e2fsprogs: let debugfs do sparse copy

Let debugfs do sparse copy when src is a sparse file, just like
"cp --sparse=auto"

This patch has been reviewed by the linux-ext4 mailing list, but isn't
merged atm.

[YOCTO #3848]

(From OE-Core rev: 723adaf8fbba61b7f1adc8e4a13ddf1cfb5c0bcf)

Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

diff --git a/meta/recipes-devtools/e2fsprogs/e2fsprogs-1.42.8/debugfs-sparse-copy.patch b/meta/recipes-devtools/e2fsprogs/e2fsprogs-1.42.8/debugfs-sparse-copy.patch
new file mode 100644 (file)
index 0000000..0712470
--- /dev/null
+++ b/meta/recipes-devtools/e2fsprogs/e2fsprogs-1.42.8/debugfs-sparse-copy.patch
@@ -0,0 +1,148 @@
+debugfs.c: do sparse copy when src is a sparse file
+
+Let debugfs do sparse copy when src is a sparse file, just like
+"cp --sparse=auto"
+
+* For the:
+  #define IO_BUFSIZE 64*1024
+  this is a suggested value from gnu coreutils:
+  http://git.savannah.gnu.org/gitweb/?p=coreutils.git;a=blob;f=src/ioblksize.h;h=1ae93255e7d0ccf0855208c7ae5888209997bf16;hb=HEAD
+
+* Use malloc() to allocate memory for the buffer since put 64K (or
+  more) on the stack seems not a good idea.
+
+Upstream-Status: Submitted
+
+Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
+Acked-by: Darren Hart <dvhart@linux.intel.com>
+---
+ debugfs/debugfs.c |   62 +++++++++++++++++++++++++++++++++++++++++++++++++----
+ 1 file changed, 58 insertions(+), 4 deletions(-)
+
+diff --git a/debugfs/debugfs.c b/debugfs/debugfs.c
+--- a/debugfs/debugfs.c
++++ b/debugfs/debugfs.c
+@@ -41,6 +41,16 @@ extern char *optarg;
+ #define BUFSIZ 8192
+ #endif
+ 
++/* 64KiB is the minimium blksize to best minimize system call overhead. */
++#ifndef IO_BUFSIZE
++#define IO_BUFSIZE 64*1024
++#endif
++
++/* Block size for `st_blocks' */
++#ifndef S_BLKSIZE
++#define S_BLKSIZE 512
++#endif
++
+ ss_request_table *extra_cmds;
+ const char *debug_prog_name;
+ int sci_idx;
+@@ -1563,22 +1573,37 @@ void do_find_free_inode(int argc, char *argv[])
+ }
+ 
+ #ifndef READ_ONLY
+-static errcode_t copy_file(int fd, ext2_ino_t newfile)
++static errcode_t copy_file(int fd, ext2_ino_t newfile, int bufsize, int make_holes)
+ {
+       ext2_file_t     e2_file;
+       errcode_t       retval;
+       int             got;
+       unsigned int    written;
+-      char            buf[8192];
++      char            *buf;
+       char            *ptr;
++      char            *zero_buf;
++      int             cmp;
+ 
+       retval = ext2fs_file_open(current_fs, newfile,
+                                 EXT2_FILE_WRITE, &e2_file);
+       if (retval)
+               return retval;
+ 
++      if (!(buf = (char *) malloc(bufsize))){
++              com_err("copy_file", errno, "can't allocate buffer\n");
++              return;
++      }
++
++      /* This is used for checking whether the whole block is zero */
++      retval = ext2fs_get_memzero(bufsize, &zero_buf);
++      if (retval) {
++              com_err("copy_file", retval, "can't allocate buffer\n");
++              free(buf);
++              return retval;
++      }
++
+       while (1) {
+-              got = read(fd, buf, sizeof(buf));
++              got = read(fd, buf, bufsize);
+               if (got == 0)
+                       break;
+               if (got < 0) {
+@@ -1586,6 +1611,21 @@ static errcode_t copy_file(int fd, ext2_ino_t newfile)
+                       goto fail;
+               }
+               ptr = buf;
++
++              /* Sparse copy */
++              if (make_holes) {
++                      /* Check whether all is zero */
++                      cmp = memcmp(ptr, zero_buf, got);
++                      if (cmp == 0) {
++                               /* The whole block is zero, make a hole */
++                              retval = ext2fs_file_lseek(e2_file, got, EXT2_SEEK_CUR, NULL);
++                              if (retval)
++                                      goto fail;
++                              got = 0;
++                      }
++              }
++
++              /* Normal copy */
+               while (got > 0) {
+                       retval = ext2fs_file_write(e2_file, ptr,
+                                                  got, &written);
+@@ -1596,10 +1636,14 @@ static errcode_t copy_file(int fd, ext2_ino_t newfile)
+                       ptr += written;
+               }
+       }
++      free(buf);
++      ext2fs_free_mem(&zero_buf);
+       retval = ext2fs_file_close(e2_file);
+       return retval;
+ 
+ fail:
++      free(buf);
++      ext2fs_free_mem(&zero_buf);
+       (void) ext2fs_file_close(e2_file);
+       return retval;
+ }
+@@ -1612,6 +1656,8 @@ void do_write(int argc, char *argv[])
+       ext2_ino_t      newfile;
+       errcode_t       retval;
+       struct ext2_inode inode;
++      int             bufsize = IO_BUFSIZE;
++      int             make_holes = 0;
+ 
+       if (common_args_process(argc, argv, 3, 3, "write",
+                               "<native file> <new file>", CHECK_FS_RW))
+@@ -1687,7 +1733,15 @@ void do_write(int argc, char *argv[])
+               return;
+       }
+       if (LINUX_S_ISREG(inode.i_mode)) {
+-              retval = copy_file(fd, newfile);
++              if (statbuf.st_blocks < statbuf.st_size / S_BLKSIZE) {
++                      make_holes = 1;
++                      /*
++                       * Use I/O blocksize as buffer size when
++                       * copying sparse files.
++                       */
++                      bufsize = statbuf.st_blksize;
++              }
++              retval = copy_file(fd, newfile, bufsize, make_holes);
+               if (retval)
+                       com_err("copy_file", retval, 0);
+       }
+-- 
+1.7.10.4
+

diff --git a/meta/recipes-devtools/e2fsprogs/e2fsprogs_1.42.8.bb b/meta/recipes-devtools/e2fsprogs/e2fsprogs_1.42.8.bb
index 319728e..22618e6 100644 (file)
--- a/meta/recipes-devtools/e2fsprogs/e2fsprogs_1.42.8.bb
+++ b/meta/recipes-devtools/e2fsprogs/e2fsprogs_1.42.8.bb
@@ -4,6 +4,7 @@ require e2fsprogs.inc
 SRC_URI += "file://acinclude.m4 \
             file://remove.ldconfig.call.patch \
             file://debugfs-too-short.patch \
+            file://debugfs-sparse-copy.patch \
 "
 
 SRC_URI[md5sum] = "8ef664b6eb698aa6b733df59b17b9ed4"