Re: [PATCH] f2fs: fix a deadlock in fsync

From: Jaegeuk Kim
Date: Wed Aug 07 2013 - 05:43:47 EST


Hi Jin,

2013-08-07 (ì), 12:23 +0800, Jim Xu:
> Hi Kim,
>
> The patch sounds good to me.
>
> BTW, as in the deadlock situation I noticed, I did not find any thread was doing checkpoint at that moment. The bdi writeback thread and the fsync user thread was not. Neither was the background f2fs_gc thread because there had enough free segments. Meanwhile, another user thread was blocked in the f2fs_sync_file->sync_node_pages, which, I think, is not a factor contributing to the deadlock.

I indicated one possible scenario.
As you described, many fsync calls can also consume all the fs_lock too.
Thanks,

--
Jaegeuk Kim
Samsung

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