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 <neilb@suse.de>
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 29a3c86..9376526 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -29,6 +29,7 @@
#include "md.h"
#include "bitmap.h"
+#include <linux/dm-dirty-log.h>
/* debug macros */
#define DEBUG 0
@@ -694,6 +695,8 @@
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 @@
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 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;
+ if (!bitmap->filemap) {
+ struct dm_dirty_log *log = bitmap->mddev->bitmap_info.log;
+ if (log)
+ log->type->mark_region(log, chunk);
+ } else {
- page = filemap_get_page(bitmap, chunk);
- if (!page)
- return;
- bit = file_page_offset(bitmap, chunk);
+ 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);
-
+ /* 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 @@
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 @@
else
md_super_wait(bitmap->mddev);
}
+out:
if (bitmap->flags & BITMAP_WRITE_ERROR)
bitmap_file_kick(bitmap);
}
@@ -925,11 +951,11 @@
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 @@
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 @@
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 @@
-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 @@
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 @@
(*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 @@
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 @@
|| 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 3797dea..a7a1113 100644
--- a/drivers/md/bitmap.h
+++ b/drivers/md/bitmap.h
@@ -222,6 +222,10 @@
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 @@
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 0a85078..cccbadb 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -317,6 +317,11 @@
* 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? */
