iomap: build the writeback code without CONFIG_BLOCK

Allow fuse to use the iomap writeback code even when CONFIG_BLOCK is
not enabled.  Do this with an ifdef instead of a separate file to keep
the iomap_folio_state local to buffered-io.c.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/20250710133343.399917-15-hch@lst.de
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/fs/iomap/Makefile b/fs/iomap/Makefile
index 69e8ebb41302a703de9a57dbee5bf4d9c702f0ce..f7e1c8534c4641c2e66ed66a91b9e20935b004aa 100644 (file)
--- a/fs/iomap/Makefile
+++ b/fs/iomap/Makefile
@@ -9,9 +9,9 @@ ccflags-y += -I $(src)          # needed for trace events
 obj-$(CONFIG_FS_IOMAP)         += iomap.o
 
 iomap-y                                += trace.o \
-                                  iter.o
-iomap-$(CONFIG_BLOCK)          += buffered-io.o \
-                                  direct-io.o \
+                                  iter.o \
+                                  buffered-io.o
+iomap-$(CONFIG_BLOCK)          += direct-io.o \
                                   ioend.o \
                                   fiemap.o \
                                   seek.o

diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index aed4fc30a8490f7e2da6601c800d0413e17634b8..bcc6e0e5334eb98cba9fa6827639b735ef335480 100644 (file)
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -275,6 +275,46 @@ static void iomap_adjust_read_range(struct inode *inode, struct folio *folio,
        *lenp = plen;
 }
 
+static inline bool iomap_block_needs_zeroing(const struct iomap_iter *iter,
+               loff_t pos)
+{
+       const struct iomap *srcmap = iomap_iter_srcmap(iter);
+
+       return srcmap->type != IOMAP_MAPPED ||
+               (srcmap->flags & IOMAP_F_NEW) ||
+               pos >= i_size_read(iter->inode);
+}
+
+/**
+ * iomap_read_inline_data - copy inline data into the page cache
+ * @iter: iteration structure
+ * @folio: folio to copy to
+ *
+ * Copy the inline data in @iter into @folio and zero out the rest of the folio.
+ * Only a single IOMAP_INLINE extent is allowed at the end of each file.
+ * Returns zero for success to complete the read, or the usual negative errno.
+ */
+static int iomap_read_inline_data(const struct iomap_iter *iter,
+               struct folio *folio)
+{
+       const struct iomap *iomap = iomap_iter_srcmap(iter);
+       size_t size = i_size_read(iter->inode) - iomap->offset;
+       size_t offset = offset_in_folio(folio, iomap->offset);
+
+       if (folio_test_uptodate(folio))
+               return 0;
+
+       if (WARN_ON_ONCE(size > iomap->length))
+               return -EIO;
+       if (offset > 0)
+               ifs_alloc(iter->inode, folio, iter->flags);
+
+       folio_fill_tail(folio, offset, iomap->inline_data, size);
+       iomap_set_range_uptodate(folio, offset, folio_size(folio) - offset);
+       return 0;
+}
+
+#ifdef CONFIG_BLOCK
 static void iomap_finish_folio_read(struct folio *folio, size_t off,
                size_t len, int error)
 {
@@ -314,45 +354,6 @@ struct iomap_readpage_ctx {
        struct readahead_control *rac;
 };
 
-/**
- * iomap_read_inline_data - copy inline data into the page cache
- * @iter: iteration structure
- * @folio: folio to copy to
- *
- * Copy the inline data in @iter into @folio and zero out the rest of the folio.
- * Only a single IOMAP_INLINE extent is allowed at the end of each file.
- * Returns zero for success to complete the read, or the usual negative errno.
- */
-static int iomap_read_inline_data(const struct iomap_iter *iter,
-               struct folio *folio)
-{
-       const struct iomap *iomap = iomap_iter_srcmap(iter);
-       size_t size = i_size_read(iter->inode) - iomap->offset;
-       size_t offset = offset_in_folio(folio, iomap->offset);
-
-       if (folio_test_uptodate(folio))
-               return 0;
-
-       if (WARN_ON_ONCE(size > iomap->length))
-               return -EIO;
-       if (offset > 0)
-               ifs_alloc(iter->inode, folio, iter->flags);
-
-       folio_fill_tail(folio, offset, iomap->inline_data, size);
-       iomap_set_range_uptodate(folio, offset, folio_size(folio) - offset);
-       return 0;
-}
-
-static inline bool iomap_block_needs_zeroing(const struct iomap_iter *iter,
-               loff_t pos)
-{
-       const struct iomap *srcmap = iomap_iter_srcmap(iter);
-
-       return srcmap->type != IOMAP_MAPPED ||
-               (srcmap->flags & IOMAP_F_NEW) ||
-               pos >= i_size_read(iter->inode);
-}
-
 static int iomap_readpage_iter(struct iomap_iter *iter,
                struct iomap_readpage_ctx *ctx)
 {
@@ -545,6 +546,27 @@ void iomap_readahead(struct readahead_control *rac, const struct iomap_ops *ops)
 }
 EXPORT_SYMBOL_GPL(iomap_readahead);
 
+static int iomap_read_folio_range(const struct iomap_iter *iter,
+               struct folio *folio, loff_t pos, size_t len)
+{
+       const struct iomap *srcmap = iomap_iter_srcmap(iter);
+       struct bio_vec bvec;
+       struct bio bio;
+
+       bio_init(&bio, srcmap->bdev, &bvec, 1, REQ_OP_READ);
+       bio.bi_iter.bi_sector = iomap_sector(srcmap, pos);
+       bio_add_folio_nofail(&bio, folio, len, offset_in_folio(folio, pos));
+       return submit_bio_wait(&bio);
+}
+#else
+static int iomap_read_folio_range(const struct iomap_iter *iter,
+               struct folio *folio, loff_t pos, size_t len)
+{
+       WARN_ON_ONCE(1);
+       return -EIO;
+}
+#endif /* CONFIG_BLOCK */
+
 /*
  * iomap_is_partially_uptodate checks whether blocks within a folio are
  * uptodate or not.
@@ -658,19 +680,6 @@ iomap_write_failed(struct inode *inode, loff_t pos, unsigned len)
                                         pos + len - 1);
 }
 
-static int iomap_read_folio_range(const struct iomap_iter *iter,
-               struct folio *folio, loff_t pos, size_t len)
-{
-       const struct iomap *srcmap = iomap_iter_srcmap(iter);
-       struct bio_vec bvec;
-       struct bio bio;
-
-       bio_init(&bio, srcmap->bdev, &bvec, 1, REQ_OP_READ);
-       bio.bi_iter.bi_sector = iomap_sector(srcmap, pos);
-       bio_add_folio_nofail(&bio, folio, len, offset_in_folio(folio, pos));
-       return submit_bio_wait(&bio);
-}
-
 static int __iomap_write_begin(const struct iomap_iter *iter,
                const struct iomap_write_ops *write_ops, size_t len,
                struct folio *folio)