Add bandwidth limit feature --bw-limit

HISTORY

@@ -1,6 +1,10 @@
 SnapRAID HISTORY
 ================
 
+12.5 2025/XX
+============
+ * Add a bandwidth limit option --bw-limit [Allan Clark]
+
 12.4 2025/01
 ============
  * Avoid a warning about function pointer conversion. No functional changes.

Makefile.am

@@ -25,6 +25,7 @@ snapraid_SOURCES = \
 	tommyds/tommy.c \
 	cmdline/snapraid.c \
 	cmdline/io.c \
+	cmdline/bw.c \
 	cmdline/util.c \
 	cmdline/stream.c \
 	cmdline/support.c \
@@ -78,6 +79,7 @@ noinst_HEADERS = \
 	cmdline/portable.h \
 	cmdline/snapraid.h \
 	cmdline/io.h \
+	cmdline/bw.h \
 	cmdline/util.h \
 	cmdline/stream.h \
 	cmdline/support.h \
@@ -237,7 +239,7 @@ if HAVE_THREAD_CHECKER
 	mv bench/disk3/a/9* bench/disk6/a
 	$(TESTENV) ./mktest$(EXEEXT) change 2 500 bench/disk2/b/* bench/disk3/b/*
 # Sync again
-	$(TESTENV) ./snapraid$(EXEEXT) $(CHECKFLAGS) -c $(CONF) sync
+	$(TESTENV) ./snapraid$(EXEEXT) $(CHECKFLAGS) -c $(CONF) sync --bw-limit 1M
 # Other commands that uses threads
 	$(TESTENV) ./snapraid$(EXEEXT) $(CHECKFLAGS) -c $(CONF) test-rewrite
 	$(TESTENV) ./snapraid$(EXEEXT) $(CHECKFLAGS) -c $(CONF) scrub -p full
@@ -288,7 +290,7 @@ endif
 if HAVE_POSIX
 	$(TESTENV) ./snapraid$(EXEEXT) $(CHECKFLAGS) -c $(PAR1) pool
 endif
-	$(TESTENV) ./snapraid$(EXEEXT) $(CHECKFLAGS) -c $(CONF) check
+	$(TESTENV) ./snapraid$(EXEEXT) $(CHECKFLAGS) -c $(CONF) check --bw-limit 1M
 	$(TESTENV) ./snapraid$(EXEEXT) $(CHECKFLAGS) -c $(CONF) -a check
 #### CONTROLLED ####
 	$(MSG) Filesystem allocation test

cmdline/bw.c

@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2016 Andrea Mazzoleni
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "portable.h"
+
+#include "bw.h"
+
+void bw_init(struct snapraid_bw* bw, uint64_t limit)
+{
+	bw->limit = limit;
+	bw->total = 0;
+	bw->start = tick_ms();
+}
+
+void bw_limit(struct snapraid_bw* bw, uint64_t bytes)
+{
+	if (!bw || bw->limit == 0)
+		return;
+
+	uint64_t elapsed = tick_ms() - bw->start;
+	uint64_t done;
+	uint64_t eta;
+
+	done = __atomic_add_fetch(&bw->total, bytes, __ATOMIC_SEQ_CST);
+
+	eta = done * 1000 / bw->limit;
+
+	if (eta > elapsed) {
+		eta -= elapsed;
+		usleep(eta * 1000);
+	}
+}

cmdline/bw.h

@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2016 Andrea Mazzoleni
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __BW_H
+#define __BW_H
+
+#include "state.h"
+#include "support.h"
+
+/**
+ * Bandwidth limiting
+ */
+struct snapraid_bw {
+	uint64_t limit; /**< Bandwidth limit in bytes per second */
+	uint64_t total; /**< Remaining bytes allowed in current second */
+	uint64_t start; /**< Time when to reset the bandwidth counter */
+};
+
+/**
+ * Initialize the bandwidth limit
+ */
+void bw_init(struct snapraid_bw* bw, uint64_t limit);
+
+/**
+ * Limit IO bandwidth to stay within the configured limit.
+ * If no limit is set, returns immediately.
+ * Otherwise sleeps as needed to maintain the rate limit.
+ */
+void bw_limit(struct snapraid_bw* bw, uint64_t bytes);
+
+#endif

cmdline/check.c

@@ -888,9 +888,20 @@ static int state_check_process(struct snapraid_state* state, int fix, struct sna
 	char esc_buffer[ESC_MAX];
 	char esc_buffer_alt[ESC_MAX];
 	bit_vect_t* block_enabled;
+	struct snapraid_bw bw;
 
 	handle = handle_mapping(state, &diskmax);
 
+	/* initialize the bandwith context */
+	bw_init(&bw, state->opt.bwlimit);
+
+	/* share the bandwidth context with all handles */
+	for (j = 0; j < diskmax; ++j)
+		handle[j].bw = &bw;
+	for (j = 0; j < state->level; ++j)
+		if (parity[j])
+			parity[j]->bw = &bw;
+
 	/* we need 1 * data + 2 * parity + 1 * zero */
 	buffermax = diskmax + 2 * state->level + 1;
 
@@ -2085,4 +2096,3 @@ int state_check(struct snapraid_state* state, int fix, block_off_t blockstart, b
 		return -1;
 	return 0;
 }
-

cmdline/fnmatch.h

@@ -47,6 +47,8 @@ extern "C" {
 #undef	FNM_PATHNAME
 #undef	FNM_NOESCAPE
 #undef	FNM_PERIOD
+#undef	FNM_LEADING_DIR
+#undef	FNM_CASEFOLD
 
 /* Bits set in the FLAGS argument to `fnmatch'.  */
 #define	FNM_PATHNAME	(1 << 0) /* No wildcard can ever match `/'.  */

cmdline/handle.c

@@ -261,6 +261,8 @@ int handle_read(struct snapraid_handle* handle, block_off_t file_pos, unsigned c
 
 	count = 0;
 	do {
+		bw_limit(handle->bw, block_size - count);
+
 		/* read the full block to support O_DIRECT */
 		read_ret = pread(handle->f, block_buffer + count, block_size - count, offset + count);
 		if (read_ret < 0) {
@@ -372,6 +374,7 @@ struct snapraid_handle* handle_mapping(struct snapraid_state* state, unsigned* h
 		handle[j].file = 0;
 		handle[j].f = -1;
 		handle[j].valid_size = 0;
+		handle[j].bw = 0;
 	}
 
 	/* set the vector */

cmdline/handle.h

@@ -20,6 +20,7 @@
 
 #include "state.h"
 #include "support.h"
+#include "bw.h"
 
 /****************************************************************************/
 /* handle */
@@ -33,6 +34,7 @@ struct snapraid_handle {
 	struct advise_struct advise; /**< Advise information. */
 	data_off_t valid_size; /**< Size of the valid data. */
 	int created; /**< If the file was created, otherwise it was already existing. */
+	struct snapraid_bw* bw; /**< Context for bandwidth limiting. */
 };
 
 /**

cmdline/io.c

@@ -877,6 +877,15 @@ void io_init(struct snapraid_io* io, struct snapraid_state* state,
 
 	io->state = state;
 
+	/* initialize bandwidth limiting */
+	bw_init(&io->bw, state->opt.bwlimit);
+
+	/* set IO context in handles */
+	for (i = 0; i < handle_max; ++i)
+		handle_map[i].bw = &io->bw;
+	for (i = 0; i < parity_handle_max; ++i)
+		parity_handle_map[i].bw = &io->bw;
+
 #if HAVE_THREAD
 	if (io_cache == 0) {
 		/* default is 16 MiB of cache */

cmdline/io.h

@@ -288,6 +288,11 @@ struct snapraid_io {
 	 * Counts the error happening in the writers.
 	 */
 	int writer_error[IO_WRITER_ERROR_MAX];
+
+	/**
+	 * Bandwidth
+	 */
+	struct snapraid_bw bw;
 };
 
 /**

cmdline/mingw.c

@@ -1554,6 +1554,11 @@ void windows_sleep(unsigned seconds)
 	Sleep(seconds * 1000);
 }
 
+void windows_usleep(uint64_t useconds)
+{
+	Sleep(useconds / 1000);
+}
+
 int windows_link(const char* existing, const char* file)
 {
 	wchar_t conv_buf_file[CONV_MAX];

cmdline/mingw.h

@@ -99,6 +99,8 @@
 #define stat_desc windows_stat_desc
 #undef sleep
 #define sleep windows_sleep
+#undef usleep
+#define usleep windows_usleep
 /* 4==DIR, 5,6,7=free, 8==REG */
 #define S_IFLNK 0x5000 /* Symbolic link to file */
 #define S_ISLNK(m) (((m) & _S_IFMT) == S_IFLNK)
@@ -331,6 +333,11 @@ const char* windows_stat_desc(struct stat* st);
  */
 void windows_sleep(unsigned seconds);
 
+/**
+ * List usleep().
+ */
+void windows_usleep(uint64_t useconds);
+
 /**
  * Like readlink().
  */

cmdline/parity.c

@@ -864,6 +864,8 @@ int parity_write(struct snapraid_parity_handle* handle, block_off_t pos, unsigne
 	if (split->valid_size < offset + block_size)
 		split->valid_size = offset + block_size;
 
+	bw_limit(handle->bw, block_size);
+
 	write_ret = pwrite(split->f, block_buffer, block_size, offset);
 	if (write_ret != (ssize_t)block_size) { /* conversion is safe because block_size is always small */
 		/* LCOV_EXCL_START */
@@ -915,6 +917,8 @@ int parity_read(struct snapraid_parity_handle* handle, block_off_t pos, unsigned
 
 	count = 0;
 	do {
+		bw_limit(handle->bw, block_size - count);
+
 		read_ret = pread(split->f, block_buffer + count, block_size - count, offset + count);
 		if (read_ret < 0) {
 			/* LCOV_EXCL_START */

cmdline/parity.h

@@ -19,6 +19,7 @@
 #define __PARITY_H
 
 #include "support.h"
+#include "bw.h"
 
 /****************************************************************************/
 /* parity */
@@ -57,6 +58,7 @@ struct snapraid_parity_handle {
 	struct snapraid_split_handle split_map[SPLIT_MAX];
 	unsigned split_mac; /**< Number of parity splits. */
 	unsigned level; /**< Level of the parity. */
+	struct snapraid_bw* bw; /**< Context for bandwidth limiting. */
 };
 
 /**

cmdline/snapraid.c

@@ -74,6 +74,7 @@ void usage(void)
 	printf("  " SWITCH_GETOPT_LONG("-N, --force-nocopy    ", "-N") "  Force commands disabling the copy detection\n");
 	printf("  " SWITCH_GETOPT_LONG("-F, --force-full      ", "-F") "  Force a full parity computation in sync\n");
 	printf("  " SWITCH_GETOPT_LONG("-R, --force-realloc   ", "-R") "  Force a full parity reallocation in sync\n");
+	printf("  " SWITCH_GETOPT_LONG("-w, --bw-limit RATE   ", "-w") "  Limit IO bandwidth (M|G)\n");
 	printf("  " SWITCH_GETOPT_LONG("-v, --verbose         ", "-v") "  Verbose\n");
 }
 
@@ -333,6 +334,7 @@ struct option long_options[] = {
 	{ "force-nocopy", 0, 0, 'N' },
 	{ "force-full", 0, 0, 'F' },
 	{ "force-realloc", 0, 0, 'R' },
+	{ "bw-limit", 1, 0, 'w' },
 	{ "audit-only", 0, 0, 'a' },
 	{ "pre-hash", 0, 0, 'h' },
 	{ "speed-test", 0, 0, 'T' }, /* undocumented speed test command */
@@ -484,7 +486,7 @@ struct option long_options[] = {
 };
 #endif
 
-#define OPTIONS "c:f:d:mebp:o:S:B:L:i:l:ZEUDNFRahTC:vqHVG"
+#define OPTIONS "c:f:d:mebp:o:S:B:L:i:l:ZEUDNFRahTC:vqHVGw:"
 
 volatile int global_interrupt = 0;
 
@@ -673,6 +675,37 @@ int main(int argc, char* argv[])
 				/* LCOV_EXCL_STOP */
 			}
 			break;
+		case 'w' : /* --bw-limit */
+			if (optarg == 0) {
+				/* LCOV_EXCL_START */
+				log_fatal("Missing bandwidth limit\n");
+				exit(EXIT_FAILURE);
+				/* LCOV_EXCL_STOP */
+			}
+
+			/* Parse the number part */
+			opt.bwlimit = strtoul(optarg, &e, 10);
+			if (!e || e == optarg) {
+				/* LCOV_EXCL_START */
+				log_fatal("Invalid bandwidth limit '%s'\n", optarg);
+				exit(EXIT_FAILURE);
+				/* LCOV_EXCL_STOP */
+			}
+
+			/* Handle suffixes */
+			if ((e[0] == 'k' || e[0] == 'K') && e[1] == 0) {
+				opt.bwlimit *= 1000;
+			} else if ((e[0] == 'm' || e[0] == 'M') && e[1] == 0) {
+				opt.bwlimit *= 1000 * 1000;
+			} else if ((e[0] == 'g' || e[0] == 'G') && e[1] == 0) {
+				opt.bwlimit *= 1000 * 1000 * 1000;
+			} else if (e[0] != '\0') {
+				/* LCOV_EXCL_START */
+				log_fatal("Invalid bandwidth limit suffix '%s'\n", e);
+				exit(EXIT_FAILURE);
+				/* LCOV_EXCL_STOP */
+			}
+			break;
 		case 'S' :
 			blockstart = strtoul(optarg, &e, 0);
 			if (!e || *e) {
@@ -1543,4 +1576,3 @@ int main(int argc, char* argv[])
 
 	return EXIT_SUCCESS;
 }
-

cmdline/state.h

@@ -120,6 +120,7 @@ struct snapraid_option {
 	int force_stats; /**< Force stats print during process. */
 	uint64_t parity_limit_size; /**< Test limit for parity files. */
 	int skip_multi_scan; /**< Don't use threads in scan. */
+	uint64_t bwlimit; /**< Bandwidth limit in bytes per second. */
 };
 
 struct snapraid_state {

snapraid.1

@@ -25,6 +25,10 @@ snapraid [\-c, \-\-conf CONFIG]
 	[\-o, \-\-older\-than DAYS] [\-l, \-\-log FILE]
 .PD 0
 .PP
+.PD
+	[\-w, \-\-bw\-limit RATE]
+.PD 0
+.PP
 .PD
 	[\-Z, \-\-force\-zero] [\-E, \-\-force\-empty]
 .PD 0
@@ -1092,6 +1096,11 @@ The files are read also in sub\-directories and they are
 identified regardless of their name.
 This option can be used only with \[dq]check\[dq] and \[dq]fix\[dq].
 .TP
+.B \-w, \-\-bw\-limit RATE
+Applies a global bandwidth limit for all disks. The RATE is
+the number of bytes per second. You can specify a multiplier
+as K, M, or G (e.g., \-\-bw\-limit 1G).
+.TP
 .B \-Z, \-\-force\-zero
 Forces the insecure operation of syncing a file with zero
 size that before was not.

snapraid.d

@@ -8,6 +8,7 @@ Synopsis
 	:	[-a, --audit-only] [-h, --pre-hash] [-i, --import DIR]
 	:	[-p, --plan PERC|bad|new|full]
 	:	[-o, --older-than DAYS] [-l, --log FILE]
+	:	[-w, --bw-limit RATE]
 	:	[-Z, --force-zero] [-E, --force-empty]
 	:	[-U, --force-uuid] [-D, --force-device]
 	:	[-N, --force-nocopy] [-F, --force-full]
@@ -788,6 +789,11 @@ Options
 		identified regardless of their name.
 		This option can be used only with "check" and "fix".
 
+	-w, --bw-limit RATE
+		Applies a global bandwidth limit for all disks. The RATE is
+		the number of bytes per second. You can specify a multiplier
+		as K, M, or G (e.g., --bw-limit 1G).
+
 	-Z, --force-zero
 		Forces the insecure operation of syncing a file with zero
 		size that before was not.

snapraid.txt

@@ -12,6 +12,7 @@ snapraid [-c, --conf CONFIG]
 	[-a, --audit-only] [-h, --pre-hash] [-i, --import DIR]
 	[-p, --plan PERC|bad|new|full]
 	[-o, --older-than DAYS] [-l, --log FILE]
+	[-w, --bw-limit RATE]
 	[-Z, --force-zero] [-E, --force-empty]
 	[-U, --force-uuid] [-D, --force-device]
 	[-N, --force-nocopy] [-F, --force-full]
@@ -845,6 +846,11 @@ SnapRAID provides the following options:
         identified regardless of their name.
         This option can be used only with "check" and "fix".
 
+    -w, --bw-limit RATE
+        Applies a global bandwidth limit for all disks. The RATE is
+        the number of bytes per second. You can specify a multiplier
+        as K, M, or G (e.g., --bw-limit 1G).
+
     -Z, --force-zero
         Forces the insecure operation of syncing a file with zero
         size that before was not.