tree 083df106c7b09328450a074422b5ebcc2133f51c
parent 856b7841c05019860b55445b795ae6ef5eb5c54c
author Christian Brauner <christian.brauner@ubuntu.com> 1617972371 +0200
committer Christian Brauner <christian.brauner@ubuntu.com> 1618393980 +0200
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ecryptfs: extend ro check to private mount

So far ecryptfs only verified that the superblock wasn't read-only but
didn't check whether the mount was. This made sense when we did not use
a private mount because the read-only state could change at any point.

Now that we have a private mount and mount properties can't change
behind our back extend the read-only check to include the vfsmount.

The __mnt_is_readonly() helper will check both the mount and the
superblock.  Note that before we checked root->d_sb and now we check
mnt->mnt_sb but since we have a matching <vfsmount, dentry> pair here
this is only syntactical change, not a semantic one.

Overlayfs and cachefiles have been changed to check this as well.

Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Tyler Hicks <code@tyhicks.com>
Cc: ecryptfs@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>