xref: /openbmc/linux/fs/ext2/ext2.h (revision 97a532c3)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Copyright (C) 1992, 1993, 1994, 1995
4  * Remy Card (card@masi.ibp.fr)
5  * Laboratoire MASI - Institut Blaise Pascal
6  * Universite Pierre et Marie Curie (Paris VI)
7  *
8  *  from
9  *
10  *  linux/include/linux/minix_fs.h
11  *
12  *  Copyright (C) 1991, 1992  Linus Torvalds
13  */
14 #include <linux/fs.h>
15 #include <linux/ext2_fs.h>
16 #include <linux/blockgroup_lock.h>
17 #include <linux/percpu_counter.h>
18 #include <linux/rbtree.h>
19 #include <linux/mm.h>
20 #include <linux/highmem.h>
21 
22 /* XXX Here for now... not interested in restructing headers JUST now */
23 
24 /* data type for block offset of block group */
25 typedef int ext2_grpblk_t;
26 
27 /* data type for filesystem-wide blocks number */
28 typedef unsigned long ext2_fsblk_t;
29 
30 #define E2FSBLK "%lu"
31 
32 struct ext2_reserve_window {
33 	ext2_fsblk_t		_rsv_start;	/* First byte reserved */
34 	ext2_fsblk_t		_rsv_end;	/* Last byte reserved or 0 */
35 };
36 
37 struct ext2_reserve_window_node {
38 	struct rb_node	 	rsv_node;
39 	__u32			rsv_goal_size;
40 	__u32			rsv_alloc_hit;
41 	struct ext2_reserve_window	rsv_window;
42 };
43 
44 struct ext2_block_alloc_info {
45 	/* information about reservation window */
46 	struct ext2_reserve_window_node	rsv_window_node;
47 	/*
48 	 * was i_next_alloc_block in ext2_inode_info
49 	 * is the logical (file-relative) number of the
50 	 * most-recently-allocated block in this file.
51 	 * We use this for detecting linearly ascending allocation requests.
52 	 */
53 	__u32			last_alloc_logical_block;
54 	/*
55 	 * Was i_next_alloc_goal in ext2_inode_info
56 	 * is the *physical* companion to i_next_alloc_block.
57 	 * it is the physical block number of the block which was most-recently
58 	 * allocated to this file.  This gives us the goal (target) for the next
59 	 * allocation when we detect linearly ascending requests.
60 	 */
61 	ext2_fsblk_t		last_alloc_physical_block;
62 };
63 
64 #define rsv_start rsv_window._rsv_start
65 #define rsv_end rsv_window._rsv_end
66 
67 struct mb_cache;
68 
69 /*
70  * second extended-fs super-block data in memory
71  */
72 struct ext2_sb_info {
73 	unsigned long s_inodes_per_block;/* Number of inodes per block */
74 	unsigned long s_blocks_per_group;/* Number of blocks in a group */
75 	unsigned long s_inodes_per_group;/* Number of inodes in a group */
76 	unsigned long s_itb_per_group;	/* Number of inode table blocks per group */
77 	unsigned long s_gdb_count;	/* Number of group descriptor blocks */
78 	unsigned long s_desc_per_block;	/* Number of group descriptors per block */
79 	unsigned long s_groups_count;	/* Number of groups in the fs */
80 	unsigned long s_overhead_last;  /* Last calculated overhead */
81 	unsigned long s_blocks_last;    /* Last seen block count */
82 	struct buffer_head * s_sbh;	/* Buffer containing the super block */
83 	struct ext2_super_block * s_es;	/* Pointer to the super block in the buffer */
84 	struct buffer_head ** s_group_desc;
85 	unsigned long  s_mount_opt;
86 	unsigned long s_sb_block;
87 	kuid_t s_resuid;
88 	kgid_t s_resgid;
89 	unsigned short s_mount_state;
90 	unsigned short s_pad;
91 	int s_addr_per_block_bits;
92 	int s_desc_per_block_bits;
93 	int s_inode_size;
94 	int s_first_ino;
95 	spinlock_t s_next_gen_lock;
96 	u32 s_next_generation;
97 	unsigned long s_dir_count;
98 	u8 *s_debts;
99 	struct percpu_counter s_freeblocks_counter;
100 	struct percpu_counter s_freeinodes_counter;
101 	struct percpu_counter s_dirs_counter;
102 	struct blockgroup_lock *s_blockgroup_lock;
103 	/* root of the per fs reservation window tree */
104 	spinlock_t s_rsv_window_lock;
105 	struct rb_root s_rsv_window_root;
106 	struct ext2_reserve_window_node s_rsv_window_head;
107 	/*
108 	 * s_lock protects against concurrent modifications of s_mount_state,
109 	 * s_blocks_last, s_overhead_last and the content of superblock's
110 	 * buffer pointed to by sbi->s_es.
111 	 *
112 	 * Note: It is used in ext2_show_options() to provide a consistent view
113 	 * of the mount options.
114 	 */
115 	spinlock_t s_lock;
116 	struct mb_cache *s_ea_block_cache;
117 	struct dax_device *s_daxdev;
118 	u64 s_dax_part_off;
119 };
120 
121 static inline spinlock_t *
122 sb_bgl_lock(struct ext2_sb_info *sbi, unsigned int block_group)
123 {
124 	return bgl_lock_ptr(sbi->s_blockgroup_lock, block_group);
125 }
126 
127 /*
128  * Define EXT2FS_DEBUG to produce debug messages
129  */
130 #undef EXT2FS_DEBUG
131 
132 /*
133  * Define EXT2_RESERVATION to reserve data blocks for expanding files
134  */
135 #define EXT2_DEFAULT_RESERVE_BLOCKS     8
136 /*max window size: 1024(direct blocks) + 3([t,d]indirect blocks) */
137 #define EXT2_MAX_RESERVE_BLOCKS         1027
138 #define EXT2_RESERVE_WINDOW_NOT_ALLOCATED 0
139 /*
140  * The second extended file system version
141  */
142 #define EXT2FS_DATE		"95/08/09"
143 #define EXT2FS_VERSION		"0.5b"
144 
145 /*
146  * Debug code
147  */
148 #ifdef EXT2FS_DEBUG
149 #	define ext2_debug(f, a...)	{ \
150 					printk ("EXT2-fs DEBUG (%s, %d): %s:", \
151 						__FILE__, __LINE__, __func__); \
152 				  	printk (f, ## a); \
153 					}
154 #else
155 #	define ext2_debug(f, a...)	/**/
156 #endif
157 
158 /*
159  * Special inode numbers
160  */
161 #define	EXT2_BAD_INO		 1	/* Bad blocks inode */
162 #define EXT2_ROOT_INO		 2	/* Root inode */
163 #define EXT2_BOOT_LOADER_INO	 5	/* Boot loader inode */
164 #define EXT2_UNDEL_DIR_INO	 6	/* Undelete directory inode */
165 
166 /* First non-reserved inode for old ext2 filesystems */
167 #define EXT2_GOOD_OLD_FIRST_INO	11
168 
169 static inline struct ext2_sb_info *EXT2_SB(struct super_block *sb)
170 {
171 	return sb->s_fs_info;
172 }
173 
174 /*
175  * Macro-instructions used to manage several block sizes
176  */
177 #define EXT2_MIN_BLOCK_SIZE		1024
178 #define	EXT2_MAX_BLOCK_SIZE		65536
179 #define EXT2_MIN_BLOCK_LOG_SIZE		  10
180 #define EXT2_MAX_BLOCK_LOG_SIZE		  16
181 #define EXT2_BLOCK_SIZE(s)		((s)->s_blocksize)
182 #define	EXT2_ADDR_PER_BLOCK(s)		(EXT2_BLOCK_SIZE(s) / sizeof (__u32))
183 #define EXT2_BLOCK_SIZE_BITS(s)		((s)->s_blocksize_bits)
184 #define	EXT2_ADDR_PER_BLOCK_BITS(s)	(EXT2_SB(s)->s_addr_per_block_bits)
185 #define EXT2_INODE_SIZE(s)		(EXT2_SB(s)->s_inode_size)
186 #define EXT2_FIRST_INO(s)		(EXT2_SB(s)->s_first_ino)
187 
188 /*
189  * Structure of a blocks group descriptor
190  */
191 struct ext2_group_desc
192 {
193 	__le32	bg_block_bitmap;		/* Blocks bitmap block */
194 	__le32	bg_inode_bitmap;		/* Inodes bitmap block */
195 	__le32	bg_inode_table;		/* Inodes table block */
196 	__le16	bg_free_blocks_count;	/* Free blocks count */
197 	__le16	bg_free_inodes_count;	/* Free inodes count */
198 	__le16	bg_used_dirs_count;	/* Directories count */
199 	__le16	bg_pad;
200 	__le32	bg_reserved[3];
201 };
202 
203 /*
204  * Macro-instructions used to manage group descriptors
205  */
206 #define EXT2_BLOCKS_PER_GROUP(s)	(EXT2_SB(s)->s_blocks_per_group)
207 #define EXT2_DESC_PER_BLOCK(s)		(EXT2_SB(s)->s_desc_per_block)
208 #define EXT2_INODES_PER_GROUP(s)	(EXT2_SB(s)->s_inodes_per_group)
209 #define EXT2_DESC_PER_BLOCK_BITS(s)	(EXT2_SB(s)->s_desc_per_block_bits)
210 
211 /*
212  * Constants relative to the data blocks
213  */
214 #define	EXT2_NDIR_BLOCKS		12
215 #define	EXT2_IND_BLOCK			EXT2_NDIR_BLOCKS
216 #define	EXT2_DIND_BLOCK			(EXT2_IND_BLOCK + 1)
217 #define	EXT2_TIND_BLOCK			(EXT2_DIND_BLOCK + 1)
218 #define	EXT2_N_BLOCKS			(EXT2_TIND_BLOCK + 1)
219 
220 /*
221  * Inode flags (GETFLAGS/SETFLAGS)
222  */
223 #define	EXT2_SECRM_FL			FS_SECRM_FL	/* Secure deletion */
224 #define	EXT2_UNRM_FL			FS_UNRM_FL	/* Undelete */
225 #define	EXT2_COMPR_FL			FS_COMPR_FL	/* Compress file */
226 #define EXT2_SYNC_FL			FS_SYNC_FL	/* Synchronous updates */
227 #define EXT2_IMMUTABLE_FL		FS_IMMUTABLE_FL	/* Immutable file */
228 #define EXT2_APPEND_FL			FS_APPEND_FL	/* writes to file may only append */
229 #define EXT2_NODUMP_FL			FS_NODUMP_FL	/* do not dump file */
230 #define EXT2_NOATIME_FL			FS_NOATIME_FL	/* do not update atime */
231 /* Reserved for compression usage... */
232 #define EXT2_DIRTY_FL			FS_DIRTY_FL
233 #define EXT2_COMPRBLK_FL		FS_COMPRBLK_FL	/* One or more compressed clusters */
234 #define EXT2_NOCOMP_FL			FS_NOCOMP_FL	/* Don't compress */
235 #define EXT2_ECOMPR_FL			FS_ECOMPR_FL	/* Compression error */
236 /* End compression flags --- maybe not all used */
237 #define EXT2_BTREE_FL			FS_BTREE_FL	/* btree format dir */
238 #define EXT2_INDEX_FL			FS_INDEX_FL	/* hash-indexed directory */
239 #define EXT2_IMAGIC_FL			FS_IMAGIC_FL	/* AFS directory */
240 #define EXT2_JOURNAL_DATA_FL		FS_JOURNAL_DATA_FL /* Reserved for ext3 */
241 #define EXT2_NOTAIL_FL			FS_NOTAIL_FL	/* file tail should not be merged */
242 #define EXT2_DIRSYNC_FL			FS_DIRSYNC_FL	/* dirsync behaviour (directories only) */
243 #define EXT2_TOPDIR_FL			FS_TOPDIR_FL	/* Top of directory hierarchies*/
244 #define EXT2_RESERVED_FL		FS_RESERVED_FL	/* reserved for ext2 lib */
245 
246 #define EXT2_FL_USER_VISIBLE		FS_FL_USER_VISIBLE	/* User visible flags */
247 #define EXT2_FL_USER_MODIFIABLE		FS_FL_USER_MODIFIABLE	/* User modifiable flags */
248 
249 /* Flags that should be inherited by new inodes from their parent. */
250 #define EXT2_FL_INHERITED (EXT2_SECRM_FL | EXT2_UNRM_FL | EXT2_COMPR_FL |\
251 			   EXT2_SYNC_FL | EXT2_NODUMP_FL |\
252 			   EXT2_NOATIME_FL | EXT2_COMPRBLK_FL |\
253 			   EXT2_NOCOMP_FL | EXT2_JOURNAL_DATA_FL |\
254 			   EXT2_NOTAIL_FL | EXT2_DIRSYNC_FL)
255 
256 /* Flags that are appropriate for regular files (all but dir-specific ones). */
257 #define EXT2_REG_FLMASK (~(EXT2_DIRSYNC_FL | EXT2_TOPDIR_FL))
258 
259 /* Flags that are appropriate for non-directories/regular files. */
260 #define EXT2_OTHER_FLMASK (EXT2_NODUMP_FL | EXT2_NOATIME_FL)
261 
262 /* Mask out flags that are inappropriate for the given type of inode. */
263 static inline __u32 ext2_mask_flags(umode_t mode, __u32 flags)
264 {
265 	if (S_ISDIR(mode))
266 		return flags;
267 	else if (S_ISREG(mode))
268 		return flags & EXT2_REG_FLMASK;
269 	else
270 		return flags & EXT2_OTHER_FLMASK;
271 }
272 
273 /*
274  * ioctl commands
275  */
276 #define	EXT2_IOC_GETVERSION		FS_IOC_GETVERSION
277 #define	EXT2_IOC_SETVERSION		FS_IOC_SETVERSION
278 #define	EXT2_IOC_GETRSVSZ		_IOR('f', 5, long)
279 #define	EXT2_IOC_SETRSVSZ		_IOW('f', 6, long)
280 
281 /*
282  * ioctl commands in 32 bit emulation
283  */
284 #define EXT2_IOC32_GETVERSION		FS_IOC32_GETVERSION
285 #define EXT2_IOC32_SETVERSION		FS_IOC32_SETVERSION
286 
287 /*
288  * Structure of an inode on the disk
289  */
290 struct ext2_inode {
291 	__le16	i_mode;		/* File mode */
292 	__le16	i_uid;		/* Low 16 bits of Owner Uid */
293 	__le32	i_size;		/* Size in bytes */
294 	__le32	i_atime;	/* Access time */
295 	__le32	i_ctime;	/* Creation time */
296 	__le32	i_mtime;	/* Modification time */
297 	__le32	i_dtime;	/* Deletion Time */
298 	__le16	i_gid;		/* Low 16 bits of Group Id */
299 	__le16	i_links_count;	/* Links count */
300 	__le32	i_blocks;	/* Blocks count */
301 	__le32	i_flags;	/* File flags */
302 	union {
303 		struct {
304 			__le32  l_i_reserved1;
305 		} linux1;
306 		struct {
307 			__le32  h_i_translator;
308 		} hurd1;
309 		struct {
310 			__le32  m_i_reserved1;
311 		} masix1;
312 	} osd1;				/* OS dependent 1 */
313 	__le32	i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
314 	__le32	i_generation;	/* File version (for NFS) */
315 	__le32	i_file_acl;	/* File ACL */
316 	__le32	i_dir_acl;	/* Directory ACL */
317 	__le32	i_faddr;	/* Fragment address */
318 	union {
319 		struct {
320 			__u8	l_i_frag;	/* Fragment number */
321 			__u8	l_i_fsize;	/* Fragment size */
322 			__u16	i_pad1;
323 			__le16	l_i_uid_high;	/* these 2 fields    */
324 			__le16	l_i_gid_high;	/* were reserved2[0] */
325 			__u32	l_i_reserved2;
326 		} linux2;
327 		struct {
328 			__u8	h_i_frag;	/* Fragment number */
329 			__u8	h_i_fsize;	/* Fragment size */
330 			__le16	h_i_mode_high;
331 			__le16	h_i_uid_high;
332 			__le16	h_i_gid_high;
333 			__le32	h_i_author;
334 		} hurd2;
335 		struct {
336 			__u8	m_i_frag;	/* Fragment number */
337 			__u8	m_i_fsize;	/* Fragment size */
338 			__u16	m_pad1;
339 			__u32	m_i_reserved2[2];
340 		} masix2;
341 	} osd2;				/* OS dependent 2 */
342 };
343 
344 #define i_size_high	i_dir_acl
345 
346 #define i_reserved1	osd1.linux1.l_i_reserved1
347 #define i_frag		osd2.linux2.l_i_frag
348 #define i_fsize		osd2.linux2.l_i_fsize
349 #define i_uid_low	i_uid
350 #define i_gid_low	i_gid
351 #define i_uid_high	osd2.linux2.l_i_uid_high
352 #define i_gid_high	osd2.linux2.l_i_gid_high
353 #define i_reserved2	osd2.linux2.l_i_reserved2
354 
355 /*
356  * File system states
357  */
358 #define	EXT2_VALID_FS			0x0001	/* Unmounted cleanly */
359 #define	EXT2_ERROR_FS			0x0002	/* Errors detected */
360 #define	EFSCORRUPTED			EUCLEAN	/* Filesystem is corrupted */
361 
362 /*
363  * Mount flags
364  */
365 #define EXT2_MOUNT_OLDALLOC		0x000002  /* Don't use the new Orlov allocator */
366 #define EXT2_MOUNT_GRPID		0x000004  /* Create files with directory's group */
367 #define EXT2_MOUNT_DEBUG		0x000008  /* Some debugging messages */
368 #define EXT2_MOUNT_ERRORS_CONT		0x000010  /* Continue on errors */
369 #define EXT2_MOUNT_ERRORS_RO		0x000020  /* Remount fs ro on errors */
370 #define EXT2_MOUNT_ERRORS_PANIC		0x000040  /* Panic on errors */
371 #define EXT2_MOUNT_MINIX_DF		0x000080  /* Mimics the Minix statfs */
372 #define EXT2_MOUNT_NOBH			0x000100  /* No buffer_heads */
373 #define EXT2_MOUNT_NO_UID32		0x000200  /* Disable 32-bit UIDs */
374 #define EXT2_MOUNT_XATTR_USER		0x004000  /* Extended user attributes */
375 #define EXT2_MOUNT_POSIX_ACL		0x008000  /* POSIX Access Control Lists */
376 #define EXT2_MOUNT_XIP			0x010000  /* Obsolete, use DAX */
377 #define EXT2_MOUNT_USRQUOTA		0x020000  /* user quota */
378 #define EXT2_MOUNT_GRPQUOTA		0x040000  /* group quota */
379 #define EXT2_MOUNT_RESERVATION		0x080000  /* Preallocation */
380 #define EXT2_MOUNT_DAX			0x100000  /* Direct Access */
381 
382 
383 #define clear_opt(o, opt)		o &= ~EXT2_MOUNT_##opt
384 #define set_opt(o, opt)			o |= EXT2_MOUNT_##opt
385 #define test_opt(sb, opt)		(EXT2_SB(sb)->s_mount_opt & \
386 					 EXT2_MOUNT_##opt)
387 /*
388  * Maximal mount counts between two filesystem checks
389  */
390 #define EXT2_DFL_MAX_MNT_COUNT		20	/* Allow 20 mounts */
391 #define EXT2_DFL_CHECKINTERVAL		0	/* Don't use interval check */
392 
393 /*
394  * Behaviour when detecting errors
395  */
396 #define EXT2_ERRORS_CONTINUE		1	/* Continue execution */
397 #define EXT2_ERRORS_RO			2	/* Remount fs read-only */
398 #define EXT2_ERRORS_PANIC		3	/* Panic */
399 #define EXT2_ERRORS_DEFAULT		EXT2_ERRORS_CONTINUE
400 
401 /*
402  * Allocation flags
403  */
404 #define EXT2_ALLOC_NORESERVE            0x1	/* Do not use reservation
405 						 * window for allocation */
406 
407 /*
408  * Structure of the super block
409  */
410 struct ext2_super_block {
411 	__le32	s_inodes_count;		/* Inodes count */
412 	__le32	s_blocks_count;		/* Blocks count */
413 	__le32	s_r_blocks_count;	/* Reserved blocks count */
414 	__le32	s_free_blocks_count;	/* Free blocks count */
415 	__le32	s_free_inodes_count;	/* Free inodes count */
416 	__le32	s_first_data_block;	/* First Data Block */
417 	__le32	s_log_block_size;	/* Block size */
418 	__le32	s_log_frag_size;	/* Fragment size */
419 	__le32	s_blocks_per_group;	/* # Blocks per group */
420 	__le32	s_frags_per_group;	/* # Fragments per group */
421 	__le32	s_inodes_per_group;	/* # Inodes per group */
422 	__le32	s_mtime;		/* Mount time */
423 	__le32	s_wtime;		/* Write time */
424 	__le16	s_mnt_count;		/* Mount count */
425 	__le16	s_max_mnt_count;	/* Maximal mount count */
426 	__le16	s_magic;		/* Magic signature */
427 	__le16	s_state;		/* File system state */
428 	__le16	s_errors;		/* Behaviour when detecting errors */
429 	__le16	s_minor_rev_level; 	/* minor revision level */
430 	__le32	s_lastcheck;		/* time of last check */
431 	__le32	s_checkinterval;	/* max. time between checks */
432 	__le32	s_creator_os;		/* OS */
433 	__le32	s_rev_level;		/* Revision level */
434 	__le16	s_def_resuid;		/* Default uid for reserved blocks */
435 	__le16	s_def_resgid;		/* Default gid for reserved blocks */
436 	/*
437 	 * These fields are for EXT2_DYNAMIC_REV superblocks only.
438 	 *
439 	 * Note: the difference between the compatible feature set and
440 	 * the incompatible feature set is that if there is a bit set
441 	 * in the incompatible feature set that the kernel doesn't
442 	 * know about, it should refuse to mount the filesystem.
443 	 *
444 	 * e2fsck's requirements are more strict; if it doesn't know
445 	 * about a feature in either the compatible or incompatible
446 	 * feature set, it must abort and not try to meddle with
447 	 * things it doesn't understand...
448 	 */
449 	__le32	s_first_ino; 		/* First non-reserved inode */
450 	__le16   s_inode_size; 		/* size of inode structure */
451 	__le16	s_block_group_nr; 	/* block group # of this superblock */
452 	__le32	s_feature_compat; 	/* compatible feature set */
453 	__le32	s_feature_incompat; 	/* incompatible feature set */
454 	__le32	s_feature_ro_compat; 	/* readonly-compatible feature set */
455 	__u8	s_uuid[16];		/* 128-bit uuid for volume */
456 	char	s_volume_name[16]; 	/* volume name */
457 	char	s_last_mounted[64]; 	/* directory where last mounted */
458 	__le32	s_algorithm_usage_bitmap; /* For compression */
459 	/*
460 	 * Performance hints.  Directory preallocation should only
461 	 * happen if the EXT2_COMPAT_PREALLOC flag is on.
462 	 */
463 	__u8	s_prealloc_blocks;	/* Nr of blocks to try to preallocate*/
464 	__u8	s_prealloc_dir_blocks;	/* Nr to preallocate for dirs */
465 	__u16	s_padding1;
466 	/*
467 	 * Journaling support valid if EXT3_FEATURE_COMPAT_HAS_JOURNAL set.
468 	 */
469 	__u8	s_journal_uuid[16];	/* uuid of journal superblock */
470 	__u32	s_journal_inum;		/* inode number of journal file */
471 	__u32	s_journal_dev;		/* device number of journal file */
472 	__u32	s_last_orphan;		/* start of list of inodes to delete */
473 	__u32	s_hash_seed[4];		/* HTREE hash seed */
474 	__u8	s_def_hash_version;	/* Default hash version to use */
475 	__u8	s_reserved_char_pad;
476 	__u16	s_reserved_word_pad;
477 	__le32	s_default_mount_opts;
478  	__le32	s_first_meta_bg; 	/* First metablock block group */
479 	__u32	s_reserved[190];	/* Padding to the end of the block */
480 };
481 
482 /*
483  * Codes for operating systems
484  */
485 #define EXT2_OS_LINUX		0
486 #define EXT2_OS_HURD		1
487 #define EXT2_OS_MASIX		2
488 #define EXT2_OS_FREEBSD		3
489 #define EXT2_OS_LITES		4
490 
491 /*
492  * Revision levels
493  */
494 #define EXT2_GOOD_OLD_REV	0	/* The good old (original) format */
495 #define EXT2_DYNAMIC_REV	1 	/* V2 format w/ dynamic inode sizes */
496 
497 #define EXT2_CURRENT_REV	EXT2_GOOD_OLD_REV
498 #define EXT2_MAX_SUPP_REV	EXT2_DYNAMIC_REV
499 
500 #define EXT2_GOOD_OLD_INODE_SIZE 128
501 
502 /*
503  * Feature set definitions
504  */
505 
506 #define EXT2_HAS_COMPAT_FEATURE(sb,mask)			\
507 	( EXT2_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask) )
508 #define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask)			\
509 	( EXT2_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask) )
510 #define EXT2_HAS_INCOMPAT_FEATURE(sb,mask)			\
511 	( EXT2_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask) )
512 #define EXT2_SET_COMPAT_FEATURE(sb,mask)			\
513 	EXT2_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
514 #define EXT2_SET_RO_COMPAT_FEATURE(sb,mask)			\
515 	EXT2_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
516 #define EXT2_SET_INCOMPAT_FEATURE(sb,mask)			\
517 	EXT2_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
518 #define EXT2_CLEAR_COMPAT_FEATURE(sb,mask)			\
519 	EXT2_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
520 #define EXT2_CLEAR_RO_COMPAT_FEATURE(sb,mask)			\
521 	EXT2_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
522 #define EXT2_CLEAR_INCOMPAT_FEATURE(sb,mask)			\
523 	EXT2_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
524 
525 #define EXT2_FEATURE_COMPAT_DIR_PREALLOC	0x0001
526 #define EXT2_FEATURE_COMPAT_IMAGIC_INODES	0x0002
527 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL		0x0004
528 #define EXT2_FEATURE_COMPAT_EXT_ATTR		0x0008
529 #define EXT2_FEATURE_COMPAT_RESIZE_INO		0x0010
530 #define EXT2_FEATURE_COMPAT_DIR_INDEX		0x0020
531 #define EXT2_FEATURE_COMPAT_ANY			0xffffffff
532 
533 #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
534 #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
535 #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR	0x0004
536 #define EXT2_FEATURE_RO_COMPAT_ANY		0xffffffff
537 
538 #define EXT2_FEATURE_INCOMPAT_COMPRESSION	0x0001
539 #define EXT2_FEATURE_INCOMPAT_FILETYPE		0x0002
540 #define EXT3_FEATURE_INCOMPAT_RECOVER		0x0004
541 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008
542 #define EXT2_FEATURE_INCOMPAT_META_BG		0x0010
543 #define EXT2_FEATURE_INCOMPAT_ANY		0xffffffff
544 
545 #define EXT2_FEATURE_COMPAT_SUPP	EXT2_FEATURE_COMPAT_EXT_ATTR
546 #define EXT2_FEATURE_INCOMPAT_SUPP	(EXT2_FEATURE_INCOMPAT_FILETYPE| \
547 					 EXT2_FEATURE_INCOMPAT_META_BG)
548 #define EXT2_FEATURE_RO_COMPAT_SUPP	(EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
549 					 EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
550 					 EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
551 #define EXT2_FEATURE_RO_COMPAT_UNSUPPORTED	~EXT2_FEATURE_RO_COMPAT_SUPP
552 #define EXT2_FEATURE_INCOMPAT_UNSUPPORTED	~EXT2_FEATURE_INCOMPAT_SUPP
553 
554 /*
555  * Default values for user and/or group using reserved blocks
556  */
557 #define	EXT2_DEF_RESUID		0
558 #define	EXT2_DEF_RESGID		0
559 
560 /*
561  * Default mount options
562  */
563 #define EXT2_DEFM_DEBUG		0x0001
564 #define EXT2_DEFM_BSDGROUPS	0x0002
565 #define EXT2_DEFM_XATTR_USER	0x0004
566 #define EXT2_DEFM_ACL		0x0008
567 #define EXT2_DEFM_UID16		0x0010
568     /* Not used by ext2, but reserved for use by ext3 */
569 #define EXT3_DEFM_JMODE		0x0060
570 #define EXT3_DEFM_JMODE_DATA	0x0020
571 #define EXT3_DEFM_JMODE_ORDERED	0x0040
572 #define EXT3_DEFM_JMODE_WBACK	0x0060
573 
574 /*
575  * Structure of a directory entry
576  */
577 
578 struct ext2_dir_entry {
579 	__le32	inode;			/* Inode number */
580 	__le16	rec_len;		/* Directory entry length */
581 	__le16	name_len;		/* Name length */
582 	char	name[];			/* File name, up to EXT2_NAME_LEN */
583 };
584 
585 /*
586  * The new version of the directory entry.  Since EXT2 structures are
587  * stored in intel byte order, and the name_len field could never be
588  * bigger than 255 chars, it's safe to reclaim the extra byte for the
589  * file_type field.
590  */
591 struct ext2_dir_entry_2 {
592 	__le32	inode;			/* Inode number */
593 	__le16	rec_len;		/* Directory entry length */
594 	__u8	name_len;		/* Name length */
595 	__u8	file_type;
596 	char	name[];			/* File name, up to EXT2_NAME_LEN */
597 };
598 
599 /*
600  * EXT2_DIR_PAD defines the directory entries boundaries
601  *
602  * NOTE: It must be a multiple of 4
603  */
604 #define EXT2_DIR_PAD		 	4
605 #define EXT2_DIR_ROUND 			(EXT2_DIR_PAD - 1)
606 #define EXT2_DIR_REC_LEN(name_len)	(((name_len) + 8 + EXT2_DIR_ROUND) & \
607 					 ~EXT2_DIR_ROUND)
608 #define EXT2_MAX_REC_LEN		((1<<16)-1)
609 
610 static inline void verify_offsets(void)
611 {
612 #define A(x,y) BUILD_BUG_ON(x != offsetof(struct ext2_super_block, y));
613 	A(EXT2_SB_MAGIC_OFFSET, s_magic);
614 	A(EXT2_SB_BLOCKS_OFFSET, s_blocks_count);
615 	A(EXT2_SB_BSIZE_OFFSET, s_log_block_size);
616 #undef A
617 }
618 
619 /*
620  * ext2 mount options
621  */
622 struct ext2_mount_options {
623 	unsigned long s_mount_opt;
624 	kuid_t s_resuid;
625 	kgid_t s_resgid;
626 };
627 
628 /*
629  * second extended file system inode data in memory
630  */
631 struct ext2_inode_info {
632 	__le32	i_data[15];
633 	__u32	i_flags;
634 	__u32	i_faddr;
635 	__u8	i_frag_no;
636 	__u8	i_frag_size;
637 	__u16	i_state;
638 	__u32	i_file_acl;
639 	__u32	i_dir_acl;
640 	__u32	i_dtime;
641 
642 	/*
643 	 * i_block_group is the number of the block group which contains
644 	 * this file's inode.  Constant across the lifetime of the inode,
645 	 * it is used for making block allocation decisions - we try to
646 	 * place a file's data blocks near its inode block, and new inodes
647 	 * near to their parent directory's inode.
648 	 */
649 	__u32	i_block_group;
650 
651 	/* block reservation info */
652 	struct ext2_block_alloc_info *i_block_alloc_info;
653 
654 	__u32	i_dir_start_lookup;
655 #ifdef CONFIG_EXT2_FS_XATTR
656 	/*
657 	 * Extended attributes can be read independently of the main file
658 	 * data. Taking i_mutex even when reading would cause contention
659 	 * between readers of EAs and writers of regular file data, so
660 	 * instead we synchronize on xattr_sem when reading or changing
661 	 * EAs.
662 	 */
663 	struct rw_semaphore xattr_sem;
664 #endif
665 	rwlock_t i_meta_lock;
666 
667 	/*
668 	 * truncate_mutex is for serialising ext2_truncate() against
669 	 * ext2_getblock().  It also protects the internals of the inode's
670 	 * reservation data structures: ext2_reserve_window and
671 	 * ext2_reserve_window_node.
672 	 */
673 	struct mutex truncate_mutex;
674 	struct inode	vfs_inode;
675 	struct list_head i_orphan;	/* unlinked but open inodes */
676 #ifdef CONFIG_QUOTA
677 	struct dquot __rcu *i_dquot[MAXQUOTAS];
678 #endif
679 };
680 
681 /*
682  * Inode dynamic state flags
683  */
684 #define EXT2_STATE_NEW			0x00000001 /* inode is newly created */
685 
686 
687 /*
688  * Function prototypes
689  */
690 
691 /*
692  * Ok, these declarations are also in <linux/kernel.h> but none of the
693  * ext2 source programs needs to include it so they are duplicated here.
694  */
695 
696 static inline struct ext2_inode_info *EXT2_I(struct inode *inode)
697 {
698 	return container_of(inode, struct ext2_inode_info, vfs_inode);
699 }
700 
701 /* balloc.c */
702 extern int ext2_bg_has_super(struct super_block *sb, int group);
703 extern unsigned long ext2_bg_num_gdb(struct super_block *sb, int group);
704 extern ext2_fsblk_t ext2_new_blocks(struct inode *, ext2_fsblk_t,
705 				unsigned long *, int *, unsigned int);
706 extern int ext2_data_block_valid(struct ext2_sb_info *sbi, ext2_fsblk_t start_blk,
707 				 unsigned int count);
708 extern void ext2_free_blocks(struct inode *, ext2_fsblk_t, unsigned long);
709 extern unsigned long ext2_count_free_blocks (struct super_block *);
710 extern unsigned long ext2_count_dirs (struct super_block *);
711 extern struct ext2_group_desc * ext2_get_group_desc(struct super_block * sb,
712 						    unsigned int block_group,
713 						    struct buffer_head ** bh);
714 extern void ext2_discard_reservation (struct inode *);
715 extern int ext2_should_retry_alloc(struct super_block *sb, int *retries);
716 extern void ext2_init_block_alloc_info(struct inode *);
717 extern void ext2_rsv_window_add(struct super_block *sb, struct ext2_reserve_window_node *rsv);
718 
719 /* dir.c */
720 extern int ext2_add_link (struct dentry *, struct inode *);
721 extern int ext2_inode_by_name(struct inode *dir,
722 			      const struct qstr *child, ino_t *ino);
723 extern int ext2_make_empty(struct inode *, struct inode *);
724 extern struct ext2_dir_entry_2 *ext2_find_entry(struct inode *, const struct qstr *,
725 						struct page **);
726 extern int ext2_delete_entry(struct ext2_dir_entry_2 *dir, struct page *page);
727 extern int ext2_empty_dir (struct inode *);
728 extern struct ext2_dir_entry_2 *ext2_dotdot(struct inode *dir, struct page **p);
729 int ext2_set_link(struct inode *dir, struct ext2_dir_entry_2 *de,
730 		struct page *page, struct inode *inode, bool update_times);
731 static inline void ext2_put_page(struct page *page, void *page_addr)
732 {
733 	kunmap_local(page_addr);
734 	put_page(page);
735 }
736 
737 /* ialloc.c */
738 extern struct inode * ext2_new_inode (struct inode *, umode_t, const struct qstr *);
739 extern void ext2_free_inode (struct inode *);
740 extern unsigned long ext2_count_free_inodes (struct super_block *);
741 extern unsigned long ext2_count_free (struct buffer_head *, unsigned);
742 
743 /* inode.c */
744 extern struct inode *ext2_iget (struct super_block *, unsigned long);
745 extern int ext2_write_inode (struct inode *, struct writeback_control *);
746 extern void ext2_evict_inode(struct inode *);
747 void ext2_write_failed(struct address_space *mapping, loff_t to);
748 extern int ext2_get_block(struct inode *, sector_t, struct buffer_head *, int);
749 extern int ext2_setattr (struct mnt_idmap *, struct dentry *, struct iattr *);
750 extern int ext2_getattr (struct mnt_idmap *, const struct path *,
751 			 struct kstat *, u32, unsigned int);
752 extern void ext2_set_inode_flags(struct inode *inode);
753 extern int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
754 		       u64 start, u64 len);
755 
756 /* ioctl.c */
757 extern int ext2_fileattr_get(struct dentry *dentry, struct fileattr *fa);
758 extern int ext2_fileattr_set(struct mnt_idmap *idmap,
759 			     struct dentry *dentry, struct fileattr *fa);
760 extern long ext2_ioctl(struct file *, unsigned int, unsigned long);
761 extern long ext2_compat_ioctl(struct file *, unsigned int, unsigned long);
762 
763 /* namei.c */
764 struct dentry *ext2_get_parent(struct dentry *child);
765 
766 /* super.c */
767 extern __printf(3, 4)
768 void ext2_error(struct super_block *, const char *, const char *, ...);
769 extern __printf(3, 4)
770 void ext2_msg(struct super_block *, const char *, const char *, ...);
771 extern void ext2_update_dynamic_rev (struct super_block *sb);
772 extern void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
773 			    int wait);
774 
775 /*
776  * Inodes and files operations
777  */
778 
779 /* dir.c */
780 extern const struct file_operations ext2_dir_operations;
781 
782 /* file.c */
783 extern int ext2_fsync(struct file *file, loff_t start, loff_t end,
784 		      int datasync);
785 extern const struct inode_operations ext2_file_inode_operations;
786 extern const struct file_operations ext2_file_operations;
787 
788 /* inode.c */
789 extern void ext2_set_file_ops(struct inode *inode);
790 extern const struct address_space_operations ext2_aops;
791 extern const struct iomap_ops ext2_iomap_ops;
792 
793 /* namei.c */
794 extern const struct inode_operations ext2_dir_inode_operations;
795 extern const struct inode_operations ext2_special_inode_operations;
796 
797 /* symlink.c */
798 extern const struct inode_operations ext2_fast_symlink_inode_operations;
799 extern const struct inode_operations ext2_symlink_inode_operations;
800 
801 static inline ext2_fsblk_t
802 ext2_group_first_block_no(struct super_block *sb, unsigned long group_no)
803 {
804 	return group_no * (ext2_fsblk_t)EXT2_BLOCKS_PER_GROUP(sb) +
805 		le32_to_cpu(EXT2_SB(sb)->s_es->s_first_data_block);
806 }
807 
808 static inline ext2_fsblk_t
809 ext2_group_last_block_no(struct super_block *sb, unsigned long group_no)
810 {
811 	struct ext2_sb_info *sbi = EXT2_SB(sb);
812 
813 	if (group_no == sbi->s_groups_count - 1)
814 		return le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
815 	else
816 		return ext2_group_first_block_no(sb, group_no) +
817 			EXT2_BLOCKS_PER_GROUP(sb) - 1;
818 }
819 
820 #define ext2_set_bit	__test_and_set_bit_le
821 #define ext2_clear_bit	__test_and_clear_bit_le
822 #define ext2_test_bit	test_bit_le
823 #define ext2_find_first_zero_bit	find_first_zero_bit_le
824 #define ext2_find_next_zero_bit		find_next_zero_bit_le
825