I wrote:
> Justin Pryzby <pry...@telsasoft.com> writes:
>> Maybe we should lstat() the file to determine if it's a dangling link; if
>> lstat() fails, then skip it. Currently, we use stat(), which shows metdata
>> of
>> a link's *target*. Maybe we'd change that.
> Hm, good point that ENOENT could refer to a symlink's target. Still,
> I'm not sure it's worth going out of our way to disambiguate that,
> given that these directories aren't really supposed to contain symlinks.
> (And on the third hand, if they aren't supposed to, then maybe these
> functions needn't look through any symlinks? In which case just
> substituting lstat for stat would resolve the ambiguity.)
After looking at the callers of pg_ls_dir_files, and noticing that
it's already defined to ignore anything that's not a regular file,
I think switching to lstat makes sense.
I also grepped the other uses of ReadDir[Extended], and didn't see
any other ones that seemed desperately in need of changing.
So the attached seems like a sufficient fix.
regards, tom lane
diff --git a/src/backend/utils/adt/genfile.c b/src/backend/utils/adt/genfile.c
index 01185f2..8429a12 100644
--- a/src/backend/utils/adt/genfile.c
+++ b/src/backend/utils/adt/genfile.c
@@ -596,10 +596,15 @@ pg_ls_dir_files(FunctionCallInfo fcinfo, const char *dir, bool missing_ok)
/* Get the file info */
snprintf(path, sizeof(path), "%s/%s", dir, de->d_name);
- if (stat(path, &attrib) < 0)
+ if (lstat(path, &attrib) < 0)
+ {
+ /* Ignore concurrently-deleted files, else complain */
+ if (errno == ENOENT)
+ continue;
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not stat file \"%s\": %m", path)));
+ }
/* Ignore anything but regular files */
if (!S_ISREG(attrib.st_mode))
