[PATCH] vfs: change iterate_supers callback to take an int arg instead of a void *

Jeff Layton
2018-05-17T15:46:50Z

From: Jeff Layton <jlayton@redhat.com>

All of the callback functions for iterate_supers either ignore the
opaque argument, or dereference the pointer only to fetch the int
to which it points.

Change iterate_supers to pass an opaque int arg to the callback
instead of a void pointer.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
---
fs/drop_caches.c | 4 ++--
fs/quota/quota.c | 6 ++----
fs/super.c | 3 ++-
fs/sync.c | 32 ++++++++++++++------------------
include/linux/fs.h | 2 +-
mm/cleancache.c | 4 ++--
security/selinux/hooks.c | 4 ++--
7 files changed, 25 insertions(+), 30 deletions(-)

diff --git a/fs/drop_caches.c b/fs/drop_caches.c
index 82377017130f..1850e7276fdf 100644
--- a/fs/drop_caches.c
+++ b/fs/drop_caches.c
@@ -14,7 +14,7 @@
/* A global variable is a bit ugly, but it keeps the code simple */
int sysctl_drop_caches;

-static void drop_pagecache_sb(struct super_block *sb, void *unused)
+static void drop_pagecache_sb(struct super_block *sb, int unused)
{
struct inode *inode, *toput_inode = NULL;

@@ -52,7 +52,7 @@ int drop_caches_sysctl_handler(struct ctl_table *table, int write,
static int stfu;

if (sysctl_drop_caches & 1) {
- iterate_supers(drop_pagecache_sb, NULL);
+ iterate_supers(drop_pagecache_sb, 0);
count_vm_event(DROP_PAGECACHE);
}
if (sysctl_drop_caches & 2) {
diff --git a/fs/quota/quota.c b/fs/quota/quota.c
index 860bfbe7a07a..5f1e1c494c07 100644
--- a/fs/quota/quota.c
+++ b/fs/quota/quota.c
@@ -46,10 +46,8 @@ static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
return security_quotactl(cmd, type, id, sb);
}

-static void quota_sync_one(struct super_block *sb, void *arg)
+static void quota_sync_one(struct super_block *sb, int type)
{
- int type = *(int *)arg;
-
if (sb->s_qcop && sb->s_qcop->quota_sync &&
(sb->s_quota_types & (1 << type)))
sb->s_qcop->quota_sync(sb, type);
@@ -63,7 +61,7 @@ static int quota_sync_all(int type)
return -EINVAL;
ret = security_quotactl(Q_SYNC, type, 0, NULL);
if (!ret)
- iterate_supers(quota_sync_one, &type);
+ iterate_supers(quota_sync_one, type);
return ret;
}

diff --git a/fs/super.c b/fs/super.c
index 122c402049a2..30b7490bd049 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -596,6 +596,7 @@ static void __iterate_supers(void (*f)(struct super_block *))
__put_super(p);
spin_unlock(&sb_lock);
}
+
/**
* iterate_supers - call function for all active superblocks
* @f: function to call
@@ -604,7 +605,7 @@ static void __iterate_supers(void (*f)(struct super_block *))
* Scans the superblock list and calls given function, passing it
* locked superblock and given argument.
*/
-void iterate_supers(void (*f)(struct super_block *, void *), void *arg)
+void iterate_supers(void (*f)(struct super_block *, int), int arg)
{
struct super_block *sb, *p = NULL;

diff --git a/fs/sync.c b/fs/sync.c
index b54e0541ad89..8c418da67e41 100644
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -68,16 +68,16 @@ int sync_filesystem(struct super_block *sb)
}
EXPORT_SYMBOL(sync_filesystem);

-static void sync_inodes_one_sb(struct super_block *sb, void *arg)
+static void sync_inodes_one_sb(struct super_block *sb, int unused)
{
if (!sb_rdonly(sb))
sync_inodes_sb(sb);
}

-static void sync_fs_one_sb(struct super_block *sb, void *arg)
+static void sync_fs_one_sb(struct super_block *sb, int arg)
{
if (!sb_rdonly(sb) && sb->s_op->sync_fs)
- sb->s_op->sync_fs(sb, *(int *)arg);
+ sb->s_op->sync_fs(sb, arg);
}

static void fdatawrite_one_bdev(struct block_device *bdev, void *arg)
@@ -107,14 +107,12 @@ static void fdatawait_one_bdev(struct block_device *bdev, void *arg)
*/
void ksys_sync(void)
{
- int nowait = 0, wait = 1;
-
wakeup_flusher_threads(WB_REASON_SYNC);
- iterate_supers(sync_inodes_one_sb, NULL);
- iterate_supers(sync_fs_one_sb, &nowait);
- iterate_supers(sync_fs_one_sb, &wait);
- iterate_bdevs(fdatawrite_one_bdev, NULL);
- iterate_bdevs(fdatawait_one_bdev, NULL);
+ iterate_supers(sync_inodes_one_sb, 0);
+ iterate_supers(sync_fs_one_sb, 0);
+ iterate_supers(sync_fs_one_sb, 1);
+ iterate_bdevs(fdatawrite_one_bdev, 0);
+ iterate_bdevs(fdatawait_one_bdev, 0);
if (unlikely(laptop_mode))
laptop_sync_completion();
}
@@ -127,18 +125,16 @@ SYSCALL_DEFINE0(sync)

static void do_sync_work(struct work_struct *work)
{
- int nowait = 0;
-
/*
* Sync twice to reduce the possibility we skipped some inodes / pages
* because they were temporarily locked
*/
- iterate_supers(sync_inodes_one_sb, &nowait);
- iterate_supers(sync_fs_one_sb, &nowait);
- iterate_bdevs(fdatawrite_one_bdev, NULL);
- iterate_supers(sync_inodes_one_sb, &nowait);
- iterate_supers(sync_fs_one_sb, &nowait);
- iterate_bdevs(fdatawrite_one_bdev, NULL);
+ iterate_supers(sync_inodes_one_sb, 0);
+ iterate_supers(sync_fs_one_sb, 0);
+ iterate_bdevs(fdatawrite_one_bdev, 0);
+ iterate_supers(sync_inodes_one_sb, 0);
+ iterate_supers(sync_fs_one_sb, 0);
+ iterate_bdevs(fdatawrite_one_bdev, 0);
printk("Emergency Sync complete\n");
kfree(work);
}
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 760d8da1b6c7..7107d291d853 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -3115,7 +3115,7 @@ extern struct super_block *get_super_exclusive_thawed(struct block_device *bdev)
extern struct super_block *get_active_super(struct block_device *bdev);
extern void drop_super(struct super_block *sb);
extern void drop_super_exclusive(struct super_block *sb);
-extern void iterate_supers(void (*)(struct super_block *, void *), void *);
+extern void iterate_supers(void (*)(struct super_block *, int), int);
extern void iterate_supers_type(struct file_system_type *,
void (*)(struct super_block *, void *), void *);

diff --git a/mm/cleancache.c b/mm/cleancache.c
index f7b9fdc79d97..92d27cc10274 100644
--- a/mm/cleancache.c
+++ b/mm/cleancache.c
@@ -34,7 +34,7 @@ static u64 cleancache_failed_gets;
static u64 cleancache_puts;
static u64 cleancache_invalidates;

-static void cleancache_register_ops_sb(struct super_block *sb, void *unused)
+static void cleancache_register_ops_sb(struct super_block *sb, int unused)
{
switch (sb->cleancache_poolid) {
case CLEANCACHE_NO_BACKEND:
@@ -105,7 +105,7 @@ int cleancache_register_ops(const struct cleancache_ops *ops)
* until the corresponding ->init_fs has been actually called and
* cleancache_ops has been set.
*/
- iterate_supers(cleancache_register_ops_sb, NULL);
+ iterate_supers(cleancache_register_ops_sb, 0);
return 0;
}
EXPORT_SYMBOL(cleancache_register_ops);
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 4cafe6a19167..91c13b72b427 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -7138,7 +7138,7 @@ static __init int selinux_init(void)
return 0;
}

-static void delayed_superblock_init(struct super_block *sb, void *unused)
+static void delayed_superblock_init(struct super_block *sb, int unused)
{
superblock_doinit(sb, NULL);
}
@@ -7149,7 +7149,7 @@ void selinux_complete_init(void)

/* Set up any superblocks initialized prior to the policy load. */
printk(KERN_DEBUG "SELinux: Setting up existing superblocks.\n");
- iterate_supers(delayed_superblock_init, NULL);
+ iterate_supers(delayed_superblock_init, 0);
}

/* SELinux requires early initialization in order to label
--
2.17.0