xref: /linux/fs/ext4/ext4.h (revision b8bb76713ec50df2f11efee386e16f93d51e1076)
1 /*
2  *  ext4.h
3  *
4  * Copyright (C) 1992, 1993, 1994, 1995
5  * Remy Card (card@masi.ibp.fr)
6  * Laboratoire MASI - Institut Blaise Pascal
7  * Universite Pierre et Marie Curie (Paris VI)
8  *
9  *  from
10  *
11  *  linux/include/linux/minix_fs.h
12  *
13  *  Copyright (C) 1991, 1992  Linus Torvalds
14  */
15 
16 #ifndef _EXT4_H
17 #define _EXT4_H
18 
19 #include <linux/types.h>
20 #include <linux/blkdev.h>
21 #include <linux/magic.h>
22 #include <linux/jbd2.h>
23 #include <linux/quota.h>
24 #include "ext4_i.h"
25 
26 /*
27  * The fourth extended filesystem constants/structures
28  */
29 
30 /*
31  * Define EXT4FS_DEBUG to produce debug messages
32  */
33 #undef EXT4FS_DEBUG
34 
35 /*
36  * Debug code
37  */
38 #ifdef EXT4FS_DEBUG
39 #define ext4_debug(f, a...)						\
40 	do {								\
41 		printk(KERN_DEBUG "EXT4-fs DEBUG (%s, %d): %s:",	\
42 			__FILE__, __LINE__, __func__);			\
43 		printk(KERN_DEBUG f, ## a);				\
44 	} while (0)
45 #else
46 #define ext4_debug(f, a...)	do {} while (0)
47 #endif
48 
49 /* prefer goal again. length */
50 #define EXT4_MB_HINT_MERGE		1
51 /* blocks already reserved */
52 #define EXT4_MB_HINT_RESERVED		2
53 /* metadata is being allocated */
54 #define EXT4_MB_HINT_METADATA		4
55 /* first blocks in the file */
56 #define EXT4_MB_HINT_FIRST		8
57 /* search for the best chunk */
58 #define EXT4_MB_HINT_BEST		16
59 /* data is being allocated */
60 #define EXT4_MB_HINT_DATA		32
61 /* don't preallocate (for tails) */
62 #define EXT4_MB_HINT_NOPREALLOC		64
63 /* allocate for locality group */
64 #define EXT4_MB_HINT_GROUP_ALLOC	128
65 /* allocate goal blocks or none */
66 #define EXT4_MB_HINT_GOAL_ONLY		256
67 /* goal is meaningful */
68 #define EXT4_MB_HINT_TRY_GOAL		512
69 /* blocks already pre-reserved by delayed allocation */
70 #define EXT4_MB_DELALLOC_RESERVED      1024
71 
72 
73 struct ext4_allocation_request {
74 	/* target inode for block we're allocating */
75 	struct inode *inode;
76 	/* logical block in target inode */
77 	ext4_lblk_t logical;
78 	/* phys. target (a hint) */
79 	ext4_fsblk_t goal;
80 	/* the closest logical allocated block to the left */
81 	ext4_lblk_t lleft;
82 	/* phys. block for ^^^ */
83 	ext4_fsblk_t pleft;
84 	/* the closest logical allocated block to the right */
85 	ext4_lblk_t lright;
86 	/* phys. block for ^^^ */
87 	ext4_fsblk_t pright;
88 	/* how many blocks we want to allocate */
89 	unsigned int len;
90 	/* flags. see above EXT4_MB_HINT_* */
91 	unsigned int flags;
92 };
93 
94 /*
95  * Special inodes numbers
96  */
97 #define	EXT4_BAD_INO		 1	/* Bad blocks inode */
98 #define EXT4_ROOT_INO		 2	/* Root inode */
99 #define EXT4_BOOT_LOADER_INO	 5	/* Boot loader inode */
100 #define EXT4_UNDEL_DIR_INO	 6	/* Undelete directory inode */
101 #define EXT4_RESIZE_INO		 7	/* Reserved group descriptors inode */
102 #define EXT4_JOURNAL_INO	 8	/* Journal inode */
103 
104 /* First non-reserved inode for old ext4 filesystems */
105 #define EXT4_GOOD_OLD_FIRST_INO	11
106 
107 /*
108  * Maximal count of links to a file
109  */
110 #define EXT4_LINK_MAX		65000
111 
112 /*
113  * Macro-instructions used to manage several block sizes
114  */
115 #define EXT4_MIN_BLOCK_SIZE		1024
116 #define	EXT4_MAX_BLOCK_SIZE		65536
117 #define EXT4_MIN_BLOCK_LOG_SIZE		10
118 #ifdef __KERNEL__
119 # define EXT4_BLOCK_SIZE(s)		((s)->s_blocksize)
120 #else
121 # define EXT4_BLOCK_SIZE(s)		(EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
122 #endif
123 #define	EXT4_ADDR_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / sizeof(__u32))
124 #ifdef __KERNEL__
125 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_blocksize_bits)
126 #else
127 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_log_block_size + 10)
128 #endif
129 #ifdef __KERNEL__
130 #define	EXT4_ADDR_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_addr_per_block_bits)
131 #define EXT4_INODE_SIZE(s)		(EXT4_SB(s)->s_inode_size)
132 #define EXT4_FIRST_INO(s)		(EXT4_SB(s)->s_first_ino)
133 #else
134 #define EXT4_INODE_SIZE(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
135 				 EXT4_GOOD_OLD_INODE_SIZE : \
136 				 (s)->s_inode_size)
137 #define EXT4_FIRST_INO(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
138 				 EXT4_GOOD_OLD_FIRST_INO : \
139 				 (s)->s_first_ino)
140 #endif
141 #define EXT4_BLOCK_ALIGN(size, blkbits)		ALIGN((size), (1 << (blkbits)))
142 
143 /*
144  * Structure of a blocks group descriptor
145  */
146 struct ext4_group_desc
147 {
148 	__le32	bg_block_bitmap_lo;	/* Blocks bitmap block */
149 	__le32	bg_inode_bitmap_lo;	/* Inodes bitmap block */
150 	__le32	bg_inode_table_lo;	/* Inodes table block */
151 	__le16	bg_free_blocks_count_lo;/* Free blocks count */
152 	__le16	bg_free_inodes_count_lo;/* Free inodes count */
153 	__le16	bg_used_dirs_count_lo;	/* Directories count */
154 	__le16	bg_flags;		/* EXT4_BG_flags (INODE_UNINIT, etc) */
155 	__u32	bg_reserved[2];		/* Likely block/inode bitmap checksum */
156 	__le16  bg_itable_unused_lo;	/* Unused inodes count */
157 	__le16  bg_checksum;		/* crc16(sb_uuid+group+desc) */
158 	__le32	bg_block_bitmap_hi;	/* Blocks bitmap block MSB */
159 	__le32	bg_inode_bitmap_hi;	/* Inodes bitmap block MSB */
160 	__le32	bg_inode_table_hi;	/* Inodes table block MSB */
161 	__le16	bg_free_blocks_count_hi;/* Free blocks count MSB */
162 	__le16	bg_free_inodes_count_hi;/* Free inodes count MSB */
163 	__le16	bg_used_dirs_count_hi;	/* Directories count MSB */
164 	__le16  bg_itable_unused_hi;    /* Unused inodes count MSB */
165 	__u32	bg_reserved2[3];
166 };
167 
168 /*
169  * Structure of a flex block group info
170  */
171 
172 struct flex_groups {
173 	atomic_t free_inodes;
174 	atomic_t free_blocks;
175 	atomic_t used_dirs;
176 };
177 
178 #define EXT4_BG_INODE_UNINIT	0x0001 /* Inode table/bitmap not in use */
179 #define EXT4_BG_BLOCK_UNINIT	0x0002 /* Block bitmap not in use */
180 #define EXT4_BG_INODE_ZEROED	0x0004 /* On-disk itable initialized to zero */
181 
182 #ifdef __KERNEL__
183 #include "ext4_sb.h"
184 #endif
185 /*
186  * Macro-instructions used to manage group descriptors
187  */
188 #define EXT4_MIN_DESC_SIZE		32
189 #define EXT4_MIN_DESC_SIZE_64BIT	64
190 #define	EXT4_MAX_DESC_SIZE		EXT4_MIN_BLOCK_SIZE
191 #define EXT4_DESC_SIZE(s)		(EXT4_SB(s)->s_desc_size)
192 #ifdef __KERNEL__
193 # define EXT4_BLOCKS_PER_GROUP(s)	(EXT4_SB(s)->s_blocks_per_group)
194 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_SB(s)->s_desc_per_block)
195 # define EXT4_INODES_PER_GROUP(s)	(EXT4_SB(s)->s_inodes_per_group)
196 # define EXT4_DESC_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_desc_per_block_bits)
197 #else
198 # define EXT4_BLOCKS_PER_GROUP(s)	((s)->s_blocks_per_group)
199 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
200 # define EXT4_INODES_PER_GROUP(s)	((s)->s_inodes_per_group)
201 #endif
202 
203 /*
204  * Constants relative to the data blocks
205  */
206 #define	EXT4_NDIR_BLOCKS		12
207 #define	EXT4_IND_BLOCK			EXT4_NDIR_BLOCKS
208 #define	EXT4_DIND_BLOCK			(EXT4_IND_BLOCK + 1)
209 #define	EXT4_TIND_BLOCK			(EXT4_DIND_BLOCK + 1)
210 #define	EXT4_N_BLOCKS			(EXT4_TIND_BLOCK + 1)
211 
212 /*
213  * Inode flags
214  */
215 #define	EXT4_SECRM_FL			0x00000001 /* Secure deletion */
216 #define	EXT4_UNRM_FL			0x00000002 /* Undelete */
217 #define	EXT4_COMPR_FL			0x00000004 /* Compress file */
218 #define EXT4_SYNC_FL			0x00000008 /* Synchronous updates */
219 #define EXT4_IMMUTABLE_FL		0x00000010 /* Immutable file */
220 #define EXT4_APPEND_FL			0x00000020 /* writes to file may only append */
221 #define EXT4_NODUMP_FL			0x00000040 /* do not dump file */
222 #define EXT4_NOATIME_FL			0x00000080 /* do not update atime */
223 /* Reserved for compression usage... */
224 #define EXT4_DIRTY_FL			0x00000100
225 #define EXT4_COMPRBLK_FL		0x00000200 /* One or more compressed clusters */
226 #define EXT4_NOCOMPR_FL			0x00000400 /* Don't compress */
227 #define EXT4_ECOMPR_FL			0x00000800 /* Compression error */
228 /* End compression flags --- maybe not all used */
229 #define EXT4_INDEX_FL			0x00001000 /* hash-indexed directory */
230 #define EXT4_IMAGIC_FL			0x00002000 /* AFS directory */
231 #define EXT4_JOURNAL_DATA_FL		0x00004000 /* file data should be journaled */
232 #define EXT4_NOTAIL_FL			0x00008000 /* file tail should not be merged */
233 #define EXT4_DIRSYNC_FL			0x00010000 /* dirsync behaviour (directories only) */
234 #define EXT4_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
235 #define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
236 #define EXT4_EXTENTS_FL			0x00080000 /* Inode uses extents */
237 #define EXT4_EXT_MIGRATE		0x00100000 /* Inode is migrating */
238 #define EXT4_RESERVED_FL		0x80000000 /* reserved for ext4 lib */
239 
240 #define EXT4_FL_USER_VISIBLE		0x000BDFFF /* User visible flags */
241 #define EXT4_FL_USER_MODIFIABLE		0x000B80FF /* User modifiable flags */
242 
243 /* Flags that should be inherited by new inodes from their parent. */
244 #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
245 			   EXT4_SYNC_FL | EXT4_IMMUTABLE_FL | EXT4_APPEND_FL |\
246 			   EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
247 			   EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
248 			   EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL)
249 
250 /* Flags that are appropriate for regular files (all but dir-specific ones). */
251 #define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL))
252 
253 /* Flags that are appropriate for non-directories/regular files. */
254 #define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
255 
256 /* Mask out flags that are inappropriate for the given type of inode. */
257 static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
258 {
259 	if (S_ISDIR(mode))
260 		return flags;
261 	else if (S_ISREG(mode))
262 		return flags & EXT4_REG_FLMASK;
263 	else
264 		return flags & EXT4_OTHER_FLMASK;
265 }
266 
267 /*
268  * Inode dynamic state flags
269  */
270 #define EXT4_STATE_JDATA		0x00000001 /* journaled data exists */
271 #define EXT4_STATE_NEW			0x00000002 /* inode is newly created */
272 #define EXT4_STATE_XATTR		0x00000004 /* has in-inode xattrs */
273 #define EXT4_STATE_NO_EXPAND		0x00000008 /* No space for expansion */
274 #define EXT4_STATE_DA_ALLOC_CLOSE	0x00000010 /* Alloc DA blks on close */
275 
276 /* Used to pass group descriptor data when online resize is done */
277 struct ext4_new_group_input {
278 	__u32 group;		/* Group number for this data */
279 	__u64 block_bitmap;	/* Absolute block number of block bitmap */
280 	__u64 inode_bitmap;	/* Absolute block number of inode bitmap */
281 	__u64 inode_table;	/* Absolute block number of inode table start */
282 	__u32 blocks_count;	/* Total number of blocks in this group */
283 	__u16 reserved_blocks;	/* Number of reserved blocks in this group */
284 	__u16 unused;
285 };
286 
287 /* The struct ext4_new_group_input in kernel space, with free_blocks_count */
288 struct ext4_new_group_data {
289 	__u32 group;
290 	__u64 block_bitmap;
291 	__u64 inode_bitmap;
292 	__u64 inode_table;
293 	__u32 blocks_count;
294 	__u16 reserved_blocks;
295 	__u16 unused;
296 	__u32 free_blocks_count;
297 };
298 
299 /*
300  * Following is used by preallocation code to tell get_blocks() that we
301  * want uninitialzed extents.
302  */
303 #define EXT4_CREATE_UNINITIALIZED_EXT		2
304 
305 /*
306  * ioctl commands
307  */
308 #define	EXT4_IOC_GETFLAGS		FS_IOC_GETFLAGS
309 #define	EXT4_IOC_SETFLAGS		FS_IOC_SETFLAGS
310 #define	EXT4_IOC_GETVERSION		_IOR('f', 3, long)
311 #define	EXT4_IOC_SETVERSION		_IOW('f', 4, long)
312 #define	EXT4_IOC_GETVERSION_OLD		FS_IOC_GETVERSION
313 #define	EXT4_IOC_SETVERSION_OLD		FS_IOC_SETVERSION
314 #ifdef CONFIG_JBD2_DEBUG
315 #define EXT4_IOC_WAIT_FOR_READONLY	_IOR('f', 99, long)
316 #endif
317 #define EXT4_IOC_GETRSVSZ		_IOR('f', 5, long)
318 #define EXT4_IOC_SETRSVSZ		_IOW('f', 6, long)
319 #define EXT4_IOC_GROUP_EXTEND		_IOW('f', 7, unsigned long)
320 #define EXT4_IOC_GROUP_ADD		_IOW('f', 8, struct ext4_new_group_input)
321 #define EXT4_IOC_MIGRATE		_IO('f', 9)
322  /* note ioctl 10 reserved for an early version of the FIEMAP ioctl */
323  /* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
324 #define EXT4_IOC_ALLOC_DA_BLKS		_IO('f', 12)
325 
326 /*
327  * ioctl commands in 32 bit emulation
328  */
329 #define EXT4_IOC32_GETFLAGS		FS_IOC32_GETFLAGS
330 #define EXT4_IOC32_SETFLAGS		FS_IOC32_SETFLAGS
331 #define EXT4_IOC32_GETVERSION		_IOR('f', 3, int)
332 #define EXT4_IOC32_SETVERSION		_IOW('f', 4, int)
333 #define EXT4_IOC32_GETRSVSZ		_IOR('f', 5, int)
334 #define EXT4_IOC32_SETRSVSZ		_IOW('f', 6, int)
335 #define EXT4_IOC32_GROUP_EXTEND		_IOW('f', 7, unsigned int)
336 #ifdef CONFIG_JBD2_DEBUG
337 #define EXT4_IOC32_WAIT_FOR_READONLY	_IOR('f', 99, int)
338 #endif
339 #define EXT4_IOC32_GETVERSION_OLD	FS_IOC32_GETVERSION
340 #define EXT4_IOC32_SETVERSION_OLD	FS_IOC32_SETVERSION
341 
342 
343 /*
344  *  Mount options
345  */
346 struct ext4_mount_options {
347 	unsigned long s_mount_opt;
348 	uid_t s_resuid;
349 	gid_t s_resgid;
350 	unsigned long s_commit_interval;
351 	u32 s_min_batch_time, s_max_batch_time;
352 #ifdef CONFIG_QUOTA
353 	int s_jquota_fmt;
354 	char *s_qf_names[MAXQUOTAS];
355 #endif
356 };
357 
358 /*
359  * Structure of an inode on the disk
360  */
361 struct ext4_inode {
362 	__le16	i_mode;		/* File mode */
363 	__le16	i_uid;		/* Low 16 bits of Owner Uid */
364 	__le32	i_size_lo;	/* Size in bytes */
365 	__le32	i_atime;	/* Access time */
366 	__le32	i_ctime;	/* Inode Change time */
367 	__le32	i_mtime;	/* Modification time */
368 	__le32	i_dtime;	/* Deletion Time */
369 	__le16	i_gid;		/* Low 16 bits of Group Id */
370 	__le16	i_links_count;	/* Links count */
371 	__le32	i_blocks_lo;	/* Blocks count */
372 	__le32	i_flags;	/* File flags */
373 	union {
374 		struct {
375 			__le32  l_i_version;
376 		} linux1;
377 		struct {
378 			__u32  h_i_translator;
379 		} hurd1;
380 		struct {
381 			__u32  m_i_reserved1;
382 		} masix1;
383 	} osd1;				/* OS dependent 1 */
384 	__le32	i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
385 	__le32	i_generation;	/* File version (for NFS) */
386 	__le32	i_file_acl_lo;	/* File ACL */
387 	__le32	i_size_high;
388 	__le32	i_obso_faddr;	/* Obsoleted fragment address */
389 	union {
390 		struct {
391 			__le16	l_i_blocks_high; /* were l_i_reserved1 */
392 			__le16	l_i_file_acl_high;
393 			__le16	l_i_uid_high;	/* these 2 fields */
394 			__le16	l_i_gid_high;	/* were reserved2[0] */
395 			__u32	l_i_reserved2;
396 		} linux2;
397 		struct {
398 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
399 			__u16	h_i_mode_high;
400 			__u16	h_i_uid_high;
401 			__u16	h_i_gid_high;
402 			__u32	h_i_author;
403 		} hurd2;
404 		struct {
405 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
406 			__le16	m_i_file_acl_high;
407 			__u32	m_i_reserved2[2];
408 		} masix2;
409 	} osd2;				/* OS dependent 2 */
410 	__le16	i_extra_isize;
411 	__le16	i_pad1;
412 	__le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
413 	__le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
414 	__le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
415 	__le32  i_crtime;       /* File Creation time */
416 	__le32  i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
417 	__le32  i_version_hi;	/* high 32 bits for 64-bit version */
418 };
419 
420 
421 #define EXT4_EPOCH_BITS 2
422 #define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
423 #define EXT4_NSEC_MASK  (~0UL << EXT4_EPOCH_BITS)
424 
425 /*
426  * Extended fields will fit into an inode if the filesystem was formatted
427  * with large inodes (-I 256 or larger) and there are not currently any EAs
428  * consuming all of the available space. For new inodes we always reserve
429  * enough space for the kernel's known extended fields, but for inodes
430  * created with an old kernel this might not have been the case. None of
431  * the extended inode fields is critical for correct filesystem operation.
432  * This macro checks if a certain field fits in the inode. Note that
433  * inode-size = GOOD_OLD_INODE_SIZE + i_extra_isize
434  */
435 #define EXT4_FITS_IN_INODE(ext4_inode, einode, field)	\
436 	((offsetof(typeof(*ext4_inode), field) +	\
437 	  sizeof((ext4_inode)->field))			\
438 	<= (EXT4_GOOD_OLD_INODE_SIZE +			\
439 	    (einode)->i_extra_isize))			\
440 
441 static inline __le32 ext4_encode_extra_time(struct timespec *time)
442 {
443        return cpu_to_le32((sizeof(time->tv_sec) > 4 ?
444 			   time->tv_sec >> 32 : 0) |
445 			   ((time->tv_nsec << 2) & EXT4_NSEC_MASK));
446 }
447 
448 static inline void ext4_decode_extra_time(struct timespec *time, __le32 extra)
449 {
450        if (sizeof(time->tv_sec) > 4)
451 	       time->tv_sec |= (__u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK)
452 			       << 32;
453        time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> 2;
454 }
455 
456 #define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode)			       \
457 do {									       \
458 	(raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec);	       \
459 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
460 		(raw_inode)->xtime ## _extra =				       \
461 				ext4_encode_extra_time(&(inode)->xtime);       \
462 } while (0)
463 
464 #define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode)			       \
465 do {									       \
466 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
467 		(raw_inode)->xtime = cpu_to_le32((einode)->xtime.tv_sec);      \
468 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
469 		(raw_inode)->xtime ## _extra =				       \
470 				ext4_encode_extra_time(&(einode)->xtime);      \
471 } while (0)
472 
473 #define EXT4_INODE_GET_XTIME(xtime, inode, raw_inode)			       \
474 do {									       \
475 	(inode)->xtime.tv_sec = (signed)le32_to_cpu((raw_inode)->xtime);       \
476 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
477 		ext4_decode_extra_time(&(inode)->xtime,			       \
478 				       raw_inode->xtime ## _extra);	       \
479 } while (0)
480 
481 #define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode)			       \
482 do {									       \
483 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
484 		(einode)->xtime.tv_sec = 				       \
485 			(signed)le32_to_cpu((raw_inode)->xtime);	       \
486 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
487 		ext4_decode_extra_time(&(einode)->xtime,		       \
488 				       raw_inode->xtime ## _extra);	       \
489 } while (0)
490 
491 #define i_disk_version osd1.linux1.l_i_version
492 
493 #if defined(__KERNEL__) || defined(__linux__)
494 #define i_reserved1	osd1.linux1.l_i_reserved1
495 #define i_file_acl_high	osd2.linux2.l_i_file_acl_high
496 #define i_blocks_high	osd2.linux2.l_i_blocks_high
497 #define i_uid_low	i_uid
498 #define i_gid_low	i_gid
499 #define i_uid_high	osd2.linux2.l_i_uid_high
500 #define i_gid_high	osd2.linux2.l_i_gid_high
501 #define i_reserved2	osd2.linux2.l_i_reserved2
502 
503 #elif defined(__GNU__)
504 
505 #define i_translator	osd1.hurd1.h_i_translator
506 #define i_uid_high	osd2.hurd2.h_i_uid_high
507 #define i_gid_high	osd2.hurd2.h_i_gid_high
508 #define i_author	osd2.hurd2.h_i_author
509 
510 #elif defined(__masix__)
511 
512 #define i_reserved1	osd1.masix1.m_i_reserved1
513 #define i_file_acl_high	osd2.masix2.m_i_file_acl_high
514 #define i_reserved2	osd2.masix2.m_i_reserved2
515 
516 #endif /* defined(__KERNEL__) || defined(__linux__) */
517 
518 /*
519  * File system states
520  */
521 #define	EXT4_VALID_FS			0x0001	/* Unmounted cleanly */
522 #define	EXT4_ERROR_FS			0x0002	/* Errors detected */
523 #define	EXT4_ORPHAN_FS			0x0004	/* Orphans being recovered */
524 
525 /*
526  * Misc. filesystem flags
527  */
528 #define EXT2_FLAGS_SIGNED_HASH		0x0001  /* Signed dirhash in use */
529 #define EXT2_FLAGS_UNSIGNED_HASH	0x0002  /* Unsigned dirhash in use */
530 #define EXT2_FLAGS_TEST_FILESYS		0x0004	/* to test development code */
531 
532 /*
533  * Mount flags
534  */
535 #define EXT4_MOUNT_OLDALLOC		0x00002  /* Don't use the new Orlov allocator */
536 #define EXT4_MOUNT_GRPID		0x00004	/* Create files with directory's group */
537 #define EXT4_MOUNT_DEBUG		0x00008	/* Some debugging messages */
538 #define EXT4_MOUNT_ERRORS_CONT		0x00010	/* Continue on errors */
539 #define EXT4_MOUNT_ERRORS_RO		0x00020	/* Remount fs ro on errors */
540 #define EXT4_MOUNT_ERRORS_PANIC		0x00040	/* Panic on errors */
541 #define EXT4_MOUNT_MINIX_DF		0x00080	/* Mimics the Minix statfs */
542 #define EXT4_MOUNT_NOLOAD		0x00100	/* Don't use existing journal*/
543 #define EXT4_MOUNT_ABORT		0x00200	/* Fatal error detected */
544 #define EXT4_MOUNT_DATA_FLAGS		0x00C00	/* Mode for data writes: */
545 #define EXT4_MOUNT_JOURNAL_DATA		0x00400	/* Write data to journal */
546 #define EXT4_MOUNT_ORDERED_DATA		0x00800	/* Flush data before commit */
547 #define EXT4_MOUNT_WRITEBACK_DATA	0x00C00	/* No data ordering */
548 #define EXT4_MOUNT_UPDATE_JOURNAL	0x01000	/* Update the journal format */
549 #define EXT4_MOUNT_NO_UID32		0x02000  /* Disable 32-bit UIDs */
550 #define EXT4_MOUNT_XATTR_USER		0x04000	/* Extended user attributes */
551 #define EXT4_MOUNT_POSIX_ACL		0x08000	/* POSIX Access Control Lists */
552 #define EXT4_MOUNT_NO_AUTO_DA_ALLOC	0x10000	/* No auto delalloc mapping */
553 #define EXT4_MOUNT_BARRIER		0x20000 /* Use block barriers */
554 #define EXT4_MOUNT_NOBH			0x40000 /* No bufferheads */
555 #define EXT4_MOUNT_QUOTA		0x80000 /* Some quota option set */
556 #define EXT4_MOUNT_USRQUOTA		0x100000 /* "old" user quota */
557 #define EXT4_MOUNT_GRPQUOTA		0x200000 /* "old" group quota */
558 #define EXT4_MOUNT_JOURNAL_CHECKSUM	0x800000 /* Journal checksums */
559 #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT	0x1000000 /* Journal Async Commit */
560 #define EXT4_MOUNT_I_VERSION            0x2000000 /* i_version support */
561 #define EXT4_MOUNT_DELALLOC		0x8000000 /* Delalloc support */
562 #define EXT4_MOUNT_DATA_ERR_ABORT	0x10000000 /* Abort on file data write */
563 
564 /* Compatibility, for having both ext2_fs.h and ext4_fs.h included at once */
565 #ifndef _LINUX_EXT2_FS_H
566 #define clear_opt(o, opt)		o &= ~EXT4_MOUNT_##opt
567 #define set_opt(o, opt)			o |= EXT4_MOUNT_##opt
568 #define test_opt(sb, opt)		(EXT4_SB(sb)->s_mount_opt & \
569 					 EXT4_MOUNT_##opt)
570 #else
571 #define EXT2_MOUNT_NOLOAD		EXT4_MOUNT_NOLOAD
572 #define EXT2_MOUNT_ABORT		EXT4_MOUNT_ABORT
573 #define EXT2_MOUNT_DATA_FLAGS		EXT4_MOUNT_DATA_FLAGS
574 #endif
575 
576 #define ext4_set_bit			ext2_set_bit
577 #define ext4_set_bit_atomic		ext2_set_bit_atomic
578 #define ext4_clear_bit			ext2_clear_bit
579 #define ext4_clear_bit_atomic		ext2_clear_bit_atomic
580 #define ext4_test_bit			ext2_test_bit
581 #define ext4_find_first_zero_bit	ext2_find_first_zero_bit
582 #define ext4_find_next_zero_bit		ext2_find_next_zero_bit
583 #define ext4_find_next_bit		ext2_find_next_bit
584 
585 /*
586  * Maximal mount counts between two filesystem checks
587  */
588 #define EXT4_DFL_MAX_MNT_COUNT		20	/* Allow 20 mounts */
589 #define EXT4_DFL_CHECKINTERVAL		0	/* Don't use interval check */
590 
591 /*
592  * Behaviour when detecting errors
593  */
594 #define EXT4_ERRORS_CONTINUE		1	/* Continue execution */
595 #define EXT4_ERRORS_RO			2	/* Remount fs read-only */
596 #define EXT4_ERRORS_PANIC		3	/* Panic */
597 #define EXT4_ERRORS_DEFAULT		EXT4_ERRORS_CONTINUE
598 
599 /*
600  * Structure of the super block
601  */
602 struct ext4_super_block {
603 /*00*/	__le32	s_inodes_count;		/* Inodes count */
604 	__le32	s_blocks_count_lo;	/* Blocks count */
605 	__le32	s_r_blocks_count_lo;	/* Reserved blocks count */
606 	__le32	s_free_blocks_count_lo;	/* Free blocks count */
607 /*10*/	__le32	s_free_inodes_count;	/* Free inodes count */
608 	__le32	s_first_data_block;	/* First Data Block */
609 	__le32	s_log_block_size;	/* Block size */
610 	__le32	s_obso_log_frag_size;	/* Obsoleted fragment size */
611 /*20*/	__le32	s_blocks_per_group;	/* # Blocks per group */
612 	__le32	s_obso_frags_per_group;	/* Obsoleted fragments per group */
613 	__le32	s_inodes_per_group;	/* # Inodes per group */
614 	__le32	s_mtime;		/* Mount time */
615 /*30*/	__le32	s_wtime;		/* Write time */
616 	__le16	s_mnt_count;		/* Mount count */
617 	__le16	s_max_mnt_count;	/* Maximal mount count */
618 	__le16	s_magic;		/* Magic signature */
619 	__le16	s_state;		/* File system state */
620 	__le16	s_errors;		/* Behaviour when detecting errors */
621 	__le16	s_minor_rev_level;	/* minor revision level */
622 /*40*/	__le32	s_lastcheck;		/* time of last check */
623 	__le32	s_checkinterval;	/* max. time between checks */
624 	__le32	s_creator_os;		/* OS */
625 	__le32	s_rev_level;		/* Revision level */
626 /*50*/	__le16	s_def_resuid;		/* Default uid for reserved blocks */
627 	__le16	s_def_resgid;		/* Default gid for reserved blocks */
628 	/*
629 	 * These fields are for EXT4_DYNAMIC_REV superblocks only.
630 	 *
631 	 * Note: the difference between the compatible feature set and
632 	 * the incompatible feature set is that if there is a bit set
633 	 * in the incompatible feature set that the kernel doesn't
634 	 * know about, it should refuse to mount the filesystem.
635 	 *
636 	 * e2fsck's requirements are more strict; if it doesn't know
637 	 * about a feature in either the compatible or incompatible
638 	 * feature set, it must abort and not try to meddle with
639 	 * things it doesn't understand...
640 	 */
641 	__le32	s_first_ino;		/* First non-reserved inode */
642 	__le16  s_inode_size;		/* size of inode structure */
643 	__le16	s_block_group_nr;	/* block group # of this superblock */
644 	__le32	s_feature_compat;	/* compatible feature set */
645 /*60*/	__le32	s_feature_incompat;	/* incompatible feature set */
646 	__le32	s_feature_ro_compat;	/* readonly-compatible feature set */
647 /*68*/	__u8	s_uuid[16];		/* 128-bit uuid for volume */
648 /*78*/	char	s_volume_name[16];	/* volume name */
649 /*88*/	char	s_last_mounted[64];	/* directory where last mounted */
650 /*C8*/	__le32	s_algorithm_usage_bitmap; /* For compression */
651 	/*
652 	 * Performance hints.  Directory preallocation should only
653 	 * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
654 	 */
655 	__u8	s_prealloc_blocks;	/* Nr of blocks to try to preallocate*/
656 	__u8	s_prealloc_dir_blocks;	/* Nr to preallocate for dirs */
657 	__le16	s_reserved_gdt_blocks;	/* Per group desc for online growth */
658 	/*
659 	 * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
660 	 */
661 /*D0*/	__u8	s_journal_uuid[16];	/* uuid of journal superblock */
662 /*E0*/	__le32	s_journal_inum;		/* inode number of journal file */
663 	__le32	s_journal_dev;		/* device number of journal file */
664 	__le32	s_last_orphan;		/* start of list of inodes to delete */
665 	__le32	s_hash_seed[4];		/* HTREE hash seed */
666 	__u8	s_def_hash_version;	/* Default hash version to use */
667 	__u8	s_reserved_char_pad;
668 	__le16  s_desc_size;		/* size of group descriptor */
669 /*100*/	__le32	s_default_mount_opts;
670 	__le32	s_first_meta_bg;	/* First metablock block group */
671 	__le32	s_mkfs_time;		/* When the filesystem was created */
672 	__le32	s_jnl_blocks[17];	/* Backup of the journal inode */
673 	/* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
674 /*150*/	__le32	s_blocks_count_hi;	/* Blocks count */
675 	__le32	s_r_blocks_count_hi;	/* Reserved blocks count */
676 	__le32	s_free_blocks_count_hi;	/* Free blocks count */
677 	__le16	s_min_extra_isize;	/* All inodes have at least # bytes */
678 	__le16	s_want_extra_isize; 	/* New inodes should reserve # bytes */
679 	__le32	s_flags;		/* Miscellaneous flags */
680 	__le16  s_raid_stride;		/* RAID stride */
681 	__le16  s_mmp_interval;         /* # seconds to wait in MMP checking */
682 	__le64  s_mmp_block;            /* Block for multi-mount protection */
683 	__le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
684 	__u8	s_log_groups_per_flex;  /* FLEX_BG group size */
685 	__u8	s_reserved_char_pad2;
686 	__le16  s_reserved_pad;
687 	__le64	s_kbytes_written;	/* nr of lifetime kilobytes written */
688 	__u32   s_reserved[160];        /* Padding to the end of the block */
689 };
690 
691 #ifdef __KERNEL__
692 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
693 {
694 	return sb->s_fs_info;
695 }
696 static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
697 {
698 	return container_of(inode, struct ext4_inode_info, vfs_inode);
699 }
700 
701 static inline struct timespec ext4_current_time(struct inode *inode)
702 {
703 	return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
704 		current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
705 }
706 
707 
708 static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
709 {
710 	return ino == EXT4_ROOT_INO ||
711 		ino == EXT4_JOURNAL_INO ||
712 		ino == EXT4_RESIZE_INO ||
713 		(ino >= EXT4_FIRST_INO(sb) &&
714 		 ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
715 }
716 #else
717 /* Assume that user mode programs are passing in an ext4fs superblock, not
718  * a kernel struct super_block.  This will allow us to call the feature-test
719  * macros from user land. */
720 #define EXT4_SB(sb)	(sb)
721 #endif
722 
723 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
724 
725 /*
726  * Codes for operating systems
727  */
728 #define EXT4_OS_LINUX		0
729 #define EXT4_OS_HURD		1
730 #define EXT4_OS_MASIX		2
731 #define EXT4_OS_FREEBSD		3
732 #define EXT4_OS_LITES		4
733 
734 /*
735  * Revision levels
736  */
737 #define EXT4_GOOD_OLD_REV	0	/* The good old (original) format */
738 #define EXT4_DYNAMIC_REV	1	/* V2 format w/ dynamic inode sizes */
739 
740 #define EXT4_CURRENT_REV	EXT4_GOOD_OLD_REV
741 #define EXT4_MAX_SUPP_REV	EXT4_DYNAMIC_REV
742 
743 #define EXT4_GOOD_OLD_INODE_SIZE 128
744 
745 /*
746  * Feature set definitions
747  */
748 
749 #define EXT4_HAS_COMPAT_FEATURE(sb,mask)			\
750 	((EXT4_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask)) != 0)
751 #define EXT4_HAS_RO_COMPAT_FEATURE(sb,mask)			\
752 	((EXT4_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask)) != 0)
753 #define EXT4_HAS_INCOMPAT_FEATURE(sb,mask)			\
754 	((EXT4_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask)) != 0)
755 #define EXT4_SET_COMPAT_FEATURE(sb,mask)			\
756 	EXT4_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
757 #define EXT4_SET_RO_COMPAT_FEATURE(sb,mask)			\
758 	EXT4_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
759 #define EXT4_SET_INCOMPAT_FEATURE(sb,mask)			\
760 	EXT4_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
761 #define EXT4_CLEAR_COMPAT_FEATURE(sb,mask)			\
762 	EXT4_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
763 #define EXT4_CLEAR_RO_COMPAT_FEATURE(sb,mask)			\
764 	EXT4_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
765 #define EXT4_CLEAR_INCOMPAT_FEATURE(sb,mask)			\
766 	EXT4_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
767 
768 #define EXT4_FEATURE_COMPAT_DIR_PREALLOC	0x0001
769 #define EXT4_FEATURE_COMPAT_IMAGIC_INODES	0x0002
770 #define EXT4_FEATURE_COMPAT_HAS_JOURNAL		0x0004
771 #define EXT4_FEATURE_COMPAT_EXT_ATTR		0x0008
772 #define EXT4_FEATURE_COMPAT_RESIZE_INODE	0x0010
773 #define EXT4_FEATURE_COMPAT_DIR_INDEX		0x0020
774 
775 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
776 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
777 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR	0x0004
778 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
779 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM		0x0010
780 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK	0x0020
781 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE	0x0040
782 
783 #define EXT4_FEATURE_INCOMPAT_COMPRESSION	0x0001
784 #define EXT4_FEATURE_INCOMPAT_FILETYPE		0x0002
785 #define EXT4_FEATURE_INCOMPAT_RECOVER		0x0004 /* Needs recovery */
786 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008 /* Journal device */
787 #define EXT4_FEATURE_INCOMPAT_META_BG		0x0010
788 #define EXT4_FEATURE_INCOMPAT_EXTENTS		0x0040 /* extents support */
789 #define EXT4_FEATURE_INCOMPAT_64BIT		0x0080
790 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
791 #define EXT4_FEATURE_INCOMPAT_FLEX_BG		0x0200
792 
793 #define EXT4_FEATURE_COMPAT_SUPP	EXT2_FEATURE_COMPAT_EXT_ATTR
794 #define EXT4_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
795 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
796 					 EXT4_FEATURE_INCOMPAT_META_BG| \
797 					 EXT4_FEATURE_INCOMPAT_EXTENTS| \
798 					 EXT4_FEATURE_INCOMPAT_64BIT| \
799 					 EXT4_FEATURE_INCOMPAT_FLEX_BG)
800 #define EXT4_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
801 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
802 					 EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
803 					 EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
804 					 EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
805 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
806 					 EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
807 
808 /*
809  * Default values for user and/or group using reserved blocks
810  */
811 #define	EXT4_DEF_RESUID		0
812 #define	EXT4_DEF_RESGID		0
813 
814 #define EXT4_DEF_INODE_READAHEAD_BLKS	32
815 
816 /*
817  * Default mount options
818  */
819 #define EXT4_DEFM_DEBUG		0x0001
820 #define EXT4_DEFM_BSDGROUPS	0x0002
821 #define EXT4_DEFM_XATTR_USER	0x0004
822 #define EXT4_DEFM_ACL		0x0008
823 #define EXT4_DEFM_UID16		0x0010
824 #define EXT4_DEFM_JMODE		0x0060
825 #define EXT4_DEFM_JMODE_DATA	0x0020
826 #define EXT4_DEFM_JMODE_ORDERED	0x0040
827 #define EXT4_DEFM_JMODE_WBACK	0x0060
828 
829 /*
830  * Default journal batch times
831  */
832 #define EXT4_DEF_MIN_BATCH_TIME	0
833 #define EXT4_DEF_MAX_BATCH_TIME	15000 /* 15ms */
834 
835 /*
836  * Minimum number of groups in a flexgroup before we separate out
837  * directories into the first block group of a flexgroup
838  */
839 #define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME	4
840 
841 /*
842  * Structure of a directory entry
843  */
844 #define EXT4_NAME_LEN 255
845 
846 struct ext4_dir_entry {
847 	__le32	inode;			/* Inode number */
848 	__le16	rec_len;		/* Directory entry length */
849 	__le16	name_len;		/* Name length */
850 	char	name[EXT4_NAME_LEN];	/* File name */
851 };
852 
853 /*
854  * The new version of the directory entry.  Since EXT4 structures are
855  * stored in intel byte order, and the name_len field could never be
856  * bigger than 255 chars, it's safe to reclaim the extra byte for the
857  * file_type field.
858  */
859 struct ext4_dir_entry_2 {
860 	__le32	inode;			/* Inode number */
861 	__le16	rec_len;		/* Directory entry length */
862 	__u8	name_len;		/* Name length */
863 	__u8	file_type;
864 	char	name[EXT4_NAME_LEN];	/* File name */
865 };
866 
867 /*
868  * Ext4 directory file types.  Only the low 3 bits are used.  The
869  * other bits are reserved for now.
870  */
871 #define EXT4_FT_UNKNOWN		0
872 #define EXT4_FT_REG_FILE	1
873 #define EXT4_FT_DIR		2
874 #define EXT4_FT_CHRDEV		3
875 #define EXT4_FT_BLKDEV		4
876 #define EXT4_FT_FIFO		5
877 #define EXT4_FT_SOCK		6
878 #define EXT4_FT_SYMLINK		7
879 
880 #define EXT4_FT_MAX		8
881 
882 /*
883  * EXT4_DIR_PAD defines the directory entries boundaries
884  *
885  * NOTE: It must be a multiple of 4
886  */
887 #define EXT4_DIR_PAD			4
888 #define EXT4_DIR_ROUND			(EXT4_DIR_PAD - 1)
889 #define EXT4_DIR_REC_LEN(name_len)	(((name_len) + 8 + EXT4_DIR_ROUND) & \
890 					 ~EXT4_DIR_ROUND)
891 #define EXT4_MAX_REC_LEN		((1<<16)-1)
892 
893 /*
894  * Hash Tree Directory indexing
895  * (c) Daniel Phillips, 2001
896  */
897 
898 #define is_dx(dir) (EXT4_HAS_COMPAT_FEATURE(dir->i_sb, \
899 				      EXT4_FEATURE_COMPAT_DIR_INDEX) && \
900 		      (EXT4_I(dir)->i_flags & EXT4_INDEX_FL))
901 #define EXT4_DIR_LINK_MAX(dir) (!is_dx(dir) && (dir)->i_nlink >= EXT4_LINK_MAX)
902 #define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
903 
904 /* Legal values for the dx_root hash_version field: */
905 
906 #define DX_HASH_LEGACY		0
907 #define DX_HASH_HALF_MD4	1
908 #define DX_HASH_TEA		2
909 #define DX_HASH_LEGACY_UNSIGNED	3
910 #define DX_HASH_HALF_MD4_UNSIGNED	4
911 #define DX_HASH_TEA_UNSIGNED		5
912 
913 #ifdef __KERNEL__
914 
915 /* hash info structure used by the directory hash */
916 struct dx_hash_info
917 {
918 	u32		hash;
919 	u32		minor_hash;
920 	int		hash_version;
921 	u32		*seed;
922 };
923 
924 #define EXT4_HTREE_EOF	0x7fffffff
925 
926 /*
927  * Control parameters used by ext4_htree_next_block
928  */
929 #define HASH_NB_ALWAYS		1
930 
931 
932 /*
933  * Describe an inode's exact location on disk and in memory
934  */
935 struct ext4_iloc
936 {
937 	struct buffer_head *bh;
938 	unsigned long offset;
939 	ext4_group_t block_group;
940 };
941 
942 static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
943 {
944 	return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
945 }
946 
947 /*
948  * This structure is stuffed into the struct file's private_data field
949  * for directories.  It is where we put information so that we can do
950  * readdir operations in hash tree order.
951  */
952 struct dir_private_info {
953 	struct rb_root	root;
954 	struct rb_node	*curr_node;
955 	struct fname	*extra_fname;
956 	loff_t		last_pos;
957 	__u32		curr_hash;
958 	__u32		curr_minor_hash;
959 	__u32		next_hash;
960 };
961 
962 /* calculate the first block number of the group */
963 static inline ext4_fsblk_t
964 ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
965 {
966 	return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
967 		le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
968 }
969 
970 /*
971  * Special error return code only used by dx_probe() and its callers.
972  */
973 #define ERR_BAD_DX_DIR	-75000
974 
975 void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,
976 			ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp);
977 
978 extern struct proc_dir_entry *ext4_proc_root;
979 
980 /*
981  * Function prototypes
982  */
983 
984 /*
985  * Ok, these declarations are also in <linux/kernel.h> but none of the
986  * ext4 source programs needs to include it so they are duplicated here.
987  */
988 # define NORET_TYPE	/**/
989 # define ATTRIB_NORET	__attribute__((noreturn))
990 # define NORET_AND	noreturn,
991 
992 /* bitmap.c */
993 extern unsigned int ext4_count_free(struct buffer_head *, unsigned);
994 
995 /* balloc.c */
996 extern unsigned int ext4_block_group(struct super_block *sb,
997 			ext4_fsblk_t blocknr);
998 extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
999 			ext4_fsblk_t blocknr);
1000 extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
1001 extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
1002 			ext4_group_t group);
1003 extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
1004 			ext4_fsblk_t goal, unsigned long *count, int *errp);
1005 extern int ext4_claim_free_blocks(struct ext4_sb_info *sbi, s64 nblocks);
1006 extern int ext4_has_free_blocks(struct ext4_sb_info *sbi, s64 nblocks);
1007 extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
1008 			ext4_fsblk_t block, unsigned long count, int metadata);
1009 extern void ext4_add_groupblocks(handle_t *handle, struct super_block *sb,
1010 				ext4_fsblk_t block, unsigned long count);
1011 extern ext4_fsblk_t ext4_count_free_blocks(struct super_block *);
1012 extern void ext4_check_blocks_bitmap(struct super_block *);
1013 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
1014 						    ext4_group_t block_group,
1015 						    struct buffer_head ** bh);
1016 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
1017 
1018 /* dir.c */
1019 extern int ext4_check_dir_entry(const char *, struct inode *,
1020 				struct ext4_dir_entry_2 *,
1021 				struct buffer_head *, unsigned int);
1022 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
1023 				    __u32 minor_hash,
1024 				    struct ext4_dir_entry_2 *dirent);
1025 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
1026 
1027 /* fsync.c */
1028 extern int ext4_sync_file(struct file *, struct dentry *, int);
1029 
1030 /* hash.c */
1031 extern int ext4fs_dirhash(const char *name, int len, struct
1032 			  dx_hash_info *hinfo);
1033 
1034 /* ialloc.c */
1035 extern struct inode * ext4_new_inode(handle_t *, struct inode *, int);
1036 extern void ext4_free_inode(handle_t *, struct inode *);
1037 extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
1038 extern unsigned long ext4_count_free_inodes(struct super_block *);
1039 extern unsigned long ext4_count_dirs(struct super_block *);
1040 extern void ext4_check_inodes_bitmap(struct super_block *);
1041 
1042 /* mballoc.c */
1043 extern long ext4_mb_stats;
1044 extern long ext4_mb_max_to_scan;
1045 extern int ext4_mb_init(struct super_block *, int);
1046 extern int ext4_mb_release(struct super_block *);
1047 extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
1048 				struct ext4_allocation_request *, int *);
1049 extern int ext4_mb_reserve_blocks(struct super_block *, int);
1050 extern void ext4_discard_preallocations(struct inode *);
1051 extern int __init init_ext4_mballoc(void);
1052 extern void exit_ext4_mballoc(void);
1053 extern void ext4_mb_free_blocks(handle_t *, struct inode *,
1054 		unsigned long, unsigned long, int, unsigned long *);
1055 extern int ext4_mb_add_groupinfo(struct super_block *sb,
1056 		ext4_group_t i, struct ext4_group_desc *desc);
1057 extern void ext4_mb_update_group_info(struct ext4_group_info *grp,
1058 		ext4_grpblk_t add);
1059 extern int ext4_mb_get_buddy_cache_lock(struct super_block *, ext4_group_t);
1060 extern void ext4_mb_put_buddy_cache_lock(struct super_block *,
1061 						ext4_group_t, int);
1062 /* inode.c */
1063 int ext4_forget(handle_t *handle, int is_metadata, struct inode *inode,
1064 		struct buffer_head *bh, ext4_fsblk_t blocknr);
1065 struct buffer_head *ext4_getblk(handle_t *, struct inode *,
1066 						ext4_lblk_t, int, int *);
1067 struct buffer_head *ext4_bread(handle_t *, struct inode *,
1068 						ext4_lblk_t, int, int *);
1069 int ext4_get_block(struct inode *inode, sector_t iblock,
1070 				struct buffer_head *bh_result, int create);
1071 
1072 extern struct inode *ext4_iget(struct super_block *, unsigned long);
1073 extern int  ext4_write_inode(struct inode *, int);
1074 extern int  ext4_setattr(struct dentry *, struct iattr *);
1075 extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
1076 				struct kstat *stat);
1077 extern void ext4_delete_inode(struct inode *);
1078 extern int  ext4_sync_inode(handle_t *, struct inode *);
1079 extern void ext4_dirty_inode(struct inode *);
1080 extern int ext4_change_inode_journal_flag(struct inode *, int);
1081 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
1082 extern int ext4_can_truncate(struct inode *inode);
1083 extern void ext4_truncate(struct inode *);
1084 extern void ext4_set_inode_flags(struct inode *);
1085 extern void ext4_get_inode_flags(struct ext4_inode_info *);
1086 extern int ext4_alloc_da_blocks(struct inode *inode);
1087 extern void ext4_set_aops(struct inode *inode);
1088 extern int ext4_writepage_trans_blocks(struct inode *);
1089 extern int ext4_meta_trans_blocks(struct inode *, int nrblocks, int idxblocks);
1090 extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
1091 extern int ext4_block_truncate_page(handle_t *handle,
1092 		struct address_space *mapping, loff_t from);
1093 extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
1094 extern qsize_t ext4_get_reserved_space(struct inode *inode);
1095 
1096 /* ioctl.c */
1097 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
1098 extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
1099 
1100 /* migrate.c */
1101 extern int ext4_ext_migrate(struct inode *);
1102 
1103 /* namei.c */
1104 extern unsigned int ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize);
1105 extern __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize);
1106 extern int ext4_orphan_add(handle_t *, struct inode *);
1107 extern int ext4_orphan_del(handle_t *, struct inode *);
1108 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1109 				__u32 start_minor_hash, __u32 *next_hash);
1110 
1111 /* resize.c */
1112 extern int ext4_group_add(struct super_block *sb,
1113 				struct ext4_new_group_data *input);
1114 extern int ext4_group_extend(struct super_block *sb,
1115 				struct ext4_super_block *es,
1116 				ext4_fsblk_t n_blocks_count);
1117 
1118 /* super.c */
1119 extern void ext4_error(struct super_block *, const char *, const char *, ...)
1120 	__attribute__ ((format (printf, 3, 4)));
1121 extern void __ext4_std_error(struct super_block *, const char *, int);
1122 extern void ext4_abort(struct super_block *, const char *, const char *, ...)
1123 	__attribute__ ((format (printf, 3, 4)));
1124 extern void ext4_warning(struct super_block *, const char *, const char *, ...)
1125 	__attribute__ ((format (printf, 3, 4)));
1126 extern void ext4_grp_locked_error(struct super_block *, ext4_group_t,
1127 				const char *, const char *, ...)
1128 	__attribute__ ((format (printf, 4, 5)));
1129 extern void ext4_update_dynamic_rev(struct super_block *sb);
1130 extern int ext4_update_compat_feature(handle_t *handle, struct super_block *sb,
1131 					__u32 compat);
1132 extern int ext4_update_rocompat_feature(handle_t *handle,
1133 					struct super_block *sb,	__u32 rocompat);
1134 extern int ext4_update_incompat_feature(handle_t *handle,
1135 					struct super_block *sb,	__u32 incompat);
1136 extern ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
1137 				      struct ext4_group_desc *bg);
1138 extern ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
1139 				      struct ext4_group_desc *bg);
1140 extern ext4_fsblk_t ext4_inode_table(struct super_block *sb,
1141 				     struct ext4_group_desc *bg);
1142 extern __u32 ext4_free_blks_count(struct super_block *sb,
1143 				struct ext4_group_desc *bg);
1144 extern __u32 ext4_free_inodes_count(struct super_block *sb,
1145 				 struct ext4_group_desc *bg);
1146 extern __u32 ext4_used_dirs_count(struct super_block *sb,
1147 				struct ext4_group_desc *bg);
1148 extern __u32 ext4_itable_unused_count(struct super_block *sb,
1149 				   struct ext4_group_desc *bg);
1150 extern void ext4_block_bitmap_set(struct super_block *sb,
1151 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
1152 extern void ext4_inode_bitmap_set(struct super_block *sb,
1153 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
1154 extern void ext4_inode_table_set(struct super_block *sb,
1155 				 struct ext4_group_desc *bg, ext4_fsblk_t blk);
1156 extern void ext4_free_blks_set(struct super_block *sb,
1157 			       struct ext4_group_desc *bg, __u32 count);
1158 extern void ext4_free_inodes_set(struct super_block *sb,
1159 				struct ext4_group_desc *bg, __u32 count);
1160 extern void ext4_used_dirs_set(struct super_block *sb,
1161 				struct ext4_group_desc *bg, __u32 count);
1162 extern void ext4_itable_unused_set(struct super_block *sb,
1163 				   struct ext4_group_desc *bg, __u32 count);
1164 
1165 static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
1166 {
1167 	return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |
1168 		le32_to_cpu(es->s_blocks_count_lo);
1169 }
1170 
1171 static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
1172 {
1173 	return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |
1174 		le32_to_cpu(es->s_r_blocks_count_lo);
1175 }
1176 
1177 static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
1178 {
1179 	return ((ext4_fsblk_t)le32_to_cpu(es->s_free_blocks_count_hi) << 32) |
1180 		le32_to_cpu(es->s_free_blocks_count_lo);
1181 }
1182 
1183 static inline void ext4_blocks_count_set(struct ext4_super_block *es,
1184 					 ext4_fsblk_t blk)
1185 {
1186 	es->s_blocks_count_lo = cpu_to_le32((u32)blk);
1187 	es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
1188 }
1189 
1190 static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
1191 					      ext4_fsblk_t blk)
1192 {
1193 	es->s_free_blocks_count_lo = cpu_to_le32((u32)blk);
1194 	es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
1195 }
1196 
1197 static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
1198 					   ext4_fsblk_t blk)
1199 {
1200 	es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
1201 	es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
1202 }
1203 
1204 static inline loff_t ext4_isize(struct ext4_inode *raw_inode)
1205 {
1206 	if (S_ISREG(le16_to_cpu(raw_inode->i_mode)))
1207 		return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
1208 			le32_to_cpu(raw_inode->i_size_lo);
1209 	else
1210 		return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
1211 }
1212 
1213 static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
1214 {
1215 	raw_inode->i_size_lo = cpu_to_le32(i_size);
1216 	raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
1217 }
1218 
1219 static inline
1220 struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
1221 					    ext4_group_t group)
1222 {
1223 	 struct ext4_group_info ***grp_info;
1224 	 long indexv, indexh;
1225 	 grp_info = EXT4_SB(sb)->s_group_info;
1226 	 indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
1227 	 indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
1228 	 return grp_info[indexv][indexh];
1229 }
1230 
1231 
1232 static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
1233 					     ext4_group_t block_group)
1234 {
1235 	return block_group >> sbi->s_log_groups_per_flex;
1236 }
1237 
1238 static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
1239 {
1240 	return 1 << sbi->s_log_groups_per_flex;
1241 }
1242 
1243 #define ext4_std_error(sb, errno)				\
1244 do {								\
1245 	if ((errno))						\
1246 		__ext4_std_error((sb), __func__, (errno));	\
1247 } while (0)
1248 
1249 #ifdef CONFIG_SMP
1250 /* Each CPU can accumulate percpu_counter_batch blocks in their local
1251  * counters. So we need to make sure we have free blocks more
1252  * than percpu_counter_batch  * nr_cpu_ids. Also add a window of 4 times.
1253  */
1254 #define EXT4_FREEBLOCKS_WATERMARK (4 * (percpu_counter_batch * nr_cpu_ids))
1255 #else
1256 #define EXT4_FREEBLOCKS_WATERMARK 0
1257 #endif
1258 
1259 static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
1260 {
1261 	/*
1262 	 * XXX: replace with spinlock if seen contended -bzzz
1263 	 */
1264 	down_write(&EXT4_I(inode)->i_data_sem);
1265 	if (newsize > EXT4_I(inode)->i_disksize)
1266 		EXT4_I(inode)->i_disksize = newsize;
1267 	up_write(&EXT4_I(inode)->i_data_sem);
1268 	return ;
1269 }
1270 
1271 struct ext4_group_info {
1272 	unsigned long   bb_state;
1273 	struct rb_root  bb_free_root;
1274 	unsigned short  bb_first_free;
1275 	unsigned short  bb_free;
1276 	unsigned short  bb_fragments;
1277 	struct          list_head bb_prealloc_list;
1278 #ifdef DOUBLE_CHECK
1279 	void            *bb_bitmap;
1280 #endif
1281 	struct rw_semaphore alloc_sem;
1282 	unsigned short  bb_counters[];
1283 };
1284 
1285 #define EXT4_GROUP_INFO_NEED_INIT_BIT	0
1286 #define EXT4_GROUP_INFO_LOCKED_BIT	1
1287 
1288 #define EXT4_MB_GRP_NEED_INIT(grp)	\
1289 	(test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
1290 
1291 static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
1292 {
1293 	struct ext4_group_info *grinfo = ext4_get_group_info(sb, group);
1294 
1295 	bit_spin_lock(EXT4_GROUP_INFO_LOCKED_BIT, &(grinfo->bb_state));
1296 }
1297 
1298 static inline void ext4_unlock_group(struct super_block *sb,
1299 					ext4_group_t group)
1300 {
1301 	struct ext4_group_info *grinfo = ext4_get_group_info(sb, group);
1302 
1303 	bit_spin_unlock(EXT4_GROUP_INFO_LOCKED_BIT, &(grinfo->bb_state));
1304 }
1305 
1306 static inline int ext4_is_group_locked(struct super_block *sb,
1307 					ext4_group_t group)
1308 {
1309 	struct ext4_group_info *grinfo = ext4_get_group_info(sb, group);
1310 
1311 	return bit_spin_is_locked(EXT4_GROUP_INFO_LOCKED_BIT,
1312 						&(grinfo->bb_state));
1313 }
1314 
1315 /*
1316  * Inodes and files operations
1317  */
1318 
1319 /* dir.c */
1320 extern const struct file_operations ext4_dir_operations;
1321 
1322 /* file.c */
1323 extern const struct inode_operations ext4_file_inode_operations;
1324 extern const struct file_operations ext4_file_operations;
1325 
1326 /* namei.c */
1327 extern const struct inode_operations ext4_dir_inode_operations;
1328 extern const struct inode_operations ext4_special_inode_operations;
1329 
1330 /* symlink.c */
1331 extern const struct inode_operations ext4_symlink_inode_operations;
1332 extern const struct inode_operations ext4_fast_symlink_inode_operations;
1333 
1334 /* extents.c */
1335 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
1336 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
1337 extern int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks,
1338 				       int chunk);
1339 extern int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
1340 			       ext4_lblk_t iblock, unsigned int max_blocks,
1341 			       struct buffer_head *bh_result,
1342 			       int create, int extend_disksize);
1343 extern void ext4_ext_truncate(struct inode *);
1344 extern void ext4_ext_init(struct super_block *);
1345 extern void ext4_ext_release(struct super_block *);
1346 extern long ext4_fallocate(struct inode *inode, int mode, loff_t offset,
1347 			  loff_t len);
1348 extern int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode,
1349 			sector_t block, unsigned int max_blocks,
1350 			struct buffer_head *bh, int create,
1351 			int extend_disksize, int flag);
1352 extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
1353 			__u64 start, __u64 len);
1354 
1355 /*
1356  * Add new method to test wether block and inode bitmaps are properly
1357  * initialized. With uninit_bg reading the block from disk is not enough
1358  * to mark the bitmap uptodate. We need to also zero-out the bitmap
1359  */
1360 #define BH_BITMAP_UPTODATE BH_JBDPrivateStart
1361 
1362 static inline int bitmap_uptodate(struct buffer_head *bh)
1363 {
1364 	return (buffer_uptodate(bh) &&
1365 			test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
1366 }
1367 static inline void set_bitmap_uptodate(struct buffer_head *bh)
1368 {
1369 	set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
1370 }
1371 
1372 #endif	/* __KERNEL__ */
1373 
1374 #endif	/* _EXT4_H */
1375