diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/copy.c | 302 |
1 files changed, 151 insertions, 151 deletions
diff --git a/src/copy.c b/src/copy.c index ba79ed393..af60b572a 100644 --- a/src/copy.c +++ b/src/copy.c @@ -418,178 +418,178 @@ copy_reg (char const *src_name, char const *dst_name, goto close_src_and_dst_desc; } - { - typedef uintptr_t word; - off_t n_read_total = 0; + { + typedef uintptr_t word; + off_t n_read_total = 0; - /* Choose a suitable buffer size; it may be adjusted later. */ - size_t buf_alignment = lcm (getpagesize (), sizeof (word)); - size_t buf_alignment_slop = sizeof (word) + buf_alignment - 1; - size_t buf_size = ST_BLKSIZE (sb); + /* Choose a suitable buffer size; it may be adjusted later. */ + size_t buf_alignment = lcm (getpagesize (), sizeof (word)); + size_t buf_alignment_slop = sizeof (word) + buf_alignment - 1; + size_t buf_size = ST_BLKSIZE (sb); - /* Deal with sparse files. */ - bool last_write_made_hole = false; - bool make_holes = false; + /* Deal with sparse files. */ + bool last_write_made_hole = false; + bool make_holes = false; - if (S_ISREG (sb.st_mode)) - { - /* Even with --sparse=always, try to create holes only - if the destination is a regular file. */ - if (x->sparse_mode == SPARSE_ALWAYS) - make_holes = true; + if (S_ISREG (sb.st_mode)) + { + /* Even with --sparse=always, try to create holes only + if the destination is a regular file. */ + if (x->sparse_mode == SPARSE_ALWAYS) + make_holes = true; #if HAVE_STRUCT_STAT_ST_BLOCKS - /* Use a heuristic to determine whether SRC_NAME contains any sparse - blocks. If the file has fewer blocks than would normally be - needed for a file of its size, then at least one of the blocks in - the file is a hole. */ - if (x->sparse_mode == SPARSE_AUTO && S_ISREG (src_open_sb.st_mode) - && ST_NBLOCKS (src_open_sb) < src_open_sb.st_size / ST_NBLOCKSIZE) - make_holes = true; + /* Use a heuristic to determine whether SRC_NAME contains any sparse + blocks. If the file has fewer blocks than would normally be + needed for a file of its size, then at least one of the blocks in + the file is a hole. */ + if (x->sparse_mode == SPARSE_AUTO && S_ISREG (src_open_sb.st_mode) + && ST_NBLOCKS (src_open_sb) < src_open_sb.st_size / ST_NBLOCKSIZE) + make_holes = true; #endif - } + } - /* If not making a sparse file, try to use a more-efficient - buffer size. */ - if (! make_holes) - { - /* These days there's no point ever messing with buffers smaller - than 8 KiB. It would be nice to configure SMALL_BUF_SIZE - dynamically for this host and pair of files, but there doesn't - seem to be a good way to get readahead info portably. */ - enum { SMALL_BUF_SIZE = 8 * 1024 }; - - /* Compute the least common multiple of the input and output - buffer sizes, adjusting for outlandish values. */ - size_t blcm_max = MIN (SIZE_MAX, SSIZE_MAX) - buf_alignment_slop; - size_t blcm = buffer_lcm (ST_BLKSIZE (src_open_sb), buf_size, - blcm_max); - - /* Do not use a block size that is too small. */ - buf_size = MAX (SMALL_BUF_SIZE, blcm); - - /* Do not bother with a buffer larger than the input file, plus one - byte to make sure the file has not grown while reading it. */ - if (S_ISREG (src_open_sb.st_mode) && src_open_sb.st_size < buf_size) - buf_size = src_open_sb.st_size + 1; - - /* However, stick with a block size that is a positive multiple of - blcm, overriding the above adjustments. Watch out for - overflow. */ - buf_size += blcm - 1; - buf_size -= buf_size % blcm; - if (buf_size == 0 || blcm_max < buf_size) - buf_size = blcm; - } + /* If not making a sparse file, try to use a more-efficient + buffer size. */ + if (! make_holes) + { + /* These days there's no point ever messing with buffers smaller + than 8 KiB. It would be nice to configure SMALL_BUF_SIZE + dynamically for this host and pair of files, but there doesn't + seem to be a good way to get readahead info portably. */ + enum { SMALL_BUF_SIZE = 8 * 1024 }; + + /* Compute the least common multiple of the input and output + buffer sizes, adjusting for outlandish values. */ + size_t blcm_max = MIN (SIZE_MAX, SSIZE_MAX) - buf_alignment_slop; + size_t blcm = buffer_lcm (ST_BLKSIZE (src_open_sb), buf_size, + blcm_max); + + /* Do not use a block size that is too small. */ + buf_size = MAX (SMALL_BUF_SIZE, blcm); + + /* Do not bother with a buffer larger than the input file, plus one + byte to make sure the file has not grown while reading it. */ + if (S_ISREG (src_open_sb.st_mode) && src_open_sb.st_size < buf_size) + buf_size = src_open_sb.st_size + 1; + + /* However, stick with a block size that is a positive multiple of + blcm, overriding the above adjustments. Watch out for + overflow. */ + buf_size += blcm - 1; + buf_size -= buf_size % blcm; + if (buf_size == 0 || blcm_max < buf_size) + buf_size = blcm; + } - /* Make a buffer with space for a sentinel at the end. */ - buf_alloc = xmalloc (buf_size + buf_alignment_slop); - buf = ptr_align (buf_alloc, buf_alignment); + /* Make a buffer with space for a sentinel at the end. */ + buf_alloc = xmalloc (buf_size + buf_alignment_slop); + buf = ptr_align (buf_alloc, buf_alignment); - for (;;) - { - word *wp = NULL; + for (;;) + { + word *wp = NULL; - ssize_t n_read = read (source_desc, buf, buf_size); - if (n_read < 0) - { + ssize_t n_read = read (source_desc, buf, buf_size); + if (n_read < 0) + { #ifdef EINTR - if (errno == EINTR) - continue; + if (errno == EINTR) + continue; #endif - error (0, errno, _("reading %s"), quote (src_name)); - return_val = false; - goto close_src_and_dst_desc; - } - if (n_read == 0) - break; + error (0, errno, _("reading %s"), quote (src_name)); + return_val = false; + goto close_src_and_dst_desc; + } + if (n_read == 0) + break; - n_read_total += n_read; + n_read_total += n_read; - if (make_holes) - { - char *cp; + if (make_holes) + { + char *cp; - /* Sentinel to stop loop. */ - buf[n_read] = '\1'; + /* Sentinel to stop loop. */ + buf[n_read] = '\1'; #ifdef lint - /* Usually, buf[n_read] is not the byte just before a "word" - (aka uintptr_t) boundary. In that case, the word-oriented - test below (*wp++ == 0) would read some uninitialized bytes - after the sentinel. To avoid false-positive reports about - this condition (e.g., from a tool like valgrind), set the - remaining bytes -- to any value. */ - memset (buf + n_read + 1, 0, sizeof (word) - 1); + /* Usually, buf[n_read] is not the byte just before a "word" + (aka uintptr_t) boundary. In that case, the word-oriented + test below (*wp++ == 0) would read some uninitialized bytes + after the sentinel. To avoid false-positive reports about + this condition (e.g., from a tool like valgrind), set the + remaining bytes -- to any value. */ + memset (buf + n_read + 1, 0, sizeof (word) - 1); #endif - /* Find first nonzero *word*, or the word with the sentinel. */ - - wp = (word *) buf; - while (*wp++ == 0) - continue; - - /* Find the first nonzero *byte*, or the sentinel. */ - - cp = (char *) (wp - 1); - while (*cp++ == 0) - continue; - - if (cp <= buf + n_read) - /* Clear to indicate that a normal write is needed. */ - wp = NULL; - else - { - /* We found the sentinel, so the whole input block was zero. - Make a hole. */ - if (lseek (dest_desc, n_read, SEEK_CUR) < 0) - { - error (0, errno, _("cannot lseek %s"), quote (dst_name)); - return_val = false; - goto close_src_and_dst_desc; - } - last_write_made_hole = true; - } - } - - if (!wp) - { - size_t n = n_read; - if (full_write (dest_desc, buf, n) != n) - { - error (0, errno, _("writing %s"), quote (dst_name)); - return_val = false; - goto close_src_and_dst_desc; - } - last_write_made_hole = false; + /* Find first nonzero *word*, or the word with the sentinel. */ + + wp = (word *) buf; + while (*wp++ == 0) + continue; + + /* Find the first nonzero *byte*, or the sentinel. */ + + cp = (char *) (wp - 1); + while (*cp++ == 0) + continue; + + if (cp <= buf + n_read) + /* Clear to indicate that a normal write is needed. */ + wp = NULL; + else + { + /* We found the sentinel, so the whole input block was zero. + Make a hole. */ + if (lseek (dest_desc, n_read, SEEK_CUR) < 0) + { + error (0, errno, _("cannot lseek %s"), quote (dst_name)); + return_val = false; + goto close_src_and_dst_desc; + } + last_write_made_hole = true; + } + } - /* A short read on a regular file means EOF. */ - if (n_read != buf_size && S_ISREG (src_open_sb.st_mode)) - break; - } - } + if (!wp) + { + size_t n = n_read; + if (full_write (dest_desc, buf, n) != n) + { + error (0, errno, _("writing %s"), quote (dst_name)); + return_val = false; + goto close_src_and_dst_desc; + } + last_write_made_hole = false; + + /* A short read on a regular file means EOF. */ + if (n_read != buf_size && S_ISREG (src_open_sb.st_mode)) + break; + } + } - /* If the file ends with a `hole', we need to do something to record - the length of the file. On modern systems, calling ftruncate does - the job. On systems without native ftruncate support, we have to - write a byte at the ending position. Otherwise the kernel would - truncate the file at the end of the last write operation. */ + /* If the file ends with a `hole', we need to do something to record + the length of the file. On modern systems, calling ftruncate does + the job. On systems without native ftruncate support, we have to + write a byte at the ending position. Otherwise the kernel would + truncate the file at the end of the last write operation. */ - if (last_write_made_hole) - { - if (HAVE_FTRUNCATE - ? /* ftruncate sets the file size, - so there is no need for a write. */ - ftruncate (dest_desc, n_read_total) < 0 - : /* Seek backwards one character and write a null. */ - (lseek (dest_desc, (off_t) -1, SEEK_CUR) < 0L - || full_write (dest_desc, "", 1) != 1)) - { - error (0, errno, _("writing %s"), quote (dst_name)); - return_val = false; - goto close_src_and_dst_desc; - } - } - } + if (last_write_made_hole) + { + if (HAVE_FTRUNCATE + ? /* ftruncate sets the file size, + so there is no need for a write. */ + ftruncate (dest_desc, n_read_total) < 0 + : /* Seek backwards one character and write a null. */ + (lseek (dest_desc, (off_t) -1, SEEK_CUR) < 0L + || full_write (dest_desc, "", 1) != 1)) + { + error (0, errno, _("writing %s"), quote (dst_name)); + return_val = false; + goto close_src_and_dst_desc; + } + } + } if (x->preserve_timestamps) { |