From 8bcd41040a5f1f9b48a86d0e21f196e4b1f90e4b Mon Sep 17 00:00:00 2001 From: "Miss Islington (bot)" <31488909+miss-islington@users.noreply.github.com> Date: Thu, 30 Nov 2017 22:26:31 -0800 Subject: [PATCH] bpo-32186: Release the GIL during lseek and fstat (GH-4652) (#4661) In _io_FileIO_readall_impl(), lseek() and _Py_fstat_noraise() were called without releasing the GIL. This can cause all threads to hang for unlimited time when calling FileIO.read() and the NFS server is not accessible. (cherry picked from commit 6a89481680b921e7b317c29877bdda9a6031e5ad) --- .../next/Library/2017-11-30-20-38-16.bpo-32186.O42bVe.rst | 3 +++ Modules/_io/fileio.c | 6 +++++- 2 files changed, 8 insertions(+), 1 deletion(-) create mode 100644 Misc/NEWS.d/next/Library/2017-11-30-20-38-16.bpo-32186.O42bVe.rst diff --git a/Misc/NEWS.d/next/Library/2017-11-30-20-38-16.bpo-32186.O42bVe.rst b/Misc/NEWS.d/next/Library/2017-11-30-20-38-16.bpo-32186.O42bVe.rst new file mode 100644 index 0000000000..ea696c6098 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2017-11-30-20-38-16.bpo-32186.O42bVe.rst @@ -0,0 +1,3 @@ +io.FileIO.readall() and io.FileIO.read() now release the GIL when +getting the file size. Fixed hang of all threads with inaccessible NFS +server. Patch by Nir Soffer. diff --git a/Modules/_io/fileio.c b/Modules/_io/fileio.c index 918fa57775..52cbb94b24 100644 --- a/Modules/_io/fileio.c +++ b/Modules/_io/fileio.c @@ -691,10 +691,12 @@ _io_FileIO_readall_impl(fileio *self) Py_ssize_t bytes_read = 0; Py_ssize_t n; size_t bufsize; + int fstat_result; if (self->fd < 0) return err_closed(); + Py_BEGIN_ALLOW_THREADS _Py_BEGIN_SUPPRESS_IPH #ifdef MS_WINDOWS pos = _lseeki64(self->fd, 0L, SEEK_CUR); @@ -702,8 +704,10 @@ _io_FileIO_readall_impl(fileio *self) pos = lseek(self->fd, 0L, SEEK_CUR); #endif _Py_END_SUPPRESS_IPH + fstat_result = _Py_fstat_noraise(self->fd, &status); + Py_END_ALLOW_THREADS - if (_Py_fstat_noraise(self->fd, &status) == 0) + if (fstat_result == 0) end = status.st_size; else end = (Py_off_t)-1; -- 2.50.1