[PATCH v2 04/19] scsi: mvsas: Pass gfp_t flags to libsas event notifiers

Ahmed S. Darwish
2021-01-12T11:08:06Z

mvsas calls the non _gfp version of the libsas event notifiers API,
leading to the buggy call chains below:

mvsas/mv_sas.c: mvs_work_queue() [process context]
spin_lock_irqsave(mvs_info::lock, )
-> libsas/sas_event.c: sas_notify_phy_event()
-> sas_alloc_event()
-> in_interrupt() = false
-> invalid GFP_KERNEL allocation
-> libsas/sas_event.c: sas_notify_port_event()
-> sas_alloc_event()
-> in_interrupt() = false
-> invalid GFP_KERNEL allocation

Use the new event notifiers API instead, which requires callers to
explicitly pass the gfp_t memory allocation flags.

Below are context analysis for the modified functions:

=> mvs_bytes_dmaed():

Since it is invoked from both process and atomic contexts, let its
callers pass the gfp_t flags. Call chains:

scsi_scan.c: do_scsi_scan_host() [has msleep()]
-> shost->hostt->scan_start()
-> [mvsas/mv_init.c: Scsi_Host::scsi_host_template .scan_start = mvs_scan_start()]
-> mvsas/mv_sas.c: mvs_scan_start()
-> mvs_bytes_dmaed(..., GFP_KERNEL)

mvsas/mv_sas.c: mvs_work_queue()
spin_lock_irqsave(mvs_info::lock,)
-> mvs_bytes_dmaed(..., GFP_ATOMIC)

mvsas/mv_64xx.c: mvs_64xx_isr() || mvsas/mv_94xx.c: mvs_94xx_isr()
-> mvsas/mv_chips.h: mvs_int_full()
-> mvsas/mv_sas.c: mvs_int_port()
-> mvs_bytes_dmaed(..., GFP_ATOMIC);

=> mvs_work_queue():

Invoked from process context, but it calls all the libsas event notifier
APIs under a spin_lock_irqsave(). Pass GFP_ATOMIC.

Fixes: 1c393b970e0f ("scsi: libsas: Use dynamic alloced work to avoid sas event lost")
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Cc: John Garry <john.garry@huawei.com>
Cc: Jason Yan <yanaijie@huawei.com>
---
drivers/scsi/mvsas/mv_sas.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/scsi/mvsas/mv_sas.c b/drivers/scsi/mvsas/mv_sas.c
index e5e3e95f78b0..e80f760f8abd 100644
--- a/drivers/scsi/mvsas/mv_sas.c
+++ b/drivers/scsi/mvsas/mv_sas.c
@@ -216,7 +216,7 @@ void mvs_set_sas_addr(struct mvs_info *mvi, int port_id, u32 off_lo,
MVS_CHIP_DISP->write_port_cfg_data(mvi, port_id, hi);
}

-static void mvs_bytes_dmaed(struct mvs_info *mvi, int i)
+static void mvs_bytes_dmaed(struct mvs_info *mvi, int i, gfp_t gfp_flags)
{
struct mvs_phy *phy = &mvi->phy[i];
struct asd_sas_phy *sas_phy = &phy->sas_phy;
@@ -229,7 +229,7 @@ static void mvs_bytes_dmaed(struct mvs_info *mvi, int i)
return;
}

- sas_notify_phy_event(sas_phy, PHYE_OOB_DONE);
+ sas_notify_phy_event_gfp(sas_phy, PHYE_OOB_DONE, gfp_flags);

if (sas_phy->phy) {
struct sas_phy *sphy = sas_phy->phy;
@@ -261,7 +261,7 @@ static void mvs_bytes_dmaed(struct mvs_info *mvi, int i)

sas_phy->frame_rcvd_size = phy->frame_rcvd_size;

- sas_notify_port_event(sas_phy, PORTE_BYTES_DMAED);
+ sas_notify_port_event_gfp(sas_phy, PORTE_BYTES_DMAED, gfp_flags);
}

void mvs_scan_start(struct Scsi_Host *shost)
@@ -277,7 +277,7 @@ void mvs_scan_start(struct Scsi_Host *shost)
for (j = 0; j < core_nr; j++) {
mvi = ((struct mvs_prv_info *)sha->lldd_ha)->mvi[j];
for (i = 0; i < mvi->chip->n_phy; ++i)
- mvs_bytes_dmaed(mvi, i);
+ mvs_bytes_dmaed(mvi, i, GFP_KERNEL);
}
mvs_prv->scan_finished = 1;
}
@@ -1892,20 +1892,20 @@ static void mvs_work_queue(struct work_struct *work)
if (!(tmp & PHY_READY_MASK)) {
sas_phy_disconnected(sas_phy);
mvs_phy_disconnected(phy);
- sas_notify_phy_event(sas_phy,
- PHYE_LOSS_OF_SIGNAL);
+ sas_notify_phy_event_gfp(sas_phy,
+ PHYE_LOSS_OF_SIGNAL, GFP_ATOMIC);
mv_dprintk("phy%d Removed Device\n", phy_no);
} else {
MVS_CHIP_DISP->detect_porttype(mvi, phy_no);
mvs_update_phyinfo(mvi, phy_no, 1);
- mvs_bytes_dmaed(mvi, phy_no);
+ mvs_bytes_dmaed(mvi, phy_no, GFP_ATOMIC);
mvs_port_notify_formed(sas_phy, 0);
mv_dprintk("phy%d Attached Device\n", phy_no);
}
}
} else if (mwq->handler & EXP_BRCT_CHG) {
phy->phy_event &= ~EXP_BRCT_CHG;
- sas_notify_port_event(sas_phy, PORTE_BROADCAST_RCVD);
+ sas_notify_port_event_gfp(sas_phy, PORTE_BROADCAST_RCVD, GFP_ATOMIC);
mv_dprintk("phy%d Got Broadcast Change\n", phy_no);
}
list_del(&mwq->entry);
@@ -2022,7 +2022,7 @@ void mvs_int_port(struct mvs_info *mvi, int phy_no, u32 events)
mdelay(10);
}

- mvs_bytes_dmaed(mvi, phy_no);
+ mvs_bytes_dmaed(mvi, phy_no, GFP_ATOMIC);
/* whether driver is going to handle hot plug */
if (phy->phy_event & PHY_PLUG_OUT) {
mvs_port_notify_formed(&phy->sas_phy, 0);
--
2.30.0