From fa399c3112344fa420944e99cd529d679411ebe6 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Thu, 9 Nov 2023 21:06:08 +0000 Subject: buffer: fix more functions for block size > PAGE_SIZE Both __block_write_full_folio() and block_read_full_folio() assumed that block size <= PAGE_SIZE. Replace the shift with a divide, which is probably cheaper than first calculating the shift. That lets us remove block_size_bits() as these were the last callers. Link: https://lkml.kernel.org/r/20231109210608.2252323-8-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Cc: Hannes Reinecke Cc: Luis Chamberlain Cc: Pankaj Raghav Cc: Ryusuke Konishi Signed-off-by: Andrew Morton --- fs/buffer.c | 27 ++++++--------------------- 1 file changed, 6 insertions(+), 21 deletions(-) (limited to 'fs') diff --git a/fs/buffer.c b/fs/buffer.c index 9f4784150194..3a8c8322ed28 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -1742,19 +1742,6 @@ unlock_page: } EXPORT_SYMBOL(clean_bdev_aliases); -/* - * Size is a power-of-two in the range 512..PAGE_SIZE, - * and the case we care about most is PAGE_SIZE. - * - * So this *could* possibly be written with those - * constraints in mind (relevant mostly if some - * architecture has a slow bit-scan instruction) - */ -static inline int block_size_bits(unsigned int blocksize) -{ - return ilog2(blocksize); -} - static struct buffer_head *folio_create_buffers(struct folio *folio, struct inode *inode, unsigned int b_state) @@ -1807,7 +1794,7 @@ int __block_write_full_folio(struct inode *inode, struct folio *folio, sector_t block; sector_t last_block; struct buffer_head *bh, *head; - unsigned int blocksize, bbits; + size_t blocksize; int nr_underway = 0; blk_opf_t write_flags = wbc_to_write_flags(wbc); @@ -1826,10 +1813,9 @@ int __block_write_full_folio(struct inode *inode, struct folio *folio, bh = head; blocksize = bh->b_size; - bbits = block_size_bits(blocksize); - block = (sector_t)folio->index << (PAGE_SHIFT - bbits); - last_block = (i_size_read(inode) - 1) >> bbits; + block = div_u64(folio_pos(folio), blocksize); + last_block = div_u64(i_size_read(inode) - 1, blocksize); /* * Get all the dirty buffers mapped to disk addresses and @@ -2355,7 +2341,7 @@ int block_read_full_folio(struct folio *folio, get_block_t *get_block) struct inode *inode = folio->mapping->host; sector_t iblock, lblock; struct buffer_head *bh, *head, *arr[MAX_BUF_PER_PAGE]; - unsigned int blocksize, bbits; + size_t blocksize; int nr, i; int fully_mapped = 1; bool page_error = false; @@ -2369,10 +2355,9 @@ int block_read_full_folio(struct folio *folio, get_block_t *get_block) head = folio_create_buffers(folio, inode, 0); blocksize = head->b_size; - bbits = block_size_bits(blocksize); - iblock = (sector_t)folio->index << (PAGE_SHIFT - bbits); - lblock = (limit+blocksize-1) >> bbits; + iblock = div_u64(folio_pos(folio), blocksize); + lblock = div_u64(limit + blocksize - 1, blocksize); bh = head; nr = 0; i = 0; -- cgit v1.2.3