[PATCH 21.02] busybox: backport dd support for iflag=count_bytes
Rafał Miłecki
zajec5 at gmail.com
Thu Dec 16 03:36:16 PST 2021
From: Rafał Miłecki <rafal at milecki.pl>
It's very useful flag for handling various formats in sysupgrade. This
commits comes from 1.34.0 release.
Signed-off-by: Rafał Miłecki <rafal at milecki.pl>
---
.../001-dd-support-iflag-count_bytes.patch | 140 ++++++++++++++++++
1 file changed, 140 insertions(+)
create mode 100644 package/utils/busybox/patches/001-dd-support-iflag-count_bytes.patch
diff --git a/package/utils/busybox/patches/001-dd-support-iflag-count_bytes.patch b/package/utils/busybox/patches/001-dd-support-iflag-count_bytes.patch
new file mode 100644
index 0000000000..c195c10cf1
--- /dev/null
+++ b/package/utils/busybox/patches/001-dd-support-iflag-count_bytes.patch
@@ -0,0 +1,140 @@
+From 4eb46e1be6d88eaf077252ce93127ebf00aa8ef2 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal at milecki.pl>
+Date: Wed, 24 Mar 2021 16:01:42 +0100
+Subject: [PATCH] dd: support iflag=count_bytes
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+It allows passing amount of bytes in the count=
+
+function old new delta
+packed_usage 33599 33617 +18
+static.iflag_words 29 41 +12
+dd_main 1601 1607 +6
+------------------------------------------------------------------------------
+(add/remove: 0/0 grow/shrink: 3/0 up/down: 36/0) Total: 36 bytes
+
+Signed-off-by: Rafał Miłecki <rafal at milecki.pl>
+Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
+---
+ coreutils/dd.c | 50 ++++++++++++++++++++++++-------------
+ testsuite/dd/dd-count-bytes | 1 +
+ 2 files changed, 33 insertions(+), 18 deletions(-)
+ create mode 100644 testsuite/dd/dd-count-bytes
+
+--- a/coreutils/dd.c
++++ b/coreutils/dd.c
+@@ -59,7 +59,7 @@
+ //usage: "[if=FILE] [of=FILE] [" IF_FEATURE_DD_IBS_OBS("ibs=N obs=N/") "bs=N] [count=N] [skip=N] [seek=N]\n"
+ //usage: IF_FEATURE_DD_IBS_OBS(
+ //usage: " [conv=notrunc|noerror|sync|fsync]\n"
+-//usage: " [iflag=skip_bytes|fullblock|direct] [oflag=seek_bytes|append|direct]"
++//usage: " [iflag=skip_bytes|count_bytes|fullblock|direct] [oflag=seek_bytes|append|direct]"
+ //usage: )
+ //usage:#define dd_full_usage "\n\n"
+ //usage: "Copy a file with converting and formatting\n"
+@@ -82,6 +82,7 @@
+ //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=count_bytes count=N is in bytes"
+ //usage: "\n oflag=seek_bytes seek=N is in bytes"
+ //usage: "\n iflag=direct O_DIRECT input"
+ //usage: "\n oflag=direct O_DIRECT output"
+@@ -136,21 +137,22 @@ enum {
+ FLAG_SWAB = (1 << 4) * ENABLE_FEATURE_DD_IBS_OBS,
+ /* end of conv flags */
+ /* 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,
+- FLAG_IDIRECT = (1 << 7) * ENABLE_FEATURE_DD_IBS_OBS,
++ FLAG_IFLAG_SHIFT = 5,
++ FLAG_SKIP_BYTES = (1 << 5) * ENABLE_FEATURE_DD_IBS_OBS,
++ FLAG_COUNT_BYTES = (1 << 6) * ENABLE_FEATURE_DD_IBS_OBS,
++ FLAG_FULLBLOCK = (1 << 7) * ENABLE_FEATURE_DD_IBS_OBS,
++ FLAG_IDIRECT = (1 << 8) * ENABLE_FEATURE_DD_IBS_OBS,
+ /* end of input flags */
+ /* start of output flags */
+- FLAG_OFLAG_SHIFT = 8,
+- FLAG_SEEK_BYTES = (1 << 8) * ENABLE_FEATURE_DD_IBS_OBS,
+- FLAG_APPEND = (1 << 9) * ENABLE_FEATURE_DD_IBS_OBS,
+- FLAG_ODIRECT = (1 << 10) * ENABLE_FEATURE_DD_IBS_OBS,
++ FLAG_OFLAG_SHIFT = 9,
++ FLAG_SEEK_BYTES = (1 << 9) * ENABLE_FEATURE_DD_IBS_OBS,
++ FLAG_APPEND = (1 << 10) * ENABLE_FEATURE_DD_IBS_OBS,
++ FLAG_ODIRECT = (1 << 11) * ENABLE_FEATURE_DD_IBS_OBS,
+ /* end of output flags */
+- FLAG_TWOBUFS = (1 << 11) * ENABLE_FEATURE_DD_IBS_OBS,
+- FLAG_COUNT = 1 << 12,
+- FLAG_STATUS_NONE = 1 << 13,
+- FLAG_STATUS_NOXFER = 1 << 14,
++ FLAG_TWOBUFS = (1 << 12) * ENABLE_FEATURE_DD_IBS_OBS,
++ FLAG_COUNT = 1 << 13,
++ FLAG_STATUS_NONE = 1 << 14,
++ FLAG_STATUS_NOXFER = 1 << 15,
+ };
+
+ static void dd_output_status(int UNUSED_PARAM cur_signal)
+@@ -175,8 +177,9 @@ static void dd_output_status(int UNUSED_
+ //So far we react to it (we print the stats),
+ //status=none only suppresses final, non-USR1 generated status message.
+ # endif
+- fprintf(stderr, "%llu bytes (%sB) copied, ",
+- G.total_bytes,
++ fprintf(stderr, /*G.total_bytes < 1024
++ ? "%llu bytes copied, " : */ "%llu bytes (%sB) copied, "
++ , G.total_bytes,
+ /* show fractional digit, use suffixes */
+ make_human_readable_str(G.total_bytes, 1, 0)
+ );
+@@ -317,7 +320,7 @@ int dd_main(int argc UNUSED_PARAM, char
+ 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""fullblock\0""direct\0";
++ "skip_bytes\0""count_bytes\0""fullblock\0""direct\0";
+ static const char oflag_words[] ALIGN1 =
+ "seek_bytes\0append\0""direct\0";
+ #endif
+@@ -359,6 +362,7 @@ int dd_main(int argc UNUSED_PARAM, char
+ /* Partially implemented: */
+ //swab swap every pair of input bytes: will abort on non-even reads
+ OP_iflag_skip_bytes,
++ OP_iflag_count_bytes,
+ OP_iflag_fullblock,
+ OP_iflag_direct,
+ OP_oflag_seek_bytes,
+@@ -551,8 +555,17 @@ int dd_main(int argc UNUSED_PARAM, char
+ goto die_outfile;
+ }
+
+- while (!(G.flags & FLAG_COUNT) || (G.in_full + G.in_part != count)) {
+- ssize_t n = dd_read(ibuf, ibs);
++ while (1) {
++ ssize_t n = ibs;
++
++ if (G.flags & FLAG_COUNT) {
++ if (count == 0)
++ break;
++ if ((G.flags & FLAG_COUNT_BYTES) && count < ibs)
++ n = count;
++ }
++
++ n = dd_read(ibuf, n);
+ if (n == 0)
+ break;
+ if (n < 0) {
+@@ -587,6 +600,7 @@ int dd_main(int argc UNUSED_PARAM, char
+ p16++;
+ }
+ }
++ count -= (G.flags & FLAG_COUNT_BYTES) ? n : 1;
+ if ((size_t)n == ibs)
+ G.in_full++;
+ else {
+--- /dev/null
++++ b/testsuite/dd/dd-count-bytes
+@@ -0,0 +1 @@
++test "$(echo I WANT | busybox dd count=3 iflag=count_bytes 2>/dev/null)" = "I W"
--
2.31.1
More information about the openwrt-devel
mailing list