From e384e58549a2e9a83071ad80280c1a9053cfd84c Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 1 Jun 2010 19:37:34 +1000 Subject: [PATCH] md/bitmap: prepare for storing write-intent-bitmap via dm-dirty-log. This allows md/raid5 to fully work as a dm target. Normally md uses a 'filemap' which contains a list of pages of bits each of which may be written separately. dm-log uses and all-or-nothing approach to writing the log, so when using a dm-log, ->filemap is NULL and the flags normally stored in filemap_attr are stored in ->logattrs instead. Signed-off-by: NeilBrown --- drivers/md/bitmap.c | 128 ++++++++++++++++++++++++++++++-------------- drivers/md/bitmap.h | 5 ++ drivers/md/md.h | 5 ++ 3 files changed, 99 insertions(+), 39 deletions(-) diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c index 29a3c864e6b0..93765261c363 100644 --- a/drivers/md/bitmap.c +++ b/drivers/md/bitmap.c @@ -29,6 +29,7 @@ #include "md.h" #include "bitmap.h" +#include /* debug macros */ #define DEBUG 0 @@ -694,6 +695,8 @@ static inline unsigned long file_page_offset(struct bitmap *bitmap, unsigned lon static inline struct page *filemap_get_page(struct bitmap *bitmap, unsigned long chunk) { + if (bitmap->filemap == NULL) + return NULL; if (file_page_index(bitmap, chunk) >= bitmap->file_pages) return NULL; return bitmap->filemap[file_page_index(bitmap, chunk) @@ -793,19 +796,28 @@ enum bitmap_page_attr { static inline void set_page_attr(struct bitmap *bitmap, struct page *page, enum bitmap_page_attr attr) { - __set_bit((page->index<<2) + attr, bitmap->filemap_attr); + if (page) + __set_bit((page->index<<2) + attr, bitmap->filemap_attr); + else + __set_bit(attr, &bitmap->logattrs); } static inline void clear_page_attr(struct bitmap *bitmap, struct page *page, enum bitmap_page_attr attr) { - __clear_bit((page->index<<2) + attr, bitmap->filemap_attr); + if (page) + __clear_bit((page->index<<2) + attr, bitmap->filemap_attr); + else + __clear_bit(attr, &bitmap->logattrs); } static inline unsigned long test_page_attr(struct bitmap *bitmap, struct page *page, enum bitmap_page_attr attr) { - return test_bit((page->index<<2) + attr, bitmap->filemap_attr); + if (page) + return test_bit((page->index<<2) + attr, bitmap->filemap_attr); + else + return test_bit(attr, &bitmap->logattrs); } /* @@ -818,27 +830,30 @@ static inline unsigned long test_page_attr(struct bitmap *bitmap, struct page *p static void bitmap_file_set_bit(struct bitmap *bitmap, sector_t block) { unsigned long bit; - struct page *page; + struct page *page = NULL; void *kaddr; unsigned long chunk = block >> CHUNK_BLOCK_SHIFT(bitmap); - if (!bitmap->filemap) - return; - - page = filemap_get_page(bitmap, chunk); - if (!page) - return; - bit = file_page_offset(bitmap, chunk); + if (!bitmap->filemap) { + struct dm_dirty_log *log = bitmap->mddev->bitmap_info.log; + if (log) + log->type->mark_region(log, chunk); + } else { - /* set the bit */ - kaddr = kmap_atomic(page, KM_USER0); - if (bitmap->flags & BITMAP_HOSTENDIAN) - set_bit(bit, kaddr); - else - ext2_set_bit(bit, kaddr); - kunmap_atomic(kaddr, KM_USER0); - PRINTK("set file bit %lu page %lu\n", bit, page->index); + page = filemap_get_page(bitmap, chunk); + if (!page) + return; + bit = file_page_offset(bitmap, chunk); + /* set the bit */ + kaddr = kmap_atomic(page, KM_USER0); + if (bitmap->flags & BITMAP_HOSTENDIAN) + set_bit(bit, kaddr); + else + ext2_set_bit(bit, kaddr); + kunmap_atomic(kaddr, KM_USER0); + PRINTK("set file bit %lu page %lu\n", bit, page->index); + } /* record page number so it gets flushed to disk when unplug occurs */ set_page_attr(bitmap, page, BITMAP_PAGE_DIRTY); } @@ -855,6 +870,16 @@ void bitmap_unplug(struct bitmap *bitmap) if (!bitmap) return; + if (!bitmap->filemap) { + /* Must be using a dirty_log */ + struct dm_dirty_log *log = bitmap->mddev->bitmap_info.log; + dirty = test_and_clear_bit(BITMAP_PAGE_DIRTY, &bitmap->logattrs); + need_write = test_and_clear_bit(BITMAP_PAGE_NEEDWRITE, &bitmap->logattrs); + if (dirty || need_write) + if (log->type->flush(log)) + bitmap->flags |= BITMAP_WRITE_ERROR; + goto out; + } /* look at each page to see if there are any set bits that need to be * flushed out to disk */ @@ -883,6 +908,7 @@ void bitmap_unplug(struct bitmap *bitmap) else md_super_wait(bitmap->mddev); } +out: if (bitmap->flags & BITMAP_WRITE_ERROR) bitmap_file_kick(bitmap); } @@ -925,11 +951,11 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start) printk(KERN_INFO "%s: bitmap file is out of date, doing full " "recovery\n", bmname(bitmap)); - bytes = (chunks + 7) / 8; + bytes = DIV_ROUND_UP(bitmap->chunks, 8); if (!bitmap->mddev->bitmap_info.external) bytes += sizeof(bitmap_super_t); - num_pages = (bytes + PAGE_SIZE - 1) / PAGE_SIZE; + num_pages = DIV_ROUND_UP(bytes, PAGE_SIZE); if (file && i_size_read(file->f_mapping->host) < bytes) { printk(KERN_INFO "%s: bitmap file too short %lu < %lu\n", @@ -1090,6 +1116,7 @@ void bitmap_daemon_work(mddev_t *mddev) struct page *page = NULL, *lastpage = NULL; int blocks; void *paddr; + struct dm_dirty_log *log = mddev->bitmap_info.log; /* Use a mutex to guard daemon_work against * bitmap_destroy. @@ -1114,11 +1141,12 @@ void bitmap_daemon_work(mddev_t *mddev) spin_lock_irqsave(&bitmap->lock, flags); for (j = 0; j < bitmap->chunks; j++) { bitmap_counter_t *bmc; - if (!bitmap->filemap) - /* error or shutdown */ - break; - - page = filemap_get_page(bitmap, j); + if (!bitmap->filemap) { + if (!log) + /* error or shutdown */ + break; + } else + page = filemap_get_page(bitmap, j); if (page != lastpage) { /* skip this page unless it's marked as needing cleaning */ @@ -1187,14 +1215,17 @@ void bitmap_daemon_work(mddev_t *mddev) -1); /* clear the bit */ - paddr = kmap_atomic(page, KM_USER0); - if (bitmap->flags & BITMAP_HOSTENDIAN) - clear_bit(file_page_offset(bitmap, j), - paddr); - else - ext2_clear_bit(file_page_offset(bitmap, j), - paddr); - kunmap_atomic(paddr, KM_USER0); + if (page) { + paddr = kmap_atomic(page, KM_USER0); + if (bitmap->flags & BITMAP_HOSTENDIAN) + clear_bit(file_page_offset(bitmap, j), + paddr); + else + ext2_clear_bit(file_page_offset(bitmap, j), + paddr); + kunmap_atomic(paddr, KM_USER0); + } else + log->type->clear_region(log, j); } } else j |= PAGE_COUNTER_MASK; @@ -1202,12 +1233,16 @@ void bitmap_daemon_work(mddev_t *mddev) spin_unlock_irqrestore(&bitmap->lock, flags); /* now sync the final page */ - if (lastpage != NULL) { + if (lastpage != NULL || log != NULL) { spin_lock_irqsave(&bitmap->lock, flags); if (test_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE)) { clear_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE); spin_unlock_irqrestore(&bitmap->lock, flags); - write_page(bitmap, lastpage, 0); + if (lastpage) + write_page(bitmap, lastpage, 0); + else + if (log->type->flush(log)) + bitmap->flags |= BITMAP_WRITE_ERROR; } else { set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE); spin_unlock_irqrestore(&bitmap->lock, flags); @@ -1372,7 +1407,9 @@ void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long secto (*bmc)--; if (*bmc <= 2) set_page_attr(bitmap, - filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap)), + filemap_get_page( + bitmap, + offset >> CHUNK_BLOCK_SHIFT(bitmap)), BITMAP_PAGE_CLEAN); spin_unlock_irqrestore(&bitmap->lock, flags); @@ -1649,10 +1686,13 @@ int bitmap_create(mddev_t *mddev) BUILD_BUG_ON(sizeof(bitmap_super_t) != 256); - if (!file && !mddev->bitmap_info.offset) /* bitmap disabled, nothing to do */ + if (!file + && !mddev->bitmap_info.offset + && !mddev->bitmap_info.log) /* bitmap disabled, nothing to do */ return 0; BUG_ON(file && mddev->bitmap_info.offset); + BUG_ON(mddev->bitmap_info.offset && mddev->bitmap_info.log); bitmap = kzalloc(sizeof(*bitmap), GFP_KERNEL); if (!bitmap) @@ -1730,7 +1770,17 @@ int bitmap_create(mddev_t *mddev) || bitmap->events_cleared == mddev->events) /* no need to keep dirty bits to optimise a re-add of a missing device */ start = mddev->recovery_cp; - err = bitmap_init_from_disk(bitmap, start); + if (mddev->bitmap_info.log) { + unsigned long i; + struct dm_dirty_log *log = mddev->bitmap_info.log; + for (i = 0; i < bitmap->chunks; i++) + if (!log->type->in_sync(log, i, 1)) + bitmap_set_memory_bits(bitmap, + (sector_t)i << CHUNK_BLOCK_SHIFT(bitmap), + 1); + err = 0; + } else + err = bitmap_init_from_disk(bitmap, start); if (err) goto error; diff --git a/drivers/md/bitmap.h b/drivers/md/bitmap.h index 3797dea4723a..a7a11134268d 100644 --- a/drivers/md/bitmap.h +++ b/drivers/md/bitmap.h @@ -222,6 +222,10 @@ struct bitmap { unsigned long file_pages; /* number of pages in the file */ int last_page_size; /* bytes in the last page */ + unsigned long logattrs; /* used when filemap_attr doesn't exist + * because we are working with a dirty_log + */ + unsigned long flags; int allclean; @@ -243,6 +247,7 @@ struct bitmap { wait_queue_head_t behind_wait; struct sysfs_dirent *sysfs_can_clear; + }; /* the bitmap API */ diff --git a/drivers/md/md.h b/drivers/md/md.h index 0a850780b5d1..cccbadb31bae 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -317,6 +317,11 @@ struct mddev_s * hot-adding a bitmap. It should * eventually be settable by sysfs. */ + /* When md is serving under dm, it might use a + * dirty_log to store the bits. + */ + struct dm_dirty_log *log; + struct mutex mutex; unsigned long chunksize; unsigned long daemon_sleep; /* how many jiffies between updates? */ -- 2.20.1