path: root/Documentation/scsi
diff options
authorAhmed S. Darwish <>2021-01-18 11:09:39 +0100
committerMartin K. Petersen <>2021-01-22 21:31:07 -0500
commitc2d0f1a65ab9fbabebb463bf36f50ea8f4633386 (patch)
treea9a75b2cce006e15d245317588117efc05d1645d /Documentation/scsi
parent121181f3f839c29d8dd9fdc3cc9babbdc74227f8 (diff)
scsi: libsas: Introduce a _gfp() variant of event notifiers
sas_alloc_event() uses in_interrupt() to decide which allocation should be used. The usage of in_interrupt() in drivers is phased out and Linus clearly requested that code which changes behaviour depending on context should either be separated or the context be conveyed in an argument passed by the caller, which usually knows the context. The in_interrupt() check is also only partially correct, because it fails to choose the correct code path when just preemption or interrupts are disabled. For example, as in the following call chain: 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 Introduce sas_alloc_event_gfp(), sas_notify_port_event_gfp(), and sas_notify_phy_event_gfp(), which all behave like the non _gfp() variants but use a caller-passed GFP mask for allocations. For bisectability, all callers will be modified first to pass GFP context, then the non _gfp() libsas API variants will be modified to take a gfp_t by default. Link: Fixes: 1c393b970e0f ("scsi: libsas: Use dynamic alloced work to avoid sas event lost") Cc: Jason Yan <> Reviewed-by: John Garry <> Signed-off-by: Ahmed S. Darwish <> Signed-off-by: Martin K. Petersen <>
Diffstat (limited to 'Documentation/scsi')
1 files changed, 2 insertions, 0 deletions
diff --git a/Documentation/scsi/libsas.rst b/Documentation/scsi/libsas.rst
index 6722e352444b..ea63ab3a9216 100644
--- a/Documentation/scsi/libsas.rst
+++ b/Documentation/scsi/libsas.rst
@@ -191,6 +191,8 @@ The event interface::
/* LLDD calls these to notify the class of an event. */
void sas_notify_port_event(struct sas_phy *, enum port_event);
void sas_notify_phy_event(struct sas_phy *, enum phy_event);
+ void sas_notify_port_event_gfp(struct sas_phy *, enum port_event, gfp_t);
+ void sas_notify_phy_event_gfp(struct sas_phy *, enum phy_event, gfp_t);
The port notification::