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Drop guessOrInventPathFromFD()

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No need to do hacky stuff like that when we already know the original path.
This commit is contained in:
Eelco Dolstra 2025-06-12 11:35:28 +02:00 • committed by Jörg Thalheim
parent e5dc3e84f0
commit 479c356510
6 changed files with 28 additions and 74 deletions
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26
src/libutil/file-descriptor.cc
View file

@ -1,8 +1,5 @@
#include "nix/util/serialise.hh"
#include "nix/util/util.hh"
#include "nix/util/file-system.hh"
#include "util-config-private.hh"
#include <fcntl.h>
#include <unistd.h>
@ -77,29 +74,6 @@ Descriptor AutoCloseFD::get() const
return fd;
}
std::string guessOrInventPathFromFD(Descriptor fd)
{
assert(fd >= 0);
/* On Linux, there's no F_GETPATH available.
* But we can read /proc/ */
#if defined(__linux__)
try {
return readLink(fmt("/proc/self/fd/%1%", fd));
} catch (...) {
}
#elif defined (HAVE_F_GETPATH) && HAVE_F_GETPATH
std::string fdName(PATH_MAX, '\0');
if (fcntl(fd, F_GETPATH, fdName.data()) != -1) {
fdName.resize(strlen(fdName.c_str()));
return fdName;
}
#else
#error "No implementation for retrieving file descriptors path."
#endif
return fmt("<fd %i>", fd);
}
void AutoCloseFD::close()
{

39
src/libutil/file-system.cc
View file

@ -315,19 +315,19 @@ void writeFile(const Path & path, std::string_view s, mode_t mode)
if (!fd)
throw SysError("opening file '%1%'", path);
writeFile(fd, s, mode);
writeFile(fd, path, s, mode);
/* Close explicitly to propagate the exceptions. */
fd.close();
}
void writeFile(AutoCloseFD & fd, std::string_view s, mode_t mode)
void writeFile(AutoCloseFD & fd, const Path & origPath, std::string_view s, mode_t mode)
{
assert(fd);
try {
writeFull(fd.get(), s);
} catch (Error & e) {
e.addTrace({}, "writing file '%1%'", fd.guessOrInventPath());
e.addTrace({}, "writing file '%1%'", origPath);
throw;
}
}
@ -339,7 +339,7 @@ void writeFileAndSync(const Path & path, std::string_view s, mode_t mode)
if (!fd)
throw SysError("opening file '%1%'", path);
writeFile(fd, s, mode);
writeFile(fd, path, s, mode);
fd.fsync();
/* Close explicitly to ensure that exceptions are propagated. */
fd.close();
@ -444,8 +444,6 @@ void recursiveSync(const Path & path)
static void _deletePath(Descriptor parentfd, const std::filesystem::path & path, uint64_t & bytesFreed, std::exception_ptr & ex MOUNTEDPATHS_PARAM)
{
#ifndef _WIN32
/* This ensures that `name` is an immediate child of `parentfd`. */
assert(!path.empty() && path.string().find('/') == std::string::npos && "`name` is an immediate child to `parentfd`");
checkInterrupt();
#ifdef __FreeBSD__
@ -456,13 +454,14 @@ static void _deletePath(Descriptor parentfd, const std::filesystem::path & path,
}
#endif
std::string name(path.native());
std::string name(path.filename());
assert(name != "." && name != ".." && !name.empty());
struct stat st;
if (fstatat(parentfd, name.c_str(), &st,
AT_SYMLINK_NOFOLLOW) == -1) {
if (errno == ENOENT) return;
throw SysError("getting status of '%1%' in directory '%2%'", name, guessOrInventPathFromFD(parentfd));
throw SysError("getting status of %1%", path);
}
if (!S_ISDIR(st.st_mode)) {
@ -493,24 +492,23 @@ static void _deletePath(Descriptor parentfd, const std::filesystem::path & path,
/* Make the directory accessible. */
const auto PERM_MASK = S_IRUSR | S_IWUSR | S_IXUSR;
if ((st.st_mode & PERM_MASK) != PERM_MASK) {
if (fchmodat(parentfd, name.c_str(), st.st_mode | PERM_MASK, 0) == -1) {
throw SysError("chmod '%1%' in directory '%2%'", name, guessOrInventPathFromFD(parentfd));
}
if (fchmodat(parentfd, name.c_str(), st.st_mode | PERM_MASK, 0) == -1)
throw SysError("chmod %1%", path);
}
int fd = openat(parentfd, name.c_str(), O_RDONLY | O_DIRECTORY | O_NOFOLLOW);
if (fd == -1)
throw SysError("opening directory '%1%' in directory '%2%'", name, guessOrInventPathFromFD(parentfd));
throw SysError("opening directory %1%", path);
AutoCloseDir dir(fdopendir(fd));
if (!dir)
throw SysError("opening directory '%1%' in directory '%2%'", name, guessOrInventPathFromFD(parentfd));
throw SysError("opening directory %1%", path);
struct dirent * dirent;
while (errno = 0, dirent = readdir(dir.get())) { /* sic */
checkInterrupt();
std::string childName = dirent->d_name;
if (childName == "." || childName == "..") continue;
_deletePath(dirfd(dir.get()), childName, bytesFreed, ex MOUNTEDPATHS_ARG);
_deletePath(dirfd(dir.get()), path / childName, bytesFreed, ex MOUNTEDPATHS_ARG);
}
if (errno) throw SysError("reading directory %1%", path);
}
@ -519,7 +517,7 @@ static void _deletePath(Descriptor parentfd, const std::filesystem::path & path,
if (unlinkat(parentfd, name.c_str(), flags) == -1) {
if (errno == ENOENT) return;
try {
throw SysError("cannot unlink '%1%' in directory '%2%'", name, guessOrInventPathFromFD(parentfd));
throw SysError("cannot unlink %1%", path);
} catch (...) {
if (!ex)
ex = std::current_exception();
@ -535,19 +533,18 @@ static void _deletePath(Descriptor parentfd, const std::filesystem::path & path,
static void _deletePath(const std::filesystem::path & path, uint64_t & bytesFreed MOUNTEDPATHS_PARAM)
{
Path dir = dirOf(path.string());
if (dir == "")
dir = "/";
assert(path.is_absolute());
assert(path.parent_path() != path);
AutoCloseFD dirfd = toDescriptor(open(dir.c_str(), O_RDONLY));
AutoCloseFD dirfd = toDescriptor(open(path.parent_path().string().c_str(), O_RDONLY));
if (!dirfd) {
if (errno == ENOENT) return;
throw SysError("opening directory '%1%'", path);
throw SysError("opening directory %s", path.parent_path());
}
std::exception_ptr ex;
_deletePath(dirfd.get(), path.filename(), bytesFreed, ex MOUNTEDPATHS_ARG);
_deletePath(dirfd.get(), path, bytesFreed, ex MOUNTEDPATHS_ARG);
if (ex)
std::rethrow_exception(ex);

17
src/libutil/include/nix/util/file-descriptor.hh
View file

@ -106,14 +106,6 @@ void drainFD(
#endif
);
/*
* Will attempt to guess *A* path associated that might lead to the same file as used by this
* file descriptor.
*
* The returned string should NEVER be used as a valid path.
*/
std::string guessOrInventPathFromFD(Descriptor fd);
/**
* Get [Standard Input](https://en.wikipedia.org/wiki/Standard_streams#Standard_input_(stdin))
*/
@ -168,15 +160,6 @@ public:
AutoCloseFD& operator =(const AutoCloseFD & fd) = delete;
AutoCloseFD& operator =(AutoCloseFD&& fd);
Descriptor get() const;
/**
* Will attempt to guess *A* path associated that might lead to the same file as used by this
* file descriptor.
*
* The returned string should NEVER be used as a valid path.
*/
std::string guessOrInventPath() const { return guessOrInventPathFromFD(fd); }
explicit operator bool() const;
Descriptor release();
void close();

4
src/libutil/include/nix/util/file-system.hh
View file

@ -173,18 +173,20 @@ void readFile(const Path & path, Sink & sink, bool memory_map = true);
* Write a string to a file.
*/
void writeFile(const Path & path, std::string_view s, mode_t mode = 0666);
static inline void writeFile(const std::filesystem::path & path, std::string_view s, mode_t mode = 0666)
{
return writeFile(path.string(), s, mode);
}
void writeFile(const Path & path, Source & source, mode_t mode = 0666, bool sync = false);
static inline void writeFile(const std::filesystem::path & path, Source & source, mode_t mode = 0666, bool sync = false)
{
return writeFile(path.string(), source, mode, sync);
}
void writeFile(AutoCloseFD & fd, std::string_view s, mode_t mode = 0666 );
void writeFile(AutoCloseFD & fd, const Path & origPath, std::string_view s, mode_t mode = 0666);
/**
* Write a string to a file and flush the file and its parents direcotry to disk.

2
src/libutil/meson.build
View file

@ -37,8 +37,6 @@ foreach funcspec : check_funcs
configdata.set(define_name, define_value, description: funcspec[1])
endforeach
configdata.set('HAVE_F_GETPATH', cxx.has_header_symbol('fcntl.h', 'F_GETPATH').to_int())
subdir('nix-meson-build-support/libatomic')
if host_machine.system() == 'windows'