summaryrefslogtreecommitdiff
path: root/fs
diff options
context:
space:
mode:
authorJan Kara <jack@suse.cz>2009-12-01 16:53:06 +0100
committerGreg Kroah-Hartman <gregkh@suse.de>2009-12-18 13:44:18 -0800
commite5a1a67df493b4c14a6e1e795b861d0dd8226529 (patch)
tree6355b9672f591205255d14c161b35d7e632331e6 /fs
parent1c1f916747265cd65ba1896c20a93034c6c1ec17 (diff)
ext3: Fix data / filesystem corruption when write fails to copy data
commit 68eb3db08344286733adac48304d9fb7a0e53b27 upstream. When ext3_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. Reported-by: James Y Knight <foom@fuhm.net> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'fs')
-rw-r--r--fs/ext3/inode.c18
1 files changed, 14 insertions, 4 deletions
diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
index b49908a167ae..6244b0cb98c5 100644
--- a/fs/ext3/inode.c
+++ b/fs/ext3/inode.c
@@ -1137,6 +1137,16 @@ static int do_journal_get_write_access(handle_t *handle,
return ext3_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 ext3_truncate_failed_write(struct inode *inode)
+{
+ truncate_inode_pages(inode->i_mapping, inode->i_size);
+ ext3_truncate(inode);
+}
+
static int ext3_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
@@ -1195,7 +1205,7 @@ write_begin_failed:
unlock_page(page);
page_cache_release(page);
if (pos + len > inode->i_size)
- ext3_truncate(inode);
+ ext3_truncate_failed_write(inode);
}
if (ret == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
goto retry;
@@ -1290,7 +1300,7 @@ static int ext3_ordered_write_end(struct file *file,
page_cache_release(page);
if (pos + len > inode->i_size)
- ext3_truncate(inode);
+ ext3_truncate_failed_write(inode);
return ret ? ret : copied;
}
@@ -1316,7 +1326,7 @@ static int ext3_writeback_write_end(struct file *file,
page_cache_release(page);
if (pos + len > inode->i_size)
- ext3_truncate(inode);
+ ext3_truncate_failed_write(inode);
return ret ? ret : copied;
}
@@ -1369,7 +1379,7 @@ static int ext3_journalled_write_end(struct file *file,
page_cache_release(page);
if (pos + len > inode->i_size)
- ext3_truncate(inode);
+ ext3_truncate_failed_write(inode);
return ret ? ret : copied;
}