linux-ext4 - [PATCH 2/4] ext4: prevent fsreentrance deadlock for inline

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Message-Id: <1417518054-21733-2-git-send-email-dmonakhov@openvz.org>
Date:	Tue,  2 Dec 2014 15:00:52 +0400
From:	Dmitry Monakhov <dmonakhov@...nvz.org>
To:	linux-ext4@...r.kernel.org
Cc:	tytso@....edu, Dmitry Monakhov <dmonakhov@...nvz.org>
Subject: [PATCH 2/4] ext4: prevent fsreentrance deadlock for inline_data

ext4_da_convert_inline_data_to_extent() invokes grab_cache_page_write_begin().
grab_cache_page_write_begin performs memory allocation, so fs-reentrance
should be prohibited because we are inside journal transaction.

Signed-off-by: Dmitry Monakhov <dmonakhov@...nvz.org>
---
 fs/ext4/inline.c |   11 ++++++-----
 1 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index 3ea6269..efdcede 100644
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -870,6 +870,12 @@ retry_journal:
 			goto out_journal;
 	}
 
+	/*
+	 * We cannot recurse into the filesystem as the transaction
+	 * is already started.
+	 */
+	flags |= AOP_FLAG_NOFS;
+
 	if (ret == -ENOSPC) {
 		ret = ext4_da_convert_inline_data_to_extent(mapping,
 							    inode,
@@ -882,11 +888,6 @@ retry_journal:
 		goto out;
 	}
 
-	/*
-	 * We cannot recurse into the filesystem as the transaction
-	 * is already started.
-	 */
-	flags |= AOP_FLAG_NOFS;
 
 	page = grab_cache_page_write_begin(mapping, 0, flags);
 	if (!page) {
-- 
1.7.1

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