Hi Ted,
do you plan on merging my fixes for writev filesystem corruption and
64-bit quota patches? The writev patch is independent of any other patch
and should go in ASAP, 64-bit quota patch depends on generic quota code
change so either I can merge it or you can merge a bit later (it's a small
change for ext4).
The patches were sent as:
http://marc.info/?l=linux-ext4&m=125978147226649&w=3
(writev corruption fix - it has a minor whitespace bug so I'm attaching a
version with that bug fixed)
http://marc.info/?l=linux-ext4&m=125978717902673&w=3
(64-bit quota support)
Honza
>From 8bd74d5ced949f276e51d770092bff576d42fa79 Mon Sep 17 00:00:00 2001
From: Jan Kara <jack@xxxxxxx>
Date: Wed, 2 Dec 2009 20:05:23 +0100
Subject: [PATCH 2/3] ext4: Fix data / filesystem corruption when write fails to copy data
When ext4_write_begin fails after allocating some blocks or
generic_perform_write fails to copy data to write, we truncate blocks already
instantiated beyond i_size. Although these blocks were never inside i_size, we
have to truncate pagecache of these blocks so that corresponding buffers get
unmapped. Otherwise subsequent __block_prepare_write (called because we are
retrying the write) will find the buffers mapped, not call ->get_block, and
thus the page will be backed by already freed blocks leading to filesystem and
data corruption.
Signed-off-by: Jan Kara <jack@xxxxxxx>
---
fs/ext4/inode.c | 20 +++++++++++++++-----
1 files changed, 15 insertions(+), 5 deletions(-)
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 2c8caa5..e802988 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1534,6 +1534,16 @@ static int do_journal_get_write_access(handle_t *handle,
return ext4_journal_get_write_access(handle, bh);
}
+/*
+ * Truncate blocks that were not used by write. We have to truncate the
+ * pagecache as well so that corresponding buffers get properly unmapped.
+ */
+static void ext4_truncate_failed_write(struct inode *inode)
+{
+ truncate_inode_pages(inode->i_mapping, inode->i_size);
+ ext4_truncate(inode);
+}
+
static int ext4_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
@@ -1599,7 +1609,7 @@ retry:
ext4_journal_stop(handle);
if (pos + len > inode->i_size) {
- ext4_truncate(inode);
+ ext4_truncate_failed_write(inode);
/*
* If truncate failed early the inode might
* still be on the orphan list; we need to
@@ -1709,7 +1719,7 @@ static int ext4_ordered_write_end(struct file *file,
ret = ret2;
if (pos + len > inode->i_size) {
- ext4_truncate(inode);
+ ext4_truncate_failed_write(inode);
/*
* If truncate failed early the inode might still be
* on the orphan list; we need to make sure the inode
@@ -1751,7 +1761,7 @@ static int ext4_writeback_write_end(struct file *file,
ret = ret2;
if (pos + len > inode->i_size) {
- ext4_truncate(inode);
+ ext4_truncate_failed_write(inode);
/*
* If truncate failed early the inode might still be
* on the orphan list; we need to make sure the inode
@@ -1814,7 +1824,7 @@ static int ext4_journalled_write_end(struct file *file,
if (!ret)
ret = ret2;
if (pos + len > inode->i_size) {
- ext4_truncate(inode);
+ ext4_truncate_failed_write(inode);
/*
* If truncate failed early the inode might still be
* on the orphan list; we need to make sure the inode
@@ -3091,7 +3101,7 @@ retry:
* i_size_read because we hold i_mutex.
*/
if (pos + len > inode->i_size)
- ext4_truncate(inode);
+ ext4_truncate_failed_write(inode);
}
if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
--
1.6.4.2
