ANDROID: GKI: fs.h: add Android ABI padding to some structures

Try to mitigate potential future driver core api changes by adding a
padding to a bunch of filesystem structures.

Based on a change made to the RHEL/CENTOS 8 kernel.

Leaf changes summary: 12 artifacts changed
Changed leaf types summary: 12 leaf types changed
Removed/Changed/Added functions summary: 0 Removed, 0 Changed, 0 Added function
Removed/Changed/Added variables summary: 0 Removed, 0 Changed, 0 Added variable

'struct address_space at fs.h:445:1' changed:
  type size changed from 1280 to 1536 (in bits)
  4 data member insertions:
    'u64 address_space::android_kabi_reserved1', at offset 1280 (in bits) at fs.h:472:1
    'u64 address_space::android_kabi_reserved2', at offset 1344 (in bits) at fs.h:473:1
    'u64 address_space::android_kabi_reserved3', at offset 1408 (in bits) at fs.h:474:1
    'u64 address_space::android_kabi_reserved4', at offset 1472 (in bits) at fs.h:475:1

'struct address_space_operations at fs.h:362:1' changed:
  type size changed from 1344 to 1600 (in bits)
  4 data member insertions:
    'u64 address_space_operations::android_kabi_reserved1', at offset 1344 (in bits) at fs.h:412:1
    'u64 address_space_operations::android_kabi_reserved2', at offset 1408 (in bits) at fs.h:413:1
    'u64 address_space_operations::android_kabi_reserved3', at offset 1472 (in bits) at fs.h:414:1
    'u64 address_space_operations::android_kabi_reserved4', at offset 1536 (in bits) at fs.h:415:1

'struct block_device at fs.h:473:1' changed:
  type size changed from 1728 to 1984 (in bits)
  4 data member insertions:
    'u64 block_device::android_kabi_reserved1', at offset 1728 (in bits) at fs.h:521:1
    'u64 block_device::android_kabi_reserved2', at offset 1792 (in bits) at fs.h:522:1
    'u64 block_device::android_kabi_reserved3', at offset 1856 (in bits) at fs.h:523:1
    'u64 block_device::android_kabi_reserved4', at offset 1920 (in bits) at fs.h:524:1

'struct file_lock at fs.h:1080:1' changed:
  type size changed from 1728 to 1984 (in bits)
  3 data member insertions:
    'list_head file_lock::android_reserved1', at offset 1728 (in bits) at fs.h:1142:1
    'u64 file_lock::android_kabi_reserved1', at offset 1856 (in bits) at fs.h:1143:1
    'u64 file_lock::android_kabi_reserved2', at offset 1920 (in bits) at fs.h:1144:1

'struct file_lock_operations at fs.h:1030:1' changed:
  type size changed from 128 to 256 (in bits)
  2 data member insertions:
    'u64 file_lock_operations::android_kabi_reserved1', at offset 128 (in bits) at fs.h:1053:1
    'u64 file_lock_operations::android_kabi_reserved2', at offset 192 (in bits) at fs.h:1054:1

'struct file_operations at fs.h:1843:1' changed:
  type size changed from 2048 to 2304 (in bits)
  4 data member insertions:
    'u64 file_operations::android_kabi_reserved1', at offset 2048 (in bits) at fs.h:1918:1
    'u64 file_operations::android_kabi_reserved2', at offset 2112 (in bits) at fs.h:1919:1
    'u64 file_operations::android_kabi_reserved3', at offset 2176 (in bits) at fs.h:1920:1
    'u64 file_operations::android_kabi_reserved4', at offset 2240 (in bits) at fs.h:1921:1

'struct file_system_type at fs.h:2245:1' changed:
  type size changed from 640 to 896 (in bits)
  4 data member insertions:
    'u64 file_system_type::android_kabi_reserved1', at offset 640 (in bits) at fs.h:2322:1
    'u64 file_system_type::android_kabi_reserved2', at offset 704 (in bits) at fs.h:2323:1
    'u64 file_system_type::android_kabi_reserved3', at offset 768 (in bits) at fs.h:2324:1
    'u64 file_system_type::android_kabi_reserved4', at offset 832 (in bits) at fs.h:2325:1

'struct inode at fs.h:628:1' changed:
  type size changed from 4800 to 5184 (in bits)
  2 data member insertions:
    'u64 inode::android_kabi_reserved1', at offset 5056 (in bits) at fs.h:756:1
    'u64 inode::android_kabi_reserved2', at offset 5120 (in bits) at fs.h:757:1

'struct inode_operations at fs.h:1885:1' changed:
  type size changed from 1536 to 2048 (in bits)
  4 data member insertions:
    'u64 inode_operations::android_kabi_reserved1', at offset 1472 (in bits) at fs.h:1955:1
    'u64 inode_operations::android_kabi_reserved2', at offset 1536 (in bits) at fs.h:1956:1
    'u64 inode_operations::android_kabi_reserved3', at offset 1600 (in bits) at fs.h:1957:1
    'u64 inode_operations::android_kabi_reserved4', at offset 1664 (in bits) at fs.h:1958:1

'struct lock_manager_operations at fs.h:1035:1' changed:
  type size changed from 448 to 576 (in bits)
  2 data member insertions:
    'u64 lock_manager_operations::android_kabi_reserved1', at offset 448 (in bits) at fs.h:1066:1
    'u64 lock_manager_operations::android_kabi_reserved2', at offset 512 (in bits) at fs.h:1067:1

'struct super_block at fs.h:1431:1' changed:
  type size changed from 11776 to 12288 (in bits)
  4 data member insertions:
    'u64 super_block::android_kabi_reserved1', at offset 11648 (in bits) at fs.h:1592:1
    'u64 super_block::android_kabi_reserved2', at offset 11712 (in bits) at fs.h:1593:1
    'u64 super_block::android_kabi_reserved3', at offset 11776 (in bits) at fs.h:1594:1
    'u64 super_block::android_kabi_reserved4', at offset 11840 (in bits) at fs.h:1595:1

'struct super_operations at fs.h:1966:1' changed:
  type size changed from 1920 to 2176 (in bits)
  4 data member insertions:
    'u64 super_operations::android_kabi_reserved1', at offset 1920 (in bits) at fs.h:2048:1
    'u64 super_operations::android_kabi_reserved2', at offset 1984 (in bits) at fs.h:2049:1
    'u64 super_operations::android_kabi_reserved3', at offset 2048 (in bits) at fs.h:2050:1
    'u64 super_operations::android_kabi_reserved4', at offset 2112 (in bits) at fs.h:2051:1

Bug: 151154716
Change-Id: Ida6d98d30f292c980ab07e0250fec5268c4c87ed
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

include/linux/fs.h

@@ -40,6 +40,7 @@
 #include <linux/fs_types.h>
 #include <linux/build_bug.h>
 #include <linux/stddef.h>
+#include <linux/android_kabi.h>
 
 #include <asm/byteorder.h>
 #include <uapi/linux/fs.h>
@@ -407,6 +408,11 @@ struct address_space_operations {
 	int (*swap_activate)(struct swap_info_struct *sis, struct file *file,
 				sector_t *span);
 	void (*swap_deactivate)(struct file *file);
+
+	ANDROID_KABI_RESERVE(1);
+	ANDROID_KABI_RESERVE(2);
+	ANDROID_KABI_RESERVE(3);
+	ANDROID_KABI_RESERVE(4);
 };
 
 extern const struct address_space_operations empty_aops;
@@ -462,6 +468,11 @@ struct address_space {
 	spinlock_t		private_lock;
 	struct list_head	private_list;
 	void			*private_data;
+
+	ANDROID_KABI_RESERVE(1);
+	ANDROID_KABI_RESERVE(2);
+	ANDROID_KABI_RESERVE(3);
+	ANDROID_KABI_RESERVE(4);
 } __attribute__((aligned(sizeof(long)))) __randomize_layout;
 	/*
 	 * On most architectures that alignment is already the case; but
@@ -506,6 +517,11 @@ struct block_device {
 	int			bd_fsfreeze_count;
 	/* Mutex for freeze */
 	struct mutex		bd_fsfreeze_mutex;
+
+	ANDROID_KABI_RESERVE(1);
+	ANDROID_KABI_RESERVE(2);
+	ANDROID_KABI_RESERVE(3);
+	ANDROID_KABI_RESERVE(4);
 } __randomize_layout;
 
 /* XArray tags, for tagging dirty and writeback pages in the pagecache. */
@@ -736,6 +752,9 @@ struct inode {
 #endif
 
 	void			*i_private; /* fs or device private pointer */
+
+	ANDROID_KABI_RESERVE(1);
+	ANDROID_KABI_RESERVE(2);
 } __randomize_layout;
 
 struct timespec64 timestamp_truncate(struct timespec64 t, struct inode *inode);
@@ -1030,6 +1049,9 @@ struct file_lock;
 struct file_lock_operations {
 	void (*fl_copy_lock)(struct file_lock *, struct file_lock *);
 	void (*fl_release_private)(struct file_lock *);
+
+	ANDROID_KABI_RESERVE(1);
+	ANDROID_KABI_RESERVE(2);
 };
 
 struct lock_manager_operations {
@@ -1040,6 +1062,9 @@ struct lock_manager_operations {
 	bool (*lm_break)(struct file_lock *);
 	int (*lm_change)(struct file_lock *, int, struct list_head *);
 	void (*lm_setup)(struct file_lock *, void **);
+
+	ANDROID_KABI_RESERVE(1);
+	ANDROID_KABI_RESERVE(2);
 };
 
 struct lock_manager {
@@ -1113,6 +1138,10 @@ struct file_lock {
 			unsigned int	debug_id;
 		} afs;
 	} fl_u;
+
+	struct list_head android_reserved1;	/* not a macro as we might just need it as-is */
+	ANDROID_KABI_RESERVE(1);
+	ANDROID_KABI_RESERVE(2);
 } __randomize_layout;
 
 struct file_lock_context {
@@ -1559,6 +1588,11 @@ struct super_block {
 
 	spinlock_t		s_inode_wblist_lock;
 	struct list_head	s_inodes_wb;	/* writeback inodes */
+
+	ANDROID_KABI_RESERVE(1);
+	ANDROID_KABI_RESERVE(2);
+	ANDROID_KABI_RESERVE(3);
+	ANDROID_KABI_RESERVE(4);
 } __randomize_layout;
 
 /* Helper functions so that in most cases filesystems will
@@ -1880,6 +1914,11 @@ struct file_operations {
 				   struct file *file_out, loff_t pos_out,
 				   loff_t len, unsigned int remap_flags);
 	int (*fadvise)(struct file *, loff_t, loff_t, int);
+
+	ANDROID_KABI_RESERVE(1);
+	ANDROID_KABI_RESERVE(2);
+	ANDROID_KABI_RESERVE(3);
+	ANDROID_KABI_RESERVE(4);
 } __randomize_layout;
 
 struct inode_operations {
@@ -1912,6 +1951,11 @@ struct inode_operations {
 			   umode_t create_mode);
 	int (*tmpfile) (struct inode *, struct dentry *, umode_t);
 	int (*set_acl)(struct inode *, struct posix_acl *, int);
+
+	ANDROID_KABI_RESERVE(1);
+	ANDROID_KABI_RESERVE(2);
+	ANDROID_KABI_RESERVE(3);
+	ANDROID_KABI_RESERVE(4);
 } ____cacheline_aligned;
 
 static inline ssize_t call_read_iter(struct file *file, struct kiocb *kio,
@@ -2000,6 +2044,11 @@ struct super_operations {
 				  struct shrink_control *);
 	long (*free_cached_objects)(struct super_block *,
 				    struct shrink_control *);
+
+	ANDROID_KABI_RESERVE(1);
+	ANDROID_KABI_RESERVE(2);
+	ANDROID_KABI_RESERVE(3);
+	ANDROID_KABI_RESERVE(4);
 };
 
 /*
@@ -2269,6 +2318,11 @@ struct file_system_type {
 	struct lock_class_key i_lock_key;
 	struct lock_class_key i_mutex_key;
 	struct lock_class_key i_mutex_dir_key;
+
+	ANDROID_KABI_RESERVE(1);
+	ANDROID_KABI_RESERVE(2);
+	ANDROID_KABI_RESERVE(3);
+	ANDROID_KABI_RESERVE(4);
 };
 
 #define MODULE_ALIAS_FS(NAME) MODULE_ALIAS("fs-" NAME)