diff options
Diffstat (limited to 'include/linux/raid')
-rw-r--r-- | include/linux/raid/bitmap.h | 280 | ||||
-rw-r--r-- | include/linux/raid/md_k.h | 4 | ||||
-rw-r--r-- | include/linux/raid/md_u.h | 7 |
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 | |||
79 | typedef __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 */ | ||
134 | enum 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 */ | ||
140 | typedef 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 */ | ||
171 | struct 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 */ | ||
188 | struct page_list { | ||
189 | struct list_head list; | ||
190 | struct page *page; | ||
191 | }; | ||
192 | |||
193 | /* the main bitmap structure - one per mddev */ | ||
194 | struct 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 */ | ||
258 | int bitmap_create(mddev_t *mddev); | ||
259 | void bitmap_destroy(mddev_t *mddev); | ||
260 | int bitmap_active(struct bitmap *bitmap); | ||
261 | |||
262 | char *file_path(struct file *file, char *buf, int count); | ||
263 | void bitmap_print_sb(struct bitmap *bitmap); | ||
264 | int bitmap_update_sb(struct bitmap *bitmap); | ||
265 | |||
266 | int bitmap_setallbits(struct bitmap *bitmap); | ||
267 | |||
268 | /* these are exported */ | ||
269 | int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors); | ||
270 | void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, | ||
271 | int success); | ||
272 | int bitmap_start_sync(struct bitmap *bitmap, sector_t offset, int *blocks); | ||
273 | void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, int *blocks, int aborted); | ||
274 | void bitmap_close_sync(struct bitmap *bitmap); | ||
275 | |||
276 | int bitmap_unplug(struct bitmap *bitmap); | ||
277 | int 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 | ||
111 | typedef struct mdu_bitmap_file_s | ||
112 | { | ||
113 | char pathname[4096]; | ||
114 | } mdu_bitmap_file_t; | ||
115 | |||
109 | typedef struct mdu_param_s | 116 | typedef struct mdu_param_s |
110 | { | 117 | { |
111 | int personality; /* 1,2,3,4 */ | 118 | int personality; /* 1,2,3,4 */ |