super: use a common iterator (Part 1)

Use a common iterator for all callbacks.

Link: https://lore.kernel.org/r/20250329-work-freeze-v2-4-a47af37ecc3d@kernel.org
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Christian Brauner 2025-03-29 09:42:17 +01:00
parent 6920e3388b
commit 2992476528
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GPG Key ID: 91C61BC06578DCA2
2 changed files with 18 additions and 55 deletions

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@ -887,37 +887,7 @@ void drop_super_exclusive(struct super_block *sb)
} }
EXPORT_SYMBOL(drop_super_exclusive); EXPORT_SYMBOL(drop_super_exclusive);
static void __iterate_supers(void (*f)(struct super_block *)) void __iterate_supers(void (*f)(struct super_block *, void *), void *arg, bool excl)
{
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)
{ {
struct super_block *sb, *p = NULL; 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)) if (super_flags(sb, SB_DYING))
continue; continue;
sb->s_count++; sb->s_count++;
spin_unlock(&sb_lock); spin_unlock(&sb_lock);
locked = super_lock_shared(sb); locked = super_lock(sb, excl);
if (locked) { if (locked) {
f(sb, arg); f(sb, arg);
super_unlock_shared(sb); super_unlock(sb, excl);
} }
spin_lock(&sb_lock); spin_lock(&sb_lock);
@ -1111,11 +1080,9 @@ int reconfigure_super(struct fs_context *fc)
return retval; 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 (sb->s_bdev && !sb_rdonly(sb)) {
if (locked && sb->s_root && sb->s_bdev && !sb_rdonly(sb)) {
struct fs_context *fc; struct fs_context *fc;
fc = fs_context_for_reconfigure(sb->s_root, 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); put_fs_context(fc);
} }
} }
if (locked)
super_unlock_excl(sb);
} }
static void do_emergency_remount(struct work_struct *work) 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); kfree(work);
printk("Emergency Remount complete\n"); 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 (IS_ENABLED(CONFIG_BLOCK))
while (sb->s_bdev && !bdev_thaw(sb->s_bdev))
if (locked && sb->s_root) { pr_warn("Emergency Thaw on %pg\n", sb->s_bdev);
if (IS_ENABLED(CONFIG_BLOCK)) thaw_super_locked(sb, FREEZE_HOLDER_USERSPACE);
while (sb->s_bdev && !bdev_thaw(sb->s_bdev)) return;
pr_warn("Emergency Thaw on %pg\n", sb->s_bdev);
thaw_super_locked(sb, FREEZE_HOLDER_USERSPACE);
return;
}
if (locked)
super_unlock_excl(sb);
} }
static void do_thaw_all(struct work_struct *work) 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); kfree(work);
printk(KERN_WARNING "Emergency Thaw complete\n"); printk(KERN_WARNING "Emergency Thaw complete\n");
} }

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@ -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 struct file_system_type *get_fs_type(const char *name);
extern void drop_super(struct super_block *sb); extern void drop_super(struct super_block *sb);
extern void drop_super_exclusive(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 *, extern void iterate_supers_type(struct file_system_type *,
void (*)(struct super_block *, void *), void *); void (*)(struct super_block *, void *), void *);