fs: Introduce i_blocks_per_page

This helper is useful for both THPs and for supporting block size larger
than page size.  Convert all users that I could find (we have a few
different ways of writing this idiom, and I may have missed some).

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Acked-by: Dave Kleikamp <dave.kleikamp@oracle.com>

diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index d8013f38a317f52a8270bcb3c999ef764c895597..dd0739606dced72390ee99da36d8d6560a685018 100644 (file)
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -46,7 +46,7 @@ iomap_page_create(struct inode *inode, struct page *page)
 {
        struct iomap_page *iop = to_iomap_page(page);
 
-       if (iop || i_blocksize(inode) == PAGE_SIZE)
+       if (iop || i_blocks_per_page(inode, page) <= 1)
                return iop;
 
        iop = kmalloc(sizeof(*iop), GFP_NOFS | __GFP_NOFAIL);
@@ -147,7 +147,7 @@ iomap_iop_set_range_uptodate(struct page *page, unsigned off, unsigned len)
        unsigned int i;
 
        spin_lock_irqsave(&iop->uptodate_lock, flags);
-       for (i = 0; i < PAGE_SIZE / i_blocksize(inode); i++) {
+       for (i = 0; i < i_blocks_per_page(inode, page); i++) {
                if (i >= first && i <= last)
                        set_bit(i, iop->uptodate);
                else if (!test_bit(i, iop->uptodate))
@@ -1077,7 +1077,7 @@ iomap_finish_page_writeback(struct inode *inode, struct page *page,
                mapping_set_error(inode->i_mapping, -EIO);
        }
 
-       WARN_ON_ONCE(i_blocksize(inode) < PAGE_SIZE && !iop);
+       WARN_ON_ONCE(i_blocks_per_page(inode, page) > 1 && !iop);
        WARN_ON_ONCE(iop && atomic_read(&iop->write_count) <= 0);
 
        if (!iop || atomic_dec_and_test(&iop->write_count))
@@ -1373,7 +1373,7 @@ iomap_writepage_map(struct iomap_writepage_ctx *wpc,
        int error = 0, count = 0, i;
        LIST_HEAD(submit_list);
 
-       WARN_ON_ONCE(i_blocksize(inode) < PAGE_SIZE && !iop);
+       WARN_ON_ONCE(i_blocks_per_page(inode, page) > 1 && !iop);
        WARN_ON_ONCE(iop && atomic_read(&iop->write_count) != 0);
 
        /*

diff --git a/fs/jfs/jfs_metapage.c b/fs/jfs/jfs_metapage.c
index a2f5338a5ea188808c1dd6635f95b1c155ffbffd..176580f54af96160a12447f2893223abd2bac4d0 100644 (file)
--- a/fs/jfs/jfs_metapage.c
+++ b/fs/jfs/jfs_metapage.c
@@ -473,7 +473,7 @@ static int metapage_readpage(struct file *fp, struct page *page)
        struct inode *inode = page->mapping->host;
        struct bio *bio = NULL;
        int block_offset;
-       int blocks_per_page = PAGE_SIZE >> inode->i_blkbits;
+       int blocks_per_page = i_blocks_per_page(inode, page);
        sector_t page_start;    /* address of page in fs blocks */
        sector_t pblock;
        int xlen;

diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index b35611882ff9c565d740c8b80e17633a0096a41e..55d126d4e096e2e32a1dade11e271deb21078f11 100644 (file)
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -544,7 +544,7 @@ xfs_discard_page(
                        page, ip->i_ino, offset);
 
        error = xfs_bmap_punch_delalloc_range(ip, start_fsb,
-                       PAGE_SIZE / i_blocksize(inode));
+                       i_blocks_per_page(inode, page));
        if (error && !XFS_FORCED_SHUTDOWN(mp))
                xfs_alert(mp, "page discard unable to remove delalloc mapping.");
 out_invalidate:

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 7de11dcd534d6fdb171c382bf14e896ca0e6b5c3..85373328613820ab19bc0e2a8661b406c6cdd010 100644 (file)
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -899,4 +899,20 @@ static inline int page_mkwrite_check_truncate(struct page *page,
        return offset;
 }
 
+/**
+ * i_blocks_per_page - How many blocks fit in this page.
+ * @inode: The inode which contains the blocks.
+ * @page: The page (head page if the page is a THP).
+ *
+ * If the block size is larger than the size of this page, return zero.
+ *
+ * Context: The caller should hold a refcount on the page to prevent it
+ * from being split.
+ * Return: The number of filesystem blocks covered by this page.
+ */
+static inline
+unsigned int i_blocks_per_page(struct inode *inode, struct page *page)
+{
+       return thp_size(page) >> inode->i_blkbits;
+}
 #endif /* _LINUX_PAGEMAP_H */