}
/*
- * Do pass number k of n, writing "size" bytes of the given pattern "type"
- * to the file descriptor fd. Qname, k and n are passed in only for verbose
- * progress message purposes. If n == 0, no progress messages are printed.
+ * Do pass number K of N, writing *SIZEP bytes of the given pattern TYPE
+ * to the file descriptor FD. K and N are passed in only for verbose
+ * progress message purposes. If N == 0, no progress messages are printed.
*
- * If *sizep == -1, the size is unknown, and it will be filled in as soon
- * as writing fails.
+ * If *SIZEP == -1, the size is unknown, and it will be filled in as soon
+ * as writing fails with ENOSPC.
*
* Return 1 on write error, -1 on other error, 0 on success.
*/
size_t soff; /* Offset into buffer for next write */
ssize_t ssize; /* Return value from write */
- /* Do nothing for --size=0 or regular empty files. */
- if (size == 0)
- return 0;
-
/* Fill pattern buffer. Aligning it to a page so we can do direct I/O. */
size_t page_size = getpagesize ();
#define PERIODIC_OUTPUT_SIZE (60 * 1024)
char pass_string[PASS_NAME_SIZE]; /* Name of current pass */
bool write_error = false;
bool other_error = false;
- bool tried_without_directio = false;
/* Printable previous offset into the file */
char previous_offset_buf[LONGEST_HUMAN_READABLE + 1];
char const *previous_human_offset IF_LINT ( = 0);
+ /* As a performance tweak, avoid direct I/O for small sizes,
+ as it's just a performance rather then security consideration,
+ and direct I/O can often be unsupported for small non aligned sizes. */
+ bool try_without_directio = 0 < size && size < output_size;
+ if (! try_without_directio)
+ direct_mode (fd, true);
+
if (! dorewind (fd, st))
{
error (0, errno, _("%s: cannot rewind"), qname);
at all on some (file) systems, or with the current size.
I.E. a specified --size that is not aligned, or when
dealing with slop at the end of a file with --exact. */
- if (k == 1 && !tried_without_directio && errno == EINVAL)
+ if (! try_without_directio && errno == EINVAL)
{
direct_mode (fd, false);
ssize = 0;
- tried_without_directio = true;
+ try_without_directio = true;
continue;
}
error (0, errnum, _("%s: error writing at offset %s"),
{
size_t i;
struct stat st;
- off_t size; /* Size to write, size to read */
- unsigned long int n; /* Number of passes for printing purposes */
+ off_t size; /* Size to write, size to read */
+ off_t i_size = 0; /* For small files, initial size to overwrite inode */
+ unsigned long int n; /* Number of passes for printing purposes */
int *passarray;
bool ok = true;
struct randread_source *rs;
- n = 0; /* dopass takes n -- 0 to mean "don't print progress" */
+ n = 0; /* dopass takes n == 0 to mean "don't print progress" */
if (flags->verbose)
n = flags->n_iterations + flags->zero_fill;
error (0, 0, _("%s: invalid file type"), qname);
return false;
}
-
- direct_mode (fd, true);
+ else if (S_ISREG (st.st_mode) && st.st_size < 0)
+ {
+ error (0, 0, _("%s: file has negative size"), qname);
+ return false;
+ }
/* Allocate pass array */
passarray = xnmalloc (flags->n_iterations, sizeof *passarray);
if (S_ISREG (st.st_mode))
{
size = st.st_size;
- if (size < 0)
- {
- error (0, 0, _("%s: file has negative size"), qname);
- return false;
- }
if (! flags->exact)
{
- /* Round up to the nearest blocksize to clear slack space. */
+ /* Round up to the nearest block size to clear slack space. */
off_t remainder = size % ST_BLKSIZE (st);
+ if (size && size < ST_BLKSIZE (st))
+ i_size = size;
if (remainder != 0)
{
off_t size_incr = ST_BLKSIZE (st) - remainder;
- if (! INT_ADD_OVERFLOW (size, size_incr))
- size += size_incr;
- else
- size = OFF_T_MAX;
+ size += MIN (size_incr, OFF_T_MAX - size);
}
}
}
}
}
}
+ else if (S_ISREG (st.st_mode)
+ && st.st_size < MIN (ST_BLKSIZE (st), size))
+ i_size = st.st_size;
/* Schedule the passes in random order. */
genpattern (passarray, flags->n_iterations, s);
rs = randint_get_source (s);
- /* Do the work */
- for (i = 0; i < flags->n_iterations; i++)
+ while (true)
{
- int err = dopass (fd, &st, qname, &size, passarray[i], rs, i + 1, n);
- if (err)
+ off_t pass_size;
+ unsigned long int pn = n;
+
+ if (i_size)
{
- if (err < 0)
- {
- memset (passarray, 0, flags->n_iterations * sizeof (int));
- free (passarray);
- return false;
- }
- ok = false;
+ pass_size = i_size;
+ i_size = 0;
+ pn = 0;
}
- }
-
- memset (passarray, 0, flags->n_iterations * sizeof (int));
- free (passarray);
+ else if (size)
+ {
+ pass_size = size;
+ size = 0;
+ }
+ /* TODO: consider handling tail packing by
+ writing the tail padding as a separate pass,
+ (that would not rewind). */
+ else
+ break;
- if (flags->zero_fill)
- {
- int err = dopass (fd, &st, qname, &size, 0, rs,
- flags->n_iterations + 1, n);
- if (err)
+ for (i = 0; i < flags->n_iterations + flags->zero_fill; i++)
{
- if (err < 0)
- return false;
- ok = false;
+ int err = 0;
+ int type = i < flags->n_iterations ? passarray[i] : 0;
+
+ err = dopass (fd, &st, qname, &pass_size, type, rs, i + 1, pn);
+
+ if (err)
+ {
+ ok = false;
+ if (err < 0)
+ goto wipefd_out;
+ }
}
}
- /* Okay, now deallocate the data. The effect of ftruncate on
+ /* Now deallocate the data. The effect of ftruncate on
non-regular files is unspecified, so don't worry about any
errors reported for them. */
if (flags->remove_file && ftruncate (fd, 0) != 0
&& S_ISREG (st.st_mode))
{
error (0, errno, _("%s: error truncating"), qname);
- return false;
+ ok = false;
+ goto wipefd_out;
}
+wipefd_out:
+ memset (passarray, 0, flags->n_iterations * sizeof (int));
+ free (passarray);
return ok;
}
projects / thirdparty / coreutils.git / commitdiff
