- return;
- BUG_ON((struct btrfs_root *)node->data != root);
+ ASSERT(!node || (struct btrfs_root *)node->data == root);
}
/*
--
2.26.2
next prev parent reply other threads:[~2021-01-14 19:03 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-14 19:02 [PATCH v2 0/5] Serious fixes for different error paths Josef Bacik
2021-01-14 19:02 ` Josef Bacik [this message]
2021-01-14 19:02 ` [PATCH v2 2/5] btrfs: splice remaining dirty_bg's onto the transaction dirty bg list Josef Bacik
2021-01-14 19:02 ` [PATCH v2 3/5] btrfs: do not WARN_ON() if we can't find the reloc root Josef Bacik
2021-01-14 19:02 ` [PATCH v2 4/5] btrfs: add asserts for deleting backref cache nodes Josef Bacik
2021-01-14 19:02 ` [PATCH v2 5/5] btrfs: abort the transaction if we fail to inc ref in btrfs_copy_root Josef Bacik
2021-01-26 16:41 ` [PATCH v2 0/5] Serious fixes for different error paths David Sterba
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=aa39cd6739424107752368ca4911b605b64eac07.1610650736.git.josef@toxicpanda.com \
--to=josef@toxicpanda.com \
--cc=kernel-team@fb.com \
--cc=linux-btrfs@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).