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all: Support syncing extended attributes (fixes #2698) (#8513)

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This adds support for syncing extended attributes on supported
filesystem on Linux, macOS, FreeBSD and NetBSD. Windows is currently
excluded because the APIs seem onerous and annoying and frankly the uses
cases seem few and far between. On Unixes this also covers ACLs as those
are stored as extended attributes.

Similar to ownership syncing this will optional & opt-in, which two
settings controlling the main behavior: one to "sync" xattrs (read &
write) and another one to "scan" xattrs (only read them so other devices
can "sync" them, but not apply any locally).

Co-authored-by: Tomasz Wilczyński <twilczynski@naver.com>
This commit is contained in:
Jakob Borg
2022-09-14 09:50:55 +02:00
committed by GitHub
co-authored by Tomasz Wilczyński
parent 8065cf7e97
commit 6cac308bcd
37 changed files with 2720 additions and 527 deletions
Download Patch File Download Diff File Expand all files Collapse all files
lib/model/folder_sendrecv.go
+64 -19
View File
@@ -592,8 +592,7 @@ func (f *sendReceiveFolder) handleDir(file protocol.FileInfo, snap *db.Snapshot,
// Check that it is what we have in the database.
curFile, hasCurFile := snap.Get(protocol.LocalDeviceID, file.Name)
if err := f.scanIfItemChanged(file.Name, info, curFile, hasCurFile, scanChan); err != nil {
err = fmt.Errorf("handling dir: %w", err)
f.newPullError(file.Name, err)
f.newPullError(file.Name, fmt.Errorf("handling dir: %w", err))
return
}
@@ -661,7 +660,7 @@ func (f *sendReceiveFolder) handleDir(file protocol.FileInfo, snap *db.Snapshot,
// It's OK to change mode bits on stuff within non-writable directories.
if !f.IgnorePerms && !file.NoPermissions {
if err := f.mtimefs.Chmod(file.Name, mode|(info.Mode()&retainBits)); err != nil {
f.newPullError(file.Name, err)
f.newPullError(file.Name, fmt.Errorf("handling dir (setting permissions): %w", err))
return
}
}
@@ -988,13 +987,14 @@ func (f *sendReceiveFolder) renameFile(cur, source, target protocol.FileInfo, sn
err = errModified
default:
var fi protocol.FileInfo
if fi, err = scanner.CreateFileInfo(stat, target.Name, f.mtimefs, f.SyncOwnership); err == nil {
if fi, err = scanner.CreateFileInfo(stat, target.Name, f.mtimefs, f.SyncOwnership, f.SyncXattrs, f.XattrFilter); err == nil {
if !fi.IsEquivalentOptional(curTarget, protocol.FileInfoComparison{
ModTimeWindow: f.modTimeWindow,
IgnorePerms: f.IgnorePerms,
IgnoreBlocks: true,
IgnoreFlags: protocol.LocalAllFlags,
IgnoreOwnership: !f.SyncOwnership,
IgnoreXattrs: !f.SyncXattrs,
}) {
// Target changed
scanChan <- target.Name
@@ -1203,8 +1203,8 @@ func populateOffsets(blocks []protocol.BlockInfo) {
}
}
// shortcutFile sets file mode and modification time, when that's the only
// thing that has changed.
// shortcutFile sets file metadata, when that's the only thing that has
// changed.
func (f *sendReceiveFolder) shortcutFile(file protocol.FileInfo, dbUpdateChan chan<- dbUpdateJob) {
l.Debugln(f, "taking shortcut on", file.Name)
@@ -1228,13 +1228,22 @@ func (f *sendReceiveFolder) shortcutFile(file protocol.FileInfo, dbUpdateChan ch
if !f.IgnorePerms && !file.NoPermissions {
if err = f.mtimefs.Chmod(file.Name, fs.FileMode(file.Permissions&0777)); err != nil {
f.newPullError(file.Name, err)
f.newPullError(file.Name, fmt.Errorf("shortcut file (setting permissions): %w", err))
return
}
}
if f.SyncXattrs {
if err = f.mtimefs.SetXattr(file.Name, file.Platform.Xattrs(), f.XattrFilter); errors.Is(err, fs.ErrXattrsNotSupported) {
l.Debugf("Cannot set xattrs on %q: %v", file.Name, err)
} else if err != nil {
f.newPullError(file.Name, fmt.Errorf("shortcut file (setting xattrs): %w", err))
return
}
}
if err := f.maybeAdjustOwnership(&file, file.Name); err != nil {
f.newPullError(file.Name, err)
f.newPullError(file.Name, fmt.Errorf("shortcut file (setting ownership): %w", err))
return
}
@@ -1253,7 +1262,7 @@ func (f *sendReceiveFolder) shortcutFile(file protocol.FileInfo, dbUpdateChan ch
return fd.Truncate(file.Size + trailerSize)
}, f.mtimefs, file.Name, true)
if err != nil {
f.newPullError(file.Name, err)
f.newPullError(file.Name, fmt.Errorf("writing encrypted file trailer: %w", err))
return
}
}
@@ -1599,13 +1608,22 @@ func (f *sendReceiveFolder) performFinish(file, curFile protocol.FileInfo, hasCu
// Set the correct permission bits on the new file
if !f.IgnorePerms && !file.NoPermissions {
if err := f.mtimefs.Chmod(tempName, fs.FileMode(file.Permissions&0777)); err != nil {
return err
return fmt.Errorf("setting permissions: %w", err)
}
}
// Set extended attributes
if f.SyncXattrs {
if err := f.mtimefs.SetXattr(tempName, file.Platform.Xattrs(), f.XattrFilter); errors.Is(err, fs.ErrXattrsNotSupported) {
l.Debugf("Cannot set xattrs on %q: %v", file.Name, err)
} else if err != nil {
return fmt.Errorf("setting xattrs: %w", err)
}
}
// Set ownership based on file metadata or parent, maybe.
if err := f.maybeAdjustOwnership(&file, tempName); err != nil {
return err
return fmt.Errorf("setting ownership: %w", err)
}
if stat, err := f.mtimefs.Lstat(file.Name); err == nil {
@@ -1613,7 +1631,7 @@ func (f *sendReceiveFolder) performFinish(file, curFile protocol.FileInfo, hasCu
// handle that.
if err := f.scanIfItemChanged(file.Name, stat, curFile, hasCurFile, scanChan); err != nil {
return err
return fmt.Errorf("checking existing file: %w", err)
}
if !curFile.IsDirectory() && !curFile.IsSymlink() && f.inConflict(curFile.Version, file.Version) {
@@ -1629,16 +1647,16 @@ func (f *sendReceiveFolder) performFinish(file, curFile protocol.FileInfo, hasCu
err = f.deleteItemOnDisk(curFile, snap, scanChan)
}
if err != nil {
return err
return fmt.Errorf("moving for conflict: %w", err)
}
} else if !fs.IsNotExist(err) {
return err
return fmt.Errorf("checking existing file: %w", err)
}
// Replace the original content with the new one. If it didn't work,
// leave the temp file in place for reuse.
if err := osutil.RenameOrCopy(f.CopyRangeMethod, f.mtimefs, f.mtimefs, tempName, file.Name); err != nil {
return err
return fmt.Errorf("replacing file: %w", err)
}
// Set the correct timestamp on the new file
@@ -1661,7 +1679,7 @@ func (f *sendReceiveFolder) finisherRoutine(snap *db.Snapshot, in <-chan *shared
}
if err != nil {
f.newPullError(state.file.Name, err)
f.newPullError(state.file.Name, fmt.Errorf("finishing: %w", err))
} else {
minBlocksPerBlock := state.file.BlockSize() / protocol.MinBlockSize
blockStatsMut.Lock()
@@ -1768,6 +1786,15 @@ loop:
lastFile = job.file
}
if !job.file.IsDeleted() && !job.file.IsInvalid() {
// Now that the file is finalized, grab possibly updated
// inode change time from disk into the local FileInfo. We
// use this change time to check for changes to xattrs etc
// on next scan.
if err := f.updateFileInfoChangeTime(&job.file); err != nil {
l.Warnln("Error updating metadata for %q at database commit: %v", job.file.Name, err)
}
}
job.file.Sequence = 0
batch.Append(job.file)
@@ -1878,7 +1905,7 @@ func (f *sendReceiveFolder) newPullError(path string, err error) {
// Establish context to differentiate from errors while scanning.
// Use "syncing" as opposed to "pulling" as the latter might be used
// for errors occurring specifically in the puller routine.
errStr := fmt.Sprintln("syncing:", err)
errStr := fmt.Sprintf("syncing: %s", err)
f.tempPullErrors[path] = errStr
l.Debugf("%v new error for %v: %v", f, path, err)
@@ -1978,7 +2005,7 @@ func (f *sendReceiveFolder) deleteDirOnDiskHandleChildren(dir string, snap *db.S
hasReceiveOnlyChanged = true
return nil
}
diskFile, err := scanner.CreateFileInfo(info, path, f.mtimefs, f.SyncOwnership)
diskFile, err := scanner.CreateFileInfo(info, path, f.mtimefs, f.SyncOwnership, f.SyncXattrs, f.XattrFilter)
if err != nil {
// Lets just assume the file has changed.
scanChan <- path
@@ -1991,6 +2018,7 @@ func (f *sendReceiveFolder) deleteDirOnDiskHandleChildren(dir string, snap *db.S
IgnoreBlocks: true,
IgnoreFlags: protocol.LocalAllFlags,
IgnoreOwnership: !f.SyncOwnership,
IgnoreXattrs: !f.SyncXattrs,
}) {
// File on disk changed compared to what we have in db
// -> schedule scan.
@@ -2055,7 +2083,7 @@ func (f *sendReceiveFolder) scanIfItemChanged(name string, stat fs.FileInfo, ite
// to the database. If there's a mismatch here, there might be local
// changes that we don't know about yet and we should scan before
// touching the item.
statItem, err := scanner.CreateFileInfo(stat, item.Name, f.mtimefs, f.SyncOwnership)
statItem, err := scanner.CreateFileInfo(stat, item.Name, f.mtimefs, f.SyncOwnership, f.SyncXattrs, f.XattrFilter)
if err != nil {
return fmt.Errorf("comparing item on disk to db: %w", err)
}
@@ -2066,6 +2094,7 @@ func (f *sendReceiveFolder) scanIfItemChanged(name string, stat fs.FileInfo, ite
IgnoreBlocks: true,
IgnoreFlags: protocol.LocalAllFlags,
IgnoreOwnership: !f.SyncOwnership,
IgnoreXattrs: !f.SyncXattrs,
}) {
return errModified
}
@@ -2150,6 +2179,22 @@ func (f *sendReceiveFolder) withLimiter(fn func() error) error {
return fn()
}
// updateFileInfoChangeTime updates the inode change time in the FileInfo,
// because that depends on the current, new, state of the file on disk.
func (f *sendReceiveFolder) updateFileInfoChangeTime(file *protocol.FileInfo) error {
info, err := f.mtimefs.Lstat(file.Name)
if err != nil {
return err
}
if ct := info.InodeChangeTime(); !ct.IsZero() {
file.InodeChangeNs = ct.UnixNano()
} else {
file.InodeChangeNs = 0
}
return nil
}
// A []FileError is sent as part of an event and will be JSON serialized.
type FileError struct {
Path string `json:"path"`