dm-writecache: allow allocations larger than 2GiB

Commit Message

Mikulas Patocka Jan. 9, 2024, 3 p.m. UTC

The function kvmalloc_node limits the allocation size to INT_MAX. This
limit will be overflowed if dm-writecache attempts to map a device with
1TiB or larger length. This commit changes kvmalloc_array to vmalloc_array
to avoid the limit.

The commit also changes vmalloc(array_size()) to vmalloc_array().

Signed-off-by: Mikulas Patocka <[e-mail]>

---
 drivers/md/dm-writecache.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

Patch

Index: linux-2.6/drivers/md/dm-writecache.c
===================================================================
--- linux-2.6.orig/drivers/md/dm-writecache.c	2023-09-05 14:45:58.000000000 +0200
+++ linux-2.6/drivers/md/dm-writecache.c	2024-01-08 22:22:22.000000000 +0100
@@ -299,7 +299,7 @@  static int persistent_memory_claim(struc
 		long i;
 
 		wc->memory_map = NULL;
-		pages = kvmalloc_array(p, sizeof(struct page *), GFP_KERNEL);
+		pages = vmalloc_array(p, sizeof(struct page *));
 		if (!pages) {
 			r = -ENOMEM;
 			goto err2;
@@ -330,7 +330,7 @@  static int persistent_memory_claim(struc
 			r = -ENOMEM;
 			goto err3;
 		}
-		kvfree(pages);
+		vfree(pages);
 		wc->memory_vmapped = true;
 	}
 
@@ -341,7 +341,7 @@  static int persistent_memory_claim(struc
 
 	return 0;
 err3:
-	kvfree(pages);
+	vfree(pages);
 err2:
 	dax_read_unlock(id);
 err1:
@@ -962,7 +962,7 @@  static int writecache_alloc_entries(stru
 
 	if (wc->entries)
 		return 0;
-	wc->entries = vmalloc(array_size(sizeof(struct wc_entry), wc->n_blocks));
+	wc->entries = vmalloc_array(wc->n_blocks, sizeof(struct wc_entry));
 	if (!wc->entries)
 		return -ENOMEM;
 	for (b = 0; b < wc->n_blocks; b++) {