2021-05-29 10:34:50

by Rikard Falkeborn

Subject: [PATCH] md: Constify attribute_group structs

The attribute_group structs are never modified, they're only passed to
sysfs_create_group() and sysfs_remove_group(). Make them const to allow
the compiler to put them in read-only memory.

Signed-off-by: Rikard Falkeborn <[email protected]>
---
drivers/md/md-bitmap.c | 2 +-
drivers/md/md.c | 6 +++---
drivers/md/md.h | 4 ++--
drivers/md/raid5.c | 2 +-
4 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c
index ea3130e11680..e29c6298ef5c 100644
--- a/drivers/md/md-bitmap.c
+++ b/drivers/md/md-bitmap.c
@@ -2616,7 +2616,7 @@ static struct attribute *md_bitmap_attrs[] = {
&max_backlog_used.attr,
NULL
};
-struct attribute_group md_bitmap_group = {
+const struct attribute_group md_bitmap_group = {
.name = "bitmap",
.attrs = md_bitmap_attrs,
};
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 49f897fbb89b..0e40bb5618a1 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -824,7 +824,7 @@ static struct mddev *mddev_alloc(dev_t unit)
return ERR_PTR(error);
}

-static struct attribute_group md_redundancy_group;
+static const struct attribute_group md_redundancy_group;

void mddev_unlock(struct mddev *mddev)
{
@@ -841,7 +841,7 @@ void mddev_unlock(struct mddev *mddev)
* test it under the same mutex to ensure its correct value
* is seen.
*/
- struct attribute_group *to_remove = mddev->to_remove;
+ const struct attribute_group *to_remove = mddev->to_remove;
mddev->to_remove = NULL;
mddev->sysfs_active = 1;
mutex_unlock(&mddev->reconfig_mutex);
@@ -5538,7 +5538,7 @@ static struct attribute *md_redundancy_attrs[] = {
&md_degraded.attr,
NULL,
};
-static struct attribute_group md_redundancy_group = {
+static const struct attribute_group md_redundancy_group = {
.name = NULL,
.attrs = md_redundancy_attrs,
};
diff --git a/drivers/md/md.h b/drivers/md/md.h
index fb7eab58cfd5..31e743e2ecae 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -481,7 +481,7 @@ struct mddev {
atomic_t max_corr_read_errors; /* max read retries */
struct list_head all_mddevs;

- struct attribute_group *to_remove;
+ const struct attribute_group *to_remove;

struct bio_set bio_set;
struct bio_set sync_set; /* for sync operations like
@@ -613,7 +613,7 @@ struct md_sysfs_entry {
ssize_t (*show)(struct mddev *, char *);
ssize_t (*store)(struct mddev *, const char *, size_t);
};
-extern struct attribute_group md_bitmap_group;
+extern const struct attribute_group md_bitmap_group;

static inline struct kernfs_node *sysfs_get_dirent_safe(struct kernfs_node *sd, char *name)
{
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 841e1c1aa5e6..b0a3050aa0a4 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -6930,7 +6930,7 @@ static struct attribute *raid5_attrs[] = {
&ppl_write_hint.attr,
NULL,
};
-static struct attribute_group raid5_attrs_group = {
+static const struct attribute_group raid5_attrs_group = {
.name = NULL,
.attrs = raid5_attrs,
};
--
2.31.1

2021-06-01 04:27:24

by Song Liu

Subject: Re: [PATCH] md: Constify attribute_group structs

On Sat, May 29, 2021 at 3:30 AM Rikard Falkeborn
<[email protected]> wrote:
>
> The attribute_group structs are never modified, they're only passed to
> sysfs_create_group() and sysfs_remove_group(). Make them const to allow
> the compiler to put them in read-only memory.
>
> Signed-off-by: Rikard Falkeborn <[email protected]>

Applied to md-next. Thanks!
Song