Skip to content

Create and write files whose mode carries no owner-write bit #65

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
Ebrathul wants to merge 3 commits into
base: main
Choose a base branch
from
Open

Create and write files whose mode carries no owner-write bit #65

Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
22a3466
Write through the descriptor from open(), not a fresh one
Ebrathul Aug 25, 2026
9968eea
Implement create() so a read-only file can be created and written
Ebrathul Aug 25, 2026
c71f30b
Harden descriptor-backed create and write
Ebrathul Sep 1, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
52 changes: 34 additions & 18 deletions src/openvfsfuse/openvfsfuse.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -20,6 +20,7 @@
#include "socketthread.h"

#include <chrono>
#include <cstdint>
#include <cstring>
#include <dirent.h>
#include <errno.h>
Expand Down Expand Up @@ -502,6 +503,33 @@ static int openVFSfuse_utimens(const char *orig_path, const struct timespec ts[2
return 0;
}

static int openVFSfuse_create(const char *orig_path, mode_t mode, struct fuse_file_info *fi)
{
const auto path = getInternalPath(orig_path);

const int res = open(path.c_str(), fi->flags, mode);
if (res == -1) {
const auto error = errno;
openvfsfuse_log(path, "create", -1, "create %o", static_cast<unsigned int>(mode));
return -error;
}

if (fchown(res, fuse_get_context()->uid, fuse_get_context()->gid) == -1) {
const auto error = errno;
const auto cleanupError = unlink(path.c_str()) == -1 ? errno : 0;
close(res);
openvfsfuse_log(path, "create", -1, "set ownership after create %o", static_cast<unsigned int>(mode));
if (cleanupError != 0) {
openvfsfuse_log(path, "create", -1, "failed to remove incomplete file: errno %d", cleanupError);
}
return -error;
}
openvfsfuse_log(path, "create", 0, "create %o", static_cast<unsigned int>(mode));
fi->fh = res;

return 0;
}

static int openVFSfuse_open(const char *orig_path, struct fuse_file_info *fi)
{
int res{0};
Expand Down Expand Up @@ -638,31 +666,18 @@ static int openVFSfuse_read(const char *orig_path, char *buf, size_t size, off_t

static int openVFSfuse_write(const char *orig_path, const char *buf, size_t size, off_t offset, struct fuse_file_info *fi)
{
int fd;
int res;
const auto path = getInternalPath(orig_path);
(void)fi;

fd = open(path.c_str(), O_WRONLY);
if (fd == -1) {
openvfsfuse_log(path, "write", 0, "write %zu bytes at offset %jd", size, static_cast<std::intmax_t>(offset));
res = pwrite(fi->fh, buf, size, offset);
if (res == -1) {
res = -errno;
openvfsfuse_log(path, "write", -1, "write %d bytes to %s at offset %d", size, path.c_str(), offset);

return res;
openvfsfuse_log(path, "write", -1, "write %zu bytes at offset %jd", size, static_cast<std::intmax_t>(offset));
} else {
openvfsfuse_log(path, "write", 0, "write %d bytes to %s at offset %d", size, path.c_str(), offset);
openvfsfuse_log(path, "write", 0, "%d bytes written at offset %jd", res, static_cast<std::intmax_t>(offset));
}

res = pwrite(fd, buf, size, offset);

if (res == -1)
res = -errno;
else
openvfsfuse_log(path, "write", 0, "%d bytes written to %s at offset %d", res, path.c_str(), offset);

close(fd);


return res;
}

Expand Down Expand Up @@ -794,6 +809,7 @@ int initializeOpenVFSFuse(openVFSfuse_Args &openVFSArgs)
openVFSfuse_oper.truncate = openVFSfuse_truncate;
openVFSfuse_oper.utimens = openVFSfuse_utimens;
openVFSfuse_oper.open = openVFSfuse_open;
openVFSfuse_oper.create = openVFSfuse_create;
openVFSfuse_oper.read = openVFSfuse_read;
openVFSfuse_oper.write = openVFSfuse_write;
openVFSfuse_oper.statfs = openVFSfuse_statfs;
Expand Down