Re: [Libguestfs] [PATCH 2/2] lib: Add API for reading the "name" field for a drive

It is likely this field was never used. Repurpose it as a general scratchpad for callers to use to save some per-drive data. Fixes: https://github.com/libguestfs/libguestfs/issues/80 --- generator/actions_core.ml | 30 ++++++++++++++++++++++++++++-- lib/drives.c | 20 ++++++++++++++++++++ tests/c-api/tests-main.c | 4 +++- 3 files changed, 51 insertions(+), 3 deletions(-) diff --git a/generator/actions_core.ml b/generator/actions_core.ml index ce9ee39cca..44b0c22f29 100644 --- a/generator/actions_core.ml +++ b/generator/actions_core.ml @@ -263,8 +263,9 @@ deprecated C<guestfs_add_drive_with_if> call (q.v.) =item C<name> -This field used to be passed as a hint for guest inspection, but -it is no longer used. +This is an arbitrary string. If you pass in a string here, you +can read it back by calling C<guestfs_get_drive_name>. It is +not used by libguestfs itself. =item C<label> @@ -1507,6 +1508,31 @@ This call is used by L<virt-rescue(1)> to write directly to appliance console (for passing through keystrokes). It should not normally be used by other libguestfs users." }; + { defaults with + name = "get_drive_name"; added = (1, 49, 1); + style = RString (RPlainString, "name"), [Int "index"], []; + blocking = false; + tests = [ + InitEmpty, Always, TestResult ( + [["get_drive_name"; "0"]], "STREQ (ret, \"test\")"), []; + InitEmpty, Always, TestLastFail ( + [["get_drive_name"; "1"]]), []; + InitEmpty, Always, TestLastFail ( + [["get_drive_name"; "99"]]), []; + ]; + shortdesc = "get the drive name"; + longdesc = "\ +Return the optional C<name> field passed to C<guestfs_add_drive_opts> +when n'th drive C<index> was added. + +If there is no C<name> field associated with the drive +then this function returns an error, with error code C<ESRCH>. + +If you only have a device name and not an index, you can call +C<guestfs_device_index>. If what you want instead is the +drive name as it appears to libguestfs, there is no function +for that, instead use C<\"/dev/sda\">, C<\"/dev/sdb\"> etc." }; + ] let daemon_functions = [ diff --git a/lib/drives.c b/lib/drives.c index fd95308d2d..0da730c734 100644 --- a/lib/drives.c +++ b/lib/drives.c @@ -31,6 +31,7 @@ #include <netdb.h> #include <arpa/inet.h> #include <assert.h> +#include <errno.h> #include <libintl.h> #include "c-ctype.h" @@ -594,6 +595,25 @@ guestfs_int_free_drives (guestfs_h *g) g->nr_drives = 0; } +char * +guestfs_impl_get_drive_name (guestfs_h *g, int i) +{ + const char *name; + + if (i < 0 || i > g->nr_drives) {

+ guestfs_int_error_errno (g, EINVAL, _("drive index out of range")); + return NULL; + } + + name = g->drives[i]->name;

/* Array of drives added by add-drive* APIs. * * Before launch this list can be empty or contain some drives. * * During launch, a dummy slot may be added which represents the * slot taken up by the appliance drive. * * During shutdown, this list is deleted, so that each launch gets a * fresh set of drives (however callers: don't do this, create a new * handle each time). * * Always use ITER_DRIVES macro to iterate over this list! */ struct drive **drives; size_t nr_drives; #define ITER_DRIVES(g,i,drv) \ for (i = 0; i < (g)->nr_drives; ++i) \ if (((drv) = (g)->drives[i]) != NULL)

+ if (!name) { + guestfs_int_error_errno (g, ESRCH, _("drive does not have a name")); + return NULL; + } + + return safe_strdup (g, name); +} + /** * Check string parameter matches regular expression * C<^[-_[:alnum:]]+$> (in C locale). diff --git a/tests/c-api/tests-main.c b/tests/c-api/tests-main.c index 9e01e4a3dc..a0aad1735d 100644 --- a/tests/c-api/tests-main.c +++ b/tests/c-api/tests-main.c @@ -431,7 +431,9 @@ create_handle (void) exit (EXIT_FAILURE); } - if (guestfs_add_drive_scratch (g, INT64_C(2)*1024*1024*1024, -1) == -1) { + if (guestfs_add_drive_scratch (g, INT64_C(2)*1024*1024*1024, + GUESTFS_ADD_DRIVE_SCRATCH_NAME, "test", + -1) == -1) { printf ("FAIL: guestfs_add_drive_scratch\n"); exit (EXIT_FAILURE); }