Loading Documentation/filesystems/porting +17 −0 Original line number Original line Diff line number Diff line Loading @@ -483,3 +483,20 @@ in your dentry operations instead. -- -- [mandatory] [mandatory] ->aio_read/->aio_write are gone. Use ->read_iter/->write_iter. ->aio_read/->aio_write are gone. Use ->read_iter/->write_iter. --- [recommended] for embedded ("fast") symlinks just set inode->i_link to wherever the symlink body is and use simple_follow_link() as ->follow_link(). -- [mandatory] calling conventions for ->follow_link() have changed. Instead of returning cookie and using nd_set_link() to store the body to traverse, we return the body to traverse and store the cookie using explicit void ** argument. nameidata isn't passed at all - nd_jump_link() doesn't need it and nd_[gs]et_link() is gone. -- [mandatory] calling conventions for ->put_link() have changed. It gets inode instead of dentry, it does not get nameidata at all and it gets called only when cookie is non-NULL. Note that link body isn't available anymore, so if you need it, store it as cookie. Documentation/filesystems/vfs.txt +10 −8 Original line number Original line Diff line number Diff line Loading @@ -436,16 +436,18 @@ otherwise noted. follow_link: called by the VFS to follow a symbolic link to the follow_link: called by the VFS to follow a symbolic link to the inode it points to. Only required if you want to support inode it points to. Only required if you want to support symbolic links. This method returns a void pointer cookie symbolic links. This method returns the symlink body that is passed to put_link(). to traverse (and possibly resets the current position with nd_jump_link()). If the body won't go away until the inode is gone, nothing else is needed; if it needs to be otherwise pinned, the data needed to release whatever we'd grabbed is to be stored in void * variable passed by address to follow_link() instance. put_link: called by the VFS to release resources allocated by put_link: called by the VFS to release resources allocated by follow_link(). The cookie returned by follow_link() is passed follow_link(). The cookie stored by follow_link() is passed to this method as the last parameter. It is used by to this method as the last parameter; only called when filesystems such as NFS where page cache is not stable cookie isn't NULL. (i.e. page that was installed when the symbolic link walk started might not be in the page cache at the end of the walk). permission: called by the VFS to check for access rights on a POSIX-like permission: called by the VFS to check for access rights on a POSIX-like filesystem. filesystem. Loading Loading
Documentation/filesystems/porting +17 −0 Original line number Original line Diff line number Diff line Loading @@ -483,3 +483,20 @@ in your dentry operations instead. -- -- [mandatory] [mandatory] ->aio_read/->aio_write are gone. Use ->read_iter/->write_iter. ->aio_read/->aio_write are gone. Use ->read_iter/->write_iter. --- [recommended] for embedded ("fast") symlinks just set inode->i_link to wherever the symlink body is and use simple_follow_link() as ->follow_link(). -- [mandatory] calling conventions for ->follow_link() have changed. Instead of returning cookie and using nd_set_link() to store the body to traverse, we return the body to traverse and store the cookie using explicit void ** argument. nameidata isn't passed at all - nd_jump_link() doesn't need it and nd_[gs]et_link() is gone. -- [mandatory] calling conventions for ->put_link() have changed. It gets inode instead of dentry, it does not get nameidata at all and it gets called only when cookie is non-NULL. Note that link body isn't available anymore, so if you need it, store it as cookie.
Documentation/filesystems/vfs.txt +10 −8 Original line number Original line Diff line number Diff line Loading @@ -436,16 +436,18 @@ otherwise noted. follow_link: called by the VFS to follow a symbolic link to the follow_link: called by the VFS to follow a symbolic link to the inode it points to. Only required if you want to support inode it points to. Only required if you want to support symbolic links. This method returns a void pointer cookie symbolic links. This method returns the symlink body that is passed to put_link(). to traverse (and possibly resets the current position with nd_jump_link()). If the body won't go away until the inode is gone, nothing else is needed; if it needs to be otherwise pinned, the data needed to release whatever we'd grabbed is to be stored in void * variable passed by address to follow_link() instance. put_link: called by the VFS to release resources allocated by put_link: called by the VFS to release resources allocated by follow_link(). The cookie returned by follow_link() is passed follow_link(). The cookie stored by follow_link() is passed to this method as the last parameter. It is used by to this method as the last parameter; only called when filesystems such as NFS where page cache is not stable cookie isn't NULL. (i.e. page that was installed when the symbolic link walk started might not be in the page cache at the end of the walk). permission: called by the VFS to check for access rights on a POSIX-like permission: called by the VFS to check for access rights on a POSIX-like filesystem. filesystem. Loading
Al Viro <viro@zeniv.linux.org.uk>Al Viro <viro@zeniv.linux.org.uk>