[md PATCH 34/34] MD bitmap: Revert DM dirty log hooks

[NeilBrown <neilb@suse.de>]

From: Jonathan Brassow <jbrassow@redhat.com>

Revert most of commit e384e58549a2e9a83071ad80280c1a9053cfd84c
  md/bitmap: prepare for storing write-intent-bitmap via dm-dirty-log.

MD should not need to use DM's dirty log - we decided to use md's
bitmaps instead.

Keeping the DIV_ROUND_UP clean-ups that were part of commit
e384e58549a2e9a83071ad80280c1a9053cfd84c, however.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
---

 drivers/md/bitmap.c |  133 ++++++++++++++++-----------------------------------
 drivers/md/bitmap.h |    5 --
 drivers/md/md.h     |    5 --
 3 files changed, 43 insertions(+), 100 deletions(-)

diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 39ff0ef..0dc6546 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -29,7 +29,6 @@
 #include "md.h"
 #include "bitmap.h"
 
-#include <linux/dm-dirty-log.h>
 /* debug macros */
 
 #define DEBUG 0
@@ -775,10 +774,8 @@ static inline unsigned long file_page_offset(struct bitmap *bitmap, unsigned lon
  * 0 or page 1
  */
 static inline struct page *filemap_get_page(struct bitmap *bitmap,
-					unsigned long chunk)
+					    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)
@@ -878,28 +875,19 @@ enum bitmap_page_attr {
 static inline void set_page_attr(struct bitmap *bitmap, struct page *page,
 				enum bitmap_page_attr attr)
 {
-	if (page)
-		__set_bit((page->index<<2) + attr, bitmap->filemap_attr);
-	else
-		__set_bit(attr, &bitmap->logattrs);
+	__set_bit((page->index<<2) + attr, bitmap->filemap_attr);
 }
 
 static inline void clear_page_attr(struct bitmap *bitmap, struct page *page,
 				enum bitmap_page_attr attr)
 {
-	if (page)
-		__clear_bit((page->index<<2) + attr, bitmap->filemap_attr);
-	else
-		__clear_bit(attr, &bitmap->logattrs);
+	__clear_bit((page->index<<2) + attr, bitmap->filemap_attr);
 }
 
 static inline unsigned long test_page_attr(struct bitmap *bitmap, struct page *page,
 					   enum bitmap_page_attr attr)
 {
-	if (page)
-		return test_bit((page->index<<2) + attr, bitmap->filemap_attr);
-	else
-		return test_bit(attr, &bitmap->logattrs);
+	return test_bit((page->index<<2) + attr, bitmap->filemap_attr);
 }
 
 /*
@@ -912,30 +900,26 @@ 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 = NULL;
+	struct page *page;
 	void *kaddr;
 	unsigned long chunk = block >> CHUNK_BLOCK_SHIFT(bitmap);
 
-	if (!bitmap->filemap) {
-		struct dm_dirty_log *log = bitmap->mddev->bitmap_info.log;
-		if (log)
-			log->type->mark_region(log, chunk);
-	} else {
+	if (!bitmap->filemap)
+		return;
 
-		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
-			__set_bit_le(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
+		__set_bit_le(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);
 }
@@ -952,16 +936,6 @@ 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 */
@@ -990,7 +964,6 @@ void bitmap_unplug(struct bitmap *bitmap)
 		else
 			md_super_wait(bitmap->mddev);
 	}
-out:
 	if (bitmap->flags & BITMAP_WRITE_ERROR)
 		bitmap_file_kick(bitmap);
 }
@@ -1199,7 +1172,6 @@ void bitmap_daemon_work(mddev_t *mddev)
 	struct page *page = NULL, *lastpage = NULL;
 	sector_t blocks;
 	void *paddr;
-	struct dm_dirty_log *log = mddev->bitmap_info.log;
 
 	/* Use a mutex to guard daemon_work against
 	 * bitmap_destroy.
@@ -1224,12 +1196,11 @@ 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) {
-			if (!log)
-				/* error or shutdown */
-				break;
-		} else
-			page = filemap_get_page(bitmap, j);
+		if (!bitmap->filemap)
+			/* error or shutdown */
+			break;
+
+		page = filemap_get_page(bitmap, j);
 
 		if (page != lastpage) {
 			/* skip this page unless it's marked as needing cleaning */
@@ -1298,19 +1269,16 @@ void bitmap_daemon_work(mddev_t *mddev)
 						  -1);
 
 				/* clear the bit */
-				if (page) {
-					paddr = kmap_atomic(page, KM_USER0);
-					if (bitmap->flags & BITMAP_HOSTENDIAN)
-						clear_bit(file_page_offset(bitmap, j),
-							  paddr);
-					else
-						__clear_bit_le(
+				paddr = kmap_atomic(page, KM_USER0);
+				if (bitmap->flags & BITMAP_HOSTENDIAN)
+					clear_bit(file_page_offset(bitmap, j),
+						  paddr);
+				else
+					__clear_bit_le(
 							file_page_offset(bitmap,
 									 j),
 							paddr);
-					kunmap_atomic(paddr, KM_USER0);
-				} else
-					log->type->clear_region(log, j);
+				kunmap_atomic(paddr, KM_USER0);
 			}
 		} else
 			j |= PAGE_COUNTER_MASK;
@@ -1318,16 +1286,12 @@ void bitmap_daemon_work(mddev_t *mddev)
 	spin_unlock_irqrestore(&bitmap->lock, flags);
 
 	/* now sync the final page */
-	if (lastpage != NULL || log != NULL) {
+	if (lastpage != 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);
-			if (lastpage)
-				write_page(bitmap, lastpage, 0);
-			else
-				if (log->type->flush(log))
-					bitmap->flags |= BITMAP_WRITE_ERROR;
+			write_page(bitmap, lastpage, 0);
 		} else {
 			set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
 			spin_unlock_irqrestore(&bitmap->lock, flags);
@@ -1769,12 +1733,10 @@ int bitmap_create(mddev_t *mddev)
 	BUILD_BUG_ON(sizeof(bitmap_super_t) != 256);
 
 	if (!file
-	    && !mddev->bitmap_info.offset
-	    && !mddev->bitmap_info.log) /* bitmap disabled, nothing to do */
+	    && !mddev->bitmap_info.offset) /* 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)
@@ -1865,6 +1827,7 @@ int bitmap_create(mddev_t *mddev)
 int bitmap_load(mddev_t *mddev)
 {
 	int err = 0;
+	sector_t start = 0;
 	sector_t sector = 0;
 	struct bitmap *bitmap = mddev->bitmap;
 
@@ -1883,24 +1846,14 @@ int bitmap_load(mddev_t *mddev)
 	}
 	bitmap_close_sync(bitmap);
 
-	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);
-	} else {
-		sector_t start = 0;
-		if (mddev->degraded == 0
-		    || 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->degraded == 0
+	    || 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 (err)
 		goto out;
 
diff --git a/drivers/md/bitmap.h b/drivers/md/bitmap.h
index b2a127e..a28f2e5 100644
--- a/drivers/md/bitmap.h
+++ b/drivers/md/bitmap.h
@@ -212,10 +212,6 @@ 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;
@@ -237,7 +233,6 @@ 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 de5455d..7d906a9 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -307,11 +307,6 @@ 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? */