2022-01-11 01:19:25

by Yang Yingliang

Subject: [PATCH -next v2] scsi: efct: don't use GFP_KERNEL under spin lock

GFP_KERNEL/GFP_DMA can't be used under a spin lock, according the
comment of els_ios_lock, it's used to protect els ios list, so we
can move down the spin lock to avoid using this flag under the lock.

Reported-by: Hulk Robot <[email protected]>
Fixes: 8f406ef72859 ("scsi: elx: libefc: Extended link Service I/O handling")
Signed-off-by: Yang Yingliang <[email protected]>
---
v2:
move up unlock to just protect list_add_tail()
---
drivers/scsi/elx/libefc/efc_els.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/drivers/scsi/elx/libefc/efc_els.c b/drivers/scsi/elx/libefc/efc_els.c
index 7bb4f9aad2c8..84bc81d7ce76 100644
--- a/drivers/scsi/elx/libefc/efc_els.c
+++ b/drivers/scsi/elx/libefc/efc_els.c
@@ -46,18 +46,14 @@ efc_els_io_alloc_size(struct efc_node *node, u32 reqlen, u32 rsplen)

efc = node->efc;

- spin_lock_irqsave(&node->els_ios_lock, flags);
-
if (!node->els_io_enabled) {
efc_log_err(efc, "els io alloc disabled\n");
- spin_unlock_irqrestore(&node->els_ios_lock, flags);
return NULL;
}

els = mempool_alloc(efc->els_io_pool, GFP_ATOMIC);
if (!els) {
atomic_add_return(1, &efc->els_io_alloc_failed_count);
- spin_unlock_irqrestore(&node->els_ios_lock, flags);
return NULL;
}

@@ -74,7 +70,6 @@ efc_els_io_alloc_size(struct efc_node *node, u32 reqlen, u32 rsplen)
&els->io.req.phys, GFP_KERNEL);
if (!els->io.req.virt) {
mempool_free(els, efc->els_io_pool);
- spin_unlock_irqrestore(&node->els_ios_lock, flags);
return NULL;
}

@@ -94,10 +89,11 @@ efc_els_io_alloc_size(struct efc_node *node, u32 reqlen, u32 rsplen)

/* add els structure to ELS IO list */
INIT_LIST_HEAD(&els->list_entry);
+ spin_lock_irqsave(&node->els_ios_lock, flags);
list_add_tail(&els->list_entry, &node->els_ios_list);
+ spin_unlock_irqrestore(&node->els_ios_lock, flags);
}

- spin_unlock_irqrestore(&node->els_ios_lock, flags);
return els;
}

--
2.25.1

2022-01-12 19:30:48

by James Smart

Subject: Re: [PATCH -next v2] scsi: efct: don't use GFP_KERNEL under spin lock

On 1/10/2022 5:24 PM, Yang Yingliang wrote:
> GFP_KERNEL/GFP_DMA can't be used under a spin lock, according the
> comment of els_ios_lock, it's used to protect els ios list, so we
> can move down the spin lock to avoid using this flag under the lock.
>
> Reported-by: Hulk Robot <[email protected]>
> Fixes: 8f406ef72859 ("scsi: elx: libefc: Extended link Service I/O handling")
> Signed-off-by: Yang Yingliang <[email protected]>
> ---
> v2:
> move up unlock to just protect list_add_tail()
> ---
> drivers/scsi/elx/libefc/efc_els.c | 8 ++------
> 1 file changed, 2 insertions(+), 6 deletions(-)
>

Looks fine.

Reviewed-by: James Smart <[email protected]>

-- james

2022-01-21 14:47:51

by Martin K. Petersen

Subject: Re: [PATCH -next v2] scsi: efct: don't use GFP_KERNEL under spin lock

Yang,

> GFP_KERNEL/GFP_DMA can't be used under a spin lock, according the
> comment of els_ios_lock, it's used to protect els ios list, so we
> can move down the spin lock to avoid using this flag under the lock.

Applied to 5.17/scsi-staging, thanks!

--
Martin K. Petersen Oracle Linux Engineering

2022-01-25 08:56:04

by Martin K. Petersen

Subject: Re: [PATCH -next v2] scsi: efct: don't use GFP_KERNEL under spin lock

On Tue, 11 Jan 2022 09:24:41 +0800, Yang Yingliang wrote:

> GFP_KERNEL/GFP_DMA can't be used under a spin lock, according the
> comment of els_ios_lock, it's used to protect els ios list, so we
> can move down the spin lock to avoid using this flag under the lock.
>
>

Applied to 5.17/scsi-fixes, thanks!

[1/1] scsi: efct: don't use GFP_KERNEL under spin lock
https://git.kernel.org/mkp/scsi/c/61263b3a11a2

--
Martin K. Petersen Oracle Linux Engineering