From 8d836581f9b1f57ceaa2b47654754ef1260b410b Mon Sep 17 00:00:00 2001 From: Niklas Cassel Date: Wed, 16 Sep 2026 15:00:32 +0200 Subject: ata: libata-scsi: fix ata_dsm_trim_pages() kernel-doc make htmldocs fails with: Documentation/driver-api/libata:604: ./drivers/ata/libata-scsi.c:2301: ERROR: Unexpected indentation. [docutils] The Return: section of ata_dsm_trim_pages() ends its first sentence with a colon and continues with an indented bullet list. reStructuredText requires a blank line before an indented block, so docutils chokes on the list. Simply adding the missing blank line does not work either: Return: is a kernel-doc "special section", which is terminated by the first blank line, so the bullet list would end up in the Description section, detached from the sentence introducing it. Spell the two bounds out as prose instead, so that the Return: section stays self-contained. Documentation-only change. Fixes: e64e6b5dc867 ("ata: libata-scsi: scale DSM TRIM payload by MAX PAGES PER DSM COMMAND") Reported-by: Thomas Huth Closes: https://lore.kernel.org/linux-ide/b0a0b8e8-cc4f-4c7b-8bc5-fee0712d405a@redhat.com/ Reviewed-by: Damien Le Moal Reviewed-by: Thomas Huth Link: https://lore.kernel.org/r/20260916130031.29990-2-cassel@kernel.org Signed-off-by: Niklas Cassel --- mm/shrinker_debug.c | 270 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 270 insertions(+) create mode 100644 mm/shrinker_debug.c (limited to 'mm/shrinker_debug.c') diff --git a/mm/shrinker_debug.c b/mm/shrinker_debug.c new file mode 100644 index 000000000..cafb56630 --- /dev/null +++ b/mm/shrinker_debug.c @@ -0,0 +1,270 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include +#include + +#include "internal.h" + +/* defined in vmscan.c */ +extern struct mutex shrinker_mutex; +extern struct list_head shrinker_list; + +static DEFINE_IDA(shrinker_debugfs_ida); +static struct dentry *shrinker_debugfs_root; + +static unsigned long shrinker_count_objects(struct shrinker *shrinker, + struct mem_cgroup *memcg, + unsigned long *count_per_node) +{ + unsigned long nr, total = 0; + int nid; + + for_each_node(nid) { + if (nid == 0 || (shrinker->flags & SHRINKER_NUMA_AWARE)) { + struct shrink_control sc = { + .gfp_mask = GFP_KERNEL, + .nid = nid, + .memcg = memcg, + }; + + nr = shrinker->count_objects(shrinker, &sc); + if (nr == SHRINK_EMPTY) + nr = 0; + } else { + nr = 0; + } + + count_per_node[nid] = nr; + total += nr; + } + + return total; +} + +static int shrinker_debugfs_count_show(struct seq_file *m, void *v) +{ + struct shrinker *shrinker = m->private; + unsigned long *count_per_node; + struct mem_cgroup *memcg; + unsigned long total; + bool memcg_aware; + int ret = 0, nid; + + count_per_node = kcalloc(nr_node_ids, sizeof(unsigned long), GFP_KERNEL); + if (!count_per_node) + return -ENOMEM; + + memcg_aware = shrinker->flags & SHRINKER_MEMCG_AWARE; + + memcg = mem_cgroup_iter(NULL, NULL, NULL); + do { + if (memcg && !mem_cgroup_online(memcg)) + continue; + + total = shrinker_count_objects(shrinker, + memcg_aware ? memcg : NULL, + count_per_node); + if (total) { + seq_printf(m, "%llu", mem_cgroup_id(memcg)); + for_each_node(nid) + seq_printf(m, " %lu", count_per_node[nid]); + seq_putc(m, '\n'); + } + + if (!memcg_aware) { + mem_cgroup_iter_break(NULL, memcg); + break; + } + + if (signal_pending(current)) { + mem_cgroup_iter_break(NULL, memcg); + ret = -EINTR; + break; + } + } while ((memcg = mem_cgroup_iter(NULL, memcg, NULL)) != NULL); + + kfree(count_per_node); + return ret; +} +DEFINE_SHOW_ATTRIBUTE(shrinker_debugfs_count); + +static int shrinker_debugfs_scan_open(struct inode *inode, struct file *file) +{ + file->private_data = inode->i_private; + return nonseekable_open(inode, file); +} + +static ssize_t shrinker_debugfs_scan_write(struct file *file, + const char __user *buf, + size_t size, loff_t *pos) +{ + struct shrinker *shrinker = file->private_data; + unsigned long nr_to_scan = 0, read_len; + u64 id; + struct shrink_control sc = { + .gfp_mask = GFP_KERNEL, + }; + struct mem_cgroup *memcg = NULL; + int nid; + char kbuf[72]; + + read_len = min(size, sizeof(kbuf) - 1); + if (copy_from_user(kbuf, buf, read_len)) + return -EFAULT; + kbuf[read_len] = '\0'; + + if (sscanf(kbuf, "%llu %d %lu", &id, &nid, &nr_to_scan) != 3) + return -EINVAL; + + if (nid < 0 || nid >= nr_node_ids) + return -EINVAL; + + if (nr_to_scan == 0) + return size; + + if (shrinker->flags & SHRINKER_MEMCG_AWARE) { + memcg = mem_cgroup_get_from_id(id); + if (!memcg) + return -ENOENT; + + if (!mem_cgroup_online(memcg)) { + mem_cgroup_put(memcg); + return -ENOENT; + } + } else if (id != 0) { + return -EINVAL; + } + + sc.nid = nid; + sc.memcg = memcg; + sc.nr_to_scan = nr_to_scan; + sc.nr_scanned = nr_to_scan; + + shrinker->scan_objects(shrinker, &sc); + + mem_cgroup_put(memcg); + + return size; +} + +static const struct file_operations shrinker_debugfs_scan_fops = { + .owner = THIS_MODULE, + .open = shrinker_debugfs_scan_open, + .write = shrinker_debugfs_scan_write, +}; + +int shrinker_debugfs_add(struct shrinker *shrinker) +{ + struct dentry *entry; + char buf[128]; + int id; + + lockdep_assert_held(&shrinker_mutex); + + /* debugfs isn't initialized yet, add debugfs entries later. */ + if (!shrinker_debugfs_root) + return 0; + + id = ida_alloc(&shrinker_debugfs_ida, GFP_KERNEL); + if (id < 0) + return id; + shrinker->debugfs_id = id; + + snprintf(buf, sizeof(buf), "%s-%d", shrinker->name, id); + + /* create debugfs entry */ + entry = debugfs_create_dir(buf, shrinker_debugfs_root); + if (IS_ERR(entry)) { + ida_free(&shrinker_debugfs_ida, id); + return PTR_ERR(entry); + } + shrinker->debugfs_entry = entry; + + if (shrinker->count_objects) + debugfs_create_file("count", 0440, entry, shrinker, + &shrinker_debugfs_count_fops); + if (shrinker->scan_objects) + debugfs_create_file("scan", 0220, entry, shrinker, + &shrinker_debugfs_scan_fops); + return 0; +} + +int shrinker_debugfs_rename(struct shrinker *shrinker, const char *fmt, ...) +{ + const char *new, *old; + va_list ap; + int ret = 0; + + va_start(ap, fmt); + new = kvasprintf_const(GFP_KERNEL, fmt, ap); + va_end(ap); + + if (!new) + return -ENOMEM; + + mutex_lock(&shrinker_mutex); + + old = shrinker->name; + shrinker->name = new; + + ret = debugfs_change_name(shrinker->debugfs_entry, "%s-%d", + shrinker->name, shrinker->debugfs_id); + + if (ret) { + shrinker->name = old; + kfree_const(new); + } else { + kfree_const(old); + } + mutex_unlock(&shrinker_mutex); + + return ret; +} +EXPORT_SYMBOL(shrinker_debugfs_rename); + +struct dentry *shrinker_debugfs_detach(struct shrinker *shrinker, + int *debugfs_id) +{ + struct dentry *entry = shrinker->debugfs_entry; + + lockdep_assert_held(&shrinker_mutex); + + *debugfs_id = entry ? shrinker->debugfs_id : -1; + shrinker->debugfs_entry = NULL; + + return entry; +} + +void shrinker_debugfs_remove(struct dentry *debugfs_entry, int debugfs_id) +{ + debugfs_remove_recursive(debugfs_entry); + ida_free(&shrinker_debugfs_ida, debugfs_id); +} + +static int __init shrinker_debugfs_init(void) +{ + struct shrinker *shrinker; + struct dentry *dentry; + int ret = 0; + + dentry = debugfs_create_dir("shrinker", NULL); + if (IS_ERR(dentry)) + return PTR_ERR(dentry); + shrinker_debugfs_root = dentry; + + /* Create debugfs entries for shrinkers registered at boot */ + mutex_lock(&shrinker_mutex); + list_for_each_entry(shrinker, &shrinker_list, list) + if (!shrinker->debugfs_entry) { + ret = shrinker_debugfs_add(shrinker); + if (ret) + break; + } + mutex_unlock(&shrinker_mutex); + + return ret; +} +late_initcall(shrinker_debugfs_init); -- cgit v1.3.1