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-rw-r--r--pkg/sentry/fsimpl/ext/dentry.go11
-rw-r--r--pkg/sentry/fsimpl/gofer/directory.go1
-rw-r--r--pkg/sentry/fsimpl/gofer/filesystem.go59
-rw-r--r--pkg/sentry/fsimpl/gofer/gofer.go73
-rw-r--r--pkg/sentry/fsimpl/kernfs/kernfs.go7
-rw-r--r--pkg/sentry/fsimpl/overlay/overlay.go5
-rw-r--r--pkg/sentry/fsimpl/tmpfs/directory.go4
-rw-r--r--pkg/sentry/fsimpl/tmpfs/filesystem.go12
-rw-r--r--pkg/sentry/fsimpl/tmpfs/tmpfs.go19
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/inotify.go7
-rw-r--r--pkg/sentry/vfs/anonfs.go7
-rw-r--r--pkg/sentry/vfs/dentry.go32
-rw-r--r--pkg/sentry/vfs/inotify.go108
-rw-r--r--pkg/sentry/vfs/vfs.go3
-rw-r--r--test/syscalls/linux/BUILD1
-rw-r--r--test/syscalls/linux/inotify.cc251
16 files changed, 523 insertions, 77 deletions
diff --git a/pkg/sentry/fsimpl/ext/dentry.go b/pkg/sentry/fsimpl/ext/dentry.go
index 6bd1a9fc6..55902322a 100644
--- a/pkg/sentry/fsimpl/ext/dentry.go
+++ b/pkg/sentry/fsimpl/ext/dentry.go
@@ -63,12 +63,17 @@ func (d *dentry) DecRef() {
// InotifyWithParent implements vfs.DentryImpl.InotifyWithParent.
//
-// TODO(gvisor.dev/issue/1479): Implement inotify.
-func (d *dentry) InotifyWithParent(events uint32, cookie uint32, et vfs.EventType) {}
+// TODO(b/134676337): Implement inotify.
+func (d *dentry) InotifyWithParent(events, cookie uint32, et vfs.EventType) {}
// Watches implements vfs.DentryImpl.Watches.
//
-// TODO(gvisor.dev/issue/1479): Implement inotify.
+// TODO(b/134676337): Implement inotify.
func (d *dentry) Watches() *vfs.Watches {
return nil
}
+
+// OnZeroWatches implements vfs.Dentry.OnZeroWatches.
+//
+// TODO(b/134676337): Implement inotify.
+func (d *dentry) OnZeroWatches() {}
diff --git a/pkg/sentry/fsimpl/gofer/directory.go b/pkg/sentry/fsimpl/gofer/directory.go
index 480510b2a..5d83fe363 100644
--- a/pkg/sentry/fsimpl/gofer/directory.go
+++ b/pkg/sentry/fsimpl/gofer/directory.go
@@ -138,6 +138,7 @@ func (fd *directoryFD) IterDirents(ctx context.Context, cb vfs.IterDirentsCallba
fd.dirents = ds
}
+ d.InotifyWithParent(linux.IN_ACCESS, 0, vfs.PathEvent)
if d.cachedMetadataAuthoritative() {
d.touchAtime(fd.vfsfd.Mount())
}
diff --git a/pkg/sentry/fsimpl/gofer/filesystem.go b/pkg/sentry/fsimpl/gofer/filesystem.go
index f065c4bad..0321fd384 100644
--- a/pkg/sentry/fsimpl/gofer/filesystem.go
+++ b/pkg/sentry/fsimpl/gofer/filesystem.go
@@ -371,6 +371,11 @@ func (fs *filesystem) doCreateAt(ctx context.Context, rp *vfs.ResolvingPath, dir
}
parent.touchCMtime()
parent.dirents = nil
+ ev := linux.IN_CREATE
+ if dir {
+ ev |= linux.IN_ISDIR
+ }
+ parent.watches.Notify(name, uint32(ev), 0, vfs.InodeEvent)
return nil
}
if fs.opts.interop == InteropModeShared {
@@ -400,6 +405,11 @@ func (fs *filesystem) doCreateAt(ctx context.Context, rp *vfs.ResolvingPath, dir
}
parent.touchCMtime()
parent.dirents = nil
+ ev := linux.IN_CREATE
+ if dir {
+ ev |= linux.IN_ISDIR
+ }
+ parent.watches.Notify(name, uint32(ev), 0, vfs.InodeEvent)
return nil
}
@@ -530,6 +540,18 @@ func (fs *filesystem) unlinkAt(ctx context.Context, rp *vfs.ResolvingPath, dir b
return err
}
}
+
+ // Generate inotify events for rmdir or unlink.
+ if dir {
+ parent.watches.Notify(name, linux.IN_DELETE|linux.IN_ISDIR, 0, vfs.InodeEvent)
+ } else {
+ var cw *vfs.Watches
+ if child != nil {
+ cw = &child.watches
+ }
+ vfs.InotifyRemoveChild(cw, &parent.watches, name)
+ }
+
if child != nil {
vfsObj.CommitDeleteDentry(&child.vfsd)
child.setDeleted()
@@ -1018,6 +1040,7 @@ func (d *dentry) createAndOpenChildLocked(ctx context.Context, rp *vfs.Resolving
}
childVFSFD = &fd.vfsfd
}
+ d.watches.Notify(name, linux.IN_CREATE, 0, vfs.PathEvent)
return childVFSFD, nil
}
@@ -1203,6 +1226,7 @@ func (fs *filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa
newParent.incLinks()
}
}
+ vfs.InotifyRename(ctx, &renamed.watches, &oldParent.watches, &newParent.watches, oldName, newName, renamed.isDir())
return nil
}
@@ -1215,12 +1239,21 @@ func (fs *filesystem) RmdirAt(ctx context.Context, rp *vfs.ResolvingPath) error
func (fs *filesystem) SetStatAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.SetStatOptions) error {
var ds *[]*dentry
fs.renameMu.RLock()
- defer fs.renameMuRUnlockAndCheckCaching(&ds)
d, err := fs.resolveLocked(ctx, rp, &ds)
if err != nil {
+ fs.renameMuRUnlockAndCheckCaching(&ds)
+ return err
+ }
+ if err := d.setStat(ctx, rp.Credentials(), &opts.Stat, rp.Mount()); err != nil {
+ fs.renameMuRUnlockAndCheckCaching(&ds)
return err
}
- return d.setStat(ctx, rp.Credentials(), &opts.Stat, rp.Mount())
+ fs.renameMuRUnlockAndCheckCaching(&ds)
+
+ if ev := vfs.InotifyEventFromStatMask(opts.Stat.Mask); ev != 0 {
+ d.InotifyWithParent(ev, 0, vfs.InodeEvent)
+ }
+ return nil
}
// StatAt implements vfs.FilesystemImpl.StatAt.
@@ -1344,24 +1377,38 @@ func (fs *filesystem) GetxattrAt(ctx context.Context, rp *vfs.ResolvingPath, opt
func (fs *filesystem) SetxattrAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.SetxattrOptions) error {
var ds *[]*dentry
fs.renameMu.RLock()
- defer fs.renameMuRUnlockAndCheckCaching(&ds)
d, err := fs.resolveLocked(ctx, rp, &ds)
if err != nil {
+ fs.renameMuRUnlockAndCheckCaching(&ds)
return err
}
- return d.setxattr(ctx, rp.Credentials(), &opts)
+ if err := d.setxattr(ctx, rp.Credentials(), &opts); err != nil {
+ fs.renameMuRUnlockAndCheckCaching(&ds)
+ return err
+ }
+ fs.renameMuRUnlockAndCheckCaching(&ds)
+
+ d.InotifyWithParent(linux.IN_ATTRIB, 0, vfs.InodeEvent)
+ return nil
}
// RemovexattrAt implements vfs.FilesystemImpl.RemovexattrAt.
func (fs *filesystem) RemovexattrAt(ctx context.Context, rp *vfs.ResolvingPath, name string) error {
var ds *[]*dentry
fs.renameMu.RLock()
- defer fs.renameMuRUnlockAndCheckCaching(&ds)
d, err := fs.resolveLocked(ctx, rp, &ds)
if err != nil {
+ fs.renameMuRUnlockAndCheckCaching(&ds)
+ return err
+ }
+ if err := d.removexattr(ctx, rp.Credentials(), name); err != nil {
+ fs.renameMuRUnlockAndCheckCaching(&ds)
return err
}
- return d.removexattr(ctx, rp.Credentials(), name)
+ fs.renameMuRUnlockAndCheckCaching(&ds)
+
+ d.InotifyWithParent(linux.IN_ATTRIB, 0, vfs.InodeEvent)
+ return nil
}
// PrependPath implements vfs.FilesystemImpl.PrependPath.
diff --git a/pkg/sentry/fsimpl/gofer/gofer.go b/pkg/sentry/fsimpl/gofer/gofer.go
index 43c8153a4..c6c284ff3 100644
--- a/pkg/sentry/fsimpl/gofer/gofer.go
+++ b/pkg/sentry/fsimpl/gofer/gofer.go
@@ -665,6 +665,9 @@ type dentry struct {
pipe *pipe.VFSPipe
locks vfs.FileLocks
+
+ // Inotify watches for this dentry.
+ watches vfs.Watches
}
// dentryAttrMask returns a p9.AttrMask enabling all attributes used by the
@@ -947,6 +950,8 @@ func (d *dentry) setStat(ctx context.Context, creds *auth.Credentials, stat *lin
} else {
atomic.StoreInt64(&d.atime, dentryTimestampFromStatx(stat.Atime))
}
+ // Restore mask bits that we cleared earlier.
+ stat.Mask |= linux.STATX_ATIME
}
if setLocalMtime {
if stat.Mtime.Nsec == linux.UTIME_NOW {
@@ -954,6 +959,8 @@ func (d *dentry) setStat(ctx context.Context, creds *auth.Credentials, stat *lin
} else {
atomic.StoreInt64(&d.mtime, dentryTimestampFromStatx(stat.Mtime))
}
+ // Restore mask bits that we cleared earlier.
+ stat.Mask |= linux.STATX_MTIME
}
atomic.StoreInt64(&d.ctime, now)
if stat.Mask&linux.STATX_SIZE != 0 {
@@ -1051,15 +1058,34 @@ func (d *dentry) decRefLocked() {
}
// InotifyWithParent implements vfs.DentryImpl.InotifyWithParent.
-//
-// TODO(gvisor.dev/issue/1479): Implement inotify.
-func (d *dentry) InotifyWithParent(events uint32, cookie uint32, et vfs.EventType) {}
+func (d *dentry) InotifyWithParent(events, cookie uint32, et vfs.EventType) {
+ if d.isDir() {
+ events |= linux.IN_ISDIR
+ }
+
+ d.fs.renameMu.RLock()
+ // The ordering below is important, Linux always notifies the parent first.
+ if d.parent != nil {
+ d.parent.watches.NotifyWithExclusions(d.name, events, cookie, et, d.isDeleted())
+ }
+ d.watches.Notify("", events, cookie, et)
+ d.fs.renameMu.RUnlock()
+}
// Watches implements vfs.DentryImpl.Watches.
-//
-// TODO(gvisor.dev/issue/1479): Implement inotify.
func (d *dentry) Watches() *vfs.Watches {
- return nil
+ return &d.watches
+}
+
+// OnZeroWatches implements vfs.DentryImpl.OnZeroWatches.
+//
+// If no watches are left on this dentry and it has no references, cache it.
+func (d *dentry) OnZeroWatches() {
+ if atomic.LoadInt64(&d.refs) == 0 {
+ d.fs.renameMu.Lock()
+ d.checkCachingLocked()
+ d.fs.renameMu.Unlock()
+ }
}
// checkCachingLocked should be called after d's reference count becomes 0 or it
@@ -1093,6 +1119,9 @@ func (d *dentry) checkCachingLocked() {
// Deleted and invalidated dentries with zero references are no longer
// reachable by path resolution and should be dropped immediately.
if d.vfsd.IsDead() {
+ if d.isDeleted() {
+ d.watches.HandleDeletion()
+ }
if d.cached {
d.fs.cachedDentries.Remove(d)
d.fs.cachedDentriesLen--
@@ -1101,6 +1130,14 @@ func (d *dentry) checkCachingLocked() {
d.destroyLocked()
return
}
+ // If d still has inotify watches and it is not deleted or invalidated, we
+ // cannot cache it and allow it to be evicted. Otherwise, we will lose its
+ // watches, even if a new dentry is created for the same file in the future.
+ // Note that the size of d.watches cannot concurrently transition from zero
+ // to non-zero, because adding a watch requires holding a reference on d.
+ if d.watches.Size() > 0 {
+ return
+ }
// If d is already cached, just move it to the front of the LRU.
if d.cached {
d.fs.cachedDentries.Remove(d)
@@ -1277,7 +1314,7 @@ func (d *dentry) userXattrSupported() bool {
return filetype == linux.S_IFREG || filetype == linux.S_IFDIR
}
-// Preconditions: !d.isSynthetic(). d.isRegularFile() || d.isDirectory().
+// Preconditions: !d.isSynthetic(). d.isRegularFile() || d.isDir().
func (d *dentry) ensureSharedHandle(ctx context.Context, read, write, trunc bool) error {
// O_TRUNC unconditionally requires us to obtain a new handle (opened with
// O_TRUNC).
@@ -1422,7 +1459,13 @@ func (fd *fileDescription) Stat(ctx context.Context, opts vfs.StatOptions) (linu
// SetStat implements vfs.FileDescriptionImpl.SetStat.
func (fd *fileDescription) SetStat(ctx context.Context, opts vfs.SetStatOptions) error {
- return fd.dentry().setStat(ctx, auth.CredentialsFromContext(ctx), &opts.Stat, fd.vfsfd.Mount())
+ if err := fd.dentry().setStat(ctx, auth.CredentialsFromContext(ctx), &opts.Stat, fd.vfsfd.Mount()); err != nil {
+ return err
+ }
+ if ev := vfs.InotifyEventFromStatMask(opts.Stat.Mask); ev != 0 {
+ fd.dentry().InotifyWithParent(ev, 0, vfs.InodeEvent)
+ }
+ return nil
}
// Listxattr implements vfs.FileDescriptionImpl.Listxattr.
@@ -1437,12 +1480,22 @@ func (fd *fileDescription) Getxattr(ctx context.Context, opts vfs.GetxattrOption
// Setxattr implements vfs.FileDescriptionImpl.Setxattr.
func (fd *fileDescription) Setxattr(ctx context.Context, opts vfs.SetxattrOptions) error {
- return fd.dentry().setxattr(ctx, auth.CredentialsFromContext(ctx), &opts)
+ d := fd.dentry()
+ if err := d.setxattr(ctx, auth.CredentialsFromContext(ctx), &opts); err != nil {
+ return err
+ }
+ d.InotifyWithParent(linux.IN_ATTRIB, 0, vfs.InodeEvent)
+ return nil
}
// Removexattr implements vfs.FileDescriptionImpl.Removexattr.
func (fd *fileDescription) Removexattr(ctx context.Context, name string) error {
- return fd.dentry().removexattr(ctx, auth.CredentialsFromContext(ctx), name)
+ d := fd.dentry()
+ if err := d.removexattr(ctx, auth.CredentialsFromContext(ctx), name); err != nil {
+ return err
+ }
+ d.InotifyWithParent(linux.IN_ATTRIB, 0, vfs.InodeEvent)
+ return nil
}
// LockBSD implements vfs.FileDescriptionImpl.LockBSD.
diff --git a/pkg/sentry/fsimpl/kernfs/kernfs.go b/pkg/sentry/fsimpl/kernfs/kernfs.go
index 07a9dc830..55349f2a3 100644
--- a/pkg/sentry/fsimpl/kernfs/kernfs.go
+++ b/pkg/sentry/fsimpl/kernfs/kernfs.go
@@ -228,7 +228,7 @@ func (d *Dentry) destroy() {
// InotifyWithParent implements vfs.DentryImpl.InotifyWithParent.
//
// TODO(gvisor.dev/issue/1479): Implement inotify.
-func (d *Dentry) InotifyWithParent(events uint32, cookie uint32, et vfs.EventType) {}
+func (d *Dentry) InotifyWithParent(events, cookie uint32, et vfs.EventType) {}
// Watches implements vfs.DentryImpl.Watches.
//
@@ -237,6 +237,11 @@ func (d *Dentry) Watches() *vfs.Watches {
return nil
}
+// OnZeroWatches implements vfs.Dentry.OnZeroWatches.
+//
+// TODO(gvisor.dev/issue/1479): Implement inotify.
+func (d *Dentry) OnZeroWatches() {}
+
// InsertChild inserts child into the vfs dentry cache with the given name under
// this dentry. This does not update the directory inode, so calling this on
// its own isn't sufficient to insert a child into a directory. InsertChild
diff --git a/pkg/sentry/fsimpl/overlay/overlay.go b/pkg/sentry/fsimpl/overlay/overlay.go
index e11a3ff19..e720d4825 100644
--- a/pkg/sentry/fsimpl/overlay/overlay.go
+++ b/pkg/sentry/fsimpl/overlay/overlay.go
@@ -528,6 +528,11 @@ func (d *dentry) Watches() *vfs.Watches {
return nil
}
+// OnZeroWatches implements vfs.DentryImpl.OnZeroWatches.
+//
+// TODO(gvisor.dev/issue/1479): Implement inotify.
+func (d *dentry) OnZeroWatches() {}
+
// iterLayers invokes yield on each layer comprising d, from top to bottom. If
// any call to yield returns false, iterLayer stops iteration.
func (d *dentry) iterLayers(yield func(vd vfs.VirtualDentry, isUpper bool) bool) {
diff --git a/pkg/sentry/fsimpl/tmpfs/directory.go b/pkg/sentry/fsimpl/tmpfs/directory.go
index 913b8a6c5..b172abc15 100644
--- a/pkg/sentry/fsimpl/tmpfs/directory.go
+++ b/pkg/sentry/fsimpl/tmpfs/directory.go
@@ -79,7 +79,6 @@ func (dir *directory) removeChildLocked(child *dentry) {
dir.iterMu.Lock()
dir.childList.Remove(child)
dir.iterMu.Unlock()
- child.unlinked = true
}
type directoryFD struct {
@@ -107,13 +106,14 @@ func (fd *directoryFD) IterDirents(ctx context.Context, cb vfs.IterDirentsCallba
fs := fd.filesystem()
dir := fd.inode().impl.(*directory)
+ defer fd.dentry().InotifyWithParent(linux.IN_ACCESS, 0, vfs.PathEvent)
+
// fs.mu is required to read d.parent and dentry.name.
fs.mu.RLock()
defer fs.mu.RUnlock()
dir.iterMu.Lock()
defer dir.iterMu.Unlock()
- fd.dentry().InotifyWithParent(linux.IN_ACCESS, 0, vfs.PathEvent)
fd.inode().touchAtime(fd.vfsfd.Mount())
if fd.off == 0 {
diff --git a/pkg/sentry/fsimpl/tmpfs/filesystem.go b/pkg/sentry/fsimpl/tmpfs/filesystem.go
index 637d84e04..85d8e37b2 100644
--- a/pkg/sentry/fsimpl/tmpfs/filesystem.go
+++ b/pkg/sentry/fsimpl/tmpfs/filesystem.go
@@ -638,14 +638,16 @@ func (fs *filesystem) RmdirAt(ctx context.Context, rp *vfs.ResolvingPath) error
// SetStatAt implements vfs.FilesystemImpl.SetStatAt.
func (fs *filesystem) SetStatAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.SetStatOptions) error {
fs.mu.RLock()
- defer fs.mu.RUnlock()
d, err := resolveLocked(rp)
if err != nil {
+ fs.mu.RUnlock()
return err
}
if err := d.inode.setStat(ctx, rp.Credentials(), &opts.Stat); err != nil {
+ fs.mu.RUnlock()
return err
}
+ fs.mu.RUnlock()
if ev := vfs.InotifyEventFromStatMask(opts.Stat.Mask); ev != 0 {
d.InotifyWithParent(ev, 0, vfs.InodeEvent)
@@ -788,14 +790,16 @@ func (fs *filesystem) GetxattrAt(ctx context.Context, rp *vfs.ResolvingPath, opt
// SetxattrAt implements vfs.FilesystemImpl.SetxattrAt.
func (fs *filesystem) SetxattrAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.SetxattrOptions) error {
fs.mu.RLock()
- defer fs.mu.RUnlock()
d, err := resolveLocked(rp)
if err != nil {
+ fs.mu.RUnlock()
return err
}
if err := d.inode.setxattr(rp.Credentials(), &opts); err != nil {
+ fs.mu.RUnlock()
return err
}
+ fs.mu.RUnlock()
d.InotifyWithParent(linux.IN_ATTRIB, 0, vfs.InodeEvent)
return nil
@@ -804,14 +808,16 @@ func (fs *filesystem) SetxattrAt(ctx context.Context, rp *vfs.ResolvingPath, opt
// RemovexattrAt implements vfs.FilesystemImpl.RemovexattrAt.
func (fs *filesystem) RemovexattrAt(ctx context.Context, rp *vfs.ResolvingPath, name string) error {
fs.mu.RLock()
- defer fs.mu.RUnlock()
d, err := resolveLocked(rp)
if err != nil {
+ fs.mu.RUnlock()
return err
}
if err := d.inode.removexattr(rp.Credentials(), name); err != nil {
+ fs.mu.RUnlock()
return err
}
+ fs.mu.RUnlock()
d.InotifyWithParent(linux.IN_ATTRIB, 0, vfs.InodeEvent)
return nil
diff --git a/pkg/sentry/fsimpl/tmpfs/tmpfs.go b/pkg/sentry/fsimpl/tmpfs/tmpfs.go
index a94333ee0..a85bfc968 100644
--- a/pkg/sentry/fsimpl/tmpfs/tmpfs.go
+++ b/pkg/sentry/fsimpl/tmpfs/tmpfs.go
@@ -215,11 +215,6 @@ type dentry struct {
// filesystem.mu.
name string
- // unlinked indicates whether this dentry has been unlinked from its parent.
- // It is only set to true on an unlink operation, and never set from true to
- // false. unlinked is protected by filesystem.mu.
- unlinked bool
-
// dentryEntry (ugh) links dentries into their parent directory.childList.
dentryEntry
@@ -259,18 +254,20 @@ func (d *dentry) DecRef() {
}
// InotifyWithParent implements vfs.DentryImpl.InotifyWithParent.
-func (d *dentry) InotifyWithParent(events uint32, cookie uint32, et vfs.EventType) {
+func (d *dentry) InotifyWithParent(events, cookie uint32, et vfs.EventType) {
if d.inode.isDir() {
events |= linux.IN_ISDIR
}
+ d.inode.fs.mu.RLock()
// The ordering below is important, Linux always notifies the parent first.
if d.parent != nil {
- // Note that d.parent or d.name may be stale if there is a concurrent
- // rename operation. Inotify does not provide consistency guarantees.
- d.parent.inode.watches.NotifyWithExclusions(d.name, events, cookie, et, d.unlinked)
+ // tmpfs never calls VFS.InvalidateDentry(), so d.vfsd.IsDead() indicates
+ // that d was deleted.
+ d.parent.inode.watches.NotifyWithExclusions(d.name, events, cookie, et, d.vfsd.IsDead())
}
d.inode.watches.Notify("", events, cookie, et)
+ d.inode.fs.mu.RUnlock()
}
// Watches implements vfs.DentryImpl.Watches.
@@ -278,6 +275,9 @@ func (d *dentry) Watches() *vfs.Watches {
return &d.inode.watches
}
+// OnZeroWatches implements vfs.Dentry.OnZeroWatches.
+func (d *dentry) OnZeroWatches() {}
+
// inode represents a filesystem object.
type inode struct {
// fs is the owning filesystem. fs is immutable.
@@ -336,7 +336,6 @@ func (i *inode) init(impl interface{}, fs *filesystem, kuid auth.KUID, kgid auth
i.ctime = now
i.mtime = now
// i.nlink initialized by caller
- i.watches = vfs.Watches{}
i.impl = impl
}
diff --git a/pkg/sentry/syscalls/linux/vfs2/inotify.go b/pkg/sentry/syscalls/linux/vfs2/inotify.go
index 7d50b6a16..74e5287b7 100644
--- a/pkg/sentry/syscalls/linux/vfs2/inotify.go
+++ b/pkg/sentry/syscalls/linux/vfs2/inotify.go
@@ -116,8 +116,11 @@ func InotifyAddWatch(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kern
}
defer d.DecRef()
- fd = ino.AddWatch(d.Dentry(), mask)
- return uintptr(fd), nil, err
+ fd, err = ino.AddWatch(d.Dentry(), mask)
+ if err != nil {
+ return 0, nil, err
+ }
+ return uintptr(fd), nil, nil
}
// InotifyRmWatch implements the inotify_rm_watch() syscall.
diff --git a/pkg/sentry/vfs/anonfs.go b/pkg/sentry/vfs/anonfs.go
index b7c6b60b8..746af03ec 100644
--- a/pkg/sentry/vfs/anonfs.go
+++ b/pkg/sentry/vfs/anonfs.go
@@ -301,7 +301,7 @@ func (d *anonDentry) DecRef() {
// InotifyWithParent implements DentryImpl.InotifyWithParent.
//
// TODO(gvisor.dev/issue/1479): Implement inotify.
-func (d *anonDentry) InotifyWithParent(events uint32, cookie uint32, et EventType) {}
+func (d *anonDentry) InotifyWithParent(events, cookie uint32, et EventType) {}
// Watches implements DentryImpl.Watches.
//
@@ -309,3 +309,8 @@ func (d *anonDentry) InotifyWithParent(events uint32, cookie uint32, et EventTyp
func (d *anonDentry) Watches() *Watches {
return nil
}
+
+// OnZeroWatches implements Dentry.OnZeroWatches.
+//
+// TODO(gvisor.dev/issue/1479): Implement inotify.
+func (d *anonDentry) OnZeroWatches() {}
diff --git a/pkg/sentry/vfs/dentry.go b/pkg/sentry/vfs/dentry.go
index 24af13eb1..cea3e6955 100644
--- a/pkg/sentry/vfs/dentry.go
+++ b/pkg/sentry/vfs/dentry.go
@@ -113,12 +113,29 @@ type DentryImpl interface {
//
// Note that the events may not actually propagate up to the user, depending
// on the event masks.
- InotifyWithParent(events uint32, cookie uint32, et EventType)
+ InotifyWithParent(events, cookie uint32, et EventType)
// Watches returns the set of inotify watches for the file corresponding to
// the Dentry. Dentries that are hard links to the same underlying file
// share the same watches.
+ //
+ // Watches may return nil if the dentry belongs to a FilesystemImpl that
+ // does not support inotify. If an implementation returns a non-nil watch
+ // set, it must always return a non-nil watch set. Likewise, if an
+ // implementation returns a nil watch set, it must always return a nil watch
+ // set.
+ //
+ // The caller does not need to hold a reference on the dentry.
Watches() *Watches
+
+ // OnZeroWatches is called whenever the number of watches on a dentry drops
+ // to zero. This is needed by some FilesystemImpls (e.g. gofer) to manage
+ // dentry lifetime.
+ //
+ // The caller does not need to hold a reference on the dentry. OnZeroWatches
+ // may acquire inotify locks, so to prevent deadlock, no inotify locks should
+ // be held by the caller.
+ OnZeroWatches()
}
// IncRef increments d's reference count.
@@ -149,17 +166,26 @@ func (d *Dentry) isMounted() bool {
return atomic.LoadUint32(&d.mounts) != 0
}
-// InotifyWithParent notifies all watches on the inodes for this dentry and
+// InotifyWithParent notifies all watches on the targets represented by d and
// its parent of events.
-func (d *Dentry) InotifyWithParent(events uint32, cookie uint32, et EventType) {
+func (d *Dentry) InotifyWithParent(events, cookie uint32, et EventType) {
d.impl.InotifyWithParent(events, cookie, et)
}
// Watches returns the set of inotify watches associated with d.
+//
+// Watches will return nil if d belongs to a FilesystemImpl that does not
+// support inotify.
func (d *Dentry) Watches() *Watches {
return d.impl.Watches()
}
+// OnZeroWatches performs cleanup tasks whenever the number of watches on a
+// dentry drops to zero.
+func (d *Dentry) OnZeroWatches() {
+ d.impl.OnZeroWatches()
+}
+
// The following functions are exported so that filesystem implementations can
// use them. The vfs package, and users of VFS, should not call these
// functions.
diff --git a/pkg/sentry/vfs/inotify.go b/pkg/sentry/vfs/inotify.go
index 7fa7d2d0c..36e7a3767 100644
--- a/pkg/sentry/vfs/inotify.go
+++ b/pkg/sentry/vfs/inotify.go
@@ -49,9 +49,6 @@ const (
// Inotify represents an inotify instance created by inotify_init(2) or
// inotify_init1(2). Inotify implements FileDescriptionImpl.
//
-// Lock ordering:
-// Inotify.mu -> Watches.mu -> Inotify.evMu
-//
// +stateify savable
type Inotify struct {
vfsfd FileDescription
@@ -122,17 +119,31 @@ func NewInotifyFD(ctx context.Context, vfsObj *VirtualFilesystem, flags uint32)
// Release implements FileDescriptionImpl.Release. Release removes all
// watches and frees all resources for an inotify instance.
func (i *Inotify) Release() {
+ var ds []*Dentry
// We need to hold i.mu to avoid a race with concurrent calls to
// Inotify.handleDeletion from Watches. There's no risk of Watches
// accessing this Inotify after the destructor ends, because we remove all
// references to it below.
i.mu.Lock()
- defer i.mu.Unlock()
for _, w := range i.watches {
// Remove references to the watch from the watches set on the target. We
// don't need to worry about the references from i.watches, since this
// file description is about to be destroyed.
- w.set.Remove(i.id)
+ d := w.target
+ ws := d.Watches()
+ // Watchable dentries should never return a nil watch set.
+ if ws == nil {
+ panic("Cannot remove watch from an unwatchable dentry")
+ }
+ ws.Remove(i.id)
+ if ws.Size() == 0 {
+ ds = append(ds, d)
+ }
+ }
+ i.mu.Unlock()
+
+ for _, d := range ds {
+ d.OnZeroWatches()
}
}
@@ -272,20 +283,19 @@ func (i *Inotify) queueEvent(ev *Event) {
// newWatchLocked creates and adds a new watch to target.
//
-// Precondition: i.mu must be locked.
-func (i *Inotify) newWatchLocked(target *Dentry, mask uint32) *Watch {
- targetWatches := target.Watches()
+// Precondition: i.mu must be locked. ws must be the watch set for target d.
+func (i *Inotify) newWatchLocked(d *Dentry, ws *Watches, mask uint32) *Watch {
w := &Watch{
- owner: i,
- wd: i.nextWatchIDLocked(),
- set: targetWatches,
- mask: mask,
+ owner: i,
+ wd: i.nextWatchIDLocked(),
+ target: d,
+ mask: mask,
}
// Hold the watch in this inotify instance as well as the watch set on the
// target.
i.watches[w.wd] = w
- targetWatches.Add(w)
+ ws.Add(w)
return w
}
@@ -312,7 +322,9 @@ func (i *Inotify) handleDeletion(w *Watch) {
// AddWatch constructs a new inotify watch and adds it to the target. It
// returns the watch descriptor returned by inotify_add_watch(2).
-func (i *Inotify) AddWatch(target *Dentry, mask uint32) int32 {
+//
+// The caller must hold a reference on target.
+func (i *Inotify) AddWatch(target *Dentry, mask uint32) (int32, error) {
// Note: Locking this inotify instance protects the result returned by
// Lookup() below. With the lock held, we know for sure the lookup result
// won't become stale because it's impossible for *this* instance to
@@ -320,8 +332,14 @@ func (i *Inotify) AddWatch(target *Dentry, mask uint32) int32 {
i.mu.Lock()
defer i.mu.Unlock()
+ ws := target.Watches()
+ if ws == nil {
+ // While Linux supports inotify watches on all filesystem types, watches on
+ // filesystems like kernfs are not generally useful, so we do not.
+ return 0, syserror.EPERM
+ }
// Does the target already have a watch from this inotify instance?
- if existing := target.Watches().Lookup(i.id); existing != nil {
+ if existing := ws.Lookup(i.id); existing != nil {
newmask := mask
if mask&linux.IN_MASK_ADD != 0 {
// "Add (OR) events to watch mask for this pathname if it already
@@ -329,12 +347,12 @@ func (i *Inotify) AddWatch(target *Dentry, mask uint32) int32 {
newmask |= atomic.LoadUint32(&existing.mask)
}
atomic.StoreUint32(&existing.mask, newmask)
- return existing.wd
+ return existing.wd, nil
}
// No existing watch, create a new watch.
- w := i.newWatchLocked(target, mask)
- return w.wd
+ w := i.newWatchLocked(target, ws, mask)
+ return w.wd, nil
}
// RmWatch looks up an inotify watch for the given 'wd' and configures the
@@ -353,9 +371,19 @@ func (i *Inotify) RmWatch(wd int32) error {
delete(i.watches, wd)
// Remove the watch from the watch target.
- w.set.Remove(w.OwnerID())
+ ws := w.target.Watches()
+ // AddWatch ensures that w.target has a non-nil watch set.
+ if ws == nil {
+ panic("Watched dentry cannot have nil watch set")
+ }
+ ws.Remove(w.OwnerID())
+ remaining := ws.Size()
i.mu.Unlock()
+ if remaining == 0 {
+ w.target.OnZeroWatches()
+ }
+
// Generate the event for the removal.
i.queueEvent(newEvent(wd, "", linux.IN_IGNORED, 0))
@@ -374,6 +402,13 @@ type Watches struct {
ws map[uint64]*Watch
}
+// Size returns the number of watches held by w.
+func (w *Watches) Size() int {
+ w.mu.Lock()
+ defer w.mu.Unlock()
+ return len(w.ws)
+}
+
// Lookup returns the watch owned by an inotify instance with the given id.
// Returns nil if no such watch exists.
//
@@ -459,10 +494,6 @@ func (w *Watches) NotifyWithExclusions(name string, events, cookie uint32, et Ev
func (w *Watches) HandleDeletion() {
w.Notify("", linux.IN_DELETE_SELF, 0, InodeEvent)
- // TODO(gvisor.dev/issue/1479): This doesn't work because maps are not copied
- // by value. Ideally, we wouldn't have this circular locking so we can just
- // notify of IN_DELETE_SELF in the same loop below.
- //
// We can't hold w.mu while calling watch.handleDeletion to preserve lock
// ordering w.r.t to the owner inotify instances. Instead, atomically move
// the watches map into a local variable so we can iterate over it safely.
@@ -495,9 +526,8 @@ type Watch struct {
// Descriptor for this watch. This is unique across an inotify instance.
wd int32
- // set is the watch set containing this watch. It belongs to the target file
- // of this watch.
- set *Watches
+ // target is a dentry representing the watch target. Its watch set contains this watch.
+ target *Dentry
// Events being monitored via this watch. Must be accessed with atomic
// memory operations.
@@ -606,7 +636,7 @@ func (e *Event) setName(name string) {
func (e *Event) sizeOf() int {
s := inotifyEventBaseSize + int(e.len)
if s < inotifyEventBaseSize {
- panic("overflow")
+ panic("Overflowed event size")
}
return s
}
@@ -676,11 +706,15 @@ func InotifyEventFromStatMask(mask uint32) uint32 {
}
// InotifyRemoveChild sends the appriopriate notifications to the watch sets of
-// the child being removed and its parent.
+// the child being removed and its parent. Note that unlike most pairs of
+// parent/child notifications, the child is notified first in this case.
func InotifyRemoveChild(self, parent *Watches, name string) {
- self.Notify("", linux.IN_ATTRIB, 0, InodeEvent)
- parent.Notify(name, linux.IN_DELETE, 0, InodeEvent)
- // TODO(gvisor.dev/issue/1479): implement IN_EXCL_UNLINK.
+ if self != nil {
+ self.Notify("", linux.IN_ATTRIB, 0, InodeEvent)
+ }
+ if parent != nil {
+ parent.Notify(name, linux.IN_DELETE, 0, InodeEvent)
+ }
}
// InotifyRename sends the appriopriate notifications to the watch sets of the
@@ -691,8 +725,14 @@ func InotifyRename(ctx context.Context, renamed, oldParent, newParent *Watches,
dirEv = linux.IN_ISDIR
}
cookie := uniqueid.InotifyCookie(ctx)
- oldParent.Notify(oldName, dirEv|linux.IN_MOVED_FROM, cookie, InodeEvent)
- newParent.Notify(newName, dirEv|linux.IN_MOVED_TO, cookie, InodeEvent)
+ if oldParent != nil {
+ oldParent.Notify(oldName, dirEv|linux.IN_MOVED_FROM, cookie, InodeEvent)
+ }
+ if newParent != nil {
+ newParent.Notify(newName, dirEv|linux.IN_MOVED_TO, cookie, InodeEvent)
+ }
// Somewhat surprisingly, self move events do not have a cookie.
- renamed.Notify("", linux.IN_MOVE_SELF, 0, InodeEvent)
+ if renamed != nil {
+ renamed.Notify("", linux.IN_MOVE_SELF, 0, InodeEvent)
+ }
}
diff --git a/pkg/sentry/vfs/vfs.go b/pkg/sentry/vfs/vfs.go
index 9acca8bc7..58c7ad778 100644
--- a/pkg/sentry/vfs/vfs.go
+++ b/pkg/sentry/vfs/vfs.go
@@ -24,6 +24,9 @@
// Locks acquired by FilesystemImpls between Prepare{Delete,Rename}Dentry and Commit{Delete,Rename*}Dentry
// VirtualFilesystem.filesystemsMu
// EpollInstance.mu
+// Inotify.mu
+// Watches.mu
+// Inotify.evMu
// VirtualFilesystem.fsTypesMu
//
// Locking Dentry.mu in multiple Dentries requires holding
diff --git a/test/syscalls/linux/BUILD b/test/syscalls/linux/BUILD
index 078e4a284..7282d675e 100644
--- a/test/syscalls/linux/BUILD
+++ b/test/syscalls/linux/BUILD
@@ -974,6 +974,7 @@ cc_binary(
"//test/util:thread_util",
"@com_google_absl//absl/strings",
"@com_google_absl//absl/strings:str_format",
+ "@com_google_absl//absl/synchronization",
"@com_google_absl//absl/time",
],
)
diff --git a/test/syscalls/linux/inotify.cc b/test/syscalls/linux/inotify.cc
index 1d1a7171d..13e096e9c 100644
--- a/test/syscalls/linux/inotify.cc
+++ b/test/syscalls/linux/inotify.cc
@@ -29,6 +29,7 @@
#include "absl/strings/str_cat.h"
#include "absl/strings/str_format.h"
#include "absl/strings/str_join.h"
+#include "absl/synchronization/mutex.h"
#include "absl/time/clock.h"
#include "absl/time/time.h"
#include "test/util/epoll_util.h"
@@ -1305,7 +1306,7 @@ TEST(Inotify, UtimesGeneratesAttribEvent) {
const int wd = ASSERT_NO_ERRNO_AND_VALUE(
InotifyAddWatch(fd.get(), root.path(), IN_ALL_EVENTS));
- struct timeval times[2] = {{1, 0}, {2, 0}};
+ const struct timeval times[2] = {{1, 0}, {2, 0}};
EXPECT_THAT(futimes(file1_fd.get(), times), SyscallSucceeds());
const std::vector<Event> events =
@@ -2018,7 +2019,7 @@ TEST(Inotify, ExcludeUnlinkInodeEvents_NoRandomSave) {
Event(IN_MODIFY, wd, Basename(file.path())),
}));
- struct timeval times[2] = {{1, 0}, {2, 0}};
+ const struct timeval times[2] = {{1, 0}, {2, 0}};
ASSERT_THAT(futimes(fd.get(), times), SyscallSucceeds());
events = ASSERT_NO_ERRNO_AND_VALUE(DrainEvents(inotify_fd.get()));
EXPECT_THAT(events, Are({Event(IN_ATTRIB, wd, Basename(file.path()))}));
@@ -2030,6 +2031,252 @@ TEST(Inotify, ExcludeUnlinkInodeEvents_NoRandomSave) {
EXPECT_THAT(events, Are({Event(IN_ATTRIB, wd, Basename(file.path()))}));
}
+// This test helps verify that the lock order of filesystem and inotify locks
+// is respected when inotify instances and watch targets are concurrently being
+// destroyed.
+TEST(InotifyTest, InotifyAndTargetDestructionDoNotDeadlock_NoRandomSave) {
+ const DisableSave ds; // Too many syscalls.
+
+ // A file descriptor protected by a mutex. This ensures that while a
+ // descriptor is in use, it cannot be closed and reused for a different file
+ // description.
+ struct atomic_fd {
+ int fd;
+ absl::Mutex mu;
+ };
+
+ // Set up initial inotify instances.
+ constexpr int num_fds = 3;
+ std::vector<atomic_fd> fds(num_fds);
+ for (int i = 0; i < num_fds; i++) {
+ int fd;
+ ASSERT_THAT(fd = inotify_init1(IN_NONBLOCK), SyscallSucceeds());
+ fds[i].fd = fd;
+ }
+
+ // Set up initial watch targets.
+ std::vector<std::string> paths;
+ for (int i = 0; i < 3; i++) {
+ paths.push_back(NewTempAbsPath());
+ ASSERT_THAT(mknod(paths[i].c_str(), S_IFREG | 0600, 0), SyscallSucceeds());
+ }
+
+ constexpr absl::Duration runtime = absl::Seconds(4);
+
+ // Constantly replace each inotify instance with a new one.
+ auto replace_fds = [&] {
+ for (auto start = absl::Now(); absl::Now() - start < runtime;) {
+ for (auto& afd : fds) {
+ int new_fd;
+ ASSERT_THAT(new_fd = inotify_init1(IN_NONBLOCK), SyscallSucceeds());
+ absl::MutexLock l(&afd.mu);
+ ASSERT_THAT(close(afd.fd), SyscallSucceeds());
+ afd.fd = new_fd;
+ for (auto& p : paths) {
+ // inotify_add_watch may fail if the file at p was deleted.
+ ASSERT_THAT(inotify_add_watch(afd.fd, p.c_str(), IN_ALL_EVENTS),
+ AnyOf(SyscallSucceeds(), SyscallFailsWithErrno(ENOENT)));
+ }
+ }
+ sched_yield();
+ }
+ };
+
+ std::list<ScopedThread> ts;
+ for (int i = 0; i < 3; i++) {
+ ts.emplace_back(replace_fds);
+ }
+
+ // Constantly replace each watch target with a new one.
+ for (auto start = absl::Now(); absl::Now() - start < runtime;) {
+ for (auto& p : paths) {
+ ASSERT_THAT(unlink(p.c_str()), SyscallSucceeds());
+ ASSERT_THAT(mknod(p.c_str(), S_IFREG | 0600, 0), SyscallSucceeds());
+ }
+ sched_yield();
+ }
+}
+
+// This test helps verify that the lock order of filesystem and inotify locks
+// is respected when adding/removing watches occurs concurrently with the
+// removal of their targets.
+TEST(InotifyTest, AddRemoveUnlinkDoNotDeadlock_NoRandomSave) {
+ const DisableSave ds; // Too many syscalls.
+
+ // Set up inotify instances.
+ constexpr int num_fds = 3;
+ std::vector<int> fds(num_fds);
+ for (int i = 0; i < num_fds; i++) {
+ ASSERT_THAT(fds[i] = inotify_init1(IN_NONBLOCK), SyscallSucceeds());
+ }
+
+ // Set up initial watch targets.
+ std::vector<std::string> paths;
+ for (int i = 0; i < 3; i++) {
+ paths.push_back(NewTempAbsPath());
+ ASSERT_THAT(mknod(paths[i].c_str(), S_IFREG | 0600, 0), SyscallSucceeds());
+ }
+
+ constexpr absl::Duration runtime = absl::Seconds(1);
+
+ // Constantly add/remove watches for each inotify instance/watch target pair.
+ auto add_remove_watches = [&] {
+ for (auto start = absl::Now(); absl::Now() - start < runtime;) {
+ for (int fd : fds) {
+ for (auto& p : paths) {
+ // Do not assert on inotify_add_watch and inotify_rm_watch. They may
+ // fail if the file at p was deleted. inotify_add_watch may also fail
+ // if another thread beat us to adding a watch.
+ const int wd = inotify_add_watch(fd, p.c_str(), IN_ALL_EVENTS);
+ if (wd > 0) {
+ inotify_rm_watch(fd, wd);
+ }
+ }
+ }
+ sched_yield();
+ }
+ };
+
+ std::list<ScopedThread> ts;
+ for (int i = 0; i < 15; i++) {
+ ts.emplace_back(add_remove_watches);
+ }
+
+ // Constantly replace each watch target with a new one.
+ for (auto start = absl::Now(); absl::Now() - start < runtime;) {
+ for (auto& p : paths) {
+ ASSERT_THAT(unlink(p.c_str()), SyscallSucceeds());
+ ASSERT_THAT(mknod(p.c_str(), S_IFREG | 0600, 0), SyscallSucceeds());
+ }
+ sched_yield();
+ }
+}
+
+// This test helps verify that the lock order of filesystem and inotify locks
+// is respected when many inotify events and filesystem operations occur
+// simultaneously.
+TEST(InotifyTest, NotifyNoDeadlock_NoRandomSave) {
+ const DisableSave ds; // Too many syscalls.
+
+ const TempPath parent = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir());
+ const std::string dir = parent.path();
+
+ // mu protects file, which will change on rename.
+ absl::Mutex mu;
+ std::string file = NewTempAbsPathInDir(dir);
+ ASSERT_THAT(mknod(file.c_str(), 0644 | S_IFREG, 0), SyscallSucceeds());
+
+ const absl::Duration runtime = absl::Milliseconds(300);
+
+ // Add/remove watches on dir and file.
+ ScopedThread add_remove_watches([&] {
+ const FileDescriptor ifd =
+ ASSERT_NO_ERRNO_AND_VALUE(InotifyInit1(IN_NONBLOCK));
+ int dir_wd = ASSERT_NO_ERRNO_AND_VALUE(
+ InotifyAddWatch(ifd.get(), dir, IN_ALL_EVENTS));
+ int file_wd;
+ {
+ absl::ReaderMutexLock l(&mu);
+ file_wd = ASSERT_NO_ERRNO_AND_VALUE(
+ InotifyAddWatch(ifd.get(), file, IN_ALL_EVENTS));
+ }
+ for (auto start = absl::Now(); absl::Now() - start < runtime;) {
+ ASSERT_THAT(inotify_rm_watch(ifd.get(), file_wd), SyscallSucceeds());
+ ASSERT_THAT(inotify_rm_watch(ifd.get(), dir_wd), SyscallSucceeds());
+ dir_wd = ASSERT_NO_ERRNO_AND_VALUE(
+ InotifyAddWatch(ifd.get(), dir, IN_ALL_EVENTS));
+ {
+ absl::ReaderMutexLock l(&mu);
+ file_wd = ASSERT_NO_ERRNO_AND_VALUE(
+ InotifyAddWatch(ifd.get(), file, IN_ALL_EVENTS));
+ }
+ sched_yield();
+ }
+ });
+
+ // Modify attributes on dir and file.
+ ScopedThread stats([&] {
+ int fd, dir_fd;
+ {
+ absl::ReaderMutexLock l(&mu);
+ ASSERT_THAT(fd = open(file.c_str(), O_RDONLY), SyscallSucceeds());
+ }
+ ASSERT_THAT(dir_fd = open(dir.c_str(), O_RDONLY | O_DIRECTORY),
+ SyscallSucceeds());
+ const struct timeval times[2] = {{1, 0}, {2, 0}};
+
+ for (auto start = absl::Now(); absl::Now() - start < runtime;) {
+ {
+ absl::ReaderMutexLock l(&mu);
+ EXPECT_THAT(utimes(file.c_str(), times), SyscallSucceeds());
+ }
+ EXPECT_THAT(futimes(fd, times), SyscallSucceeds());
+ EXPECT_THAT(utimes(dir.c_str(), times), SyscallSucceeds());
+ EXPECT_THAT(futimes(dir_fd, times), SyscallSucceeds());
+ sched_yield();
+ }
+ });
+
+ // Modify extended attributes on dir and file.
+ ScopedThread xattrs([&] {
+ // TODO(gvisor.dev/issue/1636): Support extended attributes in runsc gofer.
+ if (!IsRunningOnGvisor()) {
+ int fd;
+ {
+ absl::ReaderMutexLock l(&mu);
+ ASSERT_THAT(fd = open(file.c_str(), O_RDONLY), SyscallSucceeds());
+ }
+
+ const char* name = "user.test";
+ int val = 123;
+ for (auto start = absl::Now(); absl::Now() - start < runtime;) {
+ {
+ absl::ReaderMutexLock l(&mu);
+ ASSERT_THAT(
+ setxattr(file.c_str(), name, &val, sizeof(val), /*flags=*/0),
+ SyscallSucceeds());
+ ASSERT_THAT(removexattr(file.c_str(), name), SyscallSucceeds());
+ }
+
+ ASSERT_THAT(fsetxattr(fd, name, &val, sizeof(val), /*flags=*/0),
+ SyscallSucceeds());
+ ASSERT_THAT(fremovexattr(fd, name), SyscallSucceeds());
+ sched_yield();
+ }
+ }
+ });
+
+ // Read and write file's contents. Read and write dir's entries.
+ ScopedThread read_write([&] {
+ int fd;
+ {
+ absl::ReaderMutexLock l(&mu);
+ ASSERT_THAT(fd = open(file.c_str(), O_RDWR), SyscallSucceeds());
+ }
+ for (auto start = absl::Now(); absl::Now() - start < runtime;) {
+ int val = 123;
+ ASSERT_THAT(write(fd, &val, sizeof(val)), SyscallSucceeds());
+ ASSERT_THAT(read(fd, &val, sizeof(val)), SyscallSucceeds());
+ TempPath new_file =
+ ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileIn(dir));
+ ASSERT_NO_ERRNO(ListDir(dir, false));
+ new_file.reset();
+ sched_yield();
+ }
+ });
+
+ // Rename file.
+ for (auto start = absl::Now(); absl::Now() - start < runtime;) {
+ const std::string new_path = NewTempAbsPathInDir(dir);
+ {
+ absl::WriterMutexLock l(&mu);
+ ASSERT_THAT(rename(file.c_str(), new_path.c_str()), SyscallSucceeds());
+ file = new_path;
+ }
+ sched_yield();
+ }
+}
+
} // namespace
} // namespace testing
} // namespace gvisor