diff options
| author | Ayush Ranjan <ayushranjan@google.com> | 2020-10-26 16:13:04 -0700 |
|---|---|---|
| committer | gVisor bot <gvisor-bot@google.com> | 2020-10-26 16:14:53 -0700 |
| commit | 652f11380e44b7c2083fa19d706f5cddf7fe0718 (patch) | |
| tree | 77e52a0b2078faf589b670e9e7117bf2bf6b6785 /pkg/sentry/fsimpl/sys | |
| parent | 0bdcee38bdfa5c4585d28a0edd0c46e170cdc9b5 (diff) | |
[vfs] kernfs: Implement LRU cache for kernfs dentries.
Much like the VFS2 gofer client, kernfs too now caches dentries. The size of the
LRU cache is configurable via mount options.
Have adopted the same reference semantics from gofer client dentry.
Only sysfs and procfs use this LRU cache. The rest of the kernfs users (devpts,
fusefs, host, pipefs, sockfs) still use the no cache approach.
PiperOrigin-RevId: 339139835
Diffstat (limited to 'pkg/sentry/fsimpl/sys')
| -rw-r--r-- | pkg/sentry/fsimpl/sys/sys.go | 22 |
1 files changed, 19 insertions, 3 deletions
diff --git a/pkg/sentry/fsimpl/sys/sys.go b/pkg/sentry/fsimpl/sys/sys.go index 54fa5eced..7d2147141 100644 --- a/pkg/sentry/fsimpl/sys/sys.go +++ b/pkg/sentry/fsimpl/sys/sys.go @@ -18,6 +18,7 @@ package sys import ( "bytes" "fmt" + "strconv" "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" @@ -29,9 +30,12 @@ import ( "gvisor.dev/gvisor/pkg/syserror" ) -// Name is the default filesystem name. -const Name = "sysfs" -const defaultSysDirMode = linux.FileMode(0755) +const ( + // Name is the default filesystem name. + Name = "sysfs" + defaultSysDirMode = linux.FileMode(0755) + defaultMaxCachedDentries = uint64(1000) +) // FilesystemType implements vfs.FilesystemType. // @@ -62,9 +66,21 @@ func (fsType FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.Virt return nil, nil, err } + mopts := vfs.GenericParseMountOptions(opts.Data) + maxCachedDentries := defaultMaxCachedDentries + if str, ok := mopts["dentry_cache_limit"]; ok { + delete(mopts, "dentry_cache_limit") + maxCachedDentries, err = strconv.ParseUint(str, 10, 64) + if err != nil { + ctx.Warningf("sys.FilesystemType.GetFilesystem: invalid dentry cache limit: dentry_cache_limit=%s", str) + return nil, nil, syserror.EINVAL + } + } + fs := &filesystem{ devMinor: devMinor, } + fs.MaxCachedDentries = maxCachedDentries fs.VFSFilesystem().Init(vfsObj, &fsType, fs) root := fs.newDir(ctx, creds, defaultSysDirMode, map[string]kernfs.Inode{ |