Linux mount operation

1, call: From the user state into the kernel state:

Syscall_define5 (Mount, Char __user *, Dev_name, Char __user *, Dir_name,char __user *, type, unsigned long, flags, void __ User *, data) {int Ret;char *kernel_type;struct filename *kernel_dir;char *kernel_dev;unsigned long data_page;        /* Copy data from user space to kernel space: type, mount path, parameters, etc. */ret = copy_mount_string (type, &kernel_type);  if (Ret < 0) goto Out_type;kernel_dir = GetName (Dir_name), if (Is_err (Kernel_dir)) {ret = Ptr_err (kernel_dir); Goto Out_d IR;} ret = copy_mount_string (Dev_name, &kernel_dev); if (Ret < 0) goto Out_dev;ret = copy_mount_options (data, &data_page); if (Ret < 0) goto Out_data;ret = Do_mount (Kernel_dev, Kernel_dir->name, Kernel_type, Flags, (void *) data_page); free_ Page (data_page); Out_data:kfree (Kernel_dev); Out_dev:putname (Kernel_dir); Out_dir:kfree (Kernel_type); Out_type: return ret;}

Note: struct filename *kernel_dir

struct filename {const char*name;/* pointer to actual string */const __user char*uptr;/* original userland pointer */struc T audit_names*aname;boolseparate; /* should "name" be freed? */};

　　

Linux mount operation