On 2022-08-11 07:55, Thomas Munro wrote:
I checked a few variants:
21.07.2022 15:11 <JUNCTION> HOME [\??\Volume{GUID}\]
09.08.2022 15:06 <JUNCTION> Test1 [\\?\Volume{GUID}\]
09.08.2022 15:06 <JUNCTION> Test2 [\\.\Volume{GUID}\]
09.08.2022 15:17 <JUNCTION> Test3 [\??\Volume{GUID}\]
09.08.2022 15:27 <JUNCTION> Test4 [C:\temp\1]
09.08.2022 15:28 <JUNCTION> Test5 [C:\HOME\Temp\1]
One more thing I wondered about, now that we're following junctions
outside PGDATA: can a junction point to another junction? If so, I
didn't allow for that: stat() gives up after one hop, because I
figured that was enough for the stuff we expect inside PGDATA and I
couldn't find any evidence in the man pages that referred to chains.
But if you *are* allowed to create a junction "c:\huey" that points to
junction "c:\dewey" that points to "c:\louie", and then you do initdb
-D c:\huey\pgdata, then I guess it would fail. Would you mind
checking if that is a real possibility, and if so, testing this
chain-following patch to see if it fixes it?
I made some junctions and rechecked both patches.
11.08.2022 16:11 <JUNCTION> donald [C:\huey]
11.08.2022 13:23 <JUNCTION> huey [C:\dewey]
11.08.2022 13:23 <JUNCTION> dewey [C:\louie]
11.08.2022 16:57 <DIR> louie
With the small attached patch initdb succeeded in any of these
"directories". If the junction chain is too long, initdb fails with
"could not create directory" as expected.
initdb -D huey/pgdata
...
Success.
initdb -N -D donald
...
Success.
11.08.2022 17:32 <DIR> 1
11.08.2022 17:32 <JUNCTION> 2 [C:\1]
11.08.2022 17:32 <JUNCTION> 3 [C:\2]
11.08.2022 17:32 <JUNCTION> 4 [C:\3]
11.08.2022 17:32 <JUNCTION> 5 [C:\4]
11.08.2022 17:32 <JUNCTION> 6 [C:\5]
11.08.2022 17:32 <JUNCTION> 7 [C:\6]
11.08.2022 17:32 <JUNCTION> 8 [C:\7]
11.08.2022 17:32 <JUNCTION> 9 [C:\8]
11.08.2022 17:32 <JUNCTION> 10 [C:\9]
initdb -D 10/pgdata
...
creating directory 10/pgdata ... initdb: error: could not create
directory "10": File exists
initdb -D 9/pgdata
...
Success.
--- win32stat.c.bak 2022-08-11 17:15:10.775412600 +0700
+++ win32stat.c 2022-08-11 16:47:41.992805700 +0700
@@ -186,9 +186,12 @@
{
int loops = 0;
int ret;
+ char curr[MAXPGPATH];
ret = _pglstat64(name, buf);
+ strlcpy(curr, name, MAXPGPATH);
+
/* Do we need to follow a symlink (junction point)? */
while (ret == 0 && S_ISLNK(buf->st_mode))
{
@@ -211,7 +214,7 @@
* That could be optimized, but stat() on symlinks is probably rare
* and this way is simple.
*/
- size = readlink(name, next, sizeof(next));
+ size = readlink(curr, next, sizeof(next));
if (size < 0)
{
if (errno == EACCES &&
@@ -230,6 +233,7 @@
next[size] = 0;
ret = _pglstat64(next, buf);
+ strcpy(curr, next);
}
return ret;
