[PATCH 04/20] mm/migrate: Convert buffer_migrate_page() to buffer_migrate_folio()
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Date: 2022-06-06 20:47:54
Also in:
linux-block, linux-btrfs, linux-ext4, linux-f2fs-devel, linux-fsdevel, linux-mm, linux-nfs, linux-xfs, lkml, ocfs2-devel
Subsystem:
block layer, ext2 file system, ext4 file system, filesystems (vfs and infrastructure), memory management, memory management - memory policy and migration, ntfs filesystem, oracle cluster filesystem 2 (ocfs2), the rest · Maintainers:
Jens Axboe, Jan Kara, "Theodore Ts'o", Alexander Viro, Christian Brauner, Andrew Morton, David Hildenbrand, Namjae Jeon, Hyunchul Lee, Mark Fasheh, Joel Becker, Joseph Qi, Linus Torvalds
Use a folio throughout __buffer_migrate_folio(), add kernel-doc for buffer_migrate_folio() and buffer_migrate_folio_norefs(), move their declarations to buffer.h and switch all filesystems that have wired them up. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> --- block/fops.c | 2 +- fs/ext2/inode.c | 4 +- fs/ext4/inode.c | 4 +- fs/ntfs/aops.c | 6 +-- fs/ocfs2/aops.c | 2 +- include/linux/buffer_head.h | 10 +++++ include/linux/fs.h | 12 ------ mm/migrate.c | 76 ++++++++++++++++++++++--------------- 8 files changed, 65 insertions(+), 51 deletions(-)
diff --git a/block/fops.c b/block/fops.c
index d6b3276a6c68..743fc46d0aad 100644
--- a/block/fops.c
+++ b/block/fops.c@@ -417,7 +417,7 @@ const struct address_space_operations def_blk_aops = { .write_end = blkdev_write_end, .writepages = blkdev_writepages, .direct_IO = blkdev_direct_IO, - .migratepage = buffer_migrate_page_norefs, + .migrate_folio = buffer_migrate_folio_norefs, .is_dirty_writeback = buffer_check_dirty_writeback, };
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index 360ce3604a2d..84570c6265aa 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c@@ -973,7 +973,7 @@ const struct address_space_operations ext2_aops = { .bmap = ext2_bmap, .direct_IO = ext2_direct_IO, .writepages = ext2_writepages, - .migratepage = buffer_migrate_page, + .migrate_folio = buffer_migrate_folio, .is_partially_uptodate = block_is_partially_uptodate, .error_remove_page = generic_error_remove_page, };
@@ -989,7 +989,7 @@ const struct address_space_operations ext2_nobh_aops = { .bmap = ext2_bmap, .direct_IO = ext2_direct_IO, .writepages = ext2_writepages, - .migratepage = buffer_migrate_page, + .migrate_folio = buffer_migrate_folio, .error_remove_page = generic_error_remove_page, };
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 1aaea53e67b5..53877ffe3c41 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c@@ -3633,7 +3633,7 @@ static const struct address_space_operations ext4_aops = { .invalidate_folio = ext4_invalidate_folio, .release_folio = ext4_release_folio, .direct_IO = noop_direct_IO, - .migratepage = buffer_migrate_page, + .migrate_folio = buffer_migrate_folio, .is_partially_uptodate = block_is_partially_uptodate, .error_remove_page = generic_error_remove_page, .swap_activate = ext4_iomap_swap_activate,
@@ -3668,7 +3668,7 @@ static const struct address_space_operations ext4_da_aops = { .invalidate_folio = ext4_invalidate_folio, .release_folio = ext4_release_folio, .direct_IO = noop_direct_IO, - .migratepage = buffer_migrate_page, + .migrate_folio = buffer_migrate_folio, .is_partially_uptodate = block_is_partially_uptodate, .error_remove_page = generic_error_remove_page, .swap_activate = ext4_iomap_swap_activate,
diff --git a/fs/ntfs/aops.c b/fs/ntfs/aops.c
index 9e3964ea2ea0..5f4fb6ca6f2e 100644
--- a/fs/ntfs/aops.c
+++ b/fs/ntfs/aops.c@@ -1659,7 +1659,7 @@ const struct address_space_operations ntfs_normal_aops = { .dirty_folio = block_dirty_folio, #endif /* NTFS_RW */ .bmap = ntfs_bmap, - .migratepage = buffer_migrate_page, + .migrate_folio = buffer_migrate_folio, .is_partially_uptodate = block_is_partially_uptodate, .error_remove_page = generic_error_remove_page, };
@@ -1673,7 +1673,7 @@ const struct address_space_operations ntfs_compressed_aops = { .writepage = ntfs_writepage, .dirty_folio = block_dirty_folio, #endif /* NTFS_RW */ - .migratepage = buffer_migrate_page, + .migrate_folio = buffer_migrate_folio, .is_partially_uptodate = block_is_partially_uptodate, .error_remove_page = generic_error_remove_page, };
@@ -1688,7 +1688,7 @@ const struct address_space_operations ntfs_mst_aops = { .writepage = ntfs_writepage, /* Write dirty page to disk. */ .dirty_folio = filemap_dirty_folio, #endif /* NTFS_RW */ - .migratepage = buffer_migrate_page, + .migrate_folio = buffer_migrate_folio, .is_partially_uptodate = block_is_partially_uptodate, .error_remove_page = generic_error_remove_page, };
diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index 767df51f8657..1d489003f99d 100644
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c@@ -2462,7 +2462,7 @@ const struct address_space_operations ocfs2_aops = { .direct_IO = ocfs2_direct_IO, .invalidate_folio = block_invalidate_folio, .release_folio = ocfs2_release_folio, - .migratepage = buffer_migrate_page, + .migrate_folio = buffer_migrate_folio, .is_partially_uptodate = block_is_partially_uptodate, .error_remove_page = generic_error_remove_page, };
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index c9d1463bb20f..b0366c89d6a4 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h@@ -267,6 +267,16 @@ int nobh_truncate_page(struct address_space *, loff_t, get_block_t *); int nobh_writepage(struct page *page, get_block_t *get_block, struct writeback_control *wbc); +#ifdef CONFIG_MIGRATION +extern int buffer_migrate_folio(struct address_space *, + struct folio *dst, struct folio *src, enum migrate_mode); +extern int buffer_migrate_folio_norefs(struct address_space *, + struct folio *dst, struct folio *src, enum migrate_mode); +#else +#define buffer_migrate_folio NULL +#define buffer_migrate_folio_norefs NULL +#endif + void buffer_init(void); /*
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 7b380fa66983..5737c92ed286 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h@@ -3217,18 +3217,6 @@ extern int generic_check_addressable(unsigned, u64); extern void generic_set_encrypted_ci_d_ops(struct dentry *dentry); -#ifdef CONFIG_MIGRATION -extern int buffer_migrate_page(struct address_space *, - struct page *, struct page *, - enum migrate_mode); -extern int buffer_migrate_page_norefs(struct address_space *, - struct page *, struct page *, - enum migrate_mode); -#else -#define buffer_migrate_page NULL -#define buffer_migrate_page_norefs NULL -#endif - int may_setattr(struct user_namespace *mnt_userns, struct inode *inode, unsigned int ia_valid); int setattr_prepare(struct user_namespace *, struct dentry *, struct iattr *);
diff --git a/mm/migrate.c b/mm/migrate.c
index f19246c12fe9..77b8c662c9ca 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c@@ -657,23 +657,23 @@ static bool buffer_migrate_lock_buffers(struct buffer_head *head, return true; } -static int __buffer_migrate_page(struct address_space *mapping, - struct page *newpage, struct page *page, enum migrate_mode mode, +static int __buffer_migrate_folio(struct address_space *mapping, + struct folio *dst, struct folio *src, enum migrate_mode mode, bool check_refs) { struct buffer_head *bh, *head; int rc; int expected_count; - if (!page_has_buffers(page)) - return migrate_page(mapping, newpage, page, mode); + head = folio_buffers(src); + if (!head) + return migrate_page(mapping, &dst->page, &src->page, mode); /* Check whether page does not have extra refs before we do more work */ - expected_count = expected_page_refs(mapping, page); - if (page_count(page) != expected_count) + expected_count = expected_page_refs(mapping, &src->page); + if (folio_ref_count(src) != expected_count) return -EAGAIN; - head = page_buffers(page); if (!buffer_migrate_lock_buffers(head, mode)) return -EAGAIN;
@@ -704,23 +704,22 @@ static int __buffer_migrate_page(struct address_space *mapping, } } - rc = migrate_page_move_mapping(mapping, newpage, page, 0); + rc = folio_migrate_mapping(mapping, dst, src, 0); if (rc != MIGRATEPAGE_SUCCESS) goto unlock_buffers; - attach_page_private(newpage, detach_page_private(page)); + folio_attach_private(dst, folio_detach_private(src)); bh = head; do { - set_bh_page(bh, newpage, bh_offset(bh)); + set_bh_page(bh, &dst->page, bh_offset(bh)); bh = bh->b_this_page; - } while (bh != head); if (mode != MIGRATE_SYNC_NO_COPY) - migrate_page_copy(newpage, page); + folio_migrate_copy(dst, src); else - migrate_page_states(newpage, page); + folio_migrate_flags(dst, src); rc = MIGRATEPAGE_SUCCESS; unlock_buffers:
@@ -730,34 +729,51 @@ static int __buffer_migrate_page(struct address_space *mapping, do { unlock_buffer(bh); bh = bh->b_this_page; - } while (bh != head); return rc; } -/* - * Migration function for pages with buffers. This function can only be used - * if the underlying filesystem guarantees that no other references to "page" - * exist. For example attached buffer heads are accessed only under page lock. +/** + * buffer_migrate_folio() - Migration function for folios with buffers. + * @mapping: The address space containing @src. + * @dst: The folio to migrate to. + * @src: The folio to migrate from. + * @mode: How to migrate the folio. + * + * This function can only be used if the underlying filesystem guarantees + * that no other references to @src exist. For example attached buffer + * heads are accessed only under the folio lock. If your filesystem cannot + * provide this guarantee, buffer_migrate_folio_noref() may be more + * appropriate. + * + * Return: 0 on success or a negative errno on failure. */ -int buffer_migrate_page(struct address_space *mapping, - struct page *newpage, struct page *page, enum migrate_mode mode) +int buffer_migrate_folio(struct address_space *mapping, + struct folio *dst, struct folio *src, enum migrate_mode mode) { - return __buffer_migrate_page(mapping, newpage, page, mode, false); + return __buffer_migrate_folio(mapping, dst, src, mode, false); } -EXPORT_SYMBOL(buffer_migrate_page); +EXPORT_SYMBOL(buffer_migrate_folio); -/* - * Same as above except that this variant is more careful and checks that there - * are also no buffer head references. This function is the right one for - * mappings where buffer heads are directly looked up and referenced (such as - * block device mappings). +/** + * buffer_migrate_folio_noref() - Migration function for folios with buffers. + * @mapping: The address space containing @src. + * @dst: The folio to migrate to. + * @src: The folio to migrate from. + * @mode: How to migrate the folio. + * + * Like buffer_migrate_folio() except that this variant is more careful + * and checks that there are also no buffer head references. This function + * is the right one for mappings where buffer heads are directly looked + * up and referenced (such as block device mappings). + * + * Return: 0 on success or a negative errno on failure. */ -int buffer_migrate_page_norefs(struct address_space *mapping, - struct page *newpage, struct page *page, enum migrate_mode mode) +int buffer_migrate_folio_norefs(struct address_space *mapping, + struct folio *dst, struct folio *src, enum migrate_mode mode) { - return __buffer_migrate_page(mapping, newpage, page, mode, true); + return __buffer_migrate_folio(mapping, dst, src, mode, true); } #endif
--
2.35.1
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