Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

[linux-drm-fsl-dcu.git] / drivers / md / dm-crypt.c

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index d60c88df5234a0099292712cc1117dc1e65b78e0..4b3b6f8aff0cb4112a7bafa2c128027f804468b6 100644 (file)
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -968,7 +968,8 @@ static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone);
 
 /*
  * Generate a new unfragmented bio with the given size
- * This should never violate the device limitations
+ * This should never violate the device limitations (but only because
+ * max_segment_size is being constrained to PAGE_SIZE).
  *
  * This function may be called concurrently. If we allocate from the mempool
  * concurrently, there is a possibility of deadlock. For example, if we have
@@ -2045,9 +2046,20 @@ static int crypt_iterate_devices(struct dm_target *ti,
        return fn(ti, cc->dev, cc->start, ti->len, data);
 }
 
+static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits)
+{
+       /*
+        * Unfortunate constraint that is required to avoid the potential
+        * for exceeding underlying device's max_segments limits -- due to
+        * crypt_alloc_buffer() possibly allocating pages for the encryption
+        * bio that are not as physically contiguous as the original bio.
+        */
+       limits->max_segment_size = PAGE_SIZE;
+}
+
 static struct target_type crypt_target = {
        .name   = "crypt",
-       .version = {1, 14, 0},
+       .version = {1, 14, 1},
        .module = THIS_MODULE,
        .ctr    = crypt_ctr,
        .dtr    = crypt_dtr,
@@ -2058,6 +2070,7 @@ static struct target_type crypt_target = {
        .resume = crypt_resume,
        .message = crypt_message,
        .iterate_devices = crypt_iterate_devices,
+       .io_hints = crypt_io_hints,
 };
 
 static int __init dm_crypt_init(void)