File 3002-btrfs-progs-Introduce-function-to-fix-super-block-to.patch of Package btrfsprogs.5036
From: Qu Wenruo <wqu@suse.com>
Date: Tue, 17 Oct 2017 15:12:39 +0800
Subject: btrfs-progs: Introduce function to fix super block total bytes
Git-commit: a450dc4bfe76329b908e2b5aa43d3e6a6aa22732
Patch-mainline: v4.14
References: bsc#1083287
Recent kernel (starting from v4.6) will refuse to mount if super block
total bytes is smaller than all devices' size.
This makes end user unable to do anything to their otherwise quite
healthy fs.
To fix such problem, introduce repair function to fix it on an unmounted
filesystem.
Reported-by: Asif Youssuff <yoasif@gmail.com>
Reported-by: Rich Rauenzahn <rrauenza@gmail.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
volumes.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++
volumes.h | 1 +
2 files changed, 53 insertions(+)
Index: btrfs-progs-v4.5.3/volumes.c
===================================================================
--- btrfs-progs-v4.5.3.orig/volumes.c
+++ btrfs-progs-v4.5.3/volumes.c
@@ -2217,3 +2217,55 @@ err:
btrfs_release_path(&path);
return ret;
}
+
+/*
+ * Return 0 if super block total_bytes matches all devices' total_bytes
+ * Return >0 if super block total_bytes mismatch but fixed without problem
+ * Return <0 if we failed to fix super block total_bytes
+ */
+int btrfs_fix_super_size(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_device *device;
+ struct list_head *dev_list = &fs_info->fs_devices->devices;
+ u64 total_bytes = 0;
+ u64 old_bytes = btrfs_super_total_bytes(fs_info->super_copy);
+ u32 sectorsize = fs_info->tree_root->sectorsize;
+ int ret;
+
+ list_for_each_entry(device, dev_list, dev_list) {
+ /*
+ * Caller should ensure this function is called after aligning
+ * all devices' total_bytes.
+ */
+ if (!IS_ALIGNED(device->total_bytes, sectorsize)) {
+ error("device %llu total_bytes %llu not aligned to %u",
+ device->devid, device->total_bytes, sectorsize);
+ return -EUCLEAN;
+ }
+ total_bytes += device->total_bytes;
+ }
+
+ if (total_bytes == old_bytes)
+ return 0;
+
+ btrfs_set_super_total_bytes(fs_info->super_copy, total_bytes);
+
+ /* Commit transaction to update all super blocks */
+ trans = btrfs_start_transaction(fs_info->tree_root, 1);
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ error("error starting transaction: %d (%s)",
+ ret, strerror(-ret));
+ return ret;
+ }
+ ret = btrfs_commit_transaction(trans, fs_info->tree_root);
+ if (ret < 0) {
+ error("failed to commit current transaction: %d (%s)",
+ ret, strerror(-ret));
+ return ret;
+ }
+ printf("Fixed super total bytes, old size: %llu new size: %llu\n",
+ old_bytes, total_bytes);
+ return 1;
+}
Index: btrfs-progs-v4.5.3/volumes.h
===================================================================
--- btrfs-progs-v4.5.3.orig/volumes.h
+++ btrfs-progs-v4.5.3/volumes.h
@@ -228,4 +228,5 @@ int write_raid56_with_parity(struct btrf
u64 stripe_len, u64 *raid_map);
int btrfs_fix_device_size(struct btrfs_fs_info *fs_info,
struct btrfs_device *device);
+int btrfs_fix_super_size(struct btrfs_fs_info *fs_info);
#endif
