diff options
| author | Jakob Unterwurzacher | 2017-03-18 16:01:50 +0100 |
|---|---|---|
| committer | Jakob Unterwurzacher | 2017-03-18 16:18:00 +0100 |
| commit | 00df0771e3dd9fba0992cbc9a7d347f25aff856a (patch) | |
| tree | 62c7a234184413ffd8250579d0c7935aa2941553 /internal/fusefrontend | |
| parent | 14038a1644f17f50b113a05d09a2a0a3b3e973b2 (diff) | |
serialize_reads: add read serialization logic
Due to kernel readahead, we usually get multiple read requests
at the same time. These get submitted to the backing storage in
random order, which is a problem if seeking is very expensive.
Details: https://github.com/rfjakob/gocryptfs/issues/92
Diffstat (limited to 'internal/fusefrontend')
| -rw-r--r-- | internal/fusefrontend/args.go | 2 | ||||
| -rw-r--r-- | internal/fusefrontend/file.go | 11 | ||||
| -rw-r--r-- | internal/fusefrontend/fs.go | 5 |
3 files changed, 18 insertions, 0 deletions
diff --git a/internal/fusefrontend/args.go b/internal/fusefrontend/args.go index f76848d..4029913 100644 --- a/internal/fusefrontend/args.go +++ b/internal/fusefrontend/args.go @@ -27,4 +27,6 @@ type Args struct { // Use HKDF key derivation. // Corresponds to the HKDF feature flag introduced in gocryptfs v1.3. HKDF bool + // Try to serialize read operations, "-serialize_reads" + SerializeReads bool } diff --git a/internal/fusefrontend/file.go b/internal/fusefrontend/file.go index dac7510..b41f220 100644 --- a/internal/fusefrontend/file.go +++ b/internal/fusefrontend/file.go @@ -17,6 +17,7 @@ import ( "github.com/hanwen/go-fuse/fuse/nodefs" "github.com/rfjakob/gocryptfs/internal/contentenc" + "github.com/rfjakob/gocryptfs/internal/serialize_reads" "github.com/rfjakob/gocryptfs/internal/syscallcompat" "github.com/rfjakob/gocryptfs/internal/tlog" ) @@ -176,6 +177,7 @@ func (f *file) doRead(off uint64, length uint64) ([]byte, fuse.Status) { alignedOffset, alignedLength := blocks[0].JointCiphertextRange(blocks) skip := blocks[0].Skip tlog.Debug.Printf("JointCiphertextRange(%d, %d) -> %d, %d, %d", off, length, alignedOffset, alignedLength, skip) + ciphertext := make([]byte, int(alignedLength)) n, err := f.fd.ReadAt(ciphertext, int64(alignedOffset)) // We don't care if the file ID changes after we have read the data. Drop the lock. @@ -224,8 +226,17 @@ func (f *file) Read(buf []byte, off int64) (resultData fuse.ReadResult, code fus return nil, fuse.EBADF } + if f.fs.args.SerializeReads { + serialize_reads.Wait(off, len(buf)) + } + + fmt.Printf("%02d\n", off/131072) out, status := f.doRead(uint64(off), uint64(len(buf))) + if f.fs.args.SerializeReads { + serialize_reads.Done() + } + if status == fuse.EIO { tlog.Warn.Printf("ino%d: Read: returning EIO, offset=%d, length=%d", f.devIno.ino, len(buf), off) } diff --git a/internal/fusefrontend/fs.go b/internal/fusefrontend/fs.go index 9ffcff1..28c43b6 100644 --- a/internal/fusefrontend/fs.go +++ b/internal/fusefrontend/fs.go @@ -17,6 +17,7 @@ import ( "github.com/rfjakob/gocryptfs/internal/contentenc" "github.com/rfjakob/gocryptfs/internal/cryptocore" "github.com/rfjakob/gocryptfs/internal/nametransform" + "github.com/rfjakob/gocryptfs/internal/serialize_reads" "github.com/rfjakob/gocryptfs/internal/syscallcompat" "github.com/rfjakob/gocryptfs/internal/tlog" ) @@ -43,6 +44,10 @@ func NewFS(args Args) *FS { contentEnc := contentenc.New(cryptoCore, contentenc.DefaultBS) nameTransform := nametransform.New(cryptoCore.EMECipher, args.LongNames, args.Raw64) + if args.SerializeReads { + serialize_reads.Init() + } + return &FS{ FileSystem: pathfs.NewLoopbackFileSystem(args.Cipherdir), args: args, |