diff options
Diffstat (limited to 'pkg/sentry/fsimpl/gofer/gofer.go')
| -rw-r--r-- | pkg/sentry/fsimpl/gofer/gofer.go | 73 |
1 files changed, 63 insertions, 10 deletions
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. |