1 files changed, 83 insertions, 144 deletions

diff --git a/fs/buffer.c b/fs/buffer.c
index 6fa530256bf..5930e382959 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -156,7 +156,7 @@ void end_buffer_write_sync(struct buffer_head *bh, int uptodate)
 	if (uptodate) {
 		set_buffer_uptodate(bh);
 	} else {
-		if (!buffer_eopnotsupp(bh) && !quiet_error(bh)) {
+		if (!quiet_error(bh)) {
 			buffer_io_error(bh);
 			printk(KERN_WARNING "lost page write due to "
 					"I/O error on %s\n",
@@ -275,6 +275,7 @@ void invalidate_bdev(struct block_device *bdev)
 		return;
 
 	invalidate_bh_lrus();
+	lru_add_drain_all();	/* make sure all lru add caches are flushed */
 	invalidate_mapping_pages(mapping, 0, -1);
 }
 EXPORT_SYMBOL(invalidate_bdev);
@@ -560,26 +561,17 @@ repeat:
 	return err;
 }
 
-static void do_thaw_all(struct work_struct *work)
+static void do_thaw_one(struct super_block *sb, void *unused)
 {
-	struct super_block *sb;
 	char b[BDEVNAME_SIZE];
+	while (sb->s_bdev && !thaw_bdev(sb->s_bdev, sb))
+		printk(KERN_WARNING "Emergency Thaw on %s\n",
+		       bdevname(sb->s_bdev, b));
+}
 
-	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);
+static void do_thaw_all(struct work_struct *work)
+{
+	iterate_supers(do_thaw_one, NULL);
 	kfree(work);
 	printk(KERN_WARNING "Emergency Thaw complete\n");
 }
@@ -778,11 +770,12 @@ static int fsync_buffers_list(spinlock_t *lock, struct list_head *list)
 				spin_unlock(lock);
 				/*
 				 * Ensure any pending I/O completes so that
-				 * ll_rw_block() actually writes the current
-				 * contents - it is a noop if I/O is still in
-				 * flight on potentially older contents.
+				 * write_dirty_buffer() actually writes the
+				 * current contents - it is a noop if I/O is
+				 * still in flight on potentially older
+				 * contents.
 				 */
-				ll_rw_block(SWRITE_SYNC_PLUG, 1, &bh);
+				write_dirty_buffer(bh, WRITE_SYNC_PLUG);
 
 				/*
 				 * Kick off IO for the previous mapping. Note
@@ -912,7 +905,6 @@ try_again:
 
 		bh->b_state = 0;
 		atomic_set(&bh->b_count, 0);
-		bh->b_private = NULL;
 		bh->b_size = size;
 
 		/* Link the buffer to its page */
@@ -1713,7 +1705,7 @@ static int __block_write_full_page(struct inode *inode, struct page *page,
 		 * and kswapd activity, but those code paths have their own
 		 * higher-level throttling.
 		 */
-		if (wbc->sync_mode != WB_SYNC_NONE || !wbc->nonblocking) {
+		if (wbc->sync_mode != WB_SYNC_NONE) {
 			lock_buffer(bh);
 		} else if (!trylock_buffer(bh)) {
 			redirty_page_for_writepage(wbc, page);
@@ -1841,9 +1833,12 @@ void page_zero_new_buffers(struct page *page, unsigned from, unsigned to)
 }
 EXPORT_SYMBOL(page_zero_new_buffers);
 
-static int __block_prepare_write(struct inode *inode, struct page *page,
-		unsigned from, unsigned to, get_block_t *get_block)
+int __block_write_begin(struct page *page, loff_t pos, unsigned len,
+		get_block_t *get_block)
 {
+	unsigned from = pos & (PAGE_CACHE_SIZE - 1);
+	unsigned to = from + len;
+	struct inode *inode = page->mapping->host;
 	unsigned block_start, block_end;
 	sector_t block;
 	int err = 0;
@@ -1916,10 +1911,13 @@ static int __block_prepare_write(struct inode *inode, struct page *page,
 		if (!buffer_uptodate(*wait_bh))
 			err = -EIO;
 	}
-	if (unlikely(err))
+	if (unlikely(err)) {
 		page_zero_new_buffers(page, from, to);
+		ClearPageUptodate(page);
+	}
 	return err;
 }
+EXPORT_SYMBOL(__block_write_begin);
 
 static int __block_commit_write(struct inode *inode, struct page *page,
 		unsigned from, unsigned to)
@@ -1960,58 +1958,27 @@ static int __block_commit_write(struct inode *inode, struct page *page,
  * block_write_begin takes care of the basic task of block allocation and
  * bringing partial write blocks uptodate first.
  *
- * If *pagep is not NULL, then block_write_begin uses the locked page
- * at *pagep rather than allocating its own. In this case, the page will
- * not be unlocked or deallocated on failure.
+ * The filesystem needs to handle block truncation upon failure.
  */
-int block_write_begin(struct file *file, struct address_space *mapping,
-			loff_t pos, unsigned len, unsigned flags,
-			struct page **pagep, void **fsdata,
-			get_block_t *get_block)
+int block_write_begin(struct address_space *mapping, loff_t pos, unsigned len,
+		unsigned flags, struct page **pagep, get_block_t *get_block)
 {
-	struct inode *inode = mapping->host;
-	int status = 0;
+	pgoff_t index = pos >> PAGE_CACHE_SHIFT;
 	struct page *page;
-	pgoff_t index;
-	unsigned start, end;
-	int ownpage = 0;
+	int status;
 
-	index = pos >> PAGE_CACHE_SHIFT;
-	start = pos & (PAGE_CACHE_SIZE - 1);
-	end = start + len;
-
-	page = *pagep;
-	if (page == NULL) {
-		ownpage = 1;
-		page = grab_cache_page_write_begin(mapping, index, flags);
-		if (!page) {
-			status = -ENOMEM;
-			goto out;
-		}
-		*pagep = page;
-	} else
-		BUG_ON(!PageLocked(page));
+	page = grab_cache_page_write_begin(mapping, index, flags);
+	if (!page)
+		return -ENOMEM;
 
-	status = __block_prepare_write(inode, page, start, end, get_block);
+	status = __block_write_begin(page, pos, len, get_block);
 	if (unlikely(status)) {
-		ClearPageUptodate(page);
-
-		if (ownpage) {
-			unlock_page(page);
-			page_cache_release(page);
-			*pagep = NULL;
-
-			/*
-			 * prepare_write() may have instantiated a few blocks
-			 * outside i_size.  Trim these off again. Don't need
-			 * i_size_read because we hold i_mutex.
-			 */
-			if (pos + len > inode->i_size)
-				vmtruncate(inode, inode->i_size);
-		}
+		unlock_page(page);
+		page_cache_release(page);
+		page = NULL;
 	}
 
-out:
+	*pagep = page;
 	return status;
 }
 EXPORT_SYMBOL(block_write_begin);
@@ -2344,7 +2311,7 @@ int cont_write_begin(struct file *file, struct address_space *mapping,
 
 	err = cont_expand_zero(file, mapping, pos, bytes);
 	if (err)
-		goto out;
+		return err;
 
 	zerofrom = *bytes & ~PAGE_CACHE_MASK;
 	if (pos+len > *bytes && zerofrom & (blocksize-1)) {
@@ -2352,25 +2319,10 @@ int cont_write_begin(struct file *file, struct address_space *mapping,
 		(*bytes)++;
 	}
 
-	*pagep = NULL;
-	err = block_write_begin(file, mapping, pos, len,
-				flags, pagep, fsdata, get_block);
-out:
-	return err;
+	return block_write_begin(mapping, pos, len, flags, pagep, get_block);
 }
 EXPORT_SYMBOL(cont_write_begin);
 
-int block_prepare_write(struct page *page, unsigned from, unsigned to,
-			get_block_t *get_block)
-{
-	struct inode *inode = page->mapping->host;
-	int err = __block_prepare_write(inode, page, from, to, get_block);
-	if (err)
-		ClearPageUptodate(page);
-	return err;
-}
-EXPORT_SYMBOL(block_prepare_write);
-
 int block_commit_write(struct page *page, unsigned from, unsigned to)
 {
 	struct inode *inode = page->mapping->host;
@@ -2389,7 +2341,7 @@ EXPORT_SYMBOL(block_commit_write);
  *
  * We are not allowed to take the i_mutex here so we have to play games to
  * protect against truncate races as the page could now be beyond EOF.  Because
- * vmtruncate() writes the inode size before removing pages, once we have the
+ * truncate writes the inode size before removing pages, once we have the
  * page lock we can determine safely if the page is beyond EOF. If it is not
  * beyond EOF, then the page is guaranteed safe against truncation until we
  * unlock the page.
@@ -2419,7 +2371,7 @@ block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
 	else
 		end = PAGE_CACHE_SIZE;
 
-	ret = block_prepare_write(page, 0, end, get_block);
+	ret = __block_write_begin(page, 0, end, get_block);
 	if (!ret)
 		ret = block_commit_write(page, 0, end);
 
@@ -2474,8 +2426,9 @@ static void attach_nobh_buffers(struct page *page, struct buffer_head *head)
 /*
  * On entry, the page is fully not uptodate.
  * On exit the page is fully uptodate in the areas outside (from,to)
+ * The filesystem needs to handle block truncation upon failure.
  */
-int nobh_write_begin(struct file *file, struct address_space *mapping,
+int nobh_write_begin(struct address_space *mapping,
 			loff_t pos, unsigned len, unsigned flags,
 			struct page **pagep, void **fsdata,
 			get_block_t *get_block)
@@ -2505,11 +2458,10 @@ int nobh_write_begin(struct file *file, struct address_space *mapping,
 	*fsdata = NULL;
 
 	if (page_has_buffers(page)) {
-		unlock_page(page);
-		page_cache_release(page);
-		*pagep = NULL;
-		return block_write_begin(file, mapping, pos, len, flags, pagep,
-					fsdata, get_block);
+		ret = __block_write_begin(page, pos, len, get_block);
+		if (unlikely(ret))
+			goto out_release;
+		return ret;
 	}
 
 	if (PageMappedToDisk(page))
@@ -2613,9 +2565,6 @@ out_release:
 	page_cache_release(page);
 	*pagep = NULL;
 
-	if (pos + len > inode->i_size)
-		vmtruncate(inode, inode->i_size);
-
 	return ret;
 }
 EXPORT_SYMBOL(nobh_write_begin);
@@ -2893,7 +2842,7 @@ int block_write_full_page_endio(struct page *page, get_block_t *get_block,
 
 	/*
 	 * The page straddles i_size.  It must be zeroed out on each and every
-	 * writepage invokation because it may be mmapped.  "A file is mapped
+	 * writepage invocation because it may be mmapped.  "A file is mapped
 	 * in multiples of the page size.  For a file that is not a multiple of
 	 * the  page size, the remaining memory is zeroed when mapped, and
 	 * writes to that region are not written out to the file."
@@ -2933,7 +2882,6 @@ static void end_bio_bh_io_sync(struct bio *bio, int err)
 
 	if (err == -EOPNOTSUPP) {
 		set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
-		set_bit(BH_Eopnotsupp, &bh->b_state);
 	}
 
 	if (unlikely (test_bit(BIO_QUIET,&bio->bi_flags)))
@@ -2955,13 +2903,6 @@ int submit_bh(int rw, struct buffer_head * bh)
 	BUG_ON(buffer_unwritten(bh));
 
 	/*
-	 * 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
 	 */
 	if (test_set_buffer_req(bh) && (rw & WRITE))
@@ -2999,22 +2940,21 @@ EXPORT_SYMBOL(submit_bh);
 
 /**
  * ll_rw_block: low-level access to block devices (DEPRECATED)
- * @rw: whether to %READ or %WRITE or %SWRITE or maybe %READA (readahead)
+ * @rw: whether to %READ or %WRITE or maybe %READA (readahead)
  * @nr: number of &struct buffer_heads in the array
  * @bhs: array of pointers to &struct buffer_head
  *
  * ll_rw_block() takes an array of pointers to &struct buffer_heads, and
  * requests an I/O operation on them, either a %READ or a %WRITE.  The third
- * %SWRITE is like %WRITE only we make sure that the *current* data in buffers
- * are sent to disk. The fourth %READA option is described in the documentation
- * for generic_make_request() which ll_rw_block() calls.
+ * %READA option is described in the documentation for generic_make_request()
+ * which ll_rw_block() calls.
  *
  * This function drops any buffer that it cannot get a lock on (with the
- * BH_Lock state bit) unless SWRITE is required, any buffer that appears to be
- * clean when doing a write request, and any buffer that appears to be
- * up-to-date when doing read request.  Further it marks as clean buffers that
- * are processed for writing (the buffer cache won't assume that they are
- * actually clean until the buffer gets unlocked).
+ * BH_Lock state bit), any buffer that appears to be clean when doing a write
+ * request, and any buffer that appears to be up-to-date when doing read
+ * request.  Further it marks as clean buffers that are processed for
+ * writing (the buffer cache won't assume that they are actually clean
+ * until the buffer gets unlocked).
  *
  * ll_rw_block sets b_end_io to simple completion handler that marks
  * the buffer up-to-date (if approriate), unlocks the buffer and wakes
@@ -3030,20 +2970,13 @@ 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 || rw == SWRITE_SYNC || rw == SWRITE_SYNC_PLUG)
-			lock_buffer(bh);
-		else if (!trylock_buffer(bh))
+		if (!trylock_buffer(bh))
 			continue;
-
-		if (rw == WRITE || rw == SWRITE || rw == SWRITE_SYNC ||
-		    rw == SWRITE_SYNC_PLUG) {
+		if (rw == WRITE) {
 			if (test_clear_buffer_dirty(bh)) {
 				bh->b_end_io = end_buffer_write_sync;
 				get_bh(bh);
-				if (rw == SWRITE_SYNC)
-					submit_bh(WRITE_SYNC, bh);
-				else
-					submit_bh(WRITE, bh);
+				submit_bh(WRITE, bh);
 				continue;
 			}
 		} else {
@@ -3059,12 +2992,25 @@ void ll_rw_block(int rw, int nr, struct buffer_head *bhs[])
 }
 EXPORT_SYMBOL(ll_rw_block);
 
+void write_dirty_buffer(struct buffer_head *bh, int rw)
+{
+	lock_buffer(bh);
+	if (!test_clear_buffer_dirty(bh)) {
+		unlock_buffer(bh);
+		return;
+	}
+	bh->b_end_io = end_buffer_write_sync;
+	get_bh(bh);
+	submit_bh(rw, bh);
+}
+EXPORT_SYMBOL(write_dirty_buffer);
+
 /*
  * For a data-integrity writeout, we need to wait upon any in-progress I/O
  * and then start new I/O and then wait upon it.  The caller must have a ref on
  * the buffer_head.
  */
-int sync_dirty_buffer(struct buffer_head *bh)
+int __sync_dirty_buffer(struct buffer_head *bh, int rw)
 {
 	int ret = 0;
 
@@ -3073,12 +3019,8 @@ 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_SYNC, bh);
+		ret = submit_bh(rw, bh);
 		wait_on_buffer(bh);
-		if (buffer_eopnotsupp(bh)) {
-			clear_buffer_eopnotsupp(bh);
-			ret = -EOPNOTSUPP;
-		}
 		if (!ret && !buffer_uptodate(bh))
 			ret = -EIO;
 	} else {
@@ -3086,6 +3028,12 @@ int sync_dirty_buffer(struct buffer_head *bh)
 	}
 	return ret;
 }
+EXPORT_SYMBOL(__sync_dirty_buffer);
+
+int sync_dirty_buffer(struct buffer_head *bh)
+{
+	return __sync_dirty_buffer(bh, WRITE_SYNC);
+}
 EXPORT_SYMBOL(sync_dirty_buffer);
 
 /*
@@ -3265,7 +3213,7 @@ 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, gfp_flags);
+	struct buffer_head *ret = kmem_cache_zalloc(bh_cachep, gfp_flags);
 	if (ret) {
 		INIT_LIST_HEAD(&ret->b_assoc_buffers);
 		get_cpu_var(bh_accounting).nr++;
@@ -3352,15 +3300,6 @@ int bh_submit_read(struct buffer_head *bh)
 }
 EXPORT_SYMBOL(bh_submit_read);
 
-static void
-init_buffer_head(void *data)
-{
-	struct buffer_head *bh = data;
-
-	memset(bh, 0, sizeof(*bh));
-	INIT_LIST_HEAD(&bh->b_assoc_buffers);
-}
-
 void __init buffer_init(void)
 {
 	int nrpages;
@@ -3369,7 +3308,7 @@ void __init buffer_init(void)
 			sizeof(struct buffer_head), 0,
 				(SLAB_RECLAIM_ACCOUNT|SLAB_PANIC|
 				SLAB_MEM_SPREAD),
-				init_buffer_head);
+				NULL);
 
 	/*
 	 * Limit the bh occupancy to 10% of ZONE_NORMAL