diff options
Diffstat (limited to 'src/shred.c')
| -rw-r--r-- | src/shred.c | 62 |
1 files changed, 37 insertions, 25 deletions
diff --git a/src/shred.c b/src/shred.c index 9b869cdcb..5c9765cd2 100644 --- a/src/shred.c +++ b/src/shred.c @@ -359,19 +359,18 @@ dopass (int fd, char const *qname, off_t *sizep, int type, size_t soff; /* Offset into buffer for next write */ ssize_t ssize; /* Return value from write */ - /* Fill pattern buffer. Aligning it to a 32-bit boundary speeds up randread - in some cases. */ - typedef uint32_t fill_pattern_buffer[3 * 1024]; - union - { - fill_pattern_buffer buffer; - char c[sizeof (fill_pattern_buffer)]; - unsigned char u[sizeof (fill_pattern_buffer)]; - } r; - - off_t sizeof_r = sizeof r; + /* Fill pattern buffer. Aligning it to a page so we can do direct I/O. */ + size_t page_size = getpagesize (); +#define OUTPUT_SIZE (12 * 1024) +#define PAGE_ALIGN_SLOP (page_size - 1) /* So directio works */ +#define FILLPATTERN_SIZE (((OUTPUT_SIZE + 2) / 3) * 3) /* Multiple of 3 */ +#define PATTERNBUF_SIZE (PAGE_ALIGN_SLOP + FILLPATTERN_SIZE) + void *fill_pattern_mem = xmalloc (PATTERNBUF_SIZE); + unsigned char *pbuf = ptr_align (fill_pattern_mem, page_size); + char pass_string[PASS_NAME_SIZE]; /* Name of current pass */ bool write_error = false; + bool other_error = false; bool first_write = true; /* Printable previous offset into the file */ @@ -381,15 +380,16 @@ dopass (int fd, char const *qname, off_t *sizep, int type, if (lseek (fd, 0, SEEK_SET) == -1) { error (0, errno, _("%s: cannot rewind"), qname); - return -1; + other_error = true; + goto free_pattern_mem; } /* Constant fill patterns need only be set up once. */ if (type >= 0) { - lim = (0 <= size && size < sizeof_r ? size : sizeof_r); - fillpattern (type, r.u, lim); - passname (r.u, pass_string); + lim = (0 <= size && size < FILLPATTERN_SIZE ? size : FILLPATTERN_SIZE); + fillpattern (type, pbuf, lim); + passname (pbuf, pass_string); } else { @@ -408,8 +408,8 @@ dopass (int fd, char const *qname, off_t *sizep, int type, while (true) { /* How much to write this time? */ - lim = sizeof r; - if (0 <= size && size - offset < sizeof_r) + lim = OUTPUT_SIZE; + if (0 <= size && size - offset < OUTPUT_SIZE) { if (size < offset) break; @@ -418,11 +418,11 @@ dopass (int fd, char const *qname, off_t *sizep, int type, break; } if (type < 0) - randread (s, &r, lim); + randread (s, pbuf, lim); /* Loop to retry partial writes. */ for (soff = 0; soff < lim; soff += ssize, first_write = false) { - ssize = write (fd, r.c + soff, lim - soff); + ssize = write (fd, pbuf + soff, lim - soff); if (ssize <= 0) { if (size < 0 && (ssize == 0 || errno == ENOSPC)) @@ -456,7 +456,7 @@ dopass (int fd, char const *qname, off_t *sizep, int type, out. Thus, it shouldn't give up on bad blocks. This code works because lim is always a multiple of SECTOR_SIZE, except at the end. */ - verify (sizeof r % SECTOR_SIZE == 0); + verify (OUTPUT_SIZE % SECTOR_SIZE == 0); if (errnum == EIO && 0 <= size && (soff | SECTOR_MASK) < lim) { size_t soff1 = (soff | SECTOR_MASK) + 1; @@ -469,7 +469,8 @@ dopass (int fd, char const *qname, off_t *sizep, int type, } error (0, errno, _("%s: lseek failed"), qname); } - return -1; + other_error = true; + goto free_pattern_mem; } } } @@ -479,7 +480,8 @@ dopass (int fd, char const *qname, off_t *sizep, int type, if (offset > OFF_T_MAX - (off_t) soff) { error (0, 0, _("%s: file too large"), qname); - return -1; + other_error = true; + goto free_pattern_mem; } offset += soff; @@ -536,7 +538,10 @@ dopass (int fd, char const *qname, off_t *sizep, int type, if (dosync (fd, qname) != 0) { if (errno != EIO) - return -1; + { + other_error = true; + goto free_pattern_mem; + } write_error = true; } } @@ -547,11 +552,18 @@ dopass (int fd, char const *qname, off_t *sizep, int type, if (dosync (fd, qname) != 0) { if (errno != EIO) - return -1; + { + other_error = true; + goto free_pattern_mem; + } write_error = true; } - return write_error; +free_pattern_mem: + memset (pbuf, 0, FILLPATTERN_SIZE); + free (fill_pattern_mem); + + return other_error ? -1 : write_error; } /* |