diff options
| -rw-r--r-- | coreutils/dd.c | 111 |
1 files changed, 80 insertions, 31 deletions
diff --git a/coreutils/dd.c b/coreutils/dd.c index b5f3cbe..24d7f0b 100644 --- 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] [oflag=seek_bytes|append]" +//usage: " [iflag=skip_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" @@ -82,9 +82,11 @@ //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: "\n oflag=seek_bytes seek=N is in bytes" -//usage: "\n oflag=append Open output file in append mode" +//usage: "\n iflag=direct O_DIRECT input" +//usage: "\n oflag=direct O_DIRECT output" +//usage: "\n iflag=fullblock Read full blocks" +//usage: "\n oflag=append Open output in append mode" //usage: ) //usage: IF_FEATURE_DD_STATUS( //usage: "\n status=noxfer Suppress rate output" @@ -137,16 +139,18 @@ enum { 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, /* end of input flags */ /* start of output flags */ - FLAG_OFLAG_SHIFT = 7, - FLAG_SEEK_BYTES = (1 << 7) * ENABLE_FEATURE_DD_IBS_OBS, - FLAG_APPEND = (1 << 8) * ENABLE_FEATURE_DD_IBS_OBS, + 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, /* end of output flags */ - FLAG_TWOBUFS = (1 << 9) * ENABLE_FEATURE_DD_IBS_OBS, - FLAG_COUNT = 1 << 10, - FLAG_STATUS_NONE = 1 << 11, - FLAG_STATUS_NOXFER = 1 << 12, + FLAG_TWOBUFS = (1 << 11) * ENABLE_FEATURE_DD_IBS_OBS, + FLAG_COUNT = 1 << 12, + FLAG_STATUS_NONE = 1 << 13, + FLAG_STATUS_NOXFER = 1 << 14, }; static void dd_output_status(int UNUSED_PARAM cur_signal) @@ -192,12 +196,50 @@ static void dd_output_status(int UNUSED_PARAM cur_signal) #endif } +#if ENABLE_FEATURE_DD_IBS_OBS +static int clear_O_DIRECT(int fd) +{ + if (errno == EINVAL) { + int fl = fcntl(fd, F_GETFL); + if (fl & O_DIRECT) { + fcntl(fd, F_SETFL, fl & ~O_DIRECT); + return 1; + } + } + return 0; +} +#endif + +static ssize_t dd_read(void *ibuf, size_t ibs) +{ + ssize_t n; + +#if ENABLE_FEATURE_DD_IBS_OBS + read_again: + if (G.flags & FLAG_FULLBLOCK) + n = full_read(ifd, ibuf, ibs); + else +#endif + n = safe_read(ifd, ibuf, ibs); +#if ENABLE_FEATURE_DD_IBS_OBS + if (n < 0 && (G.flags & FLAG_IDIRECT) && clear_O_DIRECT(ifd)) + goto read_again; +#endif + return n; +} + static bool write_and_stats(const void *buf, size_t len, size_t obs, const char *filename) { ssize_t n; + IF_FEATURE_DD_IBS_OBS(write_again:) n = full_write(ofd, buf, len); +#if ENABLE_FEATURE_DD_IBS_OBS + if (n < 0 && (G.flags & FLAG_ODIRECT) && clear_O_DIRECT(ofd)) + goto write_again; +#endif + #if ENABLE_FEATURE_DD_THIRD_STATUS_LINE if (n > 0) G.total_bytes += n; @@ -254,6 +296,14 @@ static int parse_comma_flags(char *val, const char *words, const char *error_in) } #endif +static void *alloc_buf(size_t size) +{ + /* Important for "{i,o}flag=direct" - buffers must be page aligned */ + if (size >= bb_getpagesize()) + return xmmap_anon(size); + return xmalloc(size); +} + int dd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int dd_main(int argc UNUSED_PARAM, char **argv) { @@ -267,9 +317,9 @@ 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""fullblock\0"; + "skip_bytes\0""fullblock\0""direct\0"; static const char oflag_words[] ALIGN1 = - "seek_bytes\0append\0"; + "seek_bytes\0append\0""direct\0"; #endif #if ENABLE_FEATURE_DD_STATUS static const char status_words[] ALIGN1 = @@ -310,7 +360,9 @@ int dd_main(int argc UNUSED_PARAM, char **argv) //swab swap every pair of input bytes: will abort on non-even reads OP_iflag_skip_bytes, OP_iflag_fullblock, + OP_iflag_direct, OP_oflag_seek_bytes, + OP_oflag_direct, #endif }; smallint exitcode = EXIT_FAILURE; @@ -426,13 +478,12 @@ int dd_main(int argc UNUSED_PARAM, char **argv) #endif } /* end of "for (argv[i])" */ -//XXX:FIXME for huge ibs or obs, malloc'ing them isn't the brightest idea ever - ibuf = xmalloc(ibs); + ibuf = alloc_buf(ibs); obuf = ibuf; #if ENABLE_FEATURE_DD_IBS_OBS if (ibs != obs) { G.flags |= FLAG_TWOBUFS; - obuf = xmalloc(obs); + obuf = alloc_buf(obs); } #endif @@ -444,7 +495,12 @@ int dd_main(int argc UNUSED_PARAM, char **argv) #endif if (infile) { - xmove_fd(xopen(infile, O_RDONLY), ifd); + int iflag = O_RDONLY; +#if ENABLE_FEATURE_DD_IBS_OBS + if (G.flags & FLAG_IDIRECT) + iflag |= O_DIRECT; +#endif + xmove_fd(xopen(infile, iflag), ifd); } else { infile = bb_msg_standard_input; } @@ -455,7 +511,10 @@ int dd_main(int argc UNUSED_PARAM, char **argv) oflag |= O_TRUNC; if (G.flags & FLAG_APPEND) oflag |= O_APPEND; - +#if ENABLE_FEATURE_DD_IBS_OBS + if (G.flags & FLAG_ODIRECT) + oflag |= O_DIRECT; +#endif xmove_fd(xopen(outfile, oflag), ofd); if (seek && !(G.flags & FLAG_NOTRUNC)) { @@ -478,13 +537,7 @@ 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; -#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); + ssize_t n = dd_read(ibuf, blocksz); if (n < 0) goto die_infile; if (n == 0) @@ -499,13 +552,7 @@ int dd_main(int argc UNUSED_PARAM, char **argv) } while (!(G.flags & FLAG_COUNT) || (G.in_full + G.in_part != count)) { - ssize_t n; -#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); + ssize_t n = dd_read(ibuf, ibs); if (n == 0) break; if (n < 0) { @@ -600,11 +647,13 @@ int dd_main(int argc UNUSED_PARAM, char **argv) if (!ENABLE_FEATURE_DD_STATUS || !(G.flags & FLAG_STATUS_NONE)) dd_output_status(0); +#if 0 /* can't just free(), they can be mmap()ed */ if (ENABLE_FEATURE_CLEAN_UP) { free(obuf); if (G.flags & FLAG_TWOBUFS) free(ibuf); } +#endif return exitcode; } |