xref: /openbmc/linux/fs/ext4/ext4.h (revision 78c99ba1)
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 <linux/rwsem.h>
25 #include <linux/rbtree.h>
26 #include <linux/seqlock.h>
27 #include <linux/mutex.h>
28 #include <linux/timer.h>
29 #include <linux/wait.h>
30 #include <linux/blockgroup_lock.h>
31 #include <linux/percpu_counter.h>
32 
33 /*
34  * The fourth extended filesystem constants/structures
35  */
36 
37 /*
38  * Define EXT4FS_DEBUG to produce debug messages
39  */
40 #undef EXT4FS_DEBUG
41 
42 /*
43  * Debug code
44  */
45 #ifdef EXT4FS_DEBUG
46 #define ext4_debug(f, a...)						\
47 	do {								\
48 		printk(KERN_DEBUG "EXT4-fs DEBUG (%s, %d): %s:",	\
49 			__FILE__, __LINE__, __func__);			\
50 		printk(KERN_DEBUG f, ## a);				\
51 	} while (0)
52 #else
53 #define ext4_debug(f, a...)	do {} while (0)
54 #endif
55 
56 /* data type for block offset of block group */
57 typedef int ext4_grpblk_t;
58 
59 /* data type for filesystem-wide blocks number */
60 typedef unsigned long long ext4_fsblk_t;
61 
62 /* data type for file logical block number */
63 typedef __u32 ext4_lblk_t;
64 
65 /* data type for block group number */
66 typedef unsigned int ext4_group_t;
67 
68 
69 /* prefer goal again. length */
70 #define EXT4_MB_HINT_MERGE		1
71 /* blocks already reserved */
72 #define EXT4_MB_HINT_RESERVED		2
73 /* metadata is being allocated */
74 #define EXT4_MB_HINT_METADATA		4
75 /* first blocks in the file */
76 #define EXT4_MB_HINT_FIRST		8
77 /* search for the best chunk */
78 #define EXT4_MB_HINT_BEST		16
79 /* data is being allocated */
80 #define EXT4_MB_HINT_DATA		32
81 /* don't preallocate (for tails) */
82 #define EXT4_MB_HINT_NOPREALLOC		64
83 /* allocate for locality group */
84 #define EXT4_MB_HINT_GROUP_ALLOC	128
85 /* allocate goal blocks or none */
86 #define EXT4_MB_HINT_GOAL_ONLY		256
87 /* goal is meaningful */
88 #define EXT4_MB_HINT_TRY_GOAL		512
89 /* blocks already pre-reserved by delayed allocation */
90 #define EXT4_MB_DELALLOC_RESERVED      1024
91 
92 
93 struct ext4_allocation_request {
94 	/* target inode for block we're allocating */
95 	struct inode *inode;
96 	/* logical block in target inode */
97 	ext4_lblk_t logical;
98 	/* phys. target (a hint) */
99 	ext4_fsblk_t goal;
100 	/* the closest logical allocated block to the left */
101 	ext4_lblk_t lleft;
102 	/* phys. block for ^^^ */
103 	ext4_fsblk_t pleft;
104 	/* the closest logical allocated block to the right */
105 	ext4_lblk_t lright;
106 	/* phys. block for ^^^ */
107 	ext4_fsblk_t pright;
108 	/* how many blocks we want to allocate */
109 	unsigned int len;
110 	/* flags. see above EXT4_MB_HINT_* */
111 	unsigned int flags;
112 };
113 
114 /*
115  * Special inodes numbers
116  */
117 #define	EXT4_BAD_INO		 1	/* Bad blocks inode */
118 #define EXT4_ROOT_INO		 2	/* Root inode */
119 #define EXT4_BOOT_LOADER_INO	 5	/* Boot loader inode */
120 #define EXT4_UNDEL_DIR_INO	 6	/* Undelete directory inode */
121 #define EXT4_RESIZE_INO		 7	/* Reserved group descriptors inode */
122 #define EXT4_JOURNAL_INO	 8	/* Journal inode */
123 
124 /* First non-reserved inode for old ext4 filesystems */
125 #define EXT4_GOOD_OLD_FIRST_INO	11
126 
127 /*
128  * Maximal count of links to a file
129  */
130 #define EXT4_LINK_MAX		65000
131 
132 /*
133  * Macro-instructions used to manage several block sizes
134  */
135 #define EXT4_MIN_BLOCK_SIZE		1024
136 #define	EXT4_MAX_BLOCK_SIZE		65536
137 #define EXT4_MIN_BLOCK_LOG_SIZE		10
138 #ifdef __KERNEL__
139 # define EXT4_BLOCK_SIZE(s)		((s)->s_blocksize)
140 #else
141 # define EXT4_BLOCK_SIZE(s)		(EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
142 #endif
143 #define	EXT4_ADDR_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / sizeof(__u32))
144 #ifdef __KERNEL__
145 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_blocksize_bits)
146 #else
147 # define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_log_block_size + 10)
148 #endif
149 #ifdef __KERNEL__
150 #define	EXT4_ADDR_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_addr_per_block_bits)
151 #define EXT4_INODE_SIZE(s)		(EXT4_SB(s)->s_inode_size)
152 #define EXT4_FIRST_INO(s)		(EXT4_SB(s)->s_first_ino)
153 #else
154 #define EXT4_INODE_SIZE(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
155 				 EXT4_GOOD_OLD_INODE_SIZE : \
156 				 (s)->s_inode_size)
157 #define EXT4_FIRST_INO(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
158 				 EXT4_GOOD_OLD_FIRST_INO : \
159 				 (s)->s_first_ino)
160 #endif
161 #define EXT4_BLOCK_ALIGN(size, blkbits)		ALIGN((size), (1 << (blkbits)))
162 
163 /*
164  * Structure of a blocks group descriptor
165  */
166 struct ext4_group_desc
167 {
168 	__le32	bg_block_bitmap_lo;	/* Blocks bitmap block */
169 	__le32	bg_inode_bitmap_lo;	/* Inodes bitmap block */
170 	__le32	bg_inode_table_lo;	/* Inodes table block */
171 	__le16	bg_free_blocks_count_lo;/* Free blocks count */
172 	__le16	bg_free_inodes_count_lo;/* Free inodes count */
173 	__le16	bg_used_dirs_count_lo;	/* Directories count */
174 	__le16	bg_flags;		/* EXT4_BG_flags (INODE_UNINIT, etc) */
175 	__u32	bg_reserved[2];		/* Likely block/inode bitmap checksum */
176 	__le16  bg_itable_unused_lo;	/* Unused inodes count */
177 	__le16  bg_checksum;		/* crc16(sb_uuid+group+desc) */
178 	__le32	bg_block_bitmap_hi;	/* Blocks bitmap block MSB */
179 	__le32	bg_inode_bitmap_hi;	/* Inodes bitmap block MSB */
180 	__le32	bg_inode_table_hi;	/* Inodes table block MSB */
181 	__le16	bg_free_blocks_count_hi;/* Free blocks count MSB */
182 	__le16	bg_free_inodes_count_hi;/* Free inodes count MSB */
183 	__le16	bg_used_dirs_count_hi;	/* Directories count MSB */
184 	__le16  bg_itable_unused_hi;    /* Unused inodes count MSB */
185 	__u32	bg_reserved2[3];
186 };
187 
188 /*
189  * Structure of a flex block group info
190  */
191 
192 struct flex_groups {
193 	atomic_t free_inodes;
194 	atomic_t free_blocks;
195 	atomic_t used_dirs;
196 };
197 
198 #define EXT4_BG_INODE_UNINIT	0x0001 /* Inode table/bitmap not in use */
199 #define EXT4_BG_BLOCK_UNINIT	0x0002 /* Block bitmap not in use */
200 #define EXT4_BG_INODE_ZEROED	0x0004 /* On-disk itable initialized to zero */
201 
202 /*
203  * Macro-instructions used to manage group descriptors
204  */
205 #define EXT4_MIN_DESC_SIZE		32
206 #define EXT4_MIN_DESC_SIZE_64BIT	64
207 #define	EXT4_MAX_DESC_SIZE		EXT4_MIN_BLOCK_SIZE
208 #define EXT4_DESC_SIZE(s)		(EXT4_SB(s)->s_desc_size)
209 #ifdef __KERNEL__
210 # define EXT4_BLOCKS_PER_GROUP(s)	(EXT4_SB(s)->s_blocks_per_group)
211 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_SB(s)->s_desc_per_block)
212 # define EXT4_INODES_PER_GROUP(s)	(EXT4_SB(s)->s_inodes_per_group)
213 # define EXT4_DESC_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_desc_per_block_bits)
214 #else
215 # define EXT4_BLOCKS_PER_GROUP(s)	((s)->s_blocks_per_group)
216 # define EXT4_DESC_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
217 # define EXT4_INODES_PER_GROUP(s)	((s)->s_inodes_per_group)
218 #endif
219 
220 /*
221  * Constants relative to the data blocks
222  */
223 #define	EXT4_NDIR_BLOCKS		12
224 #define	EXT4_IND_BLOCK			EXT4_NDIR_BLOCKS
225 #define	EXT4_DIND_BLOCK			(EXT4_IND_BLOCK + 1)
226 #define	EXT4_TIND_BLOCK			(EXT4_DIND_BLOCK + 1)
227 #define	EXT4_N_BLOCKS			(EXT4_TIND_BLOCK + 1)
228 
229 /*
230  * Inode flags
231  */
232 #define	EXT4_SECRM_FL			0x00000001 /* Secure deletion */
233 #define	EXT4_UNRM_FL			0x00000002 /* Undelete */
234 #define	EXT4_COMPR_FL			0x00000004 /* Compress file */
235 #define EXT4_SYNC_FL			0x00000008 /* Synchronous updates */
236 #define EXT4_IMMUTABLE_FL		0x00000010 /* Immutable file */
237 #define EXT4_APPEND_FL			0x00000020 /* writes to file may only append */
238 #define EXT4_NODUMP_FL			0x00000040 /* do not dump file */
239 #define EXT4_NOATIME_FL			0x00000080 /* do not update atime */
240 /* Reserved for compression usage... */
241 #define EXT4_DIRTY_FL			0x00000100
242 #define EXT4_COMPRBLK_FL		0x00000200 /* One or more compressed clusters */
243 #define EXT4_NOCOMPR_FL			0x00000400 /* Don't compress */
244 #define EXT4_ECOMPR_FL			0x00000800 /* Compression error */
245 /* End compression flags --- maybe not all used */
246 #define EXT4_INDEX_FL			0x00001000 /* hash-indexed directory */
247 #define EXT4_IMAGIC_FL			0x00002000 /* AFS directory */
248 #define EXT4_JOURNAL_DATA_FL		0x00004000 /* file data should be journaled */
249 #define EXT4_NOTAIL_FL			0x00008000 /* file tail should not be merged */
250 #define EXT4_DIRSYNC_FL			0x00010000 /* dirsync behaviour (directories only) */
251 #define EXT4_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
252 #define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
253 #define EXT4_EXTENTS_FL			0x00080000 /* Inode uses extents */
254 #define EXT4_EXT_MIGRATE		0x00100000 /* Inode is migrating */
255 #define EXT4_RESERVED_FL		0x80000000 /* reserved for ext4 lib */
256 
257 #define EXT4_FL_USER_VISIBLE		0x000BDFFF /* User visible flags */
258 #define EXT4_FL_USER_MODIFIABLE		0x000B80FF /* User modifiable flags */
259 
260 /* Flags that should be inherited by new inodes from their parent. */
261 #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
262 			   EXT4_SYNC_FL | EXT4_IMMUTABLE_FL | EXT4_APPEND_FL |\
263 			   EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
264 			   EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
265 			   EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL)
266 
267 /* Flags that are appropriate for regular files (all but dir-specific ones). */
268 #define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL))
269 
270 /* Flags that are appropriate for non-directories/regular files. */
271 #define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
272 
273 /* Mask out flags that are inappropriate for the given type of inode. */
274 static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
275 {
276 	if (S_ISDIR(mode))
277 		return flags;
278 	else if (S_ISREG(mode))
279 		return flags & EXT4_REG_FLMASK;
280 	else
281 		return flags & EXT4_OTHER_FLMASK;
282 }
283 
284 /*
285  * Inode dynamic state flags
286  */
287 #define EXT4_STATE_JDATA		0x00000001 /* journaled data exists */
288 #define EXT4_STATE_NEW			0x00000002 /* inode is newly created */
289 #define EXT4_STATE_XATTR		0x00000004 /* has in-inode xattrs */
290 #define EXT4_STATE_NO_EXPAND		0x00000008 /* No space for expansion */
291 #define EXT4_STATE_DA_ALLOC_CLOSE	0x00000010 /* Alloc DA blks on close */
292 
293 /* Used to pass group descriptor data when online resize is done */
294 struct ext4_new_group_input {
295 	__u32 group;		/* Group number for this data */
296 	__u64 block_bitmap;	/* Absolute block number of block bitmap */
297 	__u64 inode_bitmap;	/* Absolute block number of inode bitmap */
298 	__u64 inode_table;	/* Absolute block number of inode table start */
299 	__u32 blocks_count;	/* Total number of blocks in this group */
300 	__u16 reserved_blocks;	/* Number of reserved blocks in this group */
301 	__u16 unused;
302 };
303 
304 /* The struct ext4_new_group_input in kernel space, with free_blocks_count */
305 struct ext4_new_group_data {
306 	__u32 group;
307 	__u64 block_bitmap;
308 	__u64 inode_bitmap;
309 	__u64 inode_table;
310 	__u32 blocks_count;
311 	__u16 reserved_blocks;
312 	__u16 unused;
313 	__u32 free_blocks_count;
314 };
315 
316 /*
317  * Flags used by ext4_get_blocks()
318  */
319 	/* Allocate any needed blocks and/or convert an unitialized
320 	   extent to be an initialized ext4 */
321 #define EXT4_GET_BLOCKS_CREATE			0x0001
322 	/* Request the creation of an unitialized extent */
323 #define EXT4_GET_BLOCKS_UNINIT_EXT		0x0002
324 #define EXT4_GET_BLOCKS_CREATE_UNINIT_EXT	(EXT4_GET_BLOCKS_UNINIT_EXT|\
325 						 EXT4_GET_BLOCKS_CREATE)
326 	/* Caller is from the delayed allocation writeout path,
327 	   so set the magic i_delalloc_reserve_flag after taking the
328 	   inode allocation semaphore for */
329 #define EXT4_GET_BLOCKS_DELALLOC_RESERVE	0x0004
330 	/* Call ext4_da_update_reserve_space() after successfully
331 	   allocating the blocks */
332 #define EXT4_GET_BLOCKS_UPDATE_RESERVE_SPACE	0x0008
333 
334 
335 /*
336  * ioctl commands
337  */
338 #define	EXT4_IOC_GETFLAGS		FS_IOC_GETFLAGS
339 #define	EXT4_IOC_SETFLAGS		FS_IOC_SETFLAGS
340 #define	EXT4_IOC_GETVERSION		_IOR('f', 3, long)
341 #define	EXT4_IOC_SETVERSION		_IOW('f', 4, long)
342 #define	EXT4_IOC_GETVERSION_OLD		FS_IOC_GETVERSION
343 #define	EXT4_IOC_SETVERSION_OLD		FS_IOC_SETVERSION
344 #ifdef CONFIG_JBD2_DEBUG
345 #define EXT4_IOC_WAIT_FOR_READONLY	_IOR('f', 99, long)
346 #endif
347 #define EXT4_IOC_GETRSVSZ		_IOR('f', 5, long)
348 #define EXT4_IOC_SETRSVSZ		_IOW('f', 6, long)
349 #define EXT4_IOC_GROUP_EXTEND		_IOW('f', 7, unsigned long)
350 #define EXT4_IOC_GROUP_ADD		_IOW('f', 8, struct ext4_new_group_input)
351 #define EXT4_IOC_MIGRATE		_IO('f', 9)
352  /* note ioctl 10 reserved for an early version of the FIEMAP ioctl */
353  /* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
354 #define EXT4_IOC_ALLOC_DA_BLKS		_IO('f', 12)
355 
356 /*
357  * ioctl commands in 32 bit emulation
358  */
359 #define EXT4_IOC32_GETFLAGS		FS_IOC32_GETFLAGS
360 #define EXT4_IOC32_SETFLAGS		FS_IOC32_SETFLAGS
361 #define EXT4_IOC32_GETVERSION		_IOR('f', 3, int)
362 #define EXT4_IOC32_SETVERSION		_IOW('f', 4, int)
363 #define EXT4_IOC32_GETRSVSZ		_IOR('f', 5, int)
364 #define EXT4_IOC32_SETRSVSZ		_IOW('f', 6, int)
365 #define EXT4_IOC32_GROUP_EXTEND		_IOW('f', 7, unsigned int)
366 #ifdef CONFIG_JBD2_DEBUG
367 #define EXT4_IOC32_WAIT_FOR_READONLY	_IOR('f', 99, int)
368 #endif
369 #define EXT4_IOC32_GETVERSION_OLD	FS_IOC32_GETVERSION
370 #define EXT4_IOC32_SETVERSION_OLD	FS_IOC32_SETVERSION
371 
372 
373 /*
374  *  Mount options
375  */
376 struct ext4_mount_options {
377 	unsigned long s_mount_opt;
378 	uid_t s_resuid;
379 	gid_t s_resgid;
380 	unsigned long s_commit_interval;
381 	u32 s_min_batch_time, s_max_batch_time;
382 #ifdef CONFIG_QUOTA
383 	int s_jquota_fmt;
384 	char *s_qf_names[MAXQUOTAS];
385 #endif
386 };
387 
388 /*
389  * Structure of an inode on the disk
390  */
391 struct ext4_inode {
392 	__le16	i_mode;		/* File mode */
393 	__le16	i_uid;		/* Low 16 bits of Owner Uid */
394 	__le32	i_size_lo;	/* Size in bytes */
395 	__le32	i_atime;	/* Access time */
396 	__le32	i_ctime;	/* Inode Change time */
397 	__le32	i_mtime;	/* Modification time */
398 	__le32	i_dtime;	/* Deletion Time */
399 	__le16	i_gid;		/* Low 16 bits of Group Id */
400 	__le16	i_links_count;	/* Links count */
401 	__le32	i_blocks_lo;	/* Blocks count */
402 	__le32	i_flags;	/* File flags */
403 	union {
404 		struct {
405 			__le32  l_i_version;
406 		} linux1;
407 		struct {
408 			__u32  h_i_translator;
409 		} hurd1;
410 		struct {
411 			__u32  m_i_reserved1;
412 		} masix1;
413 	} osd1;				/* OS dependent 1 */
414 	__le32	i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
415 	__le32	i_generation;	/* File version (for NFS) */
416 	__le32	i_file_acl_lo;	/* File ACL */
417 	__le32	i_size_high;
418 	__le32	i_obso_faddr;	/* Obsoleted fragment address */
419 	union {
420 		struct {
421 			__le16	l_i_blocks_high; /* were l_i_reserved1 */
422 			__le16	l_i_file_acl_high;
423 			__le16	l_i_uid_high;	/* these 2 fields */
424 			__le16	l_i_gid_high;	/* were reserved2[0] */
425 			__u32	l_i_reserved2;
426 		} linux2;
427 		struct {
428 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
429 			__u16	h_i_mode_high;
430 			__u16	h_i_uid_high;
431 			__u16	h_i_gid_high;
432 			__u32	h_i_author;
433 		} hurd2;
434 		struct {
435 			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
436 			__le16	m_i_file_acl_high;
437 			__u32	m_i_reserved2[2];
438 		} masix2;
439 	} osd2;				/* OS dependent 2 */
440 	__le16	i_extra_isize;
441 	__le16	i_pad1;
442 	__le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
443 	__le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
444 	__le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
445 	__le32  i_crtime;       /* File Creation time */
446 	__le32  i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
447 	__le32  i_version_hi;	/* high 32 bits for 64-bit version */
448 };
449 
450 
451 #define EXT4_EPOCH_BITS 2
452 #define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
453 #define EXT4_NSEC_MASK  (~0UL << EXT4_EPOCH_BITS)
454 
455 /*
456  * Extended fields will fit into an inode if the filesystem was formatted
457  * with large inodes (-I 256 or larger) and there are not currently any EAs
458  * consuming all of the available space. For new inodes we always reserve
459  * enough space for the kernel's known extended fields, but for inodes
460  * created with an old kernel this might not have been the case. None of
461  * the extended inode fields is critical for correct filesystem operation.
462  * This macro checks if a certain field fits in the inode. Note that
463  * inode-size = GOOD_OLD_INODE_SIZE + i_extra_isize
464  */
465 #define EXT4_FITS_IN_INODE(ext4_inode, einode, field)	\
466 	((offsetof(typeof(*ext4_inode), field) +	\
467 	  sizeof((ext4_inode)->field))			\
468 	<= (EXT4_GOOD_OLD_INODE_SIZE +			\
469 	    (einode)->i_extra_isize))			\
470 
471 static inline __le32 ext4_encode_extra_time(struct timespec *time)
472 {
473        return cpu_to_le32((sizeof(time->tv_sec) > 4 ?
474 			   time->tv_sec >> 32 : 0) |
475 			   ((time->tv_nsec << 2) & EXT4_NSEC_MASK));
476 }
477 
478 static inline void ext4_decode_extra_time(struct timespec *time, __le32 extra)
479 {
480        if (sizeof(time->tv_sec) > 4)
481 	       time->tv_sec |= (__u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK)
482 			       << 32;
483        time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> 2;
484 }
485 
486 #define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode)			       \
487 do {									       \
488 	(raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec);	       \
489 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
490 		(raw_inode)->xtime ## _extra =				       \
491 				ext4_encode_extra_time(&(inode)->xtime);       \
492 } while (0)
493 
494 #define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode)			       \
495 do {									       \
496 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
497 		(raw_inode)->xtime = cpu_to_le32((einode)->xtime.tv_sec);      \
498 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
499 		(raw_inode)->xtime ## _extra =				       \
500 				ext4_encode_extra_time(&(einode)->xtime);      \
501 } while (0)
502 
503 #define EXT4_INODE_GET_XTIME(xtime, inode, raw_inode)			       \
504 do {									       \
505 	(inode)->xtime.tv_sec = (signed)le32_to_cpu((raw_inode)->xtime);       \
506 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
507 		ext4_decode_extra_time(&(inode)->xtime,			       \
508 				       raw_inode->xtime ## _extra);	       \
509 } while (0)
510 
511 #define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode)			       \
512 do {									       \
513 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
514 		(einode)->xtime.tv_sec = 				       \
515 			(signed)le32_to_cpu((raw_inode)->xtime);	       \
516 	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
517 		ext4_decode_extra_time(&(einode)->xtime,		       \
518 				       raw_inode->xtime ## _extra);	       \
519 } while (0)
520 
521 #define i_disk_version osd1.linux1.l_i_version
522 
523 #if defined(__KERNEL__) || defined(__linux__)
524 #define i_reserved1	osd1.linux1.l_i_reserved1
525 #define i_file_acl_high	osd2.linux2.l_i_file_acl_high
526 #define i_blocks_high	osd2.linux2.l_i_blocks_high
527 #define i_uid_low	i_uid
528 #define i_gid_low	i_gid
529 #define i_uid_high	osd2.linux2.l_i_uid_high
530 #define i_gid_high	osd2.linux2.l_i_gid_high
531 #define i_reserved2	osd2.linux2.l_i_reserved2
532 
533 #elif defined(__GNU__)
534 
535 #define i_translator	osd1.hurd1.h_i_translator
536 #define i_uid_high	osd2.hurd2.h_i_uid_high
537 #define i_gid_high	osd2.hurd2.h_i_gid_high
538 #define i_author	osd2.hurd2.h_i_author
539 
540 #elif defined(__masix__)
541 
542 #define i_reserved1	osd1.masix1.m_i_reserved1
543 #define i_file_acl_high	osd2.masix2.m_i_file_acl_high
544 #define i_reserved2	osd2.masix2.m_i_reserved2
545 
546 #endif /* defined(__KERNEL__) || defined(__linux__) */
547 
548 /*
549  * storage for cached extent
550  */
551 struct ext4_ext_cache {
552 	ext4_fsblk_t	ec_start;
553 	ext4_lblk_t	ec_block;
554 	__u32		ec_len; /* must be 32bit to return holes */
555 	__u32		ec_type;
556 };
557 
558 /*
559  * fourth extended file system inode data in memory
560  */
561 struct ext4_inode_info {
562 	__le32	i_data[15];	/* unconverted */
563 	__u32	i_flags;
564 	ext4_fsblk_t	i_file_acl;
565 	__u32	i_dtime;
566 
567 	/*
568 	 * i_block_group is the number of the block group which contains
569 	 * this file's inode.  Constant across the lifetime of the inode,
570 	 * it is ued for making block allocation decisions - we try to
571 	 * place a file's data blocks near its inode block, and new inodes
572 	 * near to their parent directory's inode.
573 	 */
574 	ext4_group_t	i_block_group;
575 	__u32	i_state;		/* Dynamic state flags for ext4 */
576 
577 	ext4_lblk_t		i_dir_start_lookup;
578 #ifdef CONFIG_EXT4_FS_XATTR
579 	/*
580 	 * Extended attributes can be read independently of the main file
581 	 * data. Taking i_mutex even when reading would cause contention
582 	 * between readers of EAs and writers of regular file data, so
583 	 * instead we synchronize on xattr_sem when reading or changing
584 	 * EAs.
585 	 */
586 	struct rw_semaphore xattr_sem;
587 #endif
588 #ifdef CONFIG_EXT4_FS_POSIX_ACL
589 	struct posix_acl	*i_acl;
590 	struct posix_acl	*i_default_acl;
591 #endif
592 
593 	struct list_head i_orphan;	/* unlinked but open inodes */
594 
595 	/*
596 	 * i_disksize keeps track of what the inode size is ON DISK, not
597 	 * in memory.  During truncate, i_size is set to the new size by
598 	 * the VFS prior to calling ext4_truncate(), but the filesystem won't
599 	 * set i_disksize to 0 until the truncate is actually under way.
600 	 *
601 	 * The intent is that i_disksize always represents the blocks which
602 	 * are used by this file.  This allows recovery to restart truncate
603 	 * on orphans if we crash during truncate.  We actually write i_disksize
604 	 * into the on-disk inode when writing inodes out, instead of i_size.
605 	 *
606 	 * The only time when i_disksize and i_size may be different is when
607 	 * a truncate is in progress.  The only things which change i_disksize
608 	 * are ext4_get_block (growth) and ext4_truncate (shrinkth).
609 	 */
610 	loff_t	i_disksize;
611 
612 	/*
613 	 * i_data_sem is for serialising ext4_truncate() against
614 	 * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's
615 	 * data tree are chopped off during truncate. We can't do that in
616 	 * ext4 because whenever we perform intermediate commits during
617 	 * truncate, the inode and all the metadata blocks *must* be in a
618 	 * consistent state which allows truncation of the orphans to restart
619 	 * during recovery.  Hence we must fix the get_block-vs-truncate race
620 	 * by other means, so we have i_data_sem.
621 	 */
622 	struct rw_semaphore i_data_sem;
623 	struct inode vfs_inode;
624 	struct jbd2_inode jinode;
625 
626 	struct ext4_ext_cache i_cached_extent;
627 	/*
628 	 * File creation time. Its function is same as that of
629 	 * struct timespec i_{a,c,m}time in the generic inode.
630 	 */
631 	struct timespec i_crtime;
632 
633 	/* mballoc */
634 	struct list_head i_prealloc_list;
635 	spinlock_t i_prealloc_lock;
636 
637 	/* ialloc */
638 	ext4_group_t	i_last_alloc_group;
639 
640 	/* allocation reservation info for delalloc */
641 	unsigned int i_reserved_data_blocks;
642 	unsigned int i_reserved_meta_blocks;
643 	unsigned int i_allocated_meta_blocks;
644 	unsigned short i_delalloc_reserved_flag;
645 
646 	/* on-disk additional length */
647 	__u16 i_extra_isize;
648 
649 	spinlock_t i_block_reservation_lock;
650 };
651 
652 /*
653  * File system states
654  */
655 #define	EXT4_VALID_FS			0x0001	/* Unmounted cleanly */
656 #define	EXT4_ERROR_FS			0x0002	/* Errors detected */
657 #define	EXT4_ORPHAN_FS			0x0004	/* Orphans being recovered */
658 
659 /*
660  * Misc. filesystem flags
661  */
662 #define EXT2_FLAGS_SIGNED_HASH		0x0001  /* Signed dirhash in use */
663 #define EXT2_FLAGS_UNSIGNED_HASH	0x0002  /* Unsigned dirhash in use */
664 #define EXT2_FLAGS_TEST_FILESYS		0x0004	/* to test development code */
665 
666 /*
667  * Mount flags
668  */
669 #define EXT4_MOUNT_OLDALLOC		0x00002  /* Don't use the new Orlov allocator */
670 #define EXT4_MOUNT_GRPID		0x00004	/* Create files with directory's group */
671 #define EXT4_MOUNT_DEBUG		0x00008	/* Some debugging messages */
672 #define EXT4_MOUNT_ERRORS_CONT		0x00010	/* Continue on errors */
673 #define EXT4_MOUNT_ERRORS_RO		0x00020	/* Remount fs ro on errors */
674 #define EXT4_MOUNT_ERRORS_PANIC		0x00040	/* Panic on errors */
675 #define EXT4_MOUNT_MINIX_DF		0x00080	/* Mimics the Minix statfs */
676 #define EXT4_MOUNT_NOLOAD		0x00100	/* Don't use existing journal*/
677 #define EXT4_MOUNT_ABORT		0x00200	/* Fatal error detected */
678 #define EXT4_MOUNT_DATA_FLAGS		0x00C00	/* Mode for data writes: */
679 #define EXT4_MOUNT_JOURNAL_DATA		0x00400	/* Write data to journal */
680 #define EXT4_MOUNT_ORDERED_DATA		0x00800	/* Flush data before commit */
681 #define EXT4_MOUNT_WRITEBACK_DATA	0x00C00	/* No data ordering */
682 #define EXT4_MOUNT_UPDATE_JOURNAL	0x01000	/* Update the journal format */
683 #define EXT4_MOUNT_NO_UID32		0x02000  /* Disable 32-bit UIDs */
684 #define EXT4_MOUNT_XATTR_USER		0x04000	/* Extended user attributes */
685 #define EXT4_MOUNT_POSIX_ACL		0x08000	/* POSIX Access Control Lists */
686 #define EXT4_MOUNT_NO_AUTO_DA_ALLOC	0x10000	/* No auto delalloc mapping */
687 #define EXT4_MOUNT_BARRIER		0x20000 /* Use block barriers */
688 #define EXT4_MOUNT_NOBH			0x40000 /* No bufferheads */
689 #define EXT4_MOUNT_QUOTA		0x80000 /* Some quota option set */
690 #define EXT4_MOUNT_USRQUOTA		0x100000 /* "old" user quota */
691 #define EXT4_MOUNT_GRPQUOTA		0x200000 /* "old" group quota */
692 #define EXT4_MOUNT_JOURNAL_CHECKSUM	0x800000 /* Journal checksums */
693 #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT	0x1000000 /* Journal Async Commit */
694 #define EXT4_MOUNT_I_VERSION            0x2000000 /* i_version support */
695 #define EXT4_MOUNT_DELALLOC		0x8000000 /* Delalloc support */
696 #define EXT4_MOUNT_DATA_ERR_ABORT	0x10000000 /* Abort on file data write */
697 #define EXT4_MOUNT_BLOCK_VALIDITY	0x20000000 /* Block validity checking */
698 
699 /* Compatibility, for having both ext2_fs.h and ext4_fs.h included at once */
700 #ifndef _LINUX_EXT2_FS_H
701 #define clear_opt(o, opt)		o &= ~EXT4_MOUNT_##opt
702 #define set_opt(o, opt)			o |= EXT4_MOUNT_##opt
703 #define test_opt(sb, opt)		(EXT4_SB(sb)->s_mount_opt & \
704 					 EXT4_MOUNT_##opt)
705 #else
706 #define EXT2_MOUNT_NOLOAD		EXT4_MOUNT_NOLOAD
707 #define EXT2_MOUNT_ABORT		EXT4_MOUNT_ABORT
708 #define EXT2_MOUNT_DATA_FLAGS		EXT4_MOUNT_DATA_FLAGS
709 #endif
710 
711 #define ext4_set_bit			ext2_set_bit
712 #define ext4_set_bit_atomic		ext2_set_bit_atomic
713 #define ext4_clear_bit			ext2_clear_bit
714 #define ext4_clear_bit_atomic		ext2_clear_bit_atomic
715 #define ext4_test_bit			ext2_test_bit
716 #define ext4_find_first_zero_bit	ext2_find_first_zero_bit
717 #define ext4_find_next_zero_bit		ext2_find_next_zero_bit
718 #define ext4_find_next_bit		ext2_find_next_bit
719 
720 /*
721  * Maximal mount counts between two filesystem checks
722  */
723 #define EXT4_DFL_MAX_MNT_COUNT		20	/* Allow 20 mounts */
724 #define EXT4_DFL_CHECKINTERVAL		0	/* Don't use interval check */
725 
726 /*
727  * Behaviour when detecting errors
728  */
729 #define EXT4_ERRORS_CONTINUE		1	/* Continue execution */
730 #define EXT4_ERRORS_RO			2	/* Remount fs read-only */
731 #define EXT4_ERRORS_PANIC		3	/* Panic */
732 #define EXT4_ERRORS_DEFAULT		EXT4_ERRORS_CONTINUE
733 
734 /*
735  * Structure of the super block
736  */
737 struct ext4_super_block {
738 /*00*/	__le32	s_inodes_count;		/* Inodes count */
739 	__le32	s_blocks_count_lo;	/* Blocks count */
740 	__le32	s_r_blocks_count_lo;	/* Reserved blocks count */
741 	__le32	s_free_blocks_count_lo;	/* Free blocks count */
742 /*10*/	__le32	s_free_inodes_count;	/* Free inodes count */
743 	__le32	s_first_data_block;	/* First Data Block */
744 	__le32	s_log_block_size;	/* Block size */
745 	__le32	s_obso_log_frag_size;	/* Obsoleted fragment size */
746 /*20*/	__le32	s_blocks_per_group;	/* # Blocks per group */
747 	__le32	s_obso_frags_per_group;	/* Obsoleted fragments per group */
748 	__le32	s_inodes_per_group;	/* # Inodes per group */
749 	__le32	s_mtime;		/* Mount time */
750 /*30*/	__le32	s_wtime;		/* Write time */
751 	__le16	s_mnt_count;		/* Mount count */
752 	__le16	s_max_mnt_count;	/* Maximal mount count */
753 	__le16	s_magic;		/* Magic signature */
754 	__le16	s_state;		/* File system state */
755 	__le16	s_errors;		/* Behaviour when detecting errors */
756 	__le16	s_minor_rev_level;	/* minor revision level */
757 /*40*/	__le32	s_lastcheck;		/* time of last check */
758 	__le32	s_checkinterval;	/* max. time between checks */
759 	__le32	s_creator_os;		/* OS */
760 	__le32	s_rev_level;		/* Revision level */
761 /*50*/	__le16	s_def_resuid;		/* Default uid for reserved blocks */
762 	__le16	s_def_resgid;		/* Default gid for reserved blocks */
763 	/*
764 	 * These fields are for EXT4_DYNAMIC_REV superblocks only.
765 	 *
766 	 * Note: the difference between the compatible feature set and
767 	 * the incompatible feature set is that if there is a bit set
768 	 * in the incompatible feature set that the kernel doesn't
769 	 * know about, it should refuse to mount the filesystem.
770 	 *
771 	 * e2fsck's requirements are more strict; if it doesn't know
772 	 * about a feature in either the compatible or incompatible
773 	 * feature set, it must abort and not try to meddle with
774 	 * things it doesn't understand...
775 	 */
776 	__le32	s_first_ino;		/* First non-reserved inode */
777 	__le16  s_inode_size;		/* size of inode structure */
778 	__le16	s_block_group_nr;	/* block group # of this superblock */
779 	__le32	s_feature_compat;	/* compatible feature set */
780 /*60*/	__le32	s_feature_incompat;	/* incompatible feature set */
781 	__le32	s_feature_ro_compat;	/* readonly-compatible feature set */
782 /*68*/	__u8	s_uuid[16];		/* 128-bit uuid for volume */
783 /*78*/	char	s_volume_name[16];	/* volume name */
784 /*88*/	char	s_last_mounted[64];	/* directory where last mounted */
785 /*C8*/	__le32	s_algorithm_usage_bitmap; /* For compression */
786 	/*
787 	 * Performance hints.  Directory preallocation should only
788 	 * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
789 	 */
790 	__u8	s_prealloc_blocks;	/* Nr of blocks to try to preallocate*/
791 	__u8	s_prealloc_dir_blocks;	/* Nr to preallocate for dirs */
792 	__le16	s_reserved_gdt_blocks;	/* Per group desc for online growth */
793 	/*
794 	 * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
795 	 */
796 /*D0*/	__u8	s_journal_uuid[16];	/* uuid of journal superblock */
797 /*E0*/	__le32	s_journal_inum;		/* inode number of journal file */
798 	__le32	s_journal_dev;		/* device number of journal file */
799 	__le32	s_last_orphan;		/* start of list of inodes to delete */
800 	__le32	s_hash_seed[4];		/* HTREE hash seed */
801 	__u8	s_def_hash_version;	/* Default hash version to use */
802 	__u8	s_reserved_char_pad;
803 	__le16  s_desc_size;		/* size of group descriptor */
804 /*100*/	__le32	s_default_mount_opts;
805 	__le32	s_first_meta_bg;	/* First metablock block group */
806 	__le32	s_mkfs_time;		/* When the filesystem was created */
807 	__le32	s_jnl_blocks[17];	/* Backup of the journal inode */
808 	/* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
809 /*150*/	__le32	s_blocks_count_hi;	/* Blocks count */
810 	__le32	s_r_blocks_count_hi;	/* Reserved blocks count */
811 	__le32	s_free_blocks_count_hi;	/* Free blocks count */
812 	__le16	s_min_extra_isize;	/* All inodes have at least # bytes */
813 	__le16	s_want_extra_isize; 	/* New inodes should reserve # bytes */
814 	__le32	s_flags;		/* Miscellaneous flags */
815 	__le16  s_raid_stride;		/* RAID stride */
816 	__le16  s_mmp_interval;         /* # seconds to wait in MMP checking */
817 	__le64  s_mmp_block;            /* Block for multi-mount protection */
818 	__le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
819 	__u8	s_log_groups_per_flex;  /* FLEX_BG group size */
820 	__u8	s_reserved_char_pad2;
821 	__le16  s_reserved_pad;
822 	__le64	s_kbytes_written;	/* nr of lifetime kilobytes written */
823 	__u32   s_reserved[160];        /* Padding to the end of the block */
824 };
825 
826 #ifdef __KERNEL__
827 /*
828  * fourth extended-fs super-block data in memory
829  */
830 struct ext4_sb_info {
831 	unsigned long s_desc_size;	/* Size of a group descriptor in bytes */
832 	unsigned long s_inodes_per_block;/* Number of inodes per block */
833 	unsigned long s_blocks_per_group;/* Number of blocks in a group */
834 	unsigned long s_inodes_per_group;/* Number of inodes in a group */
835 	unsigned long s_itb_per_group;	/* Number of inode table blocks per group */
836 	unsigned long s_gdb_count;	/* Number of group descriptor blocks */
837 	unsigned long s_desc_per_block;	/* Number of group descriptors per block */
838 	ext4_group_t s_groups_count;	/* Number of groups in the fs */
839 	unsigned long s_overhead_last;  /* Last calculated overhead */
840 	unsigned long s_blocks_last;    /* Last seen block count */
841 	loff_t s_bitmap_maxbytes;	/* max bytes for bitmap files */
842 	struct buffer_head * s_sbh;	/* Buffer containing the super block */
843 	struct ext4_super_block *s_es;	/* Pointer to the super block in the buffer */
844 	struct buffer_head **s_group_desc;
845 	unsigned long  s_mount_opt;
846 	ext4_fsblk_t s_sb_block;
847 	uid_t s_resuid;
848 	gid_t s_resgid;
849 	unsigned short s_mount_state;
850 	unsigned short s_pad;
851 	int s_addr_per_block_bits;
852 	int s_desc_per_block_bits;
853 	int s_inode_size;
854 	int s_first_ino;
855 	unsigned int s_inode_readahead_blks;
856 	spinlock_t s_next_gen_lock;
857 	u32 s_next_generation;
858 	u32 s_hash_seed[4];
859 	int s_def_hash_version;
860 	int s_hash_unsigned;	/* 3 if hash should be signed, 0 if not */
861 	struct percpu_counter s_freeblocks_counter;
862 	struct percpu_counter s_freeinodes_counter;
863 	struct percpu_counter s_dirs_counter;
864 	struct percpu_counter s_dirtyblocks_counter;
865 	struct blockgroup_lock *s_blockgroup_lock;
866 	struct proc_dir_entry *s_proc;
867 	struct kobject s_kobj;
868 	struct completion s_kobj_unregister;
869 
870 	/* Journaling */
871 	struct inode *s_journal_inode;
872 	struct journal_s *s_journal;
873 	struct list_head s_orphan;
874 	struct mutex s_orphan_lock;
875 	struct mutex s_resize_lock;
876 	unsigned long s_commit_interval;
877 	u32 s_max_batch_time;
878 	u32 s_min_batch_time;
879 	struct block_device *journal_bdev;
880 #ifdef CONFIG_JBD2_DEBUG
881 	struct timer_list turn_ro_timer;	/* For turning read-only (crash simulation) */
882 	wait_queue_head_t ro_wait_queue;	/* For people waiting for the fs to go read-only */
883 #endif
884 #ifdef CONFIG_QUOTA
885 	char *s_qf_names[MAXQUOTAS];		/* Names of quota files with journalled quota */
886 	int s_jquota_fmt;			/* Format of quota to use */
887 #endif
888 	unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
889 	struct rb_root system_blks;
890 
891 #ifdef EXTENTS_STATS
892 	/* ext4 extents stats */
893 	unsigned long s_ext_min;
894 	unsigned long s_ext_max;
895 	unsigned long s_depth_max;
896 	spinlock_t s_ext_stats_lock;
897 	unsigned long s_ext_blocks;
898 	unsigned long s_ext_extents;
899 #endif
900 
901 	/* for buddy allocator */
902 	struct ext4_group_info ***s_group_info;
903 	struct inode *s_buddy_cache;
904 	long s_blocks_reserved;
905 	spinlock_t s_reserve_lock;
906 	spinlock_t s_md_lock;
907 	tid_t s_last_transaction;
908 	unsigned short *s_mb_offsets;
909 	unsigned int *s_mb_maxs;
910 
911 	/* tunables */
912 	unsigned long s_stripe;
913 	unsigned int s_mb_stream_request;
914 	unsigned int s_mb_max_to_scan;
915 	unsigned int s_mb_min_to_scan;
916 	unsigned int s_mb_stats;
917 	unsigned int s_mb_order2_reqs;
918 	unsigned int s_mb_group_prealloc;
919 	/* where last allocation was done - for stream allocation */
920 	unsigned long s_mb_last_group;
921 	unsigned long s_mb_last_start;
922 
923 	/* history to debug policy */
924 	struct ext4_mb_history *s_mb_history;
925 	int s_mb_history_cur;
926 	int s_mb_history_max;
927 	int s_mb_history_num;
928 	spinlock_t s_mb_history_lock;
929 	int s_mb_history_filter;
930 
931 	/* stats for buddy allocator */
932 	spinlock_t s_mb_pa_lock;
933 	atomic_t s_bal_reqs;	/* number of reqs with len > 1 */
934 	atomic_t s_bal_success;	/* we found long enough chunks */
935 	atomic_t s_bal_allocated;	/* in blocks */
936 	atomic_t s_bal_ex_scanned;	/* total extents scanned */
937 	atomic_t s_bal_goals;	/* goal hits */
938 	atomic_t s_bal_breaks;	/* too long searches */
939 	atomic_t s_bal_2orders;	/* 2^order hits */
940 	spinlock_t s_bal_lock;
941 	unsigned long s_mb_buddies_generated;
942 	unsigned long long s_mb_generation_time;
943 	atomic_t s_mb_lost_chunks;
944 	atomic_t s_mb_preallocated;
945 	atomic_t s_mb_discarded;
946 
947 	/* locality groups */
948 	struct ext4_locality_group *s_locality_groups;
949 
950 	/* for write statistics */
951 	unsigned long s_sectors_written_start;
952 	u64 s_kbytes_written;
953 
954 	unsigned int s_log_groups_per_flex;
955 	struct flex_groups *s_flex_groups;
956 };
957 
958 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
959 {
960 	return sb->s_fs_info;
961 }
962 static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
963 {
964 	return container_of(inode, struct ext4_inode_info, vfs_inode);
965 }
966 
967 static inline struct timespec ext4_current_time(struct inode *inode)
968 {
969 	return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
970 		current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
971 }
972 
973 static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
974 {
975 	return ino == EXT4_ROOT_INO ||
976 		ino == EXT4_JOURNAL_INO ||
977 		ino == EXT4_RESIZE_INO ||
978 		(ino >= EXT4_FIRST_INO(sb) &&
979 		 ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
980 }
981 #else
982 /* Assume that user mode programs are passing in an ext4fs superblock, not
983  * a kernel struct super_block.  This will allow us to call the feature-test
984  * macros from user land. */
985 #define EXT4_SB(sb)	(sb)
986 #endif
987 
988 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
989 
990 /*
991  * Codes for operating systems
992  */
993 #define EXT4_OS_LINUX		0
994 #define EXT4_OS_HURD		1
995 #define EXT4_OS_MASIX		2
996 #define EXT4_OS_FREEBSD		3
997 #define EXT4_OS_LITES		4
998 
999 /*
1000  * Revision levels
1001  */
1002 #define EXT4_GOOD_OLD_REV	0	/* The good old (original) format */
1003 #define EXT4_DYNAMIC_REV	1	/* V2 format w/ dynamic inode sizes */
1004 
1005 #define EXT4_CURRENT_REV	EXT4_GOOD_OLD_REV
1006 #define EXT4_MAX_SUPP_REV	EXT4_DYNAMIC_REV
1007 
1008 #define EXT4_GOOD_OLD_INODE_SIZE 128
1009 
1010 /*
1011  * Feature set definitions
1012  */
1013 
1014 #define EXT4_HAS_COMPAT_FEATURE(sb,mask)			\
1015 	((EXT4_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask)) != 0)
1016 #define EXT4_HAS_RO_COMPAT_FEATURE(sb,mask)			\
1017 	((EXT4_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask)) != 0)
1018 #define EXT4_HAS_INCOMPAT_FEATURE(sb,mask)			\
1019 	((EXT4_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask)) != 0)
1020 #define EXT4_SET_COMPAT_FEATURE(sb,mask)			\
1021 	EXT4_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
1022 #define EXT4_SET_RO_COMPAT_FEATURE(sb,mask)			\
1023 	EXT4_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
1024 #define EXT4_SET_INCOMPAT_FEATURE(sb,mask)			\
1025 	EXT4_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
1026 #define EXT4_CLEAR_COMPAT_FEATURE(sb,mask)			\
1027 	EXT4_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
1028 #define EXT4_CLEAR_RO_COMPAT_FEATURE(sb,mask)			\
1029 	EXT4_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
1030 #define EXT4_CLEAR_INCOMPAT_FEATURE(sb,mask)			\
1031 	EXT4_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
1032 
1033 #define EXT4_FEATURE_COMPAT_DIR_PREALLOC	0x0001
1034 #define EXT4_FEATURE_COMPAT_IMAGIC_INODES	0x0002
1035 #define EXT4_FEATURE_COMPAT_HAS_JOURNAL		0x0004
1036 #define EXT4_FEATURE_COMPAT_EXT_ATTR		0x0008
1037 #define EXT4_FEATURE_COMPAT_RESIZE_INODE	0x0010
1038 #define EXT4_FEATURE_COMPAT_DIR_INDEX		0x0020
1039 
1040 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
1041 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
1042 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR	0x0004
1043 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
1044 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM		0x0010
1045 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK	0x0020
1046 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE	0x0040
1047 
1048 #define EXT4_FEATURE_INCOMPAT_COMPRESSION	0x0001
1049 #define EXT4_FEATURE_INCOMPAT_FILETYPE		0x0002
1050 #define EXT4_FEATURE_INCOMPAT_RECOVER		0x0004 /* Needs recovery */
1051 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008 /* Journal device */
1052 #define EXT4_FEATURE_INCOMPAT_META_BG		0x0010
1053 #define EXT4_FEATURE_INCOMPAT_EXTENTS		0x0040 /* extents support */
1054 #define EXT4_FEATURE_INCOMPAT_64BIT		0x0080
1055 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
1056 #define EXT4_FEATURE_INCOMPAT_FLEX_BG		0x0200
1057 
1058 #define EXT4_FEATURE_COMPAT_SUPP	EXT2_FEATURE_COMPAT_EXT_ATTR
1059 #define EXT4_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
1060 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
1061 					 EXT4_FEATURE_INCOMPAT_META_BG| \
1062 					 EXT4_FEATURE_INCOMPAT_EXTENTS| \
1063 					 EXT4_FEATURE_INCOMPAT_64BIT| \
1064 					 EXT4_FEATURE_INCOMPAT_FLEX_BG)
1065 #define EXT4_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1066 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1067 					 EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
1068 					 EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
1069 					 EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
1070 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
1071 					 EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
1072 
1073 /*
1074  * Default values for user and/or group using reserved blocks
1075  */
1076 #define	EXT4_DEF_RESUID		0
1077 #define	EXT4_DEF_RESGID		0
1078 
1079 #define EXT4_DEF_INODE_READAHEAD_BLKS	32
1080 
1081 /*
1082  * Default mount options
1083  */
1084 #define EXT4_DEFM_DEBUG		0x0001
1085 #define EXT4_DEFM_BSDGROUPS	0x0002
1086 #define EXT4_DEFM_XATTR_USER	0x0004
1087 #define EXT4_DEFM_ACL		0x0008
1088 #define EXT4_DEFM_UID16		0x0010
1089 #define EXT4_DEFM_JMODE		0x0060
1090 #define EXT4_DEFM_JMODE_DATA	0x0020
1091 #define EXT4_DEFM_JMODE_ORDERED	0x0040
1092 #define EXT4_DEFM_JMODE_WBACK	0x0060
1093 
1094 /*
1095  * Default journal batch times
1096  */
1097 #define EXT4_DEF_MIN_BATCH_TIME	0
1098 #define EXT4_DEF_MAX_BATCH_TIME	15000 /* 15ms */
1099 
1100 /*
1101  * Minimum number of groups in a flexgroup before we separate out
1102  * directories into the first block group of a flexgroup
1103  */
1104 #define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME	4
1105 
1106 /*
1107  * Structure of a directory entry
1108  */
1109 #define EXT4_NAME_LEN 255
1110 
1111 struct ext4_dir_entry {
1112 	__le32	inode;			/* Inode number */
1113 	__le16	rec_len;		/* Directory entry length */
1114 	__le16	name_len;		/* Name length */
1115 	char	name[EXT4_NAME_LEN];	/* File name */
1116 };
1117 
1118 /*
1119  * The new version of the directory entry.  Since EXT4 structures are
1120  * stored in intel byte order, and the name_len field could never be
1121  * bigger than 255 chars, it's safe to reclaim the extra byte for the
1122  * file_type field.
1123  */
1124 struct ext4_dir_entry_2 {
1125 	__le32	inode;			/* Inode number */
1126 	__le16	rec_len;		/* Directory entry length */
1127 	__u8	name_len;		/* Name length */
1128 	__u8	file_type;
1129 	char	name[EXT4_NAME_LEN];	/* File name */
1130 };
1131 
1132 /*
1133  * Ext4 directory file types.  Only the low 3 bits are used.  The
1134  * other bits are reserved for now.
1135  */
1136 #define EXT4_FT_UNKNOWN		0
1137 #define EXT4_FT_REG_FILE	1
1138 #define EXT4_FT_DIR		2
1139 #define EXT4_FT_CHRDEV		3
1140 #define EXT4_FT_BLKDEV		4
1141 #define EXT4_FT_FIFO		5
1142 #define EXT4_FT_SOCK		6
1143 #define EXT4_FT_SYMLINK		7
1144 
1145 #define EXT4_FT_MAX		8
1146 
1147 /*
1148  * EXT4_DIR_PAD defines the directory entries boundaries
1149  *
1150  * NOTE: It must be a multiple of 4
1151  */
1152 #define EXT4_DIR_PAD			4
1153 #define EXT4_DIR_ROUND			(EXT4_DIR_PAD - 1)
1154 #define EXT4_DIR_REC_LEN(name_len)	(((name_len) + 8 + EXT4_DIR_ROUND) & \
1155 					 ~EXT4_DIR_ROUND)
1156 #define EXT4_MAX_REC_LEN		((1<<16)-1)
1157 
1158 /*
1159  * Hash Tree Directory indexing
1160  * (c) Daniel Phillips, 2001
1161  */
1162 
1163 #define is_dx(dir) (EXT4_HAS_COMPAT_FEATURE(dir->i_sb, \
1164 				      EXT4_FEATURE_COMPAT_DIR_INDEX) && \
1165 		      (EXT4_I(dir)->i_flags & EXT4_INDEX_FL))
1166 #define EXT4_DIR_LINK_MAX(dir) (!is_dx(dir) && (dir)->i_nlink >= EXT4_LINK_MAX)
1167 #define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
1168 
1169 /* Legal values for the dx_root hash_version field: */
1170 
1171 #define DX_HASH_LEGACY		0
1172 #define DX_HASH_HALF_MD4	1
1173 #define DX_HASH_TEA		2
1174 #define DX_HASH_LEGACY_UNSIGNED	3
1175 #define DX_HASH_HALF_MD4_UNSIGNED	4
1176 #define DX_HASH_TEA_UNSIGNED		5
1177 
1178 #ifdef __KERNEL__
1179 
1180 /* hash info structure used by the directory hash */
1181 struct dx_hash_info
1182 {
1183 	u32		hash;
1184 	u32		minor_hash;
1185 	int		hash_version;
1186 	u32		*seed;
1187 };
1188 
1189 #define EXT4_HTREE_EOF	0x7fffffff
1190 
1191 /*
1192  * Control parameters used by ext4_htree_next_block
1193  */
1194 #define HASH_NB_ALWAYS		1
1195 
1196 
1197 /*
1198  * Describe an inode's exact location on disk and in memory
1199  */
1200 struct ext4_iloc
1201 {
1202 	struct buffer_head *bh;
1203 	unsigned long offset;
1204 	ext4_group_t block_group;
1205 };
1206 
1207 static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
1208 {
1209 	return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
1210 }
1211 
1212 /*
1213  * This structure is stuffed into the struct file's private_data field
1214  * for directories.  It is where we put information so that we can do
1215  * readdir operations in hash tree order.
1216  */
1217 struct dir_private_info {
1218 	struct rb_root	root;
1219 	struct rb_node	*curr_node;
1220 	struct fname	*extra_fname;
1221 	loff_t		last_pos;
1222 	__u32		curr_hash;
1223 	__u32		curr_minor_hash;
1224 	__u32		next_hash;
1225 };
1226 
1227 /* calculate the first block number of the group */
1228 static inline ext4_fsblk_t
1229 ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
1230 {
1231 	return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
1232 		le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
1233 }
1234 
1235 /*
1236  * Special error return code only used by dx_probe() and its callers.
1237  */
1238 #define ERR_BAD_DX_DIR	-75000
1239 
1240 void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,
1241 			ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp);
1242 
1243 extern struct proc_dir_entry *ext4_proc_root;
1244 
1245 /*
1246  * Function prototypes
1247  */
1248 
1249 /*
1250  * Ok, these declarations are also in <linux/kernel.h> but none of the
1251  * ext4 source programs needs to include it so they are duplicated here.
1252  */
1253 # define NORET_TYPE	/**/
1254 # define ATTRIB_NORET	__attribute__((noreturn))
1255 # define NORET_AND	noreturn,
1256 
1257 /* bitmap.c */
1258 extern unsigned int ext4_count_free(struct buffer_head *, unsigned);
1259 
1260 /* balloc.c */
1261 extern unsigned int ext4_block_group(struct super_block *sb,
1262 			ext4_fsblk_t blocknr);
1263 extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
1264 			ext4_fsblk_t blocknr);
1265 extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
1266 extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
1267 			ext4_group_t group);
1268 extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
1269 			ext4_fsblk_t goal, unsigned long *count, int *errp);
1270 extern int ext4_claim_free_blocks(struct ext4_sb_info *sbi, s64 nblocks);
1271 extern int ext4_has_free_blocks(struct ext4_sb_info *sbi, s64 nblocks);
1272 extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
1273 			ext4_fsblk_t block, unsigned long count, int metadata);
1274 extern void ext4_add_groupblocks(handle_t *handle, struct super_block *sb,
1275 				ext4_fsblk_t block, unsigned long count);
1276 extern ext4_fsblk_t ext4_count_free_blocks(struct super_block *);
1277 extern void ext4_check_blocks_bitmap(struct super_block *);
1278 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
1279 						    ext4_group_t block_group,
1280 						    struct buffer_head ** bh);
1281 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
1282 struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
1283 				      ext4_group_t block_group);
1284 extern unsigned ext4_init_block_bitmap(struct super_block *sb,
1285 				       struct buffer_head *bh,
1286 				       ext4_group_t group,
1287 				       struct ext4_group_desc *desc);
1288 #define ext4_free_blocks_after_init(sb, group, desc)			\
1289 		ext4_init_block_bitmap(sb, NULL, group, desc)
1290 
1291 /* dir.c */
1292 extern int ext4_check_dir_entry(const char *, struct inode *,
1293 				struct ext4_dir_entry_2 *,
1294 				struct buffer_head *, unsigned int);
1295 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
1296 				    __u32 minor_hash,
1297 				    struct ext4_dir_entry_2 *dirent);
1298 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
1299 
1300 /* fsync.c */
1301 extern int ext4_sync_file(struct file *, struct dentry *, int);
1302 
1303 /* hash.c */
1304 extern int ext4fs_dirhash(const char *name, int len, struct
1305 			  dx_hash_info *hinfo);
1306 
1307 /* ialloc.c */
1308 extern struct inode * ext4_new_inode(handle_t *, struct inode *, int);
1309 extern void ext4_free_inode(handle_t *, struct inode *);
1310 extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
1311 extern unsigned long ext4_count_free_inodes(struct super_block *);
1312 extern unsigned long ext4_count_dirs(struct super_block *);
1313 extern void ext4_check_inodes_bitmap(struct super_block *);
1314 extern unsigned ext4_init_inode_bitmap(struct super_block *sb,
1315 				       struct buffer_head *bh,
1316 				       ext4_group_t group,
1317 				       struct ext4_group_desc *desc);
1318 extern void mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
1319 
1320 /* mballoc.c */
1321 extern long ext4_mb_stats;
1322 extern long ext4_mb_max_to_scan;
1323 extern int ext4_mb_init(struct super_block *, int);
1324 extern int ext4_mb_release(struct super_block *);
1325 extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
1326 				struct ext4_allocation_request *, int *);
1327 extern int ext4_mb_reserve_blocks(struct super_block *, int);
1328 extern void ext4_discard_preallocations(struct inode *);
1329 extern int __init init_ext4_mballoc(void);
1330 extern void exit_ext4_mballoc(void);
1331 extern void ext4_mb_free_blocks(handle_t *, struct inode *,
1332 		unsigned long, unsigned long, int, unsigned long *);
1333 extern int ext4_mb_add_groupinfo(struct super_block *sb,
1334 		ext4_group_t i, struct ext4_group_desc *desc);
1335 extern void ext4_mb_update_group_info(struct ext4_group_info *grp,
1336 		ext4_grpblk_t add);
1337 extern int ext4_mb_get_buddy_cache_lock(struct super_block *, ext4_group_t);
1338 extern void ext4_mb_put_buddy_cache_lock(struct super_block *,
1339 						ext4_group_t, int);
1340 /* inode.c */
1341 int ext4_forget(handle_t *handle, int is_metadata, struct inode *inode,
1342 		struct buffer_head *bh, ext4_fsblk_t blocknr);
1343 struct buffer_head *ext4_getblk(handle_t *, struct inode *,
1344 						ext4_lblk_t, int, int *);
1345 struct buffer_head *ext4_bread(handle_t *, struct inode *,
1346 						ext4_lblk_t, int, int *);
1347 int ext4_get_block(struct inode *inode, sector_t iblock,
1348 				struct buffer_head *bh_result, int create);
1349 
1350 extern struct inode *ext4_iget(struct super_block *, unsigned long);
1351 extern int  ext4_write_inode(struct inode *, int);
1352 extern int  ext4_setattr(struct dentry *, struct iattr *);
1353 extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
1354 				struct kstat *stat);
1355 extern void ext4_delete_inode(struct inode *);
1356 extern int  ext4_sync_inode(handle_t *, struct inode *);
1357 extern void ext4_dirty_inode(struct inode *);
1358 extern int ext4_change_inode_journal_flag(struct inode *, int);
1359 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
1360 extern int ext4_can_truncate(struct inode *inode);
1361 extern void ext4_truncate(struct inode *);
1362 extern void ext4_set_inode_flags(struct inode *);
1363 extern void ext4_get_inode_flags(struct ext4_inode_info *);
1364 extern int ext4_alloc_da_blocks(struct inode *inode);
1365 extern void ext4_set_aops(struct inode *inode);
1366 extern int ext4_writepage_trans_blocks(struct inode *);
1367 extern int ext4_meta_trans_blocks(struct inode *, int nrblocks, int idxblocks);
1368 extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
1369 extern int ext4_block_truncate_page(handle_t *handle,
1370 		struct address_space *mapping, loff_t from);
1371 extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
1372 extern qsize_t ext4_get_reserved_space(struct inode *inode);
1373 
1374 /* ioctl.c */
1375 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
1376 extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
1377 
1378 /* migrate.c */
1379 extern int ext4_ext_migrate(struct inode *);
1380 
1381 /* namei.c */
1382 extern unsigned int ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize);
1383 extern __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize);
1384 extern int ext4_orphan_add(handle_t *, struct inode *);
1385 extern int ext4_orphan_del(handle_t *, struct inode *);
1386 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1387 				__u32 start_minor_hash, __u32 *next_hash);
1388 
1389 /* resize.c */
1390 extern int ext4_group_add(struct super_block *sb,
1391 				struct ext4_new_group_data *input);
1392 extern int ext4_group_extend(struct super_block *sb,
1393 				struct ext4_super_block *es,
1394 				ext4_fsblk_t n_blocks_count);
1395 
1396 /* super.c */
1397 extern void ext4_error(struct super_block *, const char *, const char *, ...)
1398 	__attribute__ ((format (printf, 3, 4)));
1399 extern void __ext4_std_error(struct super_block *, const char *, int);
1400 extern void ext4_abort(struct super_block *, const char *, const char *, ...)
1401 	__attribute__ ((format (printf, 3, 4)));
1402 extern void ext4_warning(struct super_block *, const char *, const char *, ...)
1403 	__attribute__ ((format (printf, 3, 4)));
1404 extern void ext4_msg(struct super_block *, const char *, const char *, ...)
1405 	__attribute__ ((format (printf, 3, 4)));
1406 extern void ext4_grp_locked_error(struct super_block *, ext4_group_t,
1407 				const char *, const char *, ...)
1408 	__attribute__ ((format (printf, 4, 5)));
1409 extern void ext4_update_dynamic_rev(struct super_block *sb);
1410 extern int ext4_update_compat_feature(handle_t *handle, struct super_block *sb,
1411 					__u32 compat);
1412 extern int ext4_update_rocompat_feature(handle_t *handle,
1413 					struct super_block *sb,	__u32 rocompat);
1414 extern int ext4_update_incompat_feature(handle_t *handle,
1415 					struct super_block *sb,	__u32 incompat);
1416 extern ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
1417 				      struct ext4_group_desc *bg);
1418 extern ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
1419 				      struct ext4_group_desc *bg);
1420 extern ext4_fsblk_t ext4_inode_table(struct super_block *sb,
1421 				     struct ext4_group_desc *bg);
1422 extern __u32 ext4_free_blks_count(struct super_block *sb,
1423 				struct ext4_group_desc *bg);
1424 extern __u32 ext4_free_inodes_count(struct super_block *sb,
1425 				 struct ext4_group_desc *bg);
1426 extern __u32 ext4_used_dirs_count(struct super_block *sb,
1427 				struct ext4_group_desc *bg);
1428 extern __u32 ext4_itable_unused_count(struct super_block *sb,
1429 				   struct ext4_group_desc *bg);
1430 extern void ext4_block_bitmap_set(struct super_block *sb,
1431 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
1432 extern void ext4_inode_bitmap_set(struct super_block *sb,
1433 				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
1434 extern void ext4_inode_table_set(struct super_block *sb,
1435 				 struct ext4_group_desc *bg, ext4_fsblk_t blk);
1436 extern void ext4_free_blks_set(struct super_block *sb,
1437 			       struct ext4_group_desc *bg, __u32 count);
1438 extern void ext4_free_inodes_set(struct super_block *sb,
1439 				struct ext4_group_desc *bg, __u32 count);
1440 extern void ext4_used_dirs_set(struct super_block *sb,
1441 				struct ext4_group_desc *bg, __u32 count);
1442 extern void ext4_itable_unused_set(struct super_block *sb,
1443 				   struct ext4_group_desc *bg, __u32 count);
1444 extern __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 group,
1445 				   struct ext4_group_desc *gdp);
1446 extern int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 group,
1447 				       struct ext4_group_desc *gdp);
1448 
1449 static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
1450 {
1451 	return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |
1452 		le32_to_cpu(es->s_blocks_count_lo);
1453 }
1454 
1455 static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
1456 {
1457 	return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |
1458 		le32_to_cpu(es->s_r_blocks_count_lo);
1459 }
1460 
1461 static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
1462 {
1463 	return ((ext4_fsblk_t)le32_to_cpu(es->s_free_blocks_count_hi) << 32) |
1464 		le32_to_cpu(es->s_free_blocks_count_lo);
1465 }
1466 
1467 static inline void ext4_blocks_count_set(struct ext4_super_block *es,
1468 					 ext4_fsblk_t blk)
1469 {
1470 	es->s_blocks_count_lo = cpu_to_le32((u32)blk);
1471 	es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
1472 }
1473 
1474 static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
1475 					      ext4_fsblk_t blk)
1476 {
1477 	es->s_free_blocks_count_lo = cpu_to_le32((u32)blk);
1478 	es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
1479 }
1480 
1481 static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
1482 					   ext4_fsblk_t blk)
1483 {
1484 	es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
1485 	es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
1486 }
1487 
1488 static inline loff_t ext4_isize(struct ext4_inode *raw_inode)
1489 {
1490 	if (S_ISREG(le16_to_cpu(raw_inode->i_mode)))
1491 		return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
1492 			le32_to_cpu(raw_inode->i_size_lo);
1493 	else
1494 		return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
1495 }
1496 
1497 static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
1498 {
1499 	raw_inode->i_size_lo = cpu_to_le32(i_size);
1500 	raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
1501 }
1502 
1503 static inline
1504 struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
1505 					    ext4_group_t group)
1506 {
1507 	 struct ext4_group_info ***grp_info;
1508 	 long indexv, indexh;
1509 	 grp_info = EXT4_SB(sb)->s_group_info;
1510 	 indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
1511 	 indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
1512 	 return grp_info[indexv][indexh];
1513 }
1514 
1515 /*
1516  * Reading s_groups_count requires using smp_rmb() afterwards.  See
1517  * the locking protocol documented in the comments of ext4_group_add()
1518  * in resize.c
1519  */
1520 static inline ext4_group_t ext4_get_groups_count(struct super_block *sb)
1521 {
1522 	ext4_group_t	ngroups = EXT4_SB(sb)->s_groups_count;
1523 
1524 	smp_rmb();
1525 	return ngroups;
1526 }
1527 
1528 static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
1529 					     ext4_group_t block_group)
1530 {
1531 	return block_group >> sbi->s_log_groups_per_flex;
1532 }
1533 
1534 static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
1535 {
1536 	return 1 << sbi->s_log_groups_per_flex;
1537 }
1538 
1539 #define ext4_std_error(sb, errno)				\
1540 do {								\
1541 	if ((errno))						\
1542 		__ext4_std_error((sb), __func__, (errno));	\
1543 } while (0)
1544 
1545 #ifdef CONFIG_SMP
1546 /* Each CPU can accumulate percpu_counter_batch blocks in their local
1547  * counters. So we need to make sure we have free blocks more
1548  * than percpu_counter_batch  * nr_cpu_ids. Also add a window of 4 times.
1549  */
1550 #define EXT4_FREEBLOCKS_WATERMARK (4 * (percpu_counter_batch * nr_cpu_ids))
1551 #else
1552 #define EXT4_FREEBLOCKS_WATERMARK 0
1553 #endif
1554 
1555 static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
1556 {
1557 	/*
1558 	 * XXX: replace with spinlock if seen contended -bzzz
1559 	 */
1560 	down_write(&EXT4_I(inode)->i_data_sem);
1561 	if (newsize > EXT4_I(inode)->i_disksize)
1562 		EXT4_I(inode)->i_disksize = newsize;
1563 	up_write(&EXT4_I(inode)->i_data_sem);
1564 	return ;
1565 }
1566 
1567 struct ext4_group_info {
1568 	unsigned long   bb_state;
1569 	struct rb_root  bb_free_root;
1570 	unsigned short  bb_first_free;
1571 	unsigned short  bb_free;
1572 	unsigned short  bb_fragments;
1573 	struct          list_head bb_prealloc_list;
1574 #ifdef DOUBLE_CHECK
1575 	void            *bb_bitmap;
1576 #endif
1577 	struct rw_semaphore alloc_sem;
1578 	unsigned short  bb_counters[];
1579 };
1580 
1581 #define EXT4_GROUP_INFO_NEED_INIT_BIT	0
1582 
1583 #define EXT4_MB_GRP_NEED_INIT(grp)	\
1584 	(test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
1585 
1586 static inline spinlock_t *ext4_group_lock_ptr(struct super_block *sb,
1587 					      ext4_group_t group)
1588 {
1589 	return bgl_lock_ptr(EXT4_SB(sb)->s_blockgroup_lock, group);
1590 }
1591 
1592 static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
1593 {
1594 	spin_lock(ext4_group_lock_ptr(sb, group));
1595 }
1596 
1597 static inline void ext4_unlock_group(struct super_block *sb,
1598 					ext4_group_t group)
1599 {
1600 	spin_unlock(ext4_group_lock_ptr(sb, group));
1601 }
1602 
1603 /*
1604  * Inodes and files operations
1605  */
1606 
1607 /* dir.c */
1608 extern const struct file_operations ext4_dir_operations;
1609 
1610 /* file.c */
1611 extern const struct inode_operations ext4_file_inode_operations;
1612 extern const struct file_operations ext4_file_operations;
1613 
1614 /* namei.c */
1615 extern const struct inode_operations ext4_dir_inode_operations;
1616 extern const struct inode_operations ext4_special_inode_operations;
1617 extern struct dentry *ext4_get_parent(struct dentry *child);
1618 
1619 /* symlink.c */
1620 extern const struct inode_operations ext4_symlink_inode_operations;
1621 extern const struct inode_operations ext4_fast_symlink_inode_operations;
1622 
1623 /* block_validity */
1624 extern void ext4_release_system_zone(struct super_block *sb);
1625 extern int ext4_setup_system_zone(struct super_block *sb);
1626 extern int __init init_ext4_system_zone(void);
1627 extern void exit_ext4_system_zone(void);
1628 extern int ext4_data_block_valid(struct ext4_sb_info *sbi,
1629 				 ext4_fsblk_t start_blk,
1630 				 unsigned int count);
1631 
1632 /* extents.c */
1633 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
1634 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
1635 extern int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks,
1636 				       int chunk);
1637 extern int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
1638 			       ext4_lblk_t iblock, unsigned int max_blocks,
1639 			       struct buffer_head *bh_result, int flags);
1640 extern void ext4_ext_truncate(struct inode *);
1641 extern void ext4_ext_init(struct super_block *);
1642 extern void ext4_ext_release(struct super_block *);
1643 extern long ext4_fallocate(struct inode *inode, int mode, loff_t offset,
1644 			  loff_t len);
1645 extern int ext4_get_blocks(handle_t *handle, struct inode *inode,
1646 			   sector_t block, unsigned int max_blocks,
1647 			   struct buffer_head *bh, int flags);
1648 extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
1649 			__u64 start, __u64 len);
1650 
1651 /*
1652  * Add new method to test wether block and inode bitmaps are properly
1653  * initialized. With uninit_bg reading the block from disk is not enough
1654  * to mark the bitmap uptodate. We need to also zero-out the bitmap
1655  */
1656 #define BH_BITMAP_UPTODATE BH_JBDPrivateStart
1657 
1658 static inline int bitmap_uptodate(struct buffer_head *bh)
1659 {
1660 	return (buffer_uptodate(bh) &&
1661 			test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
1662 }
1663 static inline void set_bitmap_uptodate(struct buffer_head *bh)
1664 {
1665 	set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
1666 }
1667 
1668 #endif	/* __KERNEL__ */
1669 
1670 #endif	/* _EXT4_H */
1671