The patch titled
Subject: buffer: fix various functions for block size > PAGE_SIZE
has been added to the -mm mm-unstable branch. Its filename is
buffer-fix-various-functions-for-block-size-page_size.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/buffer-fix-various-functions-for-block-size-page_size.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: buffer: fix various functions for block size > PAGE_SIZE
Date: Thu, 9 Nov 2023 21:06:06 +0000
If i_blkbits is larger than PAGE_SHIFT, we shift by a negative number,
which is undefined. It is safe to shift the block left as a block device
must be smaller than MAX_LFS_FILESIZE, which is guaranteed to fit in
loff_t.
Link: https://lkml.kernel.org/r/20231109210608.2252323-6-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Reviewed-by: Pankaj Raghav <p.raghav@xxxxxxxxxxx>
Cc: Hannes Reinecke <hare@xxxxxxx>
Cc: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Cc: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/buffer.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
--- a/fs/buffer.c~buffer-fix-various-functions-for-block-size-page_size
+++ a/fs/buffer.c
@@ -199,7 +199,7 @@ __find_get_block_slow(struct block_devic
int all_mapped = 1;
static DEFINE_RATELIMIT_STATE(last_warned, HZ, 1);
- index = block >> (PAGE_SHIFT - bd_inode->i_blkbits);
+ index = ((loff_t)block << bd_inode->i_blkbits) / PAGE_SIZE;
folio = __filemap_get_folio(bd_mapping, index, FGP_ACCESSED, 0);
if (IS_ERR(folio))
goto out;
@@ -1693,13 +1693,13 @@ void clean_bdev_aliases(struct block_dev
struct inode *bd_inode = bdev->bd_inode;
struct address_space *bd_mapping = bd_inode->i_mapping;
struct folio_batch fbatch;
- pgoff_t index = block >> (PAGE_SHIFT - bd_inode->i_blkbits);
+ pgoff_t index = ((loff_t)block << bd_inode->i_blkbits) / PAGE_SIZE;
pgoff_t end;
int i, count;
struct buffer_head *bh;
struct buffer_head *head;
- end = (block + len - 1) >> (PAGE_SHIFT - bd_inode->i_blkbits);
+ end = ((loff_t)(block + len - 1) << bd_inode->i_blkbits) / PAGE_SIZE;
folio_batch_init(&fbatch);
while (filemap_get_folios(bd_mapping, &index, end, &fbatch)) {
count = folio_batch_count(&fbatch);
@@ -2660,8 +2660,8 @@ int block_truncate_page(struct address_s
return 0;
length = blocksize - length;
- iblock = (sector_t)index << (PAGE_SHIFT - inode->i_blkbits);
-
+ iblock = ((loff_t)index * PAGE_SIZE) >> inode->i_blkbits;
+
folio = filemap_grab_folio(mapping, index);
if (IS_ERR(folio))
return PTR_ERR(folio);
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
mm-add-folio_zero_tail-and-use-it-in-ext4.patch
mm-add-folio_fill_tail-and-use-it-in-iomap.patch
gfs2-convert-stuffed_readpage-to-stuffed_read_folio.patch
mm-remove-test_set_page_writeback.patch
afs-do-not-test-the-return-value-of-folio_start_writeback.patch
smb-do-not-test-the-return-value-of-folio_start_writeback.patch
mm-return-void-from-folio_start_writeback-and-related-functions.patch
mm-make-mapping_evict_folio-the-preferred-way-to-evict-clean-folios.patch
mm-convert-__do_fault-to-use-a-folio.patch
mm-use-mapping_evict_folio-in-truncate_error_page.patch
mm-convert-soft_offline_in_use_page-to-use-a-folio.patch
mm-convert-isolate_page-to-mf_isolate_folio.patch
mm-remove-invalidate_inode_page.patch
buffer-return-bool-from-grow_dev_folio.patch
buffer-calculate-block-number-inside-folio_init_buffers.patch
buffer-fix-grow_buffers-for-block-size-page_size.patch
buffer-cast-block-to-loff_t-before-shifting-it.patch
buffer-fix-various-functions-for-block-size-page_size.patch
buffer-handle-large-folios-in-__block_write_begin_int.patch
buffer-fix-more-functions-for-block-size-page_size.patch
