[syzbot ci] Re: minix: convert to iomap and add direct I/O

[Jeremy Bingham <jbingham@gmail.com>]

Apparently I did this wrong the first time. I misunderstood and sent one
patch covering all the changes differing from master, rather than just
patching the changes to fix the errors syzbot found.

#syz test

---
 fs/minix/file.c         |  4 ++--
 fs/minix/inode.c        | 11 ++++++-----
 fs/minix/itree_common.c | 11 ++++++++++-
 fs/minix/minix.h        |  3 +++
 4 files changed, 21 insertions(+), 8 deletions(-)

diff --git a/fs/minix/file.c b/fs/minix/file.c
index 1f4217115401..b07c853fa43a 100644
--- a/fs/minix/file.c
+++ b/fs/minix/file.c
@@ -175,8 +175,8 @@ const struct file_operations minix_file_operations = {
 	.splice_write	= iter_file_splice_write,
 };
 
-static int minix_setattr(struct mnt_idmap *idmap,
-			 struct dentry *dentry, struct iattr *attr)
+int minix_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
+	struct iattr *attr)
 {
 	struct inode *inode = d_inode(dentry);
 	int error;
diff --git a/fs/minix/inode.c b/fs/minix/inode.c
index cd12e59ce9b9..8a79ff82a656 100644
--- a/fs/minix/inode.c
+++ b/fs/minix/inode.c
@@ -444,10 +444,10 @@ static ssize_t minix_writeback_range(struct iomap_writepage_ctx *wpc,
 	if (pos < wpc->iomap.offset ||
 			pos >= wpc->iomap.offset + wpc->iomap.length) {
 		if (INODE_VERSION(wpc->inode) == MINIX_V1)
-			error = V1_minix_iomap_begin(wpc->inode, pos, len, 0,
+			error = V1_minix_iomap_begin(wpc->inode, pos, len, IOMAP_WRITE,
 				&wpc->iomap, NULL);
 		else
-			error = V2_minix_iomap_begin(wpc->inode, pos, len, 0,
+			error = V2_minix_iomap_begin(wpc->inode, pos, len, IOMAP_WRITE,
 				&wpc->iomap, NULL);
 		if (error)
 			return error;
@@ -490,7 +490,7 @@ static int minix_writepages(struct address_space *mapping,
 
 static int minix_read_folio(struct file *file, struct folio *folio)
 {
-	const struct iomap_ops *ops = minix_iomap_ops_ver(file->f_inode);
+	const struct iomap_ops *ops = minix_iomap_ops_ver(folio->mapping->host);
 
 	iomap_bio_read_folio(folio, ops);
 	return 0;
@@ -504,7 +504,7 @@ static int minix_block_read_folio(struct file *file, struct folio *folio)
 
 static void minix_readahead(struct readahead_control *rac)
 {
-	const struct iomap_ops *ops = minix_iomap_ops_ver(rac->file->f_inode);
+	const struct iomap_ops *ops = minix_iomap_ops_ver(rac->mapping->host);
 
 	iomap_bio_readahead(rac, ops);
 }
@@ -545,7 +545,7 @@ static sector_t minix_bmap(struct address_space *mapping, sector_t block)
 	return iomap_bmap(mapping, block, ops);
 }
 
-static const struct address_space_operations minix_aops = {
+const struct address_space_operations minix_aops = {
 	.dirty_folio	= iomap_dirty_folio,
 	.invalidate_folio = iomap_invalidate_folio,
 	.read_folio = minix_read_folio,
@@ -575,6 +575,7 @@ static const struct address_space_operations minix_dir_aops = {
 static const struct inode_operations minix_symlink_inode_operations = {
 	.get_link	= page_get_link,
 	.getattr	= minix_getattr,
+	.setattr	= minix_setattr,
 };
 
 void minix_set_inode(struct inode *inode, dev_t rdev)
diff --git a/fs/minix/itree_common.c b/fs/minix/itree_common.c
index c3cd2c75af9c..5a8b73a7beda 100644
--- a/fs/minix/itree_common.c
+++ b/fs/minix/itree_common.c
@@ -311,7 +311,16 @@ static inline void truncate (struct inode * inode)
 	long iblock;
 
 	iblock = (inode->i_size + sb->s_blocksize -1) >> sb->s_blocksize_bits;
-	block_truncate_page(inode->i_mapping, inode->i_size, get_block);
+
+	/* Depending on what address space operations are being used by the
+	 * inode being truncated, we need to either call iomap_truncate_page or
+	 * block_truncate_page.
+	 */
+	if (inode->i_mapping->a_ops == &minix_aops)
+		iomap_truncate_page(inode, inode->i_size, NULL,
+			minix_iomap_ops_ver(inode), NULL, NULL);
+	else
+		block_truncate_page(inode->i_mapping, inode->i_size, get_block);
 
 	n = block_to_path(inode, iblock, offsets);
 	if (!n)
diff --git a/fs/minix/minix.h b/fs/minix/minix.h
index face74100346..270e4e0620a1 100644
--- a/fs/minix/minix.h
+++ b/fs/minix/minix.h
@@ -58,6 +58,8 @@ void minix_free_block(struct inode *inode, unsigned long block);
 unsigned long minix_count_free_blocks(struct super_block *sb);
 int minix_getattr(struct mnt_idmap *, const struct path *,
 		struct kstat *, u32, unsigned);
+int minix_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
+	struct iattr *attr);
 int minix_prepare_chunk(struct folio *folio, loff_t pos, unsigned len);
 struct mapping_metadata_bhs *minix_get_metadata_bhs(struct inode *inode);
 int minix_fsync(struct file *file, loff_t start, loff_t end, int datasync);
@@ -88,6 +90,7 @@ extern int V2_minix_iomap_begin(struct inode *inode, loff_t offset,
 	loff_t length, unsigned int flags, struct iomap *iomap,
 	struct iomap *srcmap);
 
+extern const struct address_space_operations minix_aops;
 extern const struct inode_operations minix_file_inode_operations;
 extern const struct inode_operations minix_dir_inode_operations;
 extern const struct file_operations minix_file_operations;
-- 
2.47.3