emo/busybox
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

dd: fix conv=noerror w/o sync to not write out zeroed blocks

Browse Source 
function                                             old     new   delta
dd_main                                             1480    1463     -17

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2009-09-18 20:49:36 +02:00
parent ae0045e31a
commit f00cfdfae5
1 changed files with 6 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
coreutils/dd.c
View File

@ -286,25 +286,26 @@ int dd_main(int argc UNUSED_PARAM, char **argv)
} }
while (!(flags & FLAG_COUNT) || (G.in_full + G.in_part != count)) { while (!(flags & FLAG_COUNT) || (G.in_full + G.in_part != count)) {
if (flags & FLAG_NOERROR) /* Pre-zero the buffer if conv=noerror */
memset(ibuf, 0, ibs);
n = safe_read(ifd, ibuf, ibs); n = safe_read(ifd, ibuf, ibs);
if (n == 0) if (n == 0)
break; break;
if (n < 0) { if (n < 0) {
/* "Bad block" */
if (!(flags & FLAG_NOERROR)) if (!(flags & FLAG_NOERROR))
goto die_infile; goto die_infile;
n = ibs;
bb_simple_perror_msg(infile); bb_simple_perror_msg(infile);
/* GNU dd with conv=noerror skips over "bad blocks" */ /* GNU dd with conv=noerror skips over bad blocks */
xlseek(ifd, ibs, SEEK_CUR); xlseek(ifd, ibs, SEEK_CUR);
/* conv=noerror,sync writes NULs,
* conv=noerror just ignores input bad blocks */
n = 0;
} }
if ((size_t)n == ibs) if ((size_t)n == ibs)
G.in_full++; G.in_full++;
else { else {
G.in_part++; G.in_part++;
if (flags & FLAG_SYNC) { if (flags & FLAG_SYNC) {
memset(ibuf + n, '\0', ibs - n); memset(ibuf + n, 0, ibs - n);
n = ibs; n = ibs;
} }
} }