From: David Howells <dhowells@redhat.com>
To: linux-afs@lists.infradead.org
Cc: dhowells@redhat.com, linux-kernel@vger.kernel.org
Subject: [PATCH 04/15] afs: Fix missing lock when replacing VL server list
Date: Wed, 15 May 2019 17:26:06 +0100 [thread overview]
Message-ID: <155793756678.31671.3057069610724058972.stgit@warthog.procyon.org.uk> (raw)
In-Reply-To: <155793753724.31671.7034451837854752319.stgit@warthog.procyon.org.uk>
When afs_update_cell() replaces the cell->vl_servers list, it uses RCU
protocol so that proc is protected, but doesn't take ->vl_servers_lock to
protect afs_start_vl_iteration() (which does actually take a shared lock).
Fix this by making afs_update_cell() take an exclusive lock when replacing
->vl_servers.
Fixes: 0a5143f2f89c ("afs: Implement VL server rotation")
Signed-off-by: David Howells <dhowells@redhat.com>
---
fs/afs/cell.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/fs/afs/cell.c b/fs/afs/cell.c
index 9de46116c749..9ca075e11239 100644
--- a/fs/afs/cell.c
+++ b/fs/afs/cell.c
@@ -404,12 +404,11 @@ static void afs_update_cell(struct afs_cell *cell)
clear_bit(AFS_CELL_FL_DNS_FAIL, &cell->flags);
clear_bit(AFS_CELL_FL_NOT_FOUND, &cell->flags);
- /* Exclusion on changing vl_addrs is achieved by a
- * non-reentrant work item.
- */
+ write_lock(&cell->vl_servers_lock);
old = rcu_dereference_protected(cell->vl_servers, true);
rcu_assign_pointer(cell->vl_servers, vllist);
cell->dns_expiry = expiry;
+ write_unlock(&cell->vl_servers_lock);
if (old)
afs_put_vlserverlist(cell->net, old);
next prev parent reply other threads:[~2019-05-15 16:26 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-15 16:25 [PATCH 00/15] AFS fixes David Howells
2019-05-15 16:25 ` [PATCH 01/15] afs: Fix key leak in afs_release() and afs_evict_inode() David Howells
2019-05-15 16:25 ` [PATCH 02/15] afs: Fix incorrect error handling in afs_xattr_get_acl() David Howells
2019-05-15 16:26 ` [PATCH 03/15] afs: Fix afs_xattr_get_yfs() to not try freeing an error value David Howells
2019-05-15 16:26 ` David Howells [this message]
2019-05-15 16:26 ` [PATCH 05/15] afs: Fix afs_cell records to always have a VL server list record David Howells
2019-05-15 16:26 ` [PATCH 06/15] dns_resolver: Allow used keys to be invalidated David Howells
2019-05-15 16:26 ` [PATCH 07/15] Add wait_var_event_interruptible() David Howells
2019-05-15 17:30 ` Peter Zijlstra
2019-05-15 16:26 ` [PATCH 08/15] afs: Fix cell DNS lookup David Howells
2019-05-15 16:26 ` [PATCH 09/15] rxrpc: Allow the kernel to mark a call as being non-interruptible David Howells
2019-05-15 16:26 ` [PATCH 10/15] afs: Make some RPC operations non-interruptible David Howells
2019-05-15 16:26 ` [PATCH 11/15] afs: Make dynamic root population wait uninterruptibly for proc_cells_lock David Howells
2019-05-15 16:27 ` [PATCH 12/15] afs: Fix calculation of callback expiry time David Howells
2019-05-15 16:27 ` [PATCH 13/15] afs: Don't invalidate callback if AFS_VNODE_DIR_VALID not set David Howells
2019-05-15 16:27 ` [PATCH 14/15] afs: Fix lock-wait/callback-break double locking David Howells
2019-05-15 16:27 ` [PATCH 15/15] afs: Fix double inc of vnode->cb_break 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=155793756678.31671.3057069610724058972.stgit@warthog.procyon.org.uk \
--to=dhowells@redhat.com \
--cc=linux-afs@lists.infradead.org \
--cc=linux-kernel@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).