From: Mikulas Patocka <mpato...@redhat.com>
[ Upstream commit 6e11952a6abc4641dc8ae63f01b318b31b44e8db ]
If dm_register_path_selector, don't print the "version X loaded" message.
Signed-off-by: Mikulas Patocka <mpato...@redhat.com>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
LLM Generated explanations, may be completely bogus:
**Backport Status: YES**
This commit is a clear candidate for backporting to stable kernel trees.
Here's my extensive analysis:
## Bug Analysis
The commit fixes a logic error in the error handling of four device-
mapper path selector modules. Looking at the code changes:
1. **Original buggy behavior**: When `dm_register_path_selector()` fails
(returns r < 0), the code would:
- Print "register failed" error message
- **Continue to print "version X loaded" message**
- Return the error code
2. **Fixed behavior**: When registration fails:
- Print "register failed" error message
- **Return immediately with the error code**
- Skip the misleading "loaded" message
## Why This Should Be Backported
1. **Clear Bug Fix**: This is a straightforward bug fix that corrects
misleading log messages. When module registration fails, it
incorrectly reports success with "version X loaded".
2. **Small and Contained**: The fix is minimal - just adding an early
return statement in four similar init functions:
- `dm_hst_init()` in dm-ps-historical-service-time.c
- `dm_ql_init()` in dm-ps-queue-length.c
- `dm_rr_init()` in dm-ps-round-robin.c
- `dm_st_init()` in dm-ps-service-time.c
3. **No Side Effects**: The change only affects error path behavior and
logging. It doesn't introduce new functionality or change any
successful operation paths.
4. **User-Visible Issue**: This fixes a user-visible problem where
system logs would incorrectly indicate a module loaded successfully
when it actually failed.
5. **Consistent Pattern**: All four files have the identical bug and
identical fix, showing this is a systematic issue that should be
addressed.
6. **Low Risk**: The change is trivial - adding an early return on
error. There's virtually no risk of regression since:
- It only changes behavior when registration already failed
- The function already returns the error code at the end
- This just makes it return earlier without printing the misleading
message
7. **Affects Core Subsystem**: Device-mapper is a critical storage
subsystem, and accurate error reporting is important for system
administrators debugging storage issues.
The commit perfectly fits stable kernel criteria: it's a small, obvious
fix for a real bug that affects users (through misleading log messages),
with minimal risk of introducing new problems.
drivers/md/dm-ps-historical-service-time.c | 4 +++-
drivers/md/dm-ps-queue-length.c | 4 +++-
drivers/md/dm-ps-round-robin.c | 4 +++-
drivers/md/dm-ps-service-time.c | 4 +++-
4 files changed, 12 insertions(+), 4 deletions(-)
diff --git a/drivers/md/dm-ps-historical-service-time.c
b/drivers/md/dm-ps-historical-service-time.c
index b49e10d76d03..2c8626a83de4 100644
--- a/drivers/md/dm-ps-historical-service-time.c
+++ b/drivers/md/dm-ps-historical-service-time.c
@@ -541,8 +541,10 @@ static int __init dm_hst_init(void)
{
int r = dm_register_path_selector(&hst_ps);
- if (r < 0)
+ if (r < 0) {
DMERR("register failed %d", r);
+ return r;
+ }
DMINFO("version " HST_VERSION " loaded");
diff --git a/drivers/md/dm-ps-queue-length.c b/drivers/md/dm-ps-queue-length.c
index e305f05ad1e5..eb543e6431e0 100644
--- a/drivers/md/dm-ps-queue-length.c
+++ b/drivers/md/dm-ps-queue-length.c
@@ -260,8 +260,10 @@ static int __init dm_ql_init(void)
{
int r = dm_register_path_selector(&ql_ps);
- if (r < 0)
+ if (r < 0) {
DMERR("register failed %d", r);
+ return r;
+ }
DMINFO("version " QL_VERSION " loaded");
diff --git a/drivers/md/dm-ps-round-robin.c b/drivers/md/dm-ps-round-robin.c
index d1745b123dc1..66a15ac0c22c 100644
--- a/drivers/md/dm-ps-round-robin.c
+++ b/drivers/md/dm-ps-round-robin.c
@@ -220,8 +220,10 @@ static int __init dm_rr_init(void)
{
int r = dm_register_path_selector(&rr_ps);
- if (r < 0)
+ if (r < 0) {
DMERR("register failed %d", r);
+ return r;
+ }
DMINFO("version " RR_VERSION " loaded");
diff --git a/drivers/md/dm-ps-service-time.c b/drivers/md/dm-ps-service-time.c
index 969d31c40272..f8c43aecdb27 100644
--- a/drivers/md/dm-ps-service-time.c
+++ b/drivers/md/dm-ps-service-time.c
@@ -341,8 +341,10 @@ static int __init dm_st_init(void)
{
int r = dm_register_path_selector(&st_ps);
- if (r < 0)
+ if (r < 0) {
DMERR("register failed %d", r);
+ return r;
+ }
DMINFO("version " ST_VERSION " loaded");
--
2.39.5
