[PATCH 1/1] SWSUSP: fix blkdev refleaks

From: Jiri Slaby
Date: Fri Oct 02 2009 - 12:12:58 EST


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.

Signed-off-by: Jiri Slaby <jirislaby@xxxxxxxxx>
Cc: Len Brown <len.brown@xxxxxxxxx>
Cc: Pavel Machek <pavel@xxxxxx>
Cc: Rafael J. Wysocki <rjw@xxxxxxx>
---
kernel/power/hibernate.c | 11 ++++++++---
kernel/power/swap.c | 10 ++++------
2 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 04b3a83..04a9e90 100644
--- 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..cccea0b 100644
--- 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
@@ -596,16 +594,16 @@ 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);
/* Reset swap signature now */
error = bio_write_page(swsusp_resume_block,
swsusp_header, NULL);
- } else {
- return -EINVAL;
- }
+ } else
+ error = -EINVAL;
+put:
if (error)
blkdev_put(resume_bdev, FMODE_READ);
else
--
1.6.4.2

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