Kernel/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2025-01-17 18:56:24 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

mm/swapfile: do not sleep with a spin lock held

Browse Source 
commit b11a76b37a5aa7b07c3e3eeeaae20b25475bddd3 upstream.

We can't call kvfree() with a spin lock held, so defer it.  Fixes a
might_sleep() runtime warning.

Fixes: 873d7bcfd066 ("mm/swapfile.c: use kvzalloc for swap_info_struct allocation")
Signed-off-by: Qian Cai <qcai@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20201202151549.10350-1-qcai@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Qian Cai 2020-12-05 22:14:55 -08:00 committed by Greg Kroah-Hartman
parent 7517a38342
commit 2498ae2460
1 changed files with 3 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
mm/swapfile.c
View File

@ -2825,6 +2825,7 @@ late_initcall(max_swapfiles_check);
static struct swap_info_struct *alloc_swap_info(void)
{
struct swap_info_struct *p;
struct swap_info_struct *defer = NULL;
unsigned int type;
int i;
int size = sizeof(*p) + nr_node_ids * sizeof(struct plist_node);
@ -2854,7 +2855,7 @@ static struct swap_info_struct *alloc_swap_info(void)
smp_wmb();
WRITE_ONCE(nr_swapfiles, nr_swapfiles + 1);
} else {
kvfree(p);
defer = p;
p = swap_info[type];
/*
* Do not memset this entry: a racing procfs swap_next()
@ -2867,6 +2868,7 @@ static struct swap_info_struct *alloc_swap_info(void)
plist_node_init(&p->avail_lists[i], 0);
p->flags = SWP_USED;
spin_unlock(&swap_lock);
kvfree(defer);
spin_lock_init(&p->lock);
spin_lock_init(&p->cont_lock);