[PATCH] disk quotas fail when /etc/mtab is symlinked to /proc/mounts
[linux-2.6.git] / 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/ext2_fs_sb.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 /*
68  * The second extended file system magic number
69  */
70 #define EXT2_SUPER_MAGIC        0xEF53
71
72 #ifdef __KERNEL__
73 static inline struct ext2_sb_info *EXT2_SB(struct super_block *sb)
74 {
75         return sb->s_fs_info;
76 }
77 #else
78 /* Assume that user mode programs are passing in an ext2fs superblock, not
79  * a kernel struct super_block.  This will allow us to call the feature-test
80  * macros from user land. */
81 #define EXT2_SB(sb)     (sb)
82 #endif
83
84 /*
85  * Maximal count of links to a file
86  */
87 #define EXT2_LINK_MAX           32000
88
89 /*
90  * Macro-instructions used to manage several block sizes
91  */
92 #define EXT2_MIN_BLOCK_SIZE             1024
93 #define EXT2_MAX_BLOCK_SIZE             4096
94 #define EXT2_MIN_BLOCK_LOG_SIZE           10
95 #ifdef __KERNEL__
96 # define EXT2_BLOCK_SIZE(s)             ((s)->s_blocksize)
97 #else
98 # define EXT2_BLOCK_SIZE(s)             (EXT2_MIN_BLOCK_SIZE << (s)->s_log_block_size)
99 #endif
100 #define EXT2_ADDR_PER_BLOCK(s)          (EXT2_BLOCK_SIZE(s) / sizeof (__u32))
101 #ifdef __KERNEL__
102 # define EXT2_BLOCK_SIZE_BITS(s)        ((s)->s_blocksize_bits)
103 #else
104 # define EXT2_BLOCK_SIZE_BITS(s)        ((s)->s_log_block_size + 10)
105 #endif
106 #ifdef __KERNEL__
107 #define EXT2_ADDR_PER_BLOCK_BITS(s)     (EXT2_SB(s)->s_addr_per_block_bits)
108 #define EXT2_INODE_SIZE(s)              (EXT2_SB(s)->s_inode_size)
109 #define EXT2_FIRST_INO(s)               (EXT2_SB(s)->s_first_ino)
110 #else
111 #define EXT2_INODE_SIZE(s)      (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
112                                  EXT2_GOOD_OLD_INODE_SIZE : \
113                                  (s)->s_inode_size)
114 #define EXT2_FIRST_INO(s)       (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
115                                  EXT2_GOOD_OLD_FIRST_INO : \
116                                  (s)->s_first_ino)
117 #endif
118
119 /*
120  * Macro-instructions used to manage fragments
121  */
122 #define EXT2_MIN_FRAG_SIZE              1024
123 #define EXT2_MAX_FRAG_SIZE              4096
124 #define EXT2_MIN_FRAG_LOG_SIZE            10
125 #ifdef __KERNEL__
126 # define EXT2_FRAG_SIZE(s)              (EXT2_SB(s)->s_frag_size)
127 # define EXT2_FRAGS_PER_BLOCK(s)        (EXT2_SB(s)->s_frags_per_block)
128 #else
129 # define EXT2_FRAG_SIZE(s)              (EXT2_MIN_FRAG_SIZE << (s)->s_log_frag_size)
130 # define EXT2_FRAGS_PER_BLOCK(s)        (EXT2_BLOCK_SIZE(s) / EXT2_FRAG_SIZE(s))
131 #endif
132
133 /*
134  * Structure of a blocks group descriptor
135  */
136 struct ext2_group_desc
137 {
138         __le32  bg_block_bitmap;                /* Blocks bitmap block */
139         __le32  bg_inode_bitmap;                /* Inodes bitmap block */
140         __le32  bg_inode_table;         /* Inodes table block */
141         __le16  bg_free_blocks_count;   /* Free blocks count */
142         __le16  bg_free_inodes_count;   /* Free inodes count */
143         __le16  bg_used_dirs_count;     /* Directories count */
144         __le16  bg_pad;
145         __le32  bg_reserved[3];
146 };
147
148 /*
149  * Macro-instructions used to manage group descriptors
150  */
151 #ifdef __KERNEL__
152 # define EXT2_BLOCKS_PER_GROUP(s)       (EXT2_SB(s)->s_blocks_per_group)
153 # define EXT2_DESC_PER_BLOCK(s)         (EXT2_SB(s)->s_desc_per_block)
154 # define EXT2_INODES_PER_GROUP(s)       (EXT2_SB(s)->s_inodes_per_group)
155 # define EXT2_DESC_PER_BLOCK_BITS(s)    (EXT2_SB(s)->s_desc_per_block_bits)
156 #else
157 # define EXT2_BLOCKS_PER_GROUP(s)       ((s)->s_blocks_per_group)
158 # define EXT2_DESC_PER_BLOCK(s)         (EXT2_BLOCK_SIZE(s) / sizeof (struct ext2_group_desc))
159 # define EXT2_INODES_PER_GROUP(s)       ((s)->s_inodes_per_group)
160 #endif
161
162 /*
163  * Constants relative to the data blocks
164  */
165 #define EXT2_NDIR_BLOCKS                12
166 #define EXT2_IND_BLOCK                  EXT2_NDIR_BLOCKS
167 #define EXT2_DIND_BLOCK                 (EXT2_IND_BLOCK + 1)
168 #define EXT2_TIND_BLOCK                 (EXT2_DIND_BLOCK + 1)
169 #define EXT2_N_BLOCKS                   (EXT2_TIND_BLOCK + 1)
170
171 /*
172  * Inode flags
173  */
174 #define EXT2_SECRM_FL                   0x00000001 /* Secure deletion */
175 #define EXT2_UNRM_FL                    0x00000002 /* Undelete */
176 #define EXT2_COMPR_FL                   0x00000004 /* Compress file */
177 #define EXT2_SYNC_FL                    0x00000008 /* Synchronous updates */
178 #define EXT2_IMMUTABLE_FL               0x00000010 /* Immutable file */
179 #define EXT2_APPEND_FL                  0x00000020 /* writes to file may only append */
180 #define EXT2_NODUMP_FL                  0x00000040 /* do not dump file */
181 #define EXT2_NOATIME_FL                 0x00000080 /* do not update atime */
182 /* Reserved for compression usage... */
183 #define EXT2_DIRTY_FL                   0x00000100
184 #define EXT2_COMPRBLK_FL                0x00000200 /* One or more compressed clusters */
185 #define EXT2_NOCOMP_FL                  0x00000400 /* Don't compress */
186 #define EXT2_ECOMPR_FL                  0x00000800 /* Compression error */
187 /* End compression flags --- maybe not all used */      
188 #define EXT2_BTREE_FL                   0x00001000 /* btree format dir */
189 #define EXT2_INDEX_FL                   0x00001000 /* hash-indexed directory */
190 #define EXT2_IMAGIC_FL                  0x00002000 /* AFS directory */
191 #define EXT2_JOURNAL_DATA_FL            0x00004000 /* Reserved for ext3 */
192 #define EXT2_NOTAIL_FL                  0x00008000 /* file tail should not be merged */
193 #define EXT2_DIRSYNC_FL                 0x00010000 /* dirsync behaviour (directories only) */
194 #define EXT2_TOPDIR_FL                  0x00020000 /* Top of directory hierarchies*/
195 #define EXT2_RESERVED_FL                0x80000000 /* reserved for ext2 lib */
196
197 #define EXT2_FL_USER_VISIBLE            0x0003DFFF /* User visible flags */
198 #define EXT2_FL_USER_MODIFIABLE         0x000380FF /* User modifiable flags */
199
200 /*
201  * ioctl commands
202  */
203 #define EXT2_IOC_GETFLAGS               _IOR('f', 1, long)
204 #define EXT2_IOC_SETFLAGS               _IOW('f', 2, long)
205 #define EXT2_IOC_GETVERSION             _IOR('v', 1, long)
206 #define EXT2_IOC_SETVERSION             _IOW('v', 2, long)
207
208 /*
209  * Structure of an inode on the disk
210  */
211 struct ext2_inode {
212         __le16  i_mode;         /* File mode */
213         __le16  i_uid;          /* Low 16 bits of Owner Uid */
214         __le32  i_size;         /* Size in bytes */
215         __le32  i_atime;        /* Access time */
216         __le32  i_ctime;        /* Creation time */
217         __le32  i_mtime;        /* Modification time */
218         __le32  i_dtime;        /* Deletion Time */
219         __le16  i_gid;          /* Low 16 bits of Group Id */
220         __le16  i_links_count;  /* Links count */
221         __le32  i_blocks;       /* Blocks count */
222         __le32  i_flags;        /* File flags */
223         union {
224                 struct {
225                         __le32  l_i_reserved1;
226                 } linux1;
227                 struct {
228                         __le32  h_i_translator;
229                 } hurd1;
230                 struct {
231                         __le32  m_i_reserved1;
232                 } masix1;
233         } osd1;                         /* OS dependent 1 */
234         __le32  i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
235         __le32  i_generation;   /* File version (for NFS) */
236         __le32  i_file_acl;     /* File ACL */
237         __le32  i_dir_acl;      /* Directory ACL */
238         __le32  i_faddr;        /* Fragment address */
239         union {
240                 struct {
241                         __u8    l_i_frag;       /* Fragment number */
242                         __u8    l_i_fsize;      /* Fragment size */
243                         __u16   i_pad1;
244                         __le16  l_i_uid_high;   /* these 2 fields    */
245                         __le16  l_i_gid_high;   /* were reserved2[0] */
246                         __u32   l_i_reserved2;
247                 } linux2;
248                 struct {
249                         __u8    h_i_frag;       /* Fragment number */
250                         __u8    h_i_fsize;      /* Fragment size */
251                         __le16  h_i_mode_high;
252                         __le16  h_i_uid_high;
253                         __le16  h_i_gid_high;
254                         __le32  h_i_author;
255                 } hurd2;
256                 struct {
257                         __u8    m_i_frag;       /* Fragment number */
258                         __u8    m_i_fsize;      /* Fragment size */
259                         __u16   m_pad1;
260                         __u32   m_i_reserved2[2];
261                 } masix2;
262         } osd2;                         /* OS dependent 2 */
263 };
264
265 #define i_size_high     i_dir_acl
266
267 #if defined(__KERNEL__) || defined(__linux__)
268 #define i_reserved1     osd1.linux1.l_i_reserved1
269 #define i_frag          osd2.linux2.l_i_frag
270 #define i_fsize         osd2.linux2.l_i_fsize
271 #define i_uid_low       i_uid
272 #define i_gid_low       i_gid
273 #define i_uid_high      osd2.linux2.l_i_uid_high
274 #define i_gid_high      osd2.linux2.l_i_gid_high
275 #define i_reserved2     osd2.linux2.l_i_reserved2
276 #endif
277
278 #ifdef  __hurd__
279 #define i_translator    osd1.hurd1.h_i_translator
280 #define i_frag          osd2.hurd2.h_i_frag;
281 #define i_fsize         osd2.hurd2.h_i_fsize;
282 #define i_uid_high      osd2.hurd2.h_i_uid_high
283 #define i_gid_high      osd2.hurd2.h_i_gid_high
284 #define i_author        osd2.hurd2.h_i_author
285 #endif
286
287 #ifdef  __masix__
288 #define i_reserved1     osd1.masix1.m_i_reserved1
289 #define i_frag          osd2.masix2.m_i_frag
290 #define i_fsize         osd2.masix2.m_i_fsize
291 #define i_reserved2     osd2.masix2.m_i_reserved2
292 #endif
293
294 /*
295  * File system states
296  */
297 #define EXT2_VALID_FS                   0x0001  /* Unmounted cleanly */
298 #define EXT2_ERROR_FS                   0x0002  /* Errors detected */
299
300 /*
301  * Mount flags
302  */
303 #define EXT2_MOUNT_CHECK                0x000001  /* Do mount-time checks */
304 #define EXT2_MOUNT_OLDALLOC             0x000002  /* Don't use the new Orlov allocator */
305 #define EXT2_MOUNT_GRPID                0x000004  /* Create files with directory's group */
306 #define EXT2_MOUNT_DEBUG                0x000008  /* Some debugging messages */
307 #define EXT2_MOUNT_ERRORS_CONT          0x000010  /* Continue on errors */
308 #define EXT2_MOUNT_ERRORS_RO            0x000020  /* Remount fs ro on errors */
309 #define EXT2_MOUNT_ERRORS_PANIC         0x000040  /* Panic on errors */
310 #define EXT2_MOUNT_MINIX_DF             0x000080  /* Mimics the Minix statfs */
311 #define EXT2_MOUNT_NOBH                 0x000100  /* No buffer_heads */
312 #define EXT2_MOUNT_NO_UID32             0x000200  /* Disable 32-bit UIDs */
313 #define EXT2_MOUNT_XATTR_USER           0x004000  /* Extended user attributes */
314 #define EXT2_MOUNT_POSIX_ACL            0x008000  /* POSIX Access Control Lists */
315 #define EXT2_MOUNT_XIP                  0x010000  /* Execute in place */
316 #define EXT2_MOUNT_USRQUOTA             0x020000 /* user quota */
317 #define EXT2_MOUNT_GRPQUOTA             0x040000 /* group quota */
318
319
320 #define clear_opt(o, opt)               o &= ~EXT2_MOUNT_##opt
321 #define set_opt(o, opt)                 o |= EXT2_MOUNT_##opt
322 #define test_opt(sb, opt)               (EXT2_SB(sb)->s_mount_opt & \
323                                          EXT2_MOUNT_##opt)
324 /*
325  * Maximal mount counts between two filesystem checks
326  */
327 #define EXT2_DFL_MAX_MNT_COUNT          20      /* Allow 20 mounts */
328 #define EXT2_DFL_CHECKINTERVAL          0       /* Don't use interval check */
329
330 /*
331  * Behaviour when detecting errors
332  */
333 #define EXT2_ERRORS_CONTINUE            1       /* Continue execution */
334 #define EXT2_ERRORS_RO                  2       /* Remount fs read-only */
335 #define EXT2_ERRORS_PANIC               3       /* Panic */
336 #define EXT2_ERRORS_DEFAULT             EXT2_ERRORS_CONTINUE
337
338 /*
339  * Structure of the super block
340  */
341 struct ext2_super_block {
342         __le32  s_inodes_count;         /* Inodes count */
343         __le32  s_blocks_count;         /* Blocks count */
344         __le32  s_r_blocks_count;       /* Reserved blocks count */
345         __le32  s_free_blocks_count;    /* Free blocks count */
346         __le32  s_free_inodes_count;    /* Free inodes count */
347         __le32  s_first_data_block;     /* First Data Block */
348         __le32  s_log_block_size;       /* Block size */
349         __le32  s_log_frag_size;        /* Fragment size */
350         __le32  s_blocks_per_group;     /* # Blocks per group */
351         __le32  s_frags_per_group;      /* # Fragments per group */
352         __le32  s_inodes_per_group;     /* # Inodes per group */
353         __le32  s_mtime;                /* Mount time */
354         __le32  s_wtime;                /* Write time */
355         __le16  s_mnt_count;            /* Mount count */
356         __le16  s_max_mnt_count;        /* Maximal mount count */
357         __le16  s_magic;                /* Magic signature */
358         __le16  s_state;                /* File system state */
359         __le16  s_errors;               /* Behaviour when detecting errors */
360         __le16  s_minor_rev_level;      /* minor revision level */
361         __le32  s_lastcheck;            /* time of last check */
362         __le32  s_checkinterval;        /* max. time between checks */
363         __le32  s_creator_os;           /* OS */
364         __le32  s_rev_level;            /* Revision level */
365         __le16  s_def_resuid;           /* Default uid for reserved blocks */
366         __le16  s_def_resgid;           /* Default gid for reserved blocks */
367         /*
368          * These fields are for EXT2_DYNAMIC_REV superblocks only.
369          *
370          * Note: the difference between the compatible feature set and
371          * the incompatible feature set is that if there is a bit set
372          * in the incompatible feature set that the kernel doesn't
373          * know about, it should refuse to mount the filesystem.
374          * 
375          * e2fsck's requirements are more strict; if it doesn't know
376          * about a feature in either the compatible or incompatible
377          * feature set, it must abort and not try to meddle with
378          * things it doesn't understand...
379          */
380         __le32  s_first_ino;            /* First non-reserved inode */
381         __le16   s_inode_size;          /* size of inode structure */
382         __le16  s_block_group_nr;       /* block group # of this superblock */
383         __le32  s_feature_compat;       /* compatible feature set */
384         __le32  s_feature_incompat;     /* incompatible feature set */
385         __le32  s_feature_ro_compat;    /* readonly-compatible feature set */
386         __u8    s_uuid[16];             /* 128-bit uuid for volume */
387         char    s_volume_name[16];      /* volume name */
388         char    s_last_mounted[64];     /* directory where last mounted */
389         __le32  s_algorithm_usage_bitmap; /* For compression */
390         /*
391          * Performance hints.  Directory preallocation should only
392          * happen if the EXT2_COMPAT_PREALLOC flag is on.
393          */
394         __u8    s_prealloc_blocks;      /* Nr of blocks to try to preallocate*/
395         __u8    s_prealloc_dir_blocks;  /* Nr to preallocate for dirs */
396         __u16   s_padding1;
397         /*
398          * Journaling support valid if EXT3_FEATURE_COMPAT_HAS_JOURNAL set.
399          */
400         __u8    s_journal_uuid[16];     /* uuid of journal superblock */
401         __u32   s_journal_inum;         /* inode number of journal file */
402         __u32   s_journal_dev;          /* device number of journal file */
403         __u32   s_last_orphan;          /* start of list of inodes to delete */
404         __u32   s_hash_seed[4];         /* HTREE hash seed */
405         __u8    s_def_hash_version;     /* Default hash version to use */
406         __u8    s_reserved_char_pad;
407         __u16   s_reserved_word_pad;
408         __le32  s_default_mount_opts;
409         __le32  s_first_meta_bg;        /* First metablock block group */
410         __u32   s_reserved[190];        /* Padding to the end of the block */
411 };
412
413 /*
414  * Codes for operating systems
415  */
416 #define EXT2_OS_LINUX           0
417 #define EXT2_OS_HURD            1
418 #define EXT2_OS_MASIX           2
419 #define EXT2_OS_FREEBSD         3
420 #define EXT2_OS_LITES           4
421
422 /*
423  * Revision levels
424  */
425 #define EXT2_GOOD_OLD_REV       0       /* The good old (original) format */
426 #define EXT2_DYNAMIC_REV        1       /* V2 format w/ dynamic inode sizes */
427
428 #define EXT2_CURRENT_REV        EXT2_GOOD_OLD_REV
429 #define EXT2_MAX_SUPP_REV       EXT2_DYNAMIC_REV
430
431 #define EXT2_GOOD_OLD_INODE_SIZE 128
432
433 /*
434  * Feature set definitions
435  */
436
437 #define EXT2_HAS_COMPAT_FEATURE(sb,mask)                        \
438         ( EXT2_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask) )
439 #define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask)                     \
440         ( EXT2_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask) )
441 #define EXT2_HAS_INCOMPAT_FEATURE(sb,mask)                      \
442         ( EXT2_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask) )
443 #define EXT2_SET_COMPAT_FEATURE(sb,mask)                        \
444         EXT2_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
445 #define EXT2_SET_RO_COMPAT_FEATURE(sb,mask)                     \
446         EXT2_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
447 #define EXT2_SET_INCOMPAT_FEATURE(sb,mask)                      \
448         EXT2_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
449 #define EXT2_CLEAR_COMPAT_FEATURE(sb,mask)                      \
450         EXT2_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
451 #define EXT2_CLEAR_RO_COMPAT_FEATURE(sb,mask)                   \
452         EXT2_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
453 #define EXT2_CLEAR_INCOMPAT_FEATURE(sb,mask)                    \
454         EXT2_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
455
456 #define EXT2_FEATURE_COMPAT_DIR_PREALLOC        0x0001
457 #define EXT2_FEATURE_COMPAT_IMAGIC_INODES       0x0002
458 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL         0x0004
459 #define EXT2_FEATURE_COMPAT_EXT_ATTR            0x0008
460 #define EXT2_FEATURE_COMPAT_RESIZE_INO          0x0010
461 #define EXT2_FEATURE_COMPAT_DIR_INDEX           0x0020
462 #define EXT2_FEATURE_COMPAT_ANY                 0xffffffff
463
464 #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER     0x0001
465 #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE       0x0002
466 #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR        0x0004
467 #define EXT2_FEATURE_RO_COMPAT_ANY              0xffffffff
468
469 #define EXT2_FEATURE_INCOMPAT_COMPRESSION       0x0001
470 #define EXT2_FEATURE_INCOMPAT_FILETYPE          0x0002
471 #define EXT3_FEATURE_INCOMPAT_RECOVER           0x0004
472 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV       0x0008
473 #define EXT2_FEATURE_INCOMPAT_META_BG           0x0010
474 #define EXT2_FEATURE_INCOMPAT_ANY               0xffffffff
475
476 #define EXT2_FEATURE_COMPAT_SUPP        EXT2_FEATURE_COMPAT_EXT_ATTR
477 #define EXT2_FEATURE_INCOMPAT_SUPP      (EXT2_FEATURE_INCOMPAT_FILETYPE| \
478                                          EXT2_FEATURE_INCOMPAT_META_BG)
479 #define EXT2_FEATURE_RO_COMPAT_SUPP     (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
480                                          EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
481                                          EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
482 #define EXT2_FEATURE_RO_COMPAT_UNSUPPORTED      ~EXT2_FEATURE_RO_COMPAT_SUPP
483 #define EXT2_FEATURE_INCOMPAT_UNSUPPORTED       ~EXT2_FEATURE_INCOMPAT_SUPP
484
485 /*
486  * Default values for user and/or group using reserved blocks
487  */
488 #define EXT2_DEF_RESUID         0
489 #define EXT2_DEF_RESGID         0
490
491 /*
492  * Default mount options
493  */
494 #define EXT2_DEFM_DEBUG         0x0001
495 #define EXT2_DEFM_BSDGROUPS     0x0002
496 #define EXT2_DEFM_XATTR_USER    0x0004
497 #define EXT2_DEFM_ACL           0x0008
498 #define EXT2_DEFM_UID16         0x0010
499     /* Not used by ext2, but reserved for use by ext3 */
500 #define EXT3_DEFM_JMODE         0x0060 
501 #define EXT3_DEFM_JMODE_DATA    0x0020
502 #define EXT3_DEFM_JMODE_ORDERED 0x0040
503 #define EXT3_DEFM_JMODE_WBACK   0x0060
504
505 /*
506  * Structure of a directory entry
507  */
508 #define EXT2_NAME_LEN 255
509
510 struct ext2_dir_entry {
511         __le32  inode;                  /* Inode number */
512         __le16  rec_len;                /* Directory entry length */
513         __le16  name_len;               /* Name length */
514         char    name[EXT2_NAME_LEN];    /* File name */
515 };
516
517 /*
518  * The new version of the directory entry.  Since EXT2 structures are
519  * stored in intel byte order, and the name_len field could never be
520  * bigger than 255 chars, it's safe to reclaim the extra byte for the
521  * file_type field.
522  */
523 struct ext2_dir_entry_2 {
524         __le32  inode;                  /* Inode number */
525         __le16  rec_len;                /* Directory entry length */
526         __u8    name_len;               /* Name length */
527         __u8    file_type;
528         char    name[EXT2_NAME_LEN];    /* File name */
529 };
530
531 /*
532  * Ext2 directory file types.  Only the low 3 bits are used.  The
533  * other bits are reserved for now.
534  */
535 enum {
536         EXT2_FT_UNKNOWN,
537         EXT2_FT_REG_FILE,
538         EXT2_FT_DIR,
539         EXT2_FT_CHRDEV,
540         EXT2_FT_BLKDEV,
541         EXT2_FT_FIFO,
542         EXT2_FT_SOCK,
543         EXT2_FT_SYMLINK,
544         EXT2_FT_MAX
545 };
546
547 /*
548  * EXT2_DIR_PAD defines the directory entries boundaries
549  *
550  * NOTE: It must be a multiple of 4
551  */
552 #define EXT2_DIR_PAD                    4
553 #define EXT2_DIR_ROUND                  (EXT2_DIR_PAD - 1)
554 #define EXT2_DIR_REC_LEN(name_len)      (((name_len) + 8 + EXT2_DIR_ROUND) & \
555                                          ~EXT2_DIR_ROUND)
556
557 #endif  /* _LINUX_EXT2_FS_H */