From: Shaohua Li <[EMAIL PROTECTED]> It is trying to protect swsusp_resume_device and software_resume() from two users banging it from userspace at the same time.
Signed-off-by: Shaohua Li <[EMAIL PROTECTED]> Signed-off-by: Pavel Machek <[EMAIL PROTECTED]> --- commit c1d6e115ea6f797563fe6873de25892cb16a309e tree 53b5eead95da859baf820be52a62b2ddab007c29 parent 86fa9d8a44c633603139b427c160ed1cdd41c6ce author <[EMAIL PROTECTED](none)> Tue, 02 Aug 2005 13:19:38 +0200 committer <[EMAIL PROTECTED](none)> Tue, 02 Aug 2005 13:19:38 +0200 kernel/power/disk.c | 10 +++++++++- 1 files changed, 9 insertions(+), 1 deletions(-) diff --git a/kernel/power/disk.c b/kernel/power/disk.c --- a/kernel/power/disk.c +++ b/kernel/power/disk.c @@ -233,9 +233,12 @@ static int software_resume(void) { int error; + down(&pm_sem); if (!swsusp_resume_device) { - if (!strlen(resume_file)) + if (!strlen(resume_file)) { + up(&pm_sem); return -ENOENT; + } swsusp_resume_device = name_to_dev_t(resume_file); pr_debug("swsusp: Resume From Partition %s\n", resume_file); } else { @@ -248,6 +251,7 @@ static int software_resume(void) * FIXME: If noresume is specified, we need to find the partition * and reset it back to normal swap space. */ + up(&pm_sem); return 0; } @@ -284,6 +288,8 @@ static int software_resume(void) Cleanup: unprepare_processes(); Done: + /* For success case, the suspend path will release the lock */ + up(&pm_sem); pr_debug("PM: Resume from disk failed.\n"); return 0; } @@ -390,7 +396,9 @@ static ssize_t resume_store(struct subsy if (sscanf(buf, "%u:%u", &maj, &min) == 2) { res = MKDEV(maj,min); if (maj == MAJOR(res) && min == MINOR(res)) { + down(&pm_sem); swsusp_resume_device = res; + up(&pm_sem); printk("Attempting manual resume\n"); noresume = 0; software_resume(); -- teflon -- maybe it is a trademark, but it should not be. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/