[PATCH 07/11] random: simplify accounting code slightly

[Greg Price <price@MIT.EDU>]

This commit makes the very boring simplifications so that the next
commit, which is a little trickier, is isolated and easy to review.
No change in behavior here at all.

Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Price <price@mit.edu>
---
 drivers/char/random.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/char/random.c b/drivers/char/random.c
index 8ec4a9a..8824e8d 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -858,18 +858,16 @@ static size_t account(struct entropy_store *r, size_t nbytes, int min,
 retry:
 		entropy_count = orig = ACCESS_ONCE(r->entropy_count);
 		/* If limited, never pull more than available */
-		if (r->limit && nbytes + reserved >= entropy_count / 8)
-			nbytes = entropy_count/8 - reserved;
+		if (r->limit)
+			nbytes = min_t(size_t, nbytes, entropy_count/8 - reserved);
 
 		if (entropy_count / 8 >= nbytes + reserved) {
 			entropy_count -= nbytes*8;
-			if (cmpxchg(&r->entropy_count, orig, entropy_count) != orig)
-				goto retry;
 		} else {
 			entropy_count = reserved;
-			if (cmpxchg(&r->entropy_count, orig, entropy_count) != orig)
-				goto retry;
 		}
+		if (cmpxchg(&r->entropy_count, orig, entropy_count) != orig)
+			goto retry;
 
 		if (entropy_count < random_write_wakeup_thresh)
 			wakeup_write = 1;
-- 
1.8.3.2