Pino Toscano
2016-May-12 15:14 UTC
[Libguestfs] [PATCH] New API: btrfs-filesystem-show (RHBZ#1164765)
Add a new API to list all the devices where a btrfs filesystem is
spanned.
---
daemon/btrfs.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++++
generator/actions.ml | 27 ++++++++++++++++++
src/MAX_PROC_NR | 2 +-
3 files changed, 106 insertions(+), 1 deletion(-)
diff --git a/daemon/btrfs.c b/daemon/btrfs.c
index 2a20cb0..62bdac7 100644
--- a/daemon/btrfs.c
+++ b/daemon/btrfs.c
@@ -2203,6 +2203,84 @@ do_btrfs_replace (const char *srcdev, const char
*targetdev,
return 0;
}
+char **
+do_btrfs_filesystem_show (const char *device)
+{
+ CLEANUP_FREE_STRINGSBUF DECLARE_STRINGSBUF (ret);
+ const size_t MAX_ARGS = 16;
+ const char *argv[MAX_ARGS];
+ size_t i = 0;
+ CLEANUP_FREE char *out = NULL;
+ CLEANUP_FREE char *err = NULL;
+ CLEANUP_FREE_STRING_LIST char **lines = NULL;
+ int r;
+
+ ADD_ARG (argv, i, str_btrfs);
+ ADD_ARG (argv, i, "filesystem");
+ ADD_ARG (argv, i, "show");
+ ADD_ARG (argv, i, device);
+ ADD_ARG (argv, i, NULL);
+
+ r = commandv (&out, &err, argv);
+ if (r == -1) {
+ reply_with_error ("%s: %s", device, err);
+ return NULL;
+ }
+
+ lines = split_lines (out);
+ if (!lines)
+ return NULL;
+
+ if (count_strings (lines) < 3) {
+ reply_with_error ("truncated output from 'btrfs filesystem
show' command");
+ return NULL;
+ }
+
+ /* Output of `btrfs filesystem show' is like:
+ *
+ * Label: none uuid: 99a1b6ba-de46-4a93-8f91-7d7685970a6c
+ * Total devices 3 FS bytes used 1.12MiB
+ * devid 1 size 10.00GiB used 2.00GiB path /dev/sda
+ * [...]
+ *
+ * or:
+ *
+ * Label: none uuid: 99a1b6ba-de46-4a93-8f91-7d7685970a6c
+ * Total devices 3 FS bytes used 1.12MiB
+ * devid 1 size 10.00GiB used 2.00GiB path /dev/sda
+ * [...]
+ * *** Some devices missing
+ */
+ for (i = 1; lines[i] != NULL; ++i) {
+ if (lines[i][0] == 0)
+ continue;
+ if (STRPREFIX (lines[i], "Label: "))
+ continue;
+ else if (STRPREFIX (lines[i], "\tTotal devices "))
+ continue;
+ else if (STRPREFIX (lines[i], "\tdevid ")) {
+ const char *p = strstr (lines[i], " path ");
+ const char *end;
+ if (!p)
+ continue;
+
+ p += strlen (" path ");
+ end = strchrnul (p, ' ');
+ add_sprintf (&ret, "%.*s", (int) (end - p), p);
+ } else if (STRPREFIX (lines[i], "\t*** Some devices missing")) {
+ reply_with_error_errno (ENODEV, "%s: missing devices", device);
+ return NULL;
+ } else {
+ reply_with_error ("unrecognized line in output from 'btrfs
filesystem show': %s", lines[i]);
+ return NULL;
+ }
+ }
+
+ end_stringsbuf (&ret);
+
+ return take_stringsbuf (&ret);
+}
+
/* btrfs command add a new command
* inspect-internal min-dev-size <path>
* since v4.2
diff --git a/generator/actions.ml b/generator/actions.ml
index e5cb939..3566371 100644
--- a/generator/actions.ml
+++ b/generator/actions.ml
@@ -12958,6 +12958,33 @@ and save it as F<filename> on the local machine.
This allows to download deleted or inaccessible files." };
+ { defaults with
+ name = "btrfs_filesystem_show"; added = (1, 33, 29);
+ style = RStringList "devices", [Device "device"], [];
+ proc_nr = Some 465;
+ optional = Some "btrfs"; camel_name =
"BTRFSFilesystemsShow";
+ tests = [
+ InitScratchFS, Always, TestLastFail (
+ [["btrfs_filesystem_show"; "/dev/sdb"]]), [];
+ InitPartition, Always, TestResult (
+ [["mkfs_btrfs"; "/dev/sda1"; "";
""; "NOARG"; ""; "NOARG";
"NOARG"; ""; ""];
+ ["btrfs_filesystem_show"; "/dev/sda1"]],
+ "is_string_list (ret, 1, \"/dev/sda1\")"), [];
+ InitEmpty, Always, TestResult (
+ [["part_init"; "/dev/sda"; "mbr"];
+ ["part_add"; "/dev/sda"; "p";
"64"; "2047999"];
+ ["part_add"; "/dev/sda"; "p";
"2048000"; "4095999"];
+ ["mkfs_btrfs"; "/dev/sda1 /dev/sda2";
""; ""; "NOARG"; ""; "NOARG";
"NOARG"; ""; ""];
+ ["btrfs_filesystem_show"; "/dev/sda1"]],
+ "is_string_list (ret, 2, \"/dev/sda1\",
\"/dev/sda2\")"), [];
+ ];
+ shortdesc = "list devices for btrfs filesystem";
+ longdesc = "\
+Show all the devices where the filesystems in C<device> is spanned over.
+
+If not all the devices for the filesystems are present, then this function
+fails and the C<errno> is set to C<ENODEV>." };
+
]
(* Non-API meta-commands available only in guestfish.
diff --git a/src/MAX_PROC_NR b/src/MAX_PROC_NR
index 3bb8a49..073c57b 100644
--- a/src/MAX_PROC_NR
+++ b/src/MAX_PROC_NR
@@ -1 +1 @@
-464
+465
--
2.5.5
Richard W.M. Jones
2016-May-12 15:20 UTC
Re: [Libguestfs] [PATCH] New API: btrfs-filesystem-show (RHBZ#1164765)
On Thu, May 12, 2016 at 05:14:50PM +0200, Pino Toscano wrote:> Add a new API to list all the devices where a btrfs filesystem is > spanned. > --- > daemon/btrfs.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++++ > generator/actions.ml | 27 ++++++++++++++++++ > src/MAX_PROC_NR | 2 +- > 3 files changed, 106 insertions(+), 1 deletion(-)Looks reasonable. I wonder if we should make more of a push to get btrfs upstream to implement a JSON mode. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-df lists disk usage of guests without needing to install any software inside the virtual machine. Supports Linux and Windows. http://people.redhat.com/~rjones/virt-df/