5.4-stable patches

added patches:
	btrfs-harden-identification-of-a-stale-device.patch

diff --git a/queue-5.4/btrfs-harden-identification-of-a-stale-device.patch b/queue-5.4/btrfs-harden-identification-of-a-stale-device.patch
new file mode 100644 (file)
index 0000000..f854cdc
--- /dev/null
+++ b/queue-5.4/btrfs-harden-identification-of-a-stale-device.patch
@@ -0,0 +1,95 @@
+From 770c79fb65506fc7c16459855c3839429f46cb32 Mon Sep 17 00:00:00 2001
+From: Anand Jain <anand.jain@oracle.com>
+Date: Wed, 12 Jan 2022 13:05:59 +0800
+Subject: btrfs: harden identification of a stale device
+
+From: Anand Jain <anand.jain@oracle.com>
+
+commit 770c79fb65506fc7c16459855c3839429f46cb32 upstream.
+
+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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ fs/btrfs/volumes.c |   44 +++++++++++++++++++++++++++++++++++++-------
+ 1 file changed, 37 insertions(+), 7 deletions(-)
+
+--- a/fs/btrfs/volumes.c
++++ b/fs/btrfs/volumes.c
+@@ -713,15 +713,47 @@ static void pending_bios_fn(struct btrfs
+       run_scheduled_bios(device);
+ }
+ 
+-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;
++      struct block_device *bdev_old;
++      struct block_device *bdev_new;
++
++      /*
++       * 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;
++      bdev_old = lookup_bdev(device_name);
++      kfree(device_name);
++      if (IS_ERR(bdev_old))
++              return false;
++
++      bdev_new = lookup_bdev(path);
++      if (IS_ERR(bdev_new))
++              return false;
++
++      if (bdev_old == bdev_new)
++              return true;
++
++      return false;
+ }
+ 
+ /*
+@@ -754,9 +786,7 @@ static int btrfs_free_stale_devices(cons
+                                        &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 */

diff --git a/queue-5.4/series b/queue-5.4/series
index b902bccd1718c0fd7f4aac13c093579f28fd1e08..4eef5c29eb2e9890c32691dc60ba9311754e1bcd 100644 (file)
--- a/queue-5.4/series
+++ b/queue-5.4/series
@@ -53,3 +53,4 @@ net-mac802154-fix-a-condition-in-the-receive-path.patch
 alsa-seq-oss-fix-data-race-for-max_midi_devs-access.patch
 alsa-seq-fix-data-race-at-module-auto-loading.patch
 drm-i915-glk-ecs-liva-q2-needs-glk-hdmi-port-timing-quirk.patch
+btrfs-harden-identification-of-a-stale-device.patch