On 2019/12/12 9:05 PM, Nikolay Borisov wrote:
On 12.12.19 г. 13:01 ч., damenly.su@xxxxxxxxx wrote:
From: Su Yue <Damenly_Su@xxxxxxx>
The parameter @metadata_fsid of fs_id() is not NULL while scanned device
has metadata_uuid but not changing. Obviously, the cases handling part
in fs_id() is for this situation. Move the logic into new function
find_fsid_changing_metadata_uuid().
I think the following changelog might sound better.
metadata_fsid parameter of find_fsid is non-null in once specific case
in device_list_add. Factor the code out of find_fsid to a dedicated
function to improve readability.
Thanks for the changelog! will replace.
Signed-off-by: Su Yue <Damenly_Su@xxxxxxx>
---
fs/btrfs/volumes.c | 78 ++++++++++++++++++++++++----------------------
1 file changed, 41 insertions(+), 37 deletions(-)
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 9efa4123c335..b08b06a89a77 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -438,40 +438,6 @@ static noinline struct btrfs_fs_devices *find_fsid(
ASSERT(fsid);
- if (metadata_fsid) {
- /*
- * Handle scanned device having completed its fsid change but
- * belonging to a fs_devices that was created by first scanning
- * a device which didn't have its fsid/metadata_uuid changed
- * at all and the CHANGING_FSID_V2 flag set.
- */
- list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
- if (fs_devices->fsid_change &&
- memcmp(metadata_fsid, fs_devices->fsid,
- BTRFS_FSID_SIZE) == 0 &&
- memcmp(fs_devices->fsid, fs_devices->metadata_uuid,
- BTRFS_FSID_SIZE) == 0) {
- return fs_devices;
- }
- }
- /*
- * Handle scanned device having completed its fsid change but
- * belonging to a fs_devices that was created by a device that
- * has an outdated pair of fsid/metadata_uuid and
- * CHANGING_FSID_V2 flag set.
- */
- list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
- if (fs_devices->fsid_change &&
- memcmp(fs_devices->metadata_uuid,
- fs_devices->fsid, BTRFS_FSID_SIZE) != 0 &&
- memcmp(metadata_fsid, fs_devices->metadata_uuid,
- BTRFS_FSID_SIZE) == 0) {
- return fs_devices;
- }
- }
- }
-
- /* Handle non-split brain cases */
list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
if (metadata_fsid) {
if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0
@@ -712,6 +678,46 @@ static struct btrfs_fs_devices *find_fsid_changed(
return NULL;
}
+
+static struct btrfs_fs_devices *find_fsid_changing_metada_uuid(
That function name is long (and contains a typo). More like something like:
find_fsid_with_metadata_uuid.
Fine. Naming is so hard to me.
Thanks.
+ struct btrfs_super_block *disk_super)
+{
+ struct btrfs_fs_devices *fs_devices;
+
+ /*
+ * Handle scanned device having completed its fsid change but
+ * belonging to a fs_devices that was created by first scanning
+ * a device which didn't have its fsid/metadata_uuid changed
+ * at all and the CHANGING_FSID_V2 flag set.
+ */
+ list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
+ if (fs_devices->fsid_change &&
+ memcmp(disk_super->metadata_uuid, fs_devices->fsid,
+ BTRFS_FSID_SIZE) == 0 &&
+ memcmp(fs_devices->fsid, fs_devices->metadata_uuid,
+ BTRFS_FSID_SIZE) == 0) {
+ return fs_devices;
+ }
+ }
+ /*
+ * Handle scanned device having completed its fsid change but
+ * belonging to a fs_devices that was created by a device that
+ * has an outdated pair of fsid/metadata_uuid and
+ * CHANGING_FSID_V2 flag set.
+ */
+ list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
+ if (fs_devices->fsid_change &&
+ memcmp(fs_devices->metadata_uuid,
+ fs_devices->fsid, BTRFS_FSID_SIZE) != 0 &&
+ memcmp(disk_super->metadata_uuid, fs_devices->metadata_uuid,
+ BTRFS_FSID_SIZE) == 0) {
+ return fs_devices;
+ }
+ }
+
+ return find_fsid(disk_super->fsid, disk_super->metadata_uuid);
+}
+
/*
* Add new device to list of registered devices
*
@@ -751,13 +757,11 @@ static noinline struct btrfs_device *device_list_add(const char *path,
fs_devices = find_fsid_changed(disk_super);
}
} else if (has_metadata_uuid) {
- fs_devices = find_fsid(disk_super->fsid,
- disk_super->metadata_uuid);
+ fs_devices = find_fsid_changing_metada_uuid(disk_super);
} else {
fs_devices = find_fsid(disk_super->fsid, NULL);
}
-
if (!fs_devices) {
if (has_metadata_uuid)
fs_devices = alloc_fs_devices(disk_super->fsid,
