@@ -69,7 +69,7 @@ resume [-BdqrR] <path>|<device>
.. _man-scrub-start:
-start [-BdrRf] <path>|<device>
+start [options] <path>|<device>
Start a scrub on all devices of the mounted filesystem identified by
*path* or on a single *device*. If a scrub is already running, the new
one will not start. A device of an unmounted filesystem cannot be
@@ -96,6 +96,17 @@ start [-BdrRf] <path>|<device>
can avoid writes from scrub.
-R
raw print mode, print full data instead of summary
+ --limit <limit>
+ set the scrub throughput limit for each device.
+
+ If the scrub is for the whole fs, it's the same as
+ :command:`btrfs scrub limit -a -l <value>`.
+ If the scrub is for a single device, it's the same as
+ :command:`btrfs scrub limit -d <devid> -l <value>`.
+
+ The value is bytes per second, and accepts the usual KMGT prefixes.
+ After the scrub is finished, the throughput limit will be reset to
+ the old value of each device.
-f
force starting new scrub even if a scrub is already running,
this can useful when scrub status file is damaged and reports a
@@ -97,6 +97,7 @@ struct scrub_progress {
pthread_mutex_t progress_mutex;
int ioprio_class;
int ioprio_classdata;
+ u64 old_limit;
u64 limit;
};
@@ -1230,7 +1231,6 @@ static int scrub_start(const struct cmd_struct *cmd, int argc, char **argv,
int fdres = -1;
int ret;
pid_t pid;
- int c;
int i;
int err = 0;
int e_uncorrectable = 0;
@@ -1265,11 +1265,22 @@ static int scrub_start(const struct cmd_struct *cmd, int argc, char **argv,
struct scrub_progress_cycle spc;
pthread_mutex_t spc_write_mutex = PTHREAD_MUTEX_INITIALIZER;
void *terr;
+ u64 throughput_limit = 0;
u64 devid;
bool force = false;
bool nothing_to_resume = false;
- while ((c = getopt(argc, argv, "BdqrRc:n:f")) != -1) {
+ while (1) {
+ int c;
+ enum { GETOPT_VAL_LIMIT = GETOPT_VAL_FIRST };
+ static const struct option long_options[] = {
+ {"limit", required_argument, NULL, GETOPT_VAL_LIMIT},
+ { NULL, 0, NULL, 0 }
+ };
+
+ c = getopt_long(argc, argv, "BdqrRc:n:f", long_options, NULL);
+ if (c < 0)
+ break;
switch (c) {
case 'B':
do_background = false;
@@ -1297,6 +1308,9 @@ static int scrub_start(const struct cmd_struct *cmd, int argc, char **argv,
case 'f':
force = true;
break;
+ case GETOPT_VAL_LIMIT:
+ throughput_limit = arg_strtou64_with_suffix(optarg);
+ break;
default:
usage_unknown_option(cmd, argv);
}
@@ -1389,6 +1403,13 @@ static int scrub_start(const struct cmd_struct *cmd, int argc, char **argv,
for (i = 0; i < fi_args.num_devices; ++i) {
devid = di_args[i].devid;
+ sp[i].old_limit = read_scrub_device_limit(fdmnt, devid);
+ ret = write_scrub_device_limit(fdmnt, devid, throughput_limit);
+ if (ret < 0) {
+ errno = -ret;
+ warning("failed to set scrub throughput limit on devid %llu: %m",
+ devid);
+ }
ret = pthread_mutex_init(&sp[i].progress_mutex, NULL);
if (ret) {
errno = ret;
@@ -1568,6 +1589,14 @@ static int scrub_start(const struct cmd_struct *cmd, int argc, char **argv,
err = 0;
for (i = 0; i < fi_args.num_devices; ++i) {
+ /* Revert to the older scrub limit. */
+ ret = write_scrub_device_limit(fdmnt, di_args[i].devid, sp[i].old_limit);
+ if (ret < 0) {
+ errno = -ret;
+ warning("failed to reset scrub throughput limit on devid %llu: %m",
+ di_args[i].devid);
+ }
+
if (sp[i].skip)
continue;
devid = di_args[i].devid;
@@ -1713,6 +1742,7 @@ static const char * const cmd_scrub_start_usage[] = {
OPTLINE("-c", "set ioprio class (see ionice(1) manpage)"),
OPTLINE("-n", "set ioprio classdata (see ionice(1) manpage)"),
OPTLINE("-f", "force starting new scrub even if a scrub is already running this is useful when scrub stats record file is damaged"),
+ OPTLINE("--limit", "set the throughput limit for each device"),
OPTLINE("-q", "deprecated, alias for global -q option"),
HELPINFO_INSERT_GLOBALS,
HELPINFO_INSERT_QUIET,
Add a new option `--limit <throughput_limit>` to `btrfs scrub start`. This has some extra behavior differences compared to `btrfs scrub limit`: - Only set the value for the involved scrub device(s) If it's a full fs scrub, it will be the same as `btrfs scrub limit -a -l <value>`. If it's a single device, it will bt the same as `btrfs scrub limit -d <devid> -l <value>`. - Automatically revert to the old limit after scrub is finished - It only needs one single command line to set the limit Issue: #943 Signed-off-by: Qu Wenruo <wqu@suse.com> --- Changelog: RFC->v1: - Use longer option '--limit' instead - Update the docs and helper strings - Save and revert to the older limit values after scrub is finished --- Documentation/btrfs-scrub.rst | 13 ++++++++++++- cmds/scrub.c | 34 ++++++++++++++++++++++++++++++++-- 2 files changed, 44 insertions(+), 3 deletions(-) -- 2.48.1