X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Fbuffer.c;h=b3e5be7514f5ce366b2a87262489bc88e1835a59;hb=595947acaaef373445131471a78650003f5d8e7d;hp=98196327ddf0dddc2b3a911441bd4ff493026abf;hpb=5b41e74ad1b0bf7bc51765ae74e5dc564afc3e48;p=safe%2Fjmp%2Flinux-2.6

diff --git a/fs/buffer.c b/fs/buffer.c
index 9819632..b3e5be7 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -76,8 +76,7 @@ EXPORT_SYMBOL(__lock_buffer);
 
 void unlock_buffer(struct buffer_head *bh)
 {
-	smp_mb__before_clear_bit();
-	clear_buffer_locked(bh);
+	clear_bit_unlock(BH_Lock, &bh->b_state);
 	smp_mb__after_clear_bit();
 	wake_up_bit(&bh->b_state, BH_Lock);
 }
@@ -100,10 +99,18 @@ __clear_page_buffers(struct page *page)
 	page_cache_release(page);
 }
 
+
+static int quiet_error(struct buffer_head *bh)
+{
+	if (!test_bit(BH_Quiet, &bh->b_state) && printk_ratelimit())
+		return 0;
+	return 1;
+}
+
+
 static void buffer_io_error(struct buffer_head *bh)
 {
 	char b[BDEVNAME_SIZE];
-
 	printk(KERN_ERR "Buffer I/O error on device %s, logical block %Lu\n",
 			bdevname(bh->b_bdev, b),
 			(unsigned long long)bh->b_blocknr);
@@ -145,7 +152,7 @@ void end_buffer_write_sync(struct buffer_head *bh, int uptodate)
 	if (uptodate) {
 		set_buffer_uptodate(bh);
 	} else {
-		if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
+		if (!buffer_eopnotsupp(bh) && !quiet_error(bh)) {
 			buffer_io_error(bh);
 			printk(KERN_WARNING "lost page write due to "
 					"I/O error on %s\n",
@@ -159,95 +166,6 @@ void end_buffer_write_sync(struct buffer_head *bh, int uptodate)
 }
 
 /*
- * Write out and wait upon all the dirty data associated with a block
- * device via its mapping.  Does not take the superblock lock.
- */
-int sync_blockdev(struct block_device *bdev)
-{
-	int ret = 0;
-
-	if (bdev)
-		ret = filemap_write_and_wait(bdev->bd_inode->i_mapping);
-	return ret;
-}
-EXPORT_SYMBOL(sync_blockdev);
-
-/*
- * Write out and wait upon all dirty data associated with this
- * device.   Filesystem data as well as the underlying block
- * device.  Takes the superblock lock.
- */
-int fsync_bdev(struct block_device *bdev)
-{
-	struct super_block *sb = get_super(bdev);
-	if (sb) {
-		int res = fsync_super(sb);
-		drop_super(sb);
-		return res;
-	}
-	return sync_blockdev(bdev);
-}
-
-/**
- * freeze_bdev  --  lock a filesystem and force it into a consistent state
- * @bdev:	blockdevice to lock
- *
- * This takes the block device bd_mount_sem to make sure no new mounts
- * happen on bdev until thaw_bdev() is called.
- * If a superblock is found on this device, we take the s_umount semaphore
- * on it to make sure nobody unmounts until the snapshot creation is done.
- */
-struct super_block *freeze_bdev(struct block_device *bdev)
-{
-	struct super_block *sb;
-
-	down(&bdev->bd_mount_sem);
-	sb = get_super(bdev);
-	if (sb && !(sb->s_flags & MS_RDONLY)) {
-		sb->s_frozen = SB_FREEZE_WRITE;
-		smp_wmb();
-
-		__fsync_super(sb);
-
-		sb->s_frozen = SB_FREEZE_TRANS;
-		smp_wmb();
-
-		sync_blockdev(sb->s_bdev);
-
-		if (sb->s_op->write_super_lockfs)
-			sb->s_op->write_super_lockfs(sb);
-	}
-
-	sync_blockdev(bdev);
-	return sb;	/* thaw_bdev releases s->s_umount and bd_mount_sem */
-}
-EXPORT_SYMBOL(freeze_bdev);
-
-/**
- * thaw_bdev  -- unlock filesystem
- * @bdev:	blockdevice to unlock
- * @sb:		associated superblock
- *
- * Unlocks the filesystem and marks it writeable again after freeze_bdev().
- */
-void thaw_bdev(struct block_device *bdev, struct super_block *sb)
-{
-	if (sb) {
-		BUG_ON(sb->s_bdev != bdev);
-
-		if (sb->s_op->unlockfs)
-			sb->s_op->unlockfs(sb);
-		sb->s_frozen = SB_UNFROZEN;
-		smp_wmb();
-		wake_up(&sb->s_wait_unfrozen);
-		drop_super(sb);
-	}
-
-	up(&bdev->bd_mount_sem);
-}
-EXPORT_SYMBOL(thaw_bdev);
-
-/*
  * Various filesystems appear to want __find_get_block to be non-blocking.
  * But it's the page lock which protects the buffers.  To get around this,
  * we get exclusion from try_to_free_buffers with the blockdev mapping's
@@ -281,13 +199,13 @@ __find_get_block_slow(struct block_device *bdev, sector_t block)
 	head = page_buffers(page);
 	bh = head;
 	do {
-		if (bh->b_blocknr == block) {
+		if (!buffer_mapped(bh))
+			all_mapped = 0;
+		else if (bh->b_blocknr == block) {
 			ret = bh;
 			get_bh(bh);
 			goto out_unlock;
 		}
-		if (!buffer_mapped(bh))
-			all_mapped = 0;
 		bh = bh->b_this_page;
 	} while (bh != head);
 
@@ -360,16 +278,19 @@ void invalidate_bdev(struct block_device *bdev)
  */
 static void free_more_memory(void)
 {
-	struct zone **zones;
-	pg_data_t *pgdat;
+	struct zone *zone;
+	int nid;
 
 	wakeup_pdflush(1024);
 	yield();
 
-	for_each_online_pgdat(pgdat) {
-		zones = pgdat->node_zonelists[gfp_zone(GFP_NOFS)].zones;
-		if (*zones)
-			try_to_free_pages(zones, 0, GFP_NOFS);
+	for_each_online_node(nid) {
+		(void)first_zones_zonelist(node_zonelist(nid, GFP_NOFS),
+						gfp_zone(GFP_NOFS), NULL,
+						&zone);
+		if (zone)
+			try_to_free_pages(node_zonelist(nid, GFP_NOFS), 0,
+						GFP_NOFS, NULL);
 	}
 }
 
@@ -392,7 +313,7 @@ static void end_buffer_async_read(struct buffer_head *bh, int uptodate)
 		set_buffer_uptodate(bh);
 	} else {
 		clear_buffer_uptodate(bh);
-		if (printk_ratelimit())
+		if (!quiet_error(bh))
 			buffer_io_error(bh);
 		SetPageError(page);
 	}
@@ -439,7 +360,7 @@ still_busy:
  * Completion handler for block_write_full_page() - pages which are unlocked
  * during I/O, and which have PageWriteback cleared upon I/O completion.
  */
-static void end_buffer_async_write(struct buffer_head *bh, int uptodate)
+void end_buffer_async_write(struct buffer_head *bh, int uptodate)
 {
 	char b[BDEVNAME_SIZE];
 	unsigned long flags;
@@ -453,7 +374,7 @@ static void end_buffer_async_write(struct buffer_head *bh, int uptodate)
 	if (uptodate) {
 		set_buffer_uptodate(bh);
 	} else {
-		if (printk_ratelimit()) {
+		if (!quiet_error(bh)) {
 			buffer_io_error(bh);
 			printk(KERN_WARNING "lost page write due to "
 					"I/O error on %s\n",
@@ -517,11 +438,17 @@ static void mark_buffer_async_read(struct buffer_head *bh)
 	set_buffer_async_read(bh);
 }
 
-void mark_buffer_async_write(struct buffer_head *bh)
+void mark_buffer_async_write_endio(struct buffer_head *bh,
+				   bh_end_io_t *handler)
 {
-	bh->b_end_io = end_buffer_async_write;
+	bh->b_end_io = handler;
 	set_buffer_async_write(bh);
 }
+
+void mark_buffer_async_write(struct buffer_head *bh)
+{
+	mark_buffer_async_write_endio(bh, end_buffer_async_write);
+}
 EXPORT_SYMBOL(mark_buffer_async_write);
 
 
@@ -577,7 +504,7 @@ EXPORT_SYMBOL(mark_buffer_async_write);
 /*
  * The buffer's backing address_space's private_lock must be held
  */
-static inline void __remove_assoc_queue(struct buffer_head *bh)
+static void __remove_assoc_queue(struct buffer_head *bh)
 {
 	list_del_init(&bh->b_assoc_buffers);
 	WARN_ON(!bh->b_assoc_map);
@@ -626,6 +553,46 @@ repeat:
 	return err;
 }
 
+void do_thaw_all(struct work_struct *work)
+{
+	struct super_block *sb;
+	char b[BDEVNAME_SIZE];
+
+	spin_lock(&sb_lock);
+restart:
+	list_for_each_entry(sb, &super_blocks, s_list) {
+		sb->s_count++;
+		spin_unlock(&sb_lock);
+		down_read(&sb->s_umount);
+		while (sb->s_bdev && !thaw_bdev(sb->s_bdev, sb))
+			printk(KERN_WARNING "Emergency Thaw on %s\n",
+			       bdevname(sb->s_bdev, b));
+		up_read(&sb->s_umount);
+		spin_lock(&sb_lock);
+		if (__put_super_and_need_restart(sb))
+			goto restart;
+	}
+	spin_unlock(&sb_lock);
+	kfree(work);
+	printk(KERN_WARNING "Emergency Thaw complete\n");
+}
+
+/**
+ * emergency_thaw_all -- forcibly thaw every frozen filesystem
+ *
+ * Used for emergency unfreeze of all filesystems via SysRq
+ */
+void emergency_thaw_all(void)
+{
+	struct work_struct *work;
+
+	work = kmalloc(sizeof(*work), GFP_ATOMIC);
+	if (work) {
+		INIT_WORK(work, do_thaw_all);
+		schedule_work(work);
+	}
+}
+
 /**
  * sync_mapping_buffers - write out & wait upon a mapping's "associated" buffers
  * @mapping: the mapping which wants those buffers written
@@ -694,32 +661,18 @@ EXPORT_SYMBOL(mark_buffer_dirty_inode);
  * If warn is true, then emit a warning if the page is not uptodate and has
  * not been truncated.
  */
-static int __set_page_dirty(struct page *page,
+static void __set_page_dirty(struct page *page,
 		struct address_space *mapping, int warn)
 {
-	if (unlikely(!mapping))
-		return !TestSetPageDirty(page);
-
-	if (TestSetPageDirty(page))
-		return 0;
-
-	write_lock_irq(&mapping->tree_lock);
+	spin_lock_irq(&mapping->tree_lock);
 	if (page->mapping) {	/* Race with truncate? */
 		WARN_ON_ONCE(warn && !PageUptodate(page));
-
-		if (mapping_cap_account_dirty(mapping)) {
-			__inc_zone_page_state(page, NR_FILE_DIRTY);
-			__inc_bdi_stat(mapping->backing_dev_info,
-					BDI_RECLAIMABLE);
-			task_io_account_write(PAGE_CACHE_SIZE);
-		}
+		account_page_dirtied(page, mapping);
 		radix_tree_tag_set(&mapping->page_tree,
 				page_index(page), PAGECACHE_TAG_DIRTY);
 	}
-	write_unlock_irq(&mapping->tree_lock);
+	spin_unlock_irq(&mapping->tree_lock);
 	__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
-
-	return 1;
 }
 
 /*
@@ -749,6 +702,7 @@ static int __set_page_dirty(struct page *page,
  */
 int __set_page_dirty_buffers(struct page *page)
 {
+	int newly_dirty;
 	struct address_space *mapping = page_mapping(page);
 
 	if (unlikely(!mapping))
@@ -764,9 +718,12 @@ int __set_page_dirty_buffers(struct page *page)
 			bh = bh->b_this_page;
 		} while (bh != head);
 	}
+	newly_dirty = !TestSetPageDirty(page);
 	spin_unlock(&mapping->private_lock);
 
-	return __set_page_dirty(page, mapping, 1);
+	if (newly_dirty)
+		__set_page_dirty(page, mapping, 1);
+	return newly_dirty;
 }
 EXPORT_SYMBOL(__set_page_dirty_buffers);
 
@@ -793,7 +750,7 @@ static int fsync_buffers_list(spinlock_t *lock, struct list_head *list)
 {
 	struct buffer_head *bh;
 	struct list_head tmp;
-	struct address_space *mapping;
+	struct address_space *mapping, *prev_mapping = NULL;
 	int err = 0, err2;
 
 	INIT_LIST_HEAD(&tmp);
@@ -818,7 +775,18 @@ static int fsync_buffers_list(spinlock_t *lock, struct list_head *list)
 				 * contents - it is a noop if I/O is still in
 				 * flight on potentially older contents.
 				 */
-				ll_rw_block(SWRITE, 1, &bh);
+				ll_rw_block(SWRITE_SYNC_PLUG, 1, &bh);
+
+				/*
+				 * Kick off IO for the previous mapping. Note
+				 * that we will not run the very last mapping,
+				 * wait_on_buffer() will do that for us
+				 * through sync_buffer().
+				 */
+				if (prev_mapping && prev_mapping != mapping)
+					blk_run_address_space(prev_mapping);
+				prev_mapping = mapping;
+
 				brelse(bh);
 				spin_lock(lock);
 			}
@@ -876,6 +844,7 @@ void invalidate_inode_buffers(struct inode *inode)
 		spin_unlock(&buffer_mapping->private_lock);
 	}
 }
+EXPORT_SYMBOL(invalidate_inode_buffers);
 
 /*
  * Remove any clean buffers from the inode's buffer list.  This is called
@@ -1098,7 +1067,7 @@ grow_buffers(struct block_device *bdev, sector_t block, int size)
 
 		printk(KERN_ERR "%s: requested out-of-range block %llu for "
 			"device %s\n",
-			__FUNCTION__, (unsigned long long)block,
+			__func__, (unsigned long long)block,
 			bdevname(bdev, b));
 		return -EIO;
 	}
@@ -1181,8 +1150,24 @@ __getblk_slow(struct block_device *bdev, sector_t block, int size)
 void mark_buffer_dirty(struct buffer_head *bh)
 {
 	WARN_ON_ONCE(!buffer_uptodate(bh));
-	if (!buffer_dirty(bh) && !test_set_buffer_dirty(bh))
-		__set_page_dirty(bh->b_page, page_mapping(bh->b_page), 0);
+
+	/*
+	 * Very *carefully* optimize the it-is-already-dirty case.
+	 *
+	 * Don't let the final "is it dirty" escape to before we
+	 * perhaps modified the buffer.
+	 */
+	if (buffer_dirty(bh)) {
+		smp_mb();
+		if (buffer_dirty(bh))
+			return;
+	}
+
+	if (!test_set_buffer_dirty(bh)) {
+		struct page *page = bh->b_page;
+		if (!TestSetPageDirty(page))
+			__set_page_dirty(page, page_mapping(page), 0);
+	}
 }
 
 /*
@@ -1198,8 +1183,7 @@ void __brelse(struct buffer_head * buf)
 		put_bh(buf);
 		return;
 	}
-	printk(KERN_ERR "VFS: brelse: Trying to free free buffer\n");
-	WARN_ON(1);
+	WARN(1, KERN_ERR "VFS: brelse: Trying to free free buffer\n");
 }
 
 /*
@@ -1448,7 +1432,7 @@ static void invalidate_bh_lru(void *arg)
 	
 void invalidate_bh_lrus(void)
 {
-	on_each_cpu(invalidate_bh_lru, NULL, 1, 1);
+	on_each_cpu(invalidate_bh_lru, NULL, 1);
 }
 EXPORT_SYMBOL_GPL(invalidate_bh_lrus);
 
@@ -1625,9 +1609,20 @@ EXPORT_SYMBOL(unmap_underlying_metadata);
  * locked buffer.   This only can happen if someone has written the buffer
  * directly, with submit_bh().  At the address_space level PageWriteback
  * prevents this contention from occurring.
+ *
+ * If block_write_full_page() is called with wbc->sync_mode ==
+ * WB_SYNC_ALL, the writes are posted using WRITE_SYNC_PLUG; this
+ * causes the writes to be flagged as synchronous writes, but the
+ * block device queue will NOT be unplugged, since usually many pages
+ * will be pushed to the out before the higher-level caller actually
+ * waits for the writes to be completed.  The various wait functions,
+ * such as wait_on_writeback_range() will ultimately call sync_page()
+ * which will ultimately call blk_run_backing_dev(), which will end up
+ * unplugging the device queue.
  */
 static int __block_write_full_page(struct inode *inode, struct page *page,
-			get_block_t *get_block, struct writeback_control *wbc)
+			get_block_t *get_block, struct writeback_control *wbc,
+			bh_end_io_t *handler)
 {
 	int err;
 	sector_t block;
@@ -1635,6 +1630,8 @@ static int __block_write_full_page(struct inode *inode, struct page *page,
 	struct buffer_head *bh, *head;
 	const unsigned blocksize = 1 << inode->i_blkbits;
 	int nr_underway = 0;
+	int write_op = (wbc->sync_mode == WB_SYNC_ALL ?
+			WRITE_SYNC_PLUG : WRITE);
 
 	BUG_ON(!PageLocked(page));
 
@@ -1675,11 +1672,13 @@ static int __block_write_full_page(struct inode *inode, struct page *page,
 			 */
 			clear_buffer_dirty(bh);
 			set_buffer_uptodate(bh);
-		} else if (!buffer_mapped(bh) && buffer_dirty(bh)) {
+		} else if ((!buffer_mapped(bh) || buffer_delay(bh)) &&
+			   buffer_dirty(bh)) {
 			WARN_ON(bh->b_size != blocksize);
 			err = get_block(inode, block, bh, 1);
 			if (err)
 				goto recover;
+			clear_buffer_delay(bh);
 			if (buffer_new(bh)) {
 				/* blockdev mappings never come here */
 				clear_buffer_new(bh);
@@ -1703,12 +1702,12 @@ static int __block_write_full_page(struct inode *inode, struct page *page,
 		 */
 		if (wbc->sync_mode != WB_SYNC_NONE || !wbc->nonblocking) {
 			lock_buffer(bh);
-		} else if (test_set_buffer_locked(bh)) {
+		} else if (!trylock_buffer(bh)) {
 			redirty_page_for_writepage(wbc, page);
 			continue;
 		}
 		if (test_clear_buffer_dirty(bh)) {
-			mark_buffer_async_write(bh);
+			mark_buffer_async_write_endio(bh, handler);
 		} else {
 			unlock_buffer(bh);
 		}
@@ -1724,7 +1723,7 @@ static int __block_write_full_page(struct inode *inode, struct page *page,
 	do {
 		struct buffer_head *next = bh->b_this_page;
 		if (buffer_async_write(bh)) {
-			submit_bh(WRITE, bh);
+			submit_bh(write_op, bh);
 			nr_underway++;
 		}
 		bh = next;
@@ -1758,9 +1757,10 @@ recover:
 	bh = head;
 	/* Recovery: lock and submit the mapped buffers */
 	do {
-		if (buffer_mapped(bh) && buffer_dirty(bh)) {
+		if (buffer_mapped(bh) && buffer_dirty(bh) &&
+		    !buffer_delay(bh)) {
 			lock_buffer(bh);
-			mark_buffer_async_write(bh);
+			mark_buffer_async_write_endio(bh, handler);
 		} else {
 			/*
 			 * The buffer may have been set dirty during
@@ -1777,7 +1777,7 @@ recover:
 		struct buffer_head *next = bh->b_this_page;
 		if (buffer_async_write(bh)) {
 			clear_buffer_dirty(bh);
-			submit_bh(WRITE, bh);
+			submit_bh(write_op, bh);
 			nr_underway++;
 		}
 		bh = next;
@@ -1970,7 +1970,7 @@ int block_write_begin(struct file *file, struct address_space *mapping,
 	page = *pagep;
 	if (page == NULL) {
 		ownpage = 1;
-		page = __grab_cache_page(mapping, index);
+		page = grab_cache_page_write_begin(mapping, index, flags);
 		if (!page) {
 			status = -ENOMEM;
 			goto out;
@@ -1996,7 +1996,6 @@ int block_write_begin(struct file *file, struct address_space *mapping,
 			if (pos + len > inode->i_size)
 				vmtruncate(inode, inode->i_size);
 		}
-		goto out;
 	}
 
 out:
@@ -2045,6 +2044,7 @@ int generic_write_end(struct file *file, struct address_space *mapping,
 			struct page *page, void *fsdata)
 {
 	struct inode *inode = mapping->host;
+	int i_size_changed = 0;
 
 	copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);
 
@@ -2057,17 +2057,72 @@ int generic_write_end(struct file *file, struct address_space *mapping,
 	 */
 	if (pos+copied > inode->i_size) {
 		i_size_write(inode, pos+copied);
-		mark_inode_dirty(inode);
+		i_size_changed = 1;
 	}
 
 	unlock_page(page);
 	page_cache_release(page);
 
+	/*
+	 * Don't mark the inode dirty under page lock. First, it unnecessarily
+	 * makes the holding time of page lock longer. Second, it forces lock
+	 * ordering of page lock and transaction start for journaling
+	 * filesystems.
+	 */
+	if (i_size_changed)
+		mark_inode_dirty(inode);
+
 	return copied;
 }
 EXPORT_SYMBOL(generic_write_end);
 
 /*
+ * block_is_partially_uptodate checks whether buffers within a page are
+ * uptodate or not.
+ *
+ * Returns true if all buffers which correspond to a file portion
+ * we want to read are uptodate.
+ */
+int block_is_partially_uptodate(struct page *page, read_descriptor_t *desc,
+					unsigned long from)
+{
+	struct inode *inode = page->mapping->host;
+	unsigned block_start, block_end, blocksize;
+	unsigned to;
+	struct buffer_head *bh, *head;
+	int ret = 1;
+
+	if (!page_has_buffers(page))
+		return 0;
+
+	blocksize = 1 << inode->i_blkbits;
+	to = min_t(unsigned, PAGE_CACHE_SIZE - from, desc->count);
+	to = from + to;
+	if (from < blocksize && to > PAGE_CACHE_SIZE - blocksize)
+		return 0;
+
+	head = page_buffers(page);
+	bh = head;
+	block_start = 0;
+	do {
+		block_end = block_start + blocksize;
+		if (block_end > from && block_start < to) {
+			if (!buffer_uptodate(bh)) {
+				ret = 0;
+				break;
+			}
+			if (block_end >= to)
+				break;
+		}
+		block_start = block_end;
+		bh = bh->b_this_page;
+	} while (bh != head);
+
+	return ret;
+}
+EXPORT_SYMBOL(block_is_partially_uptodate);
+
+/*
  * Generic "read page" function for block devices that have the normal
  * get_block functionality. This is most of the block device filesystems.
  * Reads the page asynchronously --- the unlock_buffer() and
@@ -2195,8 +2250,8 @@ out:
 	return err;
 }
 
-int cont_expand_zero(struct file *file, struct address_space *mapping,
-			loff_t pos, loff_t *bytes)
+static int cont_expand_zero(struct file *file, struct address_space *mapping,
+			    loff_t pos, loff_t *bytes)
 {
 	struct inode *inode = mapping->host;
 	unsigned blocksize = 1 << inode->i_blkbits;
@@ -2230,6 +2285,8 @@ int cont_expand_zero(struct file *file, struct address_space *mapping,
 			goto out;
 		BUG_ON(err != len);
 		err = 0;
+
+		balance_dirty_pages_ratelimited(mapping);
 	}
 
 	/* page covers the boundary, find the boundary offset */
@@ -2310,23 +2367,6 @@ int block_commit_write(struct page *page, unsigned from, unsigned to)
 	return 0;
 }
 
-int generic_commit_write(struct file *file, struct page *page,
-		unsigned from, unsigned to)
-{
-	struct inode *inode = page->mapping->host;
-	loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
-	__block_commit_write(inode,page,from,to);
-	/*
-	 * No need to use i_size_read() here, the i_size
-	 * cannot change under us because we hold i_mutex.
-	 */
-	if (pos > inode->i_size) {
-		i_size_write(inode, pos);
-		mark_inode_dirty(inode);
-	}
-	return 0;
-}
-
 /*
  * block_page_mkwrite() is not allowed to change the file size as it gets
  * called from a page fault handler when a page is first dirtied. Hence we must
@@ -2343,13 +2383,14 @@ int generic_commit_write(struct file *file, struct page *page,
  * unlock the page.
  */
 int
-block_page_mkwrite(struct vm_area_struct *vma, struct page *page,
+block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
 		   get_block_t get_block)
 {
+	struct page *page = vmf->page;
 	struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
 	unsigned long end;
 	loff_t size;
-	int ret = -EINVAL;
+	int ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
 
 	lock_page(page);
 	size = i_size_read(inode);
@@ -2369,6 +2410,13 @@ block_page_mkwrite(struct vm_area_struct *vma, struct page *page,
 	if (!ret)
 		ret = block_commit_write(page, 0, end);
 
+	if (unlikely(ret)) {
+		if (ret == -ENOMEM)
+			ret = VM_FAULT_OOM;
+		else /* -ENOSPC, -EIO, etc */
+			ret = VM_FAULT_SIGBUS;
+	}
+
 out_unlock:
 	unlock_page(page);
 	return ret;
@@ -2435,7 +2483,7 @@ int nobh_write_begin(struct file *file, struct address_space *mapping,
 	from = pos & (PAGE_CACHE_SIZE - 1);
 	to = from + len;
 
-	page = __grab_cache_page(mapping, index);
+	page = grab_cache_page_write_begin(mapping, index, flags);
 	if (!page)
 		return -ENOMEM;
 	*pagep = page;
@@ -2566,7 +2614,7 @@ int nobh_write_end(struct file *file, struct address_space *mapping,
 	struct buffer_head *bh;
 	BUG_ON(fsdata != NULL && page_has_buffers(page));
 
-	if (unlikely(copied < len) && !page_has_buffers(page))
+	if (unlikely(copied < len) && head)
 		attach_nobh_buffers(page, head);
 	if (page_has_buffers(page))
 		return generic_write_end(file, mapping, pos, len,
@@ -2638,7 +2686,8 @@ int nobh_writepage(struct page *page, get_block_t *get_block,
 out:
 	ret = mpage_writepage(page, get_block, wbc);
 	if (ret == -EAGAIN)
-		ret = __block_write_full_page(inode, page, get_block, wbc);
+		ret = __block_write_full_page(inode, page, get_block, wbc,
+					      end_buffer_async_write);
 	return ret;
 }
 EXPORT_SYMBOL(nobh_writepage);
@@ -2796,9 +2845,10 @@ out:
 
 /*
  * The generic ->writepage function for buffer-backed address_spaces
+ * this form passes in the end_io handler used to finish the IO.
  */
-int block_write_full_page(struct page *page, get_block_t *get_block,
-			struct writeback_control *wbc)
+int block_write_full_page_endio(struct page *page, get_block_t *get_block,
+			struct writeback_control *wbc, bh_end_io_t *handler)
 {
 	struct inode * const inode = page->mapping->host;
 	loff_t i_size = i_size_read(inode);
@@ -2807,7 +2857,8 @@ int block_write_full_page(struct page *page, get_block_t *get_block,
 
 	/* Is the page fully inside i_size? */
 	if (page->index < end_index)
-		return __block_write_full_page(inode, page, get_block, wbc);
+		return __block_write_full_page(inode, page, get_block, wbc,
+					       handler);
 
 	/* Is the page fully outside i_size? (truncate in progress) */
 	offset = i_size & (PAGE_CACHE_SIZE-1);
@@ -2830,9 +2881,20 @@ int block_write_full_page(struct page *page, get_block_t *get_block,
 	 * writes to that region are not written out to the file."
 	 */
 	zero_user_segment(page, offset, PAGE_CACHE_SIZE);
-	return __block_write_full_page(inode, page, get_block, wbc);
+	return __block_write_full_page(inode, page, get_block, wbc, handler);
+}
+
+/*
+ * The generic ->writepage function for buffer-backed address_spaces
+ */
+int block_write_full_page(struct page *page, get_block_t *get_block,
+			struct writeback_control *wbc)
+{
+	return block_write_full_page_endio(page, get_block, wbc,
+					   end_buffer_async_write);
 }
 
+
 sector_t generic_block_bmap(struct address_space *mapping, sector_t block,
 			    get_block_t *get_block)
 {
@@ -2854,6 +2916,9 @@ static void end_bio_bh_io_sync(struct bio *bio, int err)
 		set_bit(BH_Eopnotsupp, &bh->b_state);
 	}
 
+	if (unlikely (test_bit(BIO_QUIET,&bio->bi_flags)))
+		set_bit(BH_Quiet, &bh->b_state);
+
 	bh->b_end_io(bh, test_bit(BIO_UPTODATE, &bio->bi_flags));
 	bio_put(bio);
 }
@@ -2867,14 +2932,17 @@ int submit_bh(int rw, struct buffer_head * bh)
 	BUG_ON(!buffer_mapped(bh));
 	BUG_ON(!bh->b_end_io);
 
-	if (buffer_ordered(bh) && (rw == WRITE))
-		rw = WRITE_BARRIER;
+	/*
+	 * Mask in barrier bit for a write (could be either a WRITE or a
+	 * WRITE_SYNC
+	 */
+	if (buffer_ordered(bh) && (rw & WRITE))
+		rw |= WRITE_BARRIER;
 
 	/*
-	 * Only clear out a write error when rewriting, should this
-	 * include WRITE_SYNC as well?
+	 * Only clear out a write error when rewriting
 	 */
-	if (test_set_buffer_req(bh) && (rw == WRITE || rw == WRITE_BARRIER))
+	if (test_set_buffer_req(bh) && (rw & WRITE))
 		clear_buffer_write_io_error(bh);
 
 	/*
@@ -2939,16 +3007,20 @@ void ll_rw_block(int rw, int nr, struct buffer_head *bhs[])
 	for (i = 0; i < nr; i++) {
 		struct buffer_head *bh = bhs[i];
 
-		if (rw == SWRITE)
+		if (rw == SWRITE || rw == SWRITE_SYNC || rw == SWRITE_SYNC_PLUG)
 			lock_buffer(bh);
-		else if (test_set_buffer_locked(bh))
+		else if (!trylock_buffer(bh))
 			continue;
 
-		if (rw == WRITE || rw == SWRITE) {
+		if (rw == WRITE || rw == SWRITE || rw == SWRITE_SYNC ||
+		    rw == SWRITE_SYNC_PLUG) {
 			if (test_clear_buffer_dirty(bh)) {
 				bh->b_end_io = end_buffer_write_sync;
 				get_bh(bh);
-				submit_bh(WRITE, bh);
+				if (rw == SWRITE_SYNC)
+					submit_bh(WRITE_SYNC, bh);
+				else
+					submit_bh(WRITE, bh);
 				continue;
 			}
 		} else {
@@ -2977,7 +3049,7 @@ int sync_dirty_buffer(struct buffer_head *bh)
 	if (test_clear_buffer_dirty(bh)) {
 		get_bh(bh);
 		bh->b_end_io = end_buffer_write_sync;
-		ret = submit_bh(WRITE, bh);
+		ret = submit_bh(WRITE_SYNC, bh);
 		wait_on_buffer(bh);
 		if (buffer_eopnotsupp(bh)) {
 			clear_buffer_eopnotsupp(bh);
@@ -3112,7 +3184,7 @@ void block_sync_page(struct page *page)
  * Use of bdflush() is deprecated and will be removed in a future kernel.
  * The `pdflush' kernel threads fully replace bdflush daemons and this call.
  */
-asmlinkage long sys_bdflush(int func, long data)
+SYSCALL_DEFINE2(bdflush, int, func, long, data)
 {
 	static int msg_count;
 
@@ -3167,8 +3239,7 @@ static void recalc_bh_state(void)
 	
 struct buffer_head *alloc_buffer_head(gfp_t gfp_flags)
 {
-	struct buffer_head *ret = kmem_cache_alloc(bh_cachep,
-				set_migrateflags(gfp_flags, __GFP_RECLAIMABLE));
+	struct buffer_head *ret = kmem_cache_alloc(bh_cachep, gfp_flags);
 	if (ret) {
 		INIT_LIST_HEAD(&ret->b_assoc_buffers);
 		get_cpu_var(bh_accounting).nr++;
@@ -3256,7 +3327,7 @@ int bh_submit_read(struct buffer_head *bh)
 EXPORT_SYMBOL(bh_submit_read);
 
 static void
-init_buffer_head(struct kmem_cache *cachep, void *data)
+init_buffer_head(void *data)
 {
 	struct buffer_head *bh = data;
 
@@ -3292,13 +3363,13 @@ EXPORT_SYMBOL(block_read_full_page);
 EXPORT_SYMBOL(block_sync_page);
 EXPORT_SYMBOL(block_truncate_page);
 EXPORT_SYMBOL(block_write_full_page);
+EXPORT_SYMBOL(block_write_full_page_endio);
 EXPORT_SYMBOL(cont_write_begin);
 EXPORT_SYMBOL(end_buffer_read_sync);
 EXPORT_SYMBOL(end_buffer_write_sync);
+EXPORT_SYMBOL(end_buffer_async_write);
 EXPORT_SYMBOL(file_fsync);
-EXPORT_SYMBOL(fsync_bdev);
 EXPORT_SYMBOL(generic_block_bmap);
-EXPORT_SYMBOL(generic_commit_write);
 EXPORT_SYMBOL(generic_cont_expand_simple);
 EXPORT_SYMBOL(init_buffer);
 EXPORT_SYMBOL(invalidate_bdev);