diff mbox series

[4/4] dm-crypt: sleep and retry on allocation errors

Message ID 20200601160421.912555280@debian-a64.vm
State New
Headers show
Series None | expand

Commit Message

Mikulas Patocka June 1, 2020, 4:03 p.m. UTC 
Some hardware crypto drivers use GFP_ATOMIC allocations in the request
routine. These allocations can randomly fail - for example, they fail if
too many network packets are received.

If we propagated the failure up to the I/O stack, it would cause I/O
errors and data corruption. So, we sleep and retry.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
diff mbox series

Patch

Index: linux-2.6/drivers/md/dm-crypt.c
===================================================================
--- linux-2.6.orig/drivers/md/dm-crypt.c
+++ linux-2.6/drivers/md/dm-crypt.c
@@ -1534,6 +1534,7 @@  static blk_status_t crypt_convert(struct
 		crypt_alloc_req(cc, ctx);
 		atomic_inc(&ctx->cc_pending);
 
+again:
 		if (crypt_integrity_aead(cc))
 			r = crypt_convert_block_aead(cc, ctx, ctx->r.req_aead, tag_offset);
 		else
@@ -1541,6 +1542,17 @@  static blk_status_t crypt_convert(struct
 
 		switch (r) {
 		/*
+		 * Some hardware crypto drivers use GFP_ATOMIC allocations in
+		 * the request routine. These allocations can randomly fail. If
+		 * we propagated the failure up to the I/O stack, it would cause
+		 * I/O errors and data corruption.
+		 *
+		 * So, we sleep and retry.
+		 */
+		case -ENOMEM:
+			msleep(1);
+			goto again;
+		/*
 		 * The request was queued by a crypto driver
 		 * but the driver request queue is full, let's wait.
 		 */