diff options
| author | Jan Kara <jack@suse.cz> | 2009-12-01 16:53:06 +0100 |
|---|---|---|
| committer | Jan Kara <jack@suse.cz> | 2009-12-10 15:02:55 +0100 |
| commit | 68eb3db08344286733adac48304d9fb7a0e53b27 (patch) | |
| tree | 214133860fdb6ceac4adbeb621837df8c494f1fb | |
| parent | 5a20bdfcdc5c5e5f0647d8d99a998066ef5496ac (diff) | |
ext3: Fix data / filesystem corruption when write fails to copy data
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>
| -rw-r--r-- | fs/ext3/inode.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c index 2db95777890..ad14227f509 100644 --- a/fs/ext3/inode.c +++ b/fs/ext3/inode.c @@ -1151,6 +1151,16 @@ 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) @@ -1209,7 +1219,7 @@ 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; @@ -1304,7 +1314,7 @@ 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; } @@ -1330,7 +1340,7 @@ 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; } @@ -1383,7 +1393,7 @@ 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; } |