From 382497ada051a6fc79612aba5e30cdfa26364374 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Thu, 9 Nov 2023 21:06:03 +0000 Subject: [PATCH] buffer: calculate block number inside folio_init_buffers() The calculation of block from index doesn't work for devices with a block size larger than PAGE_SIZE as we end up shifting by a negative number. Instead, calculate the number of the first block from the folio's position in the block device. We no longer need to pass sizebits to grow_dev_folio(). Link: https://lkml.kernel.org/r/20231109210608.2252323-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Pankaj Raghav Cc: Hannes Reinecke Cc: Luis Chamberlain Cc: Ryusuke Konishi Signed-off-by: Andrew Morton --- fs/buffer.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/fs/buffer.c b/fs/buffer.c index 8dad6c691e14..44e0c0b7f71f 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -995,11 +995,12 @@ static sector_t blkdev_max_block(struct block_device *bdev, unsigned int size) * Initialise the state of a blockdev folio's buffers. */ static sector_t folio_init_buffers(struct folio *folio, - struct block_device *bdev, sector_t block, int size) + struct block_device *bdev, unsigned size) { struct buffer_head *head = folio_buffers(folio); struct buffer_head *bh = head; bool uptodate = folio_test_uptodate(folio); + sector_t block = div_u64(folio_pos(folio), size); sector_t end_block = blkdev_max_block(bdev, size); do { @@ -1032,7 +1033,7 @@ static sector_t folio_init_buffers(struct folio *folio, * we succeeded, or the caller should retry. */ static bool grow_dev_folio(struct block_device *bdev, sector_t block, - pgoff_t index, unsigned size, int sizebits, gfp_t gfp) + pgoff_t index, unsigned size, gfp_t gfp) { struct inode *inode = bdev->bd_inode; struct folio *folio; @@ -1047,8 +1048,7 @@ static bool grow_dev_folio(struct block_device *bdev, sector_t block, bh = folio_buffers(folio); if (bh) { if (bh->b_size == size) { - end_block = folio_init_buffers(folio, bdev, - (sector_t)index << sizebits, size); + end_block = folio_init_buffers(folio, bdev, size); goto unlock; } @@ -1069,8 +1069,7 @@ static bool grow_dev_folio(struct block_device *bdev, sector_t block, */ spin_lock(&inode->i_mapping->private_lock); link_dev_buffers(folio, bh); - end_block = folio_init_buffers(folio, bdev, - (sector_t)index << sizebits, size); + end_block = folio_init_buffers(folio, bdev, size); spin_unlock(&inode->i_mapping->private_lock); unlock: folio_unlock(folio); @@ -1105,7 +1104,7 @@ static bool grow_buffers(struct block_device *bdev, sector_t block, } /* Create a folio with the proper size buffers */ - return grow_dev_folio(bdev, block, index, size, sizebits, gfp); + return grow_dev_folio(bdev, block, index, size, gfp); } static struct buffer_head *