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authorJakob Unterwurzacher2020-05-03 15:22:10 +0200
committerJakob Unterwurzacher2020-05-03 15:22:10 +0200
commit518771e4e247762f60c5594de427a8c86f19bd57 (patch)
tree625aed59393508f8f3b61787963012a684b37d8e /internal/fusefrontend_reverse/virtualfile.go
parentdb93a6c54cfd615561207f1bbcf7e665ebc296b6 (diff)
fusefrontend_reverse: use inomap for inode number translation
Gets rid of static inode number value limitations. Fixes https://github.com/rfjakob/gocryptfs/issues/457
Diffstat (limited to 'internal/fusefrontend_reverse/virtualfile.go')
-rw-r--r--internal/fusefrontend_reverse/virtualfile.go52
1 files changed, 22 insertions, 30 deletions
diff --git a/internal/fusefrontend_reverse/virtualfile.go b/internal/fusefrontend_reverse/virtualfile.go
index 963c801..7d1c18c 100644
--- a/internal/fusefrontend_reverse/virtualfile.go
+++ b/internal/fusefrontend_reverse/virtualfile.go
@@ -10,6 +10,7 @@ import (
"github.com/hanwen/go-fuse/fuse"
"github.com/hanwen/go-fuse/fuse/nodefs"
+ "github.com/rfjakob/gocryptfs/internal/inomap"
"github.com/rfjakob/gocryptfs/internal/nametransform"
"github.com/rfjakob/gocryptfs/internal/pathiv"
"github.com/rfjakob/gocryptfs/internal/syscallcompat"
@@ -20,19 +21,10 @@ const (
// virtualFileMode is the mode to use for virtual files (gocryptfs.diriv and
// *.name). They are always readable, as stated in func Access
virtualFileMode = syscall.S_IFREG | 0444
- // inoBaseDirIV is the start of the inode number range that is used
- // for virtual gocryptfs.diriv files. inoBaseNameFile is the thing for
- // *.name files.
- // The value 10^19 is just below 2^60. A power of 10 has been chosen so the
- // "ls -li" output (which is base-10) is easy to read.
- // 10^19 is the largest power of 10 that is smaller than
- // INT64_MAX (=UINT64_MAX/2). This avoids signedness issues.
- inoBaseDirIV = uint64(1000000000000000000)
- inoBaseNameFile = uint64(2000000000000000000)
- // inoBaseMin marks the start of the inode number space that is
- // reserved for virtual files. It is the lowest of the inoBaseXXX values
- // above.
- inoBaseMin = inoBaseDirIV
+ // We use inomap's `Tag` feature to generate unique inode numbers for
+ // virtual files. These are the tags we use.
+ inoTagDirIV = 1
+ inoTagNameFile = 2
)
func (rfs *ReverseFS) newDirIVFile(cRelPath string) (nodefs.File, fuse.Status) {
@@ -42,20 +34,23 @@ func (rfs *ReverseFS) newDirIVFile(cRelPath string) (nodefs.File, fuse.Status) {
return nil, fuse.ToStatus(err)
}
iv := pathiv.Derive(cDir, pathiv.PurposeDirIV)
- return rfs.newVirtualFile(iv, rfs.args.Cipherdir, dir, inoBaseDirIV)
+ return rfs.newVirtualFile(iv, rfs.args.Cipherdir, dir, inoTagDirIV)
}
type virtualFile struct {
// Embed nodefs.defaultFile for a ENOSYS implementation of all methods
nodefs.File
+ // pointer to parent filesystem
+ rfs *ReverseFS
// file content
content []byte
// backing directory
cipherdir string
// path to a parent file (relative to cipherdir)
parentFile string
- // inode number of a virtual file is inode of parent file plus inoBase
- inoBase uint64
+ // inomap `Tag`.
+ // Depending on the file type, either `inoTagDirIV` or `inoTagNameFile`.
+ inoTag uint8
}
// newVirtualFile creates a new in-memory file that does not have a representation
@@ -63,16 +58,17 @@ type virtualFile struct {
// from "parentFile" (plaintext path relative to "cipherdir").
// For a "gocryptfs.diriv" file, you would use the parent directory as
// "parentFile".
-func (rfs *ReverseFS) newVirtualFile(content []byte, cipherdir string, parentFile string, inoBase uint64) (nodefs.File, fuse.Status) {
- if inoBase < inoBaseMin {
- log.Panicf("BUG: virtual inode number base %d is below reserved space", inoBase)
+func (rfs *ReverseFS) newVirtualFile(content []byte, cipherdir string, parentFile string, inoTag uint8) (nodefs.File, fuse.Status) {
+ if inoTag == 0 {
+ log.Panicf("BUG: inoTag for virtual file is zero - this will cause ino collisions!")
}
return &virtualFile{
File: nodefs.NewDefaultFile(),
+ rfs: rfs,
content: content,
cipherdir: cipherdir,
parentFile: parentFile,
- inoBase: inoBase,
+ inoTag: inoTag,
}, fuse.OK
}
@@ -97,22 +93,18 @@ func (f *virtualFile) GetAttr(a *fuse.Attr) fuse.Status {
}
defer syscall.Close(dirfd)
name := filepath.Base(f.parentFile)
- var st unix.Stat_t
- err = syscallcompat.Fstatat(dirfd, name, &st, unix.AT_SYMLINK_NOFOLLOW)
+ var st2 unix.Stat_t
+ err = syscallcompat.Fstatat(dirfd, name, &st2, unix.AT_SYMLINK_NOFOLLOW)
if err != nil {
tlog.Debug.Printf("GetAttr: Fstatat %q: %v\n", f.parentFile, err)
return fuse.ToStatus(err)
}
- if st.Ino > inoBaseMin {
- tlog.Warn.Printf("virtualFile.GetAttr: parent file inode number %d crosses reserved space, max=%d. Returning EOVERFLOW.",
- st.Ino, inoBaseMin)
- return fuse.ToStatus(syscall.EOVERFLOW)
- }
- st.Ino = st.Ino + f.inoBase
+ st := syscallcompat.Unix2syscall(st2)
+ q := inomap.NewQIno(uint64(st.Dev), f.inoTag, uint64(st.Ino))
+ st.Ino = f.rfs.inoMap.Translate(q)
st.Size = int64(len(f.content))
st.Mode = virtualFileMode
st.Nlink = 1
- st2 := syscallcompat.Unix2syscall(st)
- a.FromStat(&st2)
+ a.FromStat(&st)
return fuse.OK
}