Update Linux to v5.4.148

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz

Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/mm/swapfile.c b/mm/swapfile.c
index dab4352..f696421 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -221,6 +221,19 @@
 	BUG();
 }
 
+sector_t swap_page_sector(struct page *page)
+{
+	struct swap_info_struct *sis = page_swap_info(page);
+	struct swap_extent *se;
+	sector_t sector;
+	pgoff_t offset;
+
+	offset = __page_file_index(page);
+	se = offset_to_swap_extent(sis, offset);
+	sector = se->start_block + (offset - se->start_page);
+	return sector << (PAGE_SHIFT - 9);
+}
+
 /*
  * swap allocation tell device that a cluster of swap can now be discarded,
  * to allow the swap device to optimize its wear-levelling.
@@ -1038,7 +1051,7 @@
 			goto nextsi;
 		}
 		if (size == SWAPFILE_CLUSTER) {
-			if (!(si->flags & SWP_FS))
+			if (si->flags & SWP_BLKDEV)
 				n_ret = swap_alloc_cluster(si, swp_entries);
 		} else
 			n_ret = scan_swap_map_slots(si, SWAP_HAS_CACHE,
@@ -2132,7 +2145,7 @@
 	swp_entry_t entry;
 	unsigned int i;
 
-	if (!si->inuse_pages)
+	if (!READ_ONCE(si->inuse_pages))
 		return 0;
 
 	if (!frontswap)
@@ -2148,7 +2161,7 @@
 
 	spin_lock(&mmlist_lock);
 	p = &init_mm.mmlist;
-	while (si->inuse_pages &&
+	while (READ_ONCE(si->inuse_pages) &&
 	       !signal_pending(current) &&
 	       (p = p->next) != &init_mm.mmlist) {
 
@@ -2177,7 +2190,7 @@
 	mmput(prev_mm);
 
 	i = 0;
-	while (si->inuse_pages &&
+	while (READ_ONCE(si->inuse_pages) &&
 	       !signal_pending(current) &&
 	       (i = find_next_to_unuse(si, i, frontswap)) != 0) {
 
@@ -2219,7 +2232,7 @@
 	 * been preempted after get_swap_page(), temporarily hiding that swap.
 	 * It's easy and robust (though cpu-intensive) just to keep retrying.
 	 */
-	if (si->inuse_pages) {
+	if (READ_ONCE(si->inuse_pages)) {
 		if (!signal_pending(current))
 			goto retry;
 		retval = -EINTR;
@@ -2737,10 +2750,10 @@
 	else
 		type = si->type + 1;
 
+	++(*pos);
 	for (; (si = swap_type_to_swap_info(type)); type++) {
 		if (!(si->flags & SWP_USED) || !si->swap_map)
 			continue;
-		++*pos;
 		return si;
 	}
 
@@ -2824,6 +2837,7 @@
 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;
 
@@ -2852,7 +2866,7 @@
 		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()
@@ -2865,6 +2879,7 @@
 		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);
 
@@ -2892,10 +2907,6 @@
 		p->bdev = inode->i_sb->s_bdev;
 	}
 
-	inode_lock(inode);
-	if (IS_SWAPFILE(inode))
-		return -EBUSY;
-
 	return 0;
 }
 
@@ -3150,17 +3161,22 @@
 	mapping = swap_file->f_mapping;
 	inode = mapping->host;
 
-	/* If S_ISREG(inode->i_mode) will do inode_lock(inode); */
 	error = claim_swapfile(p, inode);
 	if (unlikely(error))
 		goto bad_swap;
 
+	inode_lock(inode);
+	if (IS_SWAPFILE(inode)) {
+		error = -EBUSY;
+		goto bad_swap_unlock_inode;
+	}
+
 	/*
 	 * Read the swap header.
 	 */
 	if (!mapping->a_ops->readpage) {
 		error = -EINVAL;
-		goto bad_swap;
+		goto bad_swap_unlock_inode;
 	}
 	page = read_mapping_page(mapping, 0, swap_file);
 	if (IS_ERR(page)) {
@@ -3172,14 +3188,14 @@
 	maxpages = read_swap_header(p, swap_header, inode);
 	if (unlikely(!maxpages)) {
 		error = -EINVAL;
-		goto bad_swap;
+		goto bad_swap_unlock_inode;
 	}
 
 	/* OK, set up the swap map and apply the bad block list */
 	swap_map = vzalloc(maxpages);
 	if (!swap_map) {
 		error = -ENOMEM;
-		goto bad_swap;
+		goto bad_swap_unlock_inode;
 	}
 
 	if (bdi_cap_stable_pages_required(inode_to_bdi(inode)))
@@ -3204,7 +3220,7 @@
 					GFP_KERNEL);
 		if (!cluster_info) {
 			error = -ENOMEM;
-			goto bad_swap;
+			goto bad_swap_unlock_inode;
 		}
 
 		for (ci = 0; ci < nr_cluster; ci++)
@@ -3213,7 +3229,7 @@
 		p->percpu_cluster = alloc_percpu(struct percpu_cluster);
 		if (!p->percpu_cluster) {
 			error = -ENOMEM;
-			goto bad_swap;
+			goto bad_swap_unlock_inode;
 		}
 		for_each_possible_cpu(cpu) {
 			struct percpu_cluster *cluster;
@@ -3227,13 +3243,13 @@
 
 	error = swap_cgroup_swapon(p->type, maxpages);
 	if (error)
-		goto bad_swap;
+		goto bad_swap_unlock_inode;
 
 	nr_extents = setup_swap_map_and_extents(p, swap_header, swap_map,
 		cluster_info, maxpages, &span);
 	if (unlikely(nr_extents < 0)) {
 		error = nr_extents;
-		goto bad_swap;
+		goto bad_swap_unlock_inode;
 	}
 	/* frontswap enabled? set up bit-per-page map for frontswap */
 	if (IS_ENABLED(CONFIG_FRONTSWAP))
@@ -3273,7 +3289,7 @@
 
 	error = init_swap_address_space(p->type, maxpages);
 	if (error)
-		goto bad_swap;
+		goto bad_swap_unlock_inode;
 
 	/*
 	 * Flush any pending IO and dirty mappings before we start using this
@@ -3283,7 +3299,7 @@
 	error = inode_drain_writes(inode);
 	if (error) {
 		inode->i_flags &= ~S_SWAPFILE;
-		goto bad_swap;
+		goto free_swap_address_space;
 	}
 
 	mutex_lock(&swapon_mutex);
@@ -3308,6 +3324,10 @@
 
 	error = 0;
 	goto out;
+free_swap_address_space:
+	exit_swap_address_space(p->type);
+bad_swap_unlock_inode:
+	inode_unlock(inode);
 bad_swap:
 	free_percpu(p->percpu_cluster);
 	p->percpu_cluster = NULL;
@@ -3315,6 +3335,7 @@
 		set_blocksize(p->bdev, p->old_block_size);
 		blkdev_put(p->bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL);
 	}
+	inode = NULL;
 	destroy_swap_extents(p);
 	swap_cgroup_swapoff(p->type);
 	spin_lock(&swap_lock);
@@ -3326,13 +3347,8 @@
 	kvfree(frontswap_map);
 	if (inced_nr_rotate_swap)
 		atomic_dec(&nr_rotate_swap);
-	if (swap_file) {
-		if (inode) {
-			inode_unlock(inode);
-			inode = NULL;
-		}
+	if (swap_file)
 		filp_close(swap_file, NULL);
-	}
 out:
 	if (page && !IS_ERR(page)) {
 		kunmap(page);