x86/amd_node: Fix PCI device reference counting in amd_smn_init()grafted

The local "root" pointer is a temporary variable used during the device
search. Therefore, refcount related to the search iterators should be cleaned
up after the search is complete.

Use the __free() cleanup macro to ensure the refcount is decremented when the
temporary pointer goes out of scope.

Additionally, increment the refcount when caching a root pointer. This ensures
the in-use refcount is separate from the temporary search refcounting.

Finally, drop the redundant "root = NULL" before the second search loop. The
pci_get_class() iterator always decrements the refcount of its "from"
argument, so the first loop can only fall through with "root" already NULL.

Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching")
Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com
Reported-by: Sashiko <sashiko-bot@kernel.org>
Assisted-by: LLM
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Cc: <stable@kernel.org>
Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com

1 files changed, 31 insertions, 0 deletions

diff --git a/fs/btrfs/delalloc-space.h b/fs/btrfs/delalloc-space.h
new file mode 100644
index 000000000..6119c0d3f
--- /dev/null
+++ b/fs/btrfs/delalloc-space.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef BTRFS_DELALLOC_SPACE_H
+#define BTRFS_DELALLOC_SPACE_H
+
+#include <linux/types.h>
+
+struct extent_changeset;
+struct btrfs_inode;
+struct btrfs_fs_info;
+
+int btrfs_alloc_data_chunk_ondemand(const struct btrfs_inode *inode, u64 bytes);
+int btrfs_check_data_free_space(struct btrfs_inode *inode,
+			struct extent_changeset **reserved, u64 start, u64 len,
+			bool noflush);
+void btrfs_free_reserved_data_space(struct btrfs_inode *inode,
+			struct extent_changeset *reserved, u64 start, u64 len);
+void btrfs_delalloc_release_space(struct btrfs_inode *inode,
+				  struct extent_changeset *reserved,
+				  u64 start, u64 len, bool qgroup_free);
+void btrfs_free_reserved_data_space_noquota(struct btrfs_inode *inode, u64 len);
+void btrfs_delalloc_release_metadata(struct btrfs_inode *inode, u64 num_bytes,
+				     bool qgroup_free);
+int btrfs_delalloc_reserve_space(struct btrfs_inode *inode,
+			struct extent_changeset **reserved, u64 start, u64 len);
+int btrfs_delalloc_reserve_metadata(struct btrfs_inode *inode, u64 num_bytes,
+				    u64 disk_num_bytes, bool noflush);
+void btrfs_delalloc_release_extents(struct btrfs_inode *inode, u64 num_bytes);
+void btrfs_delalloc_shrink_extents(struct btrfs_inode *inode, u64 reserved_len, u64 new_len);
+
+#endif /* BTRFS_DELALLOC_SPACE_H */