Add sg helpers for iterating over a scatterlist table
[linux-2.6] / include / linux / ext2_fs.h
1 /*
2  *  linux/include/linux/ext2_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_EXT2_FS_H
17 #define _LINUX_EXT2_FS_H
18
19 #include <linux/types.h>
20 #include <linux/magic.h>
21
22 /*
23  * The second extended filesystem constants/structures
24  */
25
26 /*
27  * Define EXT2FS_DEBUG to produce debug messages
28  */
29 #undef EXT2FS_DEBUG
30
31 /*
32  * Define EXT2_PREALLOCATE to preallocate data blocks for expanding files
33  */
34 #define EXT2_PREALLOCATE
35 #define EXT2_DEFAULT_PREALLOC_BLOCKS    8
36
37 /*
38  * The second extended file system version
39  */
40 #define EXT2FS_DATE             "95/08/09"
41 #define EXT2FS_VERSION          "0.5b"
42
43 /*
44  * Debug code
45  */
46 #ifdef EXT2FS_DEBUG
47 #       define ext2_debug(f, a...)      { \
48                                         printk ("EXT2-fs DEBUG (%s, %d): %s:", \
49                                                 __FILE__, __LINE__, __FUNCTION__); \
50                                         printk (f, ## a); \
51                                         }
52 #else
53 #       define ext2_debug(f, a...)      /**/
54 #endif
55
56 /*
57  * Special inode numbers
58  */
59 #define EXT2_BAD_INO             1      /* Bad blocks inode */
60 #define EXT2_ROOT_INO            2      /* Root inode */
61 #define EXT2_BOOT_LOADER_INO     5      /* Boot loader inode */
62 #define EXT2_UNDEL_DIR_INO       6      /* Undelete directory inode */
63
64 /* First non-reserved inode for old ext2 filesystems */
65 #define EXT2_GOOD_OLD_FIRST_INO 11
66
67 #ifdef __KERNEL__
68 #include <linux/ext2_fs_sb.h>
69 static inline struct ext2_sb_info *EXT2_SB(struct super_block *sb)
70 {
71         return sb->s_fs_info;
72 }
73 #else
74 /* Assume that user mode programs are passing in an ext2fs superblock, not
75  * a kernel struct super_block.  This will allow us to call the feature-test
76  * macros from user land. */
77 #define EXT2_SB(sb)     (sb)
78 #endif
79
80 /*
81  * Maximal count of links to a file
82  */
83 #define EXT2_LINK_MAX           32000
84
85 /*
86  * Macro-instructions used to manage several block sizes
87  */
88 #define EXT2_MIN_BLOCK_SIZE             1024
89 #define EXT2_MAX_BLOCK_SIZE             4096
90 #define EXT2_MIN_BLOCK_LOG_SIZE           10
91 #ifdef __KERNEL__
92 # define EXT2_BLOCK_SIZE(s)             ((s)->s_blocksize)
93 #else
94 # define EXT2_BLOCK_SIZE(s)             (EXT2_MIN_BLOCK_SIZE << (s)->s_log_block_size)
95 #endif
96 #define EXT2_ADDR_PER_BLOCK(s)          (EXT2_BLOCK_SIZE(s) / sizeof (__u32))
97 #ifdef __KERNEL__
98 # define EXT2_BLOCK_SIZE_BITS(s)        ((s)->s_blocksize_bits)
99 #else
100 # define EXT2_BLOCK_SIZE_BITS(s)        ((s)->s_log_block_size + 10)
101 #endif
102 #ifdef __KERNEL__
103 #define EXT2_ADDR_PER_BLOCK_BITS(s)     (EXT2_SB(s)->s_addr_per_block_bits)
104 #define EXT2_INODE_SIZE(s)              (EXT2_SB(s)->s_inode_size)
105 #define EXT2_FIRST_INO(s)               (EXT2_SB(s)->s_first_ino)
106 #else
107 #define EXT2_INODE_SIZE(s)      (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
108                                  EXT2_GOOD_OLD_INODE_SIZE : \
109                                  (s)->s_inode_size)
110 #define EXT2_FIRST_INO(s)       (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
111                                  EXT2_GOOD_OLD_FIRST_INO : \
112                                  (s)->s_first_ino)
113 #endif
114
115 /*
116  * Macro-instructions used to manage fragments
117  */
118 #define EXT2_MIN_FRAG_SIZE              1024
119 #define EXT2_MAX_FRAG_SIZE              4096
120 #define EXT2_MIN_FRAG_LOG_SIZE            10
121 #ifdef __KERNEL__
122 # define EXT2_FRAG_SIZE(s)              (EXT2_SB(s)->s_frag_size)
123 # define EXT2_FRAGS_PER_BLOCK(s)        (EXT2_SB(s)->s_frags_per_block)
124 #else
125 # define EXT2_FRAG_SIZE(s)              (EXT2_MIN_FRAG_SIZE << (s)->s_log_frag_size)
126 # define EXT2_FRAGS_PER_BLOCK(s)        (EXT2_BLOCK_SIZE(s) / EXT2_FRAG_SIZE(s))
127 #endif
128
129 /*
130  * Structure of a blocks group descriptor
131  */
132 struct ext2_group_desc
133 {
134         __le32  bg_block_bitmap;                /* Blocks bitmap block */
135         __le32  bg_inode_bitmap;                /* Inodes bitmap block */
136         __le32  bg_inode_table;         /* Inodes table block */
137         __le16  bg_free_blocks_count;   /* Free blocks count */
138         __le16  bg_free_inodes_count;   /* Free inodes count */
139         __le16  bg_used_dirs_count;     /* Directories count */
140         __le16  bg_pad;
141         __le32  bg_reserved[3];
142 };
143
144 /*
145  * Macro-instructions used to manage group descriptors
146  */
147 #ifdef __KERNEL__
148 # define EXT2_BLOCKS_PER_GROUP(s)       (EXT2_SB(s)->s_blocks_per_group)
149 # define EXT2_DESC_PER_BLOCK(s)         (EXT2_SB(s)->s_desc_per_block)
150 # define EXT2_INODES_PER_GROUP(s)       (EXT2_SB(s)->s_inodes_per_group)
151 # define EXT2_DESC_PER_BLOCK_BITS(s)    (EXT2_SB(s)->s_desc_per_block_bits)
152 #else
153 # define EXT2_BLOCKS_PER_GROUP(s)       ((s)->s_blocks_per_group)
154 # define EXT2_DESC_PER_BLOCK(s)         (EXT2_BLOCK_SIZE(s) / sizeof (struct ext2_group_desc))
155 # define EXT2_INODES_PER_GROUP(s)       ((s)->s_inodes_per_group)
156 #endif
157
158 /*
159  * Constants relative to the data blocks
160  */
161 #define EXT2_NDIR_BLOCKS                12
162 #define EXT2_IND_BLOCK                  EXT2_NDIR_BLOCKS
163 #define EXT2_DIND_BLOCK                 (EXT2_IND_BLOCK + 1)
164 #define EXT2_TIND_BLOCK                 (EXT2_DIND_BLOCK + 1)
165 #define EXT2_N_BLOCKS                   (EXT2_TIND_BLOCK + 1)
166
167 /*
168  * Inode flags (GETFLAGS/SETFLAGS)
169  */
170 #define EXT2_SECRM_FL                   FS_SECRM_FL     /* Secure deletion */
171 #define EXT2_UNRM_FL                    FS_UNRM_FL      /* Undelete */
172 #define EXT2_COMPR_FL                   FS_COMPR_FL     /* Compress file */
173 #define EXT2_SYNC_FL                    FS_SYNC_FL      /* Synchronous updates */
174 #define EXT2_IMMUTABLE_FL               FS_IMMUTABLE_FL /* Immutable file */
175 #define EXT2_APPEND_FL                  FS_APPEND_FL    /* writes to file may only append */
176 #define EXT2_NODUMP_FL                  FS_NODUMP_FL    /* do not dump file */
177 #define EXT2_NOATIME_FL                 FS_NOATIME_FL   /* do not update atime */
178 /* Reserved for compression usage... */
179 #define EXT2_DIRTY_FL                   FS_DIRTY_FL
180 #define EXT2_COMPRBLK_FL                FS_COMPRBLK_FL  /* One or more compressed clusters */
181 #define EXT2_NOCOMP_FL                  FS_NOCOMP_FL    /* Don't compress */
182 #define EXT2_ECOMPR_FL                  FS_ECOMPR_FL    /* Compression error */
183 /* End compression flags --- maybe not all used */      
184 #define EXT2_BTREE_FL                   FS_BTREE_FL     /* btree format dir */
185 #define EXT2_INDEX_FL                   FS_INDEX_FL     /* hash-indexed directory */
186 #define EXT2_IMAGIC_FL                  FS_IMAGIC_FL    /* AFS directory */
187 #define EXT2_JOURNAL_DATA_FL            FS_JOURNAL_DATA_FL /* Reserved for ext3 */
188 #define EXT2_NOTAIL_FL                  FS_NOTAIL_FL    /* file tail should not be merged */
189 #define EXT2_DIRSYNC_FL                 FS_DIRSYNC_FL   /* dirsync behaviour (directories only) */
190 #define EXT2_TOPDIR_FL                  FS_TOPDIR_FL    /* Top of directory hierarchies*/
191 #define EXT2_RESERVED_FL                FS_RESERVED_FL  /* reserved for ext2 lib */
192
193 #define EXT2_FL_USER_VISIBLE            FS_FL_USER_VISIBLE      /* User visible flags */
194 #define EXT2_FL_USER_MODIFIABLE         FS_FL_USER_MODIFIABLE   /* User modifiable flags */
195
196 /*
197  * ioctl commands
198  */
199 #define EXT2_IOC_GETFLAGS               FS_IOC_GETFLAGS
200 #define EXT2_IOC_SETFLAGS               FS_IOC_SETFLAGS
201 #define EXT2_IOC_GETVERSION             FS_IOC_GETVERSION
202 #define EXT2_IOC_SETVERSION             FS_IOC_SETVERSION
203
204 /*
205  * ioctl commands in 32 bit emulation
206  */
207 #define EXT2_IOC32_GETFLAGS             FS_IOC32_GETFLAGS
208 #define EXT2_IOC32_SETFLAGS             FS_IOC32_SETFLAGS
209 #define EXT2_IOC32_GETVERSION           FS_IOC32_GETVERSION
210 #define EXT2_IOC32_SETVERSION           FS_IOC32_SETVERSION
211
212 /*
213  * Structure of an inode on the disk
214  */
215 struct ext2_inode {
216         __le16  i_mode;         /* File mode */
217         __le16  i_uid;          /* Low 16 bits of Owner Uid */
218         __le32  i_size;         /* Size in bytes */
219         __le32  i_atime;        /* Access time */
220         __le32  i_ctime;        /* Creation time */
221         __le32  i_mtime;        /* Modification time */
222         __le32  i_dtime;        /* Deletion Time */
223         __le16  i_gid;          /* Low 16 bits of Group Id */
224         __le16  i_links_count;  /* Links count */
225         __le32  i_blocks;       /* Blocks count */
226         __le32  i_flags;        /* File flags */
227         union {
228                 struct {
229                         __le32  l_i_reserved1;
230                 } linux1;
231                 struct {
232                         __le32  h_i_translator;
233                 } hurd1;
234                 struct {
235                         __le32  m_i_reserved1;
236                 } masix1;
237         } osd1;                         /* OS dependent 1 */
238         __le32  i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
239         __le32  i_generation;   /* File version (for NFS) */
240         __le32  i_file_acl;     /* File ACL */
241         __le32  i_dir_acl;      /* Directory ACL */
242         __le32  i_faddr;        /* Fragment address */
243         union {
244                 struct {
245                         __u8    l_i_frag;       /* Fragment number */
246                         __u8    l_i_fsize;      /* Fragment size */
247                         __u16   i_pad1;
248                         __le16  l_i_uid_high;   /* these 2 fields    */
249                         __le16  l_i_gid_high;   /* were reserved2[0] */
250                         __u32   l_i_reserved2;
251                 } linux2;
252                 struct {
253                         __u8    h_i_frag;       /* Fragment number */
254                         __u8    h_i_fsize;      /* Fragment size */
255                         __le16  h_i_mode_high;
256                         __le16  h_i_uid_high;
257                         __le16  h_i_gid_high;
258                         __le32  h_i_author;
259                 } hurd2;
260                 struct {
261                         __u8    m_i_frag;       /* Fragment number */
262                         __u8    m_i_fsize;      /* Fragment size */
263                         __u16   m_pad1;
264                         __u32   m_i_reserved2[2];
265                 } masix2;
266         } osd2;                         /* OS dependent 2 */
267 };
268
269 #define i_size_high     i_dir_acl
270
271 #if defined(__KERNEL__) || defined(__linux__)
272 #define i_reserved1     osd1.linux1.l_i_reserved1
273 #define i_frag          osd2.linux2.l_i_frag
274 #define i_fsize         osd2.linux2.l_i_fsize
275 #define i_uid_low       i_uid
276 #define i_gid_low       i_gid
277 #define i_uid_high      osd2.linux2.l_i_uid_high
278 #define i_gid_high      osd2.linux2.l_i_gid_high
279 #define i_reserved2     osd2.linux2.l_i_reserved2
280 #endif
281
282 #ifdef  __hurd__
283 #define i_translator    osd1.hurd1.h_i_translator
284 #define i_frag          osd2.hurd2.h_i_frag;
285 #define i_fsize         osd2.hurd2.h_i_fsize;
286 #define i_uid_high      osd2.hurd2.h_i_uid_high
287 #define i_gid_high      osd2.hurd2.h_i_gid_high
288 #define i_author        osd2.hurd2.h_i_author
289 #endif
290
291 #ifdef  __masix__
292 #define i_reserved1     osd1.masix1.m_i_reserved1
293 #define i_frag          osd2.masix2.m_i_frag
294 #define i_fsize         osd2.masix2.m_i_fsize
295 #define i_reserved2     osd2.masix2.m_i_reserved2
296 #endif
297
298 /*
299  * File system states
300  */
301 #define EXT2_VALID_FS                   0x0001  /* Unmounted cleanly */
302 #define EXT2_ERROR_FS                   0x0002  /* Errors detected */
303
304 /*
305  * Mount flags
306  */
307 #define EXT2_MOUNT_CHECK                0x000001  /* Do mount-time checks */
308 #define EXT2_MOUNT_OLDALLOC             0x000002  /* Don't use the new Orlov allocator */
309 #define EXT2_MOUNT_GRPID                0x000004  /* Create files with directory's group */
310 #define EXT2_MOUNT_DEBUG                0x000008  /* Some debugging messages */
311 #define EXT2_MOUNT_ERRORS_CONT          0x000010  /* Continue on errors */
312 #define EXT2_MOUNT_ERRORS_RO            0x000020  /* Remount fs ro on errors */
313 #define EXT2_MOUNT_ERRORS_PANIC         0x000040  /* Panic on errors */
314 #define EXT2_MOUNT_MINIX_DF             0x000080  /* Mimics the Minix statfs */
315 #define EXT2_MOUNT_NOBH                 0x000100  /* No buffer_heads */
316 #define EXT2_MOUNT_NO_UID32             0x000200  /* Disable 32-bit UIDs */
317 #define EXT2_MOUNT_XATTR_USER           0x004000  /* Extended user attributes */
318 #define EXT2_MOUNT_POSIX_ACL            0x008000  /* POSIX Access Control Lists */
319 #define EXT2_MOUNT_XIP                  0x010000  /* Execute in place */
320 #define EXT2_MOUNT_USRQUOTA             0x020000 /* user quota */
321 #define EXT2_MOUNT_GRPQUOTA             0x040000 /* group quota */
322
323
324 #define clear_opt(o, opt)               o &= ~EXT2_MOUNT_##opt
325 #define set_opt(o, opt)                 o |= EXT2_MOUNT_##opt
326 #define test_opt(sb, opt)               (EXT2_SB(sb)->s_mount_opt & \
327                                          EXT2_MOUNT_##opt)
328 /*
329  * Maximal mount counts between two filesystem checks
330  */
331 #define EXT2_DFL_MAX_MNT_COUNT          20      /* Allow 20 mounts */
332 #define EXT2_DFL_CHECKINTERVAL          0       /* Don't use interval check */
333
334 /*
335  * Behaviour when detecting errors
336  */
337 #define EXT2_ERRORS_CONTINUE            1       /* Continue execution */
338 #define EXT2_ERRORS_RO                  2       /* Remount fs read-only */
339 #define EXT2_ERRORS_PANIC               3       /* Panic */
340 #define EXT2_ERRORS_DEFAULT             EXT2_ERRORS_CONTINUE
341
342 /*
343  * Structure of the super block
344  */
345 struct ext2_super_block {
346         __le32  s_inodes_count;         /* Inodes count */
347         __le32  s_blocks_count;         /* Blocks count */
348         __le32  s_r_blocks_count;       /* Reserved blocks count */
349         __le32  s_free_blocks_count;    /* Free blocks count */
350         __le32  s_free_inodes_count;    /* Free inodes count */
351         __le32  s_first_data_block;     /* First Data Block */
352         __le32  s_log_block_size;       /* Block size */
353         __le32  s_log_frag_size;        /* Fragment size */
354         __le32  s_blocks_per_group;     /* # Blocks per group */
355         __le32  s_frags_per_group;      /* # Fragments per group */
356         __le32  s_inodes_per_group;     /* # Inodes per group */
357         __le32  s_mtime;                /* Mount time */
358         __le32  s_wtime;                /* Write time */
359         __le16  s_mnt_count;            /* Mount count */
360         __le16  s_max_mnt_count;        /* Maximal mount count */
361         __le16  s_magic;                /* Magic signature */
362         __le16  s_state;                /* File system state */
363         __le16  s_errors;               /* Behaviour when detecting errors */
364         __le16  s_minor_rev_level;      /* minor revision level */
365         __le32  s_lastcheck;            /* time of last check */
366         __le32  s_checkinterval;        /* max. time between checks */
367         __le32  s_creator_os;           /* OS */
368         __le32  s_rev_level;            /* Revision level */
369         __le16  s_def_resuid;           /* Default uid for reserved blocks */
370         __le16  s_def_resgid;           /* Default gid for reserved blocks */
371         /*
372          * These fields are for EXT2_DYNAMIC_REV superblocks only.
373          *
374          * Note: the difference between the compatible feature set and
375          * the incompatible feature set is that if there is a bit set
376          * in the incompatible feature set that the kernel doesn't
377          * know about, it should refuse to mount the filesystem.
378          * 
379          * e2fsck's requirements are more strict; if it doesn't know
380          * about a feature in either the compatible or incompatible
381          * feature set, it must abort and not try to meddle with
382          * things it doesn't understand...
383          */
384         __le32  s_first_ino;            /* First non-reserved inode */
385         __le16   s_inode_size;          /* size of inode structure */
386         __le16  s_block_group_nr;       /* block group # of this superblock */
387         __le32  s_feature_compat;       /* compatible feature set */
388         __le32  s_feature_incompat;     /* incompatible feature set */
389         __le32  s_feature_ro_compat;    /* readonly-compatible feature set */
390         __u8    s_uuid[16];             /* 128-bit uuid for volume */
391         char    s_volume_name[16];      /* volume name */
392         char    s_last_mounted[64];     /* directory where last mounted */
393         __le32  s_algorithm_usage_bitmap; /* For compression */
394         /*
395          * Performance hints.  Directory preallocation should only
396          * happen if the EXT2_COMPAT_PREALLOC flag is on.
397          */
398         __u8    s_prealloc_blocks;      /* Nr of blocks to try to preallocate*/
399         __u8    s_prealloc_dir_blocks;  /* Nr to preallocate for dirs */
400         __u16   s_padding1;
401         /*
402          * Journaling support valid if EXT3_FEATURE_COMPAT_HAS_JOURNAL set.
403          */
404         __u8    s_journal_uuid[16];     /* uuid of journal superblock */
405         __u32   s_journal_inum;         /* inode number of journal file */
406         __u32   s_journal_dev;          /* device number of journal file */
407         __u32   s_last_orphan;          /* start of list of inodes to delete */
408         __u32   s_hash_seed[4];         /* HTREE hash seed */
409         __u8    s_def_hash_version;     /* Default hash version to use */
410         __u8    s_reserved_char_pad;
411         __u16   s_reserved_word_pad;
412         __le32  s_default_mount_opts;
413         __le32  s_first_meta_bg;        /* First metablock block group */
414         __u32   s_reserved[190];        /* Padding to the end of the block */
415 };
416
417 /*
418  * Codes for operating systems
419  */
420 #define EXT2_OS_LINUX           0
421 #define EXT2_OS_HURD            1
422 #define EXT2_OS_MASIX           2
423 #define EXT2_OS_FREEBSD         3
424 #define EXT2_OS_LITES           4
425
426 /*
427  * Revision levels
428  */
429 #define EXT2_GOOD_OLD_REV       0       /* The good old (original) format */
430 #define EXT2_DYNAMIC_REV        1       /* V2 format w/ dynamic inode sizes */
431
432 #define EXT2_CURRENT_REV        EXT2_GOOD_OLD_REV
433 #define EXT2_MAX_SUPP_REV       EXT2_DYNAMIC_REV
434
435 #define EXT2_GOOD_OLD_INODE_SIZE 128
436
437 /*
438  * Feature set definitions
439  */
440
441 #define EXT2_HAS_COMPAT_FEATURE(sb,mask)                        \
442         ( EXT2_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask) )
443 #define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask)                     \
444         ( EXT2_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask) )
445 #define EXT2_HAS_INCOMPAT_FEATURE(sb,mask)                      \
446         ( EXT2_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask) )
447 #define EXT2_SET_COMPAT_FEATURE(sb,mask)                        \
448         EXT2_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
449 #define EXT2_SET_RO_COMPAT_FEATURE(sb,mask)                     \
450         EXT2_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
451 #define EXT2_SET_INCOMPAT_FEATURE(sb,mask)                      \
452         EXT2_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
453 #define EXT2_CLEAR_COMPAT_FEATURE(sb,mask)                      \
454         EXT2_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
455 #define EXT2_CLEAR_RO_COMPAT_FEATURE(sb,mask)                   \
456         EXT2_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
457 #define EXT2_CLEAR_INCOMPAT_FEATURE(sb,mask)                    \
458         EXT2_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
459
460 #define EXT2_FEATURE_COMPAT_DIR_PREALLOC        0x0001
461 #define EXT2_FEATURE_COMPAT_IMAGIC_INODES       0x0002
462 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL         0x0004
463 #define EXT2_FEATURE_COMPAT_EXT_ATTR            0x0008
464 #define EXT2_FEATURE_COMPAT_RESIZE_INO          0x0010
465 #define EXT2_FEATURE_COMPAT_DIR_INDEX           0x0020
466 #define EXT2_FEATURE_COMPAT_ANY                 0xffffffff
467
468 #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER     0x0001
469 #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE       0x0002
470 #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR        0x0004
471 #define EXT2_FEATURE_RO_COMPAT_ANY              0xffffffff
472
473 #define EXT2_FEATURE_INCOMPAT_COMPRESSION       0x0001
474 #define EXT2_FEATURE_INCOMPAT_FILETYPE          0x0002
475 #define EXT3_FEATURE_INCOMPAT_RECOVER           0x0004
476 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV       0x0008
477 #define EXT2_FEATURE_INCOMPAT_META_BG           0x0010
478 #define EXT2_FEATURE_INCOMPAT_ANY               0xffffffff
479
480 #define EXT2_FEATURE_COMPAT_SUPP        EXT2_FEATURE_COMPAT_EXT_ATTR
481 #define EXT2_FEATURE_INCOMPAT_SUPP      (EXT2_FEATURE_INCOMPAT_FILETYPE| \
482                                          EXT2_FEATURE_INCOMPAT_META_BG)
483 #define EXT2_FEATURE_RO_COMPAT_SUPP     (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
484                                          EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
485                                          EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
486 #define EXT2_FEATURE_RO_COMPAT_UNSUPPORTED      ~EXT2_FEATURE_RO_COMPAT_SUPP
487 #define EXT2_FEATURE_INCOMPAT_UNSUPPORTED       ~EXT2_FEATURE_INCOMPAT_SUPP
488
489 /*
490  * Default values for user and/or group using reserved blocks
491  */
492 #define EXT2_DEF_RESUID         0
493 #define EXT2_DEF_RESGID         0
494
495 /*
496  * Default mount options
497  */
498 #define EXT2_DEFM_DEBUG         0x0001
499 #define EXT2_DEFM_BSDGROUPS     0x0002
500 #define EXT2_DEFM_XATTR_USER    0x0004
501 #define EXT2_DEFM_ACL           0x0008
502 #define EXT2_DEFM_UID16         0x0010
503     /* Not used by ext2, but reserved for use by ext3 */
504 #define EXT3_DEFM_JMODE         0x0060 
505 #define EXT3_DEFM_JMODE_DATA    0x0020
506 #define EXT3_DEFM_JMODE_ORDERED 0x0040
507 #define EXT3_DEFM_JMODE_WBACK   0x0060
508
509 /*
510  * Structure of a directory entry
511  */
512 #define EXT2_NAME_LEN 255
513
514 struct ext2_dir_entry {
515         __le32  inode;                  /* Inode number */
516         __le16  rec_len;                /* Directory entry length */
517         __le16  name_len;               /* Name length */
518         char    name[EXT2_NAME_LEN];    /* File name */
519 };
520
521 /*
522  * The new version of the directory entry.  Since EXT2 structures are
523  * stored in intel byte order, and the name_len field could never be
524  * bigger than 255 chars, it's safe to reclaim the extra byte for the
525  * file_type field.
526  */
527 struct ext2_dir_entry_2 {
528         __le32  inode;                  /* Inode number */
529         __le16  rec_len;                /* Directory entry length */
530         __u8    name_len;               /* Name length */
531         __u8    file_type;
532         char    name[EXT2_NAME_LEN];    /* File name */
533 };
534
535 /*
536  * Ext2 directory file types.  Only the low 3 bits are used.  The
537  * other bits are reserved for now.
538  */
539 enum {
540         EXT2_FT_UNKNOWN,
541         EXT2_FT_REG_FILE,
542         EXT2_FT_DIR,
543         EXT2_FT_CHRDEV,
544         EXT2_FT_BLKDEV,
545         EXT2_FT_FIFO,
546         EXT2_FT_SOCK,
547         EXT2_FT_SYMLINK,
548         EXT2_FT_MAX
549 };
550
551 /*
552  * EXT2_DIR_PAD defines the directory entries boundaries
553  *
554  * NOTE: It must be a multiple of 4
555  */
556 #define EXT2_DIR_PAD                    4
557 #define EXT2_DIR_ROUND                  (EXT2_DIR_PAD - 1)
558 #define EXT2_DIR_REC_LEN(name_len)      (((name_len) + 8 + EXT2_DIR_ROUND) & \
559                                          ~EXT2_DIR_ROUND)
560
561 #endif  /* _LINUX_EXT2_FS_H */