Merge tag 'mm-nonmm-stable-2022-08-06-2' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc updates from Andrew Morton:
 "Updates to various subsystems which I help look after. lib, ocfs2,
  fatfs, autofs, squashfs, procfs, etc. A relatively small amount of
  material this time"

* tag 'mm-nonmm-stable-2022-08-06-2' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (72 commits)
  scripts/gdb: ensure the absolute path is generated on initial source
  MAINTAINERS: kunit: add David Gow as a maintainer of KUnit
  mailmap: add linux.dev alias for Brendan Higgins
  mailmap: update Kirill's email
  profile: setup_profiling_timer() is moslty not implemented
  ocfs2: fix a typo in a comment
  ocfs2: use the bitmap API to simplify code
  ocfs2: remove some useless functions
  lib/mpi: fix typo 'the the' in comment
  proc: add some (hopefully) insightful comments
  bdi: remove enum wb_congested_state
  kernel/hung_task: fix address space of proc_dohung_task_timeout_secs
  lib/lzo/lzo1x_compress.c: replace ternary operator with min() and min_t()
  squashfs: support reading fragments in readahead call
  squashfs: implement readahead
  squashfs: always build "file direct" version of page actor
  Revert "squashfs: provide backing_dev_info in order to disable read-ahead"
  fs/ocfs2: Fix spelling typo in comment
  ia64: old_rr4 added under CONFIG_HUGETLB_PAGE
  proc: fix test for "vsyscall=xonly" boot option
  ...

1 files changed, 20 insertions, 70 deletions

diff --git a/fs/squashfs/file_direct.c b/fs/squashfs/file_direct.c
index a4894cc59447..be4b12d31e0c 100644
--- a/fs/squashfs/file_direct.c
+++ b/fs/squashfs/file_direct.c
@@ -18,9 +18,6 @@
 #include "squashfs.h"
 #include "page_actor.h"
 
-static int squashfs_read_cache(struct page *target_page, u64 block, int bsize,
-	int pages, struct page **page, int bytes);
-
 /* Read separately compressed datablock directly into page cache */
 int squashfs_readpage_block(struct page *target_page, u64 block, int bsize,
 	int expected)
@@ -33,7 +30,7 @@ int squashfs_readpage_block(struct page *target_page, u64 block, int bsize,
 	int mask = (1 << (msblk->block_log - PAGE_SHIFT)) - 1;
 	int start_index = target_page->index & ~mask;
 	int end_index = start_index | mask;
-	int i, n, pages, missing_pages, bytes, res = -ENOMEM;
+	int i, n, pages, bytes, res = -ENOMEM;
 	struct page **page;
 	struct squashfs_page_actor *actor;
 	void *pageaddr;
@@ -47,50 +44,38 @@ int squashfs_readpage_block(struct page *target_page, u64 block, int bsize,
 	if (page == NULL)
 		return res;
 
-	/*
-	 * Create a "page actor" which will kmap and kunmap the
-	 * page cache pages appropriately within the decompressor
-	 */
-	actor = squashfs_page_actor_init_special(page, pages, 0);
-	if (actor == NULL)
-		goto out;
-
 	/* Try to grab all the pages covered by the Squashfs block */
-	for (missing_pages = 0, i = 0, n = start_index; i < pages; i++, n++) {
+	for (i = 0, n = start_index; n <= end_index; n++) {
 		page[i] = (n == target_page->index) ? target_page :
 			grab_cache_page_nowait(target_page->mapping, n);
 
-		if (page[i] == NULL) {
-			missing_pages++;
+		if (page[i] == NULL)
 			continue;
-		}
 
 		if (PageUptodate(page[i])) {
 			unlock_page(page[i]);
 			put_page(page[i]);
-			page[i] = NULL;
-			missing_pages++;
+			continue;
 		}
+
+		i++;
 	}
 
-	if (missing_pages) {
-		/*
-		 * Couldn't get one or more pages, this page has either
-		 * been VM reclaimed, but others are still in the page cache
-		 * and uptodate, or we're racing with another thread in
-		 * squashfs_readpage also trying to grab them.  Fall back to
-		 * using an intermediate buffer.
-		 */
-		res = squashfs_read_cache(target_page, block, bsize, pages,
-							page, expected);
-		if (res < 0)
-			goto mark_errored;
+	pages = i;
 
+	/*
+	 * Create a "page actor" which will kmap and kunmap the
+	 * page cache pages appropriately within the decompressor
+	 */
+	actor = squashfs_page_actor_init_special(msblk, page, pages, expected);
+	if (actor == NULL)
 		goto out;
-	}
 
 	/* Decompress directly into the page cache buffers */
 	res = squashfs_read_data(inode->i_sb, block, bsize, NULL, actor);
+
+	kfree(actor);
+
 	if (res < 0)
 		goto mark_errored;
 
@@ -99,12 +84,12 @@ int squashfs_readpage_block(struct page *target_page, u64 block, int bsize,
 		goto mark_errored;
 	}
 
-	/* Last page may have trailing bytes not filled */
+	/* Last page (if present) may have trailing bytes not filled */
 	bytes = res % PAGE_SIZE;
-	if (bytes) {
-		pageaddr = kmap_atomic(page[pages - 1]);
+	if (page[pages - 1]->index == end_index && bytes) {
+		pageaddr = kmap_local_page(page[pages - 1]);
 		memset(pageaddr + bytes, 0, PAGE_SIZE - bytes);
-		kunmap_atomic(pageaddr);
+		kunmap_local(pageaddr);
 	}
 
 	/* Mark pages as uptodate, unlock and release */
@@ -116,7 +101,6 @@ int squashfs_readpage_block(struct page *target_page, u64 block, int bsize,
 			put_page(page[i]);
 	}
 
-	kfree(actor);
 	kfree(page);
 
 	return 0;
@@ -135,40 +119,6 @@ mark_errored:
 	}
 
 out:
-	kfree(actor);
 	kfree(page);
 	return res;
 }
-
-
-static int squashfs_read_cache(struct page *target_page, u64 block, int bsize,
-	int pages, struct page **page, int bytes)
-{
-	struct inode *i = target_page->mapping->host;
-	struct squashfs_cache_entry *buffer = squashfs_get_datablock(i->i_sb,
-						 block, bsize);
-	int res = buffer->error, n, offset = 0;
-
-	if (res) {
-		ERROR("Unable to read page, block %llx, size %x\n", block,
-			bsize);
-		goto out;
-	}
-
-	for (n = 0; n < pages && bytes > 0; n++,
-			bytes -= PAGE_SIZE, offset += PAGE_SIZE) {
-		int avail = min_t(int, bytes, PAGE_SIZE);
-
-		if (page[n] == NULL)
-			continue;
-
-		squashfs_fill_page(page[n], buffer, offset, avail);
-		unlock_page(page[n]);
-		if (page[n] != target_page)
-			put_page(page[n]);
-	}
-
-out:
-	squashfs_cache_put(buffer);
-	return res;
-}