Libguestfs - Feb 2020 - [common PATCH v4 0/1] options: add '--blocksize' option for C-based tools

From: Nikolay Ivanets <stenavin@gmail.com>

v4 fixes issues found during code review:
- whitespace-change-only hunks are removed
- options are alphabetically orderred now

v3 is just a spelling correction spotted by Eric Blake
https://www.redhat.com/archives/libguestfs/2020-February/msg00111.html

In v2 I've moved '--blocksize' parameter description into the
separate
file called blocksize-option.pod so we can include it everywhere we need
similar to key-option.pod.
https://www.redhat.com/archives/libguestfs/2020-February/msg00099.html

v1 was here:
https://www.redhat.com/archives/libguestfs/2020-February/msg00096.html

Nikolay Ivanets (1):
  options: add '--blocksize' option for C-based tools

 options/Makefile.am          |  3 ++-
 options/blocksize-option.pod | 11 ++++++++++
 options/options.c            | 13 +++++++++++-
 options/options.h            | 41 ++++++++++++++++++++++++++++--------
 4 files changed, 57 insertions(+), 11 deletions(-)
 create mode 100644 options/blocksize-option.pod

-- 
2.17.2

From: Nikolay Ivanets <stenavin@gmail.com>

This patch adds '--blocksize' command line option parsing and handling
for guestfish and other C-based tools which share the same code from
this sub-module.

'--blocksize' will be a common for almost all libguestfs-based tools and
thus parameter description will be repeated all the time.  Let's move
it into blocksize-option.pod and include everywhere we need.
---
 options/Makefile.am          |  3 ++-
 options/blocksize-option.pod | 11 ++++++++++
 options/options.c            | 13 +++++++++++-
 options/options.h            | 41 ++++++++++++++++++++++++++++--------
 4 files changed, 57 insertions(+), 11 deletions(-)
 create mode 100644 options/blocksize-option.pod

diff --git a/options/Makefile.am b/options/Makefile.am
index 28940f1..394f668 100644
--- a/options/Makefile.am
+++ b/options/Makefile.am
@@ -18,7 +18,8 @@
 include $(top_srcdir)/subdir-rules.mk
 
 EXTRA_DIST = \
-	key-option.pod
+	key-option.pod \
+	blocksize-option.pod
 
 # liboptions.la contains guestfish code which is used in other
 # C tools for options parsing and a few other things
diff --git a/options/blocksize-option.pod b/options/blocksize-option.pod
new file mode 100644
index 0000000..7b96ebf
--- /dev/null
+++ b/options/blocksize-option.pod
@@ -0,0 +1,11 @@
+=item B<--blocksize=512>
+
+=item B<--blocksize=4096>
+
+=item B<--blocksize>
+
+This parameter sets the sector size of the disk image.  It affects all
+explicitly added subsequent disks after this parameter.  Using
+I<--blocksize> with no argument switches the disk sector size to the
+default value which is usually 512 bytes.  See also
+L<guestfs(3)/guestfs_add_drive_opts>.
diff --git a/options/options.c b/options/options.c
index fe63da9..63221ea 100644
--- a/options/options.c
+++ b/options/options.c
@@ -49,7 +49,8 @@
  * Handle the guestfish I<-a> option on the command line.
  */
 void
-option_a (const char *arg, const char *format, struct drv **drvsp)
+option_a (const char *arg, const char *format, int blocksize,
+          struct drv **drvsp)
 {
   struct uri uri;
   struct drv *drv;
@@ -69,6 +70,7 @@ option_a (const char *arg, const char *format, struct drv
**drvsp)
     drv->type = drv_a;
     drv->a.filename = uri.path;
     drv->a.format = format;
+    drv->a.blocksize = blocksize;
 
     free (uri.protocol);
   }
@@ -82,6 +84,7 @@ option_a (const char *arg, const char *format, struct drv
**drvsp)
     drv->uri.password = uri.password;
     drv->uri.format = format;
     drv->uri.orig_uri = arg;
+    drv->uri.blocksize = blocksize;
   }
 
   drv->next = *drvsp;
@@ -137,6 +140,10 @@ add_drives_handle (guestfs_h *g, struct drv *drv, size_t
drive_index)
         ad_optargs.bitmask |= GUESTFS_ADD_DRIVE_OPTS_DISCARD_BITMASK;
         ad_optargs.discard = drv->a.discard;
       }
+      if (drv->a.blocksize) {
+        ad_optargs.bitmask |= GUESTFS_ADD_DRIVE_OPTS_BLOCKSIZE_BITMASK;
+        ad_optargs.blocksize = drv->a.blocksize;
+      }
 
       r = guestfs_add_drive_opts_argv (g, drv->a.filename, &ad_optargs);
       if (r == -1)
@@ -170,6 +177,10 @@ add_drives_handle (guestfs_h *g, struct drv *drv, size_t
drive_index)
         ad_optargs.bitmask |= GUESTFS_ADD_DRIVE_OPTS_SECRET_BITMASK;
         ad_optargs.secret = drv->uri.password;
       }
+      if (drv->uri.blocksize) {
+        ad_optargs.bitmask |= GUESTFS_ADD_DRIVE_OPTS_BLOCKSIZE_BITMASK;
+        ad_optargs.blocksize = drv->uri.blocksize;
+      }
 
       r = guestfs_add_drive_opts_argv (g, drv->uri.path, &ad_optargs);
       if (r == -1)
diff --git a/options/options.h b/options/options.h
index 9b78302..4716e6f 100644
--- a/options/options.h
+++ b/options/options.h
@@ -65,6 +65,7 @@ struct drv {
       const char *format;   /* format (NULL == autodetect) */
       const char *cachemode;/* cachemode (NULL == default) */
       const char *discard;  /* discard (NULL == disable) */
+      int blocksize;        /* blocksize (0 == default) */
     } a;
     struct {
       char *path;           /* disk path */
@@ -74,6 +75,7 @@ struct drv {
       char *password;       /* password - can be NULL */
       const char *format;   /* format (NULL == autodetect) */
       const char *orig_uri; /* original URI (for error messages etc.) */
+      int blocksize;        /* blocksize (0 == default) */
     } uri;
     struct {
       char *guest;          /* guest name */
@@ -156,7 +158,7 @@ extern struct key_store *key_store_import_key (struct
key_store *ks, const struc
 extern void free_key_store (struct key_store *ks);
 
 /* in options.c */
-extern void option_a (const char *arg, const char *format, struct drv **drvsp);
+extern void option_a (const char *arg, const char *format, int blocksize,
struct drv **drvsp);
 extern void option_d (const char *arg, struct drv **drvsp);
 extern char add_drives_handle (guestfs_h *g, struct drv *drv, size_t
drive_index);
 #define add_drives(drv) add_drives_handle (g, drv, 0)
@@ -164,16 +166,18 @@ extern void mount_mps (struct mp *mp);
 extern void free_drives (struct drv *drv);
 extern void free_mps (struct mp *mp);
 
-#define OPTION_a                                \
-  do {                                          \
-  option_a (optarg, format, &drvs);             \
-  format_consumed = true;                       \
+#define OPTION_a                                  \
+  do {                                            \
+    option_a (optarg, format, blocksize, &drvs);  \
+    format_consumed = true;                       \
+    blocksize_consumed = true;                    \
   } while (0)
 
-#define OPTION_A                                \
-  do {                                          \
-    option_a (optarg, format, &drvs2);          \
-    format_consumed = true;                     \
+#define OPTION_A                                  \
+  do {                                            \
+    option_a (optarg, format, blocksize, &drvs2); \
+    format_consumed = true;                       \
+    blocksize_consumed = true;                    \
   } while (0)
 
 #define OPTION_c                                \
@@ -194,6 +198,15 @@ extern void free_mps (struct mp *mp);
     format_consumed = false;                    \
   } while (0)
 
+#define OPTION_blocksize                                               \
+  do {                                                                 \
+    if (!optarg || STREQ (optarg, ""))                               
\
+      blocksize = 0;                                                   \
+    else if (sscanf (optarg, "%d", &blocksize) != 1)             
\
+      error (EXIT_FAILURE, 0, _("--blocksize option is not
numeric")); \
+    blocksize_consumed = false;                                        \
+  } while (0)
+
 #define OPTION_i                                \
   inspector = 1
 
@@ -267,4 +280,14 @@ extern void free_mps (struct mp *mp);
     }                                                                   \
   } while (0)
 
+#define CHECK_OPTION_blocksize_consumed                                 \
+  do {                                                                  \
+    if (!blocksize_consumed) {                                          \
+      fprintf (stderr,                                                  \
+               _("%s: --blocksize parameter must appear before -a
parameter\n"), \
+               getprogname ());                                         \
+      exit (EXIT_FAILURE);                                              \
+    }                                                                   \
+  } while (0)
+
 #endif /* OPTIONS_H */
-- 
2.17.2