From: Su Yue <Damenly_Su@gmx.com>
Date: Fri, 10 Jan 2020 14:11:33 +0200
Subject: btrfs: Factor out metadata_uuid code from find_fsid.
Git-commit: c6730a0e5778bf2d83189f97ab5e3efe61f6aad1
Patch-mainline: v5.6-rc1
References: git-fixes
find_fsid became rather hairy with the introduction of metadata uuid
changing feature. Alleviate this by factoring out the metadata uuid
specific code in a dedicated function which deals with finding
correct fsid for a device with changed uuid.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Su Yue <Damenly_Su@gmx.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
fs/btrfs/volumes.c | 77 +++++++++++++++++++++++++++++-------------------------
1 file changed, 42 insertions(+), 35 deletions(-)
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index d9957688338b..d48274451452 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -441,39 +441,6 @@ 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- * has an outdated pair of fsid/metadata_uuid and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) {
@@ -489,6 +456,47 @@ static noinline struct btrfs_fs_devices *find_fsid(
return NULL;
}
+static struct btrfs_fs_devices *find_fsid_with_metadata_uuid(
+ 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);
+}
+
+
static int
btrfs_get_bdev_and_sb(const char *device_path, fmode_t flags, void *holder,
int flush, struct block_device **bdev,
@@ -744,8 +752,7 @@ static noinline struct btrfs_device *device_list_add(const char *path,
else
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_with_metadata_uuid(disk_super);
} else {
fs_devices = find_fsid(disk_super->fsid, NULL);
}