Update Linux to v5.10.157

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.157.tar.xz

Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
Change-Id: I7b30d9e98d8c465d6b44de8e7433b4a40b3289ba
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index c63656c..a56f2b9 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3679,11 +3679,15 @@
 	 * need to be calculated.
 	 */
 	if (!order) {
-		long fast_free;
+		long usable_free;
+		long reserved;
 
-		fast_free = free_pages;
-		fast_free -= __zone_watermark_unusable_free(z, 0, alloc_flags);
-		if (fast_free > mark + z->lowmem_reserve[highest_zoneidx])
+		usable_free = free_pages;
+		reserved = __zone_watermark_unusable_free(z, 0, alloc_flags);
+
+		/* reserved may over estimate high-atomic reserves. */
+		usable_free -= min(usable_free, reserved);
+		if (usable_free > mark + z->lowmem_reserve[highest_zoneidx])
 			return true;
 	}
 
@@ -4318,6 +4322,30 @@
 EXPORT_SYMBOL_GPL(fs_reclaim_release);
 #endif
 
+/*
+ * Zonelists may change due to hotplug during allocation. Detect when zonelists
+ * have been rebuilt so allocation retries. Reader side does not lock and
+ * retries the allocation if zonelist changes. Writer side is protected by the
+ * embedded spin_lock.
+ */
+static DEFINE_SEQLOCK(zonelist_update_seq);
+
+static unsigned int zonelist_iter_begin(void)
+{
+	if (IS_ENABLED(CONFIG_MEMORY_HOTREMOVE))
+		return read_seqbegin(&zonelist_update_seq);
+
+	return 0;
+}
+
+static unsigned int check_retry_zonelist(unsigned int seq)
+{
+	if (IS_ENABLED(CONFIG_MEMORY_HOTREMOVE))
+		return read_seqretry(&zonelist_update_seq, seq);
+
+	return seq;
+}
+
 /* Perform direct synchronous page reclaim */
 static unsigned long
 __perform_reclaim(gfp_t gfp_mask, unsigned int order,
@@ -4625,6 +4653,7 @@
 	int compaction_retries;
 	int no_progress_loops;
 	unsigned int cpuset_mems_cookie;
+	unsigned int zonelist_iter_cookie;
 	int reserve_flags;
 
 	/*
@@ -4635,11 +4664,12 @@
 				(__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)))
 		gfp_mask &= ~__GFP_ATOMIC;
 
-retry_cpuset:
+restart:
 	compaction_retries = 0;
 	no_progress_loops = 0;
 	compact_priority = DEF_COMPACT_PRIORITY;
 	cpuset_mems_cookie = read_mems_allowed_begin();
+	zonelist_iter_cookie = zonelist_iter_begin();
 
 	/*
 	 * The fast path uses conservative alloc_flags to succeed only until
@@ -4798,9 +4828,13 @@
 		goto retry;
 
 
-	/* Deal with possible cpuset update races before we start OOM killing */
-	if (check_retry_cpuset(cpuset_mems_cookie, ac))
-		goto retry_cpuset;
+	/*
+	 * Deal with possible cpuset update races or zonelist updates to avoid
+	 * a unnecessary OOM kill.
+	 */
+	if (check_retry_cpuset(cpuset_mems_cookie, ac) ||
+	    check_retry_zonelist(zonelist_iter_cookie))
+		goto restart;
 
 	/* Reclaim has failed us, start killing things */
 	page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress);
@@ -4820,9 +4854,13 @@
 	}
 
 nopage:
-	/* Deal with possible cpuset update races before we fail */
-	if (check_retry_cpuset(cpuset_mems_cookie, ac))
-		goto retry_cpuset;
+	/*
+	 * Deal with possible cpuset update races or zonelist updates to avoid
+	 * a unnecessary OOM kill.
+	 */
+	if (check_retry_cpuset(cpuset_mems_cookie, ac) ||
+	    check_retry_zonelist(zonelist_iter_cookie))
+		goto restart;
 
 	/*
 	 * Make sure that __GFP_NOFAIL request doesn't leak out and make sure
@@ -5125,6 +5163,18 @@
 		/* reset page count bias and offset to start of new frag */
 		nc->pagecnt_bias = PAGE_FRAG_CACHE_MAX_SIZE + 1;
 		offset = size - fragsz;
+		if (unlikely(offset < 0)) {
+			/*
+			 * The caller is trying to allocate a fragment
+			 * with fragsz > PAGE_SIZE but the cache isn't big
+			 * enough to satisfy the request, this may
+			 * happen in low memory conditions.
+			 * We don't release the cache page because
+			 * it could make memory pressure worse
+			 * so we simply return NULL here.
+			 */
+			return NULL;
+		}
 	}
 
 	nc->pagecnt_bias--;
@@ -5653,7 +5703,7 @@
 	do {
 		zone_type--;
 		zone = pgdat->node_zones + zone_type;
-		if (managed_zone(zone)) {
+		if (populated_zone(zone)) {
 			zoneref_set_zone(zone, &zonerefs[nr_zones++]);
 			check_highest_zone(zone_type);
 		}
@@ -5920,9 +5970,8 @@
 	int nid;
 	int __maybe_unused cpu;
 	pg_data_t *self = data;
-	static DEFINE_SPINLOCK(lock);
 
-	spin_lock(&lock);
+	write_seqlock(&zonelist_update_seq);
 
 #ifdef CONFIG_NUMA
 	memset(node_load, 0, sizeof(node_load));
@@ -5955,7 +6004,7 @@
 #endif
 	}
 
-	spin_unlock(&lock);
+	write_sequnlock(&zonelist_update_seq);
 }
 
 static noinline void __init
@@ -7402,10 +7451,17 @@
 
 out2:
 	/* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
-	for (nid = 0; nid < MAX_NUMNODES; nid++)
+	for (nid = 0; nid < MAX_NUMNODES; nid++) {
+		unsigned long start_pfn, end_pfn;
+
 		zone_movable_pfn[nid] =
 			roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
 
+		get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
+		if (zone_movable_pfn[nid] >= end_pfn)
+			zone_movable_pfn[nid] = 0;
+	}
+
 out:
 	/* restore the node_state */
 	node_states[N_MEMORY] = saved_node_state;
@@ -7671,7 +7727,7 @@
 	 */
 #define adj_init_size(start, end, size, pos, adj) \
 	do { \
-		if (start <= pos && pos < end && size > adj) \
+		if (&start[0] <= &pos[0] && &pos[0] < &end[0] && size > adj) \
 			size -= adj; \
 	} while (0)