[linux-next] scsi_attach_vpd() warning at mm/page_alloc.c:2497

[Sergey Senozhatsky <sergey.senozhatsky@gmail.com>]

Hello,

[    1.971778] ------------[ cut here ]------------
[    1.971960] WARNING: CPU: 1 PID: 6 at mm/page_alloc.c:2497 __alloc_pages_nodemask+0x1b9/0x693()
[    1.972246] Modules linked in: sd_mod ahci
[    1.972604] CPU: 1 PID: 6 Comm: kworker/u8:0 Not tainted 3.14.0-rc8-next-20140327-dbg-dirty #202
[    1.972890] Hardware name: Acer             Aspire 5741G    /Aspire 5741G    , BIOS V1.20 02/08/2011
[    1.973182] Workqueue: events_unbound async_run_entry_fn
[    1.973417]  0000000000000000 ffff8801534d5af0 ffffffff813ad822 0000000000000000
[    1.973994]  ffff8801534d5b28 ffffffff8103c03c ffffffff810ad4e5 00000000001000d0
[    1.974529]  ffffffff81656fc8 0000000000000000 ffffffff81656fc0 ffff8801534d5b38
[    1.975125] Call Trace:
[    1.975306]  [<ffffffff813ad822>] dump_stack+0x4e/0x7a
[    1.975488]  [<ffffffff8103c03c>] warn_slowpath_common+0x75/0x8e
[    1.975670]  [<ffffffff810ad4e5>] ? __alloc_pages_nodemask+0x1b9/0x693
[    1.975853]  [<ffffffff8103c0f4>] warn_slowpath_null+0x15/0x17
[    1.976035]  [<ffffffff810ad4e5>] __alloc_pages_nodemask+0x1b9/0x693
[    1.976220]  [<ffffffff81074220>] ? console_unlock+0x2dd/0x2fa
[    1.976404]  [<ffffffff812a08be>] ? scsi_execute_req_flags+0x9c/0xb3
[    1.976587]  [<ffffffff810ad9d1>] __get_free_pages+0x12/0x3f
[    1.976771]  [<ffffffff810d5c66>] __kmalloc+0x37/0x112
[    1.976951]  [<ffffffff8129b5f4>] scsi_attach_vpd+0x41/0x1a8
[    1.977133]  [<ffffffff812a3d81>] scsi_probe_and_add_lun+0x8ec/0xa21
[    1.977317]  [<ffffffff812a40f8>] __scsi_add_device+0xce/0x10a
[    1.977501]  [<ffffffff812b109a>] ata_scsi_scan_host+0x60/0x142
[    1.977683]  [<ffffffff812ad6e9>] async_port_probe+0x45/0x4a
[    1.977873]  [<ffffffff81057e18>] async_run_entry_fn+0x5a/0x110
[    1.978061]  [<ffffffff8104ee52>] process_one_work+0x1c9/0x2e9
[    1.978243]  [<ffffffff8104f3ec>] worker_thread+0x1d3/0x2bd
[    1.978424]  [<ffffffff8104f219>] ? rescuer_thread+0x27d/0x27d
[    1.978606]  [<ffffffff81053ab4>] kthread+0xd6/0xde
[    1.978786]  [<ffffffff810539de>] ? kthread_create_on_node+0x162/0x162
[    1.978970]  [<ffffffff813b2efc>] ret_from_fork+0x7c/0xb0
[    1.979151]  [<ffffffff810539de>] ? kthread_create_on_node+0x162/0x162
[    1.979334] ---[ end trace ca7c5bd74b0dca21 ]---


scsi_attach_vpd() (at pg0 label) attempts to firstly allocate 255 and later 134217730 bytes.



---

general question,

scsi_attach_vpd() is sure that scsi_vpd_inquiry() returns `ret < 0' in case of
an error and `ret > 0' otherwise:

	"Returns size of the vpd page on success or a negative error number."

while this is not exactly true.

scsi_vpd_inquiry() indeed can return -EINVAL, but usually it returns
scsi_execute_req()->scsi_execute_req_flags()->scsi_execute() status, which
has different error indication and can be, e.g. for failed blk_get_request()
in scsi_execute() or failed sense kzalloc() in scsi_execute_req_flags(),
`DRIVER_ERROR << 24'.


	-ss