>From d6031eb51e66b96ac490255f437539aaaa5b8544 Mon Sep 17 00:00:00 2001 From: Richard Jones Date: Fri, 30 Oct 2009 16:13:13 +0000 Subject: [PATCH 4/4] FUSE filesystem support. This implements FUSE filesystem support so that any libguestfs- accessible disk image can be mounted as a local filesystem. Note: file writes (ie. write(2) system call) is not yet implemented. The API needs more test coverage, particularly lesser-used system calls. The big unresolved issue is UID/GID mapping between guest filesystem IDs and the host. It's not easy to automate this because you need extra details about the guest itself in order to get to its UID->username map (eg. /etc/passwd from the guest). --- .gitignore | 3 + HACKING | 3 + Makefile.am | 5 + README | 2 + TODO | 35 +-- bootstrap | 2 + configure.ac | 11 +- fuse/Makefile.am | 62 +++ fuse/dircache.c | 408 +++++++++++++++++++ fuse/dircache.h | 44 ++ fuse/guestmount.c | 1105 +++++++++++++++++++++++++++++++++++++++++++++++++++ fuse/guestmount.pod | 146 +++++++ m4/.gitignore | 2 + po/POTFILES.in | 4 + 14 files changed, 1805 insertions(+), 27 deletions(-) create mode 100644 fuse/Makefile.am create mode 100644 fuse/dircache.c create mode 100644 fuse/dircache.h create mode 100644 fuse/guestmount.c create mode 100644 fuse/guestmount.pod diff --git a/.gitignore b/.gitignore index ffa9764..fbe7998 100644 --- a/.gitignore +++ b/.gitignore @@ -54,6 +54,8 @@ fish/completion.c fish/guestfish fish/rc_protocol.c fish/rc_protocol.h +fuse/guestmount +fuse/guestmount.1 guestfish.1 guestfish-actions.pod guestfs.3 @@ -72,6 +74,7 @@ hivex/hivexget hivex/hivexml html/guestfish.1.html html/guestfs.3.html +html/guestmount.1.html html/hivex.3.html html/hivexget.1.html html/hivexml.1.html diff --git a/HACKING b/HACKING index cc5b1c2..5752ec3 100644 --- a/HACKING +++ b/HACKING @@ -83,6 +83,9 @@ examples/ fish/ Guestfish (the command-line program / shell) +fuse/ + FUSE (userspace filesystem) built on top of libguestfs. + haskell/ Haskell bindings. diff --git a/Makefile.am b/Makefile.am index 0b905ca..a4f4b0b 100644 --- a/Makefile.am +++ b/Makefile.am @@ -34,6 +34,10 @@ if HAVE_TOOLS SUBDIRS += tools endif +if HAVE_FUSE +SUBDIRS += fuse +endif + if HAVE_OCAML SUBDIRS += ocaml ocaml/examples endif @@ -134,6 +138,7 @@ html/recipes.html: $(wildcard recipes/*.sh) $(wildcard recipes/*.html) $(wildcar HTMLFILES = \ html/guestfs.3.html \ html/guestfish.1.html \ + html/guestmount.1.html \ html/hivex.3.html \ html/hivexget.1.html \ html/hivexml.1.html \ diff --git a/README b/README index 41902ea..0877775 100644 --- a/README +++ b/README @@ -52,6 +52,8 @@ Requirements - libxml2 +- (Optional) FUSE to build the FUSE module + - (Optional) Augeas (http://augeas.net/) - perldoc (pod2man, pod2text) to generate the manual pages and diff --git a/TODO b/TODO index fc14cdc..9c09557 100644 --- a/TODO +++ b/TODO @@ -12,33 +12,16 @@ Python bindings Ideas for the Python bindings: https://www.redhat.com/archives/fedora-virt/2009-April/msg00114.html -FTP server or FUSE? -------------------- +FUSE API +-------- + +The API needs more test coverage, particularly lesser-used system +calls. -Originally we had intended to implement an NFS server inside the -appliance, which would allow the guest filesystems to be mounted on -the host, and large changes to be made. We eventually rejected the -idea of using NFS, partly because it requires root to mount -filesystems in the host, and partly because of problems handling UID -mappings between host and guest filesystem. - -Then we look at implementing an FTP server instead. FTP clients are -widely available for many languages, don't require root, and don't -have any UID mapping problems. However there is the problem of -getting the TCP connection into the guest, and that FTP requires a -secondary data connection either in or out of the guest (the NFS -situation is even more dire). - -Thirdly we looked at implementing a FUSE-based filesystem. This is -plausible - it could be implemented just by adding the additional FUSE -operations to the standard guestfs(3) API, and then implementing a -simple FUSE daemon. (The FUSE website has some very helpful -documentation and examples). I [RWMJ] am not particularly convinced -that a FUSE-based filesystem would really be useful to anyone, but am -prepared to accept patches if someone does all the work. - -See also the mountlo project: -http://sourceforge.net/project/showfiles.php?group_id=121684&package_id=150116 +The big unresolved issue is UID/GID mapping between guest filesystem +IDs and the host. It's not easy to automate this because you need +extra details about the guest itself in order to get to its +UID->username map (eg. /etc/passwd from the guest). BufferIn -------- diff --git a/bootstrap b/bootstrap index c92d1e1..0f8bf20 100755 --- a/bootstrap +++ b/bootstrap @@ -63,6 +63,8 @@ closeout gitlog-to-changelog gnu-make gnumakefile +hash +hash-pjw ignore-value maintainer-makefile manywarnings diff --git a/configure.ac b/configure.ac index e11de0c..fb538c3 100644 --- a/configure.ac +++ b/configure.ac @@ -421,6 +421,13 @@ PKG_CHECK_MODULES([LIBXML2], [libxml-2.0]) AC_SUBST([LIBXML2_CFLAGS]) AC_SUBST([LIBXML2_LIBS]) +dnl FUSE is optional to build the FUSE module. +HAVE_FUSE=yes +PKG_CHECK_MODULES([FUSE],[fuse],,[ + HAVE_FUSE=no + AC_MSG_WARN([FUSE library and headers are missing, so optional FUSE module won't be built])]) +AM_CONDITIONAL([HAVE_FUSE],[test "x$HAVE_FUSE" = "xyes"]) + dnl Check for OCaml (optional, for OCaml bindings). AC_PROG_OCAML AC_PROG_FINDLIB @@ -726,7 +733,8 @@ AC_CONFIG_FILES([Makefile libguestfs.pc gnulib/lib/Makefile gnulib/tests/Makefile - hivex/Makefile + hivex/Makefile + fuse/Makefile ocaml/META perl/Makefile.PL]) AC_OUTPUT @@ -756,6 +764,7 @@ if test "x$HAVE_INSPECTOR" = "x"; then echo "yes"; else echo "no"; fi echo -n "virt-* tools ........................ " if test "x$HAVE_TOOLS" = "x"; then echo "yes"; else echo "no"; fi echo "supermin appliance .................. $enable_supermin" +echo "FUSE filesystem ..................... $HAVE_FUSE" echo echo "If any optional component is configured 'no' when you expected 'yes'" echo "then you should check the preceeding messages." diff --git a/fuse/Makefile.am b/fuse/Makefile.am new file mode 100644 index 0000000..5d5ea30 --- /dev/null +++ b/fuse/Makefile.am @@ -0,0 +1,62 @@ +# libguestfs +# Copyright (C) 2009 Red Hat Inc. +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 2 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program; if not, write to the Free Software +# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + +EXTRA_DIST = fusexmp.c fusexmp_fh.c + +if HAVE_FUSE + +bin_PROGRAMS = guestmount + +guestmount_SOURCES = \ + dircache.c \ + dircache.h \ + guestmount.c + +guestmount_CFLAGS = \ + -I$(top_srcdir)/src -I$(top_builddir)/src \ + -I$(srcdir)/../gnulib/lib -I../gnulib/lib \ + -DGUESTFS_DEFAULT_PATH='"$(libdir)/guestfs"' \ + $(FUSE_CFLAGS) \ + $(WARN_CFLAGS) $(WERROR_CFLAGS) + +guestmount_LDADD = \ + $(FUSE_LIBS) -lulockmgr \ + $(top_builddir)/src/libguestfs.la \ + ../gnulib/lib/libgnu.la + +man_MANS = guestmount.1 + +guestmount.1: guestmount.pod + $(POD2MAN) \ + --section 1 \ + -c "Virtualization Support" \ + --name "guestmount" \ + --release "$(PACKAGE_NAME)-$(PACKAGE_VERSION)" \ + $< > $@-t; mv $@-t $@ + +noinst_DATA = \ + $(top_builddir)/html/guestmount.1.html + +$(top_builddir)/html/guestmount.1.html: guestmount.pod + mkdir -p $(top_builddir)/html + cd $(top_builddir) && pod2html \ + --css 'pod.css' \ + --htmldir html \ + --outfile html/guestmount.1.html \ + fuse/guestmount.pod + +endif diff --git a/fuse/dircache.c b/fuse/dircache.c new file mode 100644 index 0000000..545b9f3 --- /dev/null +++ b/fuse/dircache.c @@ -0,0 +1,408 @@ +/* guestmount - mount guests using libguestfs and FUSE + * Copyright (C) 2009 Red Hat Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + * Derived from the example program 'fusexmp.c': + * Copyright (C) 2001-2007 Miklos Szeredi + * + * This program can be distributed under the terms of the GNU GPL. + * See the file COPYING. + */ + +#include + +#include +#include +#include +#include +#include +#include +#include + +#include + +#include "hash.h" +#include "hash-pjw.h" + +#include "dircache.h" + +extern int verbose; +extern int dir_cache_timeout; + +static inline char * +bad_cast (char const *s) +{ + return (char *) s; +} + +/* Note on attribute caching: FUSE can cache filesystem attributes for + * short periods of time (configurable via -o attr_timeout). It + * doesn't cache xattrs, and in any case FUSE caching doesn't solve + * the problem that we have to make a series of guestfs_lstat and + * guestfs_lgetxattr calls when we first list a directory (thus, many + * round trips). + * + * For this reason, we also implement a readdir cache here which is + * invoked when a readdir call is made. readdir is modified so that + * as well as reading the directory, it also requests all the stat + * structures, xattrs and readlinks of all entries in the directory, + * and these are added to the cache here (for a short, configurable + * period of time) in anticipation that they will be needed + * immediately afterwards, which is usually the case when the user is + * doing an "ls"-like operation. + * + * You can still use FUSE attribute caching on top of this mechanism + * if you like. + */ + +struct lsc_entry { /* lstat cache entry */ + char *pathname; /* full path to the file */ + time_t timeout; /* when this entry expires */ + struct stat statbuf; /* statbuf */ +}; + +struct xac_entry { /* xattr cache entry */ + /* NB first two fields must be same as lsc_entry */ + char *pathname; /* full path to the file */ + time_t timeout; /* when this entry expires */ + struct guestfs_xattr_list *xattrs; +}; + +struct rlc_entry { /* readlink cache entry */ + /* NB first two fields must be same as lsc_entry */ + char *pathname; /* full path to the file */ + time_t timeout; /* when this entry expires */ + char *link; +}; + +static size_t +gen_hash (void const *x, size_t table_size) +{ + struct lsc_entry const *p = x; + return hash_pjw (p->pathname, table_size); +} + +static bool +gen_compare (void const *x, void const *y) +{ + struct lsc_entry const *a = x; + struct lsc_entry const *b = y; + return strcmp (a->pathname, b->pathname) == 0; +} + +static void +lsc_free (void *x) +{ + if (x) { + struct lsc_entry *p = x; + + free (p->pathname); + free (p); + } +} + +static void +xac_free (void *x) +{ + if (x) { + struct xac_entry *p = x; + + guestfs_free_xattr_list (p->xattrs); + lsc_free (x); + } +} + +static void +rlc_free (void *x) +{ + if (x) { + struct rlc_entry *p = x; + + free (p->link); + lsc_free (x); + } +} + +static Hash_table *lsc_ht, *xac_ht, *rlc_ht; + +void +init_dir_caches (void) +{ + lsc_ht = hash_initialize (1024, NULL, gen_hash, gen_compare, lsc_free); + xac_ht = hash_initialize (1024, NULL, gen_hash, gen_compare, xac_free); + rlc_ht = hash_initialize (1024, NULL, gen_hash, gen_compare, rlc_free); + if (!lsc_ht || !xac_ht || !rlc_ht) { + fprintf (stderr, "guestmount: could not initialize dir cache hashtables\n"); + exit (1); + } +} + +void +free_dir_caches (void) +{ + hash_free (lsc_ht); + hash_free (xac_ht); + hash_free (rlc_ht); +} + +struct gen_remove_data { + time_t now; + Hash_table *ht; + Hash_data_freer freer; +}; + +static bool +gen_remove_if_expired (void *x, void *data) +{ + /* XXX hash_do_for_each was observed calling this function + * with x == NULL. + */ + if (x) { + struct lsc_entry *p = x; + struct gen_remove_data *d = data; + + if (p->timeout < d->now) { + if (verbose) + fprintf (stderr, "dir cache: expiring entry %p (%s)\n", + p, p->pathname); + d->freer (hash_delete (d->ht, x)); + } + } + + return 1; +} + +static void +gen_remove_all_expired (Hash_table *ht, Hash_data_freer freer, time_t now) +{ + struct gen_remove_data data; + data.now = now; + data.ht = ht; + data.freer = freer; + + /* Careful reading of the documentation to hash _seems_ to indicate + * that this is safe, _provided_ we use the default thresholds (in + * particular, no shrink threshold). + */ + hash_do_for_each (ht, gen_remove_if_expired, &data); +} + +void +dir_cache_remove_all_expired (time_t now) +{ + gen_remove_all_expired (lsc_ht, lsc_free, now); + gen_remove_all_expired (xac_ht, xac_free, now); + gen_remove_all_expired (rlc_ht, rlc_free, now); +} + +static int +gen_replace (Hash_table *ht, struct lsc_entry *new_entry, Hash_data_freer freer) +{ + struct lsc_entry *old_entry; + + old_entry = hash_delete (ht, new_entry); + freer (old_entry); + + if (verbose && old_entry) + fprintf (stderr, "dir cache: this entry replaced old entry %p (%s)\n", + old_entry, old_entry->pathname); + + old_entry = hash_insert (ht, new_entry); + if (old_entry == NULL) { + perror ("hash_insert"); + freer (new_entry); + return -1; + } + assert (old_entry == new_entry); + + return 0; +} + +int +lsc_insert (const char *path, const char *name, time_t now, + struct stat const *statbuf) +{ + struct lsc_entry *entry; + + entry = malloc (sizeof *entry); + if (entry == NULL) { + perror ("malloc"); + return -1; + } + + size_t len = strlen (path) + strlen (name) + 2; + entry->pathname = malloc (len); + if (entry->pathname == NULL) { + perror ("malloc"); + free (entry); + return -1; + } + if (strcmp (path, "/") == 0) + snprintf (entry->pathname, len, "/%s", name); + else + snprintf (entry->pathname, len, "%s/%s", path, name); + + memcpy (&entry->statbuf, statbuf, sizeof entry->statbuf); + + entry->timeout = now + dir_cache_timeout; + + if (verbose) + fprintf (stderr, "dir cache: inserting lstat entry %p (%s)\n", + entry, entry->pathname); + + return gen_replace (lsc_ht, entry, lsc_free); +} + +int +xac_insert (const char *path, const char *name, time_t now, + struct guestfs_xattr_list *xattrs) +{ + struct xac_entry *entry; + + entry = malloc (sizeof *entry); + if (entry == NULL) { + perror ("malloc"); + return -1; + } + + size_t len = strlen (path) + strlen (name) + 2; + entry->pathname = malloc (len); + if (entry->pathname == NULL) { + perror ("malloc"); + free (entry); + return -1; + } + if (strcmp (path, "/") == 0) + snprintf (entry->pathname, len, "/%s", name); + else + snprintf (entry->pathname, len, "%s/%s", path, name); + + entry->xattrs = xattrs; + + entry->timeout = now + dir_cache_timeout; + + if (verbose) + fprintf (stderr, "dir cache: inserting xattr entry %p (%s)\n", + entry, entry->pathname); + + return gen_replace (xac_ht, (struct lsc_entry *) entry, xac_free); +} + +int +rlc_insert (const char *path, const char *name, time_t now, + char *link) +{ + struct rlc_entry *entry; + + entry = malloc (sizeof *entry); + if (entry == NULL) { + perror ("malloc"); + return -1; + } + + size_t len = strlen (path) + strlen (name) + 2; + entry->pathname = malloc (len); + if (entry->pathname == NULL) { + perror ("malloc"); + free (entry); + return -1; + } + if (strcmp (path, "/") == 0) + snprintf (entry->pathname, len, "/%s", name); + else + snprintf (entry->pathname, len, "%s/%s", path, name); + + entry->link = link; + + entry->timeout = now + dir_cache_timeout; + + if (verbose) + fprintf (stderr, "dir cache: inserting readlink entry %p (%s)\n", + entry, entry->pathname); + + return gen_replace (rlc_ht, (struct lsc_entry *) entry, rlc_free); +} + +const struct stat * +lsc_lookup (const char *pathname) +{ + const struct lsc_entry key = { .pathname = bad_cast (pathname) }; + struct lsc_entry *entry; + time_t now; + + time (&now); + + entry = hash_lookup (lsc_ht, &key); + if (entry && entry->timeout >= now) + return &entry->statbuf; + else + return NULL; +} + +const struct guestfs_xattr_list * +xac_lookup (const char *pathname) +{ + const struct xac_entry key = { .pathname = bad_cast (pathname) }; + struct xac_entry *entry; + time_t now; + + time (&now); + + entry = hash_lookup (xac_ht, &key); + if (entry && entry->timeout >= now) + return entry->xattrs; + else + return NULL; +} + +const char * +rlc_lookup (const char *pathname) +{ + const struct rlc_entry key = { .pathname = bad_cast (pathname) }; + struct rlc_entry *entry; + time_t now; + + time (&now); + + entry = hash_lookup (rlc_ht, &key); + if (entry && entry->timeout >= now) + return entry->link; + else + return NULL; +} + +static void +lsc_remove (Hash_table *ht, const char *pathname, Hash_data_freer freer) +{ + const struct lsc_entry key = { .pathname = bad_cast (pathname) }; + struct lsc_entry *entry; + + entry = hash_delete (ht, &key); + + if (verbose) + fprintf (stderr, "dir cache: invalidating entry %p (%s)\n", + entry, entry->pathname); + + freer (entry); +} + +void +dir_cache_invalidate (const char *path) +{ + lsc_remove (lsc_ht, path, lsc_free); + lsc_remove (xac_ht, path, xac_free); + lsc_remove (rlc_ht, path, rlc_free); +} diff --git a/fuse/dircache.h b/fuse/dircache.h new file mode 100644 index 0000000..adc117e --- /dev/null +++ b/fuse/dircache.h @@ -0,0 +1,44 @@ +/* guestmount - mount guests using libguestfs and FUSE + * Copyright (C) 2009 Red Hat Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + * Derived from the example program 'fusexmp.c': + * Copyright (C) 2001-2007 Miklos Szeredi + * + * This program can be distributed under the terms of the GNU GPL. + * See the file COPYING. + */ + +#ifndef GUESTMOUNT_DIRCACHE_H +#define GUESTMOUNT_DIRCACHE_H 1 + +#include +#include +#include + +extern void init_dir_caches (void); +extern void free_dir_caches (void); +extern void dir_cache_remove_all_expired (time_t now); +extern void dir_cache_invalidate (const char *path); + +extern int lsc_insert (const char *path, const char *name, time_t now, struct stat const *statbuf); +extern int xac_insert (const char *path, const char *name, time_t now, struct guestfs_xattr_list *xattrs); +extern int rlc_insert (const char *path, const char *name, time_t now, char *link); +extern const struct stat *lsc_lookup (const char *pathname); +extern const struct guestfs_xattr_list *xac_lookup (const char *pathname); +extern const char *rlc_lookup (const char *pathname); + +#endif /* GUESTMOUNT_DIRCACHE_H */ diff --git a/fuse/guestmount.c b/fuse/guestmount.c new file mode 100644 index 0000000..788ab72 --- /dev/null +++ b/fuse/guestmount.c @@ -0,0 +1,1105 @@ +/* guestmount - mount guests using libguestfs and FUSE + * Copyright (C) 2009 Red Hat Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + * Derived from the example program 'fusexmp.c': + * Copyright (C) 2001-2007 Miklos Szeredi + * + * This program can be distributed under the terms of the GNU GPL. + * See the file COPYING. + */ + +#define FUSE_USE_VERSION 26 + +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#include "progname.h" + +#include "dircache.h" + +/* See */ +#ifndef ENOATTR +#define ENOATTR ENODATA +#endif + +#ifdef HAVE_GETTEXT +#include "gettext.h" +#define _(str) dgettext(PACKAGE, (str)) +//#define N_(str) dgettext(PACKAGE, (str)) +#else +#define _(str) str +//#define N_(str) str +#endif + +static inline char * +bad_cast (char const *s) +{ + return (char *) s; +} + +static guestfs_h *g = NULL; +static int read_only = 0; +int verbose = 0; +int dir_cache_timeout = 5; + +/* This is ugly: guestfs errors are strings, FUSE wants -errno. We + * have to do the conversion as best we can. + */ +#define MAX_ERRNO 256 + +static int +error (void) +{ + int i; + const char *err = guestfs_last_error (g); + + if (!err) + return -EINVAL; + + /* Print the real error message on stderr. */ + fprintf (stderr, "%s\n", err); + + /* Add a few of our own ... */ + + /* This indicates guestfsd died. Translate into a hard EIO error. + * Arguably we could relaunch the guest if we hit this error. + */ + if (strstr (err, "call launch before using this function")) + return -EIO; + + /* See if it matches an errno string in the host. */ + for (i = 0; i < MAX_ERRNO; ++i) { + const char *e = strerror (i); + if (e && strstr (err, e) != NULL) + return -i; + } + + /* Too bad, return a generic error. */ + return -EINVAL; +} + +static struct guestfs_xattr_list * +copy_xattr_list (const struct guestfs_xattr *first, size_t num) +{ + struct guestfs_xattr_list *xattrs; + + xattrs = malloc (sizeof *xattrs); + if (xattrs == NULL) { + perror ("malloc"); + return NULL; + } + + xattrs->len = num; + xattrs->val = malloc (num * sizeof (struct guestfs_xattr)); + if (xattrs->val == NULL) { + perror ("malloc"); + free (xattrs); + return NULL; + } + + size_t i; + for (i = 0; i < num; ++i) { + xattrs->val[i].attrname = strdup (first[i].attrname); + xattrs->val[i].attrval_len = first[i].attrval_len; + xattrs->val[i].attrval = malloc (first[i].attrval_len); + memcpy (xattrs->val[i].attrval, first[i].attrval, first[i].attrval_len); + } + + return xattrs; +} + +static int +fg_readdir (const char *path, void *buf, fuse_fill_dir_t filler, + off_t offset, struct fuse_file_info *fi) +{ + time_t now; + time (&now); + + dir_cache_remove_all_expired (now); + + struct guestfs_dirent_list *ents; + + ents = guestfs_readdir (g, path); + if (ents == NULL) + return error (); + + size_t i; + for (i = 0; i < ents->len; ++i) { + struct stat stat; + memset (&stat, 0, sizeof stat); + + stat.st_ino = ents->val[i].ino; + switch (ents->val[i].ftyp) { + case 'b': stat.st_mode = S_IFBLK; break; + case 'c': stat.st_mode = S_IFCHR; break; + case 'd': stat.st_mode = S_IFDIR; break; + case 'f': stat.st_mode = S_IFIFO; break; + case 'l': stat.st_mode = S_IFLNK; break; + case 'r': stat.st_mode = S_IFREG; break; + case 's': stat.st_mode = S_IFSOCK; break; + case 'u': + case '?': + default: stat.st_mode = 0; + } + + /* Copied from the example, which also ignores 'offset'. I'm + * not quite sure how this is ever supposed to work on large + * directories. XXX + */ + if (filler (buf, ents->val[i].name, &stat, 0)) + break; + } + + /* Now prepopulate the directory caches. This step is just an + * optimization, don't worry if it fails. + */ + char **names = malloc ((ents->len + 1) * sizeof (char *)); + if (names) { + for (i = 0; i < ents->len; ++i) + names[i] = ents->val[i].name; + names[i] = NULL; + + struct guestfs_stat_list *ss = guestfs_lstatlist (g, path, names); + if (ss) { + for (i = 0; i < ss->len; ++i) { + if (ss->val[i].ino >= 0) { + struct stat statbuf; + + statbuf.st_dev = ss->val[i].dev; + statbuf.st_ino = ss->val[i].ino; + statbuf.st_mode = ss->val[i].mode; + statbuf.st_nlink = ss->val[i].nlink; + statbuf.st_uid = ss->val[i].uid; + statbuf.st_gid = ss->val[i].gid; + statbuf.st_rdev = ss->val[i].rdev; + statbuf.st_size = ss->val[i].size; + statbuf.st_blksize = ss->val[i].blksize; + statbuf.st_blocks = ss->val[i].blocks; + statbuf.st_atime = ss->val[i].atime; + statbuf.st_mtime = ss->val[i].mtime; + statbuf.st_ctime = ss->val[i].ctime; + + lsc_insert (path, names[i], now, &statbuf); + } + } + guestfs_free_stat_list (ss); + } + + struct guestfs_xattr_list *xattrs = guestfs_lxattrlist (g, path, names); + if (xattrs) { + size_t ni, num; + struct guestfs_xattr *first; + struct guestfs_xattr_list *copy; + for (i = 0, ni = 0; i < xattrs->len; ++i, ++ni) { + assert (strlen (xattrs->val[i].attrname) == 0); + if (xattrs->val[i].attrval_len > 0) { + ++i; + first = &xattrs->val[i]; + num = 0; + for (; i < xattrs->len && strlen (xattrs->val[i].attrname) > 0; ++i) + num++; + + copy = copy_xattr_list (first, num); + if (copy) + xac_insert (path, names[ni], now, copy); + + i--; + } + } + guestfs_free_xattr_list (xattrs); + } + + char **links = guestfs_readlinklist (g, path, names); + if (links) { + for (i = 0; names[i] != NULL; ++i) { + if (links[i][0]) + /* Note that rlc_insert owns the string links[i] after this, */ + rlc_insert (path, names[i], now, links[i]); + else + /* which is why we have to free links[i] here. */ + free (links[i]); + } + free (links); /* free the array, not the strings */ + } + + free (names); + } + + guestfs_free_dirent_list (ents); + + return 0; +} + +static int +fg_getattr (const char *path, struct stat *statbuf) +{ + const struct stat *buf; + + buf = lsc_lookup (path); + if (buf) { + memcpy (statbuf, buf, sizeof *statbuf); + return 0; + } + + struct guestfs_stat *r; + + r = guestfs_lstat (g, path); + if (r == NULL) + return error (); + + statbuf->st_dev = r->dev; + statbuf->st_ino = r->ino; + statbuf->st_mode = r->mode; + statbuf->st_nlink = r->nlink; + statbuf->st_uid = r->uid; + statbuf->st_gid = r->gid; + statbuf->st_rdev = r->rdev; + statbuf->st_size = r->size; + statbuf->st_blksize = r->blksize; + statbuf->st_blocks = r->blocks; + statbuf->st_atime = r->atime; + statbuf->st_mtime = r->mtime; + statbuf->st_ctime = r->ctime; + + guestfs_free_stat (r); + + return 0; +} + +/* XXX It's not clear what access is being tested here. If this + * daemon runs as root, then access always succeeds. guestfsd always + * runs as root, so no access test there is possible. + */ +static int +fg_access (const char *path, int mask) +{ + int r = guestfs_exists (g, path); + if (r == -1) + return error (); + + if (mask == F_OK) + return r ? 0 : -EACCES; + + int ok = 1; + /* if the file exists, it's readable */ + if (mask & R_OK) + ok &= r; + /* if the file exists and we're not mounted r/o, it's writable + * XXX on error return -EROFS + */ + if (mask & W_OK) + ok &= r & !read_only; + /* if the file exists, presume it's executable here */ + if (mask & X_OK) + ok &= r; + return ok ? 0 : -EACCES; +} + +static int +fg_readlink (const char *path, char *buf, size_t size) +{ + const char *r; + int free_it = 0; + + r = rlc_lookup (path); + if (!r) { + r = guestfs_readlink (g, path); + if (r == NULL) + return error (); + free_it = 1; + } + + /* Note this is different from the real readlink(2) syscall. FUSE wants + * the string to be always nul-terminated, even if truncated. + */ + size_t len = strlen (r); + if (len > size - 1) + len = size - 1; + + memcpy (buf, r, len); + buf[len] = '\0'; + + if (free_it) + free ((char *) r); + + return 0; +} + +static int +fg_mknod (const char *path, mode_t mode, dev_t rdev) +{ + int r; + + if (read_only) return -EROFS; + + dir_cache_invalidate (path); + + r = guestfs_mknod (g, mode, major (rdev), minor (rdev), path); + if (r == -1) + return error (); + + return 0; +} + +static int +fg_mkdir (const char *path, mode_t mode) +{ + int r; + + if (read_only) return -EROFS; + + dir_cache_invalidate (path); + + r = guestfs_mkdir_mode (g, path, mode); + if (r == -1) + return error (); + + return 0; +} + +static int +fg_unlink (const char *path) +{ + int r; + + if (read_only) return -EROFS; + + dir_cache_invalidate (path); + + r = guestfs_rm (g, path); + if (r == -1) + return error (); + + return 0; +} + +static int +fg_rmdir (const char *path) +{ + int r; + + if (read_only) return -EROFS; + + dir_cache_invalidate (path); + + r = guestfs_rmdir (g, path); + if (r == -1) + return error (); + + return 0; +} + +static int +fg_symlink (const char *from, const char *to) +{ + int r; + + if (read_only) return -EROFS; + + dir_cache_invalidate (to); + + r = guestfs_ln_s (g, to, from); + if (r == -1) + return error (); + + return 0; +} + +static int +fg_rename (const char *from, const char *to) +{ + int r; + + if (read_only) return -EROFS; + + dir_cache_invalidate (to); + + /* XXX It's not clear how close the 'mv' command is to the + * rename syscall. We might need to add the rename syscall + * to the guestfs(3) API. + */ + r = guestfs_mv (g, from, to); + if (r == -1) + return error (); + + return 0; +} + +static int +fg_link (const char *from, const char *to) +{ + int r; + + if (read_only) return -EROFS; + + dir_cache_invalidate (to); + + r = guestfs_ln (g, to, from); + if (r == -1) + return error (); + + return 0; +} + +static int +fg_chmod (const char *path, mode_t mode) +{ + int r; + + if (read_only) return -EROFS; + + dir_cache_invalidate (path); + + r = guestfs_chmod (g, mode, path); + if (r == -1) + return error (); + + return 0; +} + +static int +fg_chown (const char *path, uid_t uid, gid_t gid) +{ + int r; + + if (read_only) return -EROFS; + + dir_cache_invalidate (path); + + r = guestfs_lchown (g, uid, gid, path); + if (r == -1) + return error (); + + return 0; +} + +static int +fg_truncate (const char *path, off_t size) +{ + int r; + + if (read_only) return -EROFS; + + dir_cache_invalidate (path); + + r = guestfs_truncate_size (g, path, size); + if (r == -1) + return error (); + + return 0; +} + +static int +fg_utimens (const char *path, const struct timespec ts[2]) +{ + int r; + + if (read_only) return -EROFS; + + dir_cache_invalidate (path); + + time_t atsecs = ts[0].tv_sec; + long atnsecs = ts[0].tv_nsec; + time_t mtsecs = ts[1].tv_sec; + long mtnsecs = ts[1].tv_nsec; + + if (atnsecs == UTIME_NOW) + atnsecs = -1; + if (atnsecs == UTIME_OMIT) + atnsecs = -2; + if (mtnsecs == UTIME_NOW) + mtnsecs = -1; + if (mtnsecs == UTIME_OMIT) + mtnsecs = -2; + + r = guestfs_utimens (g, path, atsecs, atnsecs, mtsecs, mtnsecs); + if (r == -1) + return error (); + + return 0; +} + +/* This call is quite hard to emulate through the guestfs(3) API. In + * one sense it's a little like access (see above) because it tests + * whether opening a file would succeed given the flags. But it also + * has side effects such as truncating the file if O_TRUNC is given. + * Therefore we need to emulate it ... painfully. + */ +static int +fg_open (const char *path, struct fuse_file_info *fi) +{ + int r, exists; + + if (fi->flags & O_WRONLY) { + if (read_only) + return -EROFS; + } + + exists = guestfs_exists (g, path); + if (exists == -1) + return error (); + + if (fi->flags & O_CREAT) { + if (read_only) + return -EROFS; + + dir_cache_invalidate (path); + + /* Exclusive? File must not exist already. */ + if (fi->flags & O_EXCL) { + if (exists) + return -EEXIST; + } + + /* Create? Touch it and optionally truncate it. */ + r = guestfs_touch (g, path); + if (r == -1) + return error (); + + if (fi->flags & O_TRUNC) { + r = guestfs_truncate (g, path); + if (r == -1) + return error (); + } + } else { + /* Not create, just check it exists. */ + if (!exists) + return -ENOENT; + } + + return 0; +} + +static int +fg_read (const char *path, char *buf, size_t size, off_t offset, + struct fuse_file_info *fi) +{ + char *r; + size_t rsize; + + if (verbose) + fprintf (stderr, "fg_read: %s: size %zu offset %zu\n", + path, size, offset); + + /* The guestfs protocol limits size to somewhere over 2MB. We just + * reduce the requested size here accordingly and push the problem + * up to every user. http://www.jwz.org/doc/worse-is-better.html + */ + const size_t limit = 2 * 1024 * 1024; + if (size > limit) + size = limit; + + r = guestfs_pread (g, path, size, offset, &rsize); + if (r == NULL) + return error (); + + /* This should never happen, but at least it stops us overflowing + * the output buffer if it does happen. + */ + if (rsize > size) + rsize = size; + + memcpy (buf, r, rsize); + free (r); + + return rsize; +} + +static int +fg_write (const char *path, const char *buf, size_t size, + off_t offset, struct fuse_file_info *fi) +{ + if (read_only) return -EROFS; + + dir_cache_invalidate (path); + + return -ENOSYS; /* XXX */ +} + +static int +fg_statfs (const char *path, struct statvfs *stbuf) +{ + struct guestfs_statvfs *r; + + r = guestfs_statvfs (g, path); + if (r == NULL) + return error (); + + stbuf->f_bsize = r->bsize; + stbuf->f_frsize = r->frsize; + stbuf->f_blocks = r->blocks; + stbuf->f_bfree = r->bfree; + stbuf->f_bavail = r->bavail; + stbuf->f_files = r->files; + stbuf->f_ffree = r->ffree; + stbuf->f_favail = r->favail; + stbuf->f_fsid = r->fsid; + stbuf->f_flag = r->flag; + stbuf->f_namemax = r->namemax; + + guestfs_free_statvfs (r); + + return 0; +} + +static int +fg_release (const char *path, struct fuse_file_info *fi) +{ + /* Just a stub. This method is optional and can safely be left + * unimplemented. + */ + return 0; +} + +/* Emulate this by calling sync. */ +static int fg_fsync(const char *path, int isdatasync, + struct fuse_file_info *fi) +{ + int r; + + r = guestfs_sync (g); + if (r == -1) + return error (); + + return 0; +} + +static int +fg_setxattr (const char *path, const char *name, const char *value, + size_t size, int flags) +{ + int r; + + if (read_only) return -EROFS; + + dir_cache_invalidate (path); + + /* XXX Underlying guestfs(3) API doesn't understand the flags. */ + r = guestfs_lsetxattr (g, name, value, size, path); + if (r == -1) + return error (); + + return 0; +} + +/* The guestfs(3) API for getting xattrs is much easier to use + * than the real syscall. Unfortunately we now have to emulate + * the real syscall using that API :-( + */ +static int +fg_getxattr (const char *path, const char *name, char *value, + size_t size) +{ + const struct guestfs_xattr_list *xattrs; + int free_attrs = 0; + + xattrs = xac_lookup (path); + if (xattrs == NULL) { + xattrs = guestfs_lgetxattrs (g, path); + if (xattrs == NULL) + return error (); + free_attrs = 1; + } + + size_t i; + int r = -ENOATTR; + for (i = 0; i < xattrs->len; ++i) { + if (strcmp (xattrs->val[i].attrname, name) == 0) { + size_t sz = xattrs->val[i].attrval_len; + if (sz > size) + sz = size; + memcpy (value, xattrs->val[i].attrval, sz); + r = 0; + break; + } + } + + if (free_attrs) + guestfs_free_xattr_list ((struct guestfs_xattr_list *) xattrs); + + return r; +} + +/* Ditto as above. */ +static int +fg_listxattr (const char *path, char *list, size_t size) +{ + const struct guestfs_xattr_list *xattrs; + int free_attrs = 0; + + xattrs = xac_lookup (path); + if (xattrs == NULL) { + xattrs = guestfs_lgetxattrs (g, path); + if (xattrs == NULL) + return error (); + free_attrs = 1; + } + + size_t i; + ssize_t copied = 0; + for (i = 0; i < xattrs->len; ++i) { + size_t len = strlen (xattrs->val[i].attrname) + 1; + if (size >= len) { + memcpy (list, xattrs->val[i].attrname, len); + size -= len; + list += len; + copied += len; + } else { + copied = -ERANGE; + break; + } + } + + if (free_attrs) + guestfs_free_xattr_list ((struct guestfs_xattr_list *) xattrs); + + return copied; +} + +static int +fg_removexattr(const char *path, const char *name) +{ + int r; + + if (read_only) return -EROFS; + + dir_cache_invalidate (path); + + r = guestfs_lremovexattr (g, name, path); + if (r == -1) + return error (); + + return 0; +} + +static struct fuse_operations fg_operations = { + .getattr = fg_getattr, + .access = fg_access, + .readlink = fg_readlink, + .readdir = fg_readdir, + .mknod = fg_mknod, + .mkdir = fg_mkdir, + .symlink = fg_symlink, + .unlink = fg_unlink, + .rmdir = fg_rmdir, + .rename = fg_rename, + .link = fg_link, + .chmod = fg_chmod, + .chown = fg_chown, + .truncate = fg_truncate, + .utimens = fg_utimens, + .open = fg_open, + .read = fg_read, + .write = fg_write, + .statfs = fg_statfs, + .release = fg_release, + .fsync = fg_fsync, + .setxattr = fg_setxattr, + .getxattr = fg_getxattr, + .listxattr = fg_listxattr, + .removexattr = fg_removexattr, +}; + +struct drv { + struct drv *next; + char *filename; +}; + +struct mp { + struct mp *next; + char *device; + char *mountpoint; +}; + +static void add_drives (struct drv *); +static void mount_mps (struct mp *); + +static void __attribute__((noreturn)) +usage (int status) +{ + if (status != EXIT_SUCCESS) + fprintf (stderr, _("Try `%s --help' for more information.\n"), + program_name); + else { + fprintf (stdout, + _("%s: FUSE module for libguestfs\n" + "%s lets you mount a virtual machine filesystem\n" + "Copyright (C) 2009 Red Hat Inc.\n" + "Usage:\n" + " %s [--options] [-- [--FUSE-options]] mountpoint\n" + "Options:\n" + " -a|--add image Add image\n" + " --dir-cache-timeout Set readdir cache timeout (default 5 sec)\n" + " -m|--mount dev[:mnt] Mount dev on mnt (if omitted, /)\n" + " -n|--no-sync Don't autosync\n" + " -r|--ro Mount read-only\n" + " --selinux Enable SELinux support\n" + " --trace Trace guestfs API calls (to stderr)\n" + " -v|--verbose Verbose messages\n" + " -V|--version Display version and exit\n" + "FUSE options aren't documented here. To get a list of options\n" + "supported by FUSE itself, do:\n" + " %s -- --help\n" + ), + program_name, program_name, program_name, program_name); + } + exit (status); +} + +int +main (int argc, char *argv[]) +{ + enum { HELP_OPTION = CHAR_MAX + 1 }; + + /* The command line arguments are broadly compatible with (a subset + * of) guestfish. Thus we have to deal mainly with -a, -m and --ro. + */ + static const char *options = "a:m:nrv?V"; + static const struct option long_options[] = { + { "add", 1, 0, 'a' }, + { "dir-cache-timeout", 1, 0, 0 }, + { "help", 0, 0, HELP_OPTION }, + { "mount", 1, 0, 'm' }, + { "no-sync", 0, 0, 'n' }, + { "ro", 0, 0, 'r' }, + { "selinux", 0, 0, 0 }, + { "trace", 0, 0, 0 }, + { "verbose", 0, 0, 'v' }, + { "version", 0, 0, 'V' }, + { 0, 0, 0, 0 } + }; + + struct drv *drvs = NULL; + struct drv *drv; + struct mp *mps = NULL; + struct mp *mp; + char *p; + int c, i, r; + int option_index; + struct sigaction sa; + struct fuse *fuse; + char *mountpoint; + int multithreaded; + + /* LC_ALL=C is required so we can parse error messages. */ + setenv ("LC_ALL", "C", 1); + + /* Set global program name that is not polluted with libtool artifacts. */ + set_program_name (argv[0]); + + memset (&sa, 0, sizeof sa); + sa.sa_handler = SIG_IGN; + sa.sa_flags = SA_RESTART; + sigaction (SIGPIPE, &sa, NULL); + + init_dir_caches (); + + g = guestfs_create (); + if (g == NULL) { + fprintf (stderr, _("guestfs_create: failed to create handle\n")); + exit (1); + } + + guestfs_set_autosync (g, 1); + + /* If developing, add ./appliance to the path. Note that libtools + * interferes with this because uninstalled guestfish is a shell + * script that runs the real program with an absolute path. Detect + * that too. + * + * BUT if LIBGUESTFS_PATH environment variable is already set by + * the user, then don't override it. + */ + if (getenv ("LIBGUESTFS_PATH") == NULL && + argv[0] && + (argv[0][0] != '/' || strstr (argv[0], "/.libs/lt-") != NULL)) + guestfs_set_path (g, "appliance:" GUESTFS_DEFAULT_PATH); + + for (;;) { + c = getopt_long (argc, argv, options, long_options, &option_index); + if (c == -1) break; + + switch (c) { + case 0: /* options which are long only */ + if (strcmp (long_options[option_index].name, "dir-cache-timeout") == 0) + dir_cache_timeout = atoi (optarg); + else if (strcmp (long_options[option_index].name, "selinux") == 0) + guestfs_set_selinux (g, 1); + else if (strcmp (long_options[option_index].name, "trace") == 0) + guestfs_set_trace (g, 1); + else { + fprintf (stderr, _("%s: unknown long option: %s (%d)\n"), + program_name, long_options[option_index].name, option_index); + exit (1); + } + break; + + case 'a': + if (access (optarg, R_OK) != 0) { + perror (optarg); + exit (1); + } + drv = malloc (sizeof (struct drv)); + if (!drv) { + perror ("malloc"); + exit (1); + } + drv->filename = optarg; + drv->next = drvs; + drvs = drv; + break; + + case 'm': + mp = malloc (sizeof (struct mp)); + if (!mp) { + perror ("malloc"); + exit (1); + } + p = strchr (optarg, ':'); + if (p) { + *p = '\0'; + mp->mountpoint = p+1; + } else + mp->mountpoint = bad_cast ("/"); + mp->device = optarg; + mp->next = mps; + mps = mp; + break; + + case 'n': + guestfs_set_autosync (g, 0); + break; + + case 'r': + read_only = 1; + break; + + case 'v': + verbose++; + guestfs_set_verbose (g, verbose); + break; + + case 'V': + printf ("%s %s\n", program_name, PACKAGE_VERSION); + exit (0); + + case HELP_OPTION: + usage (0); + + default: + usage (1); + } + } + + /* We must have at least one -a and at least one -m. */ + if (!drvs || !mps) { + fprintf (stderr, + _("%s: must have at least one -a and at least one -m option\n"), + program_name); + exit (1); + } + + add_drives (drvs); + if (guestfs_launch (g) == -1) + exit (1); + mount_mps (mps); + + /* FUSE example does this, not clear if it's necessary, but ... */ + if (guestfs_umask (g, 0) == -1) + exit (1); + + /* At the last minute, remove the libguestfs error handler. In code + * above this point, the default error handler has been used which + * sends all errors to stderr. Now before entering FUSE itself we + * want to silence errors so we can convert them (see error() + * function above). + */ + guestfs_set_error_handler (g, NULL, NULL); + + /* Skip our args. Rest are passed to FUSE. */ + argc -= optind-1; + for (i = 1; i <= argc; ++i) + argv[i] = argv[optind+i-1]; + + fuse = fuse_setup (argc, argv, &fg_operations, sizeof fg_operations, + &mountpoint, &multithreaded, NULL); + if (fuse == NULL) { + fprintf (stderr, _("%s: failed to initialize FUSE\n"), program_name); + exit (1); + } + + /* IGNORE multithreaded flag. The guestfs API must not be used + * uncontrolled from multiple threads. + */ + r = fuse_loop (fuse); + + fuse_teardown (fuse, mountpoint); + free_dir_caches (); + + exit (r == -1 ? 1 : 0); +} + +/* List is built in reverse order, so add them in reverse order. */ +static void +add_drives (struct drv *drv) +{ + int r; + + if (drv) { + add_drives (drv->next); + if (!read_only) + r = guestfs_add_drive (g, drv->filename); + else + r = guestfs_add_drive_ro (g, drv->filename); + if (r == -1) + exit (1); + } +} + +/* List is built in reverse order, so mount them in reverse order. */ +static void +mount_mps (struct mp *mp) +{ + int r; + + if (mp) { + mount_mps (mp->next); + if (!read_only) + r = guestfs_mount (g, mp->device, mp->mountpoint); + else + r = guestfs_mount_ro (g, mp->device, mp->mountpoint); + if (r == -1) + exit (1); + } +} diff --git a/fuse/guestmount.pod b/fuse/guestmount.pod new file mode 100644 index 0000000..366a7f4 --- /dev/null +++ b/fuse/guestmount.pod @@ -0,0 +1,146 @@ +=encoding utf8 + +=head1 NAME + +guestmount - Mount a guest filesystem on the host using FUSE and libguestfs + +=head1 SYNOPSIS + + guestmount [--options] -a disk.img -m device [-- [--FUSE-options]] mountpoint + +=head1 DESCRIPTION + +The guestmount program can be used to mount virtual machine +filesystems and other disk images on the host. It uses libguestfs for +access to the guest filesystem, and FUSE (the "filesystem in +userspace") to make it appear as a mountable device. + +Along with other options, you have to give at least one device (I<-a> +option) and at least one mountpoint (I<-m> option). How this works is +better explained in the L manual page, or you can use +L and/or the the wrapper script +C to help you. + +=head1 EXAMPLES + + guestmount -a windows.img -m /dev/sda1 --ro /mnt + + guestmount -a linux.img -m /dev/VG/LV -m /dev/sda1:/boot --ro /mnt + +To get virt-inspector to do the hard work of detecting guest +mountpoints for you: + + guestmount $(virt-inspector --ro-fish MyGuest) /mnt + +(or use --fish if you don't want it to be a read only mount). + +If you want to trace the libguestfs calls but without excessive +debugging, we recommend: + + guestmount [-a ... -m ...] --trace -- -f /mnt + +If you want to debug the program, we recommend: + + guestmount [-a ... -m ...] --trace --verbose -- -f /mnt + +=head1 OPTIONS + +FUSE itself provides additional options which are not listed on this +page. You can see the FUSE options available by doing: + + guestmount -- --help + +=over 4 + +=item B<-a image> | B<--add image> + +Add a block device or virtual machine image. + +=item B<--dir-cache-timeout N> + +Set the readdir cache timeout to I seconds, the default being 5 +seconds. The readdir cache [actually, there are several +semi-independent caches] is populated after a readdir(2) call with the +stat and extended attributes of the files in the directory, in +anticipation that they will be requested soon after. + +There is also a different attribute cache implemented by FUSE +(see the FUSE option I<-o attr_timeout>), but the FUSE cache +does not anticipate future requests, only cache existing ones. + +=item B<-m dev[:mnt]> | B<--mount dev[:mnt]> + +Mount the named partition or logical volume on the given mountpoint +B (this has nothing to do with mountpoints in the host). + +If the mountpoint is omitted, it defaults to C. You have to mount +something on C. + +=item B<-n> | B<--no-sync> + +By default, we attempt to sync the guest disk when the FUSE mountpoint +is unmounted. If you specify this option, then we don't attempt to +sync the disk. See the discussion of autosync in the L +manpage. + +=item B<-r> | B<--ro> + +Add devices and mount everything read-only. Also disallow writes and +make the disk appear read-only to FUSE. + +This is highly recommended if you are not going to edit the guest +disk. If the guest is running and this option is I supplied, +then there is a strong risk of disk corruption in the guest. We try +to prevent this from happening, but it is not always possible. + +=item B<--selinux> + +Enable SELinux support for the guest. + +=item B<--trace> + +Trace libguestfs calls (to stderr). + +=item B<-v> | B<--verbose> + +Enable verbose messages from underlying libguestfs. + +=item B<-V> | B<--version> + +Display the program version and exit. + +=back + +=head1 SEE ALSO + +L, +L, +L, +L, +L, +L, +L, +L. + +=head1 AUTHORS + +Richard W.M. Jones (C) + +=head1 COPYRIGHT + +Copyright (C) 2009 Red Hat Inc. +L + +This program is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2 of the License, or +(at your option) any later version. + +This program is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with this program; if not, write to the Free Software +Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. diff --git a/m4/.gitignore b/m4/.gitignore index d5082d7..94898a0 100644 --- a/m4/.gitignore +++ b/m4/.gitignore @@ -123,3 +123,5 @@ xsize.m4 /unistd-safer.m4 /xgetcwd.m4 /xstrndup.m4 +/hash.m4 +/inttostr.m4 diff --git a/po/POTFILES.in b/po/POTFILES.in index 8c3c8f5..4d52023 100644 --- a/po/POTFILES.in +++ b/po/POTFILES.in @@ -71,6 +71,10 @@ fish/rc.c fish/reopen.c fish/tilde.c fish/time.c +fuse/dircache.c +fuse/fusexmp.c +fuse/fusexmp_fh.c +fuse/guestmount.c hivex/hivex.c hivex/hivexget.c hivex/hivexml.c -- 1.6.5.rc2