Libguestfs - Mar 2015 - [PATCH 1/2] New API: btrfs_filesystem_show

Chen Hanxiao (2):
  New API: btrfs_filesystem_show
  New API: btrfs_filesystem_show_all

 daemon/btrfs.c       | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++
 generator/actions.ml | 21 +++++++++++++++++++++
 src/MAX_PROC_NR      |  2 +-
 3 files changed, 73 insertions(+), 1 deletion(-)

-- 
2.1.0

Signed-off-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com>
---
 daemon/btrfs.c       | 26 ++++++++++++++++++++++++++
 generator/actions.ml | 10 ++++++++++
 src/MAX_PROC_NR      |  2 +-
 3 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/daemon/btrfs.c b/daemon/btrfs.c
index d4b3207..df2fbf6 100644
--- a/daemon/btrfs.c
+++ b/daemon/btrfs.c
@@ -1608,6 +1608,32 @@ do_btrfs_filesystem_defragment (const char *path, int
flush, const char *compres
   return 0;
 }
 
+char *
+do_btrfs_filesystem_show (const char *device)
+{
+  const size_t MAX_ARGS = 64;
+  const char *argv[MAX_ARGS];
+  size_t i = 0;
+  CLEANUP_FREE char *err = NULL;
+  char *out = 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);
+    free(out);
+    return NULL;
+  }
+
+  return out;
+}
+
 int
 do_btrfs_rescue_chunk_recover (const char *device)
 {
diff --git a/generator/actions.ml b/generator/actions.ml
index 9f32cb5..e6cd8f2 100644
--- a/generator/actions.ml
+++ b/generator/actions.ml
@@ -12522,6 +12522,16 @@ This will Enable extended inode refs." };
     longdesc = "\
 This enable skinny metadata extent refs." };
 
+  { defaults with
+    name = "btrfs_filesystem_show";
+    style = RString "output", [Device "device"], [];
+    proc_nr = Some 453;
+    optional = Some "btrfs"; camel_name =
"BTRFSFilesystemShow";
+    test_excuse = "can't be tested becasue output will vary from each
mkfs.btrfs";
+    shortdesc = "show btrfs filesystem with some additional info";
+    longdesc = "\
+This show btrfs filesystem with some additional info." };
+
 ]
 
 (* Non-API meta-commands available only in guestfish.
diff --git a/src/MAX_PROC_NR b/src/MAX_PROC_NR
index 8670c73..534b992 100644
--- a/src/MAX_PROC_NR
+++ b/src/MAX_PROC_NR
@@ -1 +1 @@
-452
+453
-- 
2.1.0

Signed-off-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com>
---
 daemon/btrfs.c       | 25 +++++++++++++++++++++++++
 generator/actions.ml | 11 +++++++++++
 src/MAX_PROC_NR      |  2 +-
 3 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/daemon/btrfs.c b/daemon/btrfs.c
index df2fbf6..1c040a4 100644
--- a/daemon/btrfs.c
+++ b/daemon/btrfs.c
@@ -1634,6 +1634,31 @@ do_btrfs_filesystem_show (const char *device)
   return out;
 }
 
+char *
+do_btrfs_filesystem_show_all (void)
+{
+  const size_t MAX_ARGS = 64;
+  const char *argv[MAX_ARGS];
+  size_t i = 0;
+  CLEANUP_FREE char *err = NULL;
+  char *out = NULL;
+  int r;
+
+  ADD_ARG (argv, i, str_btrfs);
+  ADD_ARG (argv, i, "filesystem");
+  ADD_ARG (argv, i, "show");
+  ADD_ARG (argv, i, NULL);
+
+  r = commandv (&out, &err, argv);
+  if (r == -1) {
+    reply_with_error ("%s", err);
+    free(out);
+    return NULL;
+  }
+
+  return out;
+}
+
 int
 do_btrfs_rescue_chunk_recover (const char *device)
 {
diff --git a/generator/actions.ml b/generator/actions.ml
index e6cd8f2..db20875 100644
--- a/generator/actions.ml
+++ b/generator/actions.ml
@@ -12532,6 +12532,17 @@ This enable skinny metadata extent refs." };
     longdesc = "\
 This show btrfs filesystem with some additional info." };
 
+  { defaults with
+    name = "btrfs_filesystem_show_all";
+    style = RString "output", [], [];
+    (*style = RString "output", [], [OString "device"];*)
+    proc_nr = Some 454;
+    optional = Some "btrfs"; camel_name =
"BTRFSFilesystemShowAll";
+    test_excuse = "can't be tested becasue output will vary from each
mkfs.btrfs";
+    shortdesc = "show all devices run btrfs filesystem with some
additional info";
+    longdesc = "\
+This show all devices run btrfs filesystem with some additional info." };
+
 ]
 
 (* Non-API meta-commands available only in guestfish.
diff --git a/src/MAX_PROC_NR b/src/MAX_PROC_NR
index 534b992..515f19a 100644
--- a/src/MAX_PROC_NR
+++ b/src/MAX_PROC_NR
@@ -1 +1 @@
-453
+454
-- 
2.1.0

AFAICT this API doesn't work:

  $ ./run guestfish -N fs:btrfs btrfs-filesystem-show /dev/sda1
  libguestfs: error: btrfs_filesystem_show: /dev/sda1: 

When I tried the btrfs-filesystem-show-all API, I see a lot of
structure in the output:

  $ ./run guestfish -N fs:btrfs btrfs-filesystem-show-all
  Label: none  uuid: f7754d86-baa1-40e7-a563-46976e81d64c
         Total devices 1 FS bytes used 28.00KiB
         devid    1 size 99.88MiB used 12.00MiB path /dev/sda1
  
  Btrfs v3.18

Usually we should try to turn that text into structs, otherwise every
consumer of libguestfs has to write parsing code themselves.

*However* in this case I'm having a hard time understanding why anyone
would want to use the API.  Most likely if they were debugging a btrfs
problem, they'd be using 'virt-rescue' and would be able to run
arbitrary commands.  Some of the other information, like UUID and
label is available through other APIs (eg. get-uuid).  Other
information like the layout of devices could be modelled with some
very complex structs on the libguestfs side, but does anyone need
this?

Rich.

-- 
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