From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Anand Jain <anand.jain@oracle.com>,
Josef Bacik <josef@toxicpanda.com>,
David Sterba <dsterba@suse.com>, Sasha Levin <sashal@kernel.org>,
clm@fb.com, jbacik@fb.com, linux-btrfs@vger.kernel.org
Subject: [PATCH AUTOSEL 5.15 11/16] btrfs: harden identification of a stale device
Date: Mon, 28 Mar 2022 15:42:54 -0400 [thread overview]
Message-ID: <20220328194300.1586178-11-sashal@kernel.org> (raw)
In-Reply-To: <20220328194300.1586178-1-sashal@kernel.org>
From: Anand Jain <anand.jain@oracle.com>
[ Upstream commit 770c79fb65506fc7c16459855c3839429f46cb32 ]
Identifying and removing the stale device from the fs_uuids list is done
by btrfs_free_stale_devices(). btrfs_free_stale_devices() in turn
depends on device_path_matched() to check if the device appears in more
than one btrfs_device structure.
The matching of the device happens by its path, the device path. However,
when device mapper is in use, the dm device paths are nothing but a link
to the actual block device, which leads to the device_path_matched()
failing to match.
Fix this by matching the dev_t as provided by lookup_bdev() instead of
plain string compare of the device paths.
Reported-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/btrfs/volumes.c | 45 ++++++++++++++++++++++++++++++++++++++-------
1 file changed, 38 insertions(+), 7 deletions(-)
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 06a1a7c2254c..33bd94ee4690 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -530,15 +530,48 @@ btrfs_get_bdev_and_sb(const char *device_path, fmode_t flags, void *holder,
return ret;
}
-static bool device_path_matched(const char *path, struct btrfs_device *device)
+/*
+ * Check if the device in the path matches the device in the given struct device.
+ *
+ * Returns:
+ * true If it is the same device.
+ * false If it is not the same device or on error.
+ */
+static bool device_matched(const struct btrfs_device *device, const char *path)
{
- int found;
+ char *device_name;
+ dev_t dev_old;
+ dev_t dev_new;
+ int ret;
+
+ /*
+ * If we are looking for a device with the matching dev_t, then skip
+ * device without a name (a missing device).
+ */
+ if (!device->name)
+ return false;
+
+ device_name = kzalloc(BTRFS_PATH_NAME_MAX, GFP_KERNEL);
+ if (!device_name)
+ return false;
rcu_read_lock();
- found = strcmp(rcu_str_deref(device->name), path);
+ scnprintf(device_name, BTRFS_PATH_NAME_MAX, "%s", rcu_str_deref(device->name));
rcu_read_unlock();
- return found == 0;
+ ret = lookup_bdev(device_name, &dev_old);
+ kfree(device_name);
+ if (ret)
+ return false;
+
+ ret = lookup_bdev(path, &dev_new);
+ if (ret)
+ return false;
+
+ if (dev_old == dev_new)
+ return true;
+
+ return false;
}
/*
@@ -571,9 +604,7 @@ static int btrfs_free_stale_devices(const char *path,
&fs_devices->devices, dev_list) {
if (skip_device && skip_device == device)
continue;
- if (path && !device->name)
- continue;
- if (path && !device_path_matched(path, device))
+ if (path && !device_matched(device, path))
continue;
if (fs_devices->opened) {
/* for an already deleted device return 0 */
--
2.34.1
next prev parent reply other threads:[~2022-03-28 19:48 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-28 19:42 [PATCH AUTOSEL 5.15 01/16] atomics: Fix atomic64_{read_acquire,set_release} fallbacks Sasha Levin
2022-03-28 19:42 ` [PATCH AUTOSEL 5.15 02/16] locking/lockdep: Iterate lock_classes directly when reading lockdep files Sasha Levin
2022-03-28 19:42 ` [PATCH AUTOSEL 5.15 03/16] ext4: correct cluster len and clusters changed accounting in ext4_mb_mark_bb Sasha Levin
2022-03-28 19:42 ` [PATCH AUTOSEL 5.15 04/16] ext4: fix ext4_mb_mark_bb() with flex_bg with fast_commit Sasha Levin
2022-03-28 19:42 ` [PATCH AUTOSEL 5.15 05/16] sched/tracing: Don't re-read p->state when emitting sched_switch event Sasha Levin
2022-03-28 19:42 ` [PATCH AUTOSEL 5.15 06/16] sched/tracing: Report TASK_RTLOCK_WAIT tasks as TASK_UNINTERRUPTIBLE Sasha Levin
2022-03-28 19:42 ` [PATCH AUTOSEL 5.15 07/16] ext4: don't BUG if someone dirty pages without asking ext4 first Sasha Levin
2022-03-28 19:43 ` syzbot
2022-03-28 19:42 ` [PATCH AUTOSEL 5.15 08/16] f2fs: fix to do sanity check on curseg->alloc_type Sasha Levin
2022-03-28 19:42 ` [PATCH AUTOSEL 5.15 09/16] NFSD: Fix nfsd_breaker_owns_lease() return values Sasha Levin
2022-03-28 19:42 ` [PATCH AUTOSEL 5.15 10/16] f2fs: don't get FREEZE lock in f2fs_evict_inode in frozen fs Sasha Levin
2022-03-28 19:42 ` Sasha Levin [this message]
2022-03-28 19:42 ` [PATCH AUTOSEL 5.15 12/16] btrfs: make search_csum_tree return 0 if we get -EFBIG Sasha Levin
2022-03-28 19:42 ` [PATCH AUTOSEL 5.15 13/16] f2fs: use spin_lock to avoid hang Sasha Levin
2022-03-28 19:42 ` [PATCH AUTOSEL 5.15 14/16] f2fs: compress: fix to print raw data size in error path of lz4 decompression Sasha Levin
2022-03-28 19:42 ` [PATCH AUTOSEL 5.15 15/16] Adjust cifssb maximum read size Sasha Levin
2022-03-28 19:42 ` [PATCH AUTOSEL 5.15 16/16] ntfs: add sanity check on allocation size Sasha Levin
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