From 9c81075f436f867f580c2edf2350c0898cffc9d0 Mon Sep 17 00:00:00 2001 From: Jonathan Brassow Date: Wed, 8 Jun 2011 17:59:30 -0500 Subject: [PATCH] MD: support initial bitmap creation in-kernel 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 Signed-off-by: NeilBrown --- drivers/md/bitmap.c | 93 ++++++++++++++++++++++++++++++++++++++++++--- drivers/md/md.h | 1 + 2 files changed, 89 insertions(+), 5 deletions(-) diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c index 70bd738b8b99..f0769b34d656 100644 --- a/drivers/md/bitmap.c +++ b/drivers/md/bitmap.c @@ -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) diff --git a/drivers/md/md.h b/drivers/md/md.h index 5e35535ab7c3..1c26c7a08ae6 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -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; -- 2.39.5