From e0614367ca27c2e47649e08291e0f1d19d42232e Mon Sep 17 00:00:00 2001 From: Kir Kolyshkin Date: Tue, 31 Mar 2020 01:59:44 -0700 Subject: pkg/spec.InitFSMounts: optimize Instead of getting mount options from /proc/self/mountinfo, which is very costly to read/parse (and can even be unreliable), let's use statfs(2) to figure out the flags we need. [v2: move getting default options to pkg/util, make it linux-specific] Signed-off-by: Kir Kolyshkin --- pkg/spec/storage.go | 60 ++++----------------------------------------- pkg/util/mountOpts.go | 24 +++++++++--------- pkg/util/mountOpts_linux.go | 23 +++++++++++++++++ pkg/util/mountOpts_other.go | 7 ++++++ 4 files changed, 48 insertions(+), 66 deletions(-) create mode 100644 pkg/util/mountOpts_linux.go create mode 100644 pkg/util/mountOpts_other.go (limited to 'pkg') diff --git a/pkg/spec/storage.go b/pkg/spec/storage.go index 335907d12..68a84d638 100644 --- a/pkg/spec/storage.go +++ b/pkg/spec/storage.go @@ -10,7 +10,6 @@ import ( "github.com/containers/buildah/pkg/parse" "github.com/containers/libpod/libpod" "github.com/containers/libpod/pkg/util" - pmount "github.com/containers/storage/pkg/mount" spec "github.com/opencontainers/runtime-spec/specs-go" "github.com/pkg/errors" "github.com/sirupsen/logrus" @@ -856,44 +855,16 @@ func SupercedeUserMounts(mounts []spec.Mount, configMount []spec.Mount) []spec.M // Ensure mount options on all mounts are correct func InitFSMounts(mounts []spec.Mount) error { - // We need to look up mounts so we can figure out the proper mount flags - // to apply. - systemMounts, err := pmount.GetMounts() - if err != nil { - return errors.Wrapf(err, "error retrieving system mounts to look up mount options") - } - for i, m := range mounts { - if m.Type == TypeBind { - baseMnt, err := findMount(m.Source, systemMounts) - if err != nil { - return errors.Wrapf(err, "error looking up mountpoint for mount %s", m.Source) - } - var noexec, nosuid, nodev bool - for _, baseOpt := range strings.Split(baseMnt.Opts, ",") { - switch baseOpt { - case "noexec": - noexec = true - case "nosuid": - nosuid = true - case "nodev": - nodev = true - } - } - - defaultMountOpts := new(util.DefaultMountOptions) - defaultMountOpts.Noexec = noexec - defaultMountOpts.Nosuid = nosuid - defaultMountOpts.Nodev = nodev - - opts, err := util.ProcessOptions(m.Options, false, defaultMountOpts) + switch { + case m.Type == TypeBind: + opts, err := util.ProcessOptions(m.Options, false, m.Source) if err != nil { return err } mounts[i].Options = opts - } - if m.Type == TypeTmpfs && filepath.Clean(m.Destination) != "/dev" { - opts, err := util.ProcessOptions(m.Options, true, nil) + case m.Type == TypeTmpfs && filepath.Clean(m.Destination) != "/dev": + opts, err := util.ProcessOptions(m.Options, true, "") if err != nil { return err } @@ -902,24 +873,3 @@ func InitFSMounts(mounts []spec.Mount) error { } return nil } - -// TODO: We could make this a bit faster by building a tree of the mountpoints -// and traversing it to identify the correct mount. -func findMount(target string, mounts []*pmount.Info) (*pmount.Info, error) { - var err error - target, err = filepath.Abs(target) - if err != nil { - return nil, errors.Wrapf(err, "cannot resolve %s", target) - } - var bestSoFar *pmount.Info - for _, i := range mounts { - if bestSoFar != nil && len(bestSoFar.Mountpoint) > len(i.Mountpoint) { - // Won't be better than what we have already found - continue - } - if strings.HasPrefix(target, i.Mountpoint) { - bestSoFar = i - } - } - return bestSoFar, nil -} diff --git a/pkg/util/mountOpts.go b/pkg/util/mountOpts.go index d21800bc3..329a7c913 100644 --- a/pkg/util/mountOpts.go +++ b/pkg/util/mountOpts.go @@ -13,19 +13,17 @@ var ( ErrDupeMntOption = errors.Errorf("duplicate mount option passed") ) -// DefaultMountOptions sets default mount options for ProcessOptions. -type DefaultMountOptions struct { - Noexec bool - Nosuid bool - Nodev bool +type defaultMountOptions struct { + noexec bool + nosuid bool + nodev bool } // ProcessOptions parses the options for a bind or tmpfs mount and ensures that // they are sensible and follow convention. The isTmpfs variable controls // whether extra, tmpfs-specific options will be allowed. -// The defaults variable controls default mount options that will be set. If it -// is not included, they will be set unconditionally. -func ProcessOptions(options []string, isTmpfs bool, defaults *DefaultMountOptions) ([]string, error) { +// The sourcePath variable, if not empty, contains a bind mount source. +func ProcessOptions(options []string, isTmpfs bool, sourcePath string) ([]string, error) { var ( foundWrite, foundSize, foundProp, foundMode, foundExec, foundSuid, foundDev, foundCopyUp, foundBind, foundZ bool ) @@ -122,13 +120,17 @@ func ProcessOptions(options []string, isTmpfs bool, defaults *DefaultMountOption if !foundProp { newOptions = append(newOptions, "rprivate") } - if !foundExec && (defaults == nil || defaults.Noexec) { + defaults, err := getDefaultMountOptions(sourcePath) + if err != nil { + return nil, err + } + if !foundExec && defaults.noexec { newOptions = append(newOptions, "noexec") } - if !foundSuid && (defaults == nil || defaults.Nosuid) { + if !foundSuid && defaults.nosuid { newOptions = append(newOptions, "nosuid") } - if !foundDev && (defaults == nil || defaults.Nodev) { + if !foundDev && defaults.nodev { newOptions = append(newOptions, "nodev") } if isTmpfs && !foundCopyUp { diff --git a/pkg/util/mountOpts_linux.go b/pkg/util/mountOpts_linux.go new file mode 100644 index 000000000..3eac4dd25 --- /dev/null +++ b/pkg/util/mountOpts_linux.go @@ -0,0 +1,23 @@ +package util + +import ( + "os" + + "golang.org/x/sys/unix" +) + +func getDefaultMountOptions(path string) (defaultMountOptions, error) { + opts := defaultMountOptions{true, true, true} + if path == "" { + return opts, nil + } + var statfs unix.Statfs_t + if e := unix.Statfs(path, &statfs); e != nil { + return opts, &os.PathError{Op: "statfs", Path: path, Err: e} + } + opts.nodev = (statfs.Flags&unix.MS_NODEV == unix.MS_NODEV) + opts.noexec = (statfs.Flags&unix.MS_NOEXEC == unix.MS_NOEXEC) + opts.nosuid = (statfs.Flags&unix.MS_NOSUID == unix.MS_NOSUID) + + return opts, nil +} diff --git a/pkg/util/mountOpts_other.go b/pkg/util/mountOpts_other.go new file mode 100644 index 000000000..6a34942e5 --- /dev/null +++ b/pkg/util/mountOpts_other.go @@ -0,0 +1,7 @@ +// +build !linux + +package util + +func getDefaultMountOptions(path string) (opts defaultMountOptions, err error) { + return +} -- cgit v1.2.3-54-g00ecf