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authorMiss Islington (bot) <31488909+miss-islington@users.noreply.github.com>2017-12-01 06:26:31 (GMT)
committerVictor Stinner <victor.stinner@gmail.com>2017-12-01 06:26:31 (GMT)
commit8bcd41040a5f1f9b48a86d0e21f196e4b1f90e4b (patch)
tree11a56145f0c96232e9067ab3bdcba5bb6d469da0
parente10c9de9d74fd4c26b32e6719d96f04a5be6987d (diff)
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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)
-rw-r--r--Misc/NEWS.d/next/Library/2017-11-30-20-38-16.bpo-32186.O42bVe.rst3
-rw-r--r--Modules/_io/fileio.c6
2 files changed, 8 insertions, 1 deletions
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 0000000..ea696c6
--- /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 918fa57..52cbb94 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;