Bug 172801

Summary: [libexec] [patch] /usr/libexec/locate.updatedb (and therefore locate(1)) does not work inside a jail
Product: Base System Reporter: Devin Teske <dteske>
Component: kernAssignee: freebsd-bugs (Nobody) <bugs>
Status: Open ---    
Severity: Affects Only Me CC: gonzo, wosch
Priority: Normal Keywords: patch
Version: 8.1-RELEASE   
Hardware: Any   
OS: Any   
Attachments:
Description Flags
file.diff
none
patch.txt none

Description Devin Teske freebsd_committer freebsd_triage 2012-10-16 23:40:01 UTC
Executing 'locate' in a jail returns "locate: database too small: /var/db/locate.database"
 
The database file is 0 length: 
    -r--r--r-- 1 nobody wheel 0 Aug 20 04:15 /var/db/locate.database 

The script /usr/libexec/locate.updatedb is responsible for generating the locate(1) database (above file). Executing '/usr/libexec/locate.updatedb' in a jail returns "/usr/libexec/locate.updatedb: empty variable FILESYSTEMS".

One might be fooled into thinking this is a configuration issue with /etc/locate.rc but it is not. The root-cause is that /usr/libexec/locate.updatedb uses the lsvfs(1) command to get a list of local/non-synthetic filesystem types (and uses this as the default-value for $FILESYSTEMS). Within a jail, the lsvfs(1) output is redacted (see below):

Filesystem                        Refs Flags
-------------------------------- ----- ---------------
                                     1
                                 29542
                                     0
                                     0
                                     4
                                 12342
                                     0
                                     0
                                     7
                                   115
                                     0
                                     0
                                    10

This redacted output results in a NULL default-value for $FILESYSTEMS, resulting in the odd, but true, fatal error message "/usr/libexec/locate.updatedb: empty variable FILESYSTEMS".

ASIDE: The value of $FILESYSTEMS is used by /usr/libexec/locate.updatedb, enumerated to find(1) as a list of "-fstype" arguments when generating the locate(1) database.

It then uses this list to build a series of "-fstype" excludes to pass to find(1) when generating the locate(1) database.

Fix: At the low-level, the problem is two-fold:
1. lsvfs(1) as-used by /usr/libexec/locate.updatedb returns a redacted list within a jail
2. find(1)'s "-fstype" flag does not work within a jail.

At the high-level, the problem is simpler to solve:
1. Make /usr/libexec/locate.updatedb not use lsvfs(1) or the "-fstype" flag of find(1) when running in a jail.

A patch has been attached that applys the above-described "high-level" change, allowing /usr/libexec/locate.db to function properly within a jail (thus allowing locate(1) to work as-expected within a jail).

Patch attached with submission follows:
How-To-Repeat: Execute 'locate' in a jail. Get the following error:

locate: database too small: /var/db/locate.database

Naturally, try and generate /var/db/locate.database by then executing:

/usr/libexec/locate.updatedb

Only to get the following fatal error:

/usr/libexec/locate.updatedb: empty variable FILESYSTEMS

NOTE: The error is misleading and caused by a bug. Please read "Full Description" for further explanation.
Comment 1 Devin Teske freebsd_committer freebsd_triage 2013-03-11 19:17:01 UTC
The previously attached patch didn't work for me on a virgin jail setup.

I've revised/updated it. Could still use a formal looking at by the respective
authors however (read: not intended for commit yet)

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Comment 2 Eitan Adler freebsd_committer freebsd_triage 2018-05-20 23:51:02 UTC
For bugs matching the following conditions:
- Status == In Progress
- Assignee == "bugs@FreeBSD.org"
- Last Modified Year <= 2017

Do
- Set Status to "Open"
Comment 3 Oleksandr Tymoshenko freebsd_committer freebsd_triage 2019-01-19 05:53:45 UTC
Devin, is this patch still relevant?