The patch titled
Subject: squashfs: support reading fragments in readahead call
has been added to the -mm mm-nonmm-unstable branch. Its filename is
squashfs-support-reading-fragments-in-readahead-call.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/squashfs-support-reading-fragments-in-readahead-call.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Phillip Lougher <phillip@xxxxxxxxxxxxxxx>
Subject: squashfs: support reading fragments in readahead call
Date: Fri, 17 Jun 2022 16:38:15 +0800
Add a function which can be used to read fragments in the readahead call.
This function is necessary because filesystems built with the -tailends
(or -always-use-fragments) option may have fragments present which cannot
be currently handled.
Link: https://lkml.kernel.org/r/20220617083810.337573-5-hsinyi@xxxxxxxxxxxx
Signed-off-by: Phillip Lougher <phillip@xxxxxxxxxxxxxxx>
Signed-off-by: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>
Cc: Hou Tao <houtao1@xxxxxxxxxx>
Cc: kernel test robot <lkp@xxxxxxxxx>
Cc: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Miao Xie <miaoxie@xxxxxxxxxx>
Cc: Xiongwei Song <Xiongwei.Song@xxxxxxxxxxxxx>
Cc: Zhang Yi <yi.zhang@xxxxxxxxxx>
Cc: Zheng Liang <zhengliang6@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/squashfs/file.c | 47 ++++++++++++++++++++++++++++++++++++++++---
1 file changed, 44 insertions(+), 3 deletions(-)
--- a/fs/squashfs/file.c~squashfs-support-reading-fragments-in-readahead-call
+++ a/fs/squashfs/file.c
@@ -496,6 +496,41 @@ out:
return 0;
}
+static int squashfs_readahead_fragment(struct page **page,
+ unsigned int pages, unsigned int expected)
+{
+ struct inode *inode = page[0]->mapping->host;
+ struct squashfs_cache_entry *buffer = squashfs_get_fragment(inode->i_sb,
+ squashfs_i(inode)->fragment_block,
+ squashfs_i(inode)->fragment_size);
+ struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info;
+ unsigned int n, mask = (1 << (msblk->block_log - PAGE_SHIFT)) - 1;
+
+ if (buffer->error)
+ goto out;
+
+ expected += squashfs_i(inode)->fragment_offset;
+
+ for (n = 0; n < pages; n++) {
+ unsigned int base = (page[n]->index & mask) << PAGE_SHIFT;
+ unsigned int offset = base + squashfs_i(inode)->fragment_offset;
+
+ if (expected > offset) {
+ unsigned int avail = min_t(unsigned int, expected -
+ offset, PAGE_SIZE);
+
+ squashfs_fill_page(page[n], buffer, offset, avail);
+ }
+
+ unlock_page(page[n]);
+ put_page(page[n]);
+ }
+
+out:
+ squashfs_cache_put(buffer);
+ return buffer->error;
+}
+
static void squashfs_readahead(struct readahead_control *ractl)
{
struct inode *inode = ractl->mapping->host;
@@ -512,9 +547,6 @@ static void squashfs_readahead(struct re
readahead_expand(ractl, start, (len | mask) + 1);
- if (file_end == 0)
- return;
-
pages = kmalloc_array(max_pages, sizeof(void *), GFP_KERNEL);
if (!pages)
return;
@@ -540,6 +572,15 @@ static void squashfs_readahead(struct re
(i_size_read(inode) & (msblk->block_size - 1)) :
msblk->block_size;
+ if (index == file_end && squashfs_i(inode)->fragment_block !=
+ SQUASHFS_INVALID_BLK) {
+ res = squashfs_readahead_fragment(pages, nr_pages,
+ expected);
+ if (res)
+ goto skip_pages;
+ continue;
+ }
+
bsize = read_blocklist(inode, index, &block);
if (bsize == 0)
goto skip_pages;
_
Patches currently in -mm which might be from phillip@xxxxxxxxxxxxxxx are
squashfs-always-build-file-direct-version-of-page-actor.patch
squashfs-support-reading-fragments-in-readahead-call.patch
