From e51900f7d38cbcfb481d84567fd92540e7e1d23a Mon Sep 17 00:00:00 2001 From: Chuck Ebbert Date: Wed, 16 Feb 2011 18:11:53 -0500 Subject: [PATCH] block: revert block_dev read-only check This reverts commit 75f1dc0d076d ("block: check bdev_read_only() from blkdev_get()"). That commit added stricter checking to make sure devices that were being used read-only were actually opened in that mode. It turns out that the change breaks a bunch of kernel code that opens block devices. Affected systems include dm, md, and the loop device. Because strict checking for read-only opens of block devices was not done before this, the code that opens the devices was opening them read-write even if they were being used read-only. Auditing all that code will take time, and new userspace packages for dm, mdadm, etc. will also be required. Signed-off-by: Chuck Ebbert Signed-off-by: Linus Torvalds --- fs/block_dev.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/fs/block_dev.c b/fs/block_dev.c index 333a7bb4cb9c..4fb8a3431531 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1215,12 +1215,6 @@ int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder) res = __blkdev_get(bdev, mode, 0); - /* __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; - } - if (whole) { /* finish claiming */ mutex_lock(&bdev->bd_mutex); @@ -1298,6 +1292,11 @@ struct block_device *blkdev_get_by_path(const char *path, fmode_t mode, if (err) return ERR_PTR(err); + if ((mode & FMODE_WRITE) && bdev_read_only(bdev)) { + blkdev_put(bdev, mode); + return ERR_PTR(-EACCES); + } + return bdev; } EXPORT_SYMBOL(blkdev_get_by_path);