fs/jffs2/nodelist.h

   1 /*
   2  * JFFS2 -- Journalling Flash File System, Version 2.
   3  *
   4  * Copyright (C) 2001-2003 Red Hat, Inc.
   5  *
   6  * Created by David Woodhouse <dwmw2@infradead.org>
   7  *
   8  * For licensing information, see the file 'LICENCE' in this directory.
   9  *
  10  * $Id: nodelist.h,v 1.140 2005/09/07 08:34:54 havasi Exp $
  11  *
  12  */
  13
  14 #ifndef __JFFS2_NODELIST_H__
  15 #define __JFFS2_NODELIST_H__
  16
  17 #include <linux/config.h>
  18 #include <linux/fs.h>
  19 #include <linux/types.h>
  20 #include <linux/jffs2.h>
  21 #include "jffs2_fs_sb.h"
  22 #include "jffs2_fs_i.h"
  23 #include "xattr.h"
  24 #include "acl.h"
  25 #include "summary.h"
  26
  27 #ifdef __ECOS
  28 #include "os-ecos.h"
  29 #else
  30 #include <linux/mtd/compatmac.h> /* For compatibility with older kernels */
  31 #include "os-linux.h"
  32 #endif
  33
  34 #define JFFS2_NATIVE_ENDIAN
  35
  36 /* Note we handle mode bits conversion from JFFS2 (i.e. Linux) to/from
  37    whatever OS we're actually running on here too. */
  38
  39 #if defined(JFFS2_NATIVE_ENDIAN)
  40 #define cpu_to_je16(x) ((jint16_t){x})
  41 #define cpu_to_je32(x) ((jint32_t){x})
  42 #define cpu_to_jemode(x) ((jmode_t){os_to_jffs2_mode(x)})
  43
  44 #define je16_to_cpu(x) ((x).v16)
  45 #define je32_to_cpu(x) ((x).v32)
  46 #define jemode_to_cpu(x) (jffs2_to_os_mode((x).m))
  47 #elif defined(JFFS2_BIG_ENDIAN)
  48 #define cpu_to_je16(x) ((jint16_t){cpu_to_be16(x)})
  49 #define cpu_to_je32(x) ((jint32_t){cpu_to_be32(x)})
  50 #define cpu_to_jemode(x) ((jmode_t){cpu_to_be32(os_to_jffs2_mode(x))})
  51
  52 #define je16_to_cpu(x) (be16_to_cpu(x.v16))
  53 #define je32_to_cpu(x) (be32_to_cpu(x.v32))
  54 #define jemode_to_cpu(x) (be32_to_cpu(jffs2_to_os_mode((x).m)))
  55 #elif defined(JFFS2_LITTLE_ENDIAN)
  56 #define cpu_to_je16(x) ((jint16_t){cpu_to_le16(x)})
  57 #define cpu_to_je32(x) ((jint32_t){cpu_to_le32(x)})
  58 #define cpu_to_jemode(x) ((jmode_t){cpu_to_le32(os_to_jffs2_mode(x))})
  59
  60 #define je16_to_cpu(x) (le16_to_cpu(x.v16))
  61 #define je32_to_cpu(x) (le32_to_cpu(x.v32))
  62 #define jemode_to_cpu(x) (le32_to_cpu(jffs2_to_os_mode((x).m)))
  63 #else
  64 #error wibble
  65 #endif
  66
  67 /* The minimal node header size */
  68 #define JFFS2_MIN_NODE_HEADER sizeof(struct jffs2_raw_dirent)
  69
  70 /*
  71   This is all we need to keep in-core for each raw node during normal
  72   operation. As and when we do read_inode on a particular inode, we can
  73   scan the nodes which are listed for it and build up a proper map of
  74   which nodes are currently valid. JFFSv1 always used to keep that whole
  75   map in core for each inode.
  76 */
  77 struct jffs2_raw_node_ref
  78 {
  79         struct jffs2_raw_node_ref *next_in_ino; /* Points to the next raw_node_ref
  80                 for this object. If this _is_ the last, it points to the inode_cache,
  81                 xattr_ref or xattr_datum instead. The common part of those structures
  82                 has NULL in the first word. See jffs2_raw_ref_to_ic() below */
  83         uint32_t flash_offset;
  84 #define TEST_TOTLEN
  85 #ifdef TEST_TOTLEN
  86         uint32_t __totlen; /* This may die; use ref_totlen(c, jeb, ) below */
  87 #endif
  88 };
  89
  90 #define REF_LINK_NODE ((int32_t)-1)
  91 #define REF_EMPTY_NODE ((int32_t)-2)
  92
  93 /* Use blocks of about 256 bytes */
  94 #define REFS_PER_BLOCK ((255/sizeof(struct jffs2_raw_node_ref))-1)
  95
  96 static inline struct jffs2_raw_node_ref *ref_next(struct jffs2_raw_node_ref *ref)
  97 {
  98         ref++;
  99
 100         /* Link to another block of refs */
 101         if (ref->flash_offset == REF_LINK_NODE) {
 102                 ref = ref->next_in_ino;
 103                 if (!ref)
 104                         return ref;
 105         }
 106
 107         /* End of chain */
 108         if (ref->flash_offset == REF_EMPTY_NODE)
 109                 return NULL;
 110
 111         return ref;
 112 }
 113
 114 static inline struct jffs2_inode_cache *jffs2_raw_ref_to_ic(struct jffs2_raw_node_ref *raw)
 115 {
 116         while(raw->next_in_ino)
 117                 raw = raw->next_in_ino;
 118
 119         /* NB. This can be a jffs2_xattr_datum or jffs2_xattr_ref and
 120            not actually a jffs2_inode_cache. Check ->class */
 121         return ((struct jffs2_inode_cache *)raw);
 122 }
 123
 124         /* flash_offset & 3 always has to be zero, because nodes are
 125            always aligned at 4 bytes. So we have a couple of extra bits
 126            to play with, which indicate the node's status; see below: */
 127 #define REF_UNCHECKED   0       /* We haven't yet checked the CRC or built its inode */
 128 #define REF_OBSOLETE    1       /* Obsolete, can be completely ignored */
 129 #define REF_PRISTINE    2       /* Completely clean. GC without looking */
 130 #define REF_NORMAL      3       /* Possibly overlapped. Read the page and write again on GC */
 131 #define ref_flags(ref)          ((ref)->flash_offset & 3)
 132 #define ref_offset(ref)         ((ref)->flash_offset & ~3)
 133 #define ref_obsolete(ref)       (((ref)->flash_offset & 3) == REF_OBSOLETE)
 134 #define mark_ref_normal(ref)    do { (ref)->flash_offset = ref_offset(ref) | REF_NORMAL; } while(0)
 135
 136 /* NB: REF_PRISTINE for an inode-less node (ref->next_in_ino == NULL) indicates
 137    it is an unknown node of type JFFS2_NODETYPE_RWCOMPAT_COPY, so it'll get
 138    copied. If you need to do anything different to GC inode-less nodes, then
 139    you need to modify gc.c accordingly. */
 140
 141 /* For each inode in the filesystem, we need to keep a record of
 142    nlink, because it would be a PITA to scan the whole directory tree
 143    at read_inode() time to calculate it, and to keep sufficient information
 144    in the raw_node_ref (basically both parent and child inode number for
 145    dirent nodes) would take more space than this does. We also keep
 146    a pointer to the first physical node which is part of this inode, too.
 147 */
 148 struct jffs2_inode_cache {
 149         /* First part of structure is shared with other objects which
 150            can terminate the raw node refs' next_in_ino list -- which
 151            currently struct jffs2_xattr_datum and struct jffs2_xattr_ref. */
 152
 153         struct jffs2_full_dirent *scan_dents; /* Used during scan to hold
 154                 temporary lists of dirents, and later must be set to
 155                 NULL to mark the end of the raw_node_ref->next_in_ino
 156                 chain. */
 157         struct jffs2_raw_node_ref *nodes;
 158         uint8_t class;  /* It's used for identification */
 159
 160         /* end of shared structure */
 161
 162         uint8_t flags;
 163         uint16_t state;
 164         uint32_t ino;
 165         struct jffs2_inode_cache *next;
 166 #ifdef CONFIG_JFFS2_FS_XATTR
 167         struct jffs2_xattr_ref *xref;
 168 #endif
 169         int nlink;
 170 };
 171
 172 /* Inode states for 'state' above. We need the 'GC' state to prevent
 173    someone from doing a read_inode() while we're moving a 'REF_PRISTINE'
 174    node without going through all the iget() nonsense */
 175 #define INO_STATE_UNCHECKED     0       /* CRC checks not yet done */
 176 #define INO_STATE_CHECKING      1       /* CRC checks in progress */
 177 #define INO_STATE_PRESENT       2       /* In core */
 178 #define INO_STATE_CHECKEDABSENT 3       /* Checked, cleared again */
 179 #define INO_STATE_GC            4       /* GCing a 'pristine' node */
 180 #define INO_STATE_READING       5       /* In read_inode() */
 181 #define INO_STATE_CLEARING      6       /* In clear_inode() */
 182
 183 #define INO_FLAGS_XATTR_CHECKED 0x01    /* has no duplicate xattr_ref */
 184
 185 #define RAWNODE_CLASS_INODE_CACHE       0
 186 #define RAWNODE_CLASS_XATTR_DATUM       1
 187 #define RAWNODE_CLASS_XATTR_REF         2
 188
 189 #define INOCACHE_HASHSIZE 128
 190
 191 #define write_ofs(c) ((c)->nextblock->offset + (c)->sector_size - (c)->nextblock->free_size)
 192
 193 /*
 194   Larger representation of a raw node, kept in-core only when the
 195   struct inode for this particular ino is instantiated.
 196 */
 197
 198 struct jffs2_full_dnode
 199 {
 200         struct jffs2_raw_node_ref *raw;
 201         uint32_t ofs; /* The offset to which the data of this node belongs */
 202         uint32_t size;
 203         uint32_t frags; /* Number of fragments which currently refer
 204                         to this node. When this reaches zero,
 205                         the node is obsolete.  */
 206 };
 207
 208 /*
 209    Even larger representation of a raw node, kept in-core only while
 210    we're actually building up the original map of which nodes go where,
 211    in read_inode()
 212 */
 213 struct jffs2_tmp_dnode_info
 214 {
 215         struct rb_node rb;
 216         struct jffs2_full_dnode *fn;
 217         uint32_t version;
 218         uint32_t data_crc;
 219         uint32_t partial_crc;
 220         uint32_t csize;
 221 };
 222
 223 struct jffs2_full_dirent
 224 {
 225         struct jffs2_raw_node_ref *raw;
 226         struct jffs2_full_dirent *next;
 227         uint32_t version;
 228         uint32_t ino; /* == zero for unlink */
 229         unsigned int nhash;
 230         unsigned char type;
 231         unsigned char name[0];
 232 };
 233
 234 /*
 235   Fragments - used to build a map of which raw node to obtain
 236   data from for each part of the ino
 237 */
 238 struct jffs2_node_frag
 239 {
 240         struct rb_node rb;
 241         struct jffs2_full_dnode *node; /* NULL for holes */
 242         uint32_t size;
 243         uint32_t ofs; /* The offset to which this fragment belongs */
 244 };
 245
 246 struct jffs2_eraseblock
 247 {
 248         struct list_head list;
 249         int bad_count;
 250         uint32_t offset;                /* of this block in the MTD */
 251
 252         uint32_t unchecked_size;
 253         uint32_t used_size;
 254         uint32_t dirty_size;
 255         uint32_t wasted_size;
 256         uint32_t free_size;     /* Note that sector_size - free_size
 257                                    is the address of the first free space */
 258         uint32_t allocated_refs;
 259         struct jffs2_raw_node_ref *first_node;
 260         struct jffs2_raw_node_ref *last_node;
 261
 262         struct jffs2_raw_node_ref *gc_node;     /* Next node to be garbage collected */
 263 };
 264
 265 static inline int jffs2_blocks_use_vmalloc(struct jffs2_sb_info *c)
 266 {
 267         return ((c->flash_size / c->sector_size) * sizeof (struct jffs2_eraseblock)) > (128 * 1024);
 268 }
 269
 270 #define ref_totlen(a, b, c) __jffs2_ref_totlen((a), (b), (c))
 271
 272 #define ALLOC_NORMAL    0       /* Normal allocation */
 273 #define ALLOC_DELETION  1       /* Deletion node. Best to allow it */
 274 #define ALLOC_GC        2       /* Space requested for GC. Give it or die */
 275 #define ALLOC_NORETRY   3       /* For jffs2_write_dnode: On failure, return -EAGAIN instead of retrying */
 276
 277 /* How much dirty space before it goes on the very_dirty_list */
 278 #define VERYDIRTY(c, size) ((size) >= ((c)->sector_size / 2))
 279
 280 /* check if dirty space is more than 255 Byte */
 281 #define ISDIRTY(size) ((size) >  sizeof (struct jffs2_raw_inode) + JFFS2_MIN_DATA_LEN)
 282
 283 #define PAD(x) (((x)+3)&~3)
 284
 285 static inline int jffs2_encode_dev(union jffs2_device_node *jdev, dev_t rdev)
 286 {
 287         if (old_valid_dev(rdev)) {
 288                 jdev->old = cpu_to_je16(old_encode_dev(rdev));
 289                 return sizeof(jdev->old);
 290         } else {
 291                 jdev->new = cpu_to_je32(new_encode_dev(rdev));
 292                 return sizeof(jdev->new);
 293         }
 294 }
 295
 296 static inline struct jffs2_node_frag *frag_first(struct rb_root *root)
 297 {
 298         struct rb_node *node = root->rb_node;
 299
 300         if (!node)
 301                 return NULL;
 302         while(node->rb_left)
 303                 node = node->rb_left;
 304         return rb_entry(node, struct jffs2_node_frag, rb);
 305 }
 306
 307 static inline struct jffs2_node_frag *frag_last(struct rb_root *root)
 308 {
 309         struct rb_node *node = root->rb_node;
 310
 311         if (!node)
 312                 return NULL;
 313         while(node->rb_right)
 314                 node = node->rb_right;
 315         return rb_entry(node, struct jffs2_node_frag, rb);
 316 }
 317
 318 #define frag_next(frag) rb_entry(rb_next(&(frag)->rb), struct jffs2_node_frag, rb)
 319 #define frag_prev(frag) rb_entry(rb_prev(&(frag)->rb), struct jffs2_node_frag, rb)
 320 #define frag_parent(frag) rb_entry(rb_parent(&(frag)->rb), struct jffs2_node_frag, rb)
 321 #define frag_left(frag) rb_entry((frag)->rb.rb_left, struct jffs2_node_frag, rb)
 322 #define frag_right(frag) rb_entry((frag)->rb.rb_right, struct jffs2_node_frag, rb)
 323 #define frag_erase(frag, list) rb_erase(&frag->rb, list);
 324
 325 /* nodelist.c */
 326 void jffs2_add_fd_to_list(struct jffs2_sb_info *c, struct jffs2_full_dirent *new, struct jffs2_full_dirent **list);
 327 void jffs2_set_inocache_state(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic, int state);
 328 struct jffs2_inode_cache *jffs2_get_ino_cache(struct jffs2_sb_info *c, uint32_t ino);
 329 void jffs2_add_ino_cache (struct jffs2_sb_info *c, struct jffs2_inode_cache *new);
 330 void jffs2_del_ino_cache(struct jffs2_sb_info *c, struct jffs2_inode_cache *old);
 331 void jffs2_free_ino_caches(struct jffs2_sb_info *c);
 332 void jffs2_free_raw_node_refs(struct jffs2_sb_info *c);
 333 struct jffs2_node_frag *jffs2_lookup_node_frag(struct rb_root *fragtree, uint32_t offset);
 334 void jffs2_kill_fragtree(struct rb_root *root, struct jffs2_sb_info *c_delete);
 335 struct rb_node *rb_next(struct rb_node *);
 336 struct rb_node *rb_prev(struct rb_node *);
 337 void rb_replace_node(struct rb_node *victim, struct rb_node *new, struct rb_root *root);
 338 void jffs2_obsolete_node_frag(struct jffs2_sb_info *c, struct jffs2_node_frag *this);
 339 int jffs2_add_full_dnode_to_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f, struct jffs2_full_dnode *fn);
 340 void jffs2_truncate_fragtree (struct jffs2_sb_info *c, struct rb_root *list, uint32_t size);
 341 int jffs2_add_older_frag_to_fragtree(struct jffs2_sb_info *c, struct jffs2_inode_info *f, struct jffs2_tmp_dnode_info *tn);
 342 struct jffs2_raw_node_ref *jffs2_link_node_ref(struct jffs2_sb_info *c,
 343                                                struct jffs2_eraseblock *jeb,
 344                                                uint32_t ofs, uint32_t len,
 345                                                struct jffs2_inode_cache *ic);
 346 extern uint32_t __jffs2_ref_totlen(struct jffs2_sb_info *c,
 347                                    struct jffs2_eraseblock *jeb,
 348                                    struct jffs2_raw_node_ref *ref);
 349
 350 /* nodemgmt.c */
 351 int jffs2_thread_should_wake(struct jffs2_sb_info *c);
 352 int jffs2_reserve_space(struct jffs2_sb_info *c, uint32_t minsize,
 353                         uint32_t *len, int prio, uint32_t sumsize);
 354 int jffs2_reserve_space_gc(struct jffs2_sb_info *c, uint32_t minsize,
 355                         uint32_t *len, uint32_t sumsize);
 356 struct jffs2_raw_node_ref *jffs2_add_physical_node_ref(struct jffs2_sb_info *c,
 357                                                        uint32_t ofs, uint32_t len,
 358                                                        struct jffs2_inode_cache *ic);
 359 void jffs2_complete_reservation(struct jffs2_sb_info *c);
 360 void jffs2_mark_node_obsolete(struct jffs2_sb_info *c, struct jffs2_raw_node_ref *raw);
 361
 362 /* write.c */
 363 int jffs2_do_new_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f, uint32_t mode, struct jffs2_raw_inode *ri);
 364
 365 struct jffs2_full_dnode *jffs2_write_dnode(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
 366                                            struct jffs2_raw_inode *ri, const unsigned char *data,
 367                                            uint32_t datalen, int alloc_mode);
 368 struct jffs2_full_dirent *jffs2_write_dirent(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
 369                                              struct jffs2_raw_dirent *rd, const unsigned char *name,
 370                                              uint32_t namelen, int alloc_mode);
 371 int jffs2_write_inode_range(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
 372                             struct jffs2_raw_inode *ri, unsigned char *buf,
 373                             uint32_t offset, uint32_t writelen, uint32_t *retlen);
 374 int jffs2_do_create(struct jffs2_sb_info *c, struct jffs2_inode_info *dir_f, struct jffs2_inode_info *f,
 375                     struct jffs2_raw_inode *ri, const char *name, int namelen);
 376 int jffs2_do_unlink(struct jffs2_sb_info *c, struct jffs2_inode_info *dir_f, const char *name,
 377                     int namelen, struct jffs2_inode_info *dead_f, uint32_t time);
 378 int jffs2_do_link(struct jffs2_sb_info *c, struct jffs2_inode_info *dir_f, uint32_t ino,
 379                    uint8_t type, const char *name, int namelen, uint32_t time);
 380
 381
 382 /* readinode.c */
 383 int jffs2_do_read_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
 384                         uint32_t ino, struct jffs2_raw_inode *latest_node);
 385 int jffs2_do_crccheck_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic);
 386 void jffs2_do_clear_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f);
 387
 388 /* malloc.c */
 389 int jffs2_create_slab_caches(void);
 390 void jffs2_destroy_slab_caches(void);
 391
 392 struct jffs2_full_dirent *jffs2_alloc_full_dirent(int namesize);
 393 void jffs2_free_full_dirent(struct jffs2_full_dirent *);
 394 struct jffs2_full_dnode *jffs2_alloc_full_dnode(void);
 395 void jffs2_free_full_dnode(struct jffs2_full_dnode *);
 396 struct jffs2_raw_dirent *jffs2_alloc_raw_dirent(void);
 397 void jffs2_free_raw_dirent(struct jffs2_raw_dirent *);
 398 struct jffs2_raw_inode *jffs2_alloc_raw_inode(void);
 399 void jffs2_free_raw_inode(struct jffs2_raw_inode *);
 400 struct jffs2_tmp_dnode_info *jffs2_alloc_tmp_dnode_info(void);
 401 void jffs2_free_tmp_dnode_info(struct jffs2_tmp_dnode_info *);
 402 int jffs2_prealloc_raw_node_refs(struct jffs2_sb_info *c,
 403                                  struct jffs2_eraseblock *jeb, int nr);
 404 void jffs2_free_refblock(struct jffs2_raw_node_ref *);
 405 struct jffs2_node_frag *jffs2_alloc_node_frag(void);
 406 void jffs2_free_node_frag(struct jffs2_node_frag *);
 407 struct jffs2_inode_cache *jffs2_alloc_inode_cache(void);
 408 void jffs2_free_inode_cache(struct jffs2_inode_cache *);
 409 #ifdef CONFIG_JFFS2_FS_XATTR
 410 struct jffs2_xattr_datum *jffs2_alloc_xattr_datum(void);
 411 void jffs2_free_xattr_datum(struct jffs2_xattr_datum *);
 412 struct jffs2_xattr_ref *jffs2_alloc_xattr_ref(void);
 413 void jffs2_free_xattr_ref(struct jffs2_xattr_ref *);
 414 #endif
 415
 416 /* gc.c */
 417 int jffs2_garbage_collect_pass(struct jffs2_sb_info *c);
 418
 419 /* read.c */
 420 int jffs2_read_dnode(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
 421                      struct jffs2_full_dnode *fd, unsigned char *buf,
 422                      int ofs, int len);
 423 int jffs2_read_inode_range(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
 424                            unsigned char *buf, uint32_t offset, uint32_t len);
 425 char *jffs2_getlink(struct jffs2_sb_info *c, struct jffs2_inode_info *f);
 426
 427 /* scan.c */
 428 int jffs2_scan_medium(struct jffs2_sb_info *c);
 429 void jffs2_rotate_lists(struct jffs2_sb_info *c);
 430 int jffs2_fill_scan_buf(struct jffs2_sb_info *c, void *buf,
 431                                 uint32_t ofs, uint32_t len);
 432 struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino);
 433 int jffs2_scan_classify_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb);
 434 int jffs2_scan_dirty_space(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, uint32_t size);
 435
 436 /* build.c */
 437 int jffs2_do_mount_fs(struct jffs2_sb_info *c);
 438
 439 /* erase.c */
 440 void jffs2_erase_pending_blocks(struct jffs2_sb_info *c, int count);
 441 void jffs2_free_jeb_node_refs(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb);
 442
 443 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
 444 /* wbuf.c */
 445 int jffs2_flush_wbuf_gc(struct jffs2_sb_info *c, uint32_t ino);
 446 int jffs2_flush_wbuf_pad(struct jffs2_sb_info *c);
 447 int jffs2_check_nand_cleanmarker(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb);
 448 int jffs2_write_nand_cleanmarker(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb);
 449 #endif
 450
 451 #include "debug.h"
 452
 453 #endif /* __JFFS2_NODELIST_H__ */