X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/307188e3e1abfc9d1b1179d203454ffe8be36097..2d3726dd11046146731f7f7391659a5eaf44702b:/services/keep-web/webdav.go

diff --git a/services/keep-web/webdav.go b/services/keep-web/webdav.go
index 87d9c47f14..af83681f9c 100644
--- a/services/keep-web/webdav.go
+++ b/services/keep-web/webdav.go
@@ -8,8 +8,11 @@ import (
 	"crypto/rand"
 	"errors"
 	"fmt"
+	"io"
 	prand "math/rand"
 	"os"
+	"path"
+	"strings"
 	"sync/atomic"
 	"time"
 
@@ -27,49 +30,98 @@ var (
 
 // webdavFS implements a webdav.FileSystem by wrapping an
 // arvados.CollectionFilesystem.
+//
+// Collections don't preserve empty directories, so Mkdir is
+// effectively a no-op, and we need to make parent dirs spring into
+// existence automatically so sequences like "mkcol foo; put foo/bar"
+// work as expected.
 type webdavFS struct {
-	collfs arvados.CollectionFileSystem
-	update func() error
+	collfs  arvados.CollectionFileSystem
+	writing bool
+	// webdav PROPFIND reads the first few bytes of each file
+	// whose filename extension isn't recognized, which is
+	// prohibitively expensive: we end up fetching multiple 64MiB
+	// blocks. Avoid this by returning EOF on all reads when
+	// handling a PROPFIND.
+	alwaysReadEOF bool
+}
+
+func (fs *webdavFS) makeparents(name string) {
+	dir, name := path.Split(name)
+	if dir == "" || dir == "/" {
+		return
+	}
+	dir = dir[:len(dir)-1]
+	fs.makeparents(dir)
+	fs.collfs.Mkdir(dir, 0755)
 }
 
 func (fs *webdavFS) Mkdir(ctx context.Context, name string, perm os.FileMode) error {
+	if !fs.writing {
+		return errReadOnly
+	}
+	name = strings.TrimRight(name, "/")
+	fs.makeparents(name)
 	return fs.collfs.Mkdir(name, 0755)
 }
 
 func (fs *webdavFS) OpenFile(ctx context.Context, name string, flag int, perm os.FileMode) (f webdav.File, err error) {
 	writing := flag&(os.O_WRONLY|os.O_RDWR) != 0
-	if writing && fs.update == nil {
-		return nil, errReadOnly
+	if writing {
+		fs.makeparents(name)
 	}
 	f, err = fs.collfs.OpenFile(name, flag, perm)
-	if writing && err == nil {
-		f = writingFile{File: f, update: fs.update}
+	if !fs.writing {
+		// webdav module returns 404 on all OpenFile errors,
+		// but returns 405 Method Not Allowed if OpenFile()
+		// succeeds but Write() or Close() fails. We'd rather
+		// have 405.
+		f = writeFailer{File: f, err: errReadOnly}
+	}
+	if fs.alwaysReadEOF {
+		f = readEOF{File: f}
 	}
 	return
 }
 
 func (fs *webdavFS) RemoveAll(ctx context.Context, name string) error {
-	return errReadOnly
+	return fs.collfs.RemoveAll(name)
 }
 
 func (fs *webdavFS) Rename(ctx context.Context, oldName, newName string) error {
-	return errReadOnly
+	if !fs.writing {
+		return errReadOnly
+	}
+	fs.makeparents(newName)
+	return fs.collfs.Rename(oldName, newName)
 }
 
 func (fs *webdavFS) Stat(ctx context.Context, name string) (os.FileInfo, error) {
+	if fs.writing {
+		fs.makeparents(name)
+	}
 	return fs.collfs.Stat(name)
 }
 
-type writingFile struct {
+type writeFailer struct {
 	webdav.File
-	update func() error
+	err error
 }
 
-func (f writingFile) Close() error {
-	if err := f.File.Close(); err != nil || f.update == nil {
-		return err
-	}
-	return f.update()
+func (wf writeFailer) Write([]byte) (int, error) {
+	return 0, wf.err
+}
+
+func (wf writeFailer) Close() error {
+	return wf.err
+}
+
+type readEOF struct {
+	webdav.File
+}
+
+func (readEOF) Read(p []byte) (int, error) {
+	return 0, io.EOF
 }
 
 // noLockSystem implements webdav.LockSystem by returning success for