On Sat 29-03-25 09:42:17, Christian Brauner wrote:
> Use a common iterator for all callbacks.
>
> Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
Very nice! Feel free to add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> fs/super.c | 67 +++++++++++-------------------------------------------
> include/linux/fs.h | 6 ++++-
> 2 files changed, 18 insertions(+), 55 deletions(-)
>
> diff --git a/fs/super.c b/fs/super.c
> index c67ea3cdda41..0dd208804a74 100644
> --- a/fs/super.c
> +++ b/fs/super.c
> @@ -887,37 +887,7 @@ void drop_super_exclusive(struct super_block *sb)
> }
> EXPORT_SYMBOL(drop_super_exclusive);
>
> -static void __iterate_supers(void (*f)(struct super_block *))
> -{
> - struct super_block *sb, *p = NULL;
> -
> - spin_lock(&sb_lock);
> - list_for_each_entry(sb, &super_blocks, s_list) {
> - if (super_flags(sb, SB_DYING))
> - continue;
> - sb->s_count++;
> - spin_unlock(&sb_lock);
> -
> - f(sb);
> -
> - spin_lock(&sb_lock);
> - if (p)
> - __put_super(p);
> - p = sb;
> - }
> - if (p)
> - __put_super(p);
> - spin_unlock(&sb_lock);
> -}
> -/**
> - * iterate_supers - call function for all active superblocks
> - * @f: function to call
> - * @arg: argument to pass to it
> - *
> - * 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 *, void *), void *arg, bool excl)
> {
> struct super_block *sb, *p = NULL;
>
> @@ -927,14 +897,13 @@ void iterate_supers(void (*f)(struct super_block *, void *), void *arg)
>
> if (super_flags(sb, SB_DYING))
> continue;
> -
> sb->s_count++;
> spin_unlock(&sb_lock);
>
> - locked = super_lock_shared(sb);
> + locked = super_lock(sb, excl);
> if (locked) {
> f(sb, arg);
> - super_unlock_shared(sb);
> + super_unlock(sb, excl);
> }
>
> spin_lock(&sb_lock);
> @@ -1111,11 +1080,9 @@ int reconfigure_super(struct fs_context *fc)
> return retval;
> }
>
> -static void do_emergency_remount_callback(struct super_block *sb)
> +static void do_emergency_remount_callback(struct super_block *sb, void *unused)
> {
> - bool locked = super_lock_excl(sb);
> -
> - if (locked && sb->s_root && sb->s_bdev && !sb_rdonly(sb)) {
> + if (sb->s_bdev && !sb_rdonly(sb)) {
> struct fs_context *fc;
>
> fc = fs_context_for_reconfigure(sb->s_root,
> @@ -1126,13 +1093,11 @@ static void do_emergency_remount_callback(struct super_block *sb)
> put_fs_context(fc);
> }
> }
> - if (locked)
> - super_unlock_excl(sb);
> }
>
> static void do_emergency_remount(struct work_struct *work)
> {
> - __iterate_supers(do_emergency_remount_callback);
> + __iterate_supers(do_emergency_remount_callback, NULL, true);
> kfree(work);
> printk("Emergency Remount complete\n");
> }
> @@ -1148,24 +1113,18 @@ void emergency_remount(void)
> }
> }
>
> -static void do_thaw_all_callback(struct super_block *sb)
> +static void do_thaw_all_callback(struct super_block *sb, void *unused)
> {
> - bool locked = super_lock_excl(sb);
> -
> - if (locked && sb->s_root) {
> - if (IS_ENABLED(CONFIG_BLOCK))
> - while (sb->s_bdev && !bdev_thaw(sb->s_bdev))
> - pr_warn("Emergency Thaw on %pg\n", sb->s_bdev);
> - thaw_super_locked(sb, FREEZE_HOLDER_USERSPACE);
> - return;
> - }
> - if (locked)
> - super_unlock_excl(sb);
> + if (IS_ENABLED(CONFIG_BLOCK))
> + while (sb->s_bdev && !bdev_thaw(sb->s_bdev))
> + pr_warn("Emergency Thaw on %pg\n", sb->s_bdev);
> + thaw_super_locked(sb, FREEZE_HOLDER_USERSPACE);
> + return;
> }
>
> static void do_thaw_all(struct work_struct *work)
> {
> - __iterate_supers(do_thaw_all_callback);
> + __iterate_supers(do_thaw_all_callback, NULL, true);
> kfree(work);
> printk(KERN_WARNING "Emergency Thaw complete\n");
> }
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index 016b0fe1536e..0351500b71d2 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -3515,7 +3515,11 @@ extern void put_filesystem(struct file_system_type *fs);
> extern struct file_system_type *get_fs_type(const char *name);
> 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 *);
> +void __iterate_supers(void (*f)(struct super_block *, void *), void *arg, bool excl);
> +static inline void iterate_supers(void (*f)(struct super_block *, void *), void *arg)
> +{
> + __iterate_supers(f, arg, false);
> +}
> extern void iterate_supers_type(struct file_system_type *,
> void (*)(struct super_block *, void *), void *);
>
>
> --
> 2.47.2
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
