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![Greg Kroah-Hartman](/assets/img/avatar_default.png)
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
191 lines
6.3 KiB
C
191 lines
6.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Copyright (c) 2013 Red Hat, Inc. and Parallels Inc. All rights reserved.
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* Authors: David Chinner and Glauber Costa
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*
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* Generic LRU infrastructure
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*/
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#ifndef _LRU_LIST_H
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#define _LRU_LIST_H
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#include <linux/list.h>
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#include <linux/nodemask.h>
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#include <linux/shrinker.h>
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struct mem_cgroup;
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/* list_lru_walk_cb has to always return one of those */
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enum lru_status {
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LRU_REMOVED, /* item removed from list */
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LRU_REMOVED_RETRY, /* item removed, but lock has been
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dropped and reacquired */
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LRU_ROTATE, /* item referenced, give another pass */
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LRU_SKIP, /* item cannot be locked, skip */
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LRU_RETRY, /* item not freeable. May drop the lock
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internally, but has to return locked. */
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};
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struct list_lru_one {
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struct list_head list;
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/* may become negative during memcg reparenting */
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long nr_items;
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};
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struct list_lru_memcg {
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/* array of per cgroup lists, indexed by memcg_cache_id */
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struct list_lru_one *lru[0];
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};
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struct list_lru_node {
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/* protects all lists on the node, including per cgroup */
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spinlock_t lock;
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/* global list, used for the root cgroup in cgroup aware lrus */
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struct list_lru_one lru;
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#if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
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/* for cgroup aware lrus points to per cgroup lists, otherwise NULL */
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struct list_lru_memcg *memcg_lrus;
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#endif
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long nr_items;
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} ____cacheline_aligned_in_smp;
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struct list_lru {
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struct list_lru_node *node;
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#if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
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struct list_head list;
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#endif
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};
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void list_lru_destroy(struct list_lru *lru);
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int __list_lru_init(struct list_lru *lru, bool memcg_aware,
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struct lock_class_key *key);
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#define list_lru_init(lru) __list_lru_init((lru), false, NULL)
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#define list_lru_init_key(lru, key) __list_lru_init((lru), false, (key))
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#define list_lru_init_memcg(lru) __list_lru_init((lru), true, NULL)
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int memcg_update_all_list_lrus(int num_memcgs);
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void memcg_drain_all_list_lrus(int src_idx, int dst_idx);
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/**
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* list_lru_add: add an element to the lru list's tail
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* @list_lru: the lru pointer
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* @item: the item to be added.
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*
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* If the element is already part of a list, this function returns doing
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* nothing. Therefore the caller does not need to keep state about whether or
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* not the element already belongs in the list and is allowed to lazy update
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* it. Note however that this is valid for *a* list, not *this* list. If
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* the caller organize itself in a way that elements can be in more than
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* one type of list, it is up to the caller to fully remove the item from
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* the previous list (with list_lru_del() for instance) before moving it
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* to @list_lru
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*
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* Return value: true if the list was updated, false otherwise
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*/
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bool list_lru_add(struct list_lru *lru, struct list_head *item);
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/**
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* list_lru_del: delete an element to the lru list
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* @list_lru: the lru pointer
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* @item: the item to be deleted.
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*
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* This function works analogously as list_lru_add in terms of list
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* manipulation. The comments about an element already pertaining to
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* a list are also valid for list_lru_del.
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*
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* Return value: true if the list was updated, false otherwise
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*/
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bool list_lru_del(struct list_lru *lru, struct list_head *item);
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/**
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* list_lru_count_one: return the number of objects currently held by @lru
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* @lru: the lru pointer.
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* @nid: the node id to count from.
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* @memcg: the cgroup to count from.
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*
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* Always return a non-negative number, 0 for empty lists. There is no
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* guarantee that the list is not updated while the count is being computed.
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* Callers that want such a guarantee need to provide an outer lock.
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*/
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unsigned long list_lru_count_one(struct list_lru *lru,
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int nid, struct mem_cgroup *memcg);
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unsigned long list_lru_count_node(struct list_lru *lru, int nid);
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static inline unsigned long list_lru_shrink_count(struct list_lru *lru,
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struct shrink_control *sc)
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{
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return list_lru_count_one(lru, sc->nid, sc->memcg);
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}
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static inline unsigned long list_lru_count(struct list_lru *lru)
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{
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long count = 0;
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int nid;
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for_each_node_state(nid, N_NORMAL_MEMORY)
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count += list_lru_count_node(lru, nid);
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return count;
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}
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void list_lru_isolate(struct list_lru_one *list, struct list_head *item);
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void list_lru_isolate_move(struct list_lru_one *list, struct list_head *item,
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struct list_head *head);
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typedef enum lru_status (*list_lru_walk_cb)(struct list_head *item,
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struct list_lru_one *list, spinlock_t *lock, void *cb_arg);
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/**
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* list_lru_walk_one: walk a list_lru, isolating and disposing freeable items.
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* @lru: the lru pointer.
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* @nid: the node id to scan from.
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* @memcg: the cgroup to scan from.
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* @isolate: callback function that is resposible for deciding what to do with
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* the item currently being scanned
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* @cb_arg: opaque type that will be passed to @isolate
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* @nr_to_walk: how many items to scan.
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*
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* This function will scan all elements in a particular list_lru, calling the
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* @isolate callback for each of those items, along with the current list
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* spinlock and a caller-provided opaque. The @isolate callback can choose to
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* drop the lock internally, but *must* return with the lock held. The callback
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* will return an enum lru_status telling the list_lru infrastructure what to
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* do with the object being scanned.
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*
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* Please note that nr_to_walk does not mean how many objects will be freed,
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* just how many objects will be scanned.
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*
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* Return value: the number of objects effectively removed from the LRU.
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*/
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unsigned long list_lru_walk_one(struct list_lru *lru,
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int nid, struct mem_cgroup *memcg,
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list_lru_walk_cb isolate, void *cb_arg,
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unsigned long *nr_to_walk);
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unsigned long list_lru_walk_node(struct list_lru *lru, int nid,
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list_lru_walk_cb isolate, void *cb_arg,
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unsigned long *nr_to_walk);
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static inline unsigned long
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list_lru_shrink_walk(struct list_lru *lru, struct shrink_control *sc,
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list_lru_walk_cb isolate, void *cb_arg)
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{
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return list_lru_walk_one(lru, sc->nid, sc->memcg, isolate, cb_arg,
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&sc->nr_to_scan);
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}
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static inline unsigned long
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list_lru_walk(struct list_lru *lru, list_lru_walk_cb isolate,
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void *cb_arg, unsigned long nr_to_walk)
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{
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long isolated = 0;
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int nid;
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for_each_node_state(nid, N_NORMAL_MEMORY) {
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isolated += list_lru_walk_node(lru, nid, isolate,
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cb_arg, &nr_to_walk);
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if (nr_to_walk <= 0)
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break;
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}
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return isolated;
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}
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#endif /* _LRU_LIST_H */
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