Add tracking of access times

Add the atime field, which tracks the last access time. Only reads
update the atime.

**BREAKING CHANGE**: One less extent available per block, 4 more bytes
for node names.

Cargo.lock

@@ -97,7 +97,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "redoxfs"
-version = "0.3.7"
+version = "0.4.0"
 dependencies = [
  "fuse 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.62 (registry+https://github.com/rust-lang/crates.io-index)",

Cargo.toml

@@ -2,7 +2,7 @@
 name = "redoxfs"
 description = "The Redox Filesystem"
 repository = "https://gitlab.redox-os.org/redox-os/redoxfs"
-version = "0.3.7"
+version = "0.4.0"
 license-file = "LICENSE"
 readme = "README.md"
 authors = ["Jeremy Soller <jackpot51@gmail.com>"]

src/filesystem.rs

@@ -1,4 +1,5 @@
 use std::cmp::min;
+use std::time::{SystemTime, UNIX_EPOCH};
 
 use syscall::error::{Result, Error, EEXIST, EISDIR, EINVAL, ENOENT, ENOSPC, ENOTDIR, ENOTEMPTY};
 
@@ -428,6 +429,7 @@ impl<D: Disk> FileSystem<D> {
     }
 
     pub fn read_node(&mut self, block: u64, offset: u64, buf: &mut [u8]) -> Result<usize> {
+        let atime = SystemTime::now().duration_since(UNIX_EPOCH).unwrap();
         let block_offset = offset / BLOCK_SIZE;
         let mut byte_offset = (offset % BLOCK_SIZE) as usize;
 
@@ -483,6 +485,20 @@ impl<D: Disk> FileSystem<D> {
             assert_eq!(block, extent.block + (extent.length + BLOCK_SIZE - 1)/BLOCK_SIZE);
         }
 
+        if i > 0 {
+            let atime_nsec = atime.subsec_nanos();
+            let atime = atime.as_secs();
+            let mut node = self.node(block)?;
+            if atime > node.1.atime || (atime == node.1.atime && atime_nsec > node.1.atime_nsec) {
+                let is_old = atime - node.1.atime > 3600; // Last read was more than a day ago
+                node.1.atime = atime;
+                node.1.atime_nsec = atime_nsec;
+                if is_old {
+                    self.write_at(node.0, &node.1)?;
+                }
+            }
+        }
+
         Ok(i)
     }
 

src/lib.rs

@@ -1,5 +1,5 @@
-#![crate_name="redoxfs"]
-#![crate_type="lib"]
+#![crate_name = "redoxfs"]
+#![crate_type = "lib"]
 
 extern crate syscall;
 extern crate uuid;
@@ -8,7 +8,7 @@ use std::sync::atomic::AtomicUsize;
 
 pub const BLOCK_SIZE: u64 = 4096;
 pub const SIGNATURE: &'static [u8; 8] = b"RedoxFS\0";
-pub const VERSION: u64 = 3;
+pub const VERSION: u64 = 4;
 pub static IS_UMT: AtomicUsize = AtomicUsize::new(0);
 
 pub use self::archive::{archive, archive_at};

src/mount/fuse.rs

@@ -117,7 +117,7 @@ impl<D: Disk> Filesystem for Fuse<D> {
 
     fn setattr(&mut self, _req: &Request, block: u64, mode: Option<u32>,
                 uid: Option<u32>, gid: Option<u32>, size: Option<u64>,
-                _atime: Option<Timespec>, mtime: Option<Timespec>, _fh: Option<u64>,
+                atime: Option<Timespec>, mtime: Option<Timespec>, _fh: Option<u64>,
                 _crtime: Option<Timespec>, _chgtime: Option<Timespec>, _bkuptime: Option<Timespec>,
                 _flags: Option<u32>, reply: ReplyAttr) {
         if let Some(mode) = mode {
@@ -176,11 +176,20 @@ impl<D: Disk> Filesystem for Fuse<D> {
             }
         }
 
-        if let Some(mtime) = mtime {
+        let need_update = atime.is_some() || mtime.is_some();
+        if need_update {
             match self.fs.node(block) {
                 Ok(mut node) => {
-                    node.1.mtime = mtime.sec as u64;
-                    node.1.mtime_nsec = mtime.nsec as u32;
+                    if let Some(atime) = atime {
+                        node.1.atime = atime.sec as u64;
+                        node.1.atime_nsec = atime.nsec as u32;
+                    }
+
+                    if let Some(mtime) = mtime {
+                        node.1.mtime = mtime.sec as u64;
+                        node.1.mtime_nsec = mtime.nsec as u32;
+                    }
+
                     if let Err(err) = self.fs.write_at(node.0, &node.1) {
                         reply.error(err.errno as i32);
                         return;

src/mount/redox/resource.rs

@@ -165,6 +165,8 @@ impl<D: Disk> Resource<D> for DirResource {
             st_size: fs.node_len(self.block)?,
             st_mtime: node.1.mtime,
             st_mtime_nsec: node.1.mtime_nsec,
+            st_atime: node.1.atime,
+            st_atime_nsec: node.1.atime_nsec,
             st_ctime: node.1.ctime,
             st_ctime_nsec: node.1.ctime_nsec,
             ..Default::default()
@@ -426,6 +428,8 @@ impl<D: Disk> Resource<D> for FileResource {
             st_size: fs.node_len(self.block)?,
             st_mtime: node.1.mtime,
             st_mtime_nsec: node.1.mtime_nsec,
+            st_atime: node.1.atime,
+            st_atime_nsec: node.1.atime_nsec,
             st_ctime: node.1.ctime,
             st_ctime_nsec: node.1.ctime_nsec,
             ..Default::default()
@@ -455,17 +459,16 @@ impl<D: Disk> Resource<D> for FileResource {
         let mut node = fs.node(self.block)?;
 
         if node.1.uid == self.uid || self.uid == 0 {
-            if let Some(mtime) = times.get(1) {
+            if let &[atime, mtime] = times {
 
                 node.1.mtime = mtime.tv_sec as u64;
                 node.1.mtime_nsec = mtime.tv_nsec as u32;
+                node.1.atime = atime.tv_sec as u64;
+                node.1.atime_nsec = atime.tv_nsec as u32;
 
                 fs.write_at(node.0, &node.1)?;
-
-                Ok(0)
-            } else {
-                Ok(0)
             }
+            Ok(0)
         } else {
             Err(Error::new(EPERM))
         }

src/node.rs

@@ -14,10 +14,12 @@ pub struct Node {
     pub ctime_nsec: u32,
     pub mtime: u64,
     pub mtime_nsec: u32,
-    pub name: [u8; 222],
+    pub atime: u64,
+    pub atime_nsec: u32,
+    pub name: [u8; 226],
     pub parent: u64,
     pub next: u64,
-    pub extents: [Extent; (BLOCK_SIZE as usize - 272)/16],
+    pub extents: [Extent; (BLOCK_SIZE as usize - 288)/16],
 }
 
 impl Node {
@@ -40,15 +42,17 @@ impl Node {
             ctime_nsec: 0,
             mtime: 0,
             mtime_nsec: 0,
-            name: [0; 222],
+            atime: 0,
+            atime_nsec: 0,
+            name: [0; 226],
             parent: 0,
             next: 0,
-            extents: [Extent::default(); (BLOCK_SIZE as usize - 272)/16],
+            extents: [Extent::default(); (BLOCK_SIZE as usize - 288)/16],
         }
     }
 
     pub fn new(mode: u16, name: &str, parent: u64, ctime: u64, ctime_nsec: u32) -> syscall::Result<Node> {
-        let mut bytes = [0; 222];
+        let mut bytes = [0; 226];
         if name.len() > bytes.len() {
             return Err(syscall::Error::new(syscall::ENAMETOOLONG));
         }
@@ -64,10 +68,12 @@ impl Node {
             ctime_nsec: ctime_nsec,
             mtime: ctime,
             mtime_nsec: ctime_nsec,
+            atime: ctime,
+            atime_nsec: ctime_nsec,
             name: bytes,
             parent: parent,
             next: 0,
-            extents: [Extent::default(); (BLOCK_SIZE as usize - 272)/16],
+            extents: [Extent::default(); (BLOCK_SIZE as usize - 288)/16],
         })
     }
 
@@ -85,7 +91,7 @@ impl Node {
     }
 
     pub fn set_name(&mut self, name: &str) -> syscall::Result<()> {
-        let mut bytes = [0; 222];
+        let mut bytes = [0; 226];
         if name.len() > bytes.len() {
             return Err(syscall::Error::new(syscall::ENAMETOOLONG));
         }