[dm-devel] [PATCH] Return EROFS if read-only detected on block device

[Milan Broz <mbroz redhat com>]

This allows userspace to distinguish what is going on.

EACCES is returned when user lacks required capability,
not that device is read-only.

Signed-off-by: Milan Broz <mbroz redhat com>
---
 fs/block_dev.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/fs/block_dev.c b/fs/block_dev.c
index c9cf9f7..db2c8db 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1219,7 +1219,7 @@ int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder)
 	/* __blkdev_get() may alter read only status, check it afterwards */
 	if (!res && (mode & FMODE_WRITE) && bdev_read_only(bdev)) {
 		__blkdev_put(bdev, mode, 0);
-		res = -EACCES;
+		res = -EROFS;
 	}
 
 	if (whole) {