Merge tag 'for-6.19-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:

 - protect reading super block vs setting block size externally (found
   by syzbot)

 - make sure no transaction is started in read-only mode even with some
   rescue mount option combinations

 - fix checksum calculation of backup super blocks when block-group-tree
   is enabled

 - more extensive mount-time checks of device items that could be left
   after device replace and attempting degraded mount

 - fix build warning with -Wmaybe-uninitialized on loongarch64-gcc 12

* tag 'for-6.19-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: add extra device item checks at mount
  btrfs: fix missing fields in superblock backup with BLOCK_GROUP_TREE
  btrfs: reject new transactions if the fs is fully read-only
  btrfs: sync read disk super and set block size
  btrfs: fix Wmaybe-uninitialized warning in replay_one_buffer()

Author: torvalds

fs/btrfs/disk-io.c

@@ -1661,7 +1661,7 @@ static void backup_super_roots(struct btrfs_fs_info *info)
 	btrfs_set_backup_chunk_root_level(root_backup,
 			       btrfs_header_level(info->chunk_root->node));
 
-	if (!btrfs_fs_compat_ro(info, BLOCK_GROUP_TREE)) {
+	if (!btrfs_fs_incompat(info, EXTENT_TREE_V2)) {
 		struct btrfs_root *extent_root = btrfs_extent_root(info, 0);
 		struct btrfs_root *csum_root = btrfs_csum_root(info, 0);
 
@@ -3255,6 +3255,15 @@ int btrfs_check_features(struct btrfs_fs_info *fs_info, bool is_rw_mount)
 	return 0;
 }
 
+static bool fs_is_full_ro(const struct btrfs_fs_info *fs_info)
+{
+	if (!sb_rdonly(fs_info->sb))
+		return false;
+	if (unlikely(fs_info->mount_opt & BTRFS_MOUNT_FULL_RO_MASK))
+		return true;
+	return false;
+}
+
 int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_devices)
 {
 	u32 sectorsize;
@@ -3363,6 +3372,10 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device
 	if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_ERROR)
 		WRITE_ONCE(fs_info->fs_error, -EUCLEAN);
 
+	/* If the fs has any rescue options, no transaction is allowed. */
+	if (fs_is_full_ro(fs_info))
+		WRITE_ONCE(fs_info->fs_error, -EROFS);
+
 	/* Set up fs_info before parsing mount options */
 	nodesize = btrfs_super_nodesize(disk_super);
 	sectorsize = btrfs_super_sectorsize(disk_super);
@@ -3489,6 +3502,10 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device
 	    fs_info->generation == btrfs_super_uuid_tree_generation(disk_super))
 		set_bit(BTRFS_FS_UPDATE_UUID_TREE_GEN, &fs_info->flags);
 
+	if (unlikely(btrfs_verify_dev_items(fs_info))) {
+		ret = -EUCLEAN;
+		goto fail_block_groups;
+	}
 	ret = btrfs_verify_dev_extents(fs_info);
 	if (ret) {
 		btrfs_err(fs_info,

fs/btrfs/fs.h

@@ -264,6 +264,14 @@ enum {
 	BTRFS_MOUNT_REF_TRACKER			= (1ULL << 33),
 };
 
+/* These mount options require a full read-only fs, no new transaction is allowed. */
+#define BTRFS_MOUNT_FULL_RO_MASK		\
+	(BTRFS_MOUNT_NOLOGREPLAY |		\
+	 BTRFS_MOUNT_IGNOREBADROOTS |		\
+	 BTRFS_MOUNT_IGNOREDATACSUMS |		\
+	 BTRFS_MOUNT_IGNOREMETACSUMS |		\
+	 BTRFS_MOUNT_IGNORESUPERFLAGS)
+
 /*
  * Compat flags that we support.  If any incompat flags are set other than the
  * ones specified below then we will fail to mount

fs/btrfs/tree-log.c

@@ -2798,7 +2798,7 @@ static int replay_one_buffer(struct extent_buffer *eb,
 
 	nritems = btrfs_header_nritems(eb);
 	for (wc->log_slot = 0; wc->log_slot < nritems; wc->log_slot++) {
-		struct btrfs_inode_item *inode_item;
+		struct btrfs_inode_item *inode_item = NULL;
 
 		btrfs_item_key_to_cpu(eb, &wc->log_key, wc->log_slot);
 

fs/btrfs/volumes.c

@@ -1364,7 +1364,9 @@ struct btrfs_super_block *btrfs_read_disk_super(struct block_device *bdev,
 				      (bytenr + BTRFS_SUPER_INFO_SIZE) >> PAGE_SHIFT);
 	}
 
+	filemap_invalidate_lock(mapping);
 	page = read_cache_page_gfp(mapping, bytenr >> PAGE_SHIFT, GFP_NOFS);
+	filemap_invalidate_unlock(mapping);
 	if (IS_ERR(page))
 		return ERR_CAST(page);
 
@@ -7257,6 +7259,7 @@ static int read_one_dev(struct extent_buffer *leaf,
 			return -EINVAL;
 		}
 	}
+	set_bit(BTRFS_DEV_STATE_ITEM_FOUND, &device->dev_state);
 	set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
 	if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) &&
 	   !test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
@@ -8082,6 +8085,45 @@ int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info)
 	return verify_chunk_dev_extent_mapping(fs_info);
 }
 
+/*
+ * Ensure that all devices registered in the fs have their device items in the
+ * chunk tree.
+ *
+ * Return true if unexpected device is found.
+ * Return false otherwise.
+ */
+bool btrfs_verify_dev_items(const struct btrfs_fs_info *fs_info)
+{
+	struct btrfs_fs_devices *seed_devs;
+	struct btrfs_device *dev;
+	bool ret = false;
+
+	mutex_lock(&uuid_mutex);
+	list_for_each_entry(dev, &fs_info->fs_devices->devices, dev_list) {
+		if (!test_bit(BTRFS_DEV_STATE_ITEM_FOUND, &dev->dev_state)) {
+			btrfs_err(fs_info,
+			"devid %llu path %s is registered but not found in chunk tree",
+				  dev->devid, btrfs_dev_name(dev));
+			ret = true;
+		}
+	}
+	list_for_each_entry(seed_devs, &fs_info->fs_devices->seed_list, seed_list) {
+		list_for_each_entry(dev, &seed_devs->devices, dev_list) {
+			if (!test_bit(BTRFS_DEV_STATE_ITEM_FOUND, &dev->dev_state)) {
+				btrfs_err(fs_info,
+			"devid %llu path %s is registered but not found in chunk tree",
+					  dev->devid, btrfs_dev_name(dev));
+				ret = true;
+			}
+		}
+	}
+	mutex_unlock(&uuid_mutex);
+	if (ret)
+		btrfs_err(fs_info,
+"remove the above devices or use 'btrfs device scan --forget <dev>' to unregister them before mount");
+	return ret;
+}
+
 /*
  * Check whether the given block group or device is pinned by any inode being
  * used as a swapfile.

fs/btrfs/volumes.h

@@ -100,6 +100,9 @@ enum btrfs_raid_types {
 #define BTRFS_DEV_STATE_FLUSH_SENT	(4)
 #define BTRFS_DEV_STATE_NO_READA	(5)
 
+/* Set when the device item is found in chunk tree, used to catch unexpected registered device. */
+#define BTRFS_DEV_STATE_ITEM_FOUND	(7)
+
 /* Special value encoding failure to write primary super block. */
 #define BTRFS_SUPER_PRIMARY_WRITE_ERROR		(INT_MAX / 2)
 
@@ -893,6 +896,7 @@ enum btrfs_raid_types __attribute_const__ btrfs_bg_flags_to_raid_index(u64 flags
 int btrfs_bg_type_to_factor(u64 flags);
 const char *btrfs_bg_type_to_raid_name(u64 flags);
 int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info);
+bool btrfs_verify_dev_items(const struct btrfs_fs_info *fs_info);
 bool btrfs_repair_one_zone(struct btrfs_fs_info *fs_info, u64 logical);
 
 bool btrfs_pinned_by_swapfile(struct btrfs_fs_info *fs_info, void *ptr);