With recent updates, it complains a setup issue while previous everything worked well.
Only a upgrade caused the trouble.
Local Disk Storage Not Readable/Writable
Configured location for storing uploaded files on disk ("/phab/web/files/") does not exist, or is not readable or writable. Verify the directory exists and is readable and writable by the webserver.
Unhandled Exception ("PhutilAggregateException")
However, the location is readable and writable, even chmod -R 777.
When try to do upload, it pops up a message,
All storage engines failed to write file:
- PhabricatorLocalDiskFileStorageEngine: CommandException: Command failed with error #1!
COMMAND mkdir -p '/phab/web/files/56/b5' STDOUT (empty)
STDERR mkdir: cannot create directory `/phab/web/files/56/b5': Permission denied
$ cd /phab/web/files/56/
$ sudo su -s /bin/sh nginx -c "mkdir -p '/phab/web/files/56/b5' "
$ ls -lh
drwxr-xr-x. 2 nginx nginx 4.0K Nov 17 16:52 b5
but webserver fails