xref: /linux/drivers/mtd/ubi/ubi.h (revision 2ba9268dd603d23e17643437b2246acb6844953b)
1 /*
2  * Copyright (c) International Business Machines Corp., 2006
3  * Copyright (c) Nokia Corporation, 2006, 2007
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation; either version 2 of the License, or
8  * (at your option) any later version.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
13  * the GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18  *
19  * Author: Artem Bityutskiy (Битюцкий Артём)
20  */
21 
22 #ifndef __UBI_UBI_H__
23 #define __UBI_UBI_H__
24 
25 #include <linux/types.h>
26 #include <linux/list.h>
27 #include <linux/rbtree.h>
28 #include <linux/sched.h>
29 #include <linux/wait.h>
30 #include <linux/mutex.h>
31 #include <linux/rwsem.h>
32 #include <linux/spinlock.h>
33 #include <linux/fs.h>
34 #include <linux/cdev.h>
35 #include <linux/device.h>
36 #include <linux/slab.h>
37 #include <linux/string.h>
38 #include <linux/vmalloc.h>
39 #include <linux/notifier.h>
40 #include <linux/mtd/mtd.h>
41 #include <linux/mtd/ubi.h>
42 #include <asm/pgtable.h>
43 
44 #include "ubi-media.h"
45 
46 /* Maximum number of supported UBI devices */
47 #define UBI_MAX_DEVICES 32
48 
49 /* UBI name used for character devices, sysfs, etc */
50 #define UBI_NAME_STR "ubi"
51 
52 /* Normal UBI messages */
53 #define ubi_msg(ubi, fmt, ...) pr_notice(UBI_NAME_STR "%d: " fmt "\n", \
54 					 ubi->ubi_num, ##__VA_ARGS__)
55 /* UBI warning messages */
56 #define ubi_warn(ubi, fmt, ...) pr_warn(UBI_NAME_STR "%d warning: %s: " fmt "\n", \
57 					ubi->ubi_num, __func__, ##__VA_ARGS__)
58 /* UBI error messages */
59 #define ubi_err(ubi, fmt, ...) pr_err(UBI_NAME_STR "%d error: %s: " fmt "\n", \
60 				      ubi->ubi_num, __func__, ##__VA_ARGS__)
61 
62 /* Background thread name pattern */
63 #define UBI_BGT_NAME_PATTERN "ubi_bgt%dd"
64 
65 /*
66  * This marker in the EBA table means that the LEB is um-mapped.
67  * NOTE! It has to have the same value as %UBI_ALL.
68  */
69 #define UBI_LEB_UNMAPPED -1
70 
71 /*
72  * In case of errors, UBI tries to repeat the operation several times before
73  * returning error. The below constant defines how many times UBI re-tries.
74  */
75 #define UBI_IO_RETRIES 3
76 
77 /*
78  * Length of the protection queue. The length is effectively equivalent to the
79  * number of (global) erase cycles PEBs are protected from the wear-leveling
80  * worker.
81  */
82 #define UBI_PROT_QUEUE_LEN 10
83 
84 /* The volume ID/LEB number/erase counter is unknown */
85 #define UBI_UNKNOWN -1
86 
87 /*
88  * The UBI debugfs directory name pattern and maximum name length (3 for "ubi"
89  * + 2 for the number plus 1 for the trailing zero byte.
90  */
91 #define UBI_DFS_DIR_NAME "ubi%d"
92 #define UBI_DFS_DIR_LEN  (3 + 2 + 1)
93 
94 /*
95  * Error codes returned by the I/O sub-system.
96  *
97  * UBI_IO_FF: the read region of flash contains only 0xFFs
98  * UBI_IO_FF_BITFLIPS: the same as %UBI_IO_FF, but also also there was a data
99  *                     integrity error reported by the MTD driver
100  *                     (uncorrectable ECC error in case of NAND)
101  * UBI_IO_BAD_HDR: the EC or VID header is corrupted (bad magic or CRC)
102  * UBI_IO_BAD_HDR_EBADMSG: the same as %UBI_IO_BAD_HDR, but also there was a
103  *                         data integrity error reported by the MTD driver
104  *                         (uncorrectable ECC error in case of NAND)
105  * UBI_IO_BITFLIPS: bit-flips were detected and corrected
106  *
107  * Note, it is probably better to have bit-flip and ebadmsg as flags which can
108  * be or'ed with other error code. But this is a big change because there are
109  * may callers, so it does not worth the risk of introducing a bug
110  */
111 enum {
112 	UBI_IO_FF = 1,
113 	UBI_IO_FF_BITFLIPS,
114 	UBI_IO_BAD_HDR,
115 	UBI_IO_BAD_HDR_EBADMSG,
116 	UBI_IO_BITFLIPS,
117 };
118 
119 /*
120  * Return codes of the 'ubi_eba_copy_leb()' function.
121  *
122  * MOVE_CANCEL_RACE: canceled because the volume is being deleted, the source
123  *                   PEB was put meanwhile, or there is I/O on the source PEB
124  * MOVE_SOURCE_RD_ERR: canceled because there was a read error from the source
125  *                     PEB
126  * MOVE_TARGET_RD_ERR: canceled because there was a read error from the target
127  *                     PEB
128  * MOVE_TARGET_WR_ERR: canceled because there was a write error to the target
129  *                     PEB
130  * MOVE_TARGET_BITFLIPS: canceled because a bit-flip was detected in the
131  *                       target PEB
132  * MOVE_RETRY: retry scrubbing the PEB
133  */
134 enum {
135 	MOVE_CANCEL_RACE = 1,
136 	MOVE_SOURCE_RD_ERR,
137 	MOVE_TARGET_RD_ERR,
138 	MOVE_TARGET_WR_ERR,
139 	MOVE_TARGET_BITFLIPS,
140 	MOVE_RETRY,
141 };
142 
143 /*
144  * Return codes of the fastmap sub-system
145  *
146  * UBI_NO_FASTMAP: No fastmap super block was found
147  * UBI_BAD_FASTMAP: A fastmap was found but it's unusable
148  */
149 enum {
150 	UBI_NO_FASTMAP = 1,
151 	UBI_BAD_FASTMAP,
152 };
153 
154 /**
155  * struct ubi_wl_entry - wear-leveling entry.
156  * @u.rb: link in the corresponding (free/used) RB-tree
157  * @u.list: link in the protection queue
158  * @ec: erase counter
159  * @pnum: physical eraseblock number
160  *
161  * This data structure is used in the WL sub-system. Each physical eraseblock
162  * has a corresponding &struct wl_entry object which may be kept in different
163  * RB-trees. See WL sub-system for details.
164  */
165 struct ubi_wl_entry {
166 	union {
167 		struct rb_node rb;
168 		struct list_head list;
169 	} u;
170 	int ec;
171 	int pnum;
172 };
173 
174 /**
175  * struct ubi_ltree_entry - an entry in the lock tree.
176  * @rb: links RB-tree nodes
177  * @vol_id: volume ID of the locked logical eraseblock
178  * @lnum: locked logical eraseblock number
179  * @users: how many tasks are using this logical eraseblock or wait for it
180  * @mutex: read/write mutex to implement read/write access serialization to
181  *         the (@vol_id, @lnum) logical eraseblock
182  *
183  * This data structure is used in the EBA sub-system to implement per-LEB
184  * locking. When a logical eraseblock is being locked - corresponding
185  * &struct ubi_ltree_entry object is inserted to the lock tree (@ubi->ltree).
186  * See EBA sub-system for details.
187  */
188 struct ubi_ltree_entry {
189 	struct rb_node rb;
190 	int vol_id;
191 	int lnum;
192 	int users;
193 	struct rw_semaphore mutex;
194 };
195 
196 /**
197  * struct ubi_rename_entry - volume re-name description data structure.
198  * @new_name_len: new volume name length
199  * @new_name: new volume name
200  * @remove: if not zero, this volume should be removed, not re-named
201  * @desc: descriptor of the volume
202  * @list: links re-name entries into a list
203  *
204  * This data structure is utilized in the multiple volume re-name code. Namely,
205  * UBI first creates a list of &struct ubi_rename_entry objects from the
206  * &struct ubi_rnvol_req request object, and then utilizes this list to do all
207  * the job.
208  */
209 struct ubi_rename_entry {
210 	int new_name_len;
211 	char new_name[UBI_VOL_NAME_MAX + 1];
212 	int remove;
213 	struct ubi_volume_desc *desc;
214 	struct list_head list;
215 };
216 
217 struct ubi_volume_desc;
218 
219 /**
220  * struct ubi_fastmap_layout - in-memory fastmap data structure.
221  * @e: PEBs used by the current fastmap
222  * @to_be_tortured: if non-zero tortured this PEB
223  * @used_blocks: number of used PEBs
224  * @max_pool_size: maximal size of the user pool
225  * @max_wl_pool_size: maximal size of the pool used by the WL sub-system
226  */
227 struct ubi_fastmap_layout {
228 	struct ubi_wl_entry *e[UBI_FM_MAX_BLOCKS];
229 	int to_be_tortured[UBI_FM_MAX_BLOCKS];
230 	int used_blocks;
231 	int max_pool_size;
232 	int max_wl_pool_size;
233 };
234 
235 /**
236  * struct ubi_fm_pool - in-memory fastmap pool
237  * @pebs: PEBs in this pool
238  * @used: number of used PEBs
239  * @size: total number of PEBs in this pool
240  * @max_size: maximal size of the pool
241  *
242  * A pool gets filled with up to max_size.
243  * If all PEBs within the pool are used a new fastmap will be written
244  * to the flash and the pool gets refilled with empty PEBs.
245  *
246  */
247 struct ubi_fm_pool {
248 	int pebs[UBI_FM_MAX_POOL_SIZE];
249 	int used;
250 	int size;
251 	int max_size;
252 };
253 
254 /**
255  * struct ubi_volume - UBI volume description data structure.
256  * @dev: device object to make use of the the Linux device model
257  * @cdev: character device object to create character device
258  * @ubi: reference to the UBI device description object
259  * @vol_id: volume ID
260  * @ref_count: volume reference count
261  * @readers: number of users holding this volume in read-only mode
262  * @writers: number of users holding this volume in read-write mode
263  * @exclusive: whether somebody holds this volume in exclusive mode
264  * @metaonly: whether somebody is altering only meta data of this volume
265  *
266  * @reserved_pebs: how many physical eraseblocks are reserved for this volume
267  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
268  * @usable_leb_size: logical eraseblock size without padding
269  * @used_ebs: how many logical eraseblocks in this volume contain data
270  * @last_eb_bytes: how many bytes are stored in the last logical eraseblock
271  * @used_bytes: how many bytes of data this volume contains
272  * @alignment: volume alignment
273  * @data_pad: how many bytes are not used at the end of physical eraseblocks to
274  *            satisfy the requested alignment
275  * @name_len: volume name length
276  * @name: volume name
277  *
278  * @upd_ebs: how many eraseblocks are expected to be updated
279  * @ch_lnum: LEB number which is being changing by the atomic LEB change
280  *           operation
281  * @upd_bytes: how many bytes are expected to be received for volume update or
282  *             atomic LEB change
283  * @upd_received: how many bytes were already received for volume update or
284  *                atomic LEB change
285  * @upd_buf: update buffer which is used to collect update data or data for
286  *           atomic LEB change
287  *
288  * @eba_tbl: EBA table of this volume (LEB->PEB mapping)
289  * @checked: %1 if this static volume was checked
290  * @corrupted: %1 if the volume is corrupted (static volumes only)
291  * @upd_marker: %1 if the update marker is set for this volume
292  * @updating: %1 if the volume is being updated
293  * @changing_leb: %1 if the atomic LEB change ioctl command is in progress
294  * @direct_writes: %1 if direct writes are enabled for this volume
295  *
296  * The @corrupted field indicates that the volume's contents is corrupted.
297  * Since UBI protects only static volumes, this field is not relevant to
298  * dynamic volumes - it is user's responsibility to assure their data
299  * integrity.
300  *
301  * The @upd_marker flag indicates that this volume is either being updated at
302  * the moment or is damaged because of an unclean reboot.
303  */
304 struct ubi_volume {
305 	struct device dev;
306 	struct cdev cdev;
307 	struct ubi_device *ubi;
308 	int vol_id;
309 	int ref_count;
310 	int readers;
311 	int writers;
312 	int exclusive;
313 	int metaonly;
314 
315 	int reserved_pebs;
316 	int vol_type;
317 	int usable_leb_size;
318 	int used_ebs;
319 	int last_eb_bytes;
320 	long long used_bytes;
321 	int alignment;
322 	int data_pad;
323 	int name_len;
324 	char name[UBI_VOL_NAME_MAX + 1];
325 
326 	int upd_ebs;
327 	int ch_lnum;
328 	long long upd_bytes;
329 	long long upd_received;
330 	void *upd_buf;
331 
332 	int *eba_tbl;
333 	unsigned int checked:1;
334 	unsigned int corrupted:1;
335 	unsigned int upd_marker:1;
336 	unsigned int updating:1;
337 	unsigned int changing_leb:1;
338 	unsigned int direct_writes:1;
339 };
340 
341 /**
342  * struct ubi_volume_desc - UBI volume descriptor returned when it is opened.
343  * @vol: reference to the corresponding volume description object
344  * @mode: open mode (%UBI_READONLY, %UBI_READWRITE, %UBI_EXCLUSIVE
345  * or %UBI_METAONLY)
346  */
347 struct ubi_volume_desc {
348 	struct ubi_volume *vol;
349 	int mode;
350 };
351 
352 struct ubi_wl_entry;
353 
354 /**
355  * struct ubi_debug_info - debugging information for an UBI device.
356  *
357  * @chk_gen: if UBI general extra checks are enabled
358  * @chk_io: if UBI I/O extra checks are enabled
359  * @disable_bgt: disable the background task for testing purposes
360  * @emulate_bitflips: emulate bit-flips for testing purposes
361  * @emulate_io_failures: emulate write/erase failures for testing purposes
362  * @dfs_dir_name: name of debugfs directory containing files of this UBI device
363  * @dfs_dir: direntry object of the UBI device debugfs directory
364  * @dfs_chk_gen: debugfs knob to enable UBI general extra checks
365  * @dfs_chk_io: debugfs knob to enable UBI I/O extra checks
366  * @dfs_disable_bgt: debugfs knob to disable the background task
367  * @dfs_emulate_bitflips: debugfs knob to emulate bit-flips
368  * @dfs_emulate_io_failures: debugfs knob to emulate write/erase failures
369  */
370 struct ubi_debug_info {
371 	unsigned int chk_gen:1;
372 	unsigned int chk_io:1;
373 	unsigned int disable_bgt:1;
374 	unsigned int emulate_bitflips:1;
375 	unsigned int emulate_io_failures:1;
376 	char dfs_dir_name[UBI_DFS_DIR_LEN + 1];
377 	struct dentry *dfs_dir;
378 	struct dentry *dfs_chk_gen;
379 	struct dentry *dfs_chk_io;
380 	struct dentry *dfs_disable_bgt;
381 	struct dentry *dfs_emulate_bitflips;
382 	struct dentry *dfs_emulate_io_failures;
383 };
384 
385 /**
386  * struct ubi_device - UBI device description structure
387  * @dev: UBI device object to use the the Linux device model
388  * @cdev: character device object to create character device
389  * @ubi_num: UBI device number
390  * @ubi_name: UBI device name
391  * @vol_count: number of volumes in this UBI device
392  * @volumes: volumes of this UBI device
393  * @volumes_lock: protects @volumes, @rsvd_pebs, @avail_pebs, beb_rsvd_pebs,
394  *                @beb_rsvd_level, @bad_peb_count, @good_peb_count, @vol_count,
395  *                @vol->readers, @vol->writers, @vol->exclusive,
396  *                @vol->metaonly, @vol->ref_count, @vol->mapping and
397  *                @vol->eba_tbl.
398  * @ref_count: count of references on the UBI device
399  * @image_seq: image sequence number recorded on EC headers
400  *
401  * @rsvd_pebs: count of reserved physical eraseblocks
402  * @avail_pebs: count of available physical eraseblocks
403  * @beb_rsvd_pebs: how many physical eraseblocks are reserved for bad PEB
404  *                 handling
405  * @beb_rsvd_level: normal level of PEBs reserved for bad PEB handling
406  *
407  * @autoresize_vol_id: ID of the volume which has to be auto-resized at the end
408  *                     of UBI initialization
409  * @vtbl_slots: how many slots are available in the volume table
410  * @vtbl_size: size of the volume table in bytes
411  * @vtbl: in-RAM volume table copy
412  * @device_mutex: protects on-flash volume table and serializes volume
413  *                creation, deletion, update, re-size, re-name and set
414  *                property
415  *
416  * @max_ec: current highest erase counter value
417  * @mean_ec: current mean erase counter value
418  *
419  * @global_sqnum: global sequence number
420  * @ltree_lock: protects the lock tree and @global_sqnum
421  * @ltree: the lock tree
422  * @alc_mutex: serializes "atomic LEB change" operations
423  *
424  * @fm_disabled: non-zero if fastmap is disabled (default)
425  * @fm: in-memory data structure of the currently used fastmap
426  * @fm_pool: in-memory data structure of the fastmap pool
427  * @fm_wl_pool: in-memory data structure of the fastmap pool used by the WL
428  *		sub-system
429  * @fm_mutex: serializes ubi_update_fastmap() and protects @fm_buf
430  * @fm_buf: vmalloc()'d buffer which holds the raw fastmap
431  * @fm_size: fastmap size in bytes
432  * @fm_sem: allows ubi_update_fastmap() to block EBA table changes
433  * @fm_work: fastmap work queue
434  *
435  * @used: RB-tree of used physical eraseblocks
436  * @erroneous: RB-tree of erroneous used physical eraseblocks
437  * @free: RB-tree of free physical eraseblocks
438  * @free_count: Contains the number of elements in @free
439  * @scrub: RB-tree of physical eraseblocks which need scrubbing
440  * @pq: protection queue (contain physical eraseblocks which are temporarily
441  *      protected from the wear-leveling worker)
442  * @pq_head: protection queue head
443  * @wl_lock: protects the @used, @free, @pq, @pq_head, @lookuptbl, @move_from,
444  *	     @move_to, @move_to_put @erase_pending, @wl_scheduled, @works,
445  *	     @erroneous, and @erroneous_peb_count fields
446  * @move_mutex: serializes eraseblock moves
447  * @work_sem: used to wait for all the scheduled works to finish and prevent
448  * new works from being submitted
449  * @wl_scheduled: non-zero if the wear-leveling was scheduled
450  * @lookuptbl: a table to quickly find a &struct ubi_wl_entry object for any
451  *             physical eraseblock
452  * @move_from: physical eraseblock from where the data is being moved
453  * @move_to: physical eraseblock where the data is being moved to
454  * @move_to_put: if the "to" PEB was put
455  * @works: list of pending works
456  * @works_count: count of pending works
457  * @bgt_thread: background thread description object
458  * @thread_enabled: if the background thread is enabled
459  * @bgt_name: background thread name
460  *
461  * @flash_size: underlying MTD device size (in bytes)
462  * @peb_count: count of physical eraseblocks on the MTD device
463  * @peb_size: physical eraseblock size
464  * @bad_peb_limit: top limit of expected bad physical eraseblocks
465  * @bad_peb_count: count of bad physical eraseblocks
466  * @good_peb_count: count of good physical eraseblocks
467  * @corr_peb_count: count of corrupted physical eraseblocks (preserved and not
468  *                  used by UBI)
469  * @erroneous_peb_count: count of erroneous physical eraseblocks in @erroneous
470  * @max_erroneous: maximum allowed amount of erroneous physical eraseblocks
471  * @min_io_size: minimal input/output unit size of the underlying MTD device
472  * @hdrs_min_io_size: minimal I/O unit size used for VID and EC headers
473  * @ro_mode: if the UBI device is in read-only mode
474  * @leb_size: logical eraseblock size
475  * @leb_start: starting offset of logical eraseblocks within physical
476  *             eraseblocks
477  * @ec_hdr_alsize: size of the EC header aligned to @hdrs_min_io_size
478  * @vid_hdr_alsize: size of the VID header aligned to @hdrs_min_io_size
479  * @vid_hdr_offset: starting offset of the volume identifier header (might be
480  *                  unaligned)
481  * @vid_hdr_aloffset: starting offset of the VID header aligned to
482  * @hdrs_min_io_size
483  * @vid_hdr_shift: contains @vid_hdr_offset - @vid_hdr_aloffset
484  * @bad_allowed: whether the MTD device admits of bad physical eraseblocks or
485  *               not
486  * @nor_flash: non-zero if working on top of NOR flash
487  * @max_write_size: maximum amount of bytes the underlying flash can write at a
488  *                  time (MTD write buffer size)
489  * @mtd: MTD device descriptor
490  *
491  * @peb_buf: a buffer of PEB size used for different purposes
492  * @buf_mutex: protects @peb_buf
493  * @ckvol_mutex: serializes static volume checking when opening
494  *
495  * @dbg: debugging information for this UBI device
496  */
497 struct ubi_device {
498 	struct cdev cdev;
499 	struct device dev;
500 	int ubi_num;
501 	char ubi_name[sizeof(UBI_NAME_STR)+5];
502 	int vol_count;
503 	struct ubi_volume *volumes[UBI_MAX_VOLUMES+UBI_INT_VOL_COUNT];
504 	spinlock_t volumes_lock;
505 	int ref_count;
506 	int image_seq;
507 
508 	int rsvd_pebs;
509 	int avail_pebs;
510 	int beb_rsvd_pebs;
511 	int beb_rsvd_level;
512 	int bad_peb_limit;
513 
514 	int autoresize_vol_id;
515 	int vtbl_slots;
516 	int vtbl_size;
517 	struct ubi_vtbl_record *vtbl;
518 	struct mutex device_mutex;
519 
520 	int max_ec;
521 	/* Note, mean_ec is not updated run-time - should be fixed */
522 	int mean_ec;
523 
524 	/* EBA sub-system's stuff */
525 	unsigned long long global_sqnum;
526 	spinlock_t ltree_lock;
527 	struct rb_root ltree;
528 	struct mutex alc_mutex;
529 
530 	/* Fastmap stuff */
531 	int fm_disabled;
532 	struct ubi_fastmap_layout *fm;
533 	struct ubi_fm_pool fm_pool;
534 	struct ubi_fm_pool fm_wl_pool;
535 	struct rw_semaphore fm_sem;
536 	struct mutex fm_mutex;
537 	void *fm_buf;
538 	size_t fm_size;
539 	struct work_struct fm_work;
540 
541 	/* Wear-leveling sub-system's stuff */
542 	struct rb_root used;
543 	struct rb_root erroneous;
544 	struct rb_root free;
545 	int free_count;
546 	struct rb_root scrub;
547 	struct list_head pq[UBI_PROT_QUEUE_LEN];
548 	int pq_head;
549 	spinlock_t wl_lock;
550 	struct mutex move_mutex;
551 	struct rw_semaphore work_sem;
552 	int wl_scheduled;
553 	struct ubi_wl_entry **lookuptbl;
554 	struct ubi_wl_entry *move_from;
555 	struct ubi_wl_entry *move_to;
556 	int move_to_put;
557 	struct list_head works;
558 	int works_count;
559 	struct task_struct *bgt_thread;
560 	int thread_enabled;
561 	char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];
562 
563 	/* I/O sub-system's stuff */
564 	long long flash_size;
565 	int peb_count;
566 	int peb_size;
567 	int bad_peb_count;
568 	int good_peb_count;
569 	int corr_peb_count;
570 	int erroneous_peb_count;
571 	int max_erroneous;
572 	int min_io_size;
573 	int hdrs_min_io_size;
574 	int ro_mode;
575 	int leb_size;
576 	int leb_start;
577 	int ec_hdr_alsize;
578 	int vid_hdr_alsize;
579 	int vid_hdr_offset;
580 	int vid_hdr_aloffset;
581 	int vid_hdr_shift;
582 	unsigned int bad_allowed:1;
583 	unsigned int nor_flash:1;
584 	int max_write_size;
585 	struct mtd_info *mtd;
586 
587 	void *peb_buf;
588 	struct mutex buf_mutex;
589 	struct mutex ckvol_mutex;
590 
591 	struct ubi_debug_info dbg;
592 };
593 
594 /**
595  * struct ubi_ainf_peb - attach information about a physical eraseblock.
596  * @ec: erase counter (%UBI_UNKNOWN if it is unknown)
597  * @pnum: physical eraseblock number
598  * @vol_id: ID of the volume this LEB belongs to
599  * @lnum: logical eraseblock number
600  * @scrub: if this physical eraseblock needs scrubbing
601  * @copy_flag: this LEB is a copy (@copy_flag is set in VID header of this LEB)
602  * @sqnum: sequence number
603  * @u: unions RB-tree or @list links
604  * @u.rb: link in the per-volume RB-tree of &struct ubi_ainf_peb objects
605  * @u.list: link in one of the eraseblock lists
606  *
607  * One object of this type is allocated for each physical eraseblock when
608  * attaching an MTD device. Note, if this PEB does not belong to any LEB /
609  * volume, the @vol_id and @lnum fields are initialized to %UBI_UNKNOWN.
610  */
611 struct ubi_ainf_peb {
612 	int ec;
613 	int pnum;
614 	int vol_id;
615 	int lnum;
616 	unsigned int scrub:1;
617 	unsigned int copy_flag:1;
618 	unsigned long long sqnum;
619 	union {
620 		struct rb_node rb;
621 		struct list_head list;
622 	} u;
623 };
624 
625 /**
626  * struct ubi_ainf_volume - attaching information about a volume.
627  * @vol_id: volume ID
628  * @highest_lnum: highest logical eraseblock number in this volume
629  * @leb_count: number of logical eraseblocks in this volume
630  * @vol_type: volume type
631  * @used_ebs: number of used logical eraseblocks in this volume (only for
632  *            static volumes)
633  * @last_data_size: amount of data in the last logical eraseblock of this
634  *                  volume (always equivalent to the usable logical eraseblock
635  *                  size in case of dynamic volumes)
636  * @data_pad: how many bytes at the end of logical eraseblocks of this volume
637  *            are not used (due to volume alignment)
638  * @compat: compatibility flags of this volume
639  * @rb: link in the volume RB-tree
640  * @root: root of the RB-tree containing all the eraseblock belonging to this
641  *        volume (&struct ubi_ainf_peb objects)
642  *
643  * One object of this type is allocated for each volume when attaching an MTD
644  * device.
645  */
646 struct ubi_ainf_volume {
647 	int vol_id;
648 	int highest_lnum;
649 	int leb_count;
650 	int vol_type;
651 	int used_ebs;
652 	int last_data_size;
653 	int data_pad;
654 	int compat;
655 	struct rb_node rb;
656 	struct rb_root root;
657 };
658 
659 /**
660  * struct ubi_attach_info - MTD device attaching information.
661  * @volumes: root of the volume RB-tree
662  * @corr: list of corrupted physical eraseblocks
663  * @free: list of free physical eraseblocks
664  * @erase: list of physical eraseblocks which have to be erased
665  * @alien: list of physical eraseblocks which should not be used by UBI (e.g.,
666  *         those belonging to "preserve"-compatible internal volumes)
667  * @corr_peb_count: count of PEBs in the @corr list
668  * @empty_peb_count: count of PEBs which are presumably empty (contain only
669  *                   0xFF bytes)
670  * @alien_peb_count: count of PEBs in the @alien list
671  * @bad_peb_count: count of bad physical eraseblocks
672  * @maybe_bad_peb_count: count of bad physical eraseblocks which are not marked
673  *                       as bad yet, but which look like bad
674  * @vols_found: number of volumes found
675  * @highest_vol_id: highest volume ID
676  * @is_empty: flag indicating whether the MTD device is empty or not
677  * @min_ec: lowest erase counter value
678  * @max_ec: highest erase counter value
679  * @max_sqnum: highest sequence number value
680  * @mean_ec: mean erase counter value
681  * @ec_sum: a temporary variable used when calculating @mean_ec
682  * @ec_count: a temporary variable used when calculating @mean_ec
683  * @aeb_slab_cache: slab cache for &struct ubi_ainf_peb objects
684  *
685  * This data structure contains the result of attaching an MTD device and may
686  * be used by other UBI sub-systems to build final UBI data structures, further
687  * error-recovery and so on.
688  */
689 struct ubi_attach_info {
690 	struct rb_root volumes;
691 	struct list_head corr;
692 	struct list_head free;
693 	struct list_head erase;
694 	struct list_head alien;
695 	int corr_peb_count;
696 	int empty_peb_count;
697 	int alien_peb_count;
698 	int bad_peb_count;
699 	int maybe_bad_peb_count;
700 	int vols_found;
701 	int highest_vol_id;
702 	int is_empty;
703 	int min_ec;
704 	int max_ec;
705 	unsigned long long max_sqnum;
706 	int mean_ec;
707 	uint64_t ec_sum;
708 	int ec_count;
709 	struct kmem_cache *aeb_slab_cache;
710 };
711 
712 /**
713  * struct ubi_work - UBI work description data structure.
714  * @list: a link in the list of pending works
715  * @func: worker function
716  * @e: physical eraseblock to erase
717  * @vol_id: the volume ID on which this erasure is being performed
718  * @lnum: the logical eraseblock number
719  * @torture: if the physical eraseblock has to be tortured
720  * @anchor: produce a anchor PEB to by used by fastmap
721  *
722  * The @func pointer points to the worker function. If the @shutdown argument is
723  * not zero, the worker has to free the resources and exit immediately as the
724  * WL sub-system is shutting down.
725  * The worker has to return zero in case of success and a negative error code in
726  * case of failure.
727  */
728 struct ubi_work {
729 	struct list_head list;
730 	int (*func)(struct ubi_device *ubi, struct ubi_work *wrk, int shutdown);
731 	/* The below fields are only relevant to erasure works */
732 	struct ubi_wl_entry *e;
733 	int vol_id;
734 	int lnum;
735 	int torture;
736 	int anchor;
737 };
738 
739 #include "debug.h"
740 
741 extern struct kmem_cache *ubi_wl_entry_slab;
742 extern const struct file_operations ubi_ctrl_cdev_operations;
743 extern const struct file_operations ubi_cdev_operations;
744 extern const struct file_operations ubi_vol_cdev_operations;
745 extern struct class *ubi_class;
746 extern struct mutex ubi_devices_mutex;
747 extern struct blocking_notifier_head ubi_notifiers;
748 
749 /* attach.c */
750 int ubi_add_to_av(struct ubi_device *ubi, struct ubi_attach_info *ai, int pnum,
751 		  int ec, const struct ubi_vid_hdr *vid_hdr, int bitflips);
752 struct ubi_ainf_volume *ubi_find_av(const struct ubi_attach_info *ai,
753 				    int vol_id);
754 void ubi_remove_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av);
755 struct ubi_ainf_peb *ubi_early_get_peb(struct ubi_device *ubi,
756 				       struct ubi_attach_info *ai);
757 int ubi_attach(struct ubi_device *ubi, int force_scan);
758 void ubi_destroy_ai(struct ubi_attach_info *ai);
759 
760 /* vtbl.c */
761 int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
762 			   struct ubi_vtbl_record *vtbl_rec);
763 int ubi_vtbl_rename_volumes(struct ubi_device *ubi,
764 			    struct list_head *rename_list);
765 int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_attach_info *ai);
766 
767 /* vmt.c */
768 int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req);
769 int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl);
770 int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs);
771 int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list);
772 int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol);
773 void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol);
774 
775 /* upd.c */
776 int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
777 		     long long bytes);
778 int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
779 			 const void __user *buf, int count);
780 int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
781 			 const struct ubi_leb_change_req *req);
782 int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
783 			     const void __user *buf, int count);
784 
785 /* misc.c */
786 int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,
787 		      int length);
788 int ubi_check_volume(struct ubi_device *ubi, int vol_id);
789 void ubi_update_reserved(struct ubi_device *ubi);
790 void ubi_calculate_reserved(struct ubi_device *ubi);
791 int ubi_check_pattern(const void *buf, uint8_t patt, int size);
792 
793 /* eba.c */
794 int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
795 		      int lnum);
796 int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
797 		     void *buf, int offset, int len, int check);
798 int ubi_eba_read_leb_sg(struct ubi_device *ubi, struct ubi_volume *vol,
799 			struct ubi_sgl *sgl, int lnum, int offset, int len,
800 			int check);
801 int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
802 		      const void *buf, int offset, int len);
803 int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
804 			 int lnum, const void *buf, int len, int used_ebs);
805 int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
806 			      int lnum, const void *buf, int len);
807 int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
808 		     struct ubi_vid_hdr *vid_hdr);
809 int ubi_eba_init(struct ubi_device *ubi, struct ubi_attach_info *ai);
810 unsigned long long ubi_next_sqnum(struct ubi_device *ubi);
811 int self_check_eba(struct ubi_device *ubi, struct ubi_attach_info *ai_fastmap,
812 		   struct ubi_attach_info *ai_scan);
813 
814 /* wl.c */
815 int ubi_wl_get_peb(struct ubi_device *ubi);
816 int ubi_wl_put_peb(struct ubi_device *ubi, int vol_id, int lnum,
817 		   int pnum, int torture);
818 int ubi_wl_flush(struct ubi_device *ubi, int vol_id, int lnum);
819 int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum);
820 int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai);
821 void ubi_wl_close(struct ubi_device *ubi);
822 int ubi_thread(void *u);
823 struct ubi_wl_entry *ubi_wl_get_fm_peb(struct ubi_device *ubi, int anchor);
824 int ubi_wl_put_fm_peb(struct ubi_device *ubi, struct ubi_wl_entry *used_e,
825 		      int lnum, int torture);
826 int ubi_is_erase_work(struct ubi_work *wrk);
827 void ubi_refill_pools(struct ubi_device *ubi);
828 int ubi_ensure_anchor_pebs(struct ubi_device *ubi);
829 
830 /* io.c */
831 int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
832 		int len);
833 int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
834 		 int len);
835 int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture);
836 int ubi_io_is_bad(const struct ubi_device *ubi, int pnum);
837 int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum);
838 int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
839 		       struct ubi_ec_hdr *ec_hdr, int verbose);
840 int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
841 			struct ubi_ec_hdr *ec_hdr);
842 int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
843 			struct ubi_vid_hdr *vid_hdr, int verbose);
844 int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
845 			 struct ubi_vid_hdr *vid_hdr);
846 
847 /* build.c */
848 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
849 		       int vid_hdr_offset, int max_beb_per1024);
850 int ubi_detach_mtd_dev(int ubi_num, int anyway);
851 struct ubi_device *ubi_get_device(int ubi_num);
852 void ubi_put_device(struct ubi_device *ubi);
853 struct ubi_device *ubi_get_by_major(int major);
854 int ubi_major2num(int major);
855 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol,
856 		      int ntype);
857 int ubi_notify_all(struct ubi_device *ubi, int ntype,
858 		   struct notifier_block *nb);
859 int ubi_enumerate_volumes(struct notifier_block *nb);
860 void ubi_free_internal_volumes(struct ubi_device *ubi);
861 
862 /* kapi.c */
863 void ubi_do_get_device_info(struct ubi_device *ubi, struct ubi_device_info *di);
864 void ubi_do_get_volume_info(struct ubi_device *ubi, struct ubi_volume *vol,
865 			    struct ubi_volume_info *vi);
866 /* scan.c */
867 int ubi_compare_lebs(struct ubi_device *ubi, const struct ubi_ainf_peb *aeb,
868 		      int pnum, const struct ubi_vid_hdr *vid_hdr);
869 
870 /* fastmap.c */
871 size_t ubi_calc_fm_size(struct ubi_device *ubi);
872 int ubi_update_fastmap(struct ubi_device *ubi);
873 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
874 		     int fm_anchor);
875 
876 /* block.c */
877 #ifdef CONFIG_MTD_UBI_BLOCK
878 int ubiblock_init(void);
879 void ubiblock_exit(void);
880 int ubiblock_create(struct ubi_volume_info *vi);
881 int ubiblock_remove(struct ubi_volume_info *vi);
882 #else
883 static inline int ubiblock_init(void) { return 0; }
884 static inline void ubiblock_exit(void) {}
885 static inline int ubiblock_create(struct ubi_volume_info *vi)
886 {
887 	return -ENOSYS;
888 }
889 static inline int ubiblock_remove(struct ubi_volume_info *vi)
890 {
891 	return -ENOSYS;
892 }
893 #endif
894 
895 
896 /*
897  * ubi_rb_for_each_entry - walk an RB-tree.
898  * @rb: a pointer to type 'struct rb_node' to use as a loop counter
899  * @pos: a pointer to RB-tree entry type to use as a loop counter
900  * @root: RB-tree's root
901  * @member: the name of the 'struct rb_node' within the RB-tree entry
902  */
903 #define ubi_rb_for_each_entry(rb, pos, root, member)                         \
904 	for (rb = rb_first(root),                                            \
905 	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL);     \
906 	     rb;                                                             \
907 	     rb = rb_next(rb),                                               \
908 	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL))
909 
910 /*
911  * ubi_move_aeb_to_list - move a PEB from the volume tree to a list.
912  *
913  * @av: volume attaching information
914  * @aeb: attaching eraseblock information
915  * @list: the list to move to
916  */
917 static inline void ubi_move_aeb_to_list(struct ubi_ainf_volume *av,
918 					 struct ubi_ainf_peb *aeb,
919 					 struct list_head *list)
920 {
921 		rb_erase(&aeb->u.rb, &av->root);
922 		list_add_tail(&aeb->u.list, list);
923 }
924 
925 /**
926  * ubi_zalloc_vid_hdr - allocate a volume identifier header object.
927  * @ubi: UBI device description object
928  * @gfp_flags: GFP flags to allocate with
929  *
930  * This function returns a pointer to the newly allocated and zero-filled
931  * volume identifier header object in case of success and %NULL in case of
932  * failure.
933  */
934 static inline struct ubi_vid_hdr *
935 ubi_zalloc_vid_hdr(const struct ubi_device *ubi, gfp_t gfp_flags)
936 {
937 	void *vid_hdr;
938 
939 	vid_hdr = kzalloc(ubi->vid_hdr_alsize, gfp_flags);
940 	if (!vid_hdr)
941 		return NULL;
942 
943 	/*
944 	 * VID headers may be stored at un-aligned flash offsets, so we shift
945 	 * the pointer.
946 	 */
947 	return vid_hdr + ubi->vid_hdr_shift;
948 }
949 
950 /**
951  * ubi_free_vid_hdr - free a volume identifier header object.
952  * @ubi: UBI device description object
953  * @vid_hdr: the object to free
954  */
955 static inline void ubi_free_vid_hdr(const struct ubi_device *ubi,
956 				    struct ubi_vid_hdr *vid_hdr)
957 {
958 	void *p = vid_hdr;
959 
960 	if (!p)
961 		return;
962 
963 	kfree(p - ubi->vid_hdr_shift);
964 }
965 
966 /*
967  * This function is equivalent to 'ubi_io_read()', but @offset is relative to
968  * the beginning of the logical eraseblock, not to the beginning of the
969  * physical eraseblock.
970  */
971 static inline int ubi_io_read_data(const struct ubi_device *ubi, void *buf,
972 				   int pnum, int offset, int len)
973 {
974 	ubi_assert(offset >= 0);
975 	return ubi_io_read(ubi, buf, pnum, offset + ubi->leb_start, len);
976 }
977 
978 /*
979  * This function is equivalent to 'ubi_io_write()', but @offset is relative to
980  * the beginning of the logical eraseblock, not to the beginning of the
981  * physical eraseblock.
982  */
983 static inline int ubi_io_write_data(struct ubi_device *ubi, const void *buf,
984 				    int pnum, int offset, int len)
985 {
986 	ubi_assert(offset >= 0);
987 	return ubi_io_write(ubi, buf, pnum, offset + ubi->leb_start, len);
988 }
989 
990 /**
991  * ubi_ro_mode - switch to read-only mode.
992  * @ubi: UBI device description object
993  */
994 static inline void ubi_ro_mode(struct ubi_device *ubi)
995 {
996 	if (!ubi->ro_mode) {
997 		ubi->ro_mode = 1;
998 		ubi_warn(ubi, "switch to read-only mode");
999 		dump_stack();
1000 	}
1001 }
1002 
1003 /**
1004  * vol_id2idx - get table index by volume ID.
1005  * @ubi: UBI device description object
1006  * @vol_id: volume ID
1007  */
1008 static inline int vol_id2idx(const struct ubi_device *ubi, int vol_id)
1009 {
1010 	if (vol_id >= UBI_INTERNAL_VOL_START)
1011 		return vol_id - UBI_INTERNAL_VOL_START + ubi->vtbl_slots;
1012 	else
1013 		return vol_id;
1014 }
1015 
1016 /**
1017  * idx2vol_id - get volume ID by table index.
1018  * @ubi: UBI device description object
1019  * @idx: table index
1020  */
1021 static inline int idx2vol_id(const struct ubi_device *ubi, int idx)
1022 {
1023 	if (idx >= ubi->vtbl_slots)
1024 		return idx - ubi->vtbl_slots + UBI_INTERNAL_VOL_START;
1025 	else
1026 		return idx;
1027 }
1028 
1029 #endif /* !__UBI_UBI_H__ */
1030