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authorNeilBrown <neilb@suse.de>2006-01-06 03:20:36 -0500
committerLinus Torvalds <torvalds@g5.osdl.org>2006-01-06 11:34:06 -0500
commit2604b703b6b3db80e3c75ce472a54dfd0b7bf9f4 (patch)
tree8c0e985c455ff35af24fbe60d8a3f5a276034370 /include/linux
parenta24a8dd858e0ba50f06a9fd8f61fe8c4fe7a8d8e (diff)
[PATCH] md: remove personality numbering from md
md supports multiple different RAID level, each being implemented by a 'personality' (which is often in a separate module). These personalities have fairly artificial 'numbers'. The numbers are use to: 1- provide an index into an array where the various personalities are recorded 2- identify the module (via an alias) which implements are particular personality. Neither of these uses really justify the existence of personality numbers. The array can be replaced by a linked list which is searched (array lookup only happens very rarely). Module identification can be done using an alias based on level rather than 'personality' number. The current 'raid5' modules support two level (4 and 5) but only one personality. This slight awkwardness (which was handled in the mapping from level to personality) can be better handled by allowing raid5 to register 2 personalities. With this change in place, the core md module does not need to have an exhaustive list of all possible personalities, so other personalities can be added independently. This patch also moves the check for chunksize being non-zero into the ->run routines for the personalities that need it, rather than having it in core-md. This has a side effect of allowing 'faulty' and 'linear' not to have a chunk-size set. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/raid/md.h4
-rw-r--r--include/linux/raid/md_k.h63
2 files changed, 12 insertions, 55 deletions
diff --git a/include/linux/raid/md.h b/include/linux/raid/md.h
index 13e7c4b6236..b6e0bcad84e 100644
--- a/include/linux/raid/md.h
+++ b/include/linux/raid/md.h
@@ -71,8 +71,8 @@
71 */ 71 */
72#define MD_PATCHLEVEL_VERSION 3 72#define MD_PATCHLEVEL_VERSION 3
73 73
74extern int register_md_personality (int p_num, mdk_personality_t *p); 74extern int register_md_personality (struct mdk_personality *p);
75extern int unregister_md_personality (int p_num); 75extern int unregister_md_personality (struct mdk_personality *p);
76extern mdk_thread_t * md_register_thread (void (*run) (mddev_t *mddev), 76extern mdk_thread_t * md_register_thread (void (*run) (mddev_t *mddev),
77 mddev_t *mddev, const char *name); 77 mddev_t *mddev, const char *name);
78extern void md_unregister_thread (mdk_thread_t *thread); 78extern void md_unregister_thread (mdk_thread_t *thread);
diff --git a/include/linux/raid/md_k.h b/include/linux/raid/md_k.h
index 1dd587b5975..e559fb701aa 100644
--- a/include/linux/raid/md_k.h
+++ b/include/linux/raid/md_k.h
@@ -18,62 +18,19 @@
18/* and dm-bio-list.h is not under include/linux because.... ??? */ 18/* and dm-bio-list.h is not under include/linux because.... ??? */
19#include "../../../drivers/md/dm-bio-list.h" 19#include "../../../drivers/md/dm-bio-list.h"
20 20
21#define MD_RESERVED 0UL
22#define LINEAR 1UL
23#define RAID0 2UL
24#define RAID1 3UL
25#define RAID5 4UL
26#define TRANSLUCENT 5UL
27#define HSM 6UL
28#define MULTIPATH 7UL
29#define RAID6 8UL
30#define RAID10 9UL
31#define FAULTY 10UL
32#define MAX_PERSONALITY 11UL
33
34#define LEVEL_MULTIPATH (-4) 21#define LEVEL_MULTIPATH (-4)
35#define LEVEL_LINEAR (-1) 22#define LEVEL_LINEAR (-1)
36#define LEVEL_FAULTY (-5) 23#define LEVEL_FAULTY (-5)
37 24
25/* we need a value for 'no level specified' and 0
26 * means 'raid0', so we need something else. This is
27 * for internal use only
28 */
29#define LEVEL_NONE (-1000000)
30
38#define MaxSector (~(sector_t)0) 31#define MaxSector (~(sector_t)0)
39#define MD_THREAD_NAME_MAX 14 32#define MD_THREAD_NAME_MAX 14
40 33
41static inline int pers_to_level (int pers)
42{
43 switch (pers) {
44 case FAULTY: return LEVEL_FAULTY;
45 case MULTIPATH: return LEVEL_MULTIPATH;
46 case HSM: return -3;
47 case TRANSLUCENT: return -2;
48 case LINEAR: return LEVEL_LINEAR;
49 case RAID0: return 0;
50 case RAID1: return 1;
51 case RAID5: return 5;
52 case RAID6: return 6;
53 case RAID10: return 10;
54 }
55 BUG();
56 return MD_RESERVED;
57}
58
59static inline int level_to_pers (int level)
60{
61 switch (level) {
62 case LEVEL_FAULTY: return FAULTY;
63 case LEVEL_MULTIPATH: return MULTIPATH;
64 case -3: return HSM;
65 case -2: return TRANSLUCENT;
66 case LEVEL_LINEAR: return LINEAR;
67 case 0: return RAID0;
68 case 1: return RAID1;
69 case 4:
70 case 5: return RAID5;
71 case 6: return RAID6;
72 case 10: return RAID10;
73 }
74 return MD_RESERVED;
75}
76
77typedef struct mddev_s mddev_t; 34typedef struct mddev_s mddev_t;
78typedef struct mdk_rdev_s mdk_rdev_t; 35typedef struct mdk_rdev_s mdk_rdev_t;
79 36
@@ -140,12 +97,10 @@ struct mdk_rdev_s
140 */ 97 */
141}; 98};
142 99
143typedef struct mdk_personality_s mdk_personality_t;
144
145struct mddev_s 100struct mddev_s
146{ 101{
147 void *private; 102 void *private;
148 mdk_personality_t *pers; 103 struct mdk_personality *pers;
149 dev_t unit; 104 dev_t unit;
150 int md_minor; 105 int md_minor;
151 struct list_head disks; 106 struct list_head disks;
@@ -266,9 +221,11 @@ static inline void md_sync_acct(struct block_device *bdev, unsigned long nr_sect
266 atomic_add(nr_sectors, &bdev->bd_contains->bd_disk->sync_io); 221 atomic_add(nr_sectors, &bdev->bd_contains->bd_disk->sync_io);
267} 222}
268 223
269struct mdk_personality_s 224struct mdk_personality
270{ 225{
271 char *name; 226 char *name;
227 int level;
228 struct list_head list;
272 struct module *owner; 229 struct module *owner;
273 int (*make_request)(request_queue_t *q, struct bio *bio); 230 int (*make_request)(request_queue_t *q, struct bio *bio);
274 int (*run)(mddev_t *mddev); 231 int (*run)(mddev_t *mddev);