Rename internal CacheConfig field 'prefer_s3' to 'serve_lookup_from_c…

…ache'

Signed-off-by: Daniel Carl Jones <[email protected]>

mountpoint-s3/src/fs.rs

@@ -252,13 +252,14 @@ fn are_from_same_process(pid1: u32, pid2: u32) -> bool {
 
 #[derive(Debug, Clone)]
 pub struct CacheConfig {
-    /// Should the file system check S3 even when a valid cached entry may be available?
+    /// Should the file system serve lookup requests including open from cached entries,
+    /// or instead check S3 even when a valid cached entry may be available?
     ///
-    /// When enabled, some operations such as `getattr` are allowed to be served from cache
+    /// Even when disabled, some operations such as `getattr` are allowed to be served from cache
     /// with a short TTL since Linux filesystems behave badly when the TTL is zero.
-    /// For example, results from `readdir` will expire immediately, and so the kernel will
+    /// For example, results from `readdir` would expire immediately, and the kernel would
     /// immediately `getattr` every entry returned from `readdir`.
-    pub prefer_s3: bool,
+    pub serve_lookup_from_cache: bool,
     /// How long the kernel will cache metadata for files
     pub file_ttl: Duration,
     /// How long the kernel will cache metadata for directories
@@ -280,7 +281,7 @@ impl Default for CacheConfig {
         let dir_ttl = Duration::from_millis(1000);
 
         Self {
-            prefer_s3: true,
+            serve_lookup_from_cache: false,
             file_ttl,
             dir_ttl,
         }
@@ -531,7 +532,7 @@ where
     pub async fn open(&self, ino: InodeNo, flags: i32, pid: u32) -> Result<Opened, Error> {
         trace!("fs:open with ino {:?} flags {:?} pid {:?}", ino, flags, pid);
 
-        let force_revalidate = self.config.cache_config.prefer_s3;
+        let force_revalidate = !self.config.cache_config.serve_lookup_from_cache;
         let lookup = self.superblock.getattr(&self.client, ino, force_revalidate).await?;
 
         match lookup.inode.kind() {

mountpoint-s3/src/inode.rs

@@ -183,7 +183,12 @@ impl Superblock {
         trace!(parent=?parent_ino, ?name, "lookup");
         let lookup = self
             .inner
-            .lookup_by_name(client, parent_ino, name, self.inner.cache_config.prefer_s3)
+            .lookup_by_name(
+                client,
+                parent_ino,
+                name,
+                self.inner.cache_config.serve_lookup_from_cache,
+            )
             .await?;
         self.inner.remember(&lookup.inode);
         Ok(lookup)
@@ -303,7 +308,7 @@ impl Superblock {
 
         let existing = self
             .inner
-            .lookup_by_name(client, dir, name, self.inner.cache_config.prefer_s3)
+            .lookup_by_name(client, dir, name, self.inner.cache_config.serve_lookup_from_cache)
             .await;
         match existing {
             Ok(lookup) => return Err(InodeError::FileAlreadyExists(lookup.inode.err())),
@@ -360,7 +365,12 @@ impl Superblock {
     ) -> Result<(), InodeError> {
         let LookedUp { inode, .. } = self
             .inner
-            .lookup_by_name(client, parent_ino, name, self.inner.cache_config.prefer_s3)
+            .lookup_by_name(
+                client,
+                parent_ino,
+                name,
+                self.inner.cache_config.serve_lookup_from_cache,
+            )
             .await?;
 
         if inode.kind() == InodeKind::File {
@@ -429,7 +439,12 @@ impl Superblock {
         let parent = self.inner.get(parent_ino)?;
         let LookedUp { inode, .. } = self
             .inner
-            .lookup_by_name(client, parent_ino, name, self.inner.cache_config.prefer_s3)
+            .lookup_by_name(
+                client,
+                parent_ino,
+                name,
+                self.inner.cache_config.serve_lookup_from_cache,
+            )
             .await?;
 
         if inode.kind() == InodeKind::Directory {
@@ -534,7 +549,7 @@ impl SuperblockInner {
         client: &OC,
         parent_ino: InodeNo,
         name: &OsStr,
-        skip_cache: bool,
+        allow_cache: bool,
     ) -> Result<LookedUp, InodeError> {
         let name = name
             .to_str()
@@ -546,10 +561,10 @@ impl SuperblockInner {
             return Err(InodeError::InvalidFileName(name.into()));
         }
 
-        let lookup = if skip_cache {
-            None
-        } else {
+        let lookup = if allow_cache {
             self.cache_lookup(parent_ino, name)
+        } else {
+            None
         };
 
         let lookup = match lookup {
@@ -1635,7 +1650,7 @@ mod tests {
             bucket,
             &prefix,
             CacheConfig {
-                prefer_s3: false,
+                serve_lookup_from_cache: true,
                 dir_ttl: ttl,
                 file_ttl: ttl,
             },

mountpoint-s3/src/main.rs

@@ -506,7 +506,7 @@ fn mount(args: CliArgs) -> anyhow::Result<FuseSession> {
             // TODO: Review default for TTL
             let metadata_cache_ttl = args.metadata_cache_ttl.unwrap_or(Duration::from_secs(3600));
             filesystem_config.cache_config = CacheConfig {
-                prefer_s3: false,
+                serve_lookup_from_cache: true,
                 dir_ttl: metadata_cache_ttl,
                 file_ttl: metadata_cache_ttl,
             };

mountpoint-s3/tests/fuse_tests/lookup_test.rs

@@ -111,7 +111,7 @@ where
 {
     let filesystem_config = S3FilesystemConfig {
         cache_config: CacheConfig {
-            prefer_s3: true,
+            serve_lookup_from_cache: false,
             file_ttl: Duration::ZERO,
             dir_ttl: Duration::ZERO,
         },

mountpoint-s3/tests/reftests/harness.rs

@@ -888,7 +888,7 @@ mod mutations {
             allow_delete: true,
             cache_config: CacheConfig {
                 // We are only interested in strong consistency for the reference tests. FUSE isn't even in the loop.
-                prefer_s3: true,
+                serve_lookup_from_cache: false,
                 dir_ttl: Duration::ZERO,
                 file_ttl: Duration::ZERO,
             },