ext4: support large block size in mpage_prepare_extent_to_map()

Use the EXT4_PG_TO_LBLK/EXT4_LBLK_TO_PG macros to complete the conversion
between folio indexes and blocks to avoid negative left/right shifts after
supporting blocksize greater than PAGE_SIZE.

Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Message-ID: <20251121090654.631996-20-libaokun@huaweicloud.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 847770f57bfc187e0599a40b96faacf214a87d8d..8cf33a58d1a6c82e806f4e85b49c9bacb9974754 100644 (file)
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -2620,7 +2620,6 @@ static int mpage_prepare_extent_to_map(struct mpage_da_data *mpd)
        pgoff_t end = mpd->end_pos >> PAGE_SHIFT;
        xa_mark_t tag;
        int i, err = 0;
-       int blkbits = mpd->inode->i_blkbits;
        ext4_lblk_t lblk;
        struct buffer_head *head;
        handle_t *handle = NULL;
@@ -2659,7 +2658,7 @@ static int mpage_prepare_extent_to_map(struct mpage_da_data *mpd)
                         */
                        if (mpd->wbc->sync_mode == WB_SYNC_NONE &&
                            mpd->wbc->nr_to_write <=
-                           mpd->map.m_len >> (PAGE_SHIFT - blkbits))
+                           EXT4_LBLK_TO_PG(mpd->inode, mpd->map.m_len))
                                goto out;
 
                        /* If we can't merge this page, we are done. */
@@ -2737,8 +2736,7 @@ static int mpage_prepare_extent_to_map(struct mpage_da_data *mpd)
                                mpage_folio_done(mpd, folio);
                        } else {
                                /* Add all dirty buffers to mpd */
-                               lblk = ((ext4_lblk_t)folio->index) <<
-                                       (PAGE_SHIFT - blkbits);
+                               lblk = EXT4_PG_TO_LBLK(mpd->inode, folio->index);
                                head = folio_buffers(folio);
                                err = mpage_process_page_bufs(mpd, head, head,
                                                lblk);