| Message ID | 20220119055955.931355-1-chi.minghao@zte.com.cn (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drivers/scsi/csiostor: do not sleep with a spin lock held | expand |
On 1/19/22 14:59, cgel.zte@gmail.com wrote: > From: Minghao Chi <chi.minghao@zte.com.cn> > > The might_sleep_if function in the mempool_alloc > may cause a sleep lock.We can't mempool_alloc() > with a spin lock held, so bring it up front. But the allocation is GFP_ATOMIC, which does not have __GFP_DIRECT_RECLAIM, so how come mempool_alloc() triggers the might_sleep() warning ? > > Reported-by: Zeal Robot <zealci@zte.com.cn> > Signed-off-by: Minghao Chi <chi.minghao@zte.com.cn> > Signed-off-by: CGEL ZTE <cgel.zte@gmail.com> > --- > drivers/scsi/csiostor/csio_attr.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/scsi/csiostor/csio_attr.c b/drivers/scsi/csiostor/csio_attr.c > index 200e50089711..3d4ab439c756 100644 > --- a/drivers/scsi/csiostor/csio_attr.c > +++ b/drivers/scsi/csiostor/csio_attr.c > @@ -424,8 +424,8 @@ csio_fcoe_alloc_vnp(struct csio_hw *hw, struct csio_lnode *ln) > > /* Issue VNP cmd to alloc vport */ > /* Allocate Mbox request */ > - spin_lock_irq(&hw->lock); > mbp = mempool_alloc(hw->mb_mempool, GFP_ATOMIC); > + spin_lock_irq(&hw->lock); > if (!mbp) { > CSIO_INC_STATS(hw, n_err_nomem); > ret = -ENOMEM; > @@ -505,8 +505,8 @@ csio_fcoe_free_vnp(struct csio_hw *hw, struct csio_lnode *ln) > /* Issue VNP cmd to free vport */ > /* Allocate Mbox request */ > > - spin_lock_irq(&hw->lock); > mbp = mempool_alloc(hw->mb_mempool, GFP_ATOMIC); > + spin_lock_irq(&hw->lock); > if (!mbp) { > CSIO_INC_STATS(hw, n_err_nomem); > ret = -ENOMEM;
The might_sleep_if(gfp_mask & __GFP_DIRECT_RECLAIM) in the mempool_alloc function uses __GFP_DIRECT_RECLAIM.
On 1/19/22 17:57, cgel.zte@gmail.com wrote: > > The might_sleep_if(gfp_mask & __GFP_DIRECT_RECLAIM) in the > mempool_alloc function uses __GFP_DIRECT_RECLAIM. But the call to mempool_alloc() specifies GFP_ATOMIC, which does not have __GFP_DIRECT_RECLAIM, so "gfp_mask & __GFP_DIRECT_RECLAIM" should be false, and the might_sleep_if() not triggering. How can you see the might sleep warning ?
Sorry, GFP_ATOMIC&__GFP_DIRECT_RECLAIM are indeed false
diff --git a/drivers/scsi/csiostor/csio_attr.c b/drivers/scsi/csiostor/csio_attr.c index 200e50089711..3d4ab439c756 100644 --- a/drivers/scsi/csiostor/csio_attr.c +++ b/drivers/scsi/csiostor/csio_attr.c @@ -424,8 +424,8 @@ csio_fcoe_alloc_vnp(struct csio_hw *hw, struct csio_lnode *ln) /* Issue VNP cmd to alloc vport */ /* Allocate Mbox request */ - spin_lock_irq(&hw->lock); mbp = mempool_alloc(hw->mb_mempool, GFP_ATOMIC); + spin_lock_irq(&hw->lock); if (!mbp) { CSIO_INC_STATS(hw, n_err_nomem); ret = -ENOMEM; @@ -505,8 +505,8 @@ csio_fcoe_free_vnp(struct csio_hw *hw, struct csio_lnode *ln) /* Issue VNP cmd to free vport */ /* Allocate Mbox request */ - spin_lock_irq(&hw->lock); mbp = mempool_alloc(hw->mb_mempool, GFP_ATOMIC); + spin_lock_irq(&hw->lock); if (!mbp) { CSIO_INC_STATS(hw, n_err_nomem); ret = -ENOMEM;