github.com/SagerNet/gvisor@v0.0.0-20210707092255-7731c139d75c/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  	"sync/atomic"
    19  
    20  	"github.com/SagerNet/gvisor/pkg/sentry/vfs"
    21  )
    22  
    23  func dentryTimestampFromP9(s, ns uint64) int64 {
    24  	return int64(s*1e9 + ns)
    25  }
    26  
    27  // Preconditions: d.cachedMetadataAuthoritative() == true.
    28  func (d *dentry) touchAtime(mnt *vfs.Mount) {
    29  	if mnt.Flags.NoATime || mnt.ReadOnly() {
    30  		return
    31  	}
    32  	if err := mnt.CheckBeginWrite(); err != nil {
    33  		return
    34  	}
    35  	now := d.fs.clock.Now().Nanoseconds()
    36  	d.metadataMu.Lock()
    37  	atomic.StoreInt64(&d.atime, now)
    38  	atomic.StoreUint32(&d.atimeDirty, 1)
    39  	d.metadataMu.Unlock()
    40  	mnt.EndWrite()
    41  }
    42  
    43  // Preconditions: d.metadataMu is locked. d.cachedMetadataAuthoritative() == true.
    44  func (d *dentry) touchAtimeLocked(mnt *vfs.Mount) {
    45  	if mnt.Flags.NoATime || mnt.ReadOnly() {
    46  		return
    47  	}
    48  	if err := mnt.CheckBeginWrite(); err != nil {
    49  		return
    50  	}
    51  	now := d.fs.clock.Now().Nanoseconds()
    52  	atomic.StoreInt64(&d.atime, now)
    53  	atomic.StoreUint32(&d.atimeDirty, 1)
    54  	mnt.EndWrite()
    55  }
    56  
    57  // Preconditions:
    58  // * d.cachedMetadataAuthoritative() == true.
    59  // * The caller has successfully called vfs.Mount.CheckBeginWrite().
    60  func (d *dentry) touchCtime() {
    61  	now := d.fs.clock.Now().Nanoseconds()
    62  	d.metadataMu.Lock()
    63  	atomic.StoreInt64(&d.ctime, now)
    64  	d.metadataMu.Unlock()
    65  }
    66  
    67  // Preconditions:
    68  // * d.cachedMetadataAuthoritative() == true.
    69  // * The caller has successfully called vfs.Mount.CheckBeginWrite().
    70  func (d *dentry) touchCMtime() {
    71  	now := d.fs.clock.Now().Nanoseconds()
    72  	d.metadataMu.Lock()
    73  	atomic.StoreInt64(&d.mtime, now)
    74  	atomic.StoreInt64(&d.ctime, now)
    75  	atomic.StoreUint32(&d.mtimeDirty, 1)
    76  	d.metadataMu.Unlock()
    77  }
    78  
    79  // Preconditions:
    80  // * d.cachedMetadataAuthoritative() == true.
    81  // * The caller has locked d.metadataMu.
    82  func (d *dentry) touchCMtimeLocked() {
    83  	now := d.fs.clock.Now().Nanoseconds()
    84  	atomic.StoreInt64(&d.mtime, now)
    85  	atomic.StoreInt64(&d.ctime, now)
    86  	atomic.StoreUint32(&d.mtimeDirty, 1)
    87  }