Acked-by: Alin Gabriel Serdean <aserd...@cloudbasesolutions.com>
> -----Mesaj original----- > De la: dev [mailto:dev-boun...@openvswitch.org] În numele Paul Boca > Trimis: Wednesday, July 13, 2016 8:35 PM > Către: dev@openvswitch.org > Subiect: [ovs-dev] [PATCH V7] windows: Added lockf function and lock PID > file > > If the PID file isn't locked then appctl.py detects it as stale and bails out > without doing anything. Because of this lots of Python tests fail. > Also this protects the PID file from being overwritten. > > I used only shared lock, in order to be compatible with Python tests, which > try to acquire the lock exclusively. On Windows if the exclusive lock is used, > than the read access is denied too for other instances of this file. > > Signed-off-by: Paul-Daniel Boca <pb...@cloudbasesolutions.com> > --- > V2: No changes > V3: No changes > V4: No changes > V5: Removed this patch from Python series. > Removed unused constants and defined 0xFFFF0000 as constant. > Updated commit text. > V6: flock returns now the error of GetLastError. > Also it uses fd parameter instead of the global filep_pidfile. > Removed unused local variable and unnecessary error message. > V7: Keep a shared lock on PID file after the fopen. > This ensures us that at most one process can write the same PID file. > fopen with 'w' on Windows creates a file with FILE_SHARED_WRITE > flag, so anyone with write access on file can write it. > --- > lib/daemon-windows.c | 41 > +++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 41 insertions(+) > > diff --git a/lib/daemon-windows.c b/lib/daemon-windows.c index > 8cf0fea..e6e1452 100644 > --- a/lib/daemon-windows.c > +++ b/lib/daemon-windows.c > @@ -18,6 +18,7 @@ > #include "daemon.h" > #include "daemon-private.h" > #include <stdio.h> > +#include <io.h> > #include <stdlib.h> > #include "dirs.h" > #include "ovs-thread.h" > @@ -26,6 +27,14 @@ > > VLOG_DEFINE_THIS_MODULE(daemon_windows); > > +/* Constants for flock function */ > +#define LOCK_SH 0x0 /* Shared lock. */ > +#define LOCK_EX LOCKFILE_EXCLUSIVE_LOCK /* Exclusive > lock. */ > +#define LOCK_UN 0x80000000 /* Unlock. Custom value. > */ > + > +/* High-order 32 bits of byte range to lock */ #define LOCK_MAX_SIZE > +0xFFFF0000 > + > static bool service_create; /* Was --service specified? */ > static bool service_started; /* Have we dispatched service to start? > */ > > @@ -404,9 +413,35 @@ detach_process(int argc, char *argv[]) } > > static void > +flock(FILE* fd, int operation) > +{ > + HANDLE hFile; > + OVERLAPPED ov = {0}; > + > + hFile = (HANDLE)_get_osfhandle(fileno(fd)); > + if (hFile == INVALID_HANDLE_VALUE) { > + VLOG_FATAL("Invalid handle value"); > + } > + > + if (operation & LOCK_UN) { > + if (UnlockFileEx(hFile, 0, 0, LOCK_MAX_SIZE, &ov) == 0) { > + VLOG_FATAL("Failed to unlock PID file (%s).", > + ovs_lasterror_to_string()); > + } > + } else { > + if (LockFileEx(hFile, operation, 0, 0, LOCK_MAX_SIZE, &ov) == FALSE) > { > + VLOG_FATAL("Failed to lock PID file (%s).", > + ovs_lasterror_to_string()); > + } > + } > +} > + > +static void > unlink_pidfile(void) > { > if (filep_pidfile) { > + /* Remove the shared lock on file */ > + flock(filep_pidfile, LOCK_UN); > fclose(filep_pidfile); > } > if (pidfile) { > @@ -437,6 +472,8 @@ make_pidfile(void) > VLOG_FATAL("failed to open %s (%s)", pidfile, ovs_strerror(errno)); > } > > + flock(filep_pidfile, LOCK_EX); > + > fatal_signal_add_hook(unlink_pidfile, NULL, NULL, true); > > fprintf(filep_pidfile, "%d\n", _getpid()); @@ -444,6 +481,10 @@ > make_pidfile(void) > VLOG_FATAL("Failed to write into the pidfile %s", pidfile); > } > > + flock(filep_pidfile, LOCK_SH); > + /* This will remove the exclusive lock. The shared lock will remain */ > + flock(filep_pidfile, LOCK_UN); > + > /* Don't close the pidfile till the process exits. */ } > > -- > 2.7.2.windows.1 > _______________________________________________ > dev mailing list > dev@openvswitch.org > http://openvswitch.org/mailman/listinfo/dev _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
