[to-be-updated] squashfs-implement-readahead.patch removed from -mm tree

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



The quilt patch titled
     Subject: squashfs: implement readahead
has been removed from the -mm tree.  Its filename was
     squashfs-implement-readahead.patch

This patch was dropped because an updated version will be merged

------------------------------------------------------
From: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>
Subject: squashfs: implement readahead
Date: Mon, 6 Jun 2022 23:03:05 +0800

Implement readahead callback for squashfs. It will read datablocks
which cover pages in readahead request. For a few cases it will
not mark page as uptodate, including:
- file end is 0.
- zero filled blocks.
- current batch of pages isn't in the same datablock.
- decompressor error.
Otherwise pages will be marked as uptodate. The unhandled pages will be
updated by readpage later.

Link: https://lkml.kernel.org/r/20220606150305.1883410-4-hsinyi@xxxxxxxxxxxx
Signed-off-by: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>
Suggested-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Reported-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Reported-by: Phillip Lougher <phillip@xxxxxxxxxxxxxxx>
Reported-by: Xiongwei Song <Xiongwei.Song@xxxxxxxxxxxxx>
Reported-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Cc: Hou Tao <houtao1@xxxxxxxxxx>
Cc: Miao Xie <miaoxie@xxxxxxxxxx>
Cc: Zhang Yi <yi.zhang@xxxxxxxxxx>
Cc: Zheng Liang <zhengliang6@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

 fs/squashfs/file.c |  124 ++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 123 insertions(+), 1 deletion(-)

--- a/fs/squashfs/file.c~squashfs-implement-readahead
+++ a/fs/squashfs/file.c
@@ -39,6 +39,7 @@
 #include "squashfs_fs_sb.h"
 #include "squashfs_fs_i.h"
 #include "squashfs.h"
+#include "page_actor.h"
 
 /*
  * Locate cache slot in range [offset, index] for specified inode.  If
@@ -495,7 +496,128 @@ out:
 	return 0;
 }
 
+static void squashfs_readahead(struct readahead_control *ractl)
+{
+	struct inode *inode = ractl->mapping->host;
+	struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info;
+	size_t mask = (1UL << msblk->block_log) - 1;
+	unsigned short shift = msblk->block_log - PAGE_SHIFT;
+	loff_t start = readahead_pos(ractl) & ~mask;
+	size_t len = readahead_length(ractl) + readahead_pos(ractl) - start;
+	struct squashfs_page_actor *actor;
+	unsigned int nr_pages = 0;
+	struct page **pages;
+	int i, file_end = i_size_read(inode) >> msblk->block_log;
+	unsigned int max_pages = 1UL << shift;
+
+	readahead_expand(ractl, start, (len | mask) + 1);
+
+	if (file_end == 0)
+		return;
+
+	pages = kmalloc_array(max_pages, sizeof(void *), GFP_KERNEL);
+	if (!pages)
+		return;
+
+	actor = squashfs_page_actor_init_special(pages, max_pages, 0);
+	if (!actor)
+		goto out;
+
+	for (;;) {
+		pgoff_t index;
+		int res, bsize;
+		u64 block = 0;
+		unsigned int expected;
+
+		nr_pages = __readahead_batch(ractl, pages, max_pages);
+		if (!nr_pages)
+			break;
+
+		if (readahead_pos(ractl) >= i_size_read(inode))
+			goto skip_pages;
+
+		index = pages[0]->index >> shift;
+		if ((pages[nr_pages - 1]->index >> shift) != index)
+			goto skip_pages;
+
+		expected = index == file_end ?
+			   (i_size_read(inode) & (msblk->block_size - 1)) :
+			    msblk->block_size;
+
+		bsize = read_blocklist(inode, index, &block);
+		if (bsize == 0)
+			goto skip_pages;
+
+		if (nr_pages < max_pages) {
+			struct squashfs_cache_entry *buffer;
+			unsigned int block_mask = max_pages - 1;
+			int offset = pages[0]->index - (pages[0]->index & ~block_mask);
+
+			buffer = squashfs_get_datablock(inode->i_sb, block,
+							bsize);
+			if (buffer->error) {
+				squashfs_cache_put(buffer);
+				goto skip_pages;
+			}
+
+			expected -= offset * PAGE_SIZE;
+			for (i = 0; i < nr_pages && expected > 0; i++,
+						expected -= PAGE_SIZE, offset++) {
+				int avail = min_t(int, expected, PAGE_SIZE);
+
+				squashfs_fill_page(pages[i], buffer,
+						offset * PAGE_SIZE, avail);
+				unlock_page(pages[i]);
+			}
+
+			squashfs_cache_put(buffer);
+			continue;
+		}
+
+		res = squashfs_read_data(inode->i_sb, block, bsize, NULL,
+					 actor);
+
+		if (res == expected) {
+			int bytes;
+
+			/* Last page may have trailing bytes not filled */
+			bytes = res % PAGE_SIZE;
+			if (bytes) {
+				void *pageaddr;
+
+				pageaddr = kmap_atomic(pages[nr_pages - 1]);
+				memset(pageaddr + bytes, 0, PAGE_SIZE - bytes);
+				kunmap_atomic(pageaddr);
+			}
+
+			for (i = 0; i < nr_pages; i++) {
+				flush_dcache_page(pages[i]);
+				SetPageUptodate(pages[i]);
+			}
+		}
+
+		for (i = 0; i < nr_pages; i++) {
+			unlock_page(pages[i]);
+			put_page(pages[i]);
+		}
+	}
+
+	kfree(actor);
+	kfree(pages);
+	return;
+
+skip_pages:
+	for (i = 0; i < nr_pages; i++) {
+		unlock_page(pages[i]);
+		put_page(pages[i]);
+	}
+
+	kfree(actor);
+out:
+	kfree(pages);
+}
 
 const struct address_space_operations squashfs_aops = {
-	.read_folio = squashfs_read_folio
+	.read_folio = squashfs_read_folio,
+	.readahead = squashfs_readahead
 };
_

Patches currently in -mm which might be from hsinyi@xxxxxxxxxxxx are





[Index of Archives]     [Kernel Archive]     [IETF Annouce]     [DCCP]     [Netdev]     [Networking]     [Security]     [Bugtraq]     [Yosemite]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux SCSI]

  Powered by Linux