6:20 a.m.
This patch changes appliance search using paths with multiple directories. Now
all appliance checks will be done separately for each directory. For example
if the path LIBGUESTFS_PATH=/a:/b:/c, then all applainces are searched first in
/a, then in /b and then in /c. It allows to flexibly configure the libguestfs
to interact with different appliances.
Signed-off-by: Pavel Butsykin <pbutsykin(a)virtuozzo.com>
---
lib/appliance.c | 231 ++++++++++++++++++++++++++------------------------------
1 file changed, 108 insertions(+), 123 deletions(-)
diff --git a/lib/appliance.c b/lib/appliance.c
index f12918573..c21525961 100644
--- a/lib/appliance.c
+++ b/lib/appliance.c
@@ -37,18 +37,23 @@
#include "guestfs.h"
#include "guestfs-internal.h"
+typedef struct appliance_files {
+ char *kernel;
+ char *initrd;
+ char *image;
+} appliance_files;
+
/* Old-style appliance is going to be obsoleted. */
static const char kernel_name[] = "vmlinuz." host_cpu;
static const char initrd_name[] = "initramfs." host_cpu ".img";
-static int build_appliance (guestfs_h *g, char **kernel, char **initrd, char
**appliance);
-static int find_path (guestfs_h *g, int (*pred) (guestfs_h *g, const char *pelem, void
*data), void *data, char **pelem);
+static int search_appliance (guestfs_h *g, appliance_files *appliance);
static int dir_contains_file (guestfs_h *g, const char *dir, const char *file);
static int dir_contains_files (guestfs_h *g, const char *dir, ...);
static int contains_old_style_appliance (guestfs_h *g, const char *path, void *data);
static int contains_fixed_appliance (guestfs_h *g, const char *path, void *data);
static int contains_supermin_appliance (guestfs_h *g, const char *path, void *data);
-static int build_supermin_appliance (guestfs_h *g, const char *supermin_path, char
**kernel, char **initrd, char **appliance);
+static int build_supermin_appliance (guestfs_h *g, const char *supermin_path,
appliance_files *appliance);
static int run_supermin_build (guestfs_h *g, const char *lockfile, const char
*appliancedir, const char *supermin_path);
/**
@@ -59,12 +64,12 @@ static int run_supermin_build (guestfs_h *g, const char *lockfile,
const char *a
* appliances, or using either a fixed or old-style appliance.
*
* The return value is C<0> = good, C<-1> = error. Returned in
- * C<*kernel> will be the name of the kernel to use, C<*initrd> the
- * name of the initrd, C<*appliance> the name of the ext2 root
- * filesystem. C<*appliance> can be C<NULL>, meaning that we are
- * using an old-style (non-ext2) appliance. All three strings must be
- * freed by the caller. However the referenced files themselves must
- * I<not> be deleted.
+ * C<appliance.kernel> will be the name of the kernel to use,
+ * C<appliance.initrd> the name of the initrd, C<appliance.image> the name
of
+ * the ext2 root filesystem. C<appliance.image> can be C<NULL>, meaning
that
+ * we are using an old-style (non-ext2) appliance. All three strings must be
+ * freed by the caller. However the referenced files themselves must I<not> be
+ * deleted.
*
* The process is as follows:
*
@@ -72,9 +77,8 @@ static int run_supermin_build (guestfs_h *g, const char *lockfile, const
char *a
*
* =item 1.
*
- * Look for the first element of C<g-E<gt>path> which contains a
- * supermin appliance skeleton. If no element has this, skip straight
- * to step 3.
+ * Look in C<path> which contains a supermin appliance skeleton. If no element
+ * has this, skip straight to step 3.
*
* =item 2.
*
@@ -83,13 +87,12 @@ static int run_supermin_build (guestfs_h *g, const char *lockfile,
const char *a
*
* =item 3.
*
- * Check each element of C<g-E<gt>path>, looking for a fixed
- * appliance. If one is found, return it.
+ * Check C<path>, looking for a fixed appliance. If one is found, return it.
*
* =item 4.
*
- * Check each element of C<g-E<gt>path>, looking for an old-style
- * appliance. If one is found, return it.
+ * Check C<path>, looking for an old-style appliance. If one is found,
+ * return it.
*
* =back
*
@@ -112,74 +115,116 @@ guestfs_int_build_appliance (guestfs_h *g,
char **initrd_rtn,
char **appliance_rtn)
{
- char *kernel = NULL, *initrd = NULL, *appliance = NULL;
- if (build_appliance (g, &kernel, &initrd, &appliance) == -1)
+ appliance_files appliance;
+
+ if (search_appliance (g, &appliance) != 1)
return -1;
/* Don't assign these until we know we're going to succeed, to avoid
* the caller double-freeing (RHBZ#983218).
*/
- *kernel_rtn = kernel;
- *initrd_rtn = initrd;
- *appliance_rtn = appliance;
+ *kernel_rtn = appliance.kernel;
+ *initrd_rtn = appliance.initrd;
+ *appliance_rtn = appliance.image;
return 0;
}
+/**
+ * Check C<path>, looking for one of appliances: supermin appliance,
+ * fixed appliance or old-style appliance. If one of the fixed appliances is
+ * found, return it. If the supermin appliance skeleton is found, build and
+ * return appliance.
+ *
+ * Return values:
+ *
+ * 1 = appliance is found, returns C<appliance>,
+ * 0 = appliance not found,
+ * -1 = error which aborts the launch process.
+ */
static int
-build_appliance (guestfs_h *g,
- char **kernel,
- char **initrd,
- char **appliance)
+locate_or_build_appliance (guestfs_h *g,
+ appliance_files *appliance,
+ const char *path)
{
int r;
- CLEANUP_FREE char *supermin_path = NULL;
- CLEANUP_FREE char *path = NULL;
/* Step (1). */
- r = find_path (g, contains_supermin_appliance, NULL, &supermin_path);
- if (r == -1)
- return -1;
-
- if (r == 1)
+ r = contains_supermin_appliance(g, path, NULL);
+ if (r == 1) {
/* Step (2): build supermin appliance. */
- return build_supermin_appliance (g, supermin_path,
- kernel, initrd, appliance);
+ r = build_supermin_appliance (g, path, appliance);
+ return r < 0 ? r : 1;
+ }
/* Step (3). */
- r = find_path (g, contains_fixed_appliance, NULL, &path);
- if (r == -1)
- return -1;
-
+ r = contains_fixed_appliance (g, path, NULL);
if (r == 1) {
const size_t len = strlen (path);
- *kernel = safe_malloc (g, len + 6 /* "kernel" */ + 2);
- *initrd = safe_malloc (g, len + 6 /* "initrd" */ + 2);
- *appliance = safe_malloc (g, len + 4 /* "root" */ + 2);
- sprintf (*kernel, "%s/kernel", path);
- sprintf (*initrd, "%s/initrd", path);
- sprintf (*appliance, "%s/root", path);
- return 0;
+ appliance->kernel = safe_malloc (g, len + 6 /* "kernel" */ + 2);
+ appliance->initrd = safe_malloc (g, len + 6 /* "initrd" */ + 2);
+ appliance->image = safe_malloc (g, len + 4 /* "root" */ + 2);
+ sprintf (appliance->kernel, "%s/kernel", path);
+ sprintf (appliance->initrd, "%s/initrd", path);
+ sprintf (appliance->image, "%s/root", path);
+ return 1;
}
/* Step (4). */
- r = find_path (g, contains_old_style_appliance, NULL, &path);
- if (r == -1)
- return -1;
-
+ r = contains_old_style_appliance (g, path, NULL);
if (r == 1) {
const size_t len = strlen (path);
- *kernel = safe_malloc (g, len + strlen (kernel_name) + 2);
- *initrd = safe_malloc (g, len + strlen (initrd_name) + 2);
- sprintf (*kernel, "%s/%s", path, kernel_name);
- sprintf (*initrd, "%s/%s", path, initrd_name);
- *appliance = NULL;
- return 0;
+ appliance->kernel = safe_malloc (g, len + strlen (kernel_name) + 2);
+ appliance->initrd = safe_malloc (g, len + strlen (initrd_name) + 2);
+ sprintf (appliance->kernel, "%s/%s", path, kernel_name);
+ sprintf (appliance->initrd, "%s/%s", path, initrd_name);
+ appliance->image = NULL;
+ return 1;
}
+ return 0;
+}
+
+
+/**
+ * Search elements of C<g-E<gt>path>, returning the first C<appliance>
element
+ * which matches the predicate function C<locate_or_build_appliance>.
+ *
+ * Return values:
+ *
+ * 1 = a path element matched, returns C<appliance>,
+ * 0 = no path element matched,
+ * -1 = error which aborts the launch process.
+ */
+static int
+search_appliance (guestfs_h *g, appliance_files *appliance)
+{
+ const char *pelem = g->path;
+
+ /* Note that if g->path is an empty string, we want to check the
+ * current directory (for backwards compatibility with
+ * libguestfs < 1.5.4).
+ */
+ do {
+ size_t len = strcspn (pelem, PATH_SEPARATOR);
+ /* Empty element or "." means current directory. */
+ char *path = (len == 0) ? safe_strdup (g, ".") :
+ safe_strndup (g, pelem, len);
+ int r = locate_or_build_appliance (g, appliance, path);
+ free (path);
+ if (r != 0)
+ return r; /* error or predicate matched */
+
+ if (pelem[len] == PATH_SEPARATOR[0])
+ pelem += len + 1;
+ else
+ pelem += len;
+ } while (*pelem);
+
+ /* Predicate didn't match on any path element. */
error (g, _("cannot find any suitable libguestfs supermin, fixed or old-style
appliance on LIBGUESTFS_PATH (search path: %s)"),
g->path);
- return -1;
+ return 0;
}
static int
@@ -211,8 +256,7 @@ contains_supermin_appliance (guestfs_h *g, const char *path, void
*data)
static int
build_supermin_appliance (guestfs_h *g,
const char *supermin_path,
- char **kernel, char **initrd,
- char **appliance)
+ appliance_files *appliance)
{
CLEANUP_FREE char *cachedir = NULL, *lockfile = NULL, *appliancedir = NULL;
@@ -234,13 +278,13 @@ build_supermin_appliance (guestfs_h *g,
debug (g, "finished building supermin appliance");
/* Return the appliance filenames. */
- *kernel = safe_asprintf (g, "%s/kernel", appliancedir);
- *initrd = safe_asprintf (g, "%s/initrd", appliancedir);
- *appliance = safe_asprintf (g, "%s/root", appliancedir);
+ appliance->kernel = safe_asprintf (g, "%s/kernel", appliancedir);
+ appliance->initrd = safe_asprintf (g, "%s/initrd", appliancedir);
+ appliance->image = safe_asprintf (g, "%s/root", appliancedir);
/* Touch the files so they don't get deleted (as they are in /var/tmp). */
- (void) utimes (*kernel, NULL);
- (void) utimes (*initrd, NULL);
+ (void) utimes (appliance->kernel, NULL);
+ (void) utimes (appliance->initrd, NULL);
/* Checking backend != "uml" is a big hack. UML encodes the mtime
* of the original backing file (in this case, the appliance) in the
@@ -255,7 +299,7 @@ build_supermin_appliance (guestfs_h *g,
* XXX
*/
if (STRNEQ (g->backend, "uml"))
- (void) utimes (*appliance, NULL);
+ (void) utimes (appliance->image, NULL);
return 0;
}
@@ -315,65 +359,6 @@ run_supermin_build (guestfs_h *g,
}
/**
- * Search elements of C<g-E<gt>path>, returning the first path element
- * which matches the predicate function C<pred>.
- *
- * Function C<pred> must return a true or false value. If it returns
- * C<-1> then the entire search is aborted.
- *
- * Return values:
- *
- * 1 = a path element matched, it is returned in *pelem_ret and must be
- * freed by the caller,
- * 0 = no path element matched, *pelem_ret is set to NULL, or
- * -1 = error which aborts the launch process
- */
-static int
-find_path (guestfs_h *g,
- int (*pred) (guestfs_h *g, const char *pelem, void *data),
- void *data,
- char **pelem_ret)
-{
- size_t len;
- int r;
- const char *pelem = g->path;
-
- /* Note that if g->path is an empty string, we want to check the
- * current directory (for backwards compatibility with
- * libguestfs < 1.5.4).
- */
- do {
- len = strcspn (pelem, PATH_SEPARATOR);
-
- /* Empty element or "." means current directory. */
- if (len == 0)
- *pelem_ret = safe_strdup (g, ".");
- else
- *pelem_ret = safe_strndup (g, pelem, len);
-
- r = pred (g, *pelem_ret, data);
- if (r == -1) {
- free (*pelem_ret);
- return -1;
- }
-
- if (r != 0) /* predicate matched */
- return 1;
-
- free (*pelem_ret);
-
- if (pelem[len] == PATH_SEPARATOR[0])
- pelem += len + 1;
- else
- pelem += len;
- } while (*pelem);
-
- /* Predicate didn't match on any path element. */
- *pelem_ret = NULL;
- return 0;
-}
-
-/**
* Returns true iff C<file> is contained in C<dir>.
*/
static int
--
2.11.0