| Message ID | 20171010033302.20854-5-cyrilbur@gmail.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Allow opal-async waiters to get interrupted | expand |
On Tue, 10 Oct 2017 14:32:56 +1100 Cyril Bur <cyrilbur@gmail.com> wrote: > 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(+) > > 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; > } >
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; }
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> --- drivers/mtd/devices/powernv_flash.c | 7 +++++++ 1 file changed, 7 insertions(+)