BUG #15105: OpenTransientFile() should be paired with CloseTransientFile() rather than close()

The following bug has been logged on the website:

Bug reference: 15105
Logged by: Pan Bian
Email address: bianpan2016(at)163(dot)com
PostgreSQL version: 10.3
Operating system: Linux
Description:

File: src/backend/storage/ipc/dsm_impl.c
Function: dsm_impl_mmap()

Details: The handler opened with OpenTransientFile() should be closed with
CloseTransientFile(). However, in function dsm_impl_mmap(), on a certain
path, the return value of OpenTransientFile() (at line 885) is passed to
close() (at line 926). It is better to use CloseTransientFile() here, as
done at line 909.

For your convenience, I paste the related source code as follows:

845 static bool
846 dsm_impl_mmap(dsm_op op, dsm_handle handle, Size request_size,
847 void **impl_private, void **mapped_address, Size
*mapped_size,
848 int elevel)
849 {
...
883 /* Create new segment or open an existing one for attach or resize.
*/
884 flags = O_RDWR | (op == DSM_OP_CREATE ? O_CREAT | O_EXCL : 0);
885 if ((fd = OpenTransientFile(name, flags, 0600)) == -1)
886 {
887 if (errno != EEXIST)
888 ereport(elevel,
889 (errcode_for_dynamic_shared_memory(),
890 errmsg("could not open shared memory segment
\"%s\": %m",
891 name)));
892 return false;
893 }
894
895 /*
896 * If we're attaching the segment, determine the current size; if
we are
897 * creating or resizing the segment, set the size to the requested
value.
898 */
899 if (op == DSM_OP_ATTACH)
900 {
901 struct stat st;
902
903 if (fstat(fd, &st) != 0)
904 {
905 int save_errno;
906
907 /* Back out what's already been done. */
908 save_errno = errno;
909 CloseTransientFile(fd);
910 errno = save_errno;
911
912 ereport(elevel,
913 (errcode_for_dynamic_shared_memory(),
914 errmsg("could not stat shared memory segment
\"%s\": %m",
915 name)));
916 return false;
917 }
918 request_size = st.st_size;
919 }
920 else if (*mapped_size > request_size && ftruncate(fd,
request_size))
921 {
922 int save_errno;
923
924 /* Back out what's already been done. */
925 save_errno = errno;
926 close(fd);
927 if (op == DSM_OP_CREATE)
928 unlink(name);
929 errno = save_errno;
930
931 ereport(elevel,
932 (errcode_for_dynamic_shared_memory(),
933 errmsg("could not resize shared memory segment \"%s\"
to %zu bytes: %m",
934 name, request_size)));
935 return false;
936 }
...
1038 *mapped_address = address;
1039 *mapped_size = request_size;
1040 CloseTransientFile(fd);
1041
1042 return true;
1043 }

Thanks!