[v5,04/10] mtd: powernv_flash: Don't return -ERESTARTSYS on interrupted token acquisition

Message ID 20171103024146.17086-5-cyrilbur@gmail.com
State Not Applicable
Headers show
Series
  • Allow opal-async waiters to get interrupted
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Commit Message

Cyril Bur Nov. 3, 2017, 2:41 a.m.
Because the MTD core might split up a read() or write() from userspace
into several calls to the driver, we may fail to get a token but already
have done some work, best to return -EINTR back to userspace and have
them decide what to do.

Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
 drivers/mtd/devices/powernv_flash.c | 7 +++++++
 1 file changed, 7 insertions(+)

Patch

diff --git a/drivers/mtd/devices/powernv_flash.c b/drivers/mtd/devices/powernv_flash.c
index 4dd3b5d2feb2..3343d4f5c4f3 100644
--- a/drivers/mtd/devices/powernv_flash.c
+++ b/drivers/mtd/devices/powernv_flash.c
@@ -47,6 +47,11 @@  enum flash_op {
 	FLASH_OP_ERASE,
 };
 
+/*
+ * Don't return -ERESTARTSYS if we can't get a token, the MTD core
+ * might have split up the call from userspace and called into the
+ * driver more than once, we'll already have done some amount of work.
+ */
 static int powernv_flash_async_op(struct mtd_info *mtd, enum flash_op op,
 		loff_t offset, size_t len, size_t *retlen, u_char *buf)
 {
@@ -63,6 +68,8 @@  static int powernv_flash_async_op(struct mtd_info *mtd, enum flash_op op,
 	if (token < 0) {
 		if (token != -ERESTARTSYS)
 			dev_err(dev, "Failed to get an async token\n");
+		else
+			token = -EINTR;
 		return token;
 	}