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200 lines
7.6 KiB
200 lines
7.6 KiB
diff -up util-linux-2.23.2/sys-utils/swapon.8.kzak util-linux-2.23.2/sys-utils/swapon.8 |
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--- util-linux-2.23.2/sys-utils/swapon.8.kzak 2013-06-13 09:46:10.544651682 +0200 |
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+++ util-linux-2.23.2/sys-utils/swapon.8 2014-09-24 10:57:45.855230767 +0200 |
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@@ -112,15 +112,25 @@ All devices marked as ``swap'' in |
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are made available, except for those with the ``noauto'' option. |
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Devices that are already being used as swap are silently skipped. |
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.TP |
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-.B "\-d, \-\-discard" |
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-Discard freed swap pages before they are reused, if the swap |
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-device supports the discard or trim operation. This may improve |
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-performance on some Solid State Devices, but often it does not. |
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+.B "\-d, \-\-discard\fR [=\fIpolicy\fR]" |
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+Enable swap discards, if the swap backing device supports the discard or |
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+trim operation. This may improve performance on some Solid State Devices, |
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+but often it does not. The option allows one to select between two |
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+available swap discard policies: |
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+.BI \-\-discard=once |
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+to perform a single-time discard operation for the whole swap area at swapon; |
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+or |
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+.BI \-\-discard=pages |
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+to discard freed swap pages before they are reused, while swapping. |
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+If no policy is selected, the default behavior is to enable both discard types. |
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The |
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.I /etc/fstab |
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-mount option |
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-.BI discard |
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-may be also used to enable discard flag. |
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+mount options |
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+.BI discard, |
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+.BI discard=once, |
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+or |
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+.BI discard=pages |
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+may be also used to enable discard flags. |
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.TP |
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.B "\-e, \-\-ifexists" |
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Silently skip devices that do not exist. |
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diff -up util-linux-2.23.2/sys-utils/swapon.c.kzak util-linux-2.23.2/sys-utils/swapon.c |
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--- util-linux-2.23.2/sys-utils/swapon.c.kzak 2013-07-30 10:39:26.348739643 +0200 |
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+++ util-linux-2.23.2/sys-utils/swapon.c 2014-09-24 10:57:45.855230767 +0200 |
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@@ -34,9 +34,20 @@ |
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#endif |
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#ifndef SWAP_FLAG_DISCARD |
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-# define SWAP_FLAG_DISCARD 0x10000 /* discard swap cluster after use */ |
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+# define SWAP_FLAG_DISCARD 0x10000 /* enable discard for swap */ |
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#endif |
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+#ifndef SWAP_FLAG_DISCARD_ONCE |
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+# define SWAP_FLAG_DISCARD_ONCE 0x20000 /* discard swap area at swapon-time */ |
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+#endif |
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+ |
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+#ifndef SWAP_FLAG_DISCARD_PAGES |
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+# define SWAP_FLAG_DISCARD_PAGES 0x40000 /* discard page-clusters after use */ |
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+#endif |
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+ |
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+#define SWAP_FLAGS_DISCARD_VALID (SWAP_FLAG_DISCARD | SWAP_FLAG_DISCARD_ONCE | \ |
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+ SWAP_FLAG_DISCARD_PAGES) |
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+ |
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#ifndef SWAP_FLAG_PREFER |
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# define SWAP_FLAG_PREFER 0x8000 /* set if swap priority specified */ |
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#endif |
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@@ -70,7 +81,7 @@ enum { |
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static int all; |
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static int priority = -1; /* non-prioritized swap by default */ |
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-static int discard; |
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+static int discard; /* don't send swap discards by default */ |
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|
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/* If true, don't complain if the device/file doesn't exist */ |
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static int ifexists; |
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@@ -567,8 +578,22 @@ static int do_swapon(const char *orig_sp |
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<< SWAP_FLAG_PRIO_SHIFT); |
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} |
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#endif |
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- if (fl_discard) |
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- flags |= SWAP_FLAG_DISCARD; |
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+ /* |
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+ * Validate the discard flags passed and set them |
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+ * accordingly before calling sys_swapon. |
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+ */ |
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+ if (fl_discard && !(fl_discard & ~SWAP_FLAGS_DISCARD_VALID)) { |
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+ /* |
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+ * If we get here with both discard policy flags set, |
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+ * we just need to tell the kernel to enable discards |
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+ * and it will do correctly, just as we expect. |
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+ */ |
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+ if ((fl_discard & SWAP_FLAG_DISCARD_ONCE) && |
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+ (fl_discard & SWAP_FLAG_DISCARD_PAGES)) |
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+ flags |= SWAP_FLAG_DISCARD; |
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+ else |
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+ flags |= fl_discard; |
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+ } |
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status = swapon(special, flags); |
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if (status < 0) |
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@@ -608,12 +633,22 @@ static int swapon_all(void) |
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while (mnt_table_find_next_fs(tb, itr, match_swap, NULL, &fs) == 0) { |
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/* defaults */ |
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int pri = priority, dsc = discard, nofail = ifexists; |
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- char *p, *src; |
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+ char *p, *src, *dscarg; |
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if (mnt_fs_get_option(fs, "noauto", NULL, NULL) == 0) |
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continue; |
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- if (mnt_fs_get_option(fs, "discard", NULL, NULL) == 0) |
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- dsc = 1; |
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+ if (mnt_fs_get_option(fs, "discard", &dscarg, NULL) == 0) { |
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+ dsc |= SWAP_FLAG_DISCARD; |
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+ if (dscarg) { |
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+ /* only single-time discards are wanted */ |
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+ if (strcmp(dscarg, "once") == 0) |
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+ dsc |= SWAP_FLAG_DISCARD_ONCE; |
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+ |
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+ /* do discard for every released swap page */ |
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+ if (strcmp(dscarg, "pages") == 0) |
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+ dsc |= SWAP_FLAG_DISCARD_PAGES; |
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+ } |
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+ } |
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if (mnt_fs_get_option(fs, "nofail", NULL, NULL) == 0) |
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nofail = 1; |
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if (mnt_fs_get_option(fs, "pri", &p, NULL) == 0 && p) |
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@@ -643,17 +678,17 @@ static void __attribute__ ((__noreturn__ |
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fprintf(out, _(" %s [options] [<spec>]\n"), program_invocation_short_name); |
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fputs(USAGE_OPTIONS, out); |
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- fputs(_(" -a, --all enable all swaps from /etc/fstab\n" |
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- " -d, --discard discard freed pages before they are reused\n" |
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- " -e, --ifexists silently skip devices that do not exist\n" |
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- " -f, --fixpgsz reinitialize the swap space if necessary\n" |
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- " -p, --priority <prio> specify the priority of the swap device\n" |
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- " -s, --summary display summary about used swap devices\n" |
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- " --show[=<columns>] display summary in definable table\n" |
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- " --noheadings don't print headings, use with --show\n" |
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- " --raw use the raw output format, use with --show\n" |
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- " --bytes display swap size in bytes in --show output\n" |
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- " -v, --verbose verbose mode\n"), out); |
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+ fputs(_(" -a, --all enable all swaps from /etc/fstab\n" |
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+ " -d, --discard[=<policy>] enable swap discards, if supported by device\n" |
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+ " -e, --ifexists silently skip devices that do not exist\n" |
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+ " -f, --fixpgsz reinitialize the swap space if necessary\n" |
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+ " -p, --priority <prio> specify the priority of the swap device\n" |
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+ " -s, --summary display summary about used swap devices\n" |
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+ " --show[=<columns>] display summary in definable table\n" |
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+ " --noheadings don't print headings, use with --show\n" |
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+ " --raw use the raw output format, use with --show\n" |
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+ " --bytes display swap size in bytes in --show output\n" |
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+ " -v, --verbose verbose mode\n"), out); |
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fputs(USAGE_SEPARATOR, out); |
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fputs(USAGE_HELP, out); |
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@@ -669,6 +704,11 @@ static void __attribute__ ((__noreturn__ |
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" <device> name of device to be used\n" |
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" <file> name of file to be used\n"), out); |
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+ fputs(_("\nAvailable discard policy types (for --discard):\n" |
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+ " once : only single-time area discards are issued. (swapon)\n" |
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+ " pages : discard freed pages before they are reused.\n" |
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+ " * if no policy is selected both discard types are enabled. (default)\n"), out); |
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+ |
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fputs(_("\nAvailable columns (for --show):\n"), out); |
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for (i = 0; i < NCOLS; i++) |
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fprintf(out, " %4s %s\n", infos[i].name, _(infos[i].help)); |
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@@ -693,7 +733,7 @@ int main(int argc, char *argv[]) |
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static const struct option long_opts[] = { |
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{ "priority", 1, 0, 'p' }, |
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- { "discard", 0, 0, 'd' }, |
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+ { "discard", 2, 0, 'd' }, |
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{ "ifexists", 0, 0, 'e' }, |
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{ "summary", 0, 0, 's' }, |
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{ "fixpgsz", 0, 0, 'f' }, |
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@@ -716,7 +756,7 @@ int main(int argc, char *argv[]) |
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mnt_init_debug(0); |
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mntcache = mnt_new_cache(); |
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- while ((c = getopt_long(argc, argv, "ahdefp:svVL:U:", |
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+ while ((c = getopt_long(argc, argv, "ahd::efp:svVL:U:", |
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long_opts, NULL)) != -1) { |
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switch (c) { |
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case 'a': /* all */ |
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@@ -736,7 +776,18 @@ int main(int argc, char *argv[]) |
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add_uuid(optarg); |
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break; |
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case 'd': |
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- discard = 1; |
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+ discard |= SWAP_FLAG_DISCARD; |
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+ if (optarg) { |
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+ if (*optarg == '=') |
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+ optarg++; |
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+ |
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+ if (strcmp(optarg, "once") == 0) |
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+ discard |= SWAP_FLAG_DISCARD_ONCE; |
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+ else if (strcmp(optarg, "pages") == 0) |
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+ discard |= SWAP_FLAG_DISCARD_PAGES; |
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+ else |
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+ errx(EXIT_FAILURE, _("unsupported discard policy: %s"), optarg); |
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+ } |
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break; |
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case 'e': /* ifexists */ |
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ifexists = 1;
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