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-rw-r--r--include/linux/raid/bitmap.h280
-rw-r--r--include/linux/raid/md_k.h4
-rw-r--r--include/linux/raid/md_u.h7
3 files changed, 291 insertions, 0 deletions
diff --git a/include/linux/raid/bitmap.h b/include/linux/raid/bitmap.h
new file mode 100644
index 000000000000..f785cf26cbad
--- /dev/null
+++ b/include/linux/raid/bitmap.h
@@ -0,0 +1,280 @@
1/*
2 * bitmap.h: Copyright (C) Peter T. Breuer (ptb@ot.uc3m.es) 2003
3 *
4 * additions: Copyright (C) 2003-2004, Paul Clements, SteelEye Technology, Inc.
5 */
6#ifndef BITMAP_H
7#define BITMAP_H 1
8
9#define BITMAP_MAJOR 3
10#define BITMAP_MINOR 38
11
12/*
13 * in-memory bitmap:
14 *
15 * Use 16 bit block counters to track pending writes to each "chunk".
16 * The 2 high order bits are special-purpose, the first is a flag indicating
17 * whether a resync is needed. The second is a flag indicating whether a
18 * resync is active.
19 * This means that the counter is actually 14 bits:
20 *
21 * +--------+--------+------------------------------------------------+
22 * | resync | resync | counter |
23 * | needed | active | |
24 * | (0-1) | (0-1) | (0-16383) |
25 * +--------+--------+------------------------------------------------+
26 *
27 * The "resync needed" bit is set when:
28 * a '1' bit is read from storage at startup.
29 * a write request fails on some drives
30 * a resync is aborted on a chunk with 'resync active' set
31 * It is cleared (and resync-active set) when a resync starts across all drives
32 * of the chunk.
33 *
34 *
35 * The "resync active" bit is set when:
36 * a resync is started on all drives, and resync_needed is set.
37 * resync_needed will be cleared (as long as resync_active wasn't already set).
38 * It is cleared when a resync completes.
39 *
40 * The counter counts pending write requests, plus the on-disk bit.
41 * When the counter is '1' and the resync bits are clear, the on-disk
42 * bit can be cleared aswell, thus setting the counter to 0.
43 * When we set a bit, or in the counter (to start a write), if the fields is
44 * 0, we first set the disk bit and set the counter to 1.
45 *
46 * If the counter is 0, the on-disk bit is clear and the stipe is clean
47 * Anything that dirties the stipe pushes the counter to 2 (at least)
48 * and sets the on-disk bit (lazily).
49 * If a periodic sweep find the counter at 2, it is decremented to 1.
50 * If the sweep find the counter at 1, the on-disk bit is cleared and the
51 * counter goes to zero.
52 *
53 * Also, we'll hijack the "map" pointer itself and use it as two 16 bit block
54 * counters as a fallback when "page" memory cannot be allocated:
55 *
56 * Normal case (page memory allocated):
57 *
58 * page pointer (32-bit)
59 *
60 * [ ] ------+
61 * |
62 * +-------> [ ][ ]..[ ] (4096 byte page == 2048 counters)
63 * c1 c2 c2048
64 *
65 * Hijacked case (page memory allocation failed):
66 *
67 * hijacked page pointer (32-bit)
68 *
69 * [ ][ ] (no page memory allocated)
70 * counter #1 (16-bit) counter #2 (16-bit)
71 *
72 */
73
74#ifdef __KERNEL__
75
76#define PAGE_BITS (PAGE_SIZE << 3)
77#define PAGE_BIT_SHIFT (PAGE_SHIFT + 3)
78
79typedef __u16 bitmap_counter_t;
80#define COUNTER_BITS 16
81#define COUNTER_BIT_SHIFT 4
82#define COUNTER_BYTE_RATIO (COUNTER_BITS / 8)
83#define COUNTER_BYTE_SHIFT (COUNTER_BIT_SHIFT - 3)
84
85#define NEEDED_MASK ((bitmap_counter_t) (1 << (COUNTER_BITS - 1)))
86#define RESYNC_MASK ((bitmap_counter_t) (1 << (COUNTER_BITS - 2)))
87#define COUNTER_MAX ((bitmap_counter_t) RESYNC_MASK - 1)
88#define NEEDED(x) (((bitmap_counter_t) x) & NEEDED_MASK)
89#define RESYNC(x) (((bitmap_counter_t) x) & RESYNC_MASK)
90#define COUNTER(x) (((bitmap_counter_t) x) & COUNTER_MAX)
91
92/* how many counters per page? */
93#define PAGE_COUNTER_RATIO (PAGE_BITS / COUNTER_BITS)
94/* same, except a shift value for more efficient bitops */
95#define PAGE_COUNTER_SHIFT (PAGE_BIT_SHIFT - COUNTER_BIT_SHIFT)
96/* same, except a mask value for more efficient bitops */
97#define PAGE_COUNTER_MASK (PAGE_COUNTER_RATIO - 1)
98
99#define BITMAP_BLOCK_SIZE 512
100#define BITMAP_BLOCK_SHIFT 9
101
102/* how many blocks per chunk? (this is variable) */
103#define CHUNK_BLOCK_RATIO(bitmap) ((bitmap)->chunksize >> BITMAP_BLOCK_SHIFT)
104#define CHUNK_BLOCK_SHIFT(bitmap) ((bitmap)->chunkshift - BITMAP_BLOCK_SHIFT)
105#define CHUNK_BLOCK_MASK(bitmap) (CHUNK_BLOCK_RATIO(bitmap) - 1)
106
107/* when hijacked, the counters and bits represent even larger "chunks" */
108/* there will be 1024 chunks represented by each counter in the page pointers */
109#define PAGEPTR_BLOCK_RATIO(bitmap) \
110 (CHUNK_BLOCK_RATIO(bitmap) << PAGE_COUNTER_SHIFT >> 1)
111#define PAGEPTR_BLOCK_SHIFT(bitmap) \
112 (CHUNK_BLOCK_SHIFT(bitmap) + PAGE_COUNTER_SHIFT - 1)
113#define PAGEPTR_BLOCK_MASK(bitmap) (PAGEPTR_BLOCK_RATIO(bitmap) - 1)
114
115/*
116 * on-disk bitmap:
117 *
118 * Use one bit per "chunk" (block set). We do the disk I/O on the bitmap
119 * file a page at a time. There's a superblock at the start of the file.
120 */
121
122/* map chunks (bits) to file pages - offset by the size of the superblock */
123#define CHUNK_BIT_OFFSET(chunk) ((chunk) + (sizeof(bitmap_super_t) << 3))
124
125#endif
126
127/*
128 * bitmap structures:
129 */
130
131#define BITMAP_MAGIC 0x6d746962
132
133/* use these for bitmap->flags and bitmap->sb->state bit-fields */
134enum bitmap_state {
135 BITMAP_ACTIVE = 0x001, /* the bitmap is in use */
136 BITMAP_STALE = 0x002 /* the bitmap file is out of date or had -EIO */
137};
138
139/* the superblock at the front of the bitmap file -- little endian */
140typedef struct bitmap_super_s {
141 __u32 magic; /* 0 BITMAP_MAGIC */
142 __u32 version; /* 4 the bitmap major for now, could change... */
143 __u8 uuid[16]; /* 8 128 bit uuid - must match md device uuid */
144 __u64 events; /* 24 event counter for the bitmap (1)*/
145 __u64 events_cleared;/*32 event counter when last bit cleared (2) */
146 __u64 sync_size; /* 40 the size of the md device's sync range(3) */
147 __u32 state; /* 48 bitmap state information */
148 __u32 chunksize; /* 52 the bitmap chunk size in bytes */
149 __u32 daemon_sleep; /* 56 seconds between disk flushes */
150
151 __u8 pad[256 - 60]; /* set to zero */
152} bitmap_super_t;
153
154/* notes:
155 * (1) This event counter is updated before the eventcounter in the md superblock
156 * When a bitmap is loaded, it is only accepted if this event counter is equal
157 * to, or one greater than, the event counter in the superblock.
158 * (2) This event counter is updated when the other one is *if*and*only*if* the
159 * array is not degraded. As bits are not cleared when the array is degraded,
160 * this represents the last time that any bits were cleared.
161 * If a device is being added that has an event count with this value or
162 * higher, it is accepted as conforming to the bitmap.
163 * (3)This is the number of sectors represented by the bitmap, and is the range that
164 * resync happens across. For raid1 and raid5/6 it is the size of individual
165 * devices. For raid10 it is the size of the array.
166 */
167
168#ifdef __KERNEL__
169
170/* the in-memory bitmap is represented by bitmap_pages */
171struct bitmap_page {
172 /*
173 * map points to the actual memory page
174 */
175 char *map;
176 /*
177 * in emergencies (when map cannot be alloced), hijack the map
178 * pointer and use it as two counters itself
179 */
180 unsigned int hijacked:1;
181 /*
182 * count of dirty bits on the page
183 */
184 unsigned int count:31;
185};
186
187/* keep track of bitmap file pages that have pending writes on them */
188struct page_list {
189 struct list_head list;
190 struct page *page;
191};
192
193/* the main bitmap structure - one per mddev */
194struct bitmap {
195 struct bitmap_page *bp;
196 unsigned long pages; /* total number of pages in the bitmap */
197 unsigned long missing_pages; /* number of pages not yet allocated */
198
199 mddev_t *mddev; /* the md device that the bitmap is for */
200
201 int counter_bits; /* how many bits per block counter */
202
203 /* bitmap chunksize -- how much data does each bit represent? */
204 unsigned long chunksize;
205 unsigned long chunkshift; /* chunksize = 2^chunkshift (for bitops) */
206 unsigned long chunks; /* total number of data chunks for the array */
207
208 /* We hold a count on the chunk currently being synced, and drop
209 * it when the last block is started. If the resync is aborted
210 * midway, we need to be able to drop that count, so we remember
211 * the counted chunk..
212 */
213 unsigned long syncchunk;
214
215 __u64 events_cleared;
216
217 /* bitmap spinlock */
218 spinlock_t lock;
219
220 struct file *file; /* backing disk file */
221 struct page *sb_page; /* cached copy of the bitmap file superblock */
222 struct page **filemap; /* list of cache pages for the file */
223 unsigned long *filemap_attr; /* attributes associated w/ filemap pages */
224 unsigned long file_pages; /* number of pages in the file */
225
226 unsigned long flags;
227
228 /*
229 * the bitmap daemon - periodically wakes up and sweeps the bitmap
230 * file, cleaning up bits and flushing out pages to disk as necessary
231 */
232 unsigned long daemon_lastrun; /* jiffies of last run */
233 unsigned long daemon_sleep; /* how many seconds between updates? */
234
235 /*
236 * bitmap write daemon - this daemon performs writes to the bitmap file
237 * this thread is only needed because of a limitation in ext3 (jbd)
238 * that does not allow a task to have two journal transactions ongoing
239 * simultaneously (even if the transactions are for two different
240 * filesystems) -- in the case of bitmap, that would be the filesystem
241 * that the bitmap file resides on and the filesystem that is mounted
242 * on the md device -- see current->journal_info in jbd/transaction.c
243 */
244 mdk_thread_t *writeback_daemon;
245 spinlock_t write_lock;
246 struct semaphore write_ready;
247 struct semaphore write_done;
248 unsigned long writes_pending;
249 wait_queue_head_t write_wait;
250 struct list_head write_pages;
251 struct list_head complete_pages;
252 mempool_t *write_pool;
253};
254
255/* the bitmap API */
256
257/* these are used only by md/bitmap */
258int bitmap_create(mddev_t *mddev);
259void bitmap_destroy(mddev_t *mddev);
260int bitmap_active(struct bitmap *bitmap);
261
262char *file_path(struct file *file, char *buf, int count);
263void bitmap_print_sb(struct bitmap *bitmap);
264int bitmap_update_sb(struct bitmap *bitmap);
265
266int bitmap_setallbits(struct bitmap *bitmap);
267
268/* these are exported */
269int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors);
270void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors,
271 int success);
272int bitmap_start_sync(struct bitmap *bitmap, sector_t offset, int *blocks);
273void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, int *blocks, int aborted);
274void bitmap_close_sync(struct bitmap *bitmap);
275
276int bitmap_unplug(struct bitmap *bitmap);
277int bitmap_daemon_work(struct bitmap *bitmap);
278#endif
279
280#endif
diff --git a/include/linux/raid/md_k.h b/include/linux/raid/md_k.h
index bce0032decff..16e94a9f0f8c 100644
--- a/include/linux/raid/md_k.h
+++ b/include/linux/raid/md_k.h
@@ -267,6 +267,9 @@ struct mddev_s
267 atomic_t writes_pending; 267 atomic_t writes_pending;
268 request_queue_t *queue; /* for plugging ... */ 268 request_queue_t *queue; /* for plugging ... */
269 269
270 struct bitmap *bitmap; /* the bitmap for the device */
271 struct file *bitmap_file; /* the bitmap file */
272
270 struct list_head all_mddevs; 273 struct list_head all_mddevs;
271}; 274};
272 275
@@ -341,6 +344,7 @@ typedef struct mdk_thread_s {
341 unsigned long flags; 344 unsigned long flags;
342 struct completion *event; 345 struct completion *event;
343 struct task_struct *tsk; 346 struct task_struct *tsk;
347 unsigned long timeout;
344 const char *name; 348 const char *name;
345} mdk_thread_t; 349} mdk_thread_t;
346 350
diff --git a/include/linux/raid/md_u.h b/include/linux/raid/md_u.h
index a2df5c2a42af..81da20ccec4d 100644
--- a/include/linux/raid/md_u.h
+++ b/include/linux/raid/md_u.h
@@ -23,6 +23,7 @@
23#define GET_DISK_INFO _IOR (MD_MAJOR, 0x12, mdu_disk_info_t) 23#define GET_DISK_INFO _IOR (MD_MAJOR, 0x12, mdu_disk_info_t)
24#define PRINT_RAID_DEBUG _IO (MD_MAJOR, 0x13) 24#define PRINT_RAID_DEBUG _IO (MD_MAJOR, 0x13)
25#define RAID_AUTORUN _IO (MD_MAJOR, 0x14) 25#define RAID_AUTORUN _IO (MD_MAJOR, 0x14)
26#define GET_BITMAP_FILE _IOR (MD_MAJOR, 0x15, mdu_bitmap_file_t)
26 27
27/* configuration */ 28/* configuration */
28#define CLEAR_ARRAY _IO (MD_MAJOR, 0x20) 29#define CLEAR_ARRAY _IO (MD_MAJOR, 0x20)
@@ -36,6 +37,7 @@
36#define HOT_ADD_DISK _IO (MD_MAJOR, 0x28) 37#define HOT_ADD_DISK _IO (MD_MAJOR, 0x28)
37#define SET_DISK_FAULTY _IO (MD_MAJOR, 0x29) 38#define SET_DISK_FAULTY _IO (MD_MAJOR, 0x29)
38#define HOT_GENERATE_ERROR _IO (MD_MAJOR, 0x2a) 39#define HOT_GENERATE_ERROR _IO (MD_MAJOR, 0x2a)
40#define SET_BITMAP_FILE _IOW (MD_MAJOR, 0x2b, int)
39 41
40/* usage */ 42/* usage */
41#define RUN_ARRAY _IOW (MD_MAJOR, 0x30, mdu_param_t) 43#define RUN_ARRAY _IOW (MD_MAJOR, 0x30, mdu_param_t)
@@ -106,6 +108,11 @@ typedef struct mdu_start_info_s {
106 108
107} mdu_start_info_t; 109} mdu_start_info_t;
108 110
111typedef struct mdu_bitmap_file_s
112{
113 char pathname[4096];
114} mdu_bitmap_file_t;
115
109typedef struct mdu_param_s 116typedef struct mdu_param_s
110{ 117{
111 int personality; /* 1,2,3,4 */ 118 int personality; /* 1,2,3,4 */