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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Hulk Robot <hulkci@huawei.com>,
        James Smart <jsmart2021@gmail.com>,
        Yang Yingliang <yangyingliang@huawei.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>
Subject: [PATCH 5.15 083/171] scsi: elx: efct: Dont use GFP_KERNEL under spin lock
Date:   Mon, 31 Jan 2022 11:55:48 +0100
Message-Id: <20220131105232.832270331@linuxfoundation.org>
In-Reply-To: <20220131105229.959216821@linuxfoundation.org>
References: <20220131105229.959216821@linuxfoundation.org>
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From: Yang Yingliang <yangyingliang@huawei.com>

commit 61263b3a11a2594b4e898f166c31162236182b5c upstream.

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

Link: https://lore.kernel.org/r/20220111012441.3232527-1-yangyingliang@huawei.com
Fixes: 8f406ef72859 ("scsi: elx: libefc: Extended link Service I/O handling")
Reported-by: Hulk Robot <hulkci@huawei.com>
Reviewed-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/scsi/elx/libefc/efc_els.c |    8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

--- 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 *n
 
 	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 *n
 					      &els->io.req.phys, GFP_DMA);
 	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 *n
 
 		/* 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;
 }