diff options
| author | Matthew Wilcox (Oracle) <willy@infradead.org> | 2023-11-09 21:06:06 +0000 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-12-29 11:58:23 -0800 |
| commit | 4b04646caed5449ca97b909bbadca0a7a2762159 (patch) | |
| tree | 5cd1ce53053440538719de2a4e410b0409806326 /fs/buffer.c | |
| parent | 808441943f6b817f4836752c6e0d1c07507f375e (diff) | |
| download | linux-4b04646caed5449ca97b909bbadca0a7a2762159.tar.gz linux-4b04646caed5449ca97b909bbadca0a7a2762159.tar.bz2 linux-4b04646caed5449ca97b909bbadca0a7a2762159.zip | |
buffer: fix various functions for block size > PAGE_SIZE
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>
Diffstat (limited to 'fs/buffer.c')
| -rw-r--r-- | fs/buffer.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/fs/buffer.c b/fs/buffer.c index 1662ddddfa27..d75264326643 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -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); @@ -2660,8 +2660,8 @@ 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)) return PTR_ERR(folio); |