SHR(3) SHR(3)
NAME
shr - global mountpoints
SYNOPSIS
bind '#σ' /shr
#σ/share1
#σc/share1/service1
#σc/share1/service2
...
DESCRIPTION
The shr device provides global mountpoints in the form of
share directories where 9P services can be mounted.
Effectively, it is a global mountpoint registry that is sep-
arate from private namespaces.
The shr device exports a mount tree and a control tree. The
directories in the mount tree #σ are the share mountpoints
themselves, while the directories in #σc contain the service
files of the share.
To create a new share, create the directory #σc/myshare
To mount a service in that share, create the file
#σc/myshare/myserv and then write a text string (suitable
for strtoul; see atof(2)) giving the file descriptor number
of an open 9P service. Any process with the proper permis-
sion may then access #σ/myshare on the mount tree.
The service file can be reopened and passed to mount (see
bind(2)) or added to another share.
Multiple services can be mounted under a share forming a
union directory. New services get mounted before old ones.
Removing the service file unmounts the service from the
share.
Creating shares and mounts requires read-write access in the
share directory. The special user none is prohibited from
these operations.
EXAMPLES
To mount a 9p service from srv(3) to the shr device
mkdir '#σc'/myshare
echo 3 > '#σc'/myshare/myserv <>[3]/srv/myserv
SOURCE
Page 1 Plan 9 (printed 12/22/24)
SHR(3) SHR(3)
/sys/src/9/port/devshr.c
HISTORY
Shr first appeared in 9front (July, 2011).
Page 2 Plan 9 (printed 12/22/24)