Re: dm_write_invis() blocking problem

[Dean Roehrich <roehrich@xxxxxxxxxxxxxxxxxxxxxx>]

>From:  Mike Montour <mmontour@xxxxxxxxxx>
>Dean Roehrich wrote:
>
>> I'm currently testing the following patch, which should alleviate the 
>> hang.
>>
>>The problem is that a thread was able to get into the dmapi queues while
>>holding a resource (i_sem, in this case).
>>
>>Dean
>>  
>>
>Thank you for the patch. It fixes my DM_EVENT_WRITE problem. However,
>I can trigger a similar situation by calling dm_write_invis() while 
>processing
>a TRUNCATE event. A co-worker has been helping me test this using KDB,
>and I've attached his notes.

Okay, so do_truncate() is grabbing both i_sem and i_alloc_sem in current 2.4.

Thanks



>Also, when the patch is applied to a current checkout of the SGI CVS tree
>(pserver:cvs@xxxxxxxxxxx:/cvs), there is a link failure:
>
>fs/fs.o: In function `xfs_dm_send_data_event':
>fs/fs.o(.text+0xac8fb): undefined reference to `do_up_read'
>fs/fs.o(.text+0xac94b): undefined reference to `do_down_read'

sorry, I've been building against 2.4.21 ...don't ask why

Dean