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Maxim Perevedentsev

2015-Oct-22 17:05 UTC

[Libguestfs] [PATCH] Added btrfs support for vfs_min_size.

---
 daemon/btrfs.c       | 69 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 daemon/daemon.h      |  1 +
 daemon/fs-min-size.c | 50 ++++++++++++++++++++++++++++++++++++-
 generator/actions.ml |  6 ++++-
 4 files changed, 124 insertions(+), 2 deletions(-)

diff --git a/daemon/btrfs.c b/daemon/btrfs.c
index ddb029d..d2d85f3 100644
--- a/daemon/btrfs.c
+++ b/daemon/btrfs.c
@@ -2190,3 +2190,72 @@ do_btrfs_replace (const char *srcdev, const char
*targetdev,

   return 0;
 }
+
+/* btrfs command add a new command
+ * inspect-internal min-dev-size <path>
+ * since v4.2
+ * We could check whether 'btrfs' supports
+ * 'min-dev-size' command by checking the output of
+ * 'btrfs --help' command.
+ */
+static int
+test_btrfs_min_dev_size (void)
+{
+  CLEANUP_FREE char *err = NULL, *out = NULL;
+  static int result = -1;
+  if (result != -1)
+    return result;
+
+  const char *cmd_pattern = "btrfs inspect-internal min-dev-size";
+
+  int r = commandr (&out, &err, str_btrfs, "--help", NULL);
+
+  if (r == -1) {
+    reply_with_error ("btrfs: %s", err);
+    return -1;
+  }
+
+  if (strstr (out, cmd_pattern) == NULL)
+    result = 0;
+  else
+    result = 1;
+
+  return result;
+}
+
+int64_t
+btrfs_minimum_size (const char *path)
+{
+  CLEANUP_FREE char *err = NULL, *out = NULL;
+  int64_t ret = 0;
+  int min_size_supported = test_btrfs_min_dev_size ();
+  if (min_size_supported == -1)
+    return -1;
+  else if (min_size_supported == 0)
+    NOT_SUPPORTED (-1, "'btrfs inspect-internal min-dev-size' \
+                        needs btrfs-progs >= 4.2");
+
+  int r = command (&out, &err, str_btrfs, "inspect-internal",
+                   "min-dev-size", path, NULL);
+
+  if (r == -1) {
+    reply_with_error ("%s", err);
+    return -1;
+  }
+
+#if __WORDSIZE == 64
+#define XSTRTOD64 xstrtol
+#else
+#define XSTRTOD64 xstrtoll
+#endif
+
+  if (XSTRTOD64 (out, NULL, 10, &ret, NULL) != LONGINT_OK) {
+    reply_with_error ("cannot parse minimum size");
+    return -1;
+  }
+
+#undef XSTRTOD64
+
+  return ret;
+}
+
diff --git a/daemon/daemon.h b/daemon/daemon.h
index 8bcc9bd..4a969dd 100644
--- a/daemon/daemon.h
+++ b/daemon/daemon.h
@@ -280,6 +280,7 @@ extern char *btrfs_get_label (const char *device);
 extern int btrfs_set_label (const char *device, const char *label);
 extern int btrfs_set_uuid (const char *device, const char *uuid);
 extern int btrfs_set_uuid_random (const char *device);
+extern int64_t btrfs_minimum_size (const char *path);

 /*-- in ntfs.c --*/
 extern char *ntfs_get_label (const char *device);
diff --git a/daemon/fs-min-size.c b/daemon/fs-min-size.c
index 4f93f8c..cb67b6f 100644
--- a/daemon/fs-min-size.c
+++ b/daemon/fs-min-size.c
@@ -21,16 +21,57 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
+#include <mntent.h>
+#include <sys/stat.h>
+#include <sys/types.h>

 #include "daemon.h"
 #include "actions.h"

+static char*
+get_mount_point (const char *device)
+{
+  FILE *fp;
+  struct mntent *m;
+  struct stat stat1, stat2;
+  char *path;
+
+  if (stat (device, &stat1) == -1) {
+    reply_with_perror ("stat: %s", device);
+    return NULL;
+  }
+
+  /* NB: Eventually we should aim to parse /proc/self/mountinfo, but
+   * that requires custom parsing code.
+   */
+  fp = setmntent ("/proc/mounts", "r");
+  if (fp == NULL) {
+    fprintf (stderr, "setmntent: %s: %m\n",
"/proc/mounts");
+    exit (EXIT_FAILURE);
+  }
+
+  while ((m = getmntent (fp)) != NULL) {
+      if (stat (m->mnt_fsname, &stat2) == 0) {
+        if (stat1.st_rdev == stat2.st_rdev) {
+          /* found it */
+		   path = strdup (m->mnt_dir);
+          endmntent (fp);
+          return path;
+        }
+      }
+  }
+
+  endmntent (fp);
+  reply_with_error ("device not mounted: %s", device);
+  return NULL;
+}
+
 int64_t
 do_vfs_minimum_size (const mountable_t *mountable)
 {
   int64_t r;

-  /* How we set the label depends on the filesystem type. */
+  /* How we get minimum size depends on the filesystem type. */
   CLEANUP_FREE char *vfs_type = do_vfs_type (mountable);
   if (vfs_type == NULL)
     return -1;
@@ -41,6 +82,13 @@ do_vfs_minimum_size (const mountable_t *mountable)
   else if (STREQ (vfs_type, "ntfs"))
     r = ntfs_minimum_size (mountable->device);

+  else if (STREQ (vfs_type, "btrfs")) {
+    CLEANUP_FREE char *path = get_mount_point (mountable->device);
+    if (path == NULL)
+      return -1;
+    r = btrfs_minimum_size (path);
+  }
+
   else
     NOT_SUPPORTED (-1, "don't know how to get minimum size of
'%s' filesystems",
                    vfs_type);
diff --git a/generator/actions.ml b/generator/actions.ml
index 62176ab..8832410 100644
--- a/generator/actions.ml
+++ b/generator/actions.ml
@@ -12761,6 +12761,10 @@ To read the UUID on a filesystem, call
C<guestfs_vfs_uuid>." };
       InitPartition, IfAvailable "ntfsprogs", TestRun(
         [["mkfs"; "ntfs"; "/dev/sda1";
""; "NOARG"; ""; ""; "NOARG"];
          ["vfs_minimum_size"; "/dev/sda1"]]), [];
+      InitPartition, Always, TestRun (
+        [["mkfs"; "btrfs"; "/dev/sda1";
""; "NOARG"; ""; ""; "NOARG"];
+         ["mount"; "/dev/sda1"; "/"];
+         ["vfs_minimum_size"; "/dev/sda1"]]), [];
     ];
     shortdesc = "get minimum filesystem size";
     longdesc = "\
@@ -12770,7 +12774,7 @@ This is the minimum possible size for filesystem
shrinking.
 If getting minimum size of specified filesystem is not supported,
 this will fail and set errno as ENOTSUP.

-See also L<ntfsresize(8)>, L<resize2fs(8)>." };
+See also L<ntfsresize(8)>, L<resize2fs(8)>,
L<btrfs(8)>." };

 ]

--
1.8.3.1

Richard W.M. Jones

2015-Oct-23 09:13 UTC

head link

Re: [Libguestfs] [PATCH] Added btrfs support for vfs_min_size.

On Thu, Oct 22, 2015 at 08:05:37PM +0300, Maxim Perevedentsev
wrote:> +/* btrfs command add a new command
> + * inspect-internal min-dev-size <path>
> + * since v4.2
> + * We could check whether 'btrfs' supports
> + * 'min-dev-size' command by checking the output of
> + * 'btrfs --help' command.
> + */
> +static int
> +test_btrfs_min_dev_size (void)
> +{
> +  CLEANUP_FREE char *err = NULL, *out = NULL;
> +  static int result = -1;
> +  if (result != -1)
> +    return result;
> +
> +  const char *cmd_pattern = "btrfs inspect-internal
min-dev-size";
> +
> +  int r = commandr (&out, &err, str_btrfs, "--help",
NULL);
Let's move variable decls to the top of the function, and add
a newline between variable decls and the rest of the code.
> +  if (r == -1) {
> +    reply_with_error ("btrfs: %s", err);
> +    return -1;
> +  }
> +
> +  if (strstr (out, cmd_pattern) == NULL)
> +    result = 0;
> +  else
> +    result = 1;
> +
> +  return result;
> +}
>
> +int64_t
> +btrfs_minimum_size (const char *path)
> +{
> +  CLEANUP_FREE char *err = NULL, *out = NULL;
> +  int64_t ret = 0;
> +  int min_size_supported = test_btrfs_min_dev_size ();
> +  if (min_size_supported == -1)
> +    return -1;
> +  else if (min_size_supported == 0)
> +    NOT_SUPPORTED (-1, "'btrfs inspect-internal min-dev-size'
\
> +                        needs btrfs-progs >= 4.2");
> +
> +  int r = command (&out, &err, str_btrfs,
"inspect-internal",
> +                   "min-dev-size", path, NULL);
Same here.
> +  if (r == -1) {
> +    reply_with_error ("%s", err);
> +    return -1;
> +  }
> +
> +#if __WORDSIZE == 64
> +#define XSTRTOD64 xstrtol
> +#else
> +#define XSTRTOD64 xstrtoll
> +#endif
> +
> +  if (XSTRTOD64 (out, NULL, 10, &ret, NULL) != LONGINT_OK) {
> +    reply_with_error ("cannot parse minimum size");
> +    return -1;
> +  }
> +
> +#undef XSTRTOD64
> +
> +  return ret;
> +}
> +
> diff --git a/daemon/daemon.h b/daemon/daemon.h
> index 8bcc9bd..4a969dd 100644
> --- a/daemon/daemon.h
> +++ b/daemon/daemon.h
> @@ -280,6 +280,7 @@ extern char *btrfs_get_label (const char *device);
>  extern int btrfs_set_label (const char *device, const char *label);
>  extern int btrfs_set_uuid (const char *device, const char *uuid);
>  extern int btrfs_set_uuid_random (const char *device);
> +extern int64_t btrfs_minimum_size (const char *path);
> 
>  /*-- in ntfs.c --*/
>  extern char *ntfs_get_label (const char *device);
> diff --git a/daemon/fs-min-size.c b/daemon/fs-min-size.c
> index 4f93f8c..cb67b6f 100644
> --- a/daemon/fs-min-size.c
> +++ b/daemon/fs-min-size.c
> @@ -21,16 +21,57 @@
>  #include <stdio.h>
>  #include <stdlib.h>
>  #include <unistd.h>
> +#include <mntent.h>
> +#include <sys/stat.h>
> +#include <sys/types.h>
> 
>  #include "daemon.h"
>  #include "actions.h"
> 
> +static char*
> +get_mount_point (const char *device)
> +{
This function now exists in daemon/mount.c and here.  It should
be shared.  Just make the function in daemon/mount.c non-static,
and declare it in daemon/guestfsd.h, and you don't need the copy.
> +  FILE *fp;
> +  struct mntent *m;
> +  struct stat stat1, stat2;
> +  char *path;
> +
> +  if (stat (device, &stat1) == -1) {
> +    reply_with_perror ("stat: %s", device);
> +    return NULL;
> +  }
> +
> +  /* NB: Eventually we should aim to parse /proc/self/mountinfo, but
> +   * that requires custom parsing code.
> +   */
> +  fp = setmntent ("/proc/mounts", "r");
> +  if (fp == NULL) {
> +    fprintf (stderr, "setmntent: %s: %m\n",
"/proc/mounts");
> +    exit (EXIT_FAILURE);
> +  }
> +
> +  while ((m = getmntent (fp)) != NULL) {
> +      if (stat (m->mnt_fsname, &stat2) == 0) {
> +        if (stat1.st_rdev == stat2.st_rdev) {
> +          /* found it */
> +		   path = strdup (m->mnt_dir);
> +          endmntent (fp);
> +          return path;
> +        }
> +      }
> +  }
> +
> +  endmntent (fp);
> +  reply_with_error ("device not mounted: %s", device);
> +  return NULL;
> +}
> +
>  int64_t
>  do_vfs_minimum_size (const mountable_t *mountable)
>  {
>    int64_t r;
> 
> -  /* How we set the label depends on the filesystem type. */
> +  /* How we get minimum size depends on the filesystem type. */
>    CLEANUP_FREE char *vfs_type = do_vfs_type (mountable);
>    if (vfs_type == NULL)
>      return -1;
> @@ -41,6 +82,13 @@ do_vfs_minimum_size (const mountable_t *mountable)
>    else if (STREQ (vfs_type, "ntfs"))
>      r = ntfs_minimum_size (mountable->device);
> 
> +  else if (STREQ (vfs_type, "btrfs")) {
> +    CLEANUP_FREE char *path = get_mount_point (mountable->device);
> +    if (path == NULL)
> +      return -1;
> +    r = btrfs_minimum_size (path);
> +  }
> +
>    else
>      NOT_SUPPORTED (-1, "don't know how to get minimum size of
'%s' filesystems",
>                     vfs_type);
> diff --git a/generator/actions.ml b/generator/actions.ml
> index 62176ab..8832410 100644
> --- a/generator/actions.ml
> +++ b/generator/actions.ml
> @@ -12761,6 +12761,10 @@ To read the UUID on a filesystem, call
C<guestfs_vfs_uuid>." };
>        InitPartition, IfAvailable "ntfsprogs", TestRun(
>          [["mkfs"; "ntfs"; "/dev/sda1";
""; "NOARG"; ""; ""; "NOARG"];
>           ["vfs_minimum_size"; "/dev/sda1"]]), [];
> +      InitPartition, Always, TestRun (
> +        [["mkfs"; "btrfs"; "/dev/sda1";
""; "NOARG"; ""; ""; "NOARG"];
> +         ["mount"; "/dev/sda1"; "/"];
> +         ["vfs_minimum_size"; "/dev/sda1"]]), [];
>      ];
>      shortdesc = "get minimum filesystem size";
>      longdesc = "\
> @@ -12770,7 +12774,7 @@ This is the minimum possible size for filesystem
shrinking.
>  If getting minimum size of specified filesystem is not supported,
>  this will fail and set errno as ENOTSUP.
> 
> -See also L<ntfsresize(8)>, L<resize2fs(8)>." };
> +See also L<ntfsresize(8)>, L<resize2fs(8)>,
L<btrfs(8)>." };
> 
>  ]
> 
The rest looks fine to me.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-top is 'top' for virtual machines.  Tiny program with many
powerful monitoring features, net stats, disk stats, logging, etc.
http://people.redhat.com/~rjones/virt-top

Maxim Perevedentsev

2015-Oct-23 15:48 UTC

head link

Re: [Libguestfs] [PATCH] Added btrfs support for vfs_min_size.

On 23.10.2015 12:13, Richard W.M. Jones wrote:> On Thu, Oct 22, 2015 at 08:05:37PM +0300, Maxim Perevedentsev wrote:
>> +static char*
>> +get_mount_point (const char *device)
>> +{
> This function now exists in daemon/mount.c and here.  It should
> be shared.  Just make the function in daemon/mount.c non-static,
> and declare it in daemon/guestfsd.h, and you don't need the copy.There's a difference in this function and mount.c: is_device_mounted()

get_mount_point: return ANY of mount points for specific device.
is_device_mounted: return whether a device has a mountpoint under /sysroot

Even
is_device_mounted()
{
   return (get_mount_point() != NULL);
}
may not work in case of multiple mountpoints, some under /sysroot and 
others - not.
So it's not obvious how to merge(?) these functions.

Other way is to use do_mountpoints() and check the returned hash (but 
this will have malloc overhead).

-- 
С уважением, Максим Переведенцев
Your sincerely, Maxim Perevedentsev

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