2 files changed, 26 insertions, 12 deletions

diff --git a/coreutils/dd.c b/coreutils/dd.c
index 38b2a6aa1..0f130bcad 100644
--- a/coreutils/dd.c
+++ b/coreutils/dd.c
@@ -37,7 +37,7 @@
 //config:       elapsed time and speed.
 //config:
 //config:config FEATURE_DD_IBS_OBS
-//config:       bool "Enable ibs, obs and conv options"
+//config:       bool "Enable ibs, obs, iflag and conv options"
 //config:       default y
 //config:       depends on DD
 //config:       help
@@ -57,7 +57,7 @@
 
 //usage:#define dd_trivial_usage
 //usage:       "[if=FILE] [of=FILE] " IF_FEATURE_DD_IBS_OBS("[ibs=N] [obs=N] ") "[bs=N] [count=N] [skip=N]\n"
-//usage:       "        [seek=N]" IF_FEATURE_DD_IBS_OBS(" [conv=notrunc|noerror|sync|fsync] [iflag=skip_bytes]")
+//usage:       "        [seek=N]" IF_FEATURE_DD_IBS_OBS(" [conv=notrunc|noerror|sync|fsync] [iflag=skip_bytes|fullblock]")
 //usage:#define dd_full_usage "\n\n"
 //usage:       "Copy a file with converting and formatting\n"
 //usage:     "\n        if=FILE         Read from FILE instead of stdin"
@@ -79,6 +79,7 @@
 //usage:     "\n        conv=fsync      Physically write data out before finishing"
 //usage:     "\n        conv=swab       Swap every pair of bytes"
 //usage:     "\n        iflag=skip_bytes        skip=N is in bytes"
+//usage:     "\n        iflag=fullblock Read full blocks"
 //usage:        )
 //usage:        IF_FEATURE_DD_STATUS(
 //usage:     "\n        status=noxfer   Suppress rate output"
@@ -130,11 +131,12 @@ enum {
         /* start of input flags */
         FLAG_IFLAG_SHIFT = 5,
         FLAG_SKIP_BYTES = (1 << 5) * ENABLE_FEATURE_DD_IBS_OBS,
+        FLAG_FULLBLOCK = (1 << 6) * ENABLE_FEATURE_DD_IBS_OBS,
         /* end of input flags */
-        FLAG_TWOBUFS = (1 << 6) * ENABLE_FEATURE_DD_IBS_OBS,
-        FLAG_COUNT   = 1 << 7,
-        FLAG_STATUS_NONE = 1 << 8,
-        FLAG_STATUS_NOXFER = 1 << 9,
+        FLAG_TWOBUFS = (1 << 7) * ENABLE_FEATURE_DD_IBS_OBS,
+        FLAG_COUNT   = 1 << 8,
+        FLAG_STATUS_NONE = 1 << 9,
+        FLAG_STATUS_NOXFER = 1 << 10,
 };
 
 static void dd_output_status(int UNUSED_PARAM cur_signal)
@@ -255,7 +257,7 @@ int dd_main(int argc UNUSED_PARAM, char **argv)
         static const char conv_words[] ALIGN1 =
                 "notrunc\0""sync\0""noerror\0""fsync\0""swab\0";
         static const char iflag_words[] ALIGN1 =
-                "skip_bytes\0";
+                "skip_bytes\0""fullblock\0";
 #endif
 #if ENABLE_FEATURE_DD_STATUS
         static const char status_words[] ALIGN1 =
@@ -294,6 +296,7 @@ int dd_main(int argc UNUSED_PARAM, char **argv)
         /* Partially implemented: */
         //swab          swap every pair of input bytes: will abort on non-even reads
                 OP_iflag_skip_bytes,
+                OP_iflag_fullblock,
 #endif
         };
         smallint exitcode = EXIT_FAILURE;
@@ -454,7 +457,13 @@ int dd_main(int argc UNUSED_PARAM, char **argv)
                 size_t blocksz = (G.flags & FLAG_SKIP_BYTES) ? 1 : ibs;
                 if (lseek(ifd, skip * blocksz, SEEK_CUR) < 0) {
                         do {
-                                ssize_t n = safe_read(ifd, ibuf, blocksz);
+                                ssize_t n;
+#if ENABLE_FEATURE_DD_IBS_OBS
+                                if (G.flags & FLAG_FULLBLOCK)
+                                        n = full_read(ifd, ibuf, blocksz);
+                                else
+#endif
+                                        n = safe_read(ifd, ibuf, blocksz);
                                 if (n < 0)
                                         goto die_infile;
                                 if (n == 0)
@@ -469,8 +478,12 @@ int dd_main(int argc UNUSED_PARAM, char **argv)
 
         while (!(G.flags & FLAG_COUNT) || (G.in_full + G.in_part != count)) {
                 ssize_t n;
-
-                n = safe_read(ifd, ibuf, ibs);
+#if ENABLE_FEATURE_DD_IBS_OBS
+                if (G.flags & FLAG_FULLBLOCK)
+                        n = full_read(ifd, ibuf, ibs);
+                else
+#endif
+                        n = safe_read(ifd, ibuf, ibs);
                 if (n == 0)
                         break;
                 if (n < 0) {
diff --git a/docs/posix_conformance.txt b/docs/posix_conformance.txt
index 8b9112020..cdf89b744 100644
--- a/docs/posix_conformance.txt
+++ b/docs/posix_conformance.txt
@@ -178,9 +178,10 @@ dd POSIX options:
   conv=noerror    |  yes   |           |
   conv=notrunc    |  yes   |           |
   conv=sync       |  yes   |           |
+dd compatibility options:
+  conv=fsync      |  yes   |           |
   iflag=skip_bytes|  yes   |           |
-dd Busybox specific options:
- conv=fsync
+  iflag=fullblock |  yes   |           |
 
 df POSIX options
  option           | exists | compliant | remarks