From 436ab6dfc07d6c1c7345fdea57aeed2e41a1d72f Mon Sep 17 00:00:00 2001
From: Gris Ge <fge@redhat.com>
Date: Tue, 25 Dec 2018 19:38:12 +0800
Subject: [PATCH] Replace getmntent with thread-safe libmount.

Signed-off-by: Gris Ge <fge@redhat.com>
---
 src/peripety/Cargo.toml      |  2 +-
 src/peripety/src/blk_info.rs | 56 ++++++++++++------------------------
 src/peripety/src/lib.rs      |  2 +-
 3 files changed, 21 insertions(+), 39 deletions(-)

diff --git a/src/peripety/Cargo.toml b/src/peripety/Cargo.toml
index 8694693..ae6ab4c 100644
--- a/src/peripety/Cargo.toml
+++ b/src/peripety/Cargo.toml
@@ -8,4 +8,4 @@ serde = "1.0"
 serde_json = "1.0"
 serde_derive = "1.0"
 regex = "0.2.10"
-libc = "0.2"
+libmount = ">=0.1.10"
diff --git a/src/peripety/src/blk_info.rs b/src/peripety/src/blk_info.rs
index 7f17a00..add54ed 100644
--- a/src/peripety/src/blk_info.rs
+++ b/src/peripety/src/blk_info.rs
@@ -3,14 +3,13 @@ use super::error::PeripetyError;
 use super::scsi;
 use super::sysfs::Sysfs;
 
-use libc;
 use regex::Regex;
 use serde_json;
-use std::ffi::CStr;
-use std::ffi::CString;
 use std::fmt;
 use std::fs;
+use std::io::Read;
 use std::path::Path;
+use libmount::mountinfo;
 
 #[derive(Clone, PartialEq, Debug, Serialize)]
 pub enum BlkType {
@@ -231,44 +230,27 @@ impl BlkInfo {
     }
 
     pub fn get_mount_point(blk_path: &str) -> Option<String> {
-        let mut ret = String::new();
-        let fd = unsafe {
-            libc::setmntent(
-                CStr::from_bytes_with_nul(b"/proc/mounts\0")
-                    .expect("BUG: get_mount_point()")
-                    // ^We never panic as it is null terminated.
-                    .as_ptr(),
-                CStr::from_bytes_with_nul(b"r\0")
-                    .expect("BUG")
-                    .as_ptr(),
-                // ^We never panic as it is null terminated.
-            )
-        };
-        if fd.is_null() {
-            return None;
-        }
-        let mut entry = unsafe { libc::getmntent(fd) };
-        while !entry.is_null() {
-            let table: libc::mntent = unsafe { *entry };
-            if let Ok(mnt_fsname) =
-                unsafe { CStr::from_ptr(table.mnt_fsname).to_str() }
-            {
-                if mnt_fsname == blk_path {
-                    if let Ok(s) = unsafe {
-                        CString::from_raw(table.mnt_dir).into_string()
-                    } {
-                        ret = s;
-                        break;
+        let mut fd = fs::File::open("/proc/self/mountinfo").unwrap();
+        let mut data = Vec::new();
+        fd.read_to_end(&mut data).unwrap();
+
+        for e in mountinfo::Parser::new(&data) {
+            if let Ok(m) = e {
+                // TODO(Gris Ge): we should use read_link() to compare blk_path
+                // and mount_source.
+                if let Some(mount_source) = m.mount_source.into_owned().to_str()
+                {
+                    if let Some(mount_point) =
+                        m.mount_point.into_owned().to_str()
+                    {
+                        if mount_source == blk_path {
+                            return Some(format!("{}", mount_point));
+                        }
                     }
                 }
-                entry = unsafe { libc::getmntent(fd) };
             }
         }
-        unsafe { libc::endmntent(fd) };
-        if ret.is_empty() {
-            return None;
-        }
-        Some(ret)
+        None
     }
 
     pub fn major_minor_to_blk_name(
diff --git a/src/peripety/src/lib.rs b/src/peripety/src/lib.rs
index ebd5412..8936656 100644
--- a/src/peripety/src/lib.rs
+++ b/src/peripety/src/lib.rs
@@ -29,7 +29,7 @@
 extern crate serde;
 #[macro_use]
 extern crate serde_derive;
-extern crate libc;
+extern crate libmount;
 extern crate regex;
 extern crate serde_json;
 
-- 
2.20.1