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MD: support initial bitmap creation in-kernel

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Add bitmap support to the device-mapper specific metadata area.

This patch allows the creation of the bitmap metadata area upon
initial array creation via device-mapper.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
This commit is contained in:
Jonathan Brassow 2011-06-08 17:59:30 -05:00 committed by NeilBrown
parent 076f968b37
commit 9c81075f43
2 changed files with 89 additions and 5 deletions
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93
drivers/md/bitmap.c
View File

@ -534,6 +534,82 @@ void bitmap_print_sb(struct bitmap *bitmap)
kunmap_atomic(sb, KM_USER0);
}
/*
* bitmap_new_disk_sb
* @bitmap
*
* This function is somewhat the reverse of bitmap_read_sb. bitmap_read_sb
* reads and verifies the on-disk bitmap superblock and populates bitmap_info.
* This function verifies 'bitmap_info' and populates the on-disk bitmap
* structure, which is to be written to disk.
*
* Returns: 0 on success, -Exxx on error
*/
static int bitmap_new_disk_sb(struct bitmap *bitmap)
{
bitmap_super_t *sb;
unsigned long chunksize, daemon_sleep, write_behind;
int err = -EINVAL;
bitmap->sb_page = alloc_page(GFP_KERNEL);
if (IS_ERR(bitmap->sb_page)) {
err = PTR_ERR(bitmap->sb_page);
bitmap->sb_page = NULL;
return err;
}
bitmap->sb_page->index = 0;
sb = kmap_atomic(bitmap->sb_page, KM_USER0);
sb->magic = cpu_to_le32(BITMAP_MAGIC);
sb->version = cpu_to_le32(BITMAP_MAJOR_HI);
chunksize = bitmap->mddev->bitmap_info.chunksize;
BUG_ON(!chunksize);
if (!is_power_of_2(chunksize)) {
kunmap_atomic(sb, KM_USER0);
printk(KERN_ERR "bitmap chunksize not a power of 2\n");
return -EINVAL;
}
sb->chunksize = cpu_to_le32(chunksize);
daemon_sleep = bitmap->mddev->bitmap_info.daemon_sleep;
if (!daemon_sleep ||
(daemon_sleep < 1) || (daemon_sleep > MAX_SCHEDULE_TIMEOUT)) {
printk(KERN_INFO "Choosing daemon_sleep default (5 sec)\n");
daemon_sleep = 5 * HZ;
}
sb->daemon_sleep = cpu_to_le32(daemon_sleep);
bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
/*
* FIXME: write_behind for RAID1. If not specified, what
* is a good choice? We choose COUNTER_MAX / 2 arbitrarily.
*/
write_behind = bitmap->mddev->bitmap_info.max_write_behind;
if (write_behind > COUNTER_MAX)
write_behind = COUNTER_MAX / 2;
sb->write_behind = cpu_to_le32(write_behind);
bitmap->mddev->bitmap_info.max_write_behind = write_behind;
/* keep the array size field of the bitmap superblock up to date */
sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
memcpy(sb->uuid, bitmap->mddev->uuid, 16);
bitmap->flags |= BITMAP_STALE;
sb->state |= cpu_to_le32(BITMAP_STALE);
bitmap->events_cleared = bitmap->mddev->events;
sb->events_cleared = cpu_to_le64(bitmap->mddev->events);
bitmap->flags |= BITMAP_HOSTENDIAN;
sb->version = cpu_to_le32(BITMAP_MAJOR_HOSTENDIAN);
kunmap_atomic(sb, KM_USER0);
return 0;
}
/* read the superblock from the bitmap file and initialize some bitmap fields */
static int bitmap_read_sb(struct bitmap *bitmap)
{
@ -1076,8 +1152,8 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
}
printk(KERN_INFO "%s: bitmap initialized from disk: "
"read %lu/%lu pages, set %lu bits\n",
bmname(bitmap), bitmap->file_pages, num_pages, bit_cnt);
"read %lu/%lu pages, set %lu of %lu bits\n",
bmname(bitmap), bitmap->file_pages, num_pages, bit_cnt, chunks);
return 0;
@ -1728,9 +1804,16 @@ int bitmap_create(mddev_t *mddev)
vfs_fsync(file, 1);
}
/* read superblock from bitmap file (this sets mddev->bitmap_info.chunksize) */
if (!mddev->bitmap_info.external)
err = bitmap_read_sb(bitmap);
else {
if (!mddev->bitmap_info.external) {
/*
* If 'MD_ARRAY_FIRST_USE' is set, then device-mapper is
* instructing us to create a new on-disk bitmap instance.
*/
if (test_and_clear_bit(MD_ARRAY_FIRST_USE, &mddev->flags))
err = bitmap_new_disk_sb(bitmap);
else
err = bitmap_read_sb(bitmap);
} else {
err = 0;
if (mddev->bitmap_info.chunksize == 0 ||
mddev->bitmap_info.daemon_sleep == 0)

1
drivers/md/md.h
View File

@ -124,6 +124,7 @@ struct mddev_s
#define MD_CHANGE_DEVS 0 /* Some device status has changed */
#define MD_CHANGE_CLEAN 1 /* transition to or from 'clean' */
#define MD_CHANGE_PENDING 2 /* switch from 'clean' to 'active' in progress */
#define MD_ARRAY_FIRST_USE 3 /* First use of array, needs initialization */
int suspended;
atomic_t active_io;