Root/fs/jffs2/nodelist.h

1/*
2 * JFFS2 -- Journalling Flash File System, Version 2.
3 *
4 * Copyright © 2001-2007 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 */
11
12#ifndef __JFFS2_NODELIST_H__
13#define __JFFS2_NODELIST_H__
14
15#include <linux/fs.h>
16#include <linux/types.h>
17#include <linux/jffs2.h>
18#include "jffs2_fs_sb.h"
19#include "jffs2_fs_i.h"
20#include "xattr.h"
21#include "acl.h"
22#include "summary.h"
23
24#ifdef __ECOS
25#include "os-ecos.h"
26#else
27#include <linux/mtd/compatmac.h> /* For compatibility with older kernels */
28#include "os-linux.h"
29#endif
30
31#define JFFS2_NATIVE_ENDIAN
32
33/* Note we handle mode bits conversion from JFFS2 (i.e. Linux) to/from
34   whatever OS we're actually running on here too. */
35
36#if defined(JFFS2_NATIVE_ENDIAN)
37#define cpu_to_je16(x) ((jint16_t){x})
38#define cpu_to_je32(x) ((jint32_t){x})
39#define cpu_to_jemode(x) ((jmode_t){os_to_jffs2_mode(x)})
40
41#define constant_cpu_to_je16(x) ((jint16_t){x})
42#define constant_cpu_to_je32(x) ((jint32_t){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 constant_cpu_to_je16(x) ((jint16_t){__constant_cpu_to_be16(x)})
53#define constant_cpu_to_je32(x) ((jint32_t){__constant_cpu_to_be32(x)})
54
55#define je16_to_cpu(x) (be16_to_cpu(x.v16))
56#define je32_to_cpu(x) (be32_to_cpu(x.v32))
57#define jemode_to_cpu(x) (be32_to_cpu(jffs2_to_os_mode((x).m)))
58#elif defined(JFFS2_LITTLE_ENDIAN)
59#define cpu_to_je16(x) ((jint16_t){cpu_to_le16(x)})
60#define cpu_to_je32(x) ((jint32_t){cpu_to_le32(x)})
61#define cpu_to_jemode(x) ((jmode_t){cpu_to_le32(os_to_jffs2_mode(x))})
62
63#define constant_cpu_to_je16(x) ((jint16_t){__constant_cpu_to_le16(x)})
64#define constant_cpu_to_je32(x) ((jint32_t){__constant_cpu_to_le32(x)})
65
66#define je16_to_cpu(x) (le16_to_cpu(x.v16))
67#define je32_to_cpu(x) (le32_to_cpu(x.v32))
68#define jemode_to_cpu(x) (le32_to_cpu(jffs2_to_os_mode((x).m)))
69#else
70#error wibble
71#endif
72
73/* The minimal node header size */
74#define JFFS2_MIN_NODE_HEADER sizeof(struct jffs2_raw_dirent)
75
76/*
77  This is all we need to keep in-core for each raw node during normal
78  operation. As and when we do read_inode on a particular inode, we can
79  scan the nodes which are listed for it and build up a proper map of
80  which nodes are currently valid. JFFSv1 always used to keep that whole
81  map in core for each inode.
82*/
83struct jffs2_raw_node_ref
84{
85    struct jffs2_raw_node_ref *next_in_ino; /* Points to the next raw_node_ref
86        for this object. If this _is_ the last, it points to the inode_cache,
87        xattr_ref or xattr_datum instead. The common part of those structures
88        has NULL in the first word. See jffs2_raw_ref_to_ic() below */
89    uint32_t flash_offset;
90#undef TEST_TOTLEN
91#ifdef TEST_TOTLEN
92    uint32_t __totlen; /* This may die; use ref_totlen(c, jeb, ) below */
93#endif
94};
95
96#define REF_LINK_NODE ((int32_t)-1)
97#define REF_EMPTY_NODE ((int32_t)-2)
98
99/* Use blocks of about 256 bytes */
100#define REFS_PER_BLOCK ((255/sizeof(struct jffs2_raw_node_ref))-1)
101
102static inline struct jffs2_raw_node_ref *ref_next(struct jffs2_raw_node_ref *ref)
103{
104    ref++;
105
106    /* Link to another block of refs */
107    if (ref->flash_offset == REF_LINK_NODE) {
108        ref = ref->next_in_ino;
109        if (!ref)
110            return ref;
111    }
112
113    /* End of chain */
114    if (ref->flash_offset == REF_EMPTY_NODE)
115        return NULL;
116
117    return ref;
118}
119
120static inline struct jffs2_inode_cache *jffs2_raw_ref_to_ic(struct jffs2_raw_node_ref *raw)
121{
122    while(raw->next_in_ino)
123        raw = raw->next_in_ino;
124
125    /* NB. This can be a jffs2_xattr_datum or jffs2_xattr_ref and
126       not actually a jffs2_inode_cache. Check ->class */
127    return ((struct jffs2_inode_cache *)raw);
128}
129
130    /* flash_offset & 3 always has to be zero, because nodes are
131       always aligned at 4 bytes. So we have a couple of extra bits
132       to play with, which indicate the node's status; see below: */
133#define REF_UNCHECKED 0 /* We haven't yet checked the CRC or built its inode */
134#define REF_OBSOLETE 1 /* Obsolete, can be completely ignored */
135#define REF_PRISTINE 2 /* Completely clean. GC without looking */
136#define REF_NORMAL 3 /* Possibly overlapped. Read the page and write again on GC */
137#define ref_flags(ref) ((ref)->flash_offset & 3)
138#define ref_offset(ref) ((ref)->flash_offset & ~3)
139#define ref_obsolete(ref) (((ref)->flash_offset & 3) == REF_OBSOLETE)
140#define mark_ref_normal(ref) do { (ref)->flash_offset = ref_offset(ref) | REF_NORMAL; } while(0)
141
142/* Dirent nodes should be REF_PRISTINE only if they are not a deletion
143   dirent. Deletion dirents should be REF_NORMAL so that GC gets to
144   throw them away when appropriate */
145#define dirent_node_state(rd) ( (je32_to_cpu((rd)->ino)?REF_PRISTINE:REF_NORMAL) )
146
147/* NB: REF_PRISTINE for an inode-less node (ref->next_in_ino == NULL) indicates
148   it is an unknown node of type JFFS2_NODETYPE_RWCOMPAT_COPY, so it'll get
149   copied. If you need to do anything different to GC inode-less nodes, then
150   you need to modify gc.c accordingly. */
151
152/* For each inode in the filesystem, we need to keep a record of
153   nlink, because it would be a PITA to scan the whole directory tree
154   at read_inode() time to calculate it, and to keep sufficient information
155   in the raw_node_ref (basically both parent and child inode number for
156   dirent nodes) would take more space than this does. We also keep
157   a pointer to the first physical node which is part of this inode, too.
158*/
159struct jffs2_inode_cache {
160    /* First part of structure is shared with other objects which
161       can terminate the raw node refs' next_in_ino list -- which
162       currently struct jffs2_xattr_datum and struct jffs2_xattr_ref. */
163
164    struct jffs2_full_dirent *scan_dents; /* Used during scan to hold
165        temporary lists of dirents, and later must be set to
166        NULL to mark the end of the raw_node_ref->next_in_ino
167        chain. */
168    struct jffs2_raw_node_ref *nodes;
169    uint8_t class; /* It's used for identification */
170
171    /* end of shared structure */
172
173    uint8_t flags;
174    uint16_t state;
175    uint32_t ino;
176    struct jffs2_inode_cache *next;
177#ifdef CONFIG_JFFS2_FS_XATTR
178    struct jffs2_xattr_ref *xref;
179#endif
180    uint32_t pino_nlink; /* Directories store parent inode
181                   here; other inodes store nlink.
182                   Zero always means that it's
183                   completely unlinked. */
184};
185
186/* Inode states for 'state' above. We need the 'GC' state to prevent
187   someone from doing a read_inode() while we're moving a 'REF_PRISTINE'
188   node without going through all the iget() nonsense */
189#define INO_STATE_UNCHECKED 0 /* CRC checks not yet done */
190#define INO_STATE_CHECKING 1 /* CRC checks in progress */
191#define INO_STATE_PRESENT 2 /* In core */
192#define INO_STATE_CHECKEDABSENT 3 /* Checked, cleared again */
193#define INO_STATE_GC 4 /* GCing a 'pristine' node */
194#define INO_STATE_READING 5 /* In read_inode() */
195#define INO_STATE_CLEARING 6 /* In clear_inode() */
196
197#define INO_FLAGS_XATTR_CHECKED 0x01 /* has no duplicate xattr_ref */
198
199#define RAWNODE_CLASS_INODE_CACHE 0
200#define RAWNODE_CLASS_XATTR_DATUM 1
201#define RAWNODE_CLASS_XATTR_REF 2
202
203#define INOCACHE_HASHSIZE 128
204
205#define write_ofs(c) ((c)->nextblock->offset + (c)->sector_size - (c)->nextblock->free_size)
206
207/*
208  Larger representation of a raw node, kept in-core only when the
209  struct inode for this particular ino is instantiated.
210*/
211
212struct jffs2_full_dnode
213{
214    struct jffs2_raw_node_ref *raw;
215    uint32_t ofs; /* The offset to which the data of this node belongs */
216    uint32_t size;
217    uint32_t frags; /* Number of fragments which currently refer
218            to this node. When this reaches zero,
219            the node is obsolete. */
220};
221
222/*
223   Even larger representation of a raw node, kept in-core only while
224   we're actually building up the original map of which nodes go where,
225   in read_inode()
226*/
227struct jffs2_tmp_dnode_info
228{
229    struct rb_node rb;
230    struct jffs2_full_dnode *fn;
231    uint32_t version;
232    uint32_t data_crc;
233    uint32_t partial_crc;
234    uint16_t csize;
235    uint16_t overlapped;
236};
237
238/* Temporary data structure used during readinode. */
239struct jffs2_readinode_info
240{
241    struct rb_root tn_root;
242    struct jffs2_tmp_dnode_info *mdata_tn;
243    uint32_t highest_version;
244    uint32_t latest_mctime;
245    uint32_t mctime_ver;
246    struct jffs2_full_dirent *fds;
247    struct jffs2_raw_node_ref *latest_ref;
248};
249
250struct jffs2_full_dirent
251{
252    struct jffs2_raw_node_ref *raw;
253    struct jffs2_full_dirent *next;
254    uint32_t version;
255    uint32_t ino; /* == zero for unlink */
256    unsigned int nhash;
257    unsigned char type;
258    unsigned char name[0];
259};
260
261/*
262  Fragments - used to build a map of which raw node to obtain
263  data from for each part of the ino
264*/
265struct jffs2_node_frag
266{
267    struct rb_node rb;
268    struct jffs2_full_dnode *node; /* NULL for holes */
269    uint32_t size;
270    uint32_t ofs; /* The offset to which this fragment belongs */
271};
272
273struct jffs2_eraseblock
274{
275    struct list_head list;
276    int bad_count;
277    uint32_t offset; /* of this block in the MTD */
278
279    uint32_t unchecked_size;
280    uint32_t used_size;
281    uint32_t dirty_size;
282    uint32_t wasted_size;
283    uint32_t free_size; /* Note that sector_size - free_size
284                   is the address of the first free space */
285    uint32_t allocated_refs;
286    struct jffs2_raw_node_ref *first_node;
287    struct jffs2_raw_node_ref *last_node;
288
289    struct jffs2_raw_node_ref *gc_node; /* Next node to be garbage collected */
290};
291
292static inline int jffs2_blocks_use_vmalloc(struct jffs2_sb_info *c)
293{
294    return ((c->flash_size / c->sector_size) * sizeof (struct jffs2_eraseblock)) > (128 * 1024);
295}
296
297#define ref_totlen(a, b, c) __jffs2_ref_totlen((a), (b), (c))
298
299#define ALLOC_NORMAL 0 /* Normal allocation */
300#define ALLOC_DELETION 1 /* Deletion node. Best to allow it */
301#define ALLOC_GC 2 /* Space requested for GC. Give it or die */
302#define ALLOC_NORETRY 3 /* For jffs2_write_dnode: On failure, return -EAGAIN instead of retrying */
303
304/* How much dirty space before it goes on the very_dirty_list */
305#define VERYDIRTY(c, size) ((size) >= ((c)->sector_size / 2))
306
307/* check if dirty space is more than 255 Byte */
308#define ISDIRTY(size) ((size) > sizeof (struct jffs2_raw_inode) + JFFS2_MIN_DATA_LEN)
309
310#define PAD(x) (((x)+3)&~3)
311
312static inline int jffs2_encode_dev(union jffs2_device_node *jdev, dev_t rdev)
313{
314    if (old_valid_dev(rdev)) {
315        jdev->old = cpu_to_je16(old_encode_dev(rdev));
316        return sizeof(jdev->old);
317    } else {
318        jdev->new = cpu_to_je32(new_encode_dev(rdev));
319        return sizeof(jdev->new);
320    }
321}
322
323static inline struct jffs2_node_frag *frag_first(struct rb_root *root)
324{
325    struct rb_node *node = rb_first(root);
326
327    if (!node)
328        return NULL;
329
330    return rb_entry(node, struct jffs2_node_frag, rb);
331}
332
333static inline struct jffs2_node_frag *frag_last(struct rb_root *root)
334{
335    struct rb_node *node = rb_last(root);
336
337    if (!node)
338        return NULL;
339
340    return rb_entry(node, struct jffs2_node_frag, rb);
341}
342
343#define frag_next(frag) rb_entry(rb_next(&(frag)->rb), struct jffs2_node_frag, rb)
344#define frag_prev(frag) rb_entry(rb_prev(&(frag)->rb), struct jffs2_node_frag, rb)
345#define frag_parent(frag) rb_entry(rb_parent(&(frag)->rb), struct jffs2_node_frag, rb)
346#define frag_left(frag) rb_entry((frag)->rb.rb_left, struct jffs2_node_frag, rb)
347#define frag_right(frag) rb_entry((frag)->rb.rb_right, struct jffs2_node_frag, rb)
348#define frag_erase(frag, list) rb_erase(&frag->rb, list);
349
350#define tn_next(tn) rb_entry(rb_next(&(tn)->rb), struct jffs2_tmp_dnode_info, rb)
351#define tn_prev(tn) rb_entry(rb_prev(&(tn)->rb), struct jffs2_tmp_dnode_info, rb)
352#define tn_parent(tn) rb_entry(rb_parent(&(tn)->rb), struct jffs2_tmp_dnode_info, rb)
353#define tn_left(tn) rb_entry((tn)->rb.rb_left, struct jffs2_tmp_dnode_info, rb)
354#define tn_right(tn) rb_entry((tn)->rb.rb_right, struct jffs2_tmp_dnode_info, rb)
355#define tn_erase(tn, list) rb_erase(&tn->rb, list);
356#define tn_last(list) rb_entry(rb_last(list), struct jffs2_tmp_dnode_info, rb)
357#define tn_first(list) rb_entry(rb_first(list), struct jffs2_tmp_dnode_info, rb)
358
359/* nodelist.c */
360void jffs2_add_fd_to_list(struct jffs2_sb_info *c, struct jffs2_full_dirent *new, struct jffs2_full_dirent **list);
361void jffs2_set_inocache_state(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic, int state);
362struct jffs2_inode_cache *jffs2_get_ino_cache(struct jffs2_sb_info *c, uint32_t ino);
363void jffs2_add_ino_cache (struct jffs2_sb_info *c, struct jffs2_inode_cache *new);
364void jffs2_del_ino_cache(struct jffs2_sb_info *c, struct jffs2_inode_cache *old);
365void jffs2_free_ino_caches(struct jffs2_sb_info *c);
366void jffs2_free_raw_node_refs(struct jffs2_sb_info *c);
367struct jffs2_node_frag *jffs2_lookup_node_frag(struct rb_root *fragtree, uint32_t offset);
368void jffs2_kill_fragtree(struct rb_root *root, struct jffs2_sb_info *c_delete);
369int jffs2_add_full_dnode_to_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f, struct jffs2_full_dnode *fn);
370uint32_t jffs2_truncate_fragtree (struct jffs2_sb_info *c, struct rb_root *list, uint32_t size);
371struct jffs2_raw_node_ref *jffs2_link_node_ref(struct jffs2_sb_info *c,
372                           struct jffs2_eraseblock *jeb,
373                           uint32_t ofs, uint32_t len,
374                           struct jffs2_inode_cache *ic);
375extern uint32_t __jffs2_ref_totlen(struct jffs2_sb_info *c,
376                   struct jffs2_eraseblock *jeb,
377                   struct jffs2_raw_node_ref *ref);
378
379/* nodemgmt.c */
380int jffs2_thread_should_wake(struct jffs2_sb_info *c);
381int jffs2_reserve_space(struct jffs2_sb_info *c, uint32_t minsize,
382            uint32_t *len, int prio, uint32_t sumsize);
383int jffs2_reserve_space_gc(struct jffs2_sb_info *c, uint32_t minsize,
384            uint32_t *len, uint32_t sumsize);
385struct jffs2_raw_node_ref *jffs2_add_physical_node_ref(struct jffs2_sb_info *c,
386                               uint32_t ofs, uint32_t len,
387                               struct jffs2_inode_cache *ic);
388void jffs2_complete_reservation(struct jffs2_sb_info *c);
389void jffs2_mark_node_obsolete(struct jffs2_sb_info *c, struct jffs2_raw_node_ref *raw);
390
391/* write.c */
392int jffs2_do_new_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f, uint32_t mode, struct jffs2_raw_inode *ri);
393
394struct jffs2_full_dnode *jffs2_write_dnode(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
395                       struct jffs2_raw_inode *ri, const unsigned char *data,
396                       uint32_t datalen, int alloc_mode);
397struct jffs2_full_dirent *jffs2_write_dirent(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
398                         struct jffs2_raw_dirent *rd, const unsigned char *name,
399                         uint32_t namelen, int alloc_mode);
400int jffs2_write_inode_range(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
401                struct jffs2_raw_inode *ri, unsigned char *buf,
402                uint32_t offset, uint32_t writelen, uint32_t *retlen);
403int jffs2_do_create(struct jffs2_sb_info *c, struct jffs2_inode_info *dir_f, struct jffs2_inode_info *f,
404            struct jffs2_raw_inode *ri, const char *name, int namelen);
405int jffs2_do_unlink(struct jffs2_sb_info *c, struct jffs2_inode_info *dir_f, const char *name,
406            int namelen, struct jffs2_inode_info *dead_f, uint32_t time);
407int jffs2_do_link(struct jffs2_sb_info *c, struct jffs2_inode_info *dir_f, uint32_t ino,
408           uint8_t type, const char *name, int namelen, uint32_t time);
409
410
411/* readinode.c */
412int jffs2_do_read_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
413            uint32_t ino, struct jffs2_raw_inode *latest_node);
414int jffs2_do_crccheck_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic);
415void jffs2_do_clear_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f);
416
417/* malloc.c */
418int jffs2_create_slab_caches(void);
419void jffs2_destroy_slab_caches(void);
420
421struct jffs2_full_dirent *jffs2_alloc_full_dirent(int namesize);
422void jffs2_free_full_dirent(struct jffs2_full_dirent *);
423struct jffs2_full_dnode *jffs2_alloc_full_dnode(void);
424void jffs2_free_full_dnode(struct jffs2_full_dnode *);
425struct jffs2_raw_dirent *jffs2_alloc_raw_dirent(void);
426void jffs2_free_raw_dirent(struct jffs2_raw_dirent *);
427struct jffs2_raw_inode *jffs2_alloc_raw_inode(void);
428void jffs2_free_raw_inode(struct jffs2_raw_inode *);
429struct jffs2_tmp_dnode_info *jffs2_alloc_tmp_dnode_info(void);
430void jffs2_free_tmp_dnode_info(struct jffs2_tmp_dnode_info *);
431int jffs2_prealloc_raw_node_refs(struct jffs2_sb_info *c,
432                 struct jffs2_eraseblock *jeb, int nr);
433void jffs2_free_refblock(struct jffs2_raw_node_ref *);
434struct jffs2_node_frag *jffs2_alloc_node_frag(void);
435void jffs2_free_node_frag(struct jffs2_node_frag *);
436struct jffs2_inode_cache *jffs2_alloc_inode_cache(void);
437void jffs2_free_inode_cache(struct jffs2_inode_cache *);
438#ifdef CONFIG_JFFS2_FS_XATTR
439struct jffs2_xattr_datum *jffs2_alloc_xattr_datum(void);
440void jffs2_free_xattr_datum(struct jffs2_xattr_datum *);
441struct jffs2_xattr_ref *jffs2_alloc_xattr_ref(void);
442void jffs2_free_xattr_ref(struct jffs2_xattr_ref *);
443#endif
444
445/* gc.c */
446int jffs2_garbage_collect_pass(struct jffs2_sb_info *c);
447
448/* read.c */
449int jffs2_read_dnode(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
450             struct jffs2_full_dnode *fd, unsigned char *buf,
451             int ofs, int len);
452int jffs2_read_inode_range(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
453               unsigned char *buf, uint32_t offset, uint32_t len);
454char *jffs2_getlink(struct jffs2_sb_info *c, struct jffs2_inode_info *f);
455
456/* scan.c */
457int jffs2_scan_medium(struct jffs2_sb_info *c);
458void jffs2_rotate_lists(struct jffs2_sb_info *c);
459struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino);
460int jffs2_scan_classify_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb);
461int jffs2_scan_dirty_space(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, uint32_t size);
462
463/* build.c */
464int jffs2_do_mount_fs(struct jffs2_sb_info *c);
465
466/* erase.c */
467void jffs2_erase_pending_blocks(struct jffs2_sb_info *c, int count);
468void jffs2_free_jeb_node_refs(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb);
469
470#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
471/* wbuf.c */
472int jffs2_flush_wbuf_gc(struct jffs2_sb_info *c, uint32_t ino);
473int jffs2_flush_wbuf_pad(struct jffs2_sb_info *c);
474int jffs2_check_nand_cleanmarker(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb);
475int jffs2_write_nand_cleanmarker(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb);
476#endif
477
478#include "debug.h"
479
480#endif /* __JFFS2_NODELIST_H__ */
481

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