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Diffstat (limited to 'block/ioctl.c')
-rw-r--r--block/ioctl.c28
1 files changed, 23 insertions, 5 deletions
diff --git a/block/ioctl.c b/block/ioctl.c
index 337d207ab14d..ba15b2dbfb98 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -5,7 +5,7 @@
#include <linux/blkpg.h>
#include <linux/hdreg.h>
#include <linux/backing-dev.h>
-#include <linux/buffer_head.h>
+#include <linux/fs.h>
#include <linux/blktrace_api.h>
#include <asm/uaccess.h>
@@ -180,6 +180,26 @@ int __blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode,
EXPORT_SYMBOL_GPL(__blkdev_driver_ioctl);
/*
+ * Is it an unrecognized ioctl? The correct returns are either
+ * ENOTTY (final) or ENOIOCTLCMD ("I don't know this one, try a
+ * fallback"). ENOIOCTLCMD gets turned into ENOTTY by the ioctl
+ * code before returning.
+ *
+ * Confused drivers sometimes return EINVAL, which is wrong. It
+ * means "I understood the ioctl command, but the parameters to
+ * it were wrong".
+ *
+ * We should aim to just fix the broken drivers, the EINVAL case
+ * should go away.
+ */
+static inline int is_unrecognized_ioctl(int ret)
+{
+ return ret == -EINVAL ||
+ ret == -ENOTTY ||
+ ret == -ENOIOCTLCMD;
+}
+
+/*
* always keep this in sync with compat_blkdev_ioctl()
*/
int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
@@ -196,8 +216,7 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
return -EACCES;
ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
- /* -EINVAL to handle old uncorrected drivers */
- if (ret != -EINVAL && ret != -ENOTTY)
+ if (!is_unrecognized_ioctl(ret))
return ret;
fsync_bdev(bdev);
@@ -206,8 +225,7 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
case BLKROSET:
ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
- /* -EINVAL to handle old uncorrected drivers */
- if (ret != -EINVAL && ret != -ENOTTY)
+ if (!is_unrecognized_ioctl(ret))
return ret;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;