ext4: convert move_extent_per_page() to use folios

Patch series "Removing the try_to_release_page() wrapper", v3.

This patchset replaces the remaining calls of try_to_release_page() with
the folio equivalent: filemap_release_folio().  This allows us to remove
the wrapper.

This patch (of 4):

Convert move_extent_per_page() to use folios.  This change removes 5 calls
to compound_head() and is in preparation for the removal of the
try_to_release_page() wrapper.

Link: https://lkml.kernel.org/r/20221118073055.55694-1-vishal.moola@gmail.com
Link: https://lkml.kernel.org/r/20221118073055.55694-2-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c
index 044e34c..8dbb87e 100644 (file)
--- a/fs/ext4/move_extent.c
+++ b/fs/ext4/move_extent.c
@@ -253,6 +253,7 @@ move_extent_per_page(struct file *o_filp, struct inode *donor_inode,
 {
        struct inode *orig_inode = file_inode(o_filp);
        struct page *pagep[2] = {NULL, NULL};
+       struct folio *folio[2] = {NULL, NULL};
        handle_t *handle;
        ext4_lblk_t orig_blk_offset, donor_blk_offset;
        unsigned long blocksize = orig_inode->i_sb->s_blocksize;
@@ -313,6 +314,13 @@ again:
         * hold page's lock, if it is still the case data copy is not
         * necessary, just swap data blocks between orig and donor.
         */
+       folio[0] = page_folio(pagep[0]);
+       folio[1] = page_folio(pagep[1]);
+
+       VM_BUG_ON_FOLIO(folio_test_large(folio[0]), folio[0]);
+       VM_BUG_ON_FOLIO(folio_test_large(folio[1]), folio[1]);
+       VM_BUG_ON_FOLIO(folio_nr_pages(folio[0]) != folio_nr_pages(folio[1]), folio[1]);
+
        if (unwritten) {
                ext4_double_down_write_data_sem(orig_inode, donor_inode);
                /* If any of extents in range became initialized we have to
@@ -331,10 +339,10 @@ again:
                        ext4_double_up_write_data_sem(orig_inode, donor_inode);
                        goto data_copy;
                }
-               if ((page_has_private(pagep[0]) &&
-                    !try_to_release_page(pagep[0], 0)) ||
-                   (page_has_private(pagep[1]) &&
-                    !try_to_release_page(pagep[1], 0))) {
+               if ((folio_has_private(folio[0]) &&
+                    !filemap_release_folio(folio[0], 0)) ||
+                   (folio_has_private(folio[1]) &&
+                    !filemap_release_folio(folio[1], 0))) {
                        *err = -EBUSY;
                        goto drop_data_sem;
                }
@@ -344,19 +352,21 @@ again:
                                                   block_len_in_page, 1, err);
        drop_data_sem:
                ext4_double_up_write_data_sem(orig_inode, donor_inode);
-               goto unlock_pages;
+               goto unlock_folios;
        }
 data_copy:
-       *err = mext_page_mkuptodate(pagep[0], from, from + replaced_size);
+       *err = mext_page_mkuptodate(&folio[0]->page, from, from + replaced_size);
        if (*err)
-               goto unlock_pages;
+               goto unlock_folios;
 
        /* At this point all buffers in range are uptodate, old mapping layout
         * is no longer required, try to drop it now. */
-       if ((page_has_private(pagep[0]) && !try_to_release_page(pagep[0], 0)) ||
-           (page_has_private(pagep[1]) && !try_to_release_page(pagep[1], 0))) {
+       if ((folio_has_private(folio[0]) &&
+               !filemap_release_folio(folio[0], 0)) ||
+           (folio_has_private(folio[1]) &&
+               !filemap_release_folio(folio[1], 0))) {
                *err = -EBUSY;
-               goto unlock_pages;
+               goto unlock_folios;
        }
        ext4_double_down_write_data_sem(orig_inode, donor_inode);
        replaced_count = ext4_swap_extents(handle, orig_inode, donor_inode,
@@ -369,13 +379,13 @@ data_copy:
                        replaced_size =
                                block_len_in_page << orig_inode->i_blkbits;
                } else
-                       goto unlock_pages;
+                       goto unlock_folios;
        }
        /* Perform all necessary steps similar write_begin()/write_end()
         * but keeping in mind that i_size will not change */
-       if (!page_has_buffers(pagep[0]))
-               create_empty_buffers(pagep[0], 1 << orig_inode->i_blkbits, 0);
-       bh = page_buffers(pagep[0]);
+       if (!folio_buffers(folio[0]))
+               create_empty_buffers(&folio[0]->page, 1 << orig_inode->i_blkbits, 0);
+       bh = folio_buffers(folio[0]);
        for (i = 0; i < data_offset_in_page; i++)
                bh = bh->b_this_page;
        for (i = 0; i < block_len_in_page; i++) {
@@ -385,7 +395,7 @@ data_copy:
                bh = bh->b_this_page;
        }
        if (!*err)
-               *err = block_commit_write(pagep[0], from, from + replaced_size);
+               *err = block_commit_write(&folio[0]->page, from, from + replaced_size);
 
        if (unlikely(*err < 0))
                goto repair_branches;
@@ -395,11 +405,11 @@ data_copy:
        *err = ext4_jbd2_inode_add_write(handle, orig_inode,
                        (loff_t)orig_page_offset << PAGE_SHIFT, replaced_size);
 
-unlock_pages:
-       unlock_page(pagep[0]);
-       put_page(pagep[0]);
-       unlock_page(pagep[1]);
-       put_page(pagep[1]);
+unlock_folios:
+       folio_unlock(folio[0]);
+       folio_put(folio[0]);
+       folio_unlock(folio[1]);
+       folio_put(folio[1]);
 stop_journal:
        ext4_journal_stop(handle);
        if (*err == -ENOSPC &&
@@ -430,7 +440,7 @@ repair_branches:
                *err = -EIO;
        }
        replaced_count = 0;
-       goto unlock_pages;
+       goto unlock_folios;
 }
 
 /**