The patch titled Subject: buffer: calculate block number inside folio_init_buffers() has been added to the -mm mm-unstable branch. Its filename is buffer-calculate-block-number-inside-folio_init_buffers.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/buffer-calculate-block-number-inside-folio_init_buffers.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> Subject: buffer: calculate block number inside folio_init_buffers() Date: Thu, 9 Nov 2023 21:06:03 +0000 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@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 | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) --- a/fs/buffer.c~buffer-calculate-block-number-inside-folio_init_buffers +++ a/fs/buffer.c @@ -995,11 +995,12 @@ static sector_t blkdev_max_block(struct * 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(struc * 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_ 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_ */ 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_de } /* 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 * _ 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