diff options
Diffstat (limited to 'bin/dd/dd.c')
| -rw-r--r-- | bin/dd/dd.c | 36 |
1 files changed, 21 insertions, 15 deletions
diff --git a/bin/dd/dd.c b/bin/dd/dd.c index 8ae11a7..4c31a5e 100644 --- a/bin/dd/dd.c +++ b/bin/dd/dd.c @@ -77,7 +77,6 @@ STAT st; /* statistics */ void (*cfunc)(void); /* conversion function */ uintmax_t cpy_cnt; /* # of blocks to copy */ static off_t pending = 0; /* pending seek if sparse */ -static off_t last_sp = 0; /* size of last added sparse block */ u_int ddflags = 0; /* conversion options */ size_t cbsz; /* conversion block size */ uintmax_t files_cnt = 1; /* # of files to copy */ @@ -409,6 +408,15 @@ dd_close(void) } if (out.dbcnt || pending) dd_out(1); + + /* + * If the file ends with a hole, ftruncate it to extend its size + * up to the end of the hole (without having to write any data). + */ + if (out.seek_offset > 0 && (out.flags & ISTRUNC)) { + if (ftruncate(out.fd, out.seek_offset) == -1) + err(1, "truncating %s", out.name); + } } void @@ -457,29 +465,27 @@ dd_out(int force) } if (sparse && !force) { pending += cnt; - last_sp = cnt; nw = cnt; } else { if (pending != 0) { - /* If forced to write, and we have no - * data left, we need to write the last - * sparse block explicitly. + /* + * Seek past hole. Note that we need to record the + * reached offset, because we might have no more data + * to write, in which case we'll need to call + * ftruncate to extend the file size. */ - if (force && cnt == 0) { - pending -= last_sp; - assert(outp == out.db); - memset(outp, 0, cnt); - } - if (lseek(out.fd, pending, SEEK_CUR) == - -1) + out.seek_offset = lseek(out.fd, pending, SEEK_CUR); + if (out.seek_offset == -1) err(2, "%s: seek error creating sparse file", out.name); - pending = last_sp = 0; + pending = 0; } - if (cnt) + if (cnt) { nw = write(out.fd, outp, cnt); - else + out.seek_offset = 0; + } else { return; + } } if (nw <= 0) { |
