generic_permission (9) Linux Manual Page
generic_permission – check for access rights on a Posix-like filesystem
Synopsis
int generic_permission(struct inode *inode, int mask);Arguments
inode
-
- inode to check access rights for
mask
- right to check for (
MAY_READ,MAY_WRITE,MAY_EXEC, …)
Description
Used to check for read/write/execute permissions on a file. We use “fsuid” for this, letting us set arbitrary permissions for filesystem access without changing the “normal” uids which are used for other things.
generic_permission is rcu-walk aware. It returns -ECHILD in case an rcu-walk request cannot be satisfied (eg. requires blocking or too much complexity). It would then be called again in ref-walk mode.