Re: Mount ext3 with barrier=1 doesn't send real barrier bio?

From: OGAWA Hirofumi
Date: Thu Aug 21 2008 - 18:24:22 EST


Eric Sandeen <sandeen@xxxxxxxxxxx> writes:

>> --- a/fs/buffer.c
>> +++ b/fs/buffer.c
>> @@ -2926,16 +2926,16 @@ int submit_bh(int rw, struct buffer_head * bh)
>> BUG_ON(!buffer_mapped(bh));
>> BUG_ON(!bh->b_end_io);
>>
>> - if (buffer_ordered(bh) && (rw == WRITE))
>> - rw = WRITE_BARRIER;
>> -
>> /*
>> * Only clear out a write error when rewriting, should this
>> * include WRITE_SYNC as well?
>> */
>> - if (test_set_buffer_req(bh) && (rw == WRITE || rw == WRITE_BARRIER))
>> + if (test_set_buffer_req(bh) && rw == WRITE)
>> clear_buffer_write_io_error(bh);

This should be ((rw & RW_MASK) == WRITE) too? Anyway, this seems change
behavior of submit_bh(WRITE_BARRIER) (maybe reiserfs only), it wouldn't
be your intent...

>> + if (buffer_ordered(bh) && ((rw & RW_MASK) == WRITE))
>> + rw |= (1 << BIO_RW_BARRIER);
>> +
>> /*
>> * from here on down, it's all bio -- do the initial mapping,
>> * submit_bio -> generic_make_request may further map this bio around
--
OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>
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