diff options
Diffstat (limited to 'internal/fusefrontend/node_open_create.go')
-rw-r--r-- | internal/fusefrontend/node_open_create.go | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/internal/fusefrontend/node_open_create.go b/internal/fusefrontend/node_open_create.go new file mode 100644 index 0000000..8b31932 --- /dev/null +++ b/internal/fusefrontend/node_open_create.go @@ -0,0 +1,108 @@ +package fusefrontend + +import ( + "context" + "syscall" + + "github.com/hanwen/go-fuse/v2/fs" + "github.com/hanwen/go-fuse/v2/fuse" + + "github.com/rfjakob/gocryptfs/internal/nametransform" + "github.com/rfjakob/gocryptfs/internal/syscallcompat" + "github.com/rfjakob/gocryptfs/internal/tlog" +) + +// Open - FUSE call. Open already-existing file. +// +// Symlink-safe through Openat(). +func (n *Node) Open(ctx context.Context, flags uint32) (fh fs.FileHandle, fuseFlags uint32, errno syscall.Errno) { + dirfd, cName, errno := n.prepareAtSyscall("") + if errno != 0 { + return + } + defer syscall.Close(dirfd) + + rn := n.rootNode() + newFlags := rn.mangleOpenFlags(flags) + // Taking this lock makes sure we don't race openWriteOnlyFile() + rn.openWriteOnlyLock.RLock() + defer rn.openWriteOnlyLock.RUnlock() + + if rn.args.KernelCache { + fuseFlags = fuse.FOPEN_KEEP_CACHE + } + + // Open backing file + fd, err := syscallcompat.Openat(dirfd, cName, newFlags, 0) + // Handle a few specific errors + if err != nil { + if err == syscall.EMFILE { + var lim syscall.Rlimit + syscall.Getrlimit(syscall.RLIMIT_NOFILE, &lim) + tlog.Warn.Printf("Open %q: too many open files. Current \"ulimit -n\": %d", cName, lim.Cur) + } + if err == syscall.EACCES && (int(flags)&syscall.O_ACCMODE) == syscall.O_WRONLY { + fd, err = rn.openWriteOnlyFile(dirfd, cName, newFlags) + } + } + // Could not handle the error? Bail out + if err != nil { + errno = fs.ToErrno(err) + return + } + fh, _, errno = NewFile(fd, cName, rn) + return fh, fuseFlags, errno +} + +// Create - FUSE call. Creates a new file. +// +// Symlink-safe through the use of Openat(). +func (n *Node) Create(ctx context.Context, name string, flags uint32, mode uint32, out *fuse.EntryOut) (inode *fs.Inode, fh fs.FileHandle, fuseFlags uint32, errno syscall.Errno) { + dirfd, cName, errno := n.prepareAtSyscall(name) + if errno != 0 { + return + } + defer syscall.Close(dirfd) + + var err error + fd := -1 + // Make sure context is nil if we don't want to preserve the owner + rn := n.rootNode() + if !rn.args.PreserveOwner { + ctx = nil + } + newFlags := rn.mangleOpenFlags(flags) + // Handle long file name + ctx2 := toFuseCtx(ctx) + if !rn.args.PlaintextNames && nametransform.IsLongContent(cName) { + // Create ".name" + err = rn.nameTransform.WriteLongNameAt(dirfd, cName, name) + if err != nil { + return nil, nil, 0, fs.ToErrno(err) + } + // Create content + fd, err = syscallcompat.OpenatUser(dirfd, cName, newFlags|syscall.O_CREAT|syscall.O_EXCL, mode, ctx2) + if err != nil { + nametransform.DeleteLongNameAt(dirfd, cName) + } + } else { + // Create content, normal (short) file name + fd, err = syscallcompat.OpenatUser(dirfd, cName, newFlags|syscall.O_CREAT|syscall.O_EXCL, mode, ctx2) + } + if err != nil { + // xfstests generic/488 triggers this + if err == syscall.EMFILE { + var lim syscall.Rlimit + syscall.Getrlimit(syscall.RLIMIT_NOFILE, &lim) + tlog.Warn.Printf("Create %q: too many open files. Current \"ulimit -n\": %d", cName, lim.Cur) + } + return nil, nil, 0, fs.ToErrno(err) + } + + fh, st, errno := NewFile(fd, cName, rn) + if errno != 0 { + return + } + inode = n.newChild(ctx, st, out) + return inode, fh, fuseFlags, errno +} |