[klibc] [klibc:master] resume: Write resume_offset attribute
klibc-bot for Ben Hutchings
ben at decadent.org.uk
Sat Jan 19 16:24:05 PST 2019
Commit-ID: a2f9cd4abe2d5cb72e1e89089b132e866e3cea81
Gitweb: http://git.kernel.org/?p=libs/klibc/klibc.git;a=commit;h=a2f9cd4abe2d5cb72e1e89089b132e866e3cea81
Author: Ben Hutchings <ben at decadent.org.uk>
AuthorDate: Thu, 19 Jul 2018 20:09:28 +0100
Committer: Ben Hutchings <ben at decadent.org.uk>
CommitDate: Sun, 20 Jan 2019 00:22:24 +0000
[klibc] resume: Write resume_offset attribute
Support for a device offset as part of the string written to
/sys/power/resume never got into a mainline kernel.
However, since Linux 4.17 there is a separate resume_offset attribute
that we can use to set the offset before attempting to resume.
Change resume() to write the resume_offset attribute instead.
Signed-off-by: Ben Hutchings <ben at decadent.org.uk>
---
usr/kinit/resume/resumelib.c | 42 +++++++++++++++++++++++++++++++-----------
1 file changed, 31 insertions(+), 11 deletions(-)
diff --git a/usr/kinit/resume/resumelib.c b/usr/kinit/resume/resumelib.c
index e557b05..03e596a 100644
--- a/usr/kinit/resume/resumelib.c
+++ b/usr/kinit/resume/resumelib.c
@@ -44,8 +44,8 @@ int do_resume(int argc, char *argv[])
int resume(const char *resume_file, unsigned long long resume_offset)
{
dev_t resume_device;
- int powerfd = -1;
- char device_string[64];
+ int attr_fd = -1;
+ char attr_value[64];
int len;
resume_device = name_to_dev_t(resume_file);
@@ -55,30 +55,50 @@ int resume(const char *resume_file, unsigned long long resume_offset)
goto failure;
}
- if ((powerfd = open("/sys/power/resume", O_WRONLY)) < 0)
- goto fail_r;
+ if ((attr_fd = open("/sys/power/resume_offset", O_WRONLY)) < 0)
+ goto fail_offset;
- len = snprintf(device_string, sizeof device_string,
- "%u:%u:%llu",
- major(resume_device), minor(resume_device),
+ len = snprintf(attr_value, sizeof attr_value,
+ "%llu",
resume_offset);
/* This should never happen */
- if (len >= sizeof device_string)
+ if (len >= sizeof attr_value)
+ goto fail_offset;
+
+ if (write(attr_fd, attr_value, len) != len)
+ goto fail_offset;
+
+ close(attr_fd);
+
+ if ((attr_fd = open("/sys/power/resume", O_WRONLY)) < 0)
+ goto fail_r;
+
+ len = snprintf(attr_value, sizeof attr_value,
+ "%u:%u",
+ major(resume_device), minor(resume_device));
+
+ /* This should never happen */
+ if (len >= sizeof attr_value)
goto fail_r;
dprintf("kinit: trying to resume from %s\n", resume_file);
- if (write(powerfd, device_string, len) != len)
+ if (write(attr_fd, attr_value, len) != len)
goto fail_r;
/* Okay, what are we still doing alive... */
failure:
- if (powerfd >= 0)
- close(powerfd);
+ if (attr_fd >= 0)
+ close(attr_fd);
dprintf("kinit: No resume image, doing normal boot...\n");
return -1;
+fail_offset:
+ fprintf(stderr, "Cannot write /sys/power/resume_offset "
+ "(no software suspend kernel support, or old kernel version?)\n");
+ goto failure;
+
fail_r:
fprintf(stderr, "Cannot write /sys/power/resume "
"(no software suspend kernel support?)\n");
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