jkl1337/duplicacy
1
0
Fork 0
mirror of https://github.com/jkl1337/duplicacy.git synced 2026-01-11 08:04:46 -06:00
Code Issues Packages Projects Releases Wiki Activity

Support for hardlinks to symlinks

Browse Source 
This is a specialized use-case, but it is indeed possible to do this
and can be used if xattrs are attached to the symlink.
This commit is contained in:
John K. Luebs
2023-10-03 23:46:00 -05:00
parent 52e628ac93
commit 4934df4e08
5 changed files with 165 additions and 40 deletions
Download Patch File Download Diff File Expand all files Collapse all files

70
src/duplicacy_backupmanager.go
View File

@@ -705,7 +705,7 @@ func (manager *BackupManager) Restore(top string, revision int, inPlace bool, qu
type hardLinkEntry struct {
entry *Entry
willDownload bool
willExist bool
}
var hardLinkTable []hardLinkEntry
var hardLinks []*Entry
@@ -752,12 +752,16 @@ func (manager *BackupManager) Restore(top string, revision int, inPlace bool, qu
}
fullPath := joinPath(top, remoteEntry.Path)
if remoteEntry.IsLink() {
if stat, _ := os.Lstat(fullPath); stat != nil {
if stat.Mode()&os.ModeSymlink != 0 {
isRegular, link, err := Readlink(fullPath)
if err == nil && link == remoteEntry.Link && !isRegular {
remoteEntry.RestoreMetadata(fullPath, nil, setOwner)
if remoteEntry.IsHardlinkRoot() {
hardLinkTable[len(hardLinkTable)-1].willExist = true
}
continue
}
}
@@ -771,11 +775,33 @@ func (manager *BackupManager) Restore(top string, revision int, inPlace bool, qu
os.Remove(fullPath)
}
if remoteEntry.IsHardlinkRoot() {
hardLinkTable[len(hardLinkTable)-1].willExist = true
} else if remoteEntry.IsHardlinkedFrom() {
i, err := remoteEntry.GetHardlinkId()
if err != nil {
LOG_ERROR("RESTORE_HARDLINK", "Decode error for hardlinked entry %s, %v", remoteEntry.Path, err)
return 0
}
if !hardLinkTable[i].willExist {
hardLinkTable[i] = hardLinkEntry{remoteEntry, true}
} else {
sourcePath := joinPath(top, hardLinkTable[i].entry.Path)
LOG_INFO("RESTORE_HARDLINK", "Hard linking %s to %s", fullPath, sourcePath)
if err := MakeHardlink(sourcePath, fullPath); err != nil {
LOG_ERROR("RESTORE_HARDLINK", "Failed to create hard link %s to %s %v", fullPath, sourcePath, err)
return 0
}
continue
}
}
if err := os.Symlink(remoteEntry.Link, fullPath); err != nil {
LOG_ERROR("RESTORE_SYMLINK", "Can't create symlink %s: %v", remoteEntry.Path, err)
return 0
}
remoteEntry.RestoreMetadata(fullPath, nil, setOwner)
LOG_TRACE("DOWNLOAD_DONE", "Symlink %s updated", remoteEntry.Path)
} else if remoteEntry.IsDir() {
@@ -814,20 +840,21 @@ func (manager *BackupManager) Restore(top string, revision int, inPlace bool, qu
remoteEntry.RestoreMetadata(fullPath, nil, setOwner)
} else {
if remoteEntry.IsHardlinkRoot() {
hardLinkTable[len(hardLinkTable)-1] = hardLinkEntry{remoteEntry, true}
hardLinkTable[len(hardLinkTable)-1].willExist = true
} else if remoteEntry.IsHardlinkedFrom() {
i, err := strconv.ParseUint(remoteEntry.Link, 16, 64)
i, err := remoteEntry.GetHardlinkId()
if err != nil {
LOG_ERROR("RESTORE_HARDLINK", "Decode error in hardlink entry, expected hex int, got %s", remoteEntry.Link)
LOG_ERROR("RESTORE_HARDLINK", "Decode error for hardlinked entry %s, %v", remoteEntry.Path, err)
return 0
}
if !hardLinkTable[i].willDownload {
if !hardLinkTable[i].willExist {
hardLinkTable[i] = hardLinkEntry{remoteEntry, true}
} else {
hardLinks = append(hardLinks, remoteEntry)
continue
}
}
// We can't download files here since fileEntries needs to be sorted
fileEntries = append(fileEntries, remoteEntry)
totalFileSize += remoteEntry.Size
@@ -948,11 +975,32 @@ func (manager *BackupManager) Restore(top string, revision int, inPlace bool, qu
}
for _, linkEntry := range hardLinks {
i, _ := strconv.ParseUint(linkEntry.Link, 16, 64)
i, _ := linkEntry.GetHardlinkId()
sourcePath := joinPath(top, hardLinkTable[i].entry.Path)
fullPath := joinPath(top, linkEntry.Path)
LOG_INFO("RESTORE_HARDLINK", "Hard linking %s to %s", fullPath, sourcePath)
if err := os.Link(sourcePath, fullPath); err != nil {
if stat, _ := os.Lstat(fullPath); stat != nil {
sourceStat, _ := os.Lstat(sourcePath)
if os.SameFile(stat, sourceStat) {
continue
}
if sourceStat == nil {
LOG_WERROR(allowFailures, "RESTORE_HARDLINK",
"Target %s for hardlink %s is missing", sourcePath, linkEntry.Path)
continue
}
if !overwrite {
LOG_WERROR(allowFailures, "DOWNLOAD_OVERWRITE",
"File %s already exists. Please specify the -overwrite option to overwrite", linkEntry.Path)
continue
}
os.Remove(fullPath)
}
LOG_DEBUG("RESTORE_HARDLINK", "Hard linking %s to %s", fullPath, sourcePath)
if err := MakeHardlink(sourcePath, fullPath); err != nil {
LOG_ERROR("RESTORE_HARDLINK", "Failed to create hard link %s to %s", fullPath, sourcePath)
return 0
}
@@ -1142,10 +1190,10 @@ func (manager *BackupManager) UploadSnapshot(chunkOperator *ChunkOperator, top s
entry.StartChunk -= lastEndChunk
lastEndChunk = entry.EndChunk
entry.EndChunk = delta
} else if entry.IsHardlinkedFrom() {
i, err := strconv.ParseUint(entry.Link, 16, 64)
} else if entry.IsHardlinkedFrom() && !entry.IsLink() {
i, err := entry.GetHardlinkId()
if err != nil {
LOG_ERROR("SNAPSHOT_UPLOAD", "Decode error in hardlink entry, expected hex int, got %s", entry.Link)
LOG_ERROR("SNAPSHOT_UPLOAD", "Decode error for hardlinked entry %s, %v", entry.Link, err)
return err
}