github.com/MerlinKodo/gvisor@v0.0.0-20231110090155-957f62ecf90e/pkg/sentry/fsimpl/gofer/time.go (about)

     1  // Copyright 2019 The gVisor Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package gofer
    16  
    17  import (
    18  	"golang.org/x/sys/unix"
    19  	"github.com/MerlinKodo/gvisor/pkg/abi/linux"
    20  	"github.com/MerlinKodo/gvisor/pkg/sentry/vfs"
    21  )
    22  
    23  func dentryTimestamp(t linux.StatxTimestamp) int64 {
    24  	return t.ToNsec()
    25  }
    26  
    27  func dentryTimestampFromUnix(t unix.Timespec) int64 {
    28  	return dentryTimestamp(linux.StatxTimestamp{Sec: t.Sec, Nsec: uint32(t.Nsec)})
    29  }
    30  
    31  // Preconditions: d.cachedMetadataAuthoritative() == true.
    32  func (d *dentry) touchAtime(mnt *vfs.Mount) {
    33  	if mnt.Flags.NoATime || mnt.ReadOnly() {
    34  		return
    35  	}
    36  	if err := mnt.CheckBeginWrite(); err != nil {
    37  		return
    38  	}
    39  	now := d.fs.clock.Now().Nanoseconds()
    40  	d.metadataMu.Lock()
    41  	d.atime.Store(now)
    42  	d.atimeDirty.Store(1)
    43  	d.metadataMu.Unlock()
    44  	mnt.EndWrite()
    45  }
    46  
    47  // Preconditions: d.metadataMu is locked. d.cachedMetadataAuthoritative() == true.
    48  func (d *dentry) touchAtimeLocked(mnt *vfs.Mount) {
    49  	if mnt.Flags.NoATime || mnt.ReadOnly() {
    50  		return
    51  	}
    52  	if err := mnt.CheckBeginWrite(); err != nil {
    53  		return
    54  	}
    55  	now := d.fs.clock.Now().Nanoseconds()
    56  	d.atime.Store(now)
    57  	d.atimeDirty.Store(1)
    58  	mnt.EndWrite()
    59  }
    60  
    61  // Preconditions:
    62  //   - d.cachedMetadataAuthoritative() == true.
    63  //   - The caller has successfully called vfs.Mount.CheckBeginWrite().
    64  func (d *dentry) touchCtime() {
    65  	now := d.fs.clock.Now().Nanoseconds()
    66  	d.metadataMu.Lock()
    67  	d.ctime.Store(now)
    68  	d.metadataMu.Unlock()
    69  }
    70  
    71  // Preconditions:
    72  //   - d.cachedMetadataAuthoritative() == true.
    73  //   - The caller has successfully called vfs.Mount.CheckBeginWrite().
    74  func (d *dentry) touchCMtime() {
    75  	now := d.fs.clock.Now().Nanoseconds()
    76  	d.metadataMu.Lock()
    77  	d.mtime.Store(now)
    78  	d.ctime.Store(now)
    79  	d.mtimeDirty.Store(1)
    80  	d.metadataMu.Unlock()
    81  }
    82  
    83  // Preconditions:
    84  //   - d.cachedMetadataAuthoritative() == true.
    85  //   - The caller has locked d.metadataMu.
    86  func (d *dentry) touchCMtimeLocked() {
    87  	now := d.fs.clock.Now().Nanoseconds()
    88  	d.mtime.Store(now)
    89  	d.ctime.Store(now)
    90  	d.mtimeDirty.Store(1)
    91  }