From: Qu Wenruo <quwenruo.btrfs@gmx.com>
To: dsterba@suse.cz, David Sterba <dsterba@suse.com>,
linux-btrfs@vger.kernel.org
Subject: Re: [PATCH 10/10] btrfs: add and use simple page/bio to inode/fs_info helpers
Date: Tue, 27 Jul 2021 06:26:47 +0800 [thread overview]
Message-ID: <cc110ee1-c1bf-2b83-b5db-f70468b159f7@gmx.com> (raw)
In-Reply-To: <20210726150953.GG5047@twin.jikos.cz>
On 2021/7/26 下午11:09, David Sterba wrote:
> On Mon, Jul 26, 2021 at 08:41:57PM +0800, Qu Wenruo wrote:
>>
>>
>> On 2021/7/26 下午8:15, David Sterba wrote:
>>> We have lots of places where we want to obtain inode from page, fs_info
>>> from page and open code the pointer chains.
>>
>> All those inode/fs_info grabbing from just a page is dangerous.
>>
>> If an anonymous page is passed in unintentionally, it can easily crash
>> the system.
>>
>> Thus at least some ASSERT() here is a must to me.
>
> But we can only check if the pointer is valid, any page can have a valid
> pointer but not our fs_info. If it crashes on an unexpected page than
> what can we do in the code anyway?
>
What I mean is to check page->mapping for the page passed in.
Indeed we can't do anything when we hit a page with NULL mapping
pointer, but that's a code bug.
An ASSERT() would make us developer aware what's going wrong and to fix
the bug.
Thanks,
Qu
next prev parent reply other threads:[~2021-07-26 22:26 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-26 12:15 [PATCH 00/10] Misc small cleanups David Sterba
2021-07-26 12:15 ` [PATCH 01/10] btrfs: switch uptodate to bool in btrfs_writepage_endio_finish_ordered David Sterba
2021-07-26 12:23 ` Qu Wenruo
2021-07-26 12:15 ` [PATCH 02/10] btrfs: remove uptodate parameter from btrfs_dec_test_first_ordered_pending David Sterba
2021-07-26 12:24 ` Qu Wenruo
2021-07-26 12:15 ` [PATCH 03/10] btrfs: make btrfs_next_leaf static inline David Sterba
2021-07-26 12:25 ` Qu Wenruo
2021-07-26 12:15 ` [PATCH 04/10] btrfs: tree-checker: use table values for stripe checks David Sterba
2021-07-26 12:29 ` Qu Wenruo
2021-07-26 14:47 ` David Sterba
2021-07-26 12:15 ` [PATCH 05/10] btrfs: tree-checker: add missing stripe checks for raid1c3/4 profiles David Sterba
2021-07-26 12:29 ` Qu Wenruo
2021-07-26 12:15 ` [PATCH 06/10] btrfs: uninline btrfs_bg_flags_to_raid_index David Sterba
2021-07-26 12:34 ` Qu Wenruo
2021-07-26 15:06 ` David Sterba
2021-07-26 12:15 ` [PATCH 07/10] btrfs: merge alloc_device helpers David Sterba
2021-07-26 12:35 ` Qu Wenruo
2021-07-26 12:15 ` [PATCH 08/10] btrfs: simplify data stripe calculation helpers David Sterba
2021-07-26 12:38 ` Qu Wenruo
2021-07-26 15:06 ` David Sterba
2021-07-26 22:23 ` Qu Wenruo
2021-07-27 8:39 ` David Sterba
2021-07-27 9:32 ` Qu Wenruo
2021-07-26 12:15 ` [PATCH 09/10] btrfs: constify and cleanup variables comparators David Sterba
2021-07-26 12:15 ` [PATCH 10/10] btrfs: add and use simple page/bio to inode/fs_info helpers David Sterba
2021-07-26 12:41 ` Qu Wenruo
2021-07-26 15:09 ` David Sterba
2021-07-26 22:26 ` Qu Wenruo [this message]
2021-07-27 8:45 ` David Sterba
2021-07-27 9:42 ` Qu Wenruo
2021-07-27 14:44 ` David Sterba
2021-07-27 15:03 ` [PATCH v2 " David Sterba
2021-07-28 0:12 ` Qu Wenruo
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