From: David Howells <dhowells@redhat.com>
To: linux-afs@lists.infradead.org
Cc: Marc Dionne <marc.dionne@auristor.com>,
dhowells@redhat.com, markus.suvanto@gmail.com,
Marc Dionne <marc.dionne@auristor.com>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 1/6] afs: Fix missing put on afs_read objects and missing get on the key therein
Date: Wed, 08 Sep 2021 16:57:39 +0100 [thread overview]
Message-ID: <163111665914.283156.3038561975681836591.stgit@warthog.procyon.org.uk> (raw)
In-Reply-To: <163111665183.283156.17200205573146438918.stgit@warthog.procyon.org.uk>
The afs_read objects created by afs_req_issue_op() get leaked because
afs_alloc_read() returns a ref and then afs_fetch_data() gets its own ref
which is released when the operation completes, but the initial ref is
never released.
Fix this by discarding the initial ref at the end of afs_req_issue_op().
This leak also covered another bug whereby a ref isn't got on the key
attached to the read record by afs_req_issue_op(). This isn't a problem as
long as the afs_read req never goes away...
Fix this by calling key_get() in afs_req_issue_op().
This was found by the generic/074 test. It leaks a bunch of kmalloc-192
objects each time it is run, which can be observed by watching
/proc/slabinfo.
Fixes: f7605fa869cf ("afs: Fix leak of afs_read objects")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/163010394740.3035676.8516846193899793357.stgit@warthog.procyon.org.uk/
---
fs/afs/file.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/afs/file.c b/fs/afs/file.c
index db035ae2a134..6688fff14b0b 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -295,7 +295,7 @@ static void afs_req_issue_op(struct netfs_read_subrequest *subreq)
fsreq->subreq = subreq;
fsreq->pos = subreq->start + subreq->transferred;
fsreq->len = subreq->len - subreq->transferred;
- fsreq->key = subreq->rreq->netfs_priv;
+ fsreq->key = key_get(subreq->rreq->netfs_priv);
fsreq->vnode = vnode;
fsreq->iter = &fsreq->def_iter;
@@ -304,6 +304,7 @@ static void afs_req_issue_op(struct netfs_read_subrequest *subreq)
fsreq->pos, fsreq->len);
afs_fetch_data(fsreq->vnode, fsreq);
+ afs_put_read(fsreq);
}
static int afs_symlink_readpage(struct page *page)
next prev parent reply other threads:[~2021-09-08 15:57 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-08 15:57 [PATCH 0/6] afs: Fixes for 3rd party-induced data corruption David Howells
2021-09-08 15:57 ` David Howells [this message]
2021-09-10 21:10 ` [PATCH 1/6] afs: Fix missing put on afs_read objects and missing get on the key therein Marc Dionne
2021-09-08 15:57 ` [PATCH 2/6] afs: Fix page leak David Howells
2021-09-08 20:37 ` Marc Dionne
2021-09-08 15:57 ` [PATCH 3/6] afs: Add missing vnode validation checks David Howells
2021-09-08 15:58 ` [PATCH 4/6] afs: Fix incorrect triggering of sillyrename on 3rd-party invalidation David Howells
2021-09-08 15:58 ` [PATCH 5/6] afs: Fix mmap coherency vs 3rd-party changes David Howells
2021-09-08 15:58 ` [PATCH 6/6] afs: Try to avoid taking RCU read lock when checking vnode validity David Howells
2021-09-09 7:40 ` [PATCH 0/6] afs: Fixes for 3rd party-induced data corruption markus.suvanto
2021-09-10 21:19 ` [PATCH 7/6] afs: Fix corruption in reads at fpos 2G-4G from an OpenAFS server David Howells
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=163111665914.283156.3038561975681836591.stgit@warthog.procyon.org.uk \
--to=dhowells@redhat.com \
--cc=linux-afs@lists.infradead.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=marc.dionne@auristor.com \
--cc=markus.suvanto@gmail.com \
/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).