Patch "scsi: elx: efct: Don't use GFP_KERNEL under spin lock" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    scsi: elx: efct: Don't use GFP_KERNEL under spin lock

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     scsi-elx-efct-don-t-use-gfp_kernel-under-spin-lock.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 152048e551ef9efa68c219e62fd2adeee06a1ba5
Author: Yang Yingliang <yangyingliang@xxxxxxxxxx>
Date:   Tue Jan 11 09:24:41 2022 +0800

    scsi: elx: efct: Don't use GFP_KERNEL under spin lock
    
    [ Upstream commit 61263b3a11a2594b4e898f166c31162236182b5c ]
    
    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@xxxxxxxxxx
    Fixes: 8f406ef72859 ("scsi: elx: libefc: Extended link Service I/O handling")
    Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
    Reviewed-by: James Smart <jsmart2021@xxxxxxxxx>
    Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx>
    Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/scsi/elx/libefc/efc_els.c b/drivers/scsi/elx/libefc/efc_els.c
index 24db0accb256e..5f690378fe9a9 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_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 *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;
 }