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| author | NeilBrown <neilb@cse.unsw.edu.au> | 2005-09-09 16:23:45 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-09-09 16:39:10 -0700 |
| commit | 8ddf9efe6708f3674f0ddfeb6425fd27bea109a2 (patch) | |
| tree | 90862c8fa9f04cf98423b3da1b2c5d1f01a7310d /include | |
| parent | 36fa30636fb84b209210299684e1be66d9e58217 (diff) | |
| download | linux-8ddf9efe6708f3674f0ddfeb6425fd27bea109a2.tar.gz linux-8ddf9efe6708f3674f0ddfeb6425fd27bea109a2.tar.bz2 linux-8ddf9efe6708f3674f0ddfeb6425fd27bea109a2.zip | |
[PATCH] md: support write-mostly device in raid1
This allows a device in a raid1 to be marked as "write mostly". Read requests
will only be sent if there is no other option.
Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/raid/md_k.h | 3 | ||||
| -rw-r--r-- | include/linux/raid/md_p.h | 11 |
2 files changed, 12 insertions, 2 deletions
diff --git a/include/linux/raid/md_k.h b/include/linux/raid/md_k.h index 817062bf7352..7ef78e15ce04 100644 --- a/include/linux/raid/md_k.h +++ b/include/linux/raid/md_k.h @@ -181,6 +181,9 @@ struct mdk_rdev_s int faulty; /* if faulty do not issue IO requests */ int in_sync; /* device is a full member of the array */ + unsigned long flags; /* Should include faulty and in_sync here. */ +#define WriteMostly 4 /* Avoid reading if at all possible */ + int desc_nr; /* descriptor index in the superblock */ int raid_disk; /* role of device in array */ int saved_raid_disk; /* role that device used to have in the diff --git a/include/linux/raid/md_p.h b/include/linux/raid/md_p.h index dc65cd435494..4f047f84fb1f 100644 --- a/include/linux/raid/md_p.h +++ b/include/linux/raid/md_p.h @@ -79,6 +79,11 @@ #define MD_DISK_SYNC 2 /* disk is in sync with the raid set */ #define MD_DISK_REMOVED 3 /* disk is in sync with the raid set */ +#define MD_DISK_WRITEMOSTLY 9 /* disk is "write-mostly" is RAID1 config. + * read requests will only be sent here in + * dire need + */ + typedef struct mdp_device_descriptor_s { __u32 number; /* 0 Device number in the entire set */ __u32 major; /* 1 Device major number */ @@ -193,7 +198,7 @@ struct mdp_superblock_1 { __u64 ctime; /* lo 40 bits are seconds, top 24 are microseconds or 0*/ __u32 level; /* -4 (multipath), -1 (linear), 0,1,4,5 */ - __u32 layout; /* only for raid5 currently */ + __u32 layout; /* only for raid5 and raid10 currently */ __u64 size; /* used size of component devices, in 512byte sectors */ __u32 chunksize; /* in 512byte sectors */ @@ -212,7 +217,9 @@ struct mdp_superblock_1 { __u32 dev_number; /* permanent identifier of this device - not role in raid */ __u32 cnt_corrected_read; /* number of read errors that were corrected by re-writing */ __u8 device_uuid[16]; /* user-space setable, ignored by kernel */ - __u8 pad2[64-56]; /* set to 0 when writing */ + __u8 devflags; /* per-device flags. Only one defined...*/ +#define WriteMostly1 1 /* mask for writemostly flag in above */ + __u8 pad2[64-57]; /* set to 0 when writing */ /* array state information - 64 bytes */ __u64 utime; /* 40 bits second, 24 btes microseconds */ |