diff options
| -rw-r--r-- | src/rabbit_disk_monitor.erl | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/src/rabbit_disk_monitor.erl b/src/rabbit_disk_monitor.erl index 96e90ff53e..4bc6ba09d0 100644 --- a/src/rabbit_disk_monitor.erl +++ b/src/rabbit_disk_monitor.erl @@ -240,7 +240,28 @@ get_disk_free(Dir, {unix, _}) -> Df = os:find_executable("df"), parse_free_unix(rabbit_misc:os_cmd(Df ++ " -kP " ++ Dir)); get_disk_free(Dir, {win32, _}) -> - parse_free_win32(rabbit_misc:os_cmd("dir /-C /W \"" ++ Dir ++ "\"")). + %% On Windows, the Win32 API enforces a limit of 260 characters + %% (MAX_PATH). If we call `dir` with a path longer than that, it + %% fails with "File not found". Starting with Windows 10 version + %% 1607, this limit was removed, but the administrator has to + %% configure that. + %% + %% NTFS supports paths up to 32767 characters. Therefore, paths + %% longer than 260 characters exist but they are "inaccessible" to + %% `dir`. + %% + %% A workaround is to tell the Win32 API to not parse a path and + %% just pass it raw to the underlying filesystem. To do this, the + %% path must be prepended with "\\?\". That's what we do here. + %% + %% However, the underlying filesystem may not support forward + %% slashes transparently, as the Win32 API does. Therefore, we + %% convert all forward slashes to backslashes. + %% + %% See the following page to learn more about this: + %% https://ss64.com/nt/syntax-filenames.html + RawDir = "\\\\?\\" ++ string:replace(Dir, "/", "\\", all), + parse_free_win32(rabbit_misc:os_cmd("dir /-C /W \"" ++ RawDir ++ "\"")). parse_free_unix(Str) -> case string:tokens(Str, "\n") of |