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 *
sb_bgl_lock(struct ext2_sb_info * sbi,unsigned int block_group)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  
EXT2_SB(struct super_block * sb)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. */
ext2_mask_flags(umode_t mode,__u32 flags)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  
verify_offsets(void)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  
EXT2_I(struct inode * inode)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  int ext2_add_link(struct dentry *, struct inode *);
721  int ext2_inode_by_name(struct inode *dir,
722  			      const struct qstr *child, ino_t *ino);
723  int ext2_make_empty(struct inode *, struct inode *);
724  struct ext2_dir_entry_2 *ext2_find_entry(struct inode *, const struct qstr *,
725  		struct folio **foliop);
726  int ext2_delete_entry(struct ext2_dir_entry_2 *dir, struct folio *folio);
727  int ext2_empty_dir(struct inode *);
728  struct ext2_dir_entry_2 *ext2_dotdot(struct inode *dir, struct folio **foliop);
729  int ext2_set_link(struct inode *dir, struct ext2_dir_entry_2 *de,
730  		struct folio *folio, struct inode *inode, bool update_times);
731  
732  /* ialloc.c */
733  extern struct inode * ext2_new_inode (struct inode *, umode_t, const struct qstr *);
734  extern void ext2_free_inode (struct inode *);
735  extern unsigned long ext2_count_free_inodes (struct super_block *);
736  extern unsigned long ext2_count_free (struct buffer_head *, unsigned);
737  
738  /* inode.c */
739  extern struct inode *ext2_iget (struct super_block *, unsigned long);
740  extern int ext2_write_inode (struct inode *, struct writeback_control *);
741  extern void ext2_evict_inode(struct inode *);
742  void ext2_write_failed(struct address_space *mapping, loff_t to);
743  extern int ext2_get_block(struct inode *, sector_t, struct buffer_head *, int);
744  extern int ext2_setattr (struct mnt_idmap *, struct dentry *, struct iattr *);
745  extern int ext2_getattr (struct mnt_idmap *, const struct path *,
746  			 struct kstat *, u32, unsigned int);
747  extern void ext2_set_inode_flags(struct inode *inode);
748  extern int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
749  		       u64 start, u64 len);
750  
751  /* ioctl.c */
752  extern int ext2_fileattr_get(struct dentry *dentry, struct fileattr *fa);
753  extern int ext2_fileattr_set(struct mnt_idmap *idmap,
754  			     struct dentry *dentry, struct fileattr *fa);
755  extern long ext2_ioctl(struct file *, unsigned int, unsigned long);
756  extern long ext2_compat_ioctl(struct file *, unsigned int, unsigned long);
757  
758  /* namei.c */
759  struct dentry *ext2_get_parent(struct dentry *child);
760  
761  /* super.c */
762  extern __printf(3, 4)
763  void ext2_error(struct super_block *, const char *, const char *, ...);
764  extern __printf(3, 4)
765  void ext2_msg(struct super_block *, const char *, const char *, ...);
766  extern void ext2_update_dynamic_rev (struct super_block *sb);
767  extern void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
768  			    int wait);
769  
770  /*
771   * Inodes and files operations
772   */
773  
774  /* dir.c */
775  extern const struct file_operations ext2_dir_operations;
776  
777  /* file.c */
778  extern int ext2_fsync(struct file *file, loff_t start, loff_t end,
779  		      int datasync);
780  extern const struct inode_operations ext2_file_inode_operations;
781  extern const struct file_operations ext2_file_operations;
782  
783  /* inode.c */
784  extern void ext2_set_file_ops(struct inode *inode);
785  extern const struct address_space_operations ext2_aops;
786  extern const struct iomap_ops ext2_iomap_ops;
787  
788  /* namei.c */
789  extern const struct inode_operations ext2_dir_inode_operations;
790  extern const struct inode_operations ext2_special_inode_operations;
791  
792  /* symlink.c */
793  extern const struct inode_operations ext2_fast_symlink_inode_operations;
794  extern const struct inode_operations ext2_symlink_inode_operations;
795  
796  static inline ext2_fsblk_t
ext2_group_first_block_no(struct super_block * sb,unsigned long group_no)797  ext2_group_first_block_no(struct super_block *sb, unsigned long group_no)
798  {
799  	return group_no * (ext2_fsblk_t)EXT2_BLOCKS_PER_GROUP(sb) +
800  		le32_to_cpu(EXT2_SB(sb)->s_es->s_first_data_block);
801  }
802  
803  static inline ext2_fsblk_t
ext2_group_last_block_no(struct super_block * sb,unsigned long group_no)804  ext2_group_last_block_no(struct super_block *sb, unsigned long group_no)
805  {
806  	struct ext2_sb_info *sbi = EXT2_SB(sb);
807  
808  	if (group_no == sbi->s_groups_count - 1)
809  		return le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
810  	else
811  		return ext2_group_first_block_no(sb, group_no) +
812  			EXT2_BLOCKS_PER_GROUP(sb) - 1;
813  }
814  
815  #define ext2_set_bit	__test_and_set_bit_le
816  #define ext2_clear_bit	__test_and_clear_bit_le
817  #define ext2_test_bit	test_bit_le
818  #define ext2_find_first_zero_bit	find_first_zero_bit_le
819  #define ext2_find_next_zero_bit		find_next_zero_bit_le
820