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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 
20 /* XXX Here for now... not interested in restructing headers JUST now */
21 
22 /* data type for block offset of block group */
23 typedef int ext2_grpblk_t;
24 
25 /* data type for filesystem-wide blocks number */
26 typedef unsigned long ext2_fsblk_t;
27 
28 #define E2FSBLK "%lu"
29 
30 struct ext2_reserve_window {
31 	ext2_fsblk_t		_rsv_start;	/* First byte reserved */
32 	ext2_fsblk_t		_rsv_end;	/* Last byte reserved or 0 */
33 };
34 
35 struct ext2_reserve_window_node {
36 	struct rb_node	 	rsv_node;
37 	__u32			rsv_goal_size;
38 	__u32			rsv_alloc_hit;
39 	struct ext2_reserve_window	rsv_window;
40 };
41 
42 struct ext2_block_alloc_info {
43 	/* information about reservation window */
44 	struct ext2_reserve_window_node	rsv_window_node;
45 	/*
46 	 * was i_next_alloc_block in ext2_inode_info
47 	 * is the logical (file-relative) number of the
48 	 * most-recently-allocated block in this file.
49 	 * We use this for detecting linearly ascending allocation requests.
50 	 */
51 	__u32			last_alloc_logical_block;
52 	/*
53 	 * Was i_next_alloc_goal in ext2_inode_info
54 	 * is the *physical* companion to i_next_alloc_block.
55 	 * it is the physical block number of the block which was most-recently
56 	 * allocated to this file.  This gives us the goal (target) for the next
57 	 * allocation when we detect linearly ascending requests.
58 	 */
59 	ext2_fsblk_t		last_alloc_physical_block;
60 };
61 
62 #define rsv_start rsv_window._rsv_start
63 #define rsv_end rsv_window._rsv_end
64 
65 struct mb_cache;
66 
67 /*
68  * second extended-fs super-block data in memory
69  */
70 struct ext2_sb_info {
71 	unsigned long s_inodes_per_block;/* Number of inodes per block */
72 	unsigned long s_blocks_per_group;/* Number of blocks in a group */
73 	unsigned long s_inodes_per_group;/* Number of inodes in a group */
74 	unsigned long s_itb_per_group;	/* Number of inode table blocks per group */
75 	unsigned long s_gdb_count;	/* Number of group descriptor blocks */
76 	unsigned long s_desc_per_block;	/* Number of group descriptors per block */
77 	unsigned long s_groups_count;	/* Number of groups in the fs */
78 	unsigned long s_overhead_last;  /* Last calculated overhead */
79 	unsigned long s_blocks_last;    /* Last seen block count */
80 	struct buffer_head * s_sbh;	/* Buffer containing the super block */
81 	struct ext2_super_block * s_es;	/* Pointer to the super block in the buffer */
82 	struct buffer_head ** s_group_desc;
83 	unsigned long  s_mount_opt;
84 	unsigned long s_sb_block;
85 	kuid_t s_resuid;
86 	kgid_t s_resgid;
87 	unsigned short s_mount_state;
88 	unsigned short s_pad;
89 	int s_addr_per_block_bits;
90 	int s_desc_per_block_bits;
91 	int s_inode_size;
92 	int s_first_ino;
93 	spinlock_t s_next_gen_lock;
94 	u32 s_next_generation;
95 	unsigned long s_dir_count;
96 	u8 *s_debts;
97 	struct percpu_counter s_freeblocks_counter;
98 	struct percpu_counter s_freeinodes_counter;
99 	struct percpu_counter s_dirs_counter;
100 	struct blockgroup_lock *s_blockgroup_lock;
101 	/* root of the per fs reservation window tree */
102 	spinlock_t s_rsv_window_lock;
103 	struct rb_root s_rsv_window_root;
104 	struct ext2_reserve_window_node s_rsv_window_head;
105 	/*
106 	 * s_lock protects against concurrent modifications of s_mount_state,
107 	 * s_blocks_last, s_overhead_last and the content of superblock's
108 	 * buffer pointed to by sbi->s_es.
109 	 *
110 	 * Note: It is used in ext2_show_options() to provide a consistent view
111 	 * of the mount options.
112 	 */
113 	spinlock_t s_lock;
114 	struct mb_cache *s_ea_block_cache;
115 	struct dax_device *s_daxdev;
116 };
117 
118 static inline spinlock_t *
sb_bgl_lock(struct ext2_sb_info * sbi,unsigned int block_group)119 sb_bgl_lock(struct ext2_sb_info *sbi, unsigned int block_group)
120 {
121 	return bgl_lock_ptr(sbi->s_blockgroup_lock, block_group);
122 }
123 
124 /*
125  * Define EXT2FS_DEBUG to produce debug messages
126  */
127 #undef EXT2FS_DEBUG
128 
129 /*
130  * Define EXT2_RESERVATION to reserve data blocks for expanding files
131  */
132 #define EXT2_DEFAULT_RESERVE_BLOCKS     8
133 /*max window size: 1024(direct blocks) + 3([t,d]indirect blocks) */
134 #define EXT2_MAX_RESERVE_BLOCKS         1027
135 #define EXT2_RESERVE_WINDOW_NOT_ALLOCATED 0
136 /*
137  * The second extended file system version
138  */
139 #define EXT2FS_DATE		"95/08/09"
140 #define EXT2FS_VERSION		"0.5b"
141 
142 /*
143  * Debug code
144  */
145 #ifdef EXT2FS_DEBUG
146 #	define ext2_debug(f, a...)	{ \
147 					printk ("EXT2-fs DEBUG (%s, %d): %s:", \
148 						__FILE__, __LINE__, __func__); \
149 				  	printk (f, ## a); \
150 					}
151 #else
152 #	define ext2_debug(f, a...)	/**/
153 #endif
154 
155 /*
156  * Special inode numbers
157  */
158 #define	EXT2_BAD_INO		 1	/* Bad blocks inode */
159 #define EXT2_ROOT_INO		 2	/* Root inode */
160 #define EXT2_BOOT_LOADER_INO	 5	/* Boot loader inode */
161 #define EXT2_UNDEL_DIR_INO	 6	/* Undelete directory inode */
162 
163 /* First non-reserved inode for old ext2 filesystems */
164 #define EXT2_GOOD_OLD_FIRST_INO	11
165 
EXT2_SB(struct super_block * sb)166 static inline struct ext2_sb_info *EXT2_SB(struct super_block *sb)
167 {
168 	return sb->s_fs_info;
169 }
170 
171 /*
172  * Macro-instructions used to manage several block sizes
173  */
174 #define EXT2_MIN_BLOCK_SIZE		1024
175 #define	EXT2_MAX_BLOCK_SIZE		4096
176 #define EXT2_MIN_BLOCK_LOG_SIZE		  10
177 #define EXT2_MAX_BLOCK_LOG_SIZE		  16
178 #define EXT2_BLOCK_SIZE(s)		((s)->s_blocksize)
179 #define	EXT2_ADDR_PER_BLOCK(s)		(EXT2_BLOCK_SIZE(s) / sizeof (__u32))
180 #define EXT2_BLOCK_SIZE_BITS(s)		((s)->s_blocksize_bits)
181 #define	EXT2_ADDR_PER_BLOCK_BITS(s)	(EXT2_SB(s)->s_addr_per_block_bits)
182 #define EXT2_INODE_SIZE(s)		(EXT2_SB(s)->s_inode_size)
183 #define EXT2_FIRST_INO(s)		(EXT2_SB(s)->s_first_ino)
184 
185 /*
186  * Structure of a blocks group descriptor
187  */
188 struct ext2_group_desc
189 {
190 	__le32	bg_block_bitmap;		/* Blocks bitmap block */
191 	__le32	bg_inode_bitmap;		/* Inodes bitmap block */
192 	__le32	bg_inode_table;		/* Inodes table block */
193 	__le16	bg_free_blocks_count;	/* Free blocks count */
194 	__le16	bg_free_inodes_count;	/* Free inodes count */
195 	__le16	bg_used_dirs_count;	/* Directories count */
196 	__le16	bg_pad;
197 	__le32	bg_reserved[3];
198 };
199 
200 /*
201  * Macro-instructions used to manage group descriptors
202  */
203 #define EXT2_BLOCKS_PER_GROUP(s)	(EXT2_SB(s)->s_blocks_per_group)
204 #define EXT2_DESC_PER_BLOCK(s)		(EXT2_SB(s)->s_desc_per_block)
205 #define EXT2_INODES_PER_GROUP(s)	(EXT2_SB(s)->s_inodes_per_group)
206 #define EXT2_DESC_PER_BLOCK_BITS(s)	(EXT2_SB(s)->s_desc_per_block_bits)
207 
208 /*
209  * Constants relative to the data blocks
210  */
211 #define	EXT2_NDIR_BLOCKS		12
212 #define	EXT2_IND_BLOCK			EXT2_NDIR_BLOCKS
213 #define	EXT2_DIND_BLOCK			(EXT2_IND_BLOCK + 1)
214 #define	EXT2_TIND_BLOCK			(EXT2_DIND_BLOCK + 1)
215 #define	EXT2_N_BLOCKS			(EXT2_TIND_BLOCK + 1)
216 
217 /*
218  * Inode flags (GETFLAGS/SETFLAGS)
219  */
220 #define	EXT2_SECRM_FL			FS_SECRM_FL	/* Secure deletion */
221 #define	EXT2_UNRM_FL			FS_UNRM_FL	/* Undelete */
222 #define	EXT2_COMPR_FL			FS_COMPR_FL	/* Compress file */
223 #define EXT2_SYNC_FL			FS_SYNC_FL	/* Synchronous updates */
224 #define EXT2_IMMUTABLE_FL		FS_IMMUTABLE_FL	/* Immutable file */
225 #define EXT2_APPEND_FL			FS_APPEND_FL	/* writes to file may only append */
226 #define EXT2_NODUMP_FL			FS_NODUMP_FL	/* do not dump file */
227 #define EXT2_NOATIME_FL			FS_NOATIME_FL	/* do not update atime */
228 /* Reserved for compression usage... */
229 #define EXT2_DIRTY_FL			FS_DIRTY_FL
230 #define EXT2_COMPRBLK_FL		FS_COMPRBLK_FL	/* One or more compressed clusters */
231 #define EXT2_NOCOMP_FL			FS_NOCOMP_FL	/* Don't compress */
232 #define EXT2_ECOMPR_FL			FS_ECOMPR_FL	/* Compression error */
233 /* End compression flags --- maybe not all used */
234 #define EXT2_BTREE_FL			FS_BTREE_FL	/* btree format dir */
235 #define EXT2_INDEX_FL			FS_INDEX_FL	/* hash-indexed directory */
236 #define EXT2_IMAGIC_FL			FS_IMAGIC_FL	/* AFS directory */
237 #define EXT2_JOURNAL_DATA_FL		FS_JOURNAL_DATA_FL /* Reserved for ext3 */
238 #define EXT2_NOTAIL_FL			FS_NOTAIL_FL	/* file tail should not be merged */
239 #define EXT2_DIRSYNC_FL			FS_DIRSYNC_FL	/* dirsync behaviour (directories only) */
240 #define EXT2_TOPDIR_FL			FS_TOPDIR_FL	/* Top of directory hierarchies*/
241 #define EXT2_RESERVED_FL		FS_RESERVED_FL	/* reserved for ext2 lib */
242 
243 #define EXT2_FL_USER_VISIBLE		FS_FL_USER_VISIBLE	/* User visible flags */
244 #define EXT2_FL_USER_MODIFIABLE		FS_FL_USER_MODIFIABLE	/* User modifiable flags */
245 
246 /* Flags that should be inherited by new inodes from their parent. */
247 #define EXT2_FL_INHERITED (EXT2_SECRM_FL | EXT2_UNRM_FL | EXT2_COMPR_FL |\
248 			   EXT2_SYNC_FL | EXT2_NODUMP_FL |\
249 			   EXT2_NOATIME_FL | EXT2_COMPRBLK_FL |\
250 			   EXT2_NOCOMP_FL | EXT2_JOURNAL_DATA_FL |\
251 			   EXT2_NOTAIL_FL | EXT2_DIRSYNC_FL)
252 
253 /* Flags that are appropriate for regular files (all but dir-specific ones). */
254 #define EXT2_REG_FLMASK (~(EXT2_DIRSYNC_FL | EXT2_TOPDIR_FL))
255 
256 /* Flags that are appropriate for non-directories/regular files. */
257 #define EXT2_OTHER_FLMASK (EXT2_NODUMP_FL | EXT2_NOATIME_FL)
258 
259 /* Mask out flags that are inappropriate for the given type of inode. */
ext2_mask_flags(umode_t mode,__u32 flags)260 static inline __u32 ext2_mask_flags(umode_t mode, __u32 flags)
261 {
262 	if (S_ISDIR(mode))
263 		return flags;
264 	else if (S_ISREG(mode))
265 		return flags & EXT2_REG_FLMASK;
266 	else
267 		return flags & EXT2_OTHER_FLMASK;
268 }
269 
270 /*
271  * ioctl commands
272  */
273 #define	EXT2_IOC_GETFLAGS		FS_IOC_GETFLAGS
274 #define	EXT2_IOC_SETFLAGS		FS_IOC_SETFLAGS
275 #define	EXT2_IOC_GETVERSION		FS_IOC_GETVERSION
276 #define	EXT2_IOC_SETVERSION		FS_IOC_SETVERSION
277 #define	EXT2_IOC_GETRSVSZ		_IOR('f', 5, long)
278 #define	EXT2_IOC_SETRSVSZ		_IOW('f', 6, long)
279 
280 /*
281  * ioctl commands in 32 bit emulation
282  */
283 #define EXT2_IOC32_GETFLAGS		FS_IOC32_GETFLAGS
284 #define EXT2_IOC32_SETFLAGS		FS_IOC32_SETFLAGS
285 #define EXT2_IOC32_GETVERSION		FS_IOC32_GETVERSION
286 #define EXT2_IOC32_SETVERSION		FS_IOC32_SETVERSION
287 
288 /*
289  * Structure of an inode on the disk
290  */
291 struct ext2_inode {
292 	__le16	i_mode;		/* File mode */
293 	__le16	i_uid;		/* Low 16 bits of Owner Uid */
294 	__le32	i_size;		/* Size in bytes */
295 	__le32	i_atime;	/* Access time */
296 	__le32	i_ctime;	/* Creation time */
297 	__le32	i_mtime;	/* Modification time */
298 	__le32	i_dtime;	/* Deletion Time */
299 	__le16	i_gid;		/* Low 16 bits of Group Id */
300 	__le16	i_links_count;	/* Links count */
301 	__le32	i_blocks;	/* Blocks count */
302 	__le32	i_flags;	/* File flags */
303 	union {
304 		struct {
305 			__le32  l_i_reserved1;
306 		} linux1;
307 		struct {
308 			__le32  h_i_translator;
309 		} hurd1;
310 		struct {
311 			__le32  m_i_reserved1;
312 		} masix1;
313 	} osd1;				/* OS dependent 1 */
314 	__le32	i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
315 	__le32	i_generation;	/* File version (for NFS) */
316 	__le32	i_file_acl;	/* File ACL */
317 	__le32	i_dir_acl;	/* Directory ACL */
318 	__le32	i_faddr;	/* Fragment address */
319 	union {
320 		struct {
321 			__u8	l_i_frag;	/* Fragment number */
322 			__u8	l_i_fsize;	/* Fragment size */
323 			__u16	i_pad1;
324 			__le16	l_i_uid_high;	/* these 2 fields    */
325 			__le16	l_i_gid_high;	/* were reserved2[0] */
326 			__u32	l_i_reserved2;
327 		} linux2;
328 		struct {
329 			__u8	h_i_frag;	/* Fragment number */
330 			__u8	h_i_fsize;	/* Fragment size */
331 			__le16	h_i_mode_high;
332 			__le16	h_i_uid_high;
333 			__le16	h_i_gid_high;
334 			__le32	h_i_author;
335 		} hurd2;
336 		struct {
337 			__u8	m_i_frag;	/* Fragment number */
338 			__u8	m_i_fsize;	/* Fragment size */
339 			__u16	m_pad1;
340 			__u32	m_i_reserved2[2];
341 		} masix2;
342 	} osd2;				/* OS dependent 2 */
343 };
344 
345 #define i_size_high	i_dir_acl
346 
347 #define i_reserved1	osd1.linux1.l_i_reserved1
348 #define i_frag		osd2.linux2.l_i_frag
349 #define i_fsize		osd2.linux2.l_i_fsize
350 #define i_uid_low	i_uid
351 #define i_gid_low	i_gid
352 #define i_uid_high	osd2.linux2.l_i_uid_high
353 #define i_gid_high	osd2.linux2.l_i_gid_high
354 #define i_reserved2	osd2.linux2.l_i_reserved2
355 
356 /*
357  * File system states
358  */
359 #define	EXT2_VALID_FS			0x0001	/* Unmounted cleanly */
360 #define	EXT2_ERROR_FS			0x0002	/* Errors detected */
361 #define	EFSCORRUPTED			EUCLEAN	/* Filesystem is corrupted */
362 
363 /*
364  * Mount flags
365  */
366 #define EXT2_MOUNT_OLDALLOC		0x000002  /* Don't use the new Orlov allocator */
367 #define EXT2_MOUNT_GRPID		0x000004  /* Create files with directory's group */
368 #define EXT2_MOUNT_DEBUG		0x000008  /* Some debugging messages */
369 #define EXT2_MOUNT_ERRORS_CONT		0x000010  /* Continue on errors */
370 #define EXT2_MOUNT_ERRORS_RO		0x000020  /* Remount fs ro on errors */
371 #define EXT2_MOUNT_ERRORS_PANIC		0x000040  /* Panic on errors */
372 #define EXT2_MOUNT_MINIX_DF		0x000080  /* Mimics the Minix statfs */
373 #define EXT2_MOUNT_NOBH			0x000100  /* No buffer_heads */
374 #define EXT2_MOUNT_NO_UID32		0x000200  /* Disable 32-bit UIDs */
375 #define EXT2_MOUNT_XATTR_USER		0x004000  /* Extended user attributes */
376 #define EXT2_MOUNT_POSIX_ACL		0x008000  /* POSIX Access Control Lists */
377 #define EXT2_MOUNT_XIP			0x010000  /* Obsolete, use DAX */
378 #define EXT2_MOUNT_USRQUOTA		0x020000  /* user quota */
379 #define EXT2_MOUNT_GRPQUOTA		0x040000  /* group quota */
380 #define EXT2_MOUNT_RESERVATION		0x080000  /* Preallocation */
381 #define EXT2_MOUNT_DAX			0x100000  /* Direct Access */
382 
383 
384 #define clear_opt(o, opt)		o &= ~EXT2_MOUNT_##opt
385 #define set_opt(o, opt)			o |= EXT2_MOUNT_##opt
386 #define test_opt(sb, opt)		(EXT2_SB(sb)->s_mount_opt & \
387 					 EXT2_MOUNT_##opt)
388 /*
389  * Maximal mount counts between two filesystem checks
390  */
391 #define EXT2_DFL_MAX_MNT_COUNT		20	/* Allow 20 mounts */
392 #define EXT2_DFL_CHECKINTERVAL		0	/* Don't use interval check */
393 
394 /*
395  * Behaviour when detecting errors
396  */
397 #define EXT2_ERRORS_CONTINUE		1	/* Continue execution */
398 #define EXT2_ERRORS_RO			2	/* Remount fs read-only */
399 #define EXT2_ERRORS_PANIC		3	/* Panic */
400 #define EXT2_ERRORS_DEFAULT		EXT2_ERRORS_CONTINUE
401 
402 /*
403  * Structure of the super block
404  */
405 struct ext2_super_block {
406 	__le32	s_inodes_count;		/* Inodes count */
407 	__le32	s_blocks_count;		/* Blocks count */
408 	__le32	s_r_blocks_count;	/* Reserved blocks count */
409 	__le32	s_free_blocks_count;	/* Free blocks count */
410 	__le32	s_free_inodes_count;	/* Free inodes count */
411 	__le32	s_first_data_block;	/* First Data Block */
412 	__le32	s_log_block_size;	/* Block size */
413 	__le32	s_log_frag_size;	/* Fragment size */
414 	__le32	s_blocks_per_group;	/* # Blocks per group */
415 	__le32	s_frags_per_group;	/* # Fragments per group */
416 	__le32	s_inodes_per_group;	/* # Inodes per group */
417 	__le32	s_mtime;		/* Mount time */
418 	__le32	s_wtime;		/* Write time */
419 	__le16	s_mnt_count;		/* Mount count */
420 	__le16	s_max_mnt_count;	/* Maximal mount count */
421 	__le16	s_magic;		/* Magic signature */
422 	__le16	s_state;		/* File system state */
423 	__le16	s_errors;		/* Behaviour when detecting errors */
424 	__le16	s_minor_rev_level; 	/* minor revision level */
425 	__le32	s_lastcheck;		/* time of last check */
426 	__le32	s_checkinterval;	/* max. time between checks */
427 	__le32	s_creator_os;		/* OS */
428 	__le32	s_rev_level;		/* Revision level */
429 	__le16	s_def_resuid;		/* Default uid for reserved blocks */
430 	__le16	s_def_resgid;		/* Default gid for reserved blocks */
431 	/*
432 	 * These fields are for EXT2_DYNAMIC_REV superblocks only.
433 	 *
434 	 * Note: the difference between the compatible feature set and
435 	 * the incompatible feature set is that if there is a bit set
436 	 * in the incompatible feature set that the kernel doesn't
437 	 * know about, it should refuse to mount the filesystem.
438 	 *
439 	 * e2fsck's requirements are more strict; if it doesn't know
440 	 * about a feature in either the compatible or incompatible
441 	 * feature set, it must abort and not try to meddle with
442 	 * things it doesn't understand...
443 	 */
444 	__le32	s_first_ino; 		/* First non-reserved inode */
445 	__le16   s_inode_size; 		/* size of inode structure */
446 	__le16	s_block_group_nr; 	/* block group # of this superblock */
447 	__le32	s_feature_compat; 	/* compatible feature set */
448 	__le32	s_feature_incompat; 	/* incompatible feature set */
449 	__le32	s_feature_ro_compat; 	/* readonly-compatible feature set */
450 	__u8	s_uuid[16];		/* 128-bit uuid for volume */
451 	char	s_volume_name[16]; 	/* volume name */
452 	char	s_last_mounted[64]; 	/* directory where last mounted */
453 	__le32	s_algorithm_usage_bitmap; /* For compression */
454 	/*
455 	 * Performance hints.  Directory preallocation should only
456 	 * happen if the EXT2_COMPAT_PREALLOC flag is on.
457 	 */
458 	__u8	s_prealloc_blocks;	/* Nr of blocks to try to preallocate*/
459 	__u8	s_prealloc_dir_blocks;	/* Nr to preallocate for dirs */
460 	__u16	s_padding1;
461 	/*
462 	 * Journaling support valid if EXT3_FEATURE_COMPAT_HAS_JOURNAL set.
463 	 */
464 	__u8	s_journal_uuid[16];	/* uuid of journal superblock */
465 	__u32	s_journal_inum;		/* inode number of journal file */
466 	__u32	s_journal_dev;		/* device number of journal file */
467 	__u32	s_last_orphan;		/* start of list of inodes to delete */
468 	__u32	s_hash_seed[4];		/* HTREE hash seed */
469 	__u8	s_def_hash_version;	/* Default hash version to use */
470 	__u8	s_reserved_char_pad;
471 	__u16	s_reserved_word_pad;
472 	__le32	s_default_mount_opts;
473  	__le32	s_first_meta_bg; 	/* First metablock block group */
474 	__u32	s_reserved[190];	/* Padding to the end of the block */
475 };
476 
477 /*
478  * Codes for operating systems
479  */
480 #define EXT2_OS_LINUX		0
481 #define EXT2_OS_HURD		1
482 #define EXT2_OS_MASIX		2
483 #define EXT2_OS_FREEBSD		3
484 #define EXT2_OS_LITES		4
485 
486 /*
487  * Revision levels
488  */
489 #define EXT2_GOOD_OLD_REV	0	/* The good old (original) format */
490 #define EXT2_DYNAMIC_REV	1 	/* V2 format w/ dynamic inode sizes */
491 
492 #define EXT2_CURRENT_REV	EXT2_GOOD_OLD_REV
493 #define EXT2_MAX_SUPP_REV	EXT2_DYNAMIC_REV
494 
495 #define EXT2_GOOD_OLD_INODE_SIZE 128
496 
497 /*
498  * Feature set definitions
499  */
500 
501 #define EXT2_HAS_COMPAT_FEATURE(sb,mask)			\
502 	( EXT2_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask) )
503 #define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask)			\
504 	( EXT2_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask) )
505 #define EXT2_HAS_INCOMPAT_FEATURE(sb,mask)			\
506 	( EXT2_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask) )
507 #define EXT2_SET_COMPAT_FEATURE(sb,mask)			\
508 	EXT2_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
509 #define EXT2_SET_RO_COMPAT_FEATURE(sb,mask)			\
510 	EXT2_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
511 #define EXT2_SET_INCOMPAT_FEATURE(sb,mask)			\
512 	EXT2_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
513 #define EXT2_CLEAR_COMPAT_FEATURE(sb,mask)			\
514 	EXT2_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
515 #define EXT2_CLEAR_RO_COMPAT_FEATURE(sb,mask)			\
516 	EXT2_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
517 #define EXT2_CLEAR_INCOMPAT_FEATURE(sb,mask)			\
518 	EXT2_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
519 
520 #define EXT2_FEATURE_COMPAT_DIR_PREALLOC	0x0001
521 #define EXT2_FEATURE_COMPAT_IMAGIC_INODES	0x0002
522 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL		0x0004
523 #define EXT2_FEATURE_COMPAT_EXT_ATTR		0x0008
524 #define EXT2_FEATURE_COMPAT_RESIZE_INO		0x0010
525 #define EXT2_FEATURE_COMPAT_DIR_INDEX		0x0020
526 #define EXT2_FEATURE_COMPAT_ANY			0xffffffff
527 
528 #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
529 #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
530 #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR	0x0004
531 #define EXT2_FEATURE_RO_COMPAT_ANY		0xffffffff
532 
533 #define EXT2_FEATURE_INCOMPAT_COMPRESSION	0x0001
534 #define EXT2_FEATURE_INCOMPAT_FILETYPE		0x0002
535 #define EXT3_FEATURE_INCOMPAT_RECOVER		0x0004
536 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008
537 #define EXT2_FEATURE_INCOMPAT_META_BG		0x0010
538 #define EXT2_FEATURE_INCOMPAT_ANY		0xffffffff
539 
540 #define EXT2_FEATURE_COMPAT_SUPP	EXT2_FEATURE_COMPAT_EXT_ATTR
541 #define EXT2_FEATURE_INCOMPAT_SUPP	(EXT2_FEATURE_INCOMPAT_FILETYPE| \
542 					 EXT2_FEATURE_INCOMPAT_META_BG)
543 #define EXT2_FEATURE_RO_COMPAT_SUPP	(EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
544 					 EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
545 					 EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
546 #define EXT2_FEATURE_RO_COMPAT_UNSUPPORTED	~EXT2_FEATURE_RO_COMPAT_SUPP
547 #define EXT2_FEATURE_INCOMPAT_UNSUPPORTED	~EXT2_FEATURE_INCOMPAT_SUPP
548 
549 /*
550  * Default values for user and/or group using reserved blocks
551  */
552 #define	EXT2_DEF_RESUID		0
553 #define	EXT2_DEF_RESGID		0
554 
555 /*
556  * Default mount options
557  */
558 #define EXT2_DEFM_DEBUG		0x0001
559 #define EXT2_DEFM_BSDGROUPS	0x0002
560 #define EXT2_DEFM_XATTR_USER	0x0004
561 #define EXT2_DEFM_ACL		0x0008
562 #define EXT2_DEFM_UID16		0x0010
563     /* Not used by ext2, but reserved for use by ext3 */
564 #define EXT3_DEFM_JMODE		0x0060
565 #define EXT3_DEFM_JMODE_DATA	0x0020
566 #define EXT3_DEFM_JMODE_ORDERED	0x0040
567 #define EXT3_DEFM_JMODE_WBACK	0x0060
568 
569 /*
570  * Structure of a directory entry
571  */
572 
573 struct ext2_dir_entry {
574 	__le32	inode;			/* Inode number */
575 	__le16	rec_len;		/* Directory entry length */
576 	__le16	name_len;		/* Name length */
577 	char	name[];			/* File name, up to EXT2_NAME_LEN */
578 };
579 
580 /*
581  * The new version of the directory entry.  Since EXT2 structures are
582  * stored in intel byte order, and the name_len field could never be
583  * bigger than 255 chars, it's safe to reclaim the extra byte for the
584  * file_type field.
585  */
586 struct ext2_dir_entry_2 {
587 	__le32	inode;			/* Inode number */
588 	__le16	rec_len;		/* Directory entry length */
589 	__u8	name_len;		/* Name length */
590 	__u8	file_type;
591 	char	name[];			/* File name, up to EXT2_NAME_LEN */
592 };
593 
594 /*
595  * EXT2_DIR_PAD defines the directory entries boundaries
596  *
597  * NOTE: It must be a multiple of 4
598  */
599 #define EXT2_DIR_PAD		 	4
600 #define EXT2_DIR_ROUND 			(EXT2_DIR_PAD - 1)
601 #define EXT2_DIR_REC_LEN(name_len)	(((name_len) + 8 + EXT2_DIR_ROUND) & \
602 					 ~EXT2_DIR_ROUND)
603 #define EXT2_MAX_REC_LEN		((1<<16)-1)
604 
verify_offsets(void)605 static inline void verify_offsets(void)
606 {
607 #define A(x,y) BUILD_BUG_ON(x != offsetof(struct ext2_super_block, y));
608 	A(EXT2_SB_MAGIC_OFFSET, s_magic);
609 	A(EXT2_SB_BLOCKS_OFFSET, s_blocks_count);
610 	A(EXT2_SB_BSIZE_OFFSET, s_log_block_size);
611 #undef A
612 }
613 
614 /*
615  * ext2 mount options
616  */
617 struct ext2_mount_options {
618 	unsigned long s_mount_opt;
619 	kuid_t s_resuid;
620 	kgid_t s_resgid;
621 };
622 
623 /*
624  * second extended file system inode data in memory
625  */
626 struct ext2_inode_info {
627 	__le32	i_data[15];
628 	__u32	i_flags;
629 	__u32	i_faddr;
630 	__u8	i_frag_no;
631 	__u8	i_frag_size;
632 	__u16	i_state;
633 	__u32	i_file_acl;
634 	__u32	i_dir_acl;
635 	__u32	i_dtime;
636 
637 	/*
638 	 * i_block_group is the number of the block group which contains
639 	 * this file's inode.  Constant across the lifetime of the inode,
640 	 * it is used for making block allocation decisions - we try to
641 	 * place a file's data blocks near its inode block, and new inodes
642 	 * near to their parent directory's inode.
643 	 */
644 	__u32	i_block_group;
645 
646 	/* block reservation info */
647 	struct ext2_block_alloc_info *i_block_alloc_info;
648 
649 	__u32	i_dir_start_lookup;
650 #ifdef CONFIG_EXT2_FS_XATTR
651 	/*
652 	 * Extended attributes can be read independently of the main file
653 	 * data. Taking i_mutex even when reading would cause contention
654 	 * between readers of EAs and writers of regular file data, so
655 	 * instead we synchronize on xattr_sem when reading or changing
656 	 * EAs.
657 	 */
658 	struct rw_semaphore xattr_sem;
659 #endif
660 	rwlock_t i_meta_lock;
661 #ifdef CONFIG_FS_DAX
662 	struct rw_semaphore dax_sem;
663 #endif
664 
665 	/*
666 	 * truncate_mutex is for serialising ext2_truncate() against
667 	 * ext2_getblock().  It also protects the internals of the inode's
668 	 * reservation data structures: ext2_reserve_window and
669 	 * ext2_reserve_window_node.
670 	 */
671 	struct mutex truncate_mutex;
672 	struct inode	vfs_inode;
673 	struct list_head i_orphan;	/* unlinked but open inodes */
674 #ifdef CONFIG_QUOTA
675 	struct dquot *i_dquot[MAXQUOTAS];
676 #endif
677 };
678 
679 #ifdef CONFIG_FS_DAX
680 #define dax_sem_down_write(ext2_inode)	down_write(&(ext2_inode)->dax_sem)
681 #define dax_sem_up_write(ext2_inode)	up_write(&(ext2_inode)->dax_sem)
682 #else
683 #define dax_sem_down_write(ext2_inode)
684 #define dax_sem_up_write(ext2_inode)
685 #endif
686 
687 /*
688  * Inode dynamic state flags
689  */
690 #define EXT2_STATE_NEW			0x00000001 /* inode is newly created */
691 
692 
693 /*
694  * Function prototypes
695  */
696 
697 /*
698  * Ok, these declarations are also in <linux/kernel.h> but none of the
699  * ext2 source programs needs to include it so they are duplicated here.
700  */
701 
EXT2_I(struct inode * inode)702 static inline struct ext2_inode_info *EXT2_I(struct inode *inode)
703 {
704 	return container_of(inode, struct ext2_inode_info, vfs_inode);
705 }
706 
707 /* balloc.c */
708 extern int ext2_bg_has_super(struct super_block *sb, int group);
709 extern unsigned long ext2_bg_num_gdb(struct super_block *sb, int group);
710 extern ext2_fsblk_t ext2_new_block(struct inode *, unsigned long, int *);
711 extern ext2_fsblk_t ext2_new_blocks(struct inode *, unsigned long,
712 				unsigned long *, int *);
713 extern int ext2_data_block_valid(struct ext2_sb_info *sbi, ext2_fsblk_t start_blk,
714 				 unsigned int count);
715 extern void ext2_free_blocks (struct inode *, unsigned long,
716 			      unsigned long);
717 extern unsigned long ext2_count_free_blocks (struct super_block *);
718 extern unsigned long ext2_count_dirs (struct super_block *);
719 extern struct ext2_group_desc * ext2_get_group_desc(struct super_block * sb,
720 						    unsigned int block_group,
721 						    struct buffer_head ** bh);
722 extern void ext2_discard_reservation (struct inode *);
723 extern int ext2_should_retry_alloc(struct super_block *sb, int *retries);
724 extern void ext2_init_block_alloc_info(struct inode *);
725 extern void ext2_rsv_window_add(struct super_block *sb, struct ext2_reserve_window_node *rsv);
726 
727 /* dir.c */
728 extern int ext2_add_link (struct dentry *, struct inode *);
729 extern int ext2_inode_by_name(struct inode *dir,
730 			      const struct qstr *child, ino_t *ino);
731 extern int ext2_make_empty(struct inode *, struct inode *);
732 extern struct ext2_dir_entry_2 * ext2_find_entry (struct inode *,const struct qstr *, struct page **);
733 extern int ext2_delete_entry (struct ext2_dir_entry_2 *, struct page *);
734 extern int ext2_empty_dir (struct inode *);
735 extern struct ext2_dir_entry_2 * ext2_dotdot (struct inode *, struct page **);
736 extern void ext2_set_link(struct inode *, struct ext2_dir_entry_2 *, struct page *, struct inode *, int);
737 
738 /* ialloc.c */
739 extern struct inode * ext2_new_inode (struct inode *, umode_t, const struct qstr *);
740 extern void ext2_free_inode (struct inode *);
741 extern unsigned long ext2_count_free_inodes (struct super_block *);
742 extern unsigned long ext2_count_free (struct buffer_head *, unsigned);
743 
744 /* inode.c */
745 extern struct inode *ext2_iget (struct super_block *, unsigned long);
746 extern int ext2_write_inode (struct inode *, struct writeback_control *);
747 extern void ext2_evict_inode(struct inode *);
748 extern int ext2_get_block(struct inode *, sector_t, struct buffer_head *, int);
749 extern int ext2_setattr (struct dentry *, struct iattr *);
750 extern int ext2_getattr (const struct path *, struct kstat *, u32, unsigned int);
751 extern void ext2_set_inode_flags(struct inode *inode);
752 extern int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
753 		       u64 start, u64 len);
754 
755 /* ioctl.c */
756 extern long ext2_ioctl(struct file *, unsigned int, unsigned long);
757 extern long ext2_compat_ioctl(struct file *, unsigned int, unsigned long);
758 
759 /* namei.c */
760 struct dentry *ext2_get_parent(struct dentry *child);
761 
762 /* super.c */
763 extern __printf(3, 4)
764 void ext2_error(struct super_block *, const char *, const char *, ...);
765 extern __printf(3, 4)
766 void ext2_msg(struct super_block *, const char *, const char *, ...);
767 extern void ext2_update_dynamic_rev (struct super_block *sb);
768 extern void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
769 			    int wait);
770 
771 /*
772  * Inodes and files operations
773  */
774 
775 /* dir.c */
776 extern const struct file_operations ext2_dir_operations;
777 
778 /* file.c */
779 extern int ext2_fsync(struct file *file, loff_t start, loff_t end,
780 		      int datasync);
781 extern const struct inode_operations ext2_file_inode_operations;
782 extern const struct file_operations ext2_file_operations;
783 
784 /* inode.c */
785 extern void ext2_set_file_ops(struct inode *inode);
786 extern const struct address_space_operations ext2_aops;
787 extern const struct address_space_operations ext2_nobh_aops;
788 extern const struct iomap_ops ext2_iomap_ops;
789 
790 /* namei.c */
791 extern const struct inode_operations ext2_dir_inode_operations;
792 extern const struct inode_operations ext2_special_inode_operations;
793 
794 /* symlink.c */
795 extern const struct inode_operations ext2_fast_symlink_inode_operations;
796 extern const struct inode_operations ext2_symlink_inode_operations;
797 
798 static inline ext2_fsblk_t
ext2_group_first_block_no(struct super_block * sb,unsigned long group_no)799 ext2_group_first_block_no(struct super_block *sb, unsigned long group_no)
800 {
801 	return group_no * (ext2_fsblk_t)EXT2_BLOCKS_PER_GROUP(sb) +
802 		le32_to_cpu(EXT2_SB(sb)->s_es->s_first_data_block);
803 }
804 
805 static inline ext2_fsblk_t
ext2_group_last_block_no(struct super_block * sb,unsigned long group_no)806 ext2_group_last_block_no(struct super_block *sb, unsigned long group_no)
807 {
808 	struct ext2_sb_info *sbi = EXT2_SB(sb);
809 
810 	if (group_no == sbi->s_groups_count - 1)
811 		return le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
812 	else
813 		return ext2_group_first_block_no(sb, group_no) +
814 			EXT2_BLOCKS_PER_GROUP(sb) - 1;
815 }
816 
817 #define ext2_set_bit	__test_and_set_bit_le
818 #define ext2_clear_bit	__test_and_clear_bit_le
819 #define ext2_test_bit	test_bit_le
820 #define ext2_find_first_zero_bit	find_first_zero_bit_le
821 #define ext2_find_next_zero_bit		find_next_zero_bit_le
822