[PATCH] ext4: allow larger descriptor size
[firefly-linux-kernel-4.4.55.git] / include / linux / ext4_fs.h
1 /*
2  *  linux/include/linux/ext4_fs.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 _LINUX_EXT4_FS_H
17 #define _LINUX_EXT4_FS_H
18
19 #include <linux/types.h>
20 #include <linux/blkdev.h>
21 #include <linux/magic.h>
22
23 /*
24  * The second extended filesystem constants/structures
25  */
26
27 /*
28  * Define EXT4FS_DEBUG to produce debug messages
29  */
30 #undef EXT4FS_DEBUG
31
32 /*
33  * Define EXT4_RESERVATION to reserve data blocks for expanding files
34  */
35 #define EXT4_DEFAULT_RESERVE_BLOCKS     8
36 /*max window size: 1024(direct blocks) + 3([t,d]indirect blocks) */
37 #define EXT4_MAX_RESERVE_BLOCKS         1027
38 #define EXT4_RESERVE_WINDOW_NOT_ALLOCATED 0
39 /*
40  * Always enable hashed directories
41  */
42 #define CONFIG_EXT4_INDEX
43
44 /*
45  * Debug code
46  */
47 #ifdef EXT4FS_DEBUG
48 #define ext4_debug(f, a...)                                             \
49         do {                                                            \
50                 printk (KERN_DEBUG "EXT4-fs DEBUG (%s, %d): %s:",       \
51                         __FILE__, __LINE__, __FUNCTION__);              \
52                 printk (KERN_DEBUG f, ## a);                            \
53         } while (0)
54 #else
55 #define ext4_debug(f, a...)     do {} while (0)
56 #endif
57
58 /*
59  * Special inodes numbers
60  */
61 #define EXT4_BAD_INO             1      /* Bad blocks inode */
62 #define EXT4_ROOT_INO            2      /* Root inode */
63 #define EXT4_BOOT_LOADER_INO     5      /* Boot loader inode */
64 #define EXT4_UNDEL_DIR_INO       6      /* Undelete directory inode */
65 #define EXT4_RESIZE_INO          7      /* Reserved group descriptors inode */
66 #define EXT4_JOURNAL_INO         8      /* Journal inode */
67
68 /* First non-reserved inode for old ext4 filesystems */
69 #define EXT4_GOOD_OLD_FIRST_INO 11
70
71 /*
72  * Maximal count of links to a file
73  */
74 #define EXT4_LINK_MAX           32000
75
76 /*
77  * Macro-instructions used to manage several block sizes
78  */
79 #define EXT4_MIN_BLOCK_SIZE             1024
80 #define EXT4_MAX_BLOCK_SIZE             4096
81 #define EXT4_MIN_BLOCK_LOG_SIZE           10
82 #ifdef __KERNEL__
83 # define EXT4_BLOCK_SIZE(s)             ((s)->s_blocksize)
84 #else
85 # define EXT4_BLOCK_SIZE(s)             (EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
86 #endif
87 #define EXT4_ADDR_PER_BLOCK(s)          (EXT4_BLOCK_SIZE(s) / sizeof (__u32))
88 #ifdef __KERNEL__
89 # define EXT4_BLOCK_SIZE_BITS(s)        ((s)->s_blocksize_bits)
90 #else
91 # define EXT4_BLOCK_SIZE_BITS(s)        ((s)->s_log_block_size + 10)
92 #endif
93 #ifdef __KERNEL__
94 #define EXT4_ADDR_PER_BLOCK_BITS(s)     (EXT4_SB(s)->s_addr_per_block_bits)
95 #define EXT4_INODE_SIZE(s)              (EXT4_SB(s)->s_inode_size)
96 #define EXT4_FIRST_INO(s)               (EXT4_SB(s)->s_first_ino)
97 #else
98 #define EXT4_INODE_SIZE(s)      (((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
99                                  EXT4_GOOD_OLD_INODE_SIZE : \
100                                  (s)->s_inode_size)
101 #define EXT4_FIRST_INO(s)       (((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
102                                  EXT4_GOOD_OLD_FIRST_INO : \
103                                  (s)->s_first_ino)
104 #endif
105
106 /*
107  * Macro-instructions used to manage fragments
108  */
109 #define EXT4_MIN_FRAG_SIZE              1024
110 #define EXT4_MAX_FRAG_SIZE              4096
111 #define EXT4_MIN_FRAG_LOG_SIZE            10
112 #ifdef __KERNEL__
113 # define EXT4_FRAG_SIZE(s)              (EXT4_SB(s)->s_frag_size)
114 # define EXT4_FRAGS_PER_BLOCK(s)        (EXT4_SB(s)->s_frags_per_block)
115 #else
116 # define EXT4_FRAG_SIZE(s)              (EXT4_MIN_FRAG_SIZE << (s)->s_log_frag_size)
117 # define EXT4_FRAGS_PER_BLOCK(s)        (EXT4_BLOCK_SIZE(s) / EXT4_FRAG_SIZE(s))
118 #endif
119
120 /*
121  * Structure of a blocks group descriptor
122  */
123 struct ext4_group_desc
124 {
125         __le32  bg_block_bitmap;                /* Blocks bitmap block */
126         __le32  bg_inode_bitmap;                /* Inodes bitmap block */
127         __le32  bg_inode_table;         /* Inodes table block */
128         __le16  bg_free_blocks_count;   /* Free blocks count */
129         __le16  bg_free_inodes_count;   /* Free inodes count */
130         __le16  bg_used_dirs_count;     /* Directories count */
131         __u16   bg_flags;
132         __le16  bg_block_bitmap_hi;     /* Blocks bitmap block MSB */
133         __le16  bg_inode_bitmap_hi;     /* Inodes bitmap block MSB */
134         __le16  bg_inode_table_hi;      /* Inodes table block MSB */
135         __u16   bg_reserved[3];
136 };
137
138 #ifdef __KERNEL__
139 #include <linux/ext4_fs_i.h>
140 #include <linux/ext4_fs_sb.h>
141 #endif
142 /*
143  * Macro-instructions used to manage group descriptors
144  */
145 #define EXT4_MIN_DESC_SIZE              32
146 #define EXT4_MAX_DESC_SIZE              EXT4_MIN_BLOCK_SIZE
147 #define EXT4_DESC_SIZE(s)               (EXT4_SB(s)->s_desc_size)
148 #ifdef __KERNEL__
149 # define EXT4_BLOCKS_PER_GROUP(s)       (EXT4_SB(s)->s_blocks_per_group)
150 # define EXT4_DESC_PER_BLOCK(s)         (EXT4_SB(s)->s_desc_per_block)
151 # define EXT4_INODES_PER_GROUP(s)       (EXT4_SB(s)->s_inodes_per_group)
152 # define EXT4_DESC_PER_BLOCK_BITS(s)    (EXT4_SB(s)->s_desc_per_block_bits)
153 #else
154 # define EXT4_BLOCKS_PER_GROUP(s)       ((s)->s_blocks_per_group)
155 # define EXT4_DESC_PER_BLOCK(s)         (EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
156 # define EXT4_INODES_PER_GROUP(s)       ((s)->s_inodes_per_group)
157 #endif
158
159 /*
160  * Constants relative to the data blocks
161  */
162 #define EXT4_NDIR_BLOCKS                12
163 #define EXT4_IND_BLOCK                  EXT4_NDIR_BLOCKS
164 #define EXT4_DIND_BLOCK                 (EXT4_IND_BLOCK + 1)
165 #define EXT4_TIND_BLOCK                 (EXT4_DIND_BLOCK + 1)
166 #define EXT4_N_BLOCKS                   (EXT4_TIND_BLOCK + 1)
167
168 /*
169  * Inode flags
170  */
171 #define EXT4_SECRM_FL                   0x00000001 /* Secure deletion */
172 #define EXT4_UNRM_FL                    0x00000002 /* Undelete */
173 #define EXT4_COMPR_FL                   0x00000004 /* Compress file */
174 #define EXT4_SYNC_FL                    0x00000008 /* Synchronous updates */
175 #define EXT4_IMMUTABLE_FL               0x00000010 /* Immutable file */
176 #define EXT4_APPEND_FL                  0x00000020 /* writes to file may only append */
177 #define EXT4_NODUMP_FL                  0x00000040 /* do not dump file */
178 #define EXT4_NOATIME_FL                 0x00000080 /* do not update atime */
179 /* Reserved for compression usage... */
180 #define EXT4_DIRTY_FL                   0x00000100
181 #define EXT4_COMPRBLK_FL                0x00000200 /* One or more compressed clusters */
182 #define EXT4_NOCOMPR_FL                 0x00000400 /* Don't compress */
183 #define EXT4_ECOMPR_FL                  0x00000800 /* Compression error */
184 /* End compression flags --- maybe not all used */
185 #define EXT4_INDEX_FL                   0x00001000 /* hash-indexed directory */
186 #define EXT4_IMAGIC_FL                  0x00002000 /* AFS directory */
187 #define EXT4_JOURNAL_DATA_FL            0x00004000 /* file data should be journaled */
188 #define EXT4_NOTAIL_FL                  0x00008000 /* file tail should not be merged */
189 #define EXT4_DIRSYNC_FL                 0x00010000 /* dirsync behaviour (directories only) */
190 #define EXT4_TOPDIR_FL                  0x00020000 /* Top of directory hierarchies*/
191 #define EXT4_RESERVED_FL                0x80000000 /* reserved for ext4 lib */
192 #define EXT4_EXTENTS_FL                 0x00080000 /* Inode uses extents */
193
194 #define EXT4_FL_USER_VISIBLE            0x000BDFFF /* User visible flags */
195 #define EXT4_FL_USER_MODIFIABLE         0x000380FF /* User modifiable flags */
196
197 /*
198  * Inode dynamic state flags
199  */
200 #define EXT4_STATE_JDATA                0x00000001 /* journaled data exists */
201 #define EXT4_STATE_NEW                  0x00000002 /* inode is newly created */
202 #define EXT4_STATE_XATTR                0x00000004 /* has in-inode xattrs */
203
204 /* Used to pass group descriptor data when online resize is done */
205 struct ext4_new_group_input {
206         __u32 group;            /* Group number for this data */
207         __u64 block_bitmap;     /* Absolute block number of block bitmap */
208         __u64 inode_bitmap;     /* Absolute block number of inode bitmap */
209         __u64 inode_table;      /* Absolute block number of inode table start */
210         __u32 blocks_count;     /* Total number of blocks in this group */
211         __u16 reserved_blocks;  /* Number of reserved blocks in this group */
212         __u16 unused;
213 };
214
215 /* The struct ext4_new_group_input in kernel space, with free_blocks_count */
216 struct ext4_new_group_data {
217         __u32 group;
218         __u64 block_bitmap;
219         __u64 inode_bitmap;
220         __u64 inode_table;
221         __u32 blocks_count;
222         __u16 reserved_blocks;
223         __u16 unused;
224         __u32 free_blocks_count;
225 };
226
227
228 /*
229  * ioctl commands
230  */
231 #define EXT4_IOC_GETFLAGS               FS_IOC_GETFLAGS
232 #define EXT4_IOC_SETFLAGS               FS_IOC_SETFLAGS
233 #define EXT4_IOC_GETVERSION             _IOR('f', 3, long)
234 #define EXT4_IOC_SETVERSION             _IOW('f', 4, long)
235 #define EXT4_IOC_GROUP_EXTEND           _IOW('f', 7, unsigned long)
236 #define EXT4_IOC_GROUP_ADD              _IOW('f', 8,struct ext4_new_group_input)
237 #define EXT4_IOC_GETVERSION_OLD         FS_IOC_GETVERSION
238 #define EXT4_IOC_SETVERSION_OLD         FS_IOC_SETVERSION
239 #ifdef CONFIG_JBD_DEBUG
240 #define EXT4_IOC_WAIT_FOR_READONLY      _IOR('f', 99, long)
241 #endif
242 #define EXT4_IOC_GETRSVSZ               _IOR('f', 5, long)
243 #define EXT4_IOC_SETRSVSZ               _IOW('f', 6, long)
244
245 /*
246  * ioctl commands in 32 bit emulation
247  */
248 #define EXT4_IOC32_GETFLAGS             FS_IOC32_GETFLAGS
249 #define EXT4_IOC32_SETFLAGS             FS_IOC32_SETFLAGS
250 #define EXT4_IOC32_GETVERSION           _IOR('f', 3, int)
251 #define EXT4_IOC32_SETVERSION           _IOW('f', 4, int)
252 #define EXT4_IOC32_GETRSVSZ             _IOR('f', 5, int)
253 #define EXT4_IOC32_SETRSVSZ             _IOW('f', 6, int)
254 #define EXT4_IOC32_GROUP_EXTEND         _IOW('f', 7, unsigned int)
255 #ifdef CONFIG_JBD_DEBUG
256 #define EXT4_IOC32_WAIT_FOR_READONLY    _IOR('f', 99, int)
257 #endif
258 #define EXT4_IOC32_GETVERSION_OLD       FS_IOC32_GETVERSION
259 #define EXT4_IOC32_SETVERSION_OLD       FS_IOC32_SETVERSION
260
261
262 /*
263  *  Mount options
264  */
265 struct ext4_mount_options {
266         unsigned long s_mount_opt;
267         uid_t s_resuid;
268         gid_t s_resgid;
269         unsigned long s_commit_interval;
270 #ifdef CONFIG_QUOTA
271         int s_jquota_fmt;
272         char *s_qf_names[MAXQUOTAS];
273 #endif
274 };
275
276 /*
277  * Structure of an inode on the disk
278  */
279 struct ext4_inode {
280         __le16  i_mode;         /* File mode */
281         __le16  i_uid;          /* Low 16 bits of Owner Uid */
282         __le32  i_size;         /* Size in bytes */
283         __le32  i_atime;        /* Access time */
284         __le32  i_ctime;        /* Creation time */
285         __le32  i_mtime;        /* Modification time */
286         __le32  i_dtime;        /* Deletion Time */
287         __le16  i_gid;          /* Low 16 bits of Group Id */
288         __le16  i_links_count;  /* Links count */
289         __le32  i_blocks;       /* Blocks count */
290         __le32  i_flags;        /* File flags */
291         union {
292                 struct {
293                         __u32  l_i_reserved1;
294                 } linux1;
295                 struct {
296                         __u32  h_i_translator;
297                 } hurd1;
298                 struct {
299                         __u32  m_i_reserved1;
300                 } masix1;
301         } osd1;                         /* OS dependent 1 */
302         __le32  i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
303         __le32  i_generation;   /* File version (for NFS) */
304         __le32  i_file_acl;     /* File ACL */
305         __le32  i_dir_acl;      /* Directory ACL */
306         __le32  i_faddr;        /* Fragment address */
307         union {
308                 struct {
309                         __u8    l_i_frag;       /* Fragment number */
310                         __u8    l_i_fsize;      /* Fragment size */
311                         __le16  l_i_file_acl_high;
312                         __le16  l_i_uid_high;   /* these 2 fields    */
313                         __le16  l_i_gid_high;   /* were reserved2[0] */
314                         __u32   l_i_reserved2;
315                 } linux2;
316                 struct {
317                         __u8    h_i_frag;       /* Fragment number */
318                         __u8    h_i_fsize;      /* Fragment size */
319                         __u16   h_i_mode_high;
320                         __u16   h_i_uid_high;
321                         __u16   h_i_gid_high;
322                         __u32   h_i_author;
323                 } hurd2;
324                 struct {
325                         __u8    m_i_frag;       /* Fragment number */
326                         __u8    m_i_fsize;      /* Fragment size */
327                         __le16  m_i_file_acl_high;
328                         __u32   m_i_reserved2[2];
329                 } masix2;
330         } osd2;                         /* OS dependent 2 */
331         __le16  i_extra_isize;
332         __le16  i_pad1;
333 };
334
335 #define i_size_high     i_dir_acl
336
337 #if defined(__KERNEL__) || defined(__linux__)
338 #define i_reserved1     osd1.linux1.l_i_reserved1
339 #define i_frag          osd2.linux2.l_i_frag
340 #define i_fsize         osd2.linux2.l_i_fsize
341 #define i_file_acl_high osd2.linux2.l_i_file_acl_high
342 #define i_uid_low       i_uid
343 #define i_gid_low       i_gid
344 #define i_uid_high      osd2.linux2.l_i_uid_high
345 #define i_gid_high      osd2.linux2.l_i_gid_high
346 #define i_reserved2     osd2.linux2.l_i_reserved2
347
348 #elif defined(__GNU__)
349
350 #define i_translator    osd1.hurd1.h_i_translator
351 #define i_frag          osd2.hurd2.h_i_frag;
352 #define i_fsize         osd2.hurd2.h_i_fsize;
353 #define i_uid_high      osd2.hurd2.h_i_uid_high
354 #define i_gid_high      osd2.hurd2.h_i_gid_high
355 #define i_author        osd2.hurd2.h_i_author
356
357 #elif defined(__masix__)
358
359 #define i_reserved1     osd1.masix1.m_i_reserved1
360 #define i_frag          osd2.masix2.m_i_frag
361 #define i_fsize         osd2.masix2.m_i_fsize
362 #define i_file_acl_high osd2.masix2.m_i_file_acl_high
363 #define i_reserved2     osd2.masix2.m_i_reserved2
364
365 #endif /* defined(__KERNEL__) || defined(__linux__) */
366
367 /*
368  * File system states
369  */
370 #define EXT4_VALID_FS                   0x0001  /* Unmounted cleanly */
371 #define EXT4_ERROR_FS                   0x0002  /* Errors detected */
372 #define EXT4_ORPHAN_FS                  0x0004  /* Orphans being recovered */
373
374 /*
375  * Mount flags
376  */
377 #define EXT4_MOUNT_CHECK                0x00001 /* Do mount-time checks */
378 #define EXT4_MOUNT_OLDALLOC             0x00002  /* Don't use the new Orlov allocator */
379 #define EXT4_MOUNT_GRPID                0x00004 /* Create files with directory's group */
380 #define EXT4_MOUNT_DEBUG                0x00008 /* Some debugging messages */
381 #define EXT4_MOUNT_ERRORS_CONT          0x00010 /* Continue on errors */
382 #define EXT4_MOUNT_ERRORS_RO            0x00020 /* Remount fs ro on errors */
383 #define EXT4_MOUNT_ERRORS_PANIC         0x00040 /* Panic on errors */
384 #define EXT4_MOUNT_MINIX_DF             0x00080 /* Mimics the Minix statfs */
385 #define EXT4_MOUNT_NOLOAD               0x00100 /* Don't use existing journal*/
386 #define EXT4_MOUNT_ABORT                0x00200 /* Fatal error detected */
387 #define EXT4_MOUNT_DATA_FLAGS           0x00C00 /* Mode for data writes: */
388 #define EXT4_MOUNT_JOURNAL_DATA         0x00400 /* Write data to journal */
389 #define EXT4_MOUNT_ORDERED_DATA         0x00800 /* Flush data before commit */
390 #define EXT4_MOUNT_WRITEBACK_DATA       0x00C00 /* No data ordering */
391 #define EXT4_MOUNT_UPDATE_JOURNAL       0x01000 /* Update the journal format */
392 #define EXT4_MOUNT_NO_UID32             0x02000  /* Disable 32-bit UIDs */
393 #define EXT4_MOUNT_XATTR_USER           0x04000 /* Extended user attributes */
394 #define EXT4_MOUNT_POSIX_ACL            0x08000 /* POSIX Access Control Lists */
395 #define EXT4_MOUNT_RESERVATION          0x10000 /* Preallocation */
396 #define EXT4_MOUNT_BARRIER              0x20000 /* Use block barriers */
397 #define EXT4_MOUNT_NOBH                 0x40000 /* No bufferheads */
398 #define EXT4_MOUNT_QUOTA                0x80000 /* Some quota option set */
399 #define EXT4_MOUNT_USRQUOTA             0x100000 /* "old" user quota */
400 #define EXT4_MOUNT_GRPQUOTA             0x200000 /* "old" group quota */
401 #define EXT4_MOUNT_EXTENTS              0x400000 /* Extents support */
402
403 /* Compatibility, for having both ext2_fs.h and ext4_fs.h included at once */
404 #ifndef _LINUX_EXT2_FS_H
405 #define clear_opt(o, opt)               o &= ~EXT4_MOUNT_##opt
406 #define set_opt(o, opt)                 o |= EXT4_MOUNT_##opt
407 #define test_opt(sb, opt)               (EXT4_SB(sb)->s_mount_opt & \
408                                          EXT4_MOUNT_##opt)
409 #else
410 #define EXT2_MOUNT_NOLOAD               EXT4_MOUNT_NOLOAD
411 #define EXT2_MOUNT_ABORT                EXT4_MOUNT_ABORT
412 #define EXT2_MOUNT_DATA_FLAGS           EXT4_MOUNT_DATA_FLAGS
413 #endif
414
415 #define ext4_set_bit                    ext2_set_bit
416 #define ext4_set_bit_atomic             ext2_set_bit_atomic
417 #define ext4_clear_bit                  ext2_clear_bit
418 #define ext4_clear_bit_atomic           ext2_clear_bit_atomic
419 #define ext4_test_bit                   ext2_test_bit
420 #define ext4_find_first_zero_bit        ext2_find_first_zero_bit
421 #define ext4_find_next_zero_bit         ext2_find_next_zero_bit
422
423 /*
424  * Maximal mount counts between two filesystem checks
425  */
426 #define EXT4_DFL_MAX_MNT_COUNT          20      /* Allow 20 mounts */
427 #define EXT4_DFL_CHECKINTERVAL          0       /* Don't use interval check */
428
429 /*
430  * Behaviour when detecting errors
431  */
432 #define EXT4_ERRORS_CONTINUE            1       /* Continue execution */
433 #define EXT4_ERRORS_RO                  2       /* Remount fs read-only */
434 #define EXT4_ERRORS_PANIC               3       /* Panic */
435 #define EXT4_ERRORS_DEFAULT             EXT4_ERRORS_CONTINUE
436
437 /*
438  * Structure of the super block
439  */
440 struct ext4_super_block {
441 /*00*/  __le32  s_inodes_count;         /* Inodes count */
442         __le32  s_blocks_count;         /* Blocks count */
443         __le32  s_r_blocks_count;       /* Reserved blocks count */
444         __le32  s_free_blocks_count;    /* Free blocks count */
445 /*10*/  __le32  s_free_inodes_count;    /* Free inodes count */
446         __le32  s_first_data_block;     /* First Data Block */
447         __le32  s_log_block_size;       /* Block size */
448         __le32  s_log_frag_size;        /* Fragment size */
449 /*20*/  __le32  s_blocks_per_group;     /* # Blocks per group */
450         __le32  s_frags_per_group;      /* # Fragments per group */
451         __le32  s_inodes_per_group;     /* # Inodes per group */
452         __le32  s_mtime;                /* Mount time */
453 /*30*/  __le32  s_wtime;                /* Write time */
454         __le16  s_mnt_count;            /* Mount count */
455         __le16  s_max_mnt_count;        /* Maximal mount count */
456         __le16  s_magic;                /* Magic signature */
457         __le16  s_state;                /* File system state */
458         __le16  s_errors;               /* Behaviour when detecting errors */
459         __le16  s_minor_rev_level;      /* minor revision level */
460 /*40*/  __le32  s_lastcheck;            /* time of last check */
461         __le32  s_checkinterval;        /* max. time between checks */
462         __le32  s_creator_os;           /* OS */
463         __le32  s_rev_level;            /* Revision level */
464 /*50*/  __le16  s_def_resuid;           /* Default uid for reserved blocks */
465         __le16  s_def_resgid;           /* Default gid for reserved blocks */
466         /*
467          * These fields are for EXT4_DYNAMIC_REV superblocks only.
468          *
469          * Note: the difference between the compatible feature set and
470          * the incompatible feature set is that if there is a bit set
471          * in the incompatible feature set that the kernel doesn't
472          * know about, it should refuse to mount the filesystem.
473          *
474          * e2fsck's requirements are more strict; if it doesn't know
475          * about a feature in either the compatible or incompatible
476          * feature set, it must abort and not try to meddle with
477          * things it doesn't understand...
478          */
479         __le32  s_first_ino;            /* First non-reserved inode */
480         __le16  s_inode_size;           /* size of inode structure */
481         __le16  s_block_group_nr;       /* block group # of this superblock */
482         __le32  s_feature_compat;       /* compatible feature set */
483 /*60*/  __le32  s_feature_incompat;     /* incompatible feature set */
484         __le32  s_feature_ro_compat;    /* readonly-compatible feature set */
485 /*68*/  __u8    s_uuid[16];             /* 128-bit uuid for volume */
486 /*78*/  char    s_volume_name[16];      /* volume name */
487 /*88*/  char    s_last_mounted[64];     /* directory where last mounted */
488 /*C8*/  __le32  s_algorithm_usage_bitmap; /* For compression */
489         /*
490          * Performance hints.  Directory preallocation should only
491          * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
492          */
493         __u8    s_prealloc_blocks;      /* Nr of blocks to try to preallocate*/
494         __u8    s_prealloc_dir_blocks;  /* Nr to preallocate for dirs */
495         __le16  s_reserved_gdt_blocks;  /* Per group desc for online growth */
496         /*
497          * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
498          */
499 /*D0*/  __u8    s_journal_uuid[16];     /* uuid of journal superblock */
500 /*E0*/  __le32  s_journal_inum;         /* inode number of journal file */
501         __le32  s_journal_dev;          /* device number of journal file */
502         __le32  s_last_orphan;          /* start of list of inodes to delete */
503         __le32  s_hash_seed[4];         /* HTREE hash seed */
504         __u8    s_def_hash_version;     /* Default hash version to use */
505         __u8    s_reserved_char_pad;
506         __le16  s_desc_size;            /* size of group descriptor */
507 /*100*/ __le32  s_default_mount_opts;
508         __le32  s_first_meta_bg;        /* First metablock block group */
509         __le32  s_mkfs_time;            /* When the filesystem was created */
510         __le32  s_jnl_blocks[17];       /* Backup of the journal inode */
511         /* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
512 /*150*/ __le32  s_blocks_count_hi;      /* Blocks count */
513         __le32  s_r_blocks_count_hi;    /* Reserved blocks count */
514         __le32  s_free_blocks_count_hi; /* Free blocks count */
515         __u32   s_reserved[169];        /* Padding to the end of the block */
516 };
517
518 #ifdef __KERNEL__
519 static inline struct ext4_sb_info * EXT4_SB(struct super_block *sb)
520 {
521         return sb->s_fs_info;
522 }
523 static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
524 {
525         return container_of(inode, struct ext4_inode_info, vfs_inode);
526 }
527
528 static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
529 {
530         return ino == EXT4_ROOT_INO ||
531                 ino == EXT4_JOURNAL_INO ||
532                 ino == EXT4_RESIZE_INO ||
533                 (ino >= EXT4_FIRST_INO(sb) &&
534                  ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
535 }
536 #else
537 /* Assume that user mode programs are passing in an ext4fs superblock, not
538  * a kernel struct super_block.  This will allow us to call the feature-test
539  * macros from user land. */
540 #define EXT4_SB(sb)     (sb)
541 #endif
542
543 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
544
545 /*
546  * Codes for operating systems
547  */
548 #define EXT4_OS_LINUX           0
549 #define EXT4_OS_HURD            1
550 #define EXT4_OS_MASIX           2
551 #define EXT4_OS_FREEBSD         3
552 #define EXT4_OS_LITES           4
553
554 /*
555  * Revision levels
556  */
557 #define EXT4_GOOD_OLD_REV       0       /* The good old (original) format */
558 #define EXT4_DYNAMIC_REV        1       /* V2 format w/ dynamic inode sizes */
559
560 #define EXT4_CURRENT_REV        EXT4_GOOD_OLD_REV
561 #define EXT4_MAX_SUPP_REV       EXT4_DYNAMIC_REV
562
563 #define EXT4_GOOD_OLD_INODE_SIZE 128
564
565 /*
566  * Feature set definitions
567  */
568
569 #define EXT4_HAS_COMPAT_FEATURE(sb,mask)                        \
570         ( EXT4_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask) )
571 #define EXT4_HAS_RO_COMPAT_FEATURE(sb,mask)                     \
572         ( EXT4_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask) )
573 #define EXT4_HAS_INCOMPAT_FEATURE(sb,mask)                      \
574         ( EXT4_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask) )
575 #define EXT4_SET_COMPAT_FEATURE(sb,mask)                        \
576         EXT4_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
577 #define EXT4_SET_RO_COMPAT_FEATURE(sb,mask)                     \
578         EXT4_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
579 #define EXT4_SET_INCOMPAT_FEATURE(sb,mask)                      \
580         EXT4_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
581 #define EXT4_CLEAR_COMPAT_FEATURE(sb,mask)                      \
582         EXT4_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
583 #define EXT4_CLEAR_RO_COMPAT_FEATURE(sb,mask)                   \
584         EXT4_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
585 #define EXT4_CLEAR_INCOMPAT_FEATURE(sb,mask)                    \
586         EXT4_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
587
588 #define EXT4_FEATURE_COMPAT_DIR_PREALLOC        0x0001
589 #define EXT4_FEATURE_COMPAT_IMAGIC_INODES       0x0002
590 #define EXT4_FEATURE_COMPAT_HAS_JOURNAL         0x0004
591 #define EXT4_FEATURE_COMPAT_EXT_ATTR            0x0008
592 #define EXT4_FEATURE_COMPAT_RESIZE_INODE        0x0010
593 #define EXT4_FEATURE_COMPAT_DIR_INDEX           0x0020
594
595 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER     0x0001
596 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE       0x0002
597 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR        0x0004
598
599 #define EXT4_FEATURE_INCOMPAT_COMPRESSION       0x0001
600 #define EXT4_FEATURE_INCOMPAT_FILETYPE          0x0002
601 #define EXT4_FEATURE_INCOMPAT_RECOVER           0x0004 /* Needs recovery */
602 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV       0x0008 /* Journal device */
603 #define EXT4_FEATURE_INCOMPAT_META_BG           0x0010
604 #define EXT4_FEATURE_INCOMPAT_EXTENTS           0x0040 /* extents support */
605 #define EXT4_FEATURE_INCOMPAT_64BIT             0x0080
606
607 #define EXT4_FEATURE_COMPAT_SUPP        EXT2_FEATURE_COMPAT_EXT_ATTR
608 #define EXT4_FEATURE_INCOMPAT_SUPP      (EXT4_FEATURE_INCOMPAT_FILETYPE| \
609                                          EXT4_FEATURE_INCOMPAT_RECOVER| \
610                                          EXT4_FEATURE_INCOMPAT_META_BG| \
611                                          EXT4_FEATURE_INCOMPAT_EXTENTS| \
612                                          EXT4_FEATURE_INCOMPAT_64BIT)
613 #define EXT4_FEATURE_RO_COMPAT_SUPP     (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
614                                          EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
615                                          EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
616
617 /*
618  * Default values for user and/or group using reserved blocks
619  */
620 #define EXT4_DEF_RESUID         0
621 #define EXT4_DEF_RESGID         0
622
623 /*
624  * Default mount options
625  */
626 #define EXT4_DEFM_DEBUG         0x0001
627 #define EXT4_DEFM_BSDGROUPS     0x0002
628 #define EXT4_DEFM_XATTR_USER    0x0004
629 #define EXT4_DEFM_ACL           0x0008
630 #define EXT4_DEFM_UID16         0x0010
631 #define EXT4_DEFM_JMODE         0x0060
632 #define EXT4_DEFM_JMODE_DATA    0x0020
633 #define EXT4_DEFM_JMODE_ORDERED 0x0040
634 #define EXT4_DEFM_JMODE_WBACK   0x0060
635
636 /*
637  * Structure of a directory entry
638  */
639 #define EXT4_NAME_LEN 255
640
641 struct ext4_dir_entry {
642         __le32  inode;                  /* Inode number */
643         __le16  rec_len;                /* Directory entry length */
644         __le16  name_len;               /* Name length */
645         char    name[EXT4_NAME_LEN];    /* File name */
646 };
647
648 /*
649  * The new version of the directory entry.  Since EXT4 structures are
650  * stored in intel byte order, and the name_len field could never be
651  * bigger than 255 chars, it's safe to reclaim the extra byte for the
652  * file_type field.
653  */
654 struct ext4_dir_entry_2 {
655         __le32  inode;                  /* Inode number */
656         __le16  rec_len;                /* Directory entry length */
657         __u8    name_len;               /* Name length */
658         __u8    file_type;
659         char    name[EXT4_NAME_LEN];    /* File name */
660 };
661
662 /*
663  * Ext4 directory file types.  Only the low 3 bits are used.  The
664  * other bits are reserved for now.
665  */
666 #define EXT4_FT_UNKNOWN         0
667 #define EXT4_FT_REG_FILE        1
668 #define EXT4_FT_DIR             2
669 #define EXT4_FT_CHRDEV          3
670 #define EXT4_FT_BLKDEV          4
671 #define EXT4_FT_FIFO            5
672 #define EXT4_FT_SOCK            6
673 #define EXT4_FT_SYMLINK         7
674
675 #define EXT4_FT_MAX             8
676
677 /*
678  * EXT4_DIR_PAD defines the directory entries boundaries
679  *
680  * NOTE: It must be a multiple of 4
681  */
682 #define EXT4_DIR_PAD                    4
683 #define EXT4_DIR_ROUND                  (EXT4_DIR_PAD - 1)
684 #define EXT4_DIR_REC_LEN(name_len)      (((name_len) + 8 + EXT4_DIR_ROUND) & \
685                                          ~EXT4_DIR_ROUND)
686 /*
687  * Hash Tree Directory indexing
688  * (c) Daniel Phillips, 2001
689  */
690
691 #ifdef CONFIG_EXT4_INDEX
692   #define is_dx(dir) (EXT4_HAS_COMPAT_FEATURE(dir->i_sb, \
693                                               EXT4_FEATURE_COMPAT_DIR_INDEX) && \
694                       (EXT4_I(dir)->i_flags & EXT4_INDEX_FL))
695 #define EXT4_DIR_LINK_MAX(dir) (!is_dx(dir) && (dir)->i_nlink >= EXT4_LINK_MAX)
696 #define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
697 #else
698   #define is_dx(dir) 0
699 #define EXT4_DIR_LINK_MAX(dir) ((dir)->i_nlink >= EXT4_LINK_MAX)
700 #define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2)
701 #endif
702
703 /* Legal values for the dx_root hash_version field: */
704
705 #define DX_HASH_LEGACY          0
706 #define DX_HASH_HALF_MD4        1
707 #define DX_HASH_TEA             2
708
709 #ifdef __KERNEL__
710
711 /* hash info structure used by the directory hash */
712 struct dx_hash_info
713 {
714         u32             hash;
715         u32             minor_hash;
716         int             hash_version;
717         u32             *seed;
718 };
719
720 #define EXT4_HTREE_EOF  0x7fffffff
721
722 /*
723  * Control parameters used by ext4_htree_next_block
724  */
725 #define HASH_NB_ALWAYS          1
726
727
728 /*
729  * Describe an inode's exact location on disk and in memory
730  */
731 struct ext4_iloc
732 {
733         struct buffer_head *bh;
734         unsigned long offset;
735         unsigned long block_group;
736 };
737
738 static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
739 {
740         return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
741 }
742
743 /*
744  * This structure is stuffed into the struct file's private_data field
745  * for directories.  It is where we put information so that we can do
746  * readdir operations in hash tree order.
747  */
748 struct dir_private_info {
749         struct rb_root  root;
750         struct rb_node  *curr_node;
751         struct fname    *extra_fname;
752         loff_t          last_pos;
753         __u32           curr_hash;
754         __u32           curr_minor_hash;
755         __u32           next_hash;
756 };
757
758 /* calculate the first block number of the group */
759 static inline ext4_fsblk_t
760 ext4_group_first_block_no(struct super_block *sb, unsigned long group_no)
761 {
762         return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
763                 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
764 }
765
766 /*
767  * Special error return code only used by dx_probe() and its callers.
768  */
769 #define ERR_BAD_DX_DIR  -75000
770
771 /*
772  * This function calculate the block group number and offset,
773  * given a block number
774  */
775
776 static inline void ext4_get_group_no_and_offset(struct super_block * sb,
777                                 ext4_fsblk_t blocknr, unsigned long* blockgrpp,
778                                 ext4_grpblk_t *offsetp)
779 {
780         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
781         ext4_grpblk_t offset;
782
783         blocknr = blocknr - le32_to_cpu(es->s_first_data_block);
784         offset = sector_div(blocknr, EXT4_BLOCKS_PER_GROUP(sb));
785         if (offsetp)
786                 *offsetp = offset;
787         if (blockgrpp)
788                 *blockgrpp = blocknr;
789
790 }
791
792 /*
793  * Function prototypes
794  */
795
796 /*
797  * Ok, these declarations are also in <linux/kernel.h> but none of the
798  * ext4 source programs needs to include it so they are duplicated here.
799  */
800 # define NORET_TYPE    /**/
801 # define ATTRIB_NORET  __attribute__((noreturn))
802 # define NORET_AND     noreturn,
803
804 /* balloc.c */
805 extern unsigned int ext4_block_group(struct super_block *sb,
806                         ext4_fsblk_t blocknr);
807 extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
808                         ext4_fsblk_t blocknr);
809 extern int ext4_bg_has_super(struct super_block *sb, int group);
810 extern unsigned long ext4_bg_num_gdb(struct super_block *sb, int group);
811 extern ext4_fsblk_t ext4_new_block (handle_t *handle, struct inode *inode,
812                         ext4_fsblk_t goal, int *errp);
813 extern ext4_fsblk_t ext4_new_blocks (handle_t *handle, struct inode *inode,
814                         ext4_fsblk_t goal, unsigned long *count, int *errp);
815 extern void ext4_free_blocks (handle_t *handle, struct inode *inode,
816                         ext4_fsblk_t block, unsigned long count);
817 extern void ext4_free_blocks_sb (handle_t *handle, struct super_block *sb,
818                                  ext4_fsblk_t block, unsigned long count,
819                                 unsigned long *pdquot_freed_blocks);
820 extern ext4_fsblk_t ext4_count_free_blocks (struct super_block *);
821 extern void ext4_check_blocks_bitmap (struct super_block *);
822 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
823                                                     unsigned int block_group,
824                                                     struct buffer_head ** bh);
825 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
826 extern void ext4_init_block_alloc_info(struct inode *);
827 extern void ext4_rsv_window_add(struct super_block *sb, struct ext4_reserve_window_node *rsv);
828
829 /* dir.c */
830 extern int ext4_check_dir_entry(const char *, struct inode *,
831                                 struct ext4_dir_entry_2 *,
832                                 struct buffer_head *, unsigned long);
833 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
834                                     __u32 minor_hash,
835                                     struct ext4_dir_entry_2 *dirent);
836 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
837
838 /* fsync.c */
839 extern int ext4_sync_file (struct file *, struct dentry *, int);
840
841 /* hash.c */
842 extern int ext4fs_dirhash(const char *name, int len, struct
843                           dx_hash_info *hinfo);
844
845 /* ialloc.c */
846 extern struct inode * ext4_new_inode (handle_t *, struct inode *, int);
847 extern void ext4_free_inode (handle_t *, struct inode *);
848 extern struct inode * ext4_orphan_get (struct super_block *, unsigned long);
849 extern unsigned long ext4_count_free_inodes (struct super_block *);
850 extern unsigned long ext4_count_dirs (struct super_block *);
851 extern void ext4_check_inodes_bitmap (struct super_block *);
852 extern unsigned long ext4_count_free (struct buffer_head *, unsigned);
853
854
855 /* inode.c */
856 int ext4_forget(handle_t *handle, int is_metadata, struct inode *inode,
857                 struct buffer_head *bh, ext4_fsblk_t blocknr);
858 struct buffer_head * ext4_getblk (handle_t *, struct inode *, long, int, int *);
859 struct buffer_head * ext4_bread (handle_t *, struct inode *, int, int, int *);
860 int ext4_get_blocks_handle(handle_t *handle, struct inode *inode,
861         sector_t iblock, unsigned long maxblocks, struct buffer_head *bh_result,
862         int create, int extend_disksize);
863
864 extern void ext4_read_inode (struct inode *);
865 extern int  ext4_write_inode (struct inode *, int);
866 extern int  ext4_setattr (struct dentry *, struct iattr *);
867 extern void ext4_delete_inode (struct inode *);
868 extern int  ext4_sync_inode (handle_t *, struct inode *);
869 extern void ext4_discard_reservation (struct inode *);
870 extern void ext4_dirty_inode(struct inode *);
871 extern int ext4_change_inode_journal_flag(struct inode *, int);
872 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
873 extern void ext4_truncate (struct inode *);
874 extern void ext4_set_inode_flags(struct inode *);
875 extern void ext4_set_aops(struct inode *inode);
876 extern int ext4_writepage_trans_blocks(struct inode *);
877 extern int ext4_block_truncate_page(handle_t *handle, struct page *page,
878                 struct address_space *mapping, loff_t from);
879
880 /* ioctl.c */
881 extern int ext4_ioctl (struct inode *, struct file *, unsigned int,
882                        unsigned long);
883 extern long ext4_compat_ioctl (struct file *, unsigned int, unsigned long);
884
885 /* namei.c */
886 extern int ext4_orphan_add(handle_t *, struct inode *);
887 extern int ext4_orphan_del(handle_t *, struct inode *);
888 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
889                                 __u32 start_minor_hash, __u32 *next_hash);
890
891 /* resize.c */
892 extern int ext4_group_add(struct super_block *sb,
893                                 struct ext4_new_group_data *input);
894 extern int ext4_group_extend(struct super_block *sb,
895                                 struct ext4_super_block *es,
896                                 ext4_fsblk_t n_blocks_count);
897
898 /* super.c */
899 extern void ext4_error (struct super_block *, const char *, const char *, ...)
900         __attribute__ ((format (printf, 3, 4)));
901 extern void __ext4_std_error (struct super_block *, const char *, int);
902 extern void ext4_abort (struct super_block *, const char *, const char *, ...)
903         __attribute__ ((format (printf, 3, 4)));
904 extern void ext4_warning (struct super_block *, const char *, const char *, ...)
905         __attribute__ ((format (printf, 3, 4)));
906 extern void ext4_update_dynamic_rev (struct super_block *sb);
907 extern ext4_fsblk_t ext4_block_bitmap(struct ext4_group_desc *bg);
908 extern ext4_fsblk_t ext4_inode_bitmap(struct ext4_group_desc *bg);
909 extern ext4_fsblk_t ext4_inode_table(struct ext4_group_desc *bg);
910 extern void ext4_block_bitmap_set(struct ext4_group_desc *bg, ext4_fsblk_t blk);
911 extern void ext4_inode_bitmap_set(struct ext4_group_desc *bg, ext4_fsblk_t blk);
912 extern void ext4_inode_table_set(struct ext4_group_desc *bg, ext4_fsblk_t blk);
913
914 static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
915 {
916         return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |
917                 le32_to_cpu(es->s_blocks_count);
918 }
919
920 static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
921 {
922         return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |
923                 le32_to_cpu(es->s_r_blocks_count);
924 }
925
926 static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
927 {
928         return ((ext4_fsblk_t)le32_to_cpu(es->s_free_blocks_count_hi) << 32) |
929                 le32_to_cpu(es->s_free_blocks_count);
930 }
931
932 static inline void ext4_blocks_count_set(struct ext4_super_block *es,
933                                          ext4_fsblk_t blk)
934 {
935         es->s_blocks_count = cpu_to_le32((u32)blk);
936         es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
937 }
938
939 static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
940                                               ext4_fsblk_t blk)
941 {
942         es->s_free_blocks_count = cpu_to_le32((u32)blk);
943         es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
944 }
945
946 static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
947                                            ext4_fsblk_t blk)
948 {
949         es->s_r_blocks_count = cpu_to_le32((u32)blk);
950         es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
951 }
952
953
954
955 #define ext4_std_error(sb, errno)                               \
956 do {                                                            \
957         if ((errno))                                            \
958                 __ext4_std_error((sb), __FUNCTION__, (errno));  \
959 } while (0)
960
961 /*
962  * Inodes and files operations
963  */
964
965 /* dir.c */
966 extern const struct file_operations ext4_dir_operations;
967
968 /* file.c */
969 extern struct inode_operations ext4_file_inode_operations;
970 extern const struct file_operations ext4_file_operations;
971
972 /* namei.c */
973 extern struct inode_operations ext4_dir_inode_operations;
974 extern struct inode_operations ext4_special_inode_operations;
975
976 /* symlink.c */
977 extern struct inode_operations ext4_symlink_inode_operations;
978 extern struct inode_operations ext4_fast_symlink_inode_operations;
979
980 /* extents.c */
981 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
982 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
983 extern int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
984                         ext4_fsblk_t iblock,
985                         unsigned long max_blocks, struct buffer_head *bh_result,
986                         int create, int extend_disksize);
987 extern void ext4_ext_truncate(struct inode *, struct page *);
988 extern void ext4_ext_init(struct super_block *);
989 extern void ext4_ext_release(struct super_block *);
990 static inline int
991 ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block,
992                         unsigned long max_blocks, struct buffer_head *bh,
993                         int create, int extend_disksize)
994 {
995         if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)
996                 return ext4_ext_get_blocks(handle, inode, block, max_blocks,
997                                         bh, create, extend_disksize);
998         return ext4_get_blocks_handle(handle, inode, block, max_blocks, bh,
999                                         create, extend_disksize);
1000 }
1001
1002
1003 #endif  /* __KERNEL__ */
1004
1005 #endif  /* _LINUX_EXT4_FS_H */