On Sunday 04 August 2013 14:08:54 Dennis Groenen wrote:
> We already had the mount opts from fstab, but didn't do anything with them.
>
> Check mnt_opts and set g_flags accordingly prior to enabling the swapspace
> when
> we do_em_all().
>
> Signed-off-by: Dennis Groenen <tj.groenen at gmail.com>
> ---
> util-linux/Config.src | 5 +++--
> util-linux/swaponoff.c | 13 +++++++++++++
> 2 files changed, 16 insertions(+), 2 deletions(-)
>
> diff --git a/util-linux/Config.src b/util-linux/Config.src
> index 5a8b006..b90873d 100644
> --- a/util-linux/Config.src
> +++ b/util-linux/Config.src
> @@ -600,11 +600,12 @@ config SWAPONOFF
> option disabled.
>
> config FEATURE_SWAPON_PRI
> - bool "Support priority option -p"
> + bool "Support priority options"
> default y
> depends on SWAPONOFF
> help
> - Enable support for setting swap device priority in swapon.
> + Enable support for setting swap device priority in swapon. Also makes
> + swapon respect 'pri=n' when enabling all swaps from /etc/fstab.
>
> config SWITCH_ROOT
> bool "switch_root"
> diff --git a/util-linux/swaponoff.c b/util-linux/swaponoff.c
> index 54867ec..97f668e 100644
> --- a/util-linux/swaponoff.c
> +++ b/util-linux/swaponoff.c
> @@ -95,6 +95,19 @@ static int do_em_all(void)
> if (applet_name[5] != 'n'
> || hasmntopt(m, MNTOPT_NOAUTO) == NULL
> ) {
> +#if ENABLE_FEATURE_SWAPON_PRI /* from util-linux-ng 2.17.2 */
> + char *opt, *opts;
> +
> + g_flags = 0; /* each swap space might have
> different flags */
> + opts = strdup(m->mnt_opts);
> + for (opt = strtok(opts, ","); opt != NULL;
> + opt = strtok(NULL, ",")) {
> + if (strncmp(opt, "pri=", 4) == 0)
> + g_flags = SWAP_FLAG_PREFER |
> + ((atoi(opt+4) &
> SWAP_FLAG_PRIO_MASK) << SWAP_FLAG_PRIO_SHIFT);
> + }
> + if (ENABLE_FEATURE_CLEAN_UP) free(opts);
> +#endif
> err += swap_enable_disable(m->mnt_fsname);
> }
> }
>
Hi,
I would suggest to add a little more error checking to to parameters parsed
from fstab.
--- util-linux/swaponoff.c.original 2013-06-02 13:56:34.000000000 +0200
+++ util-linux/swaponoff.c 2013-08-04 23:42:02.497847999 +0200
@@ -82,6 +82,8 @@ static int do_em_all(void)
struct mntent *m;
FILE *f;
int err;
+ char *p;
+ int swap_prio;
f = setmntent("/etc/fstab", "r");
if (f == NULL)
@@ -95,6 +97,16 @@ static int do_em_all(void)
if (applet_name[5] != 'n'
|| hasmntopt(m, MNTOPT_NOAUTO) == NULL
) {
+ g_flags = 0; /* each swap space might have
different flags */
+ p = strstr(m->mnt_opts, "pri=");
+ if (p) {
+ /* Max allowed 32767 */
+ swap_prio = MIN(bb_strtoull(p + 4 ,
NULL, 10), 32767);
+ if (errno != ERANGE) {
+ g_flags = SWAP_FLAG_PREFER |
+ ((swap_prio &
SWAP_FLAG_PRIO_MASK) << SWAP_FLAG_PRIO_SHIFT);
+ }
+ }
err += swap_enable_disable(m->mnt_fsname);
}
}
This behaves the same as real swapon -a when:
pri is negative (skipped)
pri is bigger than 32767 (set to 32767)
the only difference is we don't handle
pri=1somechars
which we ignore and real swapon parses to
pri=1
BTW: Denys, due to my limited understanding of this complex issues i wonder why
we handle 1111xxxx as an ERANGE error in bb_strtonum.c
static unsigned long long handle_errors(unsigned long long v, char **endp)
{
char next_ch = **endp;
/* errno is already set to ERANGE by strtoXXX if value overflowed */
if (next_ch) {
/* "1234abcg" or out-of-range? */
if (isalnum(next_ch) || errno)
return ret_ERANGE();
/* good number, just suspicious terminator */
errno = EINVAL;
}
return v;
}
as the test app in the strtol man page says:
/* If we got here, strtol() successfully parsed a number */
printf("strtol() returned %ld\n", val);
if (*endptr != '\0') /* Not necessarily an error... */
printf("Further characters after number: %s\n", endptr);
So if it is not necessarily an error shouldn't we do something like:
static unsigned long long handle_errors(unsigned long long v, char **endp)
{
char next_ch = **endp;
/* errno is already set to ERANGE by strtoXXX if value overflowed */
if (next_ch) {
/* "1234abcg" or out-of-range? */
if (isalnum(next_ch) {
if (errno == ERANGE) {
return ret_ERANGE();
} else {
errno = EINVAL;
}
}
}
return v;
}
Maybe I'm just to tired now.....
Ciao,
Tito
Add priority handling to swapon -a with error checking
Signed-off-by: Tito Ragusa <farmat...@tiscali.it>
--- util-linux/swaponoff.c.original 2013-06-02 13:56:34.000000000 +0200
+++ util-linux/swaponoff.c 2013-08-04 23:42:02.497847999 +0200
@@ -82,6 +82,8 @@ static int do_em_all(void)
struct mntent *m;
FILE *f;
int err;
+ char *p;
+ int swap_prio;
f = setmntent("/etc/fstab", "r");
if (f == NULL)
@@ -95,6 +97,16 @@ static int do_em_all(void)
if (applet_name[5] != 'n'
|| hasmntopt(m, MNTOPT_NOAUTO) == NULL
) {
+ g_flags = 0; /* each swap space might have different flags */
+ p = strstr(m->mnt_opts, "pri=");
+ if (p) {
+ /* Max allowed 32767 */
+ swap_prio = MIN(bb_strtoull(p + 4 , NULL, 10), 32767);
+ if (errno != ERANGE) {
+ g_flags = SWAP_FLAG_PREFER |
+ ((swap_prio & SWAP_FLAG_PRIO_MASK) << SWAP_FLAG_PRIO_SHIFT);
+ }
+ }
err += swap_enable_disable(m->mnt_fsname);
}
}
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