diff --git a/daemon/graphdriver/projectquota.go b/daemon/graphdriver/projectquota.go new file mode 100644 index 0000000000..82ee5011c4 --- /dev/null +++ b/daemon/graphdriver/projectquota.go @@ -0,0 +1,324 @@ +// +build linux + +// +// projectquota.go - implements XFS project quota controls +// for setting quota limits on a newly created directory. +// It currently supports the legacy XFS specific ioctls. +// +// TODO: use generic quota control ioctl FS_IOC_FS{GET,SET}XATTR +// for both xfs/ext4 for kernel version >= v4.5 +// + +package graphdriver + +/* +#include +#include +#include +#include +#include +struct fsxattr { + __u32 fsx_xflags; + __u32 fsx_extsize; + __u32 fsx_nextents; + __u32 fsx_projid; + unsigned char fsx_pad[12]; +}; +#define FS_XFLAG_PROJINHERIT 0x00000200 +#define FS_IOC_FSGETXATTR _IOR ('X', 31, struct fsxattr) +#define FS_IOC_FSSETXATTR _IOW ('X', 32, struct fsxattr) + +#define PRJQUOTA 2 +#define XFS_PROJ_QUOTA 2 +#define Q_XSETPQLIM QCMD(Q_XSETQLIM, PRJQUOTA) +#define Q_XGETPQUOTA QCMD(Q_XGETQUOTA, PRJQUOTA) +*/ +import "C" +import ( + "fmt" + "io/ioutil" + "os" + "path" + "path/filepath" + "syscall" + "unsafe" + + "github.com/Sirupsen/logrus" +) + +// Quota limit params - currently we only control blocks hard limit +type Quota struct { + Size uint64 +} + +// QuotaCtl - Context to be used by storage driver (e.g. overlay) +// who wants to apply project quotas to container dirs +type QuotaCtl struct { + backingFsBlockDev string + nextProjectID uint32 + quotas map[string]uint32 +} + +// NewQuotaCtl - initialize project quota support. +// Test to make sure that quota can be set on a test dir and find +// the first project id to be used for the next container create. +// +// Returns nil (and error) if project quota is not supported. +// +// First get the project id of the home directory. +// This test will fail if the backing fs is not xfs. +// +// xfs_quota tool can be used to assign a project id to the driver home directory, e.g.: +// echo 999:/var/lib/docker/overlay2 >> /etc/projects +// echo docker:999 >> /etc/projid +// xfs_quota -x -c 'project -s docker' / +// +// In that case, the home directory project id will be used as a "start offset" +// and all containers will be assigned larger project ids (e.g. >= 1000). +// This is a way to prevent xfs_quota management from conflicting with docker. +// +// Then try to create a test directory with the next project id and set a quota +// on it. If that works, continue to scan existing containers to map allocated +// project ids. +// +func NewQuotaCtl(basePath string) (*QuotaCtl, error) { + // + // Get project id of parent dir as minimal id to be used by driver + // + minProjectID, err := getProjectID(basePath) + if err != nil { + return nil, err + } + minProjectID++ + + // + // create backing filesystem device node + // + backingFsBlockDev, err := makeBackingFsDev(basePath) + if err != nil { + return nil, err + } + + // + // Test if filesystem supports project quotas by trying to set + // a quota on the first available project id + // + quota := Quota{ + Size: 0, + } + if err := setProjectQuota(backingFsBlockDev, minProjectID, quota); err != nil { + return nil, err + } + + q := QuotaCtl{ + backingFsBlockDev: backingFsBlockDev, + nextProjectID: minProjectID + 1, + quotas: make(map[string]uint32), + } + + // + // get first project id to be used for next container + // + err = q.findNextProjectID(basePath) + if err != nil { + return nil, err + } + + logrus.Debugf("NewQuotaCtl(%s): nextProjectID = %d", basePath, q.nextProjectID) + return &q, nil +} + +// SetQuota - assign a unique project id to directory and set the quota limits +// for that project id +func (q *QuotaCtl) SetQuota(targetPath string, quota Quota) error { + + projectID, ok := q.quotas[targetPath] + if !ok { + projectID = q.nextProjectID + + // + // assign project id to new container directory + // + err := setProjectID(targetPath, projectID) + if err != nil { + return err + } + + q.quotas[targetPath] = projectID + q.nextProjectID++ + } + + // + // set the quota limit for the container's project id + // + logrus.Debugf("SetQuota(%s, %d): projectID=%d", targetPath, quota.Size, projectID) + return setProjectQuota(q.backingFsBlockDev, projectID, quota) +} + +// setProjectQuota - set the quota for project id on xfs block device +func setProjectQuota(backingFsBlockDev string, projectID uint32, quota Quota) error { + var d C.fs_disk_quota_t + d.d_version = C.FS_DQUOT_VERSION + d.d_id = C.__u32(projectID) + d.d_flags = C.XFS_PROJ_QUOTA + + d.d_fieldmask = C.FS_DQ_BHARD | C.FS_DQ_BSOFT + d.d_blk_hardlimit = C.__u64(quota.Size / 512) + d.d_blk_softlimit = d.d_blk_hardlimit + + var cs = C.CString(backingFsBlockDev) + defer C.free(unsafe.Pointer(cs)) + + _, _, errno := syscall.Syscall6(syscall.SYS_QUOTACTL, C.Q_XSETPQLIM, + uintptr(unsafe.Pointer(cs)), uintptr(d.d_id), + uintptr(unsafe.Pointer(&d)), 0, 0) + if errno != 0 { + return fmt.Errorf("Failed to set quota limit for projid %d on %s: %v", + projectID, backingFsBlockDev, errno.Error()) + } + + return nil +} + +// GetQuota - get the quota limits of a directory that was configured with SetQuota +func (q *QuotaCtl) GetQuota(targetPath string, quota *Quota) error { + + projectID, ok := q.quotas[targetPath] + if !ok { + return fmt.Errorf("quota not found for path : %s", targetPath) + } + + // + // get the quota limit for the container's project id + // + var d C.fs_disk_quota_t + + var cs = C.CString(q.backingFsBlockDev) + defer C.free(unsafe.Pointer(cs)) + + _, _, errno := syscall.Syscall6(syscall.SYS_QUOTACTL, C.Q_XGETPQUOTA, + uintptr(unsafe.Pointer(cs)), uintptr(C.__u32(projectID)), + uintptr(unsafe.Pointer(&d)), 0, 0) + if errno != 0 { + return fmt.Errorf("Failed to get quota limit for projid %d on %s: %v", + projectID, q.backingFsBlockDev, errno.Error()) + } + quota.Size = uint64(d.d_blk_hardlimit) * 512 + + return nil +} + +// getProjectID - get the project id of path on xfs +func getProjectID(targetPath string) (uint32, error) { + dir, err := openDir(targetPath) + if err != nil { + return 0, err + } + defer closeDir(dir) + + var fsx C.struct_fsxattr + _, _, errno := syscall.Syscall(syscall.SYS_IOCTL, getDirFd(dir), C.FS_IOC_FSGETXATTR, + uintptr(unsafe.Pointer(&fsx))) + if errno != 0 { + return 0, fmt.Errorf("Failed to get projid for %s: %v", targetPath, errno.Error()) + } + + return uint32(fsx.fsx_projid), nil +} + +// setProjectID - set the project id of path on xfs +func setProjectID(targetPath string, projectID uint32) error { + dir, err := openDir(targetPath) + if err != nil { + return err + } + defer closeDir(dir) + + var fsx C.struct_fsxattr + _, _, errno := syscall.Syscall(syscall.SYS_IOCTL, getDirFd(dir), C.FS_IOC_FSGETXATTR, + uintptr(unsafe.Pointer(&fsx))) + if errno != 0 { + return fmt.Errorf("Failed to get projid for %s: %v", targetPath, errno.Error()) + } + fsx.fsx_projid = C.__u32(projectID) + fsx.fsx_xflags |= C.FS_XFLAG_PROJINHERIT + _, _, errno = syscall.Syscall(syscall.SYS_IOCTL, getDirFd(dir), C.FS_IOC_FSSETXATTR, + uintptr(unsafe.Pointer(&fsx))) + if errno != 0 { + return fmt.Errorf("Failed to set projid for %s: %v", targetPath, errno.Error()) + } + + return nil +} + +// findNextProjectID - find the next project id to be used for containers +// by scanning driver home directory to find used project ids +func (q *QuotaCtl) findNextProjectID(home string) error { + files, err := ioutil.ReadDir(home) + if err != nil { + return fmt.Errorf("read directory failed : %s", home) + } + for _, file := range files { + if !file.IsDir() { + continue + } + path := filepath.Join(home, file.Name()) + projid, err := getProjectID(path) + if err != nil { + return err + } + if projid > 0 { + q.quotas[path] = projid + } + if q.nextProjectID <= projid { + q.nextProjectID = projid + 1 + } + } + + return nil +} + +func free(p *C.char) { + C.free(unsafe.Pointer(p)) +} + +func openDir(path string) (*C.DIR, error) { + Cpath := C.CString(path) + defer free(Cpath) + + dir := C.opendir(Cpath) + if dir == nil { + return nil, fmt.Errorf("Can't open dir") + } + return dir, nil +} + +func closeDir(dir *C.DIR) { + if dir != nil { + C.closedir(dir) + } +} + +func getDirFd(dir *C.DIR) uintptr { + return uintptr(C.dirfd(dir)) +} + +// Get the backing block device of the driver home directory +// and create a block device node under the home directory +// to be used by quotactl commands +func makeBackingFsDev(home string) (string, error) { + fileinfo, err := os.Stat(home) + if err != nil { + return "", err + } + + backingFsBlockDev := path.Join(home, "backingFsBlockDev") + // Re-create just in case comeone copied the home directory over to a new device + syscall.Unlink(backingFsBlockDev) + stat := fileinfo.Sys().(*syscall.Stat_t) + if err := syscall.Mknod(backingFsBlockDev, syscall.S_IFBLK|0600, int(stat.Dev)); err != nil { + return "", fmt.Errorf("Failed to mknod %s: %v", backingFsBlockDev, err) + } + + return backingFsBlockDev, nil +}