NetBSD/lib/libp2k/p2k.3

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.Dd July 11, 2022
.Dt P2K 3
.Os
.Sh NAME
.Nm p2k
.Nd puffs to kernel vfs translation library
.Sh LIBRARY
p2k Library (libp2k, \-lp2k)
.Sh SYNOPSIS
.In rump/p2k.h
.Ft struct p2k_mount *
.Fn p2k_init "uint32_t puffs_flags"
.Ft void
.Fn p2k_cancel "struct p2k_mount *p2m" "int error"
.Ft int
.Fo p2k_setup_fs
.Fa "struct p2k_mount *p2m" "const char *vfsname" "const char *devpath"
.Fa "const char *mountpath" "int mntflags" "void *arg" "size_t alen"
.Fc
.Fo p2k_setup_diskfs
.Fa "struct p2k_mount *p2m" "const char *vfsname" "const char *devpath"
.Fa "int partition" "const char *mountpath" "int mntflags"
.Fa "void *arg" "size_t alen"
.Fc
.Ft int
.Fn p2k_mainloop "struct p2k_mount *p2m"
.Ft int
.Fo p2k_run_fs
.Fa "const char *vfsname" "const char *devpath" "const char *mountpath"
.Fa "int mntflags" "void *arg" "size_t alen" "uint32_t puffs_flags"
.Fc
.Ft int
.Fo p2k_run_diskfs
.Fa "const char *vfsname" "const char *devpath" "int partition"
.Fa "const char *mountpath" "int mntflags" "void *arg" "size_t alen"
.Fa "uint32_t puffs_flags"
.Fc
.Sh DESCRIPTION
The
.Nm
library translates the puffs protocol to the kernel
.Xr vfs 9
protocol and back again.
It can therefore be used to mount and run kernel file system code as
a userspace daemon.
.Pp
Calling the library interface function mounts the file system and,
if successful, starts handling requests.
The parameters are handled by
.Fn ukfs_mount
(see
.Xr ukfs 3 ) ,
with the exception that
.Fa mountpath
and
.Fa puffs_flags
are handled by
.Xr puffs 3 .
The "run_fs" variants of the interfaces are provided as a convenience
for the common case.
They execute all of init, setup and mainloop in one call.
.Sh ENVIRONMENT
The following environment variables affect the behaviour of
.Nm .
They are useful mostly for debugging purposes.
The flags are environment variables because typically the command line
arguments to
.Nm
utilities are parsed using versions not aware of
.Nm
options; for example, the
.Xr rump_cd9660 8
arguments are really parsed by
.Xr mount_cd9660 8 .
.Bl -tag -width "XP2K_NOCACHE_PAGE" -offset 2n
.It Dv P2K_DEBUG
Do not detach from tty and print information about each puffs operation.
In case the daemon receives
.Dv SIGINFO
(typically from ctrl-T), it dumps out the status of the mount point.
Sending
.Dv SIGUSR1
causes a dump of all the vnodes (verbose).
.It Dv P2K_NODETACH
Do not detach from tty.
.It Dv P2K_NOCACHE_PAGE
Do not use the puffs page cache.
.It Dv P2K_NOCACHE_NAME
Do not use the puffs name cache.
.It Dv P2K_NOCACHE
Do not use the puffs page or name cache.
.It Dv P2K_WIZARDUID
If set, use the value of the variable to determine the UID of the
caller of each operation instead of the actual caller supplied by
.Xr puffs 3 .
This can be used for example to simplify modifying an OS installation's
root image as a non-root user.
.El
.Sh SEE ALSO
.Xr puffs 3 ,
.Xr rump 3 ,
.Xr ukfs 3 ,
.Xr rump_cd9660 8 ,
.Xr rump_efs 8 ,
.Xr rump_ext2fs 8 ,
.Xr rump_ffs 8 ,
.Xr rump_hfs 8 ,
.Xr rump_lfs 8 ,
.Xr rump_msdos 8 ,
.Xr rump_nfs 8 ,
.Xr rump_ntfs 8 ,
.Xr rump_syspuffs 8 ,
.Xr rump_sysvbfs 8 ,
.Xr rump_tmpfs 8 ,
.Xr rump_udf 8