Merge commit 'linus/master' into bkl/core

Merge reason: The staging tree has introduced the easycap
driver lately. We need the latest updates to pushdown the
bkl in its ioctl helper.

1 files changed, 43 insertions, 37 deletions

diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
index 735f019..001eb0e 100644
--- a/fs/ext3/inode.c
+++ b/fs/ext3/inode.c
@@ -1149,9 +1149,25 @@ static int walk_page_buffers(	handle_t *handle,
 static int do_journal_get_write_access(handle_t *handle,
 					struct buffer_head *bh)
 {
+	int dirty = buffer_dirty(bh);
+	int ret;
+
 	if (!buffer_mapped(bh) || buffer_freed(bh))
 		return 0;
-	return ext3_journal_get_write_access(handle, bh);
+	/*
+	 * __block_prepare_write() could have dirtied some buffers. Clean
+	 * the dirty bit as jbd2_journal_get_write_access() could complain
+	 * otherwise about fs integrity issues. Setting of the dirty bit
+	 * by __block_prepare_write() isn't a real problem here as we clear
+	 * the bit before releasing a page lock and thus writeback cannot
+	 * ever write the buffer.
+	 */
+	if (dirty)
+		clear_buffer_dirty(bh);
+	ret = ext3_journal_get_write_access(handle, bh);
+	if (!ret && dirty)
+		ret = ext3_journal_dirty_metadata(handle, bh);
+	return ret;
 }
 
 /*
@@ -1625,10 +1641,7 @@ static int ext3_writeback_writepage(struct page *page,
 		goto out_fail;
 	}
 
-	if (test_opt(inode->i_sb, NOBH) && ext3_should_writeback_data(inode))
-		ret = nobh_writepage(page, ext3_get_block, wbc);
-	else
-		ret = block_write_full_page(page, ext3_get_block, wbc);
+	ret = block_write_full_page(page, ext3_get_block, wbc);
 
 	err = ext3_journal_stop(handle);
 	if (!ret)
@@ -1922,17 +1935,6 @@ static int ext3_block_truncate_page(handle_t *handle, struct page *page,
 	length = blocksize - (offset & (blocksize - 1));
 	iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
 
-	/*
-	 * For "nobh" option,  we can only work if we don't need to
-	 * read-in the page - otherwise we create buffers to do the IO.
-	 */
-	if (!page_has_buffers(page) && test_opt(inode->i_sb, NOBH) &&
-	     ext3_should_writeback_data(inode) && PageUptodate(page)) {
-		zero_user(page, offset, length);
-		set_page_dirty(page);
-		goto unlock;
-	}
-
 	if (!page_has_buffers(page))
 		create_empty_buffers(page, blocksize, 0);
 
@@ -2284,27 +2286,6 @@ static void ext3_free_branches(handle_t *handle, struct inode *inode,
 					   depth);
 
 			/*
-			 * We've probably journalled the indirect block several
-			 * times during the truncate.  But it's no longer
-			 * needed and we now drop it from the transaction via
-			 * journal_revoke().
-			 *
-			 * That's easy if it's exclusively part of this
-			 * transaction.  But if it's part of the committing
-			 * transaction then journal_forget() will simply
-			 * brelse() it.  That means that if the underlying
-			 * block is reallocated in ext3_get_block(),
-			 * unmap_underlying_metadata() will find this block
-			 * and will try to get rid of it.  damn, damn.
-			 *
-			 * If this block has already been committed to the
-			 * journal, a revoke record will be written.  And
-			 * revoke records must be emitted *before* clearing
-			 * this block's bit in the bitmaps.
-			 */
-			ext3_forget(handle, 1, inode, bh, bh->b_blocknr);
-
-			/*
 			 * Everything below this this pointer has been
 			 * released.  Now let this top-of-subtree go.
 			 *
@@ -2327,6 +2308,31 @@ static void ext3_free_branches(handle_t *handle, struct inode *inode,
 				truncate_restart_transaction(handle, inode);
 			}
 
+			/*
+			 * We've probably journalled the indirect block several
+			 * times during the truncate.  But it's no longer
+			 * needed and we now drop it from the transaction via
+			 * journal_revoke().
+			 *
+			 * That's easy if it's exclusively part of this
+			 * transaction.  But if it's part of the committing
+			 * transaction then journal_forget() will simply
+			 * brelse() it.  That means that if the underlying
+			 * block is reallocated in ext3_get_block(),
+			 * unmap_underlying_metadata() will find this block
+			 * and will try to get rid of it.  damn, damn. Thus
+			 * we don't allow a block to be reallocated until
+			 * a transaction freeing it has fully committed.
+			 *
+			 * We also have to make sure journal replay after a
+			 * crash does not overwrite non-journaled data blocks
+			 * with old metadata when the block got reallocated for
+			 * data.  Thus we have to store a revoke record for a
+			 * block in the same transaction in which we free the
+			 * block.
+			 */
+			ext3_forget(handle, 1, inode, bh, bh->b_blocknr);
+
 			ext3_free_blocks(handle, inode, nr, 1);
 
 			if (parent_bh) {