PROPFIND of a root folder with a S3 external storage folder mounted is very slow

[SergioBertolinSG]

Steps to reproduce

1. Mount an amazon S3 folder and be sure encryption is enabled on it (gear on the right).
2. Upload some files to it.
3. Do:

curl -X PROPFIND -H "Content-Type: text/xml" http://USER:PASSWORD@HOST/remote.php/webdav/ | xmllint --format -

Expected behaviour

Have a quick response.

Actual behaviour

It is quite slow.

  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  3101  100  3101    0     0     79      0  0:00:39  0:00:39 --:--:--   828

Server configuration

Operating system:
Ubuntu 14.04 LTS

Web server:
Apache

Database:
MySQL

PHP version:
5.5.9

ownCloud version: (see ownCloud admin page)
8.1 alpha2

Updated from an older ownCloud or fresh install:
Fresh

Are you using external storage, if yes which one: local/smb/sftp/...
Yes S3.

Are you using encryption:
Yes.

I was testing propfind requests with encryption, but after disabling S3 mounted folder, the request went like a charm, so encryption doesn't slows it down.

Logs

[karlitschek]

@butonic What is your opinion?

[PVince81]

Duplicate of #13147
We need a stat cache for every external storage.

[PVince81]

@jnfrmarks I see you set the milestone. Please reevaluate whether we want 8.1 or 8.2 on #13147.

Note that implementing a stat cache will affect all file operations and would need full regression testing of S3. A stat cache was implemented for SWIFT a while ago but got deferred again to 8.2: #7897

General info about stat caches for external storage: #7910