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authorDean Deng <deandeng@google.com>2020-01-16 12:33:07 -0800
committergVisor bot <gvisor-bot@google.com>2020-01-16 12:56:33 -0800
commit07f258497932e53f4651b80a086117ffda843fe3 (patch)
tree25d38f5c7d17bf532a3e330bc860b1d2248cbf78 /pkg/sentry/fs/fsutil
parent7b7c31820b83abcfe43f7170eff1f7953f3f27e2 (diff)
Plumb getting/setting xattrs through InodeOperations and 9p gofer interfaces.
There was a very bare get/setxattr in the InodeOperations interface. Add context.Context to both, size to getxattr, and flags to setxattr. Note that extended attributes are passed around as strings in this implementation, so size is automatically encoded into the value. Size is added in getxattr so that implementations can return ERANGE if a value is larger than can fit in the user-allocated buffer. This prevents us from unnecessarily passing around an arbitrarily large xattr when the user buffer is actually too small. Don't use the existing xattrwalk and xattrcreate messages and define our own, mainly for the sake of simplicity. Extended attributes will be implemented in future commits. PiperOrigin-RevId: 290121300
Diffstat (limited to 'pkg/sentry/fs/fsutil')
-rw-r--r--pkg/sentry/fs/fsutil/inode.go41
1 files changed, 27 insertions, 14 deletions
diff --git a/pkg/sentry/fs/fsutil/inode.go b/pkg/sentry/fs/fsutil/inode.go
index adf5ec69c..df7b74855 100644
--- a/pkg/sentry/fs/fsutil/inode.go
+++ b/pkg/sentry/fs/fsutil/inode.go
@@ -15,6 +15,7 @@
package fsutil
import (
+ "gvisor.dev/gvisor/pkg/abi/linux"
"gvisor.dev/gvisor/pkg/sentry/context"
"gvisor.dev/gvisor/pkg/sentry/fs"
ktime "gvisor.dev/gvisor/pkg/sentry/kernel/time"
@@ -202,7 +203,7 @@ func (i *InodeSimpleAttributes) NotifyModificationAndStatusChange(ctx context.Co
}
// InodeSimpleExtendedAttributes implements
-// fs.InodeOperations.{Get,Set,List}xattr.
+// fs.InodeOperations.{Get,Set,List}Xattr.
//
// +stateify savable
type InodeSimpleExtendedAttributes struct {
@@ -211,8 +212,8 @@ type InodeSimpleExtendedAttributes struct {
xattrs map[string]string
}
-// Getxattr implements fs.InodeOperations.Getxattr.
-func (i *InodeSimpleExtendedAttributes) Getxattr(_ *fs.Inode, name string) (string, error) {
+// GetXattr implements fs.InodeOperations.GetXattr.
+func (i *InodeSimpleExtendedAttributes) GetXattr(_ context.Context, _ *fs.Inode, name string, _ uint64) (string, error) {
i.mu.RLock()
value, ok := i.xattrs[name]
i.mu.RUnlock()
@@ -222,19 +223,31 @@ func (i *InodeSimpleExtendedAttributes) Getxattr(_ *fs.Inode, name string) (stri
return value, nil
}
-// Setxattr implements fs.InodeOperations.Setxattr.
-func (i *InodeSimpleExtendedAttributes) Setxattr(_ *fs.Inode, name, value string) error {
+// SetXattr implements fs.InodeOperations.SetXattr.
+func (i *InodeSimpleExtendedAttributes) SetXattr(_ context.Context, _ *fs.Inode, name, value string, flags uint32) error {
i.mu.Lock()
+ defer i.mu.Unlock()
if i.xattrs == nil {
+ if flags&linux.XATTR_REPLACE != 0 {
+ return syserror.ENODATA
+ }
i.xattrs = make(map[string]string)
}
+
+ _, ok := i.xattrs[name]
+ if ok && flags&linux.XATTR_CREATE != 0 {
+ return syserror.EEXIST
+ }
+ if !ok && flags&linux.XATTR_REPLACE != 0 {
+ return syserror.ENODATA
+ }
+
i.xattrs[name] = value
- i.mu.Unlock()
return nil
}
-// Listxattr implements fs.InodeOperations.Listxattr.
-func (i *InodeSimpleExtendedAttributes) Listxattr(_ *fs.Inode) (map[string]struct{}, error) {
+// ListXattr implements fs.InodeOperations.ListXattr.
+func (i *InodeSimpleExtendedAttributes) ListXattr(context.Context, *fs.Inode) (map[string]struct{}, error) {
i.mu.RLock()
names := make(map[string]struct{}, len(i.xattrs))
for name := range i.xattrs {
@@ -436,18 +449,18 @@ func (InodeNotSymlink) Getlink(context.Context, *fs.Inode) (*fs.Dirent, error) {
// extended attributes.
type InodeNoExtendedAttributes struct{}
-// Getxattr implements fs.InodeOperations.Getxattr.
-func (InodeNoExtendedAttributes) Getxattr(*fs.Inode, string) (string, error) {
+// GetXattr implements fs.InodeOperations.GetXattr.
+func (InodeNoExtendedAttributes) GetXattr(context.Context, *fs.Inode, string, uint64) (string, error) {
return "", syserror.EOPNOTSUPP
}
-// Setxattr implements fs.InodeOperations.Setxattr.
-func (InodeNoExtendedAttributes) Setxattr(*fs.Inode, string, string) error {
+// SetXattr implements fs.InodeOperations.SetXattr.
+func (InodeNoExtendedAttributes) SetXattr(context.Context, *fs.Inode, string, string, uint32) error {
return syserror.EOPNOTSUPP
}
-// Listxattr implements fs.InodeOperations.Listxattr.
-func (InodeNoExtendedAttributes) Listxattr(*fs.Inode) (map[string]struct{}, error) {
+// ListXattr implements fs.InodeOperations.ListXattr.
+func (InodeNoExtendedAttributes) ListXattr(context.Context, *fs.Inode) (map[string]struct{}, error) {
return nil, syserror.EOPNOTSUPP
}