Merging upstream version 6.9.7.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 35 insertions, 19 deletions

diff --git a/mm/swapfile.c b/mm/swapfile.c
index 6fe0cc2553..4919423cce 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -737,8 +737,6 @@ static void swap_range_free(struct swap_info_struct *si, unsigned long offset,
 		if (was_full && (si->flags & SWP_WRITEOK))
 			add_to_avail_list(si);
 	}
-	atomic_long_add(nr_entries, &nr_swap_pages);
-	WRITE_ONCE(si->inuse_pages, si->inuse_pages - nr_entries);
 	if (si->flags & SWP_BLKDEV)
 		swap_slot_free_notify =
 			si->bdev->bd_disk->fops->swap_slot_free_notify;
@@ -746,12 +744,19 @@ static void swap_range_free(struct swap_info_struct *si, unsigned long offset,
 		swap_slot_free_notify = NULL;
 	while (offset <= end) {
 		arch_swap_invalidate_page(si->type, offset);
-		zswap_invalidate(si->type, offset);
 		if (swap_slot_free_notify)
 			swap_slot_free_notify(si->bdev, offset);
 		offset++;
 	}
 	clear_shadow_from_swap_cache(si->type, begin, end);
+
+	/*
+	 * Make sure that try_to_unuse() observes si->inuse_pages reaching 0
+	 * only after the above cleanups are done.
+	 */
+	smp_wmb();
+	atomic_long_add(nr_entries, &nr_swap_pages);
+	WRITE_ONCE(si->inuse_pages, si->inuse_pages - nr_entries);
 }
 
 static void set_cluster_next(struct swap_info_struct *si, unsigned long next)
@@ -2060,7 +2065,7 @@ static int try_to_unuse(unsigned int type)
 	unsigned int i;
 
 	if (!READ_ONCE(si->inuse_pages))
-		return 0;
+		goto success;
 
 retry:
 	retval = shmem_unuse(type);
@@ -2141,6 +2146,12 @@ retry:
 		return -EINTR;
 	}
 
+success:
+	/*
+	 * Make sure that further cleanups after try_to_unuse() returns happen
+	 * after swap_range_free() reduces si->inuse_pages to 0.
+	 */
+	smp_mb();
 	return 0;
 }
 
@@ -2359,8 +2370,6 @@ static void enable_swap_info(struct swap_info_struct *p, int prio,
 				unsigned char *swap_map,
 				struct swap_cluster_info *cluster_info)
 {
-	zswap_swapon(p->type);
-
 	spin_lock(&swap_lock);
 	spin_lock(&p->lock);
 	setup_swap_info(p, prio, swap_map, cluster_info);
@@ -2543,10 +2552,10 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
 	exit_swap_address_space(p->type);
 
 	inode = mapping->host;
-	if (p->bdev_handle) {
+	if (p->bdev_file) {
 		set_blocksize(p->bdev, old_block_size);
-		bdev_release(p->bdev_handle);
-		p->bdev_handle = NULL;
+		fput(p->bdev_file);
+		p->bdev_file = NULL;
 	}
 
 	inode_lock(inode);
@@ -2776,14 +2785,14 @@ static int claim_swapfile(struct swap_info_struct *p, struct inode *inode)
 	int error;
 
 	if (S_ISBLK(inode->i_mode)) {
-		p->bdev_handle = bdev_open_by_dev(inode->i_rdev,
+		p->bdev_file = bdev_file_open_by_dev(inode->i_rdev,
 				BLK_OPEN_READ | BLK_OPEN_WRITE, p, NULL);
-		if (IS_ERR(p->bdev_handle)) {
-			error = PTR_ERR(p->bdev_handle);
-			p->bdev_handle = NULL;
+		if (IS_ERR(p->bdev_file)) {
+			error = PTR_ERR(p->bdev_file);
+			p->bdev_file = NULL;
 			return error;
 		}
-		p->bdev = p->bdev_handle->bdev;
+		p->bdev = file_bdev(p->bdev_file);
 		p->old_block_size = block_size(p->bdev);
 		error = set_blocksize(p->bdev, PAGE_SIZE);
 		if (error < 0)
@@ -3178,6 +3187,10 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
 	if (error)
 		goto bad_swap_unlock_inode;
 
+	error = zswap_swapon(p->type, maxpages);
+	if (error)
+		goto free_swap_address_space;
+
 	/*
 	 * Flush any pending IO and dirty mappings before we start using this
 	 * swap device.
@@ -3186,7 +3199,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
 	error = inode_drain_writes(inode);
 	if (error) {
 		inode->i_flags &= ~S_SWAPFILE;
-		goto free_swap_address_space;
+		goto free_swap_zswap;
 	}
 
 	mutex_lock(&swapon_mutex);
@@ -3210,6 +3223,8 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
 
 	error = 0;
 	goto out;
+free_swap_zswap:
+	zswap_swapoff(p->type);
 free_swap_address_space:
 	exit_swap_address_space(p->type);
 bad_swap_unlock_inode:
@@ -3219,10 +3234,10 @@ bad_swap:
 	p->percpu_cluster = NULL;
 	free_percpu(p->cluster_next_cpu);
 	p->cluster_next_cpu = NULL;
-	if (p->bdev_handle) {
+	if (p->bdev_file) {
 		set_blocksize(p->bdev, p->old_block_size);
-		bdev_release(p->bdev_handle);
-		p->bdev_handle = NULL;
+		fput(p->bdev_file);
+		p->bdev_file = NULL;
 	}
 	inode = NULL;
 	destroy_swap_extents(p);
@@ -3331,7 +3346,8 @@ static int __swap_duplicate(swp_entry_t entry, unsigned char usage)
 	} else
 		err = -ENOENT;			/* unused swap entry */
 
-	WRITE_ONCE(p->swap_map[offset], count | has_cache);
+	if (!err)
+		WRITE_ONCE(p->swap_map[offset], count | has_cache);
 
 unlock_out:
 	unlock_cluster_or_swap_info(p, ci);