Remove some remaining traces of dsm_resize().

A couple of obsolete comments and unreachable blocks remained after
commit 3c60d0fa.

Discussion: https://postgr.es/m/CAA4eK1%2B%3DyAFUvpFoHXFi_gm8YqmXN-TtkFH%2BVYjvDLS6-SFq-Q%40mail.gmail.com

diff --git a/src/backend/storage/ipc/dsm_impl.c b/src/backend/storage/ipc/dsm_impl.c
index 78154010aaf3d4c8024bf4c97924036fb5c6bd8c..0ff1f5be91e873d76eb864a57fdc3566f4c3b458 100644 (file)
--- a/src/backend/storage/ipc/dsm_impl.c
+++ b/src/backend/storage/ipc/dsm_impl.c
@@ -245,7 +245,7 @@ dsm_impl_posix(dsm_op op, dsm_handle handle, Size request_size,
        }
 
        /*
-        * Create new segment or open an existing one for attach or resize.
+        * Create new segment or open an existing one for attach.
         *
         * Even though we're not going through fd.c, we should be safe against
         * running out of file descriptors, because of NUM_RESERVED_FDS.  We're
@@ -410,10 +410,6 @@ dsm_impl_sysv(dsm_op op, dsm_handle handle, Size request_size,
        char            name[64];
        int                *ident_cache;
 
-       /* Since resize isn't supported, reattach is a no-op. */
-       if (op == DSM_OP_ATTACH && *mapped_address != NULL)
-               return true;
-
        /*
         * POSIX shared memory and mmap-based shared memory identify segments with
         * names.  To avoid needless error message variation, we use the handle as
@@ -600,10 +596,6 @@ dsm_impl_windows(dsm_op op, dsm_handle handle, Size request_size,
        char            name[64];
        MEMORY_BASIC_INFORMATION info;
 
-       /* Since resize isn't supported, reattach is a no-op. */
-       if (op == DSM_OP_ATTACH && *mapped_address != NULL)
-               return true;
-
        /*
         * Storing the shared memory segment in the Global\ namespace, can allow
         * any process running in any session to access that file mapping object
@@ -814,7 +806,7 @@ dsm_impl_mmap(dsm_op op, dsm_handle handle, Size request_size,
                return true;
        }
 
-       /* Create new segment or open an existing one for attach or resize. */
+       /* Create new segment or open an existing one for attach. */
        flags = O_RDWR | (op == DSM_OP_CREATE ? O_CREAT | O_EXCL : 0);
        if ((fd = OpenTransientFile(name, flags)) == -1)
        {