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buffer: fix various functions for block size > PAGE_SIZE

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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@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Pankaj Raghav <p.raghav@samsung.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Matthew Wilcox (Oracle) 2023-11-09 21:06:06 +00:00 committed by Andrew Morton
parent 808441943f
commit 4b04646cae
1 changed files with 5 additions and 5 deletions
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8
fs/buffer.c
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@ -199,7 +199,7 @@ __find_get_block_slow(struct block_device *bdev, sector_t block)
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_device *bdev, sector_t block, sector_t len)
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);
@ -2660,7 +2660,7 @@ int block_truncate_page(struct address_space *mapping,
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))