From 1a18d8e6098633f27c228f6ebce8881a061df54c Mon Sep 17 00:00:00 2001
From: Jakob Unterwurzacher
Date: Sun, 1 Jul 2018 15:48:53 +0200
Subject: fsck: rename "CorruptItems" channel to "MitigatedCorruptions"

Make it clear that this channel is only used to report corruptions
that are transparently mitigated and do not return an error to
the user.
---
 internal/fusefrontend/file.go   |  2 +-
 internal/fusefrontend/fs.go     | 24 ++++++++++++++++--------
 internal/fusefrontend/fs_dir.go |  4 ++--
 internal/fusefrontend/xattr.go  |  2 +-
 4 files changed, 20 insertions(+), 12 deletions(-)

(limited to 'internal')

diff --git a/internal/fusefrontend/file.go b/internal/fusefrontend/file.go
index 72319e9..2041154 100644
--- a/internal/fusefrontend/file.go
+++ b/internal/fusefrontend/file.go
@@ -100,7 +100,7 @@ func (f *file) readFileID() ([]byte, error) {
 		if err == io.EOF && n != 0 {
 			tlog.Warn.Printf("readFileID %d: incomplete file, got %d instead of %d bytes",
 				f.qIno.Ino, n, readLen)
-			f.fs.reportCorruptItem(fmt.Sprint(f.qIno.Ino))
+			f.fs.reportMitigatedCorruption(fmt.Sprint(f.qIno.Ino))
 		}
 		return nil, err
 	}
diff --git a/internal/fusefrontend/fs.go b/internal/fusefrontend/fs.go
index 582e6a1..f66e6d4 100644
--- a/internal/fusefrontend/fs.go
+++ b/internal/fusefrontend/fs.go
@@ -38,11 +38,15 @@ type FS struct {
 	// This lock is used by openWriteOnlyFile() to block concurrent opens while
 	// it relaxes the permissions on a file.
 	openWriteOnlyLock sync.RWMutex
-	// CorruptItems is filled with file or xattr names that have been
-	// skipped (ignored) because they were corrupt. This is used by fsck
-	// to inform the user.
-	// Use the reportCorruptItem() function to push an item.
-	CorruptItems chan string
+	// MitigatedCorruptions is used to report data corruption that is internally
+	// mitigated by ignoring the corrupt item. For example, when OpenDir() finds
+	// a corrupt filename, we still return the other valid filenames.
+	// The corruption is logged to syslog to inform the user,	and in addition,
+	// the corrupt filename is logged to this channel via
+	// reportMitigatedCorruption().
+	// "gocryptfs -fsck" reads from the channel to also catch these transparently-
+	// mitigated corruptions.
+	MitigatedCorruptions chan string
 }
 
 var _ pathfs.FileSystem = &FS{} // Verify that interface is implemented.
@@ -607,12 +611,16 @@ func (fs *FS) Access(path string, mode uint32, context *fuse.Context) (code fuse
 	return fuse.ToStatus(syscall.Access(cPath, mode))
 }
 
-func (fs *FS) reportCorruptItem(item string) {
-	if fs.CorruptItems == nil {
+// reportMitigatedCorruption is used to report a corruption that was transparently
+// mitigated and did not return an error to the user. Pass the name of the corrupt
+// item (filename for OpenDir(), xattr name for ListXAttr() etc).
+// See the MitigatedCorruptions channel for more info.
+func (fs *FS) reportMitigatedCorruption(item string) {
+	if fs.MitigatedCorruptions == nil {
 		return
 	}
 	select {
-	case fs.CorruptItems <- item:
+	case fs.MitigatedCorruptions <- item:
 	case <-time.After(1 * time.Second):
 		tlog.Warn.Printf("BUG: reportCorruptItem: timeout")
 		//debug.PrintStack()
diff --git a/internal/fusefrontend/fs_dir.go b/internal/fusefrontend/fs_dir.go
index 089429e..b7bc790 100644
--- a/internal/fusefrontend/fs_dir.go
+++ b/internal/fusefrontend/fs_dir.go
@@ -326,7 +326,7 @@ func (fs *FS) OpenDir(dirName string, context *fuse.Context) ([]fuse.DirEntry, f
 			if err != nil {
 				tlog.Warn.Printf("OpenDir %q: invalid entry %q: Could not read .name: %v",
 					cDirName, cName, err)
-				fs.reportCorruptItem(cName)
+				fs.reportMitigatedCorruption(cName)
 				errorCount++
 				continue
 			}
@@ -339,7 +339,7 @@ func (fs *FS) OpenDir(dirName string, context *fuse.Context) ([]fuse.DirEntry, f
 		if err != nil {
 			tlog.Warn.Printf("OpenDir %q: invalid entry %q: %v",
 				cDirName, cName, err)
-			fs.reportCorruptItem(cName)
+			fs.reportMitigatedCorruption(cName)
 			if runtime.GOOS == "darwin" && cName == dsStoreName {
 				// MacOS creates lots of these files. Log the warning but don't
 				// increment errorCount - does not warrant returning EIO.
diff --git a/internal/fusefrontend/xattr.go b/internal/fusefrontend/xattr.go
index eea67ad..30f417e 100644
--- a/internal/fusefrontend/xattr.go
+++ b/internal/fusefrontend/xattr.go
@@ -106,7 +106,7 @@ func (fs *FS) ListXAttr(path string, context *fuse.Context) ([]string, fuse.Stat
 		name, err := fs.decryptXattrName(curName)
 		if err != nil {
 			tlog.Warn.Printf("ListXAttr: invalid xattr name %q: %v", curName, err)
-			fs.reportCorruptItem(curName)
+			fs.reportMitigatedCorruption(curName)
 			continue
 		}
 		names = append(names, name)
-- 
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