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authorgVisor bot <gvisor-bot@google.com>2020-12-05 03:16:38 +0000
committergVisor bot <gvisor-bot@google.com>2020-12-05 03:16:38 +0000
commit8a9c95395dc28321dfdf43297eda1c90ef8aeff9 (patch)
tree574daf88ebacd40d42003900894b4b9558764464 /pkg
parent84ffd9bfe74f39dfacd655b511cd336ba08e2f21 (diff)
parentb80021afd2395fd40464ebbeac8f4c8034dee06e (diff)
Merge release-20201130.0-45-gb80021afd (automated)
Diffstat (limited to 'pkg')
-rw-r--r--pkg/sentry/fsimpl/overlay/copy_up.go23
-rw-r--r--pkg/sentry/vfs/file_description.go26
2 files changed, 29 insertions, 20 deletions
diff --git a/pkg/sentry/fsimpl/overlay/copy_up.go b/pkg/sentry/fsimpl/overlay/copy_up.go
index 469f3a33d..27b00cf6f 100644
--- a/pkg/sentry/fsimpl/overlay/copy_up.go
+++ b/pkg/sentry/fsimpl/overlay/copy_up.go
@@ -16,7 +16,6 @@ package overlay
import (
"fmt"
- "io"
"sync/atomic"
"gvisor.dev/gvisor/pkg/abi/linux"
@@ -129,25 +128,9 @@ func (d *dentry) copyUpLocked(ctx context.Context) error {
return err
}
defer newFD.DecRef(ctx)
- bufIOSeq := usermem.BytesIOSequence(make([]byte, 32*1024)) // arbitrary buffer size
- for {
- readN, readErr := oldFD.Read(ctx, bufIOSeq, vfs.ReadOptions{})
- if readErr != nil && readErr != io.EOF {
- cleanupUndoCopyUp()
- return readErr
- }
- total := int64(0)
- for total < readN {
- writeN, writeErr := newFD.Write(ctx, bufIOSeq.DropFirst64(total), vfs.WriteOptions{})
- total += writeN
- if writeErr != nil {
- cleanupUndoCopyUp()
- return writeErr
- }
- }
- if readErr == io.EOF {
- break
- }
+ if _, err := vfs.CopyRegularFileData(ctx, newFD, oldFD); err != nil {
+ cleanupUndoCopyUp()
+ return err
}
d.mapsMu.Lock()
defer d.mapsMu.Unlock()
diff --git a/pkg/sentry/vfs/file_description.go b/pkg/sentry/vfs/file_description.go
index 2153382e9..5321ac80a 100644
--- a/pkg/sentry/vfs/file_description.go
+++ b/pkg/sentry/vfs/file_description.go
@@ -15,6 +15,7 @@
package vfs
import (
+ "io"
"sync/atomic"
"gvisor.dev/gvisor/pkg/abi/linux"
@@ -838,3 +839,28 @@ func (fd *FileDescription) SetAsyncHandler(newHandler func() FileAsync) FileAsyn
}
return fd.asyncHandler
}
+
+// CopyRegularFileData copies data from srcFD to dstFD until reading from srcFD
+// returns EOF or an error. It returns the number of bytes copied.
+func CopyRegularFileData(ctx context.Context, dstFD, srcFD *FileDescription) (int64, error) {
+ done := int64(0)
+ buf := usermem.BytesIOSequence(make([]byte, 32*1024)) // arbitrary buffer size
+ for {
+ readN, readErr := srcFD.Read(ctx, buf, ReadOptions{})
+ if readErr != nil && readErr != io.EOF {
+ return done, readErr
+ }
+ src := buf.TakeFirst64(readN)
+ for src.NumBytes() != 0 {
+ writeN, writeErr := dstFD.Write(ctx, src, WriteOptions{})
+ done += writeN
+ src = src.DropFirst64(writeN)
+ if writeErr != nil {
+ return done, writeErr
+ }
+ }
+ if readErr == io.EOF {
+ return done, nil
+ }
+ }
+}