New "--error-skip-block" option.

src/include/options.h

@@ -42,6 +42,7 @@ struct opts_s {           /* structure describing run-time options */
 	unsigned long long size;       /* total size of data */
 	bool no_splice;                /* flag set if never to use splice */
 	unsigned int skip_errors;      /* skip read errors counter */
+	unsigned long long error_skip_block; /* skip block size, 0 for adaptive */
 	bool stop_at_size;             /* set if we stop at "size" bytes */
 	bool sync_after_write;         /* set if we sync after every write */
 	bool direct_io;                /* set if O_DIRECT is to be used */

src/include/pv-internal.h

@@ -93,6 +93,7 @@ struct pvstate_s {
 	bool null_terminated_lines;      /* lines are null-terminated */
 	bool no_display;                 /* do nothing other than pipe data */
 	unsigned int skip_errors;        /* skip read errors counter */
+	unsigned long long error_skip_block; /* skip block size, 0 for adaptive */
 	bool stop_at_size;               /* set if we stop at "size" bytes */
 	bool sync_after_write;           /* set if we sync after every write */
 	bool direct_io;                  /* set if O_DIRECT is to be used */

src/include/pv.h

@@ -148,6 +148,7 @@ extern void pv_state_bits_set(pvstate_t, bool);
 extern void pv_state_null_terminated_lines_set(pvstate_t, bool);
 extern void pv_state_no_display_set(pvstate_t, bool);
 extern void pv_state_skip_errors_set(pvstate_t, unsigned int);
+extern void pv_state_error_skip_block_set(pvstate_t, unsigned long long);
 extern void pv_state_stop_at_size_set(pvstate_t, bool);
 extern void pv_state_sync_after_write_set(pvstate_t, bool);
 extern void pv_state_direct_io_set(pvstate_t, bool);

src/main/help.c

@@ -368,6 +368,9 @@ void display_help(void)
 		{ "-E", "--skip-errors", NULL,
 		 N_("skip read errors in input"),
 		 { 0, 0, 0, 0} },
+		{ "-Z", "--error-skip-block", N_("BYTES"),
+		 N_("skip errors in BYTES blocks at a time"),
+		 { 0, 0, 0, 0} },
 		{ "-S", "--stop-at-size", NULL,
 		 N_("stop after --size bytes have been transferred"),
 		 { 0, 0, 0, 0} },

src/main/main.c

@@ -271,6 +271,7 @@ int main(int argc, char **argv)
 	pv_state_bits_set(state, opts->bits);
 	pv_state_null_terminated_lines_set(state, opts->null_terminated_lines);
 	pv_state_skip_errors_set(state, opts->skip_errors);
+	pv_state_error_skip_block_set(state, opts->error_skip_block);
 	pv_state_stop_at_size_set(state, opts->stop_at_size);
 	pv_state_sync_after_write_set(state, opts->sync_after_write);
 	pv_state_direct_io_set(state, opts->direct_io);

src/main/options.c

@@ -169,6 +169,7 @@ opts_t opts_parse(unsigned int argc, char **argv)
 		{ "buffer-size", 1, NULL, (int) 'B' },
 		{ "no-splice", 0, NULL, (int) 'C' },
 		{ "skip-errors", 0, NULL, (int) 'E' },
+		{ "error-skip-block", 1, NULL, (int) 'Z' },
 		{ "stop-at-size", 0, NULL, (int) 'S' },
 		{ "sync", 0, NULL, (int) 'Y' },
 		{ "direct-io", 0, NULL, (int) 'K' },
@@ -185,7 +186,7 @@ opts_t opts_parse(unsigned int argc, char **argv)
 	/*@+nullassign@ */
 	int option_index = 0;
 #endif				/* HAVE_GETOPT_LONG */
-	char *short_options = "hVpteIrab8TA:fnqcWD:s:l0i:w:H:N:F:L:B:CESYKXR:P:d:m:"
+	char *short_options = "hVpteIrab8TA:fnqcWD:s:l0i:w:H:N:F:L:B:CEZ:SYKXR:P:d:m:"
 #ifdef ENABLE_DEBUGGING
 	    "!:"
 #endif
@@ -281,6 +282,8 @@ opts_t opts_parse(unsigned int argc, char **argv)
 		case 'R':
 			/*@fallthrough@ */
 		case 'm':
+			/*@fallthrough@ */
+		case 'Z':
 			if (pv_getnum_check(optarg, PV_NUMTYPE_INTEGER) != 0) {
 				/*@-mustfreefresh@ *//* see above */
 				fprintf(stderr, "%s: -%c: %s\n", opts->program_name, c, _("integer argument expected"));
@@ -461,6 +464,9 @@ opts_t opts_parse(unsigned int argc, char **argv)
 		case 'E':
 			opts->skip_errors++;
 			break;
+		case 'Z':
+			opts->error_skip_block = pv_getnum_ull(optarg);
+			break;
 		case 'S':
 			opts->stop_at_size = true;
 			break;
@@ -605,6 +611,10 @@ opts_t opts_parse(unsigned int argc, char **argv)
 		opts->bytes = true;
 	}
 
+	/* If -Z was given but not -E, pretend one -E was given too. */
+	if (opts->error_skip_block > 0 && 0 == opts->skip_errors)
+		opts->skip_errors = 1;
+
 	/*
 	 * Store remaining command-line arguments.
 	 */

src/pv/state.c

@@ -207,6 +207,11 @@ void pv_state_skip_errors_set(pvstate_t state, unsigned int val)
 	state->skip_errors = val;
 };
 
+void pv_state_error_skip_block_set(pvstate_t state, unsigned long long val)
+{
+	state->error_skip_block = val;
+}
+
 void pv_state_stop_at_size_set(pvstate_t state, bool val)
 {
 	state->stop_at_size = val;

src/pv/transfer.c

@@ -402,12 +402,21 @@ static int pv__transfer_read(pvstate_t state, int fd, int *eof_in, int *eof_out,
 		return 1;
 	}
 
-	if (state->read_errors_in_a_row < 10) {
-		amount_to_skip = state->read_errors_in_a_row < 5 ? 1 : 2;
-	} else if (state->read_errors_in_a_row < 20) {
-		amount_to_skip = 1 << (state->read_errors_in_a_row - 10);
-	} else {
-		amount_to_skip = 512;
+	/*
+	 * If a non-zero error skip block size was given, just use that,
+	 * otherwise start small and ramp up based on the number of errors
+	 * in a row.
+	 */
+	if (state->error_skip_block > 0) {
+		amount_to_skip = state->error_skip_block;
+		} else {
+		if (state->read_errors_in_a_row < 10) {
+			amount_to_skip = state->read_errors_in_a_row < 5 ? 1 : 2;
+		} else if (state->read_errors_in_a_row < 20) {
+			amount_to_skip = 1 << (state->read_errors_in_a_row - 10);
+		} else {
+			amount_to_skip = 512;
+		}
 	}
 
 	/*