The quilt patch titled
Subject: buffer: fix grow_buffers() for block size > PAGE_SIZE
has been removed from the -mm tree. Its filename was
buffer-fix-grow_buffers-for-block-size-page_size.patch
This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: buffer: fix grow_buffers() for block size > PAGE_SIZE
Date: Thu, 9 Nov 2023 21:06:04 +0000
We must not shift by a negative number so work in terms of a byte offset
to avoid the awkward shift left-or-right-depending-on-sign option. This
means we need to use check_mul_overflow() to ensure that a large block
number does not result in a wrap.
Link: https://lkml.kernel.org/r/20231109210608.2252323-4-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>
Cc: Hannes Reinecke <hare@xxxxxxx>
Cc: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Cc: Pankaj Raghav <p.raghav@xxxxxxxxxxx>
Cc: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxx>
[nathan@xxxxxxxxxx: add cast in grow_buffers() to avoid a multiplication libcall]
Link: https://lkml.kernel.org/r/20231128-avoid-muloti4-grow_buffers-v1-1-bc3d0f0ec483@xxxxxxxxxx
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/buffer.c | 17 ++++++-----------
1 file changed, 6 insertions(+), 11 deletions(-)
--- a/fs/buffer.c~buffer-fix-grow_buffers-for-block-size-page_size
+++ a/fs/buffer.c
@@ -1085,26 +1085,21 @@ unlock:
static bool grow_buffers(struct block_device *bdev, sector_t block,
unsigned size, gfp_t gfp)
{
- pgoff_t index;
- int sizebits;
-
- sizebits = PAGE_SHIFT - __ffs(size);
- index = block >> sizebits;
+ loff_t pos;
/*
- * Check for a block which wants to lie outside our maximum possible
- * pagecache index. (this comparison is done using sector_t types).
+ * Check for a block which lies outside our maximum possible
+ * pagecache index.
*/
- if (unlikely(index != block >> sizebits)) {
- printk(KERN_ERR "%s: requested out-of-range block %llu for "
- "device %pg\n",
+ if (check_mul_overflow(block, (sector_t)size, &pos) || pos > MAX_LFS_FILESIZE) {
+ printk(KERN_ERR "%s: requested out-of-range block %llu for device %pg\n",
__func__, (unsigned long long)block,
bdev);
return false;
}
/* Create a folio with the proper size buffers */
- return grow_dev_folio(bdev, block, index, size, gfp);
+ return grow_dev_folio(bdev, block, pos / PAGE_SIZE, size, gfp);
}
static struct buffer_head *
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
mm-remove-inc-dec-lruvec-page-state-functions.patch
slub-use-alloc_pages_node-in-alloc_slab_page.patch
slub-use-folio-apis-in-free_large_kmalloc.patch
slub-use-a-folio-in-__kmalloc_large_node.patch
mm-khugepaged-use-a-folio-more-in-collapse_file.patch
mm-memcontrol-remove-__mod_lruvec_page_state.patch
