On Wed, Oct 14, 2015 at 3:18 AM, Kinglong Mee <kinglongmee@xxxxxxxxx> wrote: > On 10/13/2015 21:45, Trond Myklebust wrote: >> On Tue, Oct 13, 2015 at 8:45 AM, Kinglong Mee <kinglongmee@xxxxxxxxx> wrote: >>> ping ... >>> >>> What's your opinion about this problem ? >>> >>> If read/write of block layout file with bad length (res.count != arg.count), >>> should nfs retry? NFS try to call rpc_restart_call_prepare() right now, >>> that cause a panic with uninitialized task. >> >> The client should not be attempting to read more data than what was >> requested by the O_DIRECT read request. It should be strictly >> respecting the boundaries of the user buffer that was supplied. > > Yes, that's right. > >> Any idea why this is happening? > > As post before, bl_read_pagelist() return a longer result that causes the panic. > >>>> [ 1004.001842] bl_read_pagelist enter nr_pages 1 offset 2048 count 2048 >>>> [ 1004.002110] bl_read_pagelist: pg_offset 2048 >>>> [ 1004.002370] bl_read_pagelist: pg_len 2048 is_dio >>>> [ 1004.002617] bl_read_pagelist: pg_len 2048 after do_add_page_to_bio >>>> [ 1004.002853] bl_read_pagelist: 2048 4096 "(isect << SECTOR_SHIFT) < header->inode->i_size" >>>> [ 1004.003774] NFS: nfs_pgio_result: 0, (status 0), tk_ops (null) >>>> [ 1004.003989] --> nfs4_read_done >>>> [ 1004.004224] nfs_readpage_done: 0 >>>> [ 1004.004459] nfs_pgio_result: 0 >>>> [ 1004.004691] nfs_readpage_result: eof 0, res.count 4096, args.count 2048 >>>> [ 1004.004926] nfs_readpage_retry: tk_ops (null) Right, but that means one of two things: Either we need to fix bl_read_pagelist, or we need to fall back to read-through-MDS in this case. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
