Permit access times for files after FilesystemStore startup

nativelink-store/BUILD.bazel

@@ -79,6 +79,7 @@ rust_library(
         "@crates//:http",
         "@crates//:http-body",
         "@crates//:http-body-util",
+        "@crates//:humantime",
         "@crates//:hyper",
         "@crates//:hyper-rustls",
         "@crates//:hyper-util",
@@ -165,6 +166,7 @@ rust_test_suite(
         "@crates//:bytes",
         "@crates//:dirs",
         "@crates//:flate2",
+        "@crates//:fs-set-times",
         "@crates//:futures",
         "@crates//:hex",
         "@crates//:http",

nativelink-store/Cargo.toml

@@ -58,6 +58,7 @@ hex = { version = "0.4.3", default-features = false }
 http = { version = "1.3.1", default-features = false }
 http-body = { version = "1.0.1", default-features = false }
 http-body-util = { version = "0.1.3", default-features = false }
+humantime = { version = "2.3.0", default-features = false }
 hyper = { version = "1.6.0", default-features = false }
 hyper-rustls = { version = "0.27.5", default-features = false, features = [
   "http1",
@@ -137,6 +138,7 @@ aws-smithy-types = { version = "1.3.0", default-features = false, features = [
 ] }
 dirs = { version = "6.0.0", default-features = false }
 flate2 = { version = "1.1.9", default-features = false, features = ["zlib-rs"] }
+fs-set-times = { version = "0.20.3", default-features = false }
 futures = { version = "0.3.31", default-features = false, features = [
   "executor",
 ] }

nativelink-store/src/filesystem_store.rs

@@ -15,6 +15,7 @@
 use core::fmt::{Debug, Formatter};
 use core::pin::Pin;
 use core::sync::atomic::{AtomicU64, Ordering};
+use core::time::Duration;
 use std::borrow::Cow;
 use std::ffi::{OsStr, OsString};
 use std::sync::{Arc, Weak};
@@ -26,7 +27,7 @@ use bytes::{Bytes, BytesMut};
 use futures::stream::{StreamExt, TryStreamExt};
 use futures::{Future, TryFutureExt};
 use nativelink_config::stores::FilesystemSpec;
-use nativelink_error::{Code, Error, ResultExt, make_err, make_input_err};
+use nativelink_error::{Code, Error, ResultExt, make_err};
 use nativelink_metric::MetricsComponent;
 use nativelink_util::background_spawn;
 use nativelink_util::buf_channel::{
@@ -452,9 +453,17 @@ async fn add_files_to_cache<Fe: FileEntry>(
                 key: key.borrow().into_owned(),
             }),
         );
-        let time_since_anchor = anchor_time
-            .duration_since(atime)
-            .map_err(|_| make_input_err!("File access time newer than now"))?;
+        let time_since_anchor = if let Ok(d) = anchor_time.duration_since(atime) {
+            d
+        } else {
+            warn!(
+                %file_name,
+                atime = %humantime::format_rfc3339(atime),
+                anchor_time = %humantime::format_rfc3339(*anchor_time),
+                "File access time newer than FilesystemStore start time",
+            );
+            Duration::ZERO
+        };
         evicting_map
             .insert_with_time(
                 key.into_owned().into(),

nativelink-store/tests/filesystem_store_test.rs

@@ -20,6 +20,7 @@ use std::env;
 use std::ffi::{OsStr, OsString};
 use std::path::Path;
 use std::sync::{Arc, LazyLock};
+use std::time::SystemTime;
 
 use async_lock::RwLock;
 use bytes::Bytes;
@@ -49,7 +50,7 @@ use tokio::sync::{Barrier, Semaphore};
 use tokio::time::sleep;
 use tokio_stream::StreamExt;
 use tokio_stream::wrappers::ReadDirStream;
-use tracing::Instrument;
+use tracing::{Instrument, debug};
 
 const VALID_HASH: &str = "0123456789abcdef000000000000000000010000000000000123456789abcdef";
 
@@ -1465,3 +1466,40 @@ async fn safe_small_safe_eviction() -> Result<(), Error> {
 
     Ok(())
 }
+
+#[nativelink_test]
+async fn add_too_early_files() -> Result<(), Error> {
+    let content_path = make_temp_path("content_path");
+    let temp_path = make_temp_path("temp_path");
+
+    let demo_file_folder = format!("{content_path}/s");
+    fs::create_dir_all(&demo_file_folder).await?;
+    let demo_file_path = format!("{demo_file_folder}/foo");
+    std::fs::write(&demo_file_path, "demo text")
+        .err_tip(|| format!("writing to {demo_file_path}"))?;
+    debug!(%demo_file_path, "demo file path");
+
+    // Add 60 seconds to the access time to trigger the logging message about access times
+    fs_set_times::set_atime(
+        &demo_file_path,
+        SystemTime::now()
+            .checked_add(Duration::from_secs(60))
+            .unwrap()
+            .into(),
+    )?;
+
+    FilesystemStore::<FileEntryImpl>::new(&FilesystemSpec {
+        content_path: content_path.clone(),
+        temp_path: temp_path.clone(),
+        read_buffer_size: 1,
+        ..Default::default()
+    })
+    .await
+    .err_tip(|| "during FileSystemStore::new")?;
+
+    assert!(logs_contain(
+        "File access time newer than FilesystemStore start time file_name=foo atime=20"
+    ));
+
+    Ok(())
+}