Merge tag 'mm-nonmm-stable-2023-06-24-19-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-mm updates from Andrew Morton:

 - Arnd Bergmann has fixed a bunch of -Wmissing-prototypes in top-level
   directories

 - Douglas Anderson has added a new "buddy" mode to the hardlockup
   detector. It permits the detector to work on architectures which
   cannot provide the required interrupts, by having CPUs periodically
   perform checks on other CPUs

 - Zhen Lei has enhanced kexec's ability to support two crash regions

 - Petr Mladek has done a lot of cleanup on the hard lockup detector's
   Kconfig entries

 - And the usual bunch of singleton patches in various places

* tag 'mm-nonmm-stable-2023-06-24-19-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (72 commits)
  kernel/time/posix-stubs.c: remove duplicated include
  ocfs2: remove redundant assignment to variable bit_off
  watchdog/hardlockup: fix typo in config HARDLOCKUP_DETECTOR_PREFER_BUDDY
  powerpc: move arch_trigger_cpumask_backtrace from nmi.h to irq.h
  devres: show which resource was invalid in __devm_ioremap_resource()
  watchdog/hardlockup: define HARDLOCKUP_DETECTOR_ARCH
  watchdog/sparc64: define HARDLOCKUP_DETECTOR_SPARC64
  watchdog/hardlockup: make HAVE_NMI_WATCHDOG sparc64-specific
  watchdog/hardlockup: declare arch_touch_nmi_watchdog() only in linux/nmi.h
  watchdog/hardlockup: make the config checks more straightforward
  watchdog/hardlockup: sort hardlockup detector related config values a logical way
  watchdog/hardlockup: move SMP barriers from common code to buddy code
  watchdog/buddy: simplify the dependency for HARDLOCKUP_DETECTOR_PREFER_BUDDY
  watchdog/buddy: don't copy the cpumask in watchdog_next_cpu()
  watchdog/buddy: cleanup how watchdog_buddy_check_hardlockup() is called
  watchdog/hardlockup: remove softlockup comment in touch_nmi_watchdog()
  watchdog/hardlockup: in watchdog_hardlockup_check() use cpumask_copy()
  watchdog/hardlockup: don't use raw_cpu_ptr() in watchdog_hardlockup_kick()
  watchdog/hardlockup: HAVE_NMI_WATCHDOG must implement watchdog_hardlockup_probe()
  watchdog/hardlockup: keep kernel.nmi_watchdog sysctl as 0444 if probe fails
  ...

9 files changed, 134 insertions, 19 deletions

diff --git a/fs/ocfs2/localalloc.c b/fs/ocfs2/localalloc.c
index c4426d12a2ad..c803c10dd97e 100644
--- a/fs/ocfs2/localalloc.c
+++ b/fs/ocfs2/localalloc.c
@@ -973,7 +973,7 @@ static int ocfs2_sync_local_to_main(struct ocfs2_super *osb,
 	la_start_blk = ocfs2_clusters_to_blocks(osb->sb,
 						le32_to_cpu(la->la_bm_off));
 	bitmap = la->la_bitmap;
-	start = count = bit_off = 0;
+	start = count = 0;
 	left = le32_to_cpu(alloc->id1.bitmap1.i_total);
 
 	while ((bit_off = ocfs2_find_next_zero_bit(bitmap, left, start))
diff --git a/fs/ocfs2/ocfs2_trace.h b/fs/ocfs2/ocfs2_trace.h
index b8c3d1702076..ac4fd1d5b128 100644
--- a/fs/ocfs2/ocfs2_trace.h
+++ b/fs/ocfs2/ocfs2_trace.h
@@ -1315,8 +1315,6 @@ DEFINE_OCFS2_FILE_OPS(ocfs2_sync_file);
 
 DEFINE_OCFS2_FILE_OPS(ocfs2_file_write_iter);
 
-DEFINE_OCFS2_FILE_OPS(ocfs2_file_splice_write);
-
 DEFINE_OCFS2_FILE_OPS(ocfs2_file_read_iter);
 
 DEFINE_OCFS2_FILE_OPS(ocfs2_file_splice_read);
diff --git a/fs/ocfs2/quota_local.c b/fs/ocfs2/quota_local.c
index 5022b3e9bfcd..dfaae1e52412 100644
--- a/fs/ocfs2/quota_local.c
+++ b/fs/ocfs2/quota_local.c
@@ -811,7 +811,7 @@ static int ocfs2_local_free_info(struct super_block *sb, int type)
 	struct ocfs2_quota_chunk *chunk;
 	struct ocfs2_local_disk_chunk *dchunk;
 	int mark_clean = 1, len;
-	int status;
+	int status = 0;
 
 	iput(oinfo->dqi_gqinode);
 	ocfs2_simple_drop_lockres(OCFS2_SB(sb), &oinfo->dqi_gqlock);
@@ -853,17 +853,14 @@ static int ocfs2_local_free_info(struct super_block *sb, int type)
 				 oinfo->dqi_libh,
 				 olq_update_info,
 				 info);
-	if (status < 0) {
+	if (status < 0)
 		mlog_errno(status);
-		goto out;
-	}
-
 out:
 	ocfs2_inode_unlock(sb_dqopt(sb)->files[type], 1);
 	brelse(oinfo->dqi_libh);
 	brelse(oinfo->dqi_lqi_bh);
 	kfree(oinfo);
-	return 0;
+	return status;
 }
 
 static void olq_set_dquot(struct buffer_head *bh, void *private)
diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c
index 25b44b303b35..5d0cf59c4926 100644
--- a/fs/proc/kcore.c
+++ b/fs/proc/kcore.c
@@ -419,7 +419,7 @@ static ssize_t read_kcore_iter(struct kiocb *iocb, struct iov_iter *iter)
 		char *notes;
 		size_t i = 0;
 
-		strlcpy(prpsinfo.pr_psargs, saved_command_line,
+		strscpy(prpsinfo.pr_psargs, saved_command_line,
 			sizeof(prpsinfo.pr_psargs));
 
 		notes = kzalloc(notes_len, GFP_KERNEL);
diff --git a/fs/squashfs/block.c b/fs/squashfs/block.c
index bed3bb8b27fa..6aa9c2e1e8eb 100644
--- a/fs/squashfs/block.c
+++ b/fs/squashfs/block.c
@@ -17,8 +17,8 @@
 #include <linux/fs.h>
 #include <linux/vfs.h>
 #include <linux/slab.h>
+#include <linux/pagemap.h>
 #include <linux/string.h>
-#include <linux/buffer_head.h>
 #include <linux/bio.h>
 
 #include "squashfs_fs.h"
@@ -76,10 +76,101 @@ static int copy_bio_to_actor(struct bio *bio,
 	return copied_bytes;
 }
 
+static int squashfs_bio_read_cached(struct bio *fullbio,
+		struct address_space *cache_mapping, u64 index, int length,
+		u64 read_start, u64 read_end, int page_count)
+{
+	struct page *head_to_cache = NULL, *tail_to_cache = NULL;
+	struct block_device *bdev = fullbio->bi_bdev;
+	int start_idx = 0, end_idx = 0;
+	struct bvec_iter_all iter_all;
+	struct bio *bio = NULL;
+	struct bio_vec *bv;
+	int idx = 0;
+	int err = 0;
+
+	bio_for_each_segment_all(bv, fullbio, iter_all) {
+		struct page *page = bv->bv_page;
+
+		if (page->mapping == cache_mapping) {
+			idx++;
+			continue;
+		}
+
+		/*
+		 * We only use this when the device block size is the same as
+		 * the page size, so read_start and read_end cover full pages.
+		 *
+		 * Compare these to the original required index and length to
+		 * only cache pages which were requested partially, since these
+		 * are the ones which are likely to be needed when reading
+		 * adjacent blocks.
+		 */
+		if (idx == 0 && index != read_start)
+			head_to_cache = page;
+		else if (idx == page_count - 1 && index + length != read_end)
+			tail_to_cache = page;
+
+		if (!bio || idx != end_idx) {
+			struct bio *new = bio_alloc_clone(bdev, fullbio,
+							  GFP_NOIO, &fs_bio_set);
+
+			if (bio) {
+				bio_trim(bio, start_idx * PAGE_SECTORS,
+					 (end_idx - start_idx) * PAGE_SECTORS);
+				bio_chain(bio, new);
+				submit_bio(bio);
+			}
+
+			bio = new;
+			start_idx = idx;
+		}
+
+		idx++;
+		end_idx = idx;
+	}
+
+	if (bio) {
+		bio_trim(bio, start_idx * PAGE_SECTORS,
+			 (end_idx - start_idx) * PAGE_SECTORS);
+		err = submit_bio_wait(bio);
+		bio_put(bio);
+	}
+
+	if (err)
+		return err;
+
+	if (head_to_cache) {
+		int ret = add_to_page_cache_lru(head_to_cache, cache_mapping,
+						read_start >> PAGE_SHIFT,
+						GFP_NOIO);
+
+		if (!ret) {
+			SetPageUptodate(head_to_cache);
+			unlock_page(head_to_cache);
+		}
+
+	}
+
+	if (tail_to_cache) {
+		int ret = add_to_page_cache_lru(tail_to_cache, cache_mapping,
+						(read_end >> PAGE_SHIFT) - 1,
+						GFP_NOIO);
+
+		if (!ret) {
+			SetPageUptodate(tail_to_cache);
+			unlock_page(tail_to_cache);
+		}
+	}
+
+	return 0;
+}
+
 static int squashfs_bio_read(struct super_block *sb, u64 index, int length,
 			     struct bio **biop, int *block_offset)
 {
 	struct squashfs_sb_info *msblk = sb->s_fs_info;
+	struct address_space *cache_mapping = msblk->cache_mapping;
 	const u64 read_start = round_down(index, msblk->devblksize);
 	const sector_t block = read_start >> msblk->devblksize_log2;
 	const u64 read_end = round_up(index + length, msblk->devblksize);
@@ -99,21 +190,34 @@ static int squashfs_bio_read(struct super_block *sb, u64 index, int length,
 	for (i = 0; i < page_count; ++i) {
 		unsigned int len =
 			min_t(unsigned int, PAGE_SIZE - offset, total_len);
-		struct page *page = alloc_page(GFP_NOIO);
+		struct page *page = NULL;
+
+		if (cache_mapping)
+			page = find_get_page(cache_mapping,
+					     (read_start >> PAGE_SHIFT) + i);
+		if (!page)
+			page = alloc_page(GFP_NOIO);
 
 		if (!page) {
 			error = -ENOMEM;
 			goto out_free_bio;
 		}
-		if (!bio_add_page(bio, page, len, offset)) {
-			error = -EIO;
-			goto out_free_bio;
-		}
+
+		/*
+		 * Use the __ version to avoid merging since we need each page
+		 * to be separate when we check for and avoid cached pages.
+		 */
+		__bio_add_page(bio, page, len, offset);
 		offset = 0;
 		total_len -= len;
 	}
 
-	error = submit_bio_wait(bio);
+	if (cache_mapping)
+		error = squashfs_bio_read_cached(bio, cache_mapping, index,
+						 length, read_start, read_end,
+						 page_count);
+	else
+		error = submit_bio_wait(bio);
 	if (error)
 		goto out_free_bio;
 
diff --git a/fs/squashfs/decompressor.c b/fs/squashfs/decompressor.c
index 8893cb9b4198..a676084be27e 100644
--- a/fs/squashfs/decompressor.c
+++ b/fs/squashfs/decompressor.c
@@ -11,7 +11,6 @@
 #include <linux/types.h>
 #include <linux/mutex.h>
 #include <linux/slab.h>
-#include <linux/buffer_head.h>
 
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"
diff --git a/fs/squashfs/decompressor_multi_percpu.c b/fs/squashfs/decompressor_multi_percpu.c
index 1dfadf76ed9a..8a218e7c2390 100644
--- a/fs/squashfs/decompressor_multi_percpu.c
+++ b/fs/squashfs/decompressor_multi_percpu.c
@@ -7,7 +7,6 @@
 #include <linux/types.h>
 #include <linux/slab.h>
 #include <linux/percpu.h>
-#include <linux/buffer_head.h>
 #include <linux/local_lock.h>
 
 #include "squashfs_fs.h"
diff --git a/fs/squashfs/squashfs_fs_sb.h b/fs/squashfs/squashfs_fs_sb.h
index 72f6f4b37863..c01998eec146 100644
--- a/fs/squashfs/squashfs_fs_sb.h
+++ b/fs/squashfs/squashfs_fs_sb.h
@@ -47,6 +47,7 @@ struct squashfs_sb_info {
 	struct squashfs_cache			*block_cache;
 	struct squashfs_cache			*fragment_cache;
 	struct squashfs_cache			*read_page;
+	struct address_space			*cache_mapping;
 	int					next_meta_index;
 	__le64					*id_table;
 	__le64					*fragment_index;
diff --git a/fs/squashfs/super.c b/fs/squashfs/super.c
index e090fae48e68..22e812808e5c 100644
--- a/fs/squashfs/super.c
+++ b/fs/squashfs/super.c
@@ -329,6 +329,19 @@ static int squashfs_fill_super(struct super_block *sb, struct fs_context *fc)
 		goto failed_mount;
 	}
 
+	if (msblk->devblksize == PAGE_SIZE) {
+		struct inode *cache = new_inode(sb);
+
+		if (cache == NULL)
+			goto failed_mount;
+
+		set_nlink(cache, 1);
+		cache->i_size = OFFSET_MAX;
+		mapping_set_gfp_mask(cache->i_mapping, GFP_NOFS);
+
+		msblk->cache_mapping = cache->i_mapping;
+	}
+
 	msblk->stream = squashfs_decompressor_setup(sb, flags);
 	if (IS_ERR(msblk->stream)) {
 		err = PTR_ERR(msblk->stream);
@@ -454,6 +467,8 @@ failed_mount:
 	squashfs_cache_delete(msblk->block_cache);
 	squashfs_cache_delete(msblk->fragment_cache);
 	squashfs_cache_delete(msblk->read_page);
+	if (msblk->cache_mapping)
+		iput(msblk->cache_mapping->host);
 	msblk->thread_ops->destroy(msblk);
 	kfree(msblk->inode_lookup_table);
 	kfree(msblk->fragment_index);
@@ -572,6 +587,8 @@ static void squashfs_put_super(struct super_block *sb)
 		squashfs_cache_delete(sbi->block_cache);
 		squashfs_cache_delete(sbi->fragment_cache);
 		squashfs_cache_delete(sbi->read_page);
+		if (sbi->cache_mapping)
+			iput(sbi->cache_mapping->host);
 		sbi->thread_ops->destroy(sbi);
 		kfree(sbi->id_table);
 		kfree(sbi->fragment_index);