From 8dce43a3ea7a529bc37cbe5607a8d52186cc8169 Mon Sep 17 00:00:00 2001

From: "Richard W.M. Jones" <rjones@redhat.com>

Date: Tue, 28 Jun 2022 18:27:58 +0100

Subject: [PATCH] copy: Store the preferred block size in the operations struct

This will be used in a subsequent commit.  At the moment the preferred

block size for all sources / destinations is simply calculated and

stored.

(cherry picked from commit e6c42f8b2d447bbcc659d6dd33be67335834b2e5)

---

 copy/file-ops.c |  4 +++-

 copy/main.c     | 29 +++++++++++++++++++++++------

 copy/nbd-ops.c  | 10 ++++++++++

 copy/nbdcopy.h  |  4 +++-

 copy/null-ops.c |  1 +

 copy/pipe-ops.c |  1 +

 6 files changed, 41 insertions(+), 8 deletions(-)

diff --git a/copy/file-ops.c b/copy/file-ops.c

index ab37875..34f08e5 100644

--- a/copy/file-ops.c

+++ b/copy/file-ops.c

@@ -241,13 +241,15 @@ seek_hole_supported (int fd)

 struct rw *

 file_create (const char *name, int fd,

-             off_t st_size, bool is_block, direction d)

+             off_t st_size, uint64_t preferred,

+             bool is_block, direction d)

 {

   struct rw_file *rwf = calloc (1, sizeof *rwf);

   if (rwf == NULL) { perror ("calloc"); exit (EXIT_FAILURE); }

   rwf->rw.ops = &file_ops;

   rwf->rw.name = name;

+  rwf->rw.preferred = preferred;

   rwf->fd = fd;

   rwf->is_block = is_block;

diff --git a/copy/main.c b/copy/main.c

index cc379e9..19ec384 100644

--- a/copy/main.c

+++ b/copy/main.c

@@ -512,10 +512,26 @@ open_local (const char *filename, direction d)

     fprintf (stderr, "%s: %s: %m\n", prog, filename);

     exit (EXIT_FAILURE);

   }

-  if (S_ISBLK (stat.st_mode) || S_ISREG (stat.st_mode))

-    return file_create (filename, fd, stat.st_size, S_ISBLK (stat.st_mode), d);

-  else {

-    /* Probably stdin/stdout, a pipe or a socket. */

+  if (S_ISREG (stat.st_mode))   /* Regular file. */

+    return file_create (filename, fd,

+                        stat.st_size, (uint64_t) stat.st_blksize, false, d);

+  else if (S_ISBLK (stat.st_mode)) { /* Block device. */

+    unsigned int blkioopt;

+

+#ifdef BLKIOOPT

+    if (ioctl (fd, BLKIOOPT, &blkioopt) == -1) {

+      fprintf (stderr, "warning: cannot get optimal I/O size: %s: %m",

+               filename);

+      blkioopt = 4096;

+    }

+#else

+    blkioopt = 4096;

+#endif

+

+    return file_create (filename, fd,

+                        stat.st_size, (uint64_t) blkioopt, true, d);

+  }

+  else {              /* Probably stdin/stdout, a pipe or a socket. */

     synchronous = true;        /* Force synchronous mode for pipes. */

     return pipe_create (filename, fd);

   }

@@ -528,8 +544,9 @@ print_rw (struct rw *rw, const char *prefix, FILE *fp)

   char buf[HUMAN_SIZE_LONGEST];

   fprintf (fp, "%s: %s \"%s\"\n", prefix, rw->ops->ops_name, rw->name);

-  fprintf (fp, "%s: size=%" PRIi64 " (%s)\n",

-           prefix, rw->size, human_size (buf, rw->size, NULL));

+  fprintf (fp, "%s: size=%" PRIi64 " (%s), preferred block size=%" PRIu64 "\n",

+           prefix, rw->size, human_size (buf, rw->size, NULL),

+           rw->preferred);

 }

 /* Default implementation of rw->ops->get_extents for backends which

diff --git a/copy/nbd-ops.c b/copy/nbd-ops.c

index 3bc26ba..0988634 100644

--- a/copy/nbd-ops.c

+++ b/copy/nbd-ops.c

@@ -112,12 +112,22 @@ open_one_nbd_handle (struct rw_nbd *rwn)

    * the same way.

    */

   if (rwn->handles.len == 0) {

+    int64_t block_size;

+

     rwn->can_zero = nbd_can_zero (nbd) > 0;

+

     rwn->rw.size = nbd_get_size (nbd);

     if (rwn->rw.size == -1) {

       fprintf (stderr, "%s: %s: %s\n", prog, rwn->rw.name, nbd_get_error ());

       exit (EXIT_FAILURE);

     }

+

+    block_size = nbd_get_block_size (nbd, LIBNBD_SIZE_PREFERRED);

+    if (block_size == -1) {

+      fprintf (stderr, "%s: %s: %s\n", prog, rwn->rw.name, nbd_get_error ());

+      exit (EXIT_FAILURE);

+    }

+    rwn->rw.preferred = block_size == 0 ? 4096 : block_size;

   }

   if (handles_append (&rwn->handles, nbd) == -1) {

diff --git a/copy/nbdcopy.h b/copy/nbdcopy.h

index 19797df..9438cce 100644

--- a/copy/nbdcopy.h

+++ b/copy/nbdcopy.h

@@ -43,6 +43,7 @@ struct rw {

   struct rw_ops *ops;           /* Operations. */

   const char *name;             /* Printable name, for error messages etc. */

   int64_t size;                 /* May be -1 for streams. */

+  uint64_t preferred;           /* Preferred block size. */

   /* Followed by private data for the particular subtype. */

 };

@@ -53,7 +54,8 @@ typedef enum { READING, WRITING } direction;

 /* Create subtypes. */

 extern struct rw *file_create (const char *name, int fd,

-                               off_t st_size, bool is_block, direction d);

+                               off_t st_size, uint64_t preferred,

+                               bool is_block, direction d);

 extern struct rw *nbd_rw_create_uri (const char *name,

                                      const char *uri, direction d);

 extern struct rw *nbd_rw_create_subprocess (const char **argv, size_t argc,

diff --git a/copy/null-ops.c b/copy/null-ops.c

index 1218a62..99cc9a7 100644

--- a/copy/null-ops.c

+++ b/copy/null-ops.c

@@ -45,6 +45,7 @@ null_create (const char *name)

   rw->rw.ops = &null_ops;

   rw->rw.name = name;

   rw->rw.size = INT64_MAX;

+  rw->rw.preferred = 4096;

   return &rw->rw;

 }

diff --git a/copy/pipe-ops.c b/copy/pipe-ops.c

index 3c8b6c2..3815f82 100644

--- a/copy/pipe-ops.c

+++ b/copy/pipe-ops.c

@@ -43,6 +43,7 @@ pipe_create (const char *name, int fd)

   rwp->rw.ops = &pipe_ops;

   rwp->rw.name = name;

   rwp->rw.size = -1;

+  rwp->rw.preferred = 4096;

   rwp->fd = fd;

   return &rwp->rw;

 }

-- 

2.31.1