ext2.h

  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 */
 25typedef int ext2_grpblk_t;
 26
 27/* data type for filesystem-wide blocks number */
 28typedef unsigned long ext2_fsblk_t;
 29
 30#define E2FSBLK "%lu"
 31
 32struct 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
 37struct 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
 44struct 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
 67struct mb_cache;
 68
 69/*
 70 * second extended-fs super-block data in memory
 71 */
 72struct 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
121static inline spinlock_t *
122sb_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
169static 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 */
191struct 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. */
263static 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 */
290struct 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_ERRORS_MASK		0x000070
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 * Allocation flags
404 */
405#define EXT2_ALLOC_NORESERVE            0x1	/* Do not use reservation
406						 * window for allocation */
407
408/*
409 * Structure of the super block
410 */
411struct ext2_super_block {
412	__le32	s_inodes_count;		/* Inodes count */
413	__le32	s_blocks_count;		/* Blocks count */
414	__le32	s_r_blocks_count;	/* Reserved blocks count */
415	__le32	s_free_blocks_count;	/* Free blocks count */
416	__le32	s_free_inodes_count;	/* Free inodes count */
417	__le32	s_first_data_block;	/* First Data Block */
418	__le32	s_log_block_size;	/* Block size */
419	__le32	s_log_frag_size;	/* Fragment size */
420	__le32	s_blocks_per_group;	/* # Blocks per group */
421	__le32	s_frags_per_group;	/* # Fragments per group */
422	__le32	s_inodes_per_group;	/* # Inodes per group */
423	__le32	s_mtime;		/* Mount time */
424	__le32	s_wtime;		/* Write time */
425	__le16	s_mnt_count;		/* Mount count */
426	__le16	s_max_mnt_count;	/* Maximal mount count */
427	__le16	s_magic;		/* Magic signature */
428	__le16	s_state;		/* File system state */
429	__le16	s_errors;		/* Behaviour when detecting errors */
430	__le16	s_minor_rev_level; 	/* minor revision level */
431	__le32	s_lastcheck;		/* time of last check */
432	__le32	s_checkinterval;	/* max. time between checks */
433	__le32	s_creator_os;		/* OS */
434	__le32	s_rev_level;		/* Revision level */
435	__le16	s_def_resuid;		/* Default uid for reserved blocks */
436	__le16	s_def_resgid;		/* Default gid for reserved blocks */
437	/*
438	 * These fields are for EXT2_DYNAMIC_REV superblocks only.
439	 *
440	 * Note: the difference between the compatible feature set and
441	 * the incompatible feature set is that if there is a bit set
442	 * in the incompatible feature set that the kernel doesn't
443	 * know about, it should refuse to mount the filesystem.
444	 * 
445	 * e2fsck's requirements are more strict; if it doesn't know
446	 * about a feature in either the compatible or incompatible
447	 * feature set, it must abort and not try to meddle with
448	 * things it doesn't understand...
449	 */
450	__le32	s_first_ino; 		/* First non-reserved inode */
451	__le16   s_inode_size; 		/* size of inode structure */
452	__le16	s_block_group_nr; 	/* block group # of this superblock */
453	__le32	s_feature_compat; 	/* compatible feature set */
454	__le32	s_feature_incompat; 	/* incompatible feature set */
455	__le32	s_feature_ro_compat; 	/* readonly-compatible feature set */
456	__u8	s_uuid[16];		/* 128-bit uuid for volume */
457	char	s_volume_name[16]; 	/* volume name */
458	char	s_last_mounted[64]; 	/* directory where last mounted */
459	__le32	s_algorithm_usage_bitmap; /* For compression */
460	/*
461	 * Performance hints.  Directory preallocation should only
462	 * happen if the EXT2_COMPAT_PREALLOC flag is on.
463	 */
464	__u8	s_prealloc_blocks;	/* Nr of blocks to try to preallocate*/
465	__u8	s_prealloc_dir_blocks;	/* Nr to preallocate for dirs */
466	__u16	s_padding1;
467	/*
468	 * Journaling support valid if EXT3_FEATURE_COMPAT_HAS_JOURNAL set.
469	 */
470	__u8	s_journal_uuid[16];	/* uuid of journal superblock */
471	__u32	s_journal_inum;		/* inode number of journal file */
472	__u32	s_journal_dev;		/* device number of journal file */
473	__u32	s_last_orphan;		/* start of list of inodes to delete */
474	__u32	s_hash_seed[4];		/* HTREE hash seed */
475	__u8	s_def_hash_version;	/* Default hash version to use */
476	__u8	s_reserved_char_pad;
477	__u16	s_reserved_word_pad;
478	__le32	s_default_mount_opts;
479 	__le32	s_first_meta_bg; 	/* First metablock block group */
480	__u32	s_reserved[190];	/* Padding to the end of the block */
481};
482
483/*
484 * Codes for operating systems
485 */
486#define EXT2_OS_LINUX		0
487#define EXT2_OS_HURD		1
488#define EXT2_OS_MASIX		2
489#define EXT2_OS_FREEBSD		3
490#define EXT2_OS_LITES		4
491
492/*
493 * Revision levels
494 */
495#define EXT2_GOOD_OLD_REV	0	/* The good old (original) format */
496#define EXT2_DYNAMIC_REV	1 	/* V2 format w/ dynamic inode sizes */
497
498#define EXT2_CURRENT_REV	EXT2_GOOD_OLD_REV
499#define EXT2_MAX_SUPP_REV	EXT2_DYNAMIC_REV
500
501#define EXT2_GOOD_OLD_INODE_SIZE 128
502
503/*
504 * Feature set definitions
505 */
506
507#define EXT2_HAS_COMPAT_FEATURE(sb,mask)			\
508	( EXT2_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask) )
509#define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask)			\
510	( EXT2_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask) )
511#define EXT2_HAS_INCOMPAT_FEATURE(sb,mask)			\
512	( EXT2_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask) )
513#define EXT2_SET_COMPAT_FEATURE(sb,mask)			\
514	EXT2_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
515#define EXT2_SET_RO_COMPAT_FEATURE(sb,mask)			\
516	EXT2_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
517#define EXT2_SET_INCOMPAT_FEATURE(sb,mask)			\
518	EXT2_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
519#define EXT2_CLEAR_COMPAT_FEATURE(sb,mask)			\
520	EXT2_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
521#define EXT2_CLEAR_RO_COMPAT_FEATURE(sb,mask)			\
522	EXT2_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
523#define EXT2_CLEAR_INCOMPAT_FEATURE(sb,mask)			\
524	EXT2_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
525
526#define EXT2_FEATURE_COMPAT_DIR_PREALLOC	0x0001
527#define EXT2_FEATURE_COMPAT_IMAGIC_INODES	0x0002
528#define EXT3_FEATURE_COMPAT_HAS_JOURNAL		0x0004
529#define EXT2_FEATURE_COMPAT_EXT_ATTR		0x0008
530#define EXT2_FEATURE_COMPAT_RESIZE_INO		0x0010
531#define EXT2_FEATURE_COMPAT_DIR_INDEX		0x0020
532#define EXT2_FEATURE_COMPAT_ANY			0xffffffff
533
534#define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
535#define EXT2_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
536#define EXT2_FEATURE_RO_COMPAT_BTREE_DIR	0x0004
537#define EXT2_FEATURE_RO_COMPAT_ANY		0xffffffff
538
539#define EXT2_FEATURE_INCOMPAT_COMPRESSION	0x0001
540#define EXT2_FEATURE_INCOMPAT_FILETYPE		0x0002
541#define EXT3_FEATURE_INCOMPAT_RECOVER		0x0004
542#define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008
543#define EXT2_FEATURE_INCOMPAT_META_BG		0x0010
544#define EXT2_FEATURE_INCOMPAT_ANY		0xffffffff
545
546#define EXT2_FEATURE_COMPAT_SUPP	EXT2_FEATURE_COMPAT_EXT_ATTR
547#define EXT2_FEATURE_INCOMPAT_SUPP	(EXT2_FEATURE_INCOMPAT_FILETYPE| \
548					 EXT2_FEATURE_INCOMPAT_META_BG)
549#define EXT2_FEATURE_RO_COMPAT_SUPP	(EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
550					 EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
551					 EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
552#define EXT2_FEATURE_RO_COMPAT_UNSUPPORTED	~EXT2_FEATURE_RO_COMPAT_SUPP
553#define EXT2_FEATURE_INCOMPAT_UNSUPPORTED	~EXT2_FEATURE_INCOMPAT_SUPP
554
555/*
556 * Default values for user and/or group using reserved blocks
557 */
558#define	EXT2_DEF_RESUID		0
559#define	EXT2_DEF_RESGID		0
560
561/*
562 * Default mount options
563 */
564#define EXT2_DEFM_DEBUG		0x0001
565#define EXT2_DEFM_BSDGROUPS	0x0002
566#define EXT2_DEFM_XATTR_USER	0x0004
567#define EXT2_DEFM_ACL		0x0008
568#define EXT2_DEFM_UID16		0x0010
569    /* Not used by ext2, but reserved for use by ext3 */
570#define EXT3_DEFM_JMODE		0x0060 
571#define EXT3_DEFM_JMODE_DATA	0x0020
572#define EXT3_DEFM_JMODE_ORDERED	0x0040
573#define EXT3_DEFM_JMODE_WBACK	0x0060
574
575/*
576 * Structure of a directory entry
577 */
578
579struct ext2_dir_entry {
580	__le32	inode;			/* Inode number */
581	__le16	rec_len;		/* Directory entry length */
582	__le16	name_len;		/* Name length */
583	char	name[];			/* File name, up to EXT2_NAME_LEN */
584};
585
586/*
587 * The new version of the directory entry.  Since EXT2 structures are
588 * stored in intel byte order, and the name_len field could never be
589 * bigger than 255 chars, it's safe to reclaim the extra byte for the
590 * file_type field.
591 */
592struct ext2_dir_entry_2 {
593	__le32	inode;			/* Inode number */
594	__le16	rec_len;		/* Directory entry length */
595	__u8	name_len;		/* Name length */
596	__u8	file_type;
597	char	name[];			/* File name, up to EXT2_NAME_LEN */
598};
599
600/*
601 * EXT2_DIR_PAD defines the directory entries boundaries
602 *
603 * NOTE: It must be a multiple of 4
604 */
605#define EXT2_DIR_PAD		 	4
606#define EXT2_DIR_ROUND 			(EXT2_DIR_PAD - 1)
607#define EXT2_DIR_REC_LEN(name_len)	(((name_len) + 8 + EXT2_DIR_ROUND) & \
608					 ~EXT2_DIR_ROUND)
609#define EXT2_MAX_REC_LEN		((1<<16)-1)
610
611static inline void verify_offsets(void)
612{
613#define A(x,y) BUILD_BUG_ON(x != offsetof(struct ext2_super_block, y));
614	A(EXT2_SB_MAGIC_OFFSET, s_magic);
615	A(EXT2_SB_BLOCKS_OFFSET, s_blocks_count);
616	A(EXT2_SB_BSIZE_OFFSET, s_log_block_size);
617#undef A
618}
619
620/*
621 * ext2 mount options
622 */
623struct ext2_mount_options {
624	unsigned long s_mount_opt;
625	kuid_t s_resuid;
626	kgid_t s_resgid;
627};
628
629/*
630 * second extended file system inode data in memory
631 */
632struct ext2_inode_info {
633	__le32	i_data[15];
634	__u32	i_flags;
635	__u32	i_faddr;
636	__u8	i_frag_no;
637	__u8	i_frag_size;
638	__u16	i_state;
639	__u32	i_file_acl;
640	__u32	i_dir_acl;
641	__u32	i_dtime;
642
643	/*
644	 * i_block_group is the number of the block group which contains
645	 * this file's inode.  Constant across the lifetime of the inode,
646	 * it is used for making block allocation decisions - we try to
647	 * place a file's data blocks near its inode block, and new inodes
648	 * near to their parent directory's inode.
649	 */
650	__u32	i_block_group;
651
652	/* block reservation info */
653	struct ext2_block_alloc_info *i_block_alloc_info;
654
655	__u32	i_dir_start_lookup;
656#ifdef CONFIG_EXT2_FS_XATTR
657	/*
658	 * Extended attributes can be read independently of the main file
659	 * data. Taking i_mutex even when reading would cause contention
660	 * between readers of EAs and writers of regular file data, so
661	 * instead we synchronize on xattr_sem when reading or changing
662	 * EAs.
663	 */
664	struct rw_semaphore xattr_sem;
665#endif
666	rwlock_t i_meta_lock;
667
668	/*
669	 * truncate_mutex is for serialising ext2_truncate() against
670	 * ext2_getblock().  It also protects the internals of the inode's
671	 * reservation data structures: ext2_reserve_window and
672	 * ext2_reserve_window_node.
673	 */
674	struct mutex truncate_mutex;
675	struct inode	vfs_inode;
676	struct list_head i_orphan;	/* unlinked but open inodes */
677#ifdef CONFIG_QUOTA
678	struct dquot __rcu *i_dquot[MAXQUOTAS];
679#endif
680};
681
682/*
683 * Inode dynamic state flags
684 */
685#define EXT2_STATE_NEW			0x00000001 /* inode is newly created */
686
687
688/*
689 * Function prototypes
690 */
691
692/*
693 * Ok, these declarations are also in <linux/kernel.h> but none of the
694 * ext2 source programs needs to include it so they are duplicated here.
695 */
696
697static inline struct ext2_inode_info *EXT2_I(struct inode *inode)
698{
699	return container_of(inode, struct ext2_inode_info, vfs_inode);
700}
701
702/* balloc.c */
703extern int ext2_bg_has_super(struct super_block *sb, int group);
704extern unsigned long ext2_bg_num_gdb(struct super_block *sb, int group);
705extern ext2_fsblk_t ext2_new_blocks(struct inode *, ext2_fsblk_t,
706				unsigned long *, int *, unsigned int);
707extern int ext2_data_block_valid(struct ext2_sb_info *sbi, ext2_fsblk_t start_blk,
708				 unsigned int count);
709extern void ext2_free_blocks(struct inode *, ext2_fsblk_t, unsigned long);
710extern unsigned long ext2_count_free_blocks (struct super_block *);
711extern unsigned long ext2_count_dirs (struct super_block *);
712extern struct ext2_group_desc * ext2_get_group_desc(struct super_block * sb,
713						    unsigned int block_group,
714						    struct buffer_head ** bh);
715extern void ext2_discard_reservation (struct inode *);
716extern int ext2_should_retry_alloc(struct super_block *sb, int *retries);
717extern void ext2_init_block_alloc_info(struct inode *);
718extern void ext2_rsv_window_add(struct super_block *sb, struct ext2_reserve_window_node *rsv);
719
720/* dir.c */
721int ext2_add_link(struct dentry *, struct inode *);
722int ext2_inode_by_name(struct inode *dir,
723			      const struct qstr *child, ino_t *ino);
724int ext2_make_empty(struct inode *, struct inode *);
725struct ext2_dir_entry_2 *ext2_find_entry(struct inode *, const struct qstr *,
726		struct folio **foliop);
727int ext2_delete_entry(struct ext2_dir_entry_2 *dir, struct folio *folio);
728int ext2_empty_dir(struct inode *);
729struct ext2_dir_entry_2 *ext2_dotdot(struct inode *dir, struct folio **foliop);
730int ext2_set_link(struct inode *dir, struct ext2_dir_entry_2 *de,
731		struct folio *folio, struct inode *inode, bool update_times);
732
733/* ialloc.c */
734extern struct inode * ext2_new_inode (struct inode *, umode_t, const struct qstr *);
735extern void ext2_free_inode (struct inode *);
736extern unsigned long ext2_count_free_inodes (struct super_block *);
737extern unsigned long ext2_count_free (struct buffer_head *, unsigned);
738
739/* inode.c */
740extern struct inode *ext2_iget (struct super_block *, unsigned long);
741extern int ext2_write_inode (struct inode *, struct writeback_control *);
742extern void ext2_evict_inode(struct inode *);
743void ext2_write_failed(struct address_space *mapping, loff_t to);
744extern int ext2_get_block(struct inode *, sector_t, struct buffer_head *, int);
745extern int ext2_setattr (struct mnt_idmap *, struct dentry *, struct iattr *);
746extern int ext2_getattr (struct mnt_idmap *, const struct path *,
747			 struct kstat *, u32, unsigned int);
748extern void ext2_set_inode_flags(struct inode *inode);
749extern int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
750		       u64 start, u64 len);
751
752/* ioctl.c */
753extern int ext2_fileattr_get(struct dentry *dentry, struct file_kattr *fa);
754extern int ext2_fileattr_set(struct mnt_idmap *idmap,
755			     struct dentry *dentry, struct file_kattr *fa);
756extern long ext2_ioctl(struct file *, unsigned int, unsigned long);
757extern long ext2_compat_ioctl(struct file *, unsigned int, unsigned long);
758
759/* namei.c */
760struct dentry *ext2_get_parent(struct dentry *child);
761
762/* super.c */
763extern __printf(3, 4)
764void ext2_error(struct super_block *, const char *, const char *, ...);
765extern __printf(3, 4)
766void ext2_msg(struct super_block *, const char *, const char *, ...);
767extern void ext2_update_dynamic_rev (struct super_block *sb);
768extern 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 */
776extern const struct file_operations ext2_dir_operations;
777
778/* file.c */
779extern int ext2_fsync(struct file *file, loff_t start, loff_t end,
780		      int datasync);
781extern const struct inode_operations ext2_file_inode_operations;
782extern const struct file_operations ext2_file_operations;
783
784/* inode.c */
785extern void ext2_set_file_ops(struct inode *inode);
786extern const struct address_space_operations ext2_aops;
787extern const struct iomap_ops ext2_iomap_ops;
788
789/* namei.c */
790extern const struct inode_operations ext2_dir_inode_operations;
791extern const struct inode_operations ext2_special_inode_operations;
792
793/* symlink.c */
794extern const struct inode_operations ext2_fast_symlink_inode_operations;
795extern const struct inode_operations ext2_symlink_inode_operations;
796
797static inline ext2_fsblk_t
798ext2_group_first_block_no(struct super_block *sb, unsigned long group_no)
799{
800	return group_no * (ext2_fsblk_t)EXT2_BLOCKS_PER_GROUP(sb) +
801		le32_to_cpu(EXT2_SB(sb)->s_es->s_first_data_block);
802}
803
804static inline ext2_fsblk_t
805ext2_group_last_block_no(struct super_block *sb, unsigned long group_no)
806{
807	struct ext2_sb_info *sbi = EXT2_SB(sb);
808
809	if (group_no == sbi->s_groups_count - 1)
810		return le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
811	else
812		return ext2_group_first_block_no(sb, group_no) +
813			EXT2_BLOCKS_PER_GROUP(sb) - 1;
814}
815
816#define ext2_set_bit	__test_and_set_bit_le
817#define ext2_clear_bit	__test_and_clear_bit_le
818#define ext2_test_bit	test_bit_le
819#define ext2_find_first_zero_bit	find_first_zero_bit_le
820#define ext2_find_next_zero_bit		find_next_zero_bit_le