From a654b9d8f851f4ca02649d5825cbe6c608adb10c Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 21 Jun 2005 17:17:27 -0700 Subject: [PATCH] md: allow md intent bitmap to be stored near the superblock. This provides an alternate to storing the bitmap in a separate file. The bitmap can be stored at a given offset from the superblock. Obviously the creator of the array must make sure this doesn't intersect with data.... After is good for version-0.90 superblocks. Signed-off-by: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/raid/bitmap.h | 2 ++ include/linux/raid/md.h | 15 ++++++++++++++- include/linux/raid/md_k.h | 4 ++++ include/linux/raid/md_p.h | 7 ++++++- 4 files changed, 26 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/raid/bitmap.h b/include/linux/raid/bitmap.h index cfe60cf..e24b74b 100644 --- a/include/linux/raid/bitmap.h +++ b/include/linux/raid/bitmap.h @@ -217,6 +217,7 @@ struct bitmap { /* bitmap spinlock */ spinlock_t lock; + long offset; /* offset from superblock if file is NULL */ struct file *file; /* backing disk file */ struct page *sb_page; /* cached copy of the bitmap file superblock */ struct page **filemap; /* list of cache pages for the file */ @@ -255,6 +256,7 @@ void bitmap_print_sb(struct bitmap *bitmap); int bitmap_update_sb(struct bitmap *bitmap); int bitmap_setallbits(struct bitmap *bitmap); +void bitmap_write_all(struct bitmap *bitmap); /* these are exported */ int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors); diff --git a/include/linux/raid/md.h b/include/linux/raid/md.h index 75f41d8..ffa316c 100644 --- a/include/linux/raid/md.h +++ b/include/linux/raid/md.h @@ -60,7 +60,14 @@ */ #define MD_MAJOR_VERSION 0 #define MD_MINOR_VERSION 90 -#define MD_PATCHLEVEL_VERSION 1 +/* + * MD_PATCHLEVEL_VERSION indicates kernel functionality. + * >=1 means different superblock formats are selectable using SET_ARRAY_INFO + * and major_version/minor_version accordingly + * >=2 means that Internal bitmaps are supported by setting MD_SB_BITMAP_PRESENT + * in the super status byte + */ +#define MD_PATCHLEVEL_VERSION 2 extern int register_md_personality (int p_num, mdk_personality_t *p); extern int unregister_md_personality (int p_num); @@ -78,6 +85,12 @@ extern void md_unplug_mddev(mddev_t *mddev); extern void md_print_devices (void); +extern void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev, + sector_t sector, int size, struct page *page); +extern int sync_page_io(struct block_device *bdev, sector_t sector, int size, + struct page *page, int rw); + + #define MD_BUG(x...) { printk("md: bug in file %s, line %d\n", __FILE__, __LINE__); md_print_devices(); } #endif diff --git a/include/linux/raid/md_k.h b/include/linux/raid/md_k.h index 3e97702..a3725b5 100644 --- a/include/linux/raid/md_k.h +++ b/include/linux/raid/md_k.h @@ -273,6 +273,10 @@ struct mddev_s struct bitmap *bitmap; /* the bitmap for the device */ struct file *bitmap_file; /* the bitmap file */ + long bitmap_offset; /* offset from superblock of + * start of bitmap. May be + * negative, but not '0' + */ struct list_head all_mddevs; }; diff --git a/include/linux/raid/md_p.h b/include/linux/raid/md_p.h index 8ba95d6..8e592a2 100644 --- a/include/linux/raid/md_p.h +++ b/include/linux/raid/md_p.h @@ -96,6 +96,7 @@ typedef struct mdp_device_descriptor_s { #define MD_SB_CLEAN 0 #define MD_SB_ERRORS 1 +#define MD_SB_BITMAP_PRESENT 8 /* bitmap may be present nearby */ typedef struct mdp_superblock_s { /* * Constant generic information @@ -184,7 +185,7 @@ struct mdp_superblock_1 { /* constant array information - 128 bytes */ __u32 magic; /* MD_SB_MAGIC: 0xa92b4efc - little endian */ __u32 major_version; /* 1 */ - __u32 feature_map; /* 0 for now */ + __u32 feature_map; /* bit 0 set if 'bitmap_offset' is meaningful */ __u32 pad0; /* always set to 0 when writing */ __u8 set_uuid[16]; /* user-space generated. */ @@ -197,6 +198,10 @@ struct mdp_superblock_1 { __u32 chunksize; /* in 512byte sectors */ __u32 raid_disks; + __u32 bitmap_offset; /* sectors after start of superblock that bitmap starts + * NOTE: signed, so bitmap can be before superblock + * only meaningful of feature_map[0] is set. + */ __u8 pad1[128-96]; /* set to 0 when written */ /* constant this-device information - 64 bytes */ -- cgit v1.1