PM / Hibernate: Fix blkdev refleaks

While cruising through the swsusp code I found few blkdev reference
leaks of resume_bdev.

swsusp_read: remove blkdev_put altogether. Some fail paths do
             not do that.
swsusp_check: make sure we always put a reference on fail paths
software_resume: all fail paths between swsusp_check and swsusp_read
                 omit swsusp_close. Add it in those cases. And since
                 swsusp_read doesn't drop the reference anymore, do
                 it here unconditionally.

[rjw: Fixed a small coding style issue.]

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 04b3a83..04a9e90 100644 (file)
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -693,21 +693,22 @@ static int software_resume(void)
        /* The snapshot device should not be opened while we're running */
        if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
                error = -EBUSY;
+               swsusp_close(FMODE_READ);
                goto Unlock;
        }
 
        pm_prepare_console();
        error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
        if (error)
-               goto Finish;
+               goto close_finish;
 
        error = usermodehelper_disable();
        if (error)
-               goto Finish;
+               goto close_finish;
 
        error = create_basic_memory_bitmaps();
        if (error)
-               goto Finish;
+               goto close_finish;
 
        pr_debug("PM: Preparing processes for restore.\n");
        error = prepare_processes();
@@ -719,6 +720,7 @@ static int software_resume(void)
        pr_debug("PM: Reading hibernation image.\n");
 
        error = swsusp_read(&flags);
+       swsusp_close(FMODE_READ);
        if (!error)
                hibernation_restore(flags & SF_PLATFORM_MODE);
 
@@ -737,6 +739,9 @@ static int software_resume(void)
        mutex_unlock(&pm_mutex);
        pr_debug("PM: Resume from disk failed.\n");
        return error;
+close_finish:
+       swsusp_close(FMODE_READ);
+       goto Finish;
 }
 
 late_initcall(software_resume);

diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index b101cdc..a438862 100644 (file)
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -572,8 +572,6 @@ int swsusp_read(unsigned int *flags_p)
                error = load_image(&handle, &snapshot, header->pages - 1);
        release_swap_reader(&handle);
 
-       blkdev_put(resume_bdev, FMODE_READ);
-
        if (!error)
                pr_debug("PM: Image successfully loaded\n");
        else
@@ -596,7 +594,7 @@ int swsusp_check(void)
                error = bio_read_page(swsusp_resume_block,
                                        swsusp_header, NULL);
                if (error)
-                       return error;
+                       goto put;
 
                if (!memcmp(SWSUSP_SIG, swsusp_header->sig, 10)) {
                        memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
@@ -604,8 +602,10 @@ int swsusp_check(void)
                        error = bio_write_page(swsusp_resume_block,
                                                swsusp_header, NULL);
                } else {
-                       return -EINVAL;
+                       error = -EINVAL;
                }
+
+put:
                if (error)
                        blkdev_put(resume_bdev, FMODE_READ);
                else