Libguestfs - Nov 2014 - [PATCH 0/6] btrfs support part1: subvolume commands

Hi,

This is the part1 of improving btrfs support. This series adds missing
parameters to btrfs_subvolume_snapshot and btrfs_subvolume_create, and
adds two new API btrfs_subvolume_get_default and btrfs_subvolume_show.

Other parts will follow.

Regards,
Hu


Hu Tao (6):
  btrfs: correct words about subvolume and snapshot
  btrfs: add optional parameter `ro' to btrfs_subvolume_snapshot
  btrfs: add optional parameter `qgroupid' to btrfs_subvolume_snapshot
  btrfs: add optional parameter `qgroupid' to btrfs_subvolume_create
  New API: btrfs_subvolume_get_default
  New API: btrfs_subvolume_show

 daemon/btrfs.c       | 232 ++++++++++++++++++++++++++++++++++++++++++++++++++-
 generator/actions.ml |  44 +++++++---
 src/MAX_PROC_NR      |   2 +-
 3 files changed, 263 insertions(+), 15 deletions(-)

-- 
1.9.3

btrfs_subvolume_create creates only subvolumes. btrfs_subvolume_delete
deletes subvolumes or snapshots.

Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
---
 generator/actions.ml | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/generator/actions.ml b/generator/actions.ml
index 89332f5..fe492e6 100644
--- a/generator/actions.ml
+++ b/generator/actions.ml
@@ -10248,19 +10248,19 @@ of the snapshot, in the form
C</path/to/dest/name>." };
          ["btrfs_subvolume_create"; "/test1"];
          ["btrfs_subvolume_delete"; "/test1"]]), []
     ];
-    shortdesc = "delete a btrfs snapshot";
+    shortdesc = "delete a btrfs subvolume or snapshot";
     longdesc = "\
-Delete the named btrfs subvolume." };
+Delete the named btrfs subvolume or snapshot." };
 
   { defaults with
     name = "btrfs_subvolume_create";
     style = RErr, [Pathname "dest"], [];
     proc_nr = Some 324;
     optional = Some "btrfs"; camel_name =
"BTRFSSubvolumeCreate";
-    shortdesc = "create a btrfs snapshot";
+    shortdesc = "create a btrfs subvolume";
     longdesc = "\
 Create a btrfs subvolume.  The C<dest> argument is the destination
-directory and the name of the snapshot, in the form
C</path/to/dest/name>." };
+directory and the name of the subvolume, in the form
C</path/to/dest/name>." };
 
   { defaults with
     name = "btrfs_subvolume_list";
-- 
1.9.3

Parameter `ro' is for creating readonly btrfs snapshot.

Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
---
 daemon/btrfs.c       | 11 ++++++++++-
 generator/actions.ml |  4 ++--
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/daemon/btrfs.c b/daemon/btrfs.c
index 7a4d43d..b630bce 100644
--- a/daemon/btrfs.c
+++ b/daemon/btrfs.c
@@ -208,7 +208,7 @@ do_mkfs_btrfs (char *const *devices,
 }
 
 int
-do_btrfs_subvolume_snapshot (const char *source, const char *dest)
+do_btrfs_subvolume_snapshot (const char *source, const char *dest, int ro)
 {
   const size_t MAX_ARGS = 64;
   const char *argv[MAX_ARGS];
@@ -231,6 +231,15 @@ do_btrfs_subvolume_snapshot (const char *source, const char
*dest)
   ADD_ARG (argv, i, str_btrfs);
   ADD_ARG (argv, i, "subvolume");
   ADD_ARG (argv, i, "snapshot");
+
+  /* Optional arguments. */
+  if (!(optargs_bitmask & GUESTFS_BTRFS_SUBVOLUME_SNAPSHOT_RO_BITMASK))
+    ro = 0;
+
+  if (ro) {
+    ADD_ARG (argv, i, "-r");
+  }
+
   ADD_ARG (argv, i, source_buf);
   ADD_ARG (argv, i, dest_buf);
   ADD_ARG (argv, i, NULL);
diff --git a/generator/actions.ml b/generator/actions.ml
index fe492e6..850e58d 100644
--- a/generator/actions.ml
+++ b/generator/actions.ml
@@ -10217,7 +10217,7 @@ See C<guestfs_get_e2generation>." };
 
   { defaults with
     name = "btrfs_subvolume_snapshot";
-    style = RErr, [Pathname "source"; Pathname "dest"], [];
+    style = RErr, [Pathname "source"; Pathname "dest"],
[OBool "ro"];
     proc_nr = Some 322;
     optional = Some "btrfs"; camel_name =
"BTRFSSubvolumeSnapshot";
     tests = [
@@ -10228,7 +10228,7 @@ See C<guestfs_get_e2generation>." };
          ["btrfs_subvolume_create"; "/test1"];
          ["btrfs_subvolume_create"; "/test2"];
          ["btrfs_subvolume_create"; "/dir/test3"];
-         ["btrfs_subvolume_snapshot"; "/dir/test3";
"/dir/test4"]]), []
+         ["btrfs_subvolume_snapshot"; "/dir/test3";
"/dir/test5"; "true"]]), []
     ];
     shortdesc = "create a writable btrfs snapshot";
     longdesc = "\
-- 
1.9.3

Parameter `qgroupid' is for adding the created snapshot to a qgroup.

Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
---
 daemon/btrfs.c       | 8 +++++++-
 generator/actions.ml | 5 +++--
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/daemon/btrfs.c b/daemon/btrfs.c
index b630bce..a20afca 100644
--- a/daemon/btrfs.c
+++ b/daemon/btrfs.c
@@ -208,7 +208,8 @@ do_mkfs_btrfs (char *const *devices,
 }
 
 int
-do_btrfs_subvolume_snapshot (const char *source, const char *dest, int ro)
+do_btrfs_subvolume_snapshot (const char *source, const char *dest, int ro,
+                             const char *qgroupid)
 {
   const size_t MAX_ARGS = 64;
   const char *argv[MAX_ARGS];
@@ -240,6 +241,11 @@ do_btrfs_subvolume_snapshot (const char *source, const char
*dest, int ro)
     ADD_ARG (argv, i, "-r");
   }
 
+  if (optargs_bitmask & GUESTFS_BTRFS_SUBVOLUME_SNAPSHOT_QGROUPID_BITMASK)
{
+    ADD_ARG (argv, i, "-i");
+    ADD_ARG (argv, i, qgroupid);
+  }
+
   ADD_ARG (argv, i, source_buf);
   ADD_ARG (argv, i, dest_buf);
   ADD_ARG (argv, i, NULL);
diff --git a/generator/actions.ml b/generator/actions.ml
index 850e58d..30b839c 100644
--- a/generator/actions.ml
+++ b/generator/actions.ml
@@ -10217,7 +10217,7 @@ See C<guestfs_get_e2generation>." };
 
   { defaults with
     name = "btrfs_subvolume_snapshot";
-    style = RErr, [Pathname "source"; Pathname "dest"],
[OBool "ro"];
+    style = RErr, [Pathname "source"; Pathname "dest"],
[OBool "ro"; OString "qgroupid"];
     proc_nr = Some 322;
     optional = Some "btrfs"; camel_name =
"BTRFSSubvolumeSnapshot";
     tests = [
@@ -10228,7 +10228,8 @@ See C<guestfs_get_e2generation>." };
          ["btrfs_subvolume_create"; "/test1"];
          ["btrfs_subvolume_create"; "/test2"];
          ["btrfs_subvolume_create"; "/dir/test3"];
-         ["btrfs_subvolume_snapshot"; "/dir/test3";
"/dir/test5"; "true"]]), []
+         ["btrfs_subvolume_snapshot"; "/dir/test3";
"/dir/test5"; "true"; "NOARG"];
+         ["btrfs_subvolume_snapshot"; "/dir/test3";
"/dir/test6"; ""; "0/1000"]]), []
     ];
     shortdesc = "create a writable btrfs snapshot";
     longdesc = "\
-- 
1.9.3

Parameter `qgroupid' is for adding the created subvolume to a qgroup.

Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
---
 daemon/btrfs.c       | 10 +++++++++-
 generator/actions.ml | 15 ++++++++-------
 2 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/daemon/btrfs.c b/daemon/btrfs.c
index a20afca..0f525fa 100644
--- a/daemon/btrfs.c
+++ b/daemon/btrfs.c
@@ -291,7 +291,7 @@ do_btrfs_subvolume_delete (const char *subvolume)
 }
 
 int
-do_btrfs_subvolume_create (const char *dest)
+do_btrfs_subvolume_create (const char *dest, const char *qgroupid)
 {
   const size_t MAX_ARGS = 64;
   const char *argv[MAX_ARGS];
@@ -309,6 +309,14 @@ do_btrfs_subvolume_create (const char *dest)
   ADD_ARG (argv, i, str_btrfs);
   ADD_ARG (argv, i, "subvolume");
   ADD_ARG (argv, i, "create");
+
+  /* Optional arguments. */
+  if (optargs_bitmask & GUESTFS_BTRFS_SUBVOLUME_CREATE_QGROUPID_BITMASK) {
+    ADD_ARG (argv, i, "-i");
+    ADD_ARG (argv, i, qgroupid);
+  }
+
+
   ADD_ARG (argv, i, dest_buf);
   ADD_ARG (argv, i, NULL);
 
diff --git a/generator/actions.ml b/generator/actions.ml
index 30b839c..1c1fcff 100644
--- a/generator/actions.ml
+++ b/generator/actions.ml
@@ -10225,9 +10225,9 @@ See C<guestfs_get_e2generation>." };
         [["mkfs_btrfs"; "/dev/sda1"; "";
""; "NOARG"; ""; "NOARG";
"NOARG"; ""; ""];
          ["mount"; "/dev/sda1"; "/"];
          ["mkdir"; "/dir"];
-         ["btrfs_subvolume_create"; "/test1"];
-         ["btrfs_subvolume_create"; "/test2"];
-         ["btrfs_subvolume_create"; "/dir/test3"];
+         ["btrfs_subvolume_create"; "/test1";
"NOARG"];
+         ["btrfs_subvolume_create"; "/test2";
"NOARG"];
+         ["btrfs_subvolume_create"; "/dir/test3";
"NOARG"];
          ["btrfs_subvolume_snapshot"; "/dir/test3";
"/dir/test5"; "true"; "NOARG"];
          ["btrfs_subvolume_snapshot"; "/dir/test3";
"/dir/test6"; ""; "0/1000"]]), []
     ];
@@ -10246,7 +10246,7 @@ of the snapshot, in the form
C</path/to/dest/name>." };
       InitPartition, Always, TestRun (
         [["mkfs_btrfs"; "/dev/sda1"; "";
""; "NOARG"; ""; "NOARG";
"NOARG"; ""; ""];
          ["mount"; "/dev/sda1"; "/"];
-         ["btrfs_subvolume_create"; "/test1"];
+         ["btrfs_subvolume_create"; "/test1";
"NOARG"];
          ["btrfs_subvolume_delete"; "/test1"]]), []
     ];
     shortdesc = "delete a btrfs subvolume or snapshot";
@@ -10255,13 +10255,14 @@ Delete the named btrfs subvolume or snapshot." };
 
   { defaults with
     name = "btrfs_subvolume_create";
-    style = RErr, [Pathname "dest"], [];
+    style = RErr, [Pathname "dest"], [OString "qgroupid"];
     proc_nr = Some 324;
     optional = Some "btrfs"; camel_name =
"BTRFSSubvolumeCreate";
     shortdesc = "create a btrfs subvolume";
     longdesc = "\
 Create a btrfs subvolume.  The C<dest> argument is the destination
-directory and the name of the subvolume, in the form
C</path/to/dest/name>." };
+directory and the name of the subvolume, in the form
C</path/to/dest/name>.
+The C<qgroupid> adds the newly created subvolume to a qgroup." };
 
   { defaults with
     name = "btrfs_subvolume_list";
@@ -10295,7 +10296,7 @@ get a list of subvolumes." };
       InitPartition, Always, TestRun (
         [["mkfs_btrfs"; "/dev/sda1"; "";
""; "NOARG"; ""; "NOARG";
"NOARG"; ""; ""];
          ["mount"; "/dev/sda1"; "/"];
-         ["btrfs_subvolume_create"; "/test1"];
+         ["btrfs_subvolume_create"; "/test1";
"NOARG"];
          ["btrfs_filesystem_sync"; "/test1"];
          ["btrfs_filesystem_balance"; "/test1"]]), []
     ];
-- 
1.9.3

btrfs_subvolume_get_default is for getting the default subvolume of
a btrfs filesystem.

Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
---
 daemon/btrfs.c       | 38 ++++++++++++++++++++++++++++++++++++++
 generator/actions.ml |  9 +++++++++
 src/MAX_PROC_NR      |  2 +-
 3 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/daemon/btrfs.c b/daemon/btrfs.c
index 0f525fa..e179b57 100644
--- a/daemon/btrfs.c
+++ b/daemon/btrfs.c
@@ -549,6 +549,44 @@ do_btrfs_subvolume_set_default (int64_t id, const char *fs)
 }
 
 int
+do_btrfs_subvolume_get_default (const char *fs)
+{
+  const size_t MAX_ARGS = 64;
+  const char *argv[MAX_ARGS];
+  size_t i = 0;
+  CLEANUP_FREE char *fs_buf = NULL;
+  CLEANUP_FREE char *err = NULL;
+  CLEANUP_FREE char *out = NULL;
+  int r;
+
+  fs_buf = sysroot_path (fs);
+  if (fs_buf == NULL) {
+    reply_with_perror ("malloc");
+    return -1;
+  }
+
+  ADD_ARG (argv, i, str_btrfs);
+  ADD_ARG (argv, i, "subvolume");
+  ADD_ARG (argv, i, "get-default");
+  ADD_ARG (argv, i, fs_buf);
+  ADD_ARG (argv, i, NULL);
+
+  r = commandv (&out, &err, argv);
+  fprintf(stderr, "%s\n", out);
+  if (r == -1) {
+    reply_with_error ("%s: %s", fs, err);
+    return -1;
+  }
+  r = -1;
+  if (sscanf (out, "ID %" SCNi32, &r) != 1) {
+    reply_with_error ("%s: expected output, but got nothing",
argv[0]);
+    return -1;
+  }
+
+  return r;
+}
+
+int
 do_btrfs_filesystem_sync (const char *fs)
 {
   const size_t MAX_ARGS = 64;
diff --git a/generator/actions.ml b/generator/actions.ml
index 1c1fcff..cf96039 100644
--- a/generator/actions.ml
+++ b/generator/actions.ml
@@ -12005,6 +12005,15 @@ This is the same as the C<lstat(2)> system
call." };
     longdesc = "\
 This is the internal call which implements C<guestfs_lstatnslist>."
};
 
+  { defaults with
+    name = "btrfs_subvolume_get_default";
+    style = RInt "id", [Pathname "mountpoint"], [];
+    proc_nr = Some 424;
+    optional = Some "btrfs"; camel_name =
"BTRFSSubvolumeGetDefault";
+    shortdesc = "get the default subvolume or snapshot of a
filesystem";
+    longdesc = "\
+Get the default subvolume or snapshot of a filesystem mounted at
C<mountpoint>." };
+
 ]
 
 (* Non-API meta-commands available only in guestfish.
diff --git a/src/MAX_PROC_NR b/src/MAX_PROC_NR
index 5721413..9524ef4 100644
--- a/src/MAX_PROC_NR
+++ b/src/MAX_PROC_NR
@@ -1 +1 @@
-423
+424
-- 
1.9.3

btrfs_subvolume_show shows the detailed information of a subvolume or
snapshot.

Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
---
 daemon/btrfs.c       | 167 +++++++++++++++++++++++++++++++++++++++++++++++++++
 generator/actions.ml |   9 +++
 src/MAX_PROC_NR      |   2 +-
 3 files changed, 177 insertions(+), 1 deletion(-)

diff --git a/daemon/btrfs.c b/daemon/btrfs.c
index e179b57..36ba588 100644
--- a/daemon/btrfs.c
+++ b/daemon/btrfs.c
@@ -29,6 +29,7 @@
 #include "actions.h"
 #include "optgroups.h"
 #include "xstrtol.h"
+#include "c-ctype.h"
 
 GUESTFSD_EXT_CMD(str_btrfs, btrfs);
 GUESTFSD_EXT_CMD(str_btrfstune, btrfstune);
@@ -813,3 +814,169 @@ do_btrfs_fsck (const char *device, int64_t superblock, int
repair)
 
   return 0;
 }
+
+char **do_btrfs_subvolume_show (const char *subvolume)
+{
+  const size_t MAX_ARGS = 64;
+  const char *argv[MAX_ARGS];
+  size_t i = 0;
+  CLEANUP_FREE char *subvolume_buf = NULL;
+  CLEANUP_FREE char *err = NULL;
+  CLEANUP_FREE char *out = NULL;
+  char *p, *pend, *colon;
+  DECLARE_STRINGSBUF (ret);
+  int r;
+
+  subvolume_buf = sysroot_path (subvolume);
+  if (subvolume_buf == NULL) {
+    reply_with_perror ("malloc");
+    return NULL;
+  }
+
+  ADD_ARG (argv, i, str_btrfs);
+  ADD_ARG (argv, i, "subvolume");
+  ADD_ARG (argv, i, "show");
+  ADD_ARG (argv, i, subvolume_buf);
+  ADD_ARG (argv, i, NULL);
+
+  r = commandv (&out, &err, argv);
+  if (r == -1) {
+    reply_with_error ("%s: %s", subvolume, err);
+    return NULL;
+  }
+
+  /* Output is:
+   *
+   * /
+   *         Name:                   root
+   *         uuid:                   c875169e-cf4e-a04d-9959-b667dec36234
+   *         Parent uuid:            -
+   *         Creation time:          2014-11-13 10:13:08
+   *         Object ID:              256
+   *         Generation (Gen):       6579
+   *         Gen at creation:        5
+   *         Parent:                 5
+   *         Top Level:              5
+   *         Flags:                  -
+   *         Snapshot(s):
+   *                                 snapshots/test1
+   *                                 snapshots/test2
+   *                                 snapshots/test3
+   *
+   */
+
+  p = out;
+
+  p = strchr (p, '\n');
+  if (p) {
+    *p = '\0';
+    p++;
+  }
+  else {
+    reply_with_error ("truncated output");
+    return NULL;
+  }
+
+  /* If the path is the btrfs root, `btrfs subvolume show' reports:
+   *   <path> is btrfs root
+   */
+  if (strstr(out, "is btrfs root") != NULL) {
+    reply_with_error ("%s is btrfs root", subvolume);
+    return NULL;
+  }
+
+  /* The first line is the path of the subvolume. */
+  if (add_string (&ret, strdup("path")) == -1) {
+    return NULL;
+  }
+  if (add_string (&ret, out) == -1) {
+    return NULL;
+  }
+
+  /* Read the lines and split into "key: value". */
+  while (*p) {
+    /* leading spaces and tabs */
+    while (*p && c_isspace (*p)) p++;
+
+    pend = strchrnul (p, '\n');
+    if (*pend == '\n') {
+      *pend = '\0';
+      pend++;
+    }
+
+    if (!*p) continue;
+
+    colon = strchr (p, ':');
+    if (colon) {
+      *colon = '\0';
+
+      /* snapshot is special, see the output above */
+      if (strncmp(p, "Snapshot", sizeof("Snapshot") - 1) ==
0) {
+        char *ss = NULL;
+
+        if (add_string (&ret, p) == -1) {
+          return NULL;
+        }
+
+        /* each line is the path of a snapshot. */
+        p = pend;
+        while (*p && strchr(p, ':') == NULL) {
+          while (*p && c_isspace (*p)) p++;
+          pend = strchrnul (p, '\n');
+          if (*pend == '\n') {
+            *pend = '\0';
+            pend++;
+          }
+          if (ss) {
+            ss = realloc(ss, strlen(ss) + strlen(p));
+            strcat(ss, ",");
+            strcat(ss, p);
+          } else {
+            ss = strdup(p);
+          }
+
+          p = pend;
+        }
+
+        if (ss) {
+          if (add_string (&ret, ss) == -1) {
+            free(ss);
+            return NULL;
+          }
+        }
+        else {
+          if (add_string (&ret, strdup("")) == -1) {
+            return NULL;
+          }
+        }
+
+        continue;
+      }
+
+      do { colon++; } while (*colon && c_isspace (*colon));
+
+      if (add_string (&ret, p) == -1) {
+        return NULL;
+      }
+      if (add_string (&ret, colon) == -1) {
+        return NULL;
+      }
+    }
+    else {
+      if (add_string (&ret, p) == -1) {
+        return NULL;
+      }
+      if (add_string (&ret, "") == -1) {
+        return NULL;
+      }
+    }
+
+    p = pend;
+  }
+
+  if (end_stringsbuf (&ret) == -1)
+    return NULL;
+
+  return ret.argv;
+
+}
diff --git a/generator/actions.ml b/generator/actions.ml
index cf96039..24d3ecc 100644
--- a/generator/actions.ml
+++ b/generator/actions.ml
@@ -12014,6 +12014,15 @@ This is the internal call which implements
C<guestfs_lstatnslist>." };
     longdesc = "\
 Get the default subvolume or snapshot of a filesystem mounted at
C<mountpoint>." };
 
+  { defaults with
+    name = "btrfs_subvolume_show";
+    style = RHashtable "btrfssubvolumeinfo", [Pathname
"subvolume"], [];
+    proc_nr = Some 425;
+    optional = Some "btrfs"; camel_name =
"BTRFSSubvolumeShow";
+    shortdesc = "show detailed information of the subvolume";
+    longdesc = "\
+show detailed information of the subvolume." };
+
 ]
 
 (* Non-API meta-commands available only in guestfish.
diff --git a/src/MAX_PROC_NR b/src/MAX_PROC_NR
index 9524ef4..5e4a522 100644
--- a/src/MAX_PROC_NR
+++ b/src/MAX_PROC_NR
@@ -1 +1 @@
-424
+425
-- 
1.9.3

On Friday 21 November 2014 13:17:55 Hu Tao wrote:
> btrfs_subvolume_create creates only subvolumes. btrfs_subvolume_delete
> deletes subvolumes or snapshots.
> 
> Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
> ---
>  generator/actions.ml | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/generator/actions.ml b/generator/actions.ml
> index 89332f5..fe492e6 100644
> --- a/generator/actions.ml
> +++ b/generator/actions.ml
> @@ -10248,19 +10248,19 @@ of the snapshot, in the form
> C</path/to/dest/name>." }; ["btrfs_subvolume_create";
"/test1"];
>           ["btrfs_subvolume_delete"; "/test1"]]), []
>      ];
> -    shortdesc = "delete a btrfs snapshot";
> +    shortdesc = "delete a btrfs subvolume or snapshot";
>      longdesc = "\
> -Delete the named btrfs subvolume." };
> +Delete the named btrfs subvolume or snapshot." };
> 
>    { defaults with
>      name = "btrfs_subvolume_create";
>      style = RErr, [Pathname "dest"], [];
>      proc_nr = Some 324;
>      optional = Some "btrfs"; camel_name =
"BTRFSSubvolumeCreate";
> -    shortdesc = "create a btrfs snapshot";
> +    shortdesc = "create a btrfs subvolume";
>      longdesc = "\
>  Create a btrfs subvolume.  The C<dest> argument is the destination
> -directory and the name of the snapshot, in the form
> C</path/to/dest/name>." }; +directory and the name of the
subvolume,
> in the form C</path/to/dest/name>." };
> 
>    { defaults with
>      name = "btrfs_subvolume_list";
LGTM.

-- 
Pino Toscano

On Friday 21 November 2014 13:17:56 Hu Tao wrote:
> Parameter `ro' is for creating readonly btrfs snapshot.
> 
> Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
> ---
>  daemon/btrfs.c       | 11 ++++++++++-
>  generator/actions.ml |  4 ++--
>  2 files changed, 12 insertions(+), 3 deletions(-)
> 
> diff --git a/daemon/btrfs.c b/daemon/btrfs.c
> index 7a4d43d..b630bce 100644
> --- a/daemon/btrfs.c
> +++ b/daemon/btrfs.c
> @@ -208,7 +208,7 @@ do_mkfs_btrfs (char *const *devices,
>  }
> 
>  int
> -do_btrfs_subvolume_snapshot (const char *source, const char *dest)
> +do_btrfs_subvolume_snapshot (const char *source, const char *dest,
> int ro) {
>    const size_t MAX_ARGS = 64;
>    const char *argv[MAX_ARGS];
> @@ -231,6 +231,15 @@ do_btrfs_subvolume_snapshot (const char *source,
> const char *dest) ADD_ARG (argv, i, str_btrfs);
>    ADD_ARG (argv, i, "subvolume");
>    ADD_ARG (argv, i, "snapshot");
> +
> +  /* Optional arguments. */
> +  if (!(optargs_bitmask &
> GUESTFS_BTRFS_SUBVOLUME_SNAPSHOT_RO_BITMASK)) +    ro = 0;
> +
> +  if (ro) {
> +    ADD_ARG (argv, i, "-r");
> +  }
> +
I would make this bit simplier:

 if ((optargs_bitmask & GUESTFS_BTRFS_SUBVOLUME_SNAPSHOT_RO_BITMASK)
     && ro)
   ADD_ARG (argv, i, "-r");

Also, seen in the other patches as well, you don't need { ... } brackets 
for blocks of just one instructions.

> diff --git a/generator/actions.ml b/generator/actions.ml
> index fe492e6..850e58d 100644
> --- a/generator/actions.ml
> +++ b/generator/actions.ml
> @@ -10217,7 +10217,7 @@ See C<guestfs_get_e2generation>." };
> 
>    { defaults with
>      name = "btrfs_subvolume_snapshot";
> -    style = RErr, [Pathname "source"; Pathname
"dest"], [];
> +    style = RErr, [Pathname "source"; Pathname
"dest"], [OBool "ro"];
> proc_nr = Some 322;
>      optional = Some "btrfs"; camel_name =
"BTRFSSubvolumeSnapshot";
>      tests = [
You must set once_had_no_optargs = true for this action, as it currently 
has no optional arguments; see generator/README.

-- 
Pino Toscano

On Friday 21 November 2014 13:17:58 Hu Tao wrote:
> Parameter `qgroupid' is for adding the created subvolume to a qgroup.
> 
> Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
> ---
>  daemon/btrfs.c       | 10 +++++++++-
>  generator/actions.ml | 15 ++++++++-------
>  2 files changed, 17 insertions(+), 8 deletions(-)
> 
> diff --git a/daemon/btrfs.c b/daemon/btrfs.c
> index a20afca..0f525fa 100644
> --- a/daemon/btrfs.c
> +++ b/daemon/btrfs.c
> @@ -291,7 +291,7 @@ do_btrfs_subvolume_delete (const char *subvolume)
>  }
>  
>  int
> -do_btrfs_subvolume_create (const char *dest)
> +do_btrfs_subvolume_create (const char *dest, const char *qgroupid)
>  {
>    const size_t MAX_ARGS = 64;
>    const char *argv[MAX_ARGS];
> @@ -309,6 +309,14 @@ do_btrfs_subvolume_create (const char *dest)
>    ADD_ARG (argv, i, str_btrfs);
>    ADD_ARG (argv, i, "subvolume");
>    ADD_ARG (argv, i, "create");
> +
> +  /* Optional arguments. */
> +  if (optargs_bitmask &
GUESTFS_BTRFS_SUBVOLUME_CREATE_QGROUPID_BITMASK) {
> +    ADD_ARG (argv, i, "-i");
> +    ADD_ARG (argv, i, qgroupid);
> +  }
> +
> +
>    ADD_ARG (argv, i, dest_buf);
>    ADD_ARG (argv, i, NULL);
>  
> diff --git a/generator/actions.ml b/generator/actions.ml
> index 30b839c..1c1fcff 100644
> --- a/generator/actions.ml
> +++ b/generator/actions.ml
> @@ -10225,9 +10225,9 @@ See C<guestfs_get_e2generation>." };
>          [["mkfs_btrfs"; "/dev/sda1"; "";
""; "NOARG"; ""; "NOARG";
"NOARG"; ""; ""];
>           ["mount"; "/dev/sda1"; "/"];
>           ["mkdir"; "/dir"];
> -         ["btrfs_subvolume_create"; "/test1"];
> -         ["btrfs_subvolume_create"; "/test2"];
> -         ["btrfs_subvolume_create"; "/dir/test3"];
> +         ["btrfs_subvolume_create"; "/test1";
"NOARG"];
> +         ["btrfs_subvolume_create"; "/test2";
"NOARG"];
> +         ["btrfs_subvolume_create"; "/dir/test3";
"NOARG"];
>           ["btrfs_subvolume_snapshot"; "/dir/test3";
"/dir/test5"; "true"; "NOARG"];
>           ["btrfs_subvolume_snapshot"; "/dir/test3";
"/dir/test6"; ""; "0/1000"]]), []
>      ];
> @@ -10246,7 +10246,7 @@ of the snapshot, in the form
C</path/to/dest/name>." };
>        InitPartition, Always, TestRun (
>          [["mkfs_btrfs"; "/dev/sda1"; "";
""; "NOARG"; ""; "NOARG";
"NOARG"; ""; ""];
>           ["mount"; "/dev/sda1"; "/"];
> -         ["btrfs_subvolume_create"; "/test1"];
> +         ["btrfs_subvolume_create"; "/test1";
"NOARG"];
>           ["btrfs_subvolume_delete"; "/test1"]]), []
>      ];
>      shortdesc = "delete a btrfs subvolume or snapshot";
> @@ -10255,13 +10255,14 @@ Delete the named btrfs subvolume or
snapshot." };
>  
>    { defaults with
>      name = "btrfs_subvolume_create";
> -    style = RErr, [Pathname "dest"], [];
> +    style = RErr, [Pathname "dest"], [OString
"qgroupid"];
>      proc_nr = Some 324;
>      optional = Some "btrfs"; camel_name =
"BTRFSSubvolumeCreate";
>      shortdesc = "create a btrfs subvolume";
Like in patch 2, you need once_had_no_optargs = true for this as well.
>      longdesc = "\
>  Create a btrfs subvolume.  The C<dest> argument is the destination
> -directory and the name of the subvolume, in the form
C</path/to/dest/name>." };
> +directory and the name of the subvolume, in the form
C</path/to/dest/name>.
> +The C<qgroupid> adds the newly created subvolume to a qgroup."
};
"The optional C<qgroupid> parameter represents the qgroup which the
newly created subvolume should be added to."

or something like that, I'm not an English native speaker either...

-- 
Pino Toscano

On Friday 21 November 2014 13:17:56 Hu Tao wrote:
> diff --git a/generator/actions.ml b/generator/actions.ml
> index fe492e6..850e58d 100644
> --- a/generator/actions.ml
> +++ b/generator/actions.ml
> @@ -10217,7 +10217,7 @@ See C<guestfs_get_e2generation>." };
> 
>    { defaults with
>      name = "btrfs_subvolume_snapshot";
> -    style = RErr, [Pathname "source"; Pathname
"dest"], [];
> +    style = RErr, [Pathname "source"; Pathname
"dest"], [OBool "ro"];
>      proc_nr = Some 322;
>      optional = Some "btrfs"; camel_name =
"BTRFSSubvolumeSnapshot";
>      tests = [
> @@ -10228,7 +10228,7 @@ See C<guestfs_get_e2generation>." };
>           ["btrfs_subvolume_create"; "/test1"];
>           ["btrfs_subvolume_create"; "/test2"];
>           ["btrfs_subvolume_create"; "/dir/test3"];
> -         ["btrfs_subvolume_snapshot"; "/dir/test3";
"/dir/test4"]]), []
> +         ["btrfs_subvolume_snapshot"; "/dir/test3";
"/dir/test5"; "true"]]), [] ];
>      shortdesc = "create a writable btrfs snapshot";
>      longdesc = "\
Ah, forgot to add: can you please document the new "ro" optarg in the
longdesc?

-- 
Pino Toscano

On Friday 21 November 2014 13:17:57 Hu Tao wrote:
> Parameter `qgroupid' is for adding the created snapshot to a qgroup.
> 
> Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
> ---
>  daemon/btrfs.c       | 8 +++++++-
>  generator/actions.ml | 5 +++--
>  2 files changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/daemon/btrfs.c b/daemon/btrfs.c
> index b630bce..a20afca 100644
> --- a/daemon/btrfs.c
> +++ b/daemon/btrfs.c
> @@ -208,7 +208,8 @@ do_mkfs_btrfs (char *const *devices,
>  }
>  
>  int
> -do_btrfs_subvolume_snapshot (const char *source, const char *dest, int ro)
> +do_btrfs_subvolume_snapshot (const char *source, const char *dest, int ro,
> +                             const char *qgroupid)
>  {
>    const size_t MAX_ARGS = 64;
>    const char *argv[MAX_ARGS];
> @@ -240,6 +241,11 @@ do_btrfs_subvolume_snapshot (const char *source, const
char *dest, int ro)
>      ADD_ARG (argv, i, "-r");
>    }
>  
> +  if (optargs_bitmask &
GUESTFS_BTRFS_SUBVOLUME_SNAPSHOT_QGROUPID_BITMASK) {
> +    ADD_ARG (argv, i, "-i");
> +    ADD_ARG (argv, i, qgroupid);
> +  }
> +
>    ADD_ARG (argv, i, source_buf);
>    ADD_ARG (argv, i, dest_buf);
>    ADD_ARG (argv, i, NULL);
> diff --git a/generator/actions.ml b/generator/actions.ml
> index 850e58d..30b839c 100644
> --- a/generator/actions.ml
> +++ b/generator/actions.ml
> @@ -10217,7 +10217,7 @@ See C<guestfs_get_e2generation>." };
>  
>    { defaults with
>      name = "btrfs_subvolume_snapshot";
> -    style = RErr, [Pathname "source"; Pathname
"dest"], [OBool "ro"];
> +    style = RErr, [Pathname "source"; Pathname
"dest"], [OBool "ro"; OString "qgroupid"];
>      proc_nr = Some 322;
>      optional = Some "btrfs"; camel_name =
"BTRFSSubvolumeSnapshot";
>      tests = [
> @@ -10228,7 +10228,8 @@ See C<guestfs_get_e2generation>." };
>           ["btrfs_subvolume_create"; "/test1"];
>           ["btrfs_subvolume_create"; "/test2"];
>           ["btrfs_subvolume_create"; "/dir/test3"];
> -         ["btrfs_subvolume_snapshot"; "/dir/test3";
"/dir/test5"; "true"]]), []
> +         ["btrfs_subvolume_snapshot"; "/dir/test3";
"/dir/test5"; "true"; "NOARG"];
> +         ["btrfs_subvolume_snapshot"; "/dir/test3";
"/dir/test6"; ""; "0/1000"]]), []
>      ];
>      shortdesc = "create a writable btrfs snapshot";
>      longdesc = "\
This needs the documentation for the "qgroupid" optarg in the
longdesc.
LGTM otherwise.

-- 
Pino Toscano

On Friday 21 November 2014 13:17:59 Hu Tao wrote:
> btrfs_subvolume_get_default is for getting the default subvolume of
> a btrfs filesystem.
> 
> Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
> ---
>  daemon/btrfs.c       | 38 ++++++++++++++++++++++++++++++++++++++
>  generator/actions.ml |  9 +++++++++
>  src/MAX_PROC_NR      |  2 +-
>  3 files changed, 48 insertions(+), 1 deletion(-)
> 
> diff --git a/daemon/btrfs.c b/daemon/btrfs.c
> index 0f525fa..e179b57 100644
> --- a/daemon/btrfs.c
> +++ b/daemon/btrfs.c
> @@ -549,6 +549,44 @@ do_btrfs_subvolume_set_default (int64_t id, const 
char *fs)
>  }
>  
>  int
> +do_btrfs_subvolume_get_default (const char *fs)
> +{
> +  const size_t MAX_ARGS = 64;
> +  const char *argv[MAX_ARGS];
> +  size_t i = 0;
> +  CLEANUP_FREE char *fs_buf = NULL;
> +  CLEANUP_FREE char *err = NULL;
> +  CLEANUP_FREE char *out = NULL;
> +  int r;
> +
> +  fs_buf = sysroot_path (fs);
> +  if (fs_buf == NULL) {
> +    reply_with_perror ("malloc");
> +    return -1;
> +  }
> +
> +  ADD_ARG (argv, i, str_btrfs);
> +  ADD_ARG (argv, i, "subvolume");
> +  ADD_ARG (argv, i, "get-default");
> +  ADD_ARG (argv, i, fs_buf);
> +  ADD_ARG (argv, i, NULL);
> +
> +  r = commandv (&out, &err, argv);
> +  fprintf(stderr, "%s\n", out);
This looks like a leftover? Otherwise, print it only when "debug" is
enabled (if (debug) ...).
> +  if (r == -1) {
> +    reply_with_error ("%s: %s", fs, err);
> +    return -1;
> +  }
> +  r = -1;
Most probably it is not needed to manually reset r.
> +  if (sscanf (out, "ID %" SCNi32, &r) != 1) {
It would be simplier to just use xstrtol to parse the output.
> +    reply_with_error ("%s: expected output, but got nothing", 
argv[0]);

More than "nothing", "not a number". I'd also append the
whole output
here.
> diff --git a/generator/actions.ml b/generator/actions.ml
> index 1c1fcff..cf96039 100644
> --- a/generator/actions.ml
> +++ b/generator/actions.ml
> @@ -12005,6 +12005,15 @@ This is the same as the C<lstat(2)> system 
call." };
>      longdesc = "\
>  This is the internal call which implements
C<guestfs_lstatnslist>."
};
>  
> +  { defaults with
> +    name = "btrfs_subvolume_get_default";
> +    style = RInt "id", [Pathname "mountpoint"], [];
> +    proc_nr = Some 424;
> +    optional = Some "btrfs"; camel_name =
"BTRFSSubvolumeGetDefault";
> +    shortdesc = "get the default subvolume or snapshot of a 
filesystem";
> +    longdesc = "\
> +Get the default subvolume or snapshot of a filesystem mounted at 
C<mountpoint>." };
> +
>  ]
>  
>  (* Non-API meta-commands available only in guestfish.
> diff --git a/src/MAX_PROC_NR b/src/MAX_PROC_NR
> index 5721413..9524ef4 100644
> --- a/src/MAX_PROC_NR
> +++ b/src/MAX_PROC_NR
> @@ -1 +1 @@
> -423
> +424
> -- 
> 1.9.3
> 
-- 
Pino Toscano

On Friday 21 November 2014 13:18:00 Hu Tao wrote:
> btrfs_subvolume_show shows the detailed information of a subvolume or
> snapshot.
> 
> Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
> ---
>  daemon/btrfs.c       | 167
+++++++++++++++++++++++++++++++++++++++++++++++++++
>  generator/actions.ml |   9 +++
>  src/MAX_PROC_NR      |   2 +-
>  3 files changed, 177 insertions(+), 1 deletion(-)
> 
> diff --git a/daemon/btrfs.c b/daemon/btrfs.c
> index e179b57..36ba588 100644
> --- a/daemon/btrfs.c
> +++ b/daemon/btrfs.c
> @@ -29,6 +29,7 @@
>  #include "actions.h"
>  #include "optgroups.h"
>  #include "xstrtol.h"
> +#include "c-ctype.h"
>  
>  GUESTFSD_EXT_CMD(str_btrfs, btrfs);
>  GUESTFSD_EXT_CMD(str_btrfstune, btrfstune);
> @@ -813,3 +814,169 @@ do_btrfs_fsck (const char *device, int64_t
superblock, int repair)
>  
>    return 0;
>  }
> +
> +char **do_btrfs_subvolume_show (const char *subvolume)
> +{
> +  const size_t MAX_ARGS = 64;
> +  const char *argv[MAX_ARGS];
> +  size_t i = 0;
> +  CLEANUP_FREE char *subvolume_buf = NULL;
> +  CLEANUP_FREE char *err = NULL;
> +  CLEANUP_FREE char *out = NULL;
> +  char *p, *pend, *colon;
> +  DECLARE_STRINGSBUF (ret);
> +  int r;
> +
> +  subvolume_buf = sysroot_path (subvolume);
> +  if (subvolume_buf == NULL) {
> +    reply_with_perror ("malloc");
> +    return NULL;
> +  }
> +
> +  ADD_ARG (argv, i, str_btrfs);
> +  ADD_ARG (argv, i, "subvolume");
> +  ADD_ARG (argv, i, "show");
> +  ADD_ARG (argv, i, subvolume_buf);
> +  ADD_ARG (argv, i, NULL);
> +
> +  r = commandv (&out, &err, argv);
> +  if (r == -1) {
> +    reply_with_error ("%s: %s", subvolume, err);
> +    return NULL;
> +  }
> +
> +  /* Output is:
> +   *
> +   * /
> +   *         Name:                   root
> +   *         uuid:                   c875169e-cf4e-a04d-9959-b667dec36234
> +   *         Parent uuid:            -
> +   *         Creation time:          2014-11-13 10:13:08
> +   *         Object ID:              256
> +   *         Generation (Gen):       6579
> +   *         Gen at creation:        5
> +   *         Parent:                 5
> +   *         Top Level:              5
> +   *         Flags:                  -
> +   *         Snapshot(s):
> +   *                                 snapshots/test1
> +   *                                 snapshots/test2
> +   *                                 snapshots/test3
> +   *
> +   */
> +
> +  p = out;
> +
> +  p = strchr (p, '\n');
> +  if (p) {
> +    *p = '\0';
> +    p++;
> +  }
> +  else {
Minor style note:
  } else {

(also in other parts of this patch)
> +    reply_with_error ("truncated output");
I'd print out anyway, to ease debugging failures a bit.
> +    return NULL;
> +  }
> +
> +  /* If the path is the btrfs root, `btrfs subvolume show' reports:
> +   *   <path> is btrfs root
> +   */
> +  if (strstr(out, "is btrfs root") != NULL) {
Take care of adding a space before parenthesis (also in other parts of
this patch).
> +    reply_with_error ("%s is btrfs root", subvolume);
> +    return NULL;
> +  }
> +
> +  /* The first line is the path of the subvolume. */
> +  if (add_string (&ret, strdup("path")) == -1) {
add_string duplicates the string, so you don't need to do that
manually.
> +    return NULL;
> +  }
> +  if (add_string (&ret, out) == -1) {
> +    return NULL;
> +  }
> +
> +  /* Read the lines and split into "key: value". */
> +  while (*p) {
> +    /* leading spaces and tabs */
> +    while (*p && c_isspace (*p)) p++;
Properly indent such lines, so:
  while (*p && c_isspace (*p))
    p++;

(also, a minor optimization is to use ++p instead of p++, as it can
avoid a temporary value)
> +
> +    pend = strchrnul (p, '\n');
> +    if (*pend == '\n') {
> +      *pend = '\0';
> +      pend++;
> +    }
> +
> +    if (!*p) continue;
> +
> +    colon = strchr (p, ':');
> +    if (colon) {
> +      *colon = '\0';
> +
> +      /* snapshot is special, see the output above */
> +      if (strncmp(p, "Snapshot", sizeof("Snapshot") -
1) == 0) {
Please use the STR* macros we have in src/guestfs-internal-all.h.

Also, most probably it is better to match "Snapshot(s)", so if in the
future a new field starting with "Snapshot" is added then it won't
be
mistaken for this multiline one.
> +        char *ss = NULL;
> +
> +        if (add_string (&ret, p) == -1) {
> +          return NULL;
> +        }
Single statements don't need curly brackets (also in other parts of
the patch).
> +
> +        /* each line is the path of a snapshot. */
> +        p = pend;
> +        while (*p && strchr(p, ':') == NULL) {
This will break once the output will have fields after Snapshot, as
strchr(p, ':') will return a non-null value in one of the lines
following the first line after the Snapshot one.
> +          while (*p && c_isspace (*p)) p++;
> +          pend = strchrnul (p, '\n');
> +          if (*pend == '\n') {
> +            *pend = '\0';
> +            pend++;
> +          }
I see this code repeated already; I think it would be better to create
a small helper function like:
  char *analyze_line (char *p, char **field, char **value)
which would
- destructively update p (setting null bytes, just like it is done now)
- return in field the start of the field text
- return in value, if present, the start of the value (after the colon)
- return the pointer to the first character of the new line (or null,
  if none following)
this way it is IMHO easier to iterate over the lines, and also to detect
whether a line contains a field+value or just text.
> +          if (ss) {
> +            ss = realloc(ss, strlen(ss) + strlen(p));
If realloc fails, the return value is null; this means that the
following will leak ss in that case.

Also, sounds like you are missing "," in the length of the string?
> +            strcat(ss, ",");
Just save the length of ss before the realloc, and you can simply do
  ss[old_length_of_ss] = ',';
> +            strcat(ss, p);
You can easily use memcpy here:
  memcpy (ss + old_length_of_ss + 1, p, strlen (p));
> +          } else {
> +            ss = strdup(p);
Missing check for failed strdup.
> +          }
> +
> +          p = pend;
> +        }
> +
> +        if (ss) {
> +          if (add_string (&ret, ss) == -1) {
This needs to be add_string_nodup.
> +            free(ss);
No need to free ss here; theoretically add_string will take care of it,
be it added to the stringbuf or freed on error.
> +            return NULL;
> +          }
> +        }
> +        else {
> +          if (add_string (&ret, strdup("")) == -1) {
> +            return NULL;
> +          }
> +        }
If there are no elements for "Snapshot(s)", then it would be better
to just not add an empty hash element.
> +
> +        continue;
> +      }
> +
> +      do { colon++; } while (*colon && c_isspace (*colon));
> +      if (add_string (&ret, p) == -1) {
> +        return NULL;
> +      }
> +      if (add_string (&ret, colon) == -1) {
> +        return NULL;
> +      }
At least from the example output added as comment, it seems that
"not available" values might be "-" -- it'd just not add
those, since
as users of this API would still need to check for the existency of
a certain key in the returned hash.
> +    }
> +    else {
> +      if (add_string (&ret, p) == -1) {
> +        return NULL;
> +      }
> +      if (add_string (&ret, "") == -1) {
> +        return NULL;
> +      }
As above, I would not add elements with empty values in the hash.
> +    }
> +
> +    p = pend;
> +  }
> +
> +  if (end_stringsbuf (&ret) == -1)
> +    return NULL;
> +
> +  return ret.argv;
> +
> +}
> diff --git a/generator/actions.ml b/generator/actions.ml
> index cf96039..24d3ecc 100644
> --- a/generator/actions.ml
> +++ b/generator/actions.ml
> @@ -12014,6 +12014,15 @@ This is the internal call which implements
C<guestfs_lstatnslist>." };
>      longdesc = "\
>  Get the default subvolume or snapshot of a filesystem mounted at
C<mountpoint>." };
>  
> +  { defaults with
> +    name = "btrfs_subvolume_show";
> +    style = RHashtable "btrfssubvolumeinfo", [Pathname
"subvolume"], [];
> +    proc_nr = Some 425;
> +    optional = Some "btrfs"; camel_name =
"BTRFSSubvolumeShow";
> +    shortdesc = "show detailed information of the subvolume";
"returns detailed information about the subvolume"
> +    longdesc = "\
> +show detailed information of the subvolume." };
Like above, making sure it is properly capitalized at the beginning.

-- 
Pino Toscano