From: Theodore Ts'o <tytso@mit.edu>
To: Zheng Liu <gnehzuil.liu@gmail.com>
Cc: linux-ext4@vger.kernel.org, Zheng Liu <wenqing.lz@taobao.com>,
Dmitry Monakhov <dmonakhov@openvz.org>
Subject: Re: [PATCH v2 3/5] ext4: fix wrong m_len value after unwritten extent conversion
Date: Sun, 10 Mar 2013 21:07:18 -0400 [thread overview]
Message-ID: <20130311010718.GC10090@thunk.org> (raw)
In-Reply-To: <1362579435-6333-4-git-send-email-wenqing.lz@taobao.com>
On Wed, Mar 06, 2013 at 10:17:13PM +0800, Zheng Liu wrote:
> From: Zheng Liu <wenqing.lz@taobao.com>
>
> We always assume that the return value of ext4_ext_map_blocks is equal
> to map->m_len
Note that in general, this is _never_ safe to assume. There are a
number of times when the number of blocks mapped is less than what the
caller originally requested, both when allocating blocks (and there
isn't the requestd number of contiguous blocks available), and when
EXT4_GET_BLOCKS_CREATE is not set.
- Ted
next prev parent reply other threads:[~2013-03-11 1:07 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-06 14:17 [PATCH v2 0/5] ext4: try to fix up es regressions Zheng Liu
2013-03-06 14:17 ` [PATCH v2 1/5] ext4: improve ext4_es_can_be_merged() to avoid a potential overflow Zheng Liu
2013-03-11 0:43 ` Theodore Ts'o
2013-03-11 6:03 ` Zheng Liu
2013-03-06 14:17 ` [PATCH v2 2/5] ext4: add self-testing infrastructure to do a sanity check Zheng Liu
2013-03-07 15:41 ` Dmitry Monakhov
2013-03-08 13:01 ` Zheng Liu
2013-03-11 1:01 ` Theodore Ts'o
2013-03-06 14:17 ` [PATCH v2 3/5] ext4: fix wrong m_len value after unwritten extent conversion Zheng Liu
2013-03-07 15:42 ` Dmitry Monakhov
2013-03-11 1:07 ` Theodore Ts'o [this message]
2013-03-11 5:47 ` Zheng Liu
2013-03-13 1:57 ` Theodore Ts'o
2013-03-13 2:14 ` Theodore Ts'o
2013-03-13 8:53 ` Zheng Liu
2013-03-06 14:17 ` [PATCH v2 4/5] ext4: update extent status tree after an extent is zeroed out Zheng Liu
2013-03-07 15:55 ` Dmitry Monakhov
2013-03-08 13:14 ` Zheng Liu
2013-03-06 14:17 ` [PATCH v2 5/5] ext4: fix wrong the number of the allocted blocks in ext4_split_extent Zheng Liu
2013-03-06 22:58 ` Dev branch regressions Theodore Ts'o
2013-03-07 2:40 ` Zheng Liu
2013-03-07 6:47 ` Lukáš Czerner
2013-03-07 11:54 ` Zheng Liu
2013-03-07 16:08 ` [PATCH v2 0/5] ext4: try to fix up es regressions Dmitry Monakhov
2013-03-08 13:18 ` Zheng Liu
2013-03-11 2:11 ` Theodore Ts'o
2013-03-11 6:23 ` Zheng Liu
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