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| author | Ahmed S. Darwish <a.darwish@linutronix.de> | 2021-01-18 11:09:39 +0100 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2021-01-23 03:31:07 +0100 |
| commit | c2d0f1a65ab9fbabebb463bf36f50ea8f4633386 (patch) | |
| tree | a9a75b2cce006e15d245317588117efc05d1645d /Documentation/scsi | |
| parent | scsi: libsas: Remove notifier indirection (diff) | |
| download | linux-c2d0f1a65ab9fbabebb463bf36f50ea8f4633386.tar.xz linux-c2d0f1a65ab9fbabebb463bf36f50ea8f4633386.zip | |
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: https://lore.kernel.org/r/20210118100955.1761652-4-a.darwish@linutronix.de
Fixes: 1c393b970e0f ("scsi: libsas: Use dynamic alloced work to avoid sas event lost")
Cc: Jason Yan <yanaijie@huawei.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'Documentation/scsi')
| -rw-r--r-- | Documentation/scsi/libsas.rst | 2 |
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:: |