[PATCH 05/20] fs: Introduce fiemap_ctx data structure

[Carlos Maiolino <cmaiolino@redhat.com>]

As the overall goal to deprecate fibmap, Christoph suggested a rework of
the ->fiemap API, in a way we could pass to it a callback to fill the
fiemap structure (one of these callbacks being fiemap_fill_next_extent).

To avoid the need to add several fields into the ->fiemap method, just
aggregate everything into a single data structure, and pass it along.

This patch isn't suppose to add any functional change, only to update
filesystems providing ->fiemap() method.

Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
---
 fs/bad_inode.c        |  4 +---
 fs/btrfs/inode.c      |  6 ++++--
 fs/ext2/ext2.h        |  3 +--
 fs/ext2/inode.c       |  6 ++----
 fs/ext4/ext4.h        |  3 +--
 fs/ext4/extents.c     |  9 +++++----
 fs/f2fs/data.c        |  6 ++++--
 fs/f2fs/f2fs.h        |  3 +--
 fs/gfs2/inode.c       |  6 ++++--
 fs/hpfs/file.c        |  4 ++--
 fs/ioctl.c            | 23 +++++++++++++++--------
 fs/nilfs2/inode.c     |  6 ++++--
 fs/nilfs2/nilfs.h     |  3 +--
 fs/ocfs2/extent_map.c |  6 ++++--
 fs/ocfs2/extent_map.h |  3 +--
 fs/overlayfs/inode.c  |  6 +++---
 fs/xfs/xfs_iops.c     |  9 +++++----
 include/linux/fs.h    | 27 +++++++++++++++++++--------
 18 files changed, 77 insertions(+), 56 deletions(-)

diff --git a/fs/bad_inode.c b/fs/bad_inode.c
index 8035d2a44561..b5fbe28b8d17 100644
--- a/fs/bad_inode.c
+++ b/fs/bad_inode.c
@@ -119,9 +119,7 @@ static struct posix_acl *bad_inode_get_acl(struct inode *inode, int type)
 	return ERR_PTR(-EIO);
 }
 
-static int bad_inode_fiemap(struct inode *inode,
-			    struct fiemap_extent_info *fieinfo, u64 start,
-			    u64 len)
+static int bad_inode_fiemap(struct inode *inode, struct fiemap_ctx *f_ctx)
 {
 	return -EIO;
 }
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index cd247a21afc4..ebe5aae69c44 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -8612,9 +8612,11 @@ static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
 
 #define BTRFS_FIEMAP_FLAGS	(FIEMAP_FLAG_SYNC)
 
-static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
-		__u64 start, __u64 len)
+static int btrfs_fiemap(struct inode *inode, struct fiemap_ctx *f_ctx)
 {
+	struct fiemap_extent_info *fieinfo = f_ctx->fc_data;
+	u64 start = f_ctx->fc_start;
+	u64 len	  = f_ctx->fc_len;
 	int	ret;
 
 	ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h
index e770cd100a6a..dc5dec52a7c8 100644
--- a/fs/ext2/ext2.h
+++ b/fs/ext2/ext2.h
@@ -775,8 +775,7 @@ extern void ext2_evict_inode(struct inode *);
 extern int ext2_get_block(struct inode *, sector_t, struct buffer_head *, int);
 extern int ext2_setattr (struct dentry *, struct iattr *);
 extern void ext2_set_inode_flags(struct inode *inode);
-extern int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
-		       u64 start, u64 len);
+extern int ext2_fiemap(struct inode *inode, struct fiemap_ctx *f_ctx);
 
 /* ioctl.c */
 extern long ext2_ioctl(struct file *, unsigned int, unsigned long);
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index e4bb9386c045..85e7edad58a3 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -855,11 +855,9 @@ const struct iomap_ops ext2_iomap_ops = {
 const struct iomap_ops ext2_iomap_ops;
 #endif /* CONFIG_FS_DAX */
 
-int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
-		u64 start, u64 len)
+int ext2_fiemap(struct inode *inode, struct fiemap_ctx *f_ctx)
 {
-	return generic_block_fiemap(inode, fieinfo, start, len,
-				    ext2_get_block);
+	return generic_block_fiemap(inode, f_ctx, ext2_get_block);
 }
 
 static int ext2_writepage(struct page *page, struct writeback_control *wbc)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 3f89d0ab08fc..acc1ea0e9f40 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -3140,8 +3140,7 @@ extern struct ext4_ext_path *ext4_find_extent(struct inode *, ext4_lblk_t,
 extern void ext4_ext_drop_refs(struct ext4_ext_path *);
 extern int ext4_ext_check_inode(struct inode *inode);
 extern ext4_lblk_t ext4_ext_next_allocated_block(struct ext4_ext_path *path);
-extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
-			__u64 start, __u64 len);
+extern int ext4_fiemap(struct inode *inode, struct fiemap_ctx *f_ctx);
 extern int ext4_ext_precache(struct inode *inode);
 extern int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len);
 extern int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len);
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 240b6dea5441..beccae768dac 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -5045,9 +5045,11 @@ static int ext4_xattr_fiemap(struct inode *inode,
 	return (error < 0 ? error : 0);
 }
 
-int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
-		__u64 start, __u64 len)
+int ext4_fiemap(struct inode *inode, struct fiemap_ctx *f_ctx)
 {
+	struct fiemap_extent_info *fieinfo = f_ctx->fc_data;
+	u64 start = f_ctx->fc_start;
+	u64 len = f_ctx->fc_len;
 	ext4_lblk_t start_blk;
 	int error = 0;
 
@@ -5069,8 +5071,7 @@ int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 
 	/* fallback to generic here if not in extents fmt */
 	if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
-		return generic_block_fiemap(inode, fieinfo, start, len,
-			ext4_get_block);
+		return generic_block_fiemap(inode, f_ctx, ext4_get_block);
 
 	if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS))
 		return -EBADR;
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 82b6e27a21cc..0f57403feb92 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1397,9 +1397,11 @@ static int f2fs_xattr_fiemap(struct inode *inode,
 	return (err < 0 ? err : 0);
 }
 
-int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
-		u64 start, u64 len)
+int f2fs_fiemap(struct inode *inode, struct fiemap_ctx *f_ctx)
 {
+	struct fiemap_extent_info *fieinfo = f_ctx->fc_data;
+	u64 start = f_ctx->fc_start;
+	u64 len = f_ctx->fc_len;
 	struct buffer_head map_bh;
 	sector_t start_blk, last_blk;
 	pgoff_t next_pgofs;
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 4175445be2b0..185bb39dd82c 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -3075,8 +3075,7 @@ int f2fs_do_write_data_page(struct f2fs_io_info *fio);
 void __do_map_lock(struct f2fs_sb_info *sbi, int flag, bool lock);
 int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
 			int create, int flag);
-int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
-			u64 start, u64 len);
+int f2fs_fiemap(struct inode *inode, struct fiemap_ctx *f_ctx);
 bool f2fs_should_update_inplace(struct inode *inode, struct f2fs_io_info *fio);
 bool f2fs_should_update_outplace(struct inode *inode, struct f2fs_io_info *fio);
 void f2fs_invalidate_page(struct page *page, unsigned int offset,
diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index 648f0ca1ad57..2a4ce713c209 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -2004,9 +2004,11 @@ static int gfs2_getattr(const struct path *path, struct kstat *stat,
 	return 0;
 }
 
-static int gfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
-		       u64 start, u64 len)
+static int gfs2_fiemap(struct inode *inode, struct fiemap_ctx *f_ctx)
 {
+	struct fiemap_extent_info *fieinfo = f_ctx->fc_data;
+	u64 start = f_ctx->fc_start;
+	u64 len = f_ctx->fc_len;
 	struct gfs2_inode *ip = GFS2_I(inode);
 	struct gfs2_holder gh;
 	int ret;
diff --git a/fs/hpfs/file.c b/fs/hpfs/file.c
index 1ecec124e76f..9e31278cbfe1 100644
--- a/fs/hpfs/file.c
+++ b/fs/hpfs/file.c
@@ -190,9 +190,9 @@ static sector_t _hpfs_bmap(struct address_space *mapping, sector_t block)
 	return generic_block_bmap(mapping, block, hpfs_get_block);
 }
 
-static int hpfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, u64 start, u64 len)
+static int hpfs_fiemap(struct inode *inode, struct fiemap_ctx *f_ctx)
 {
-	return generic_block_fiemap(inode, fieinfo, start, len, hpfs_get_block);
+	return generic_block_fiemap(inode, f_ctx, hpfs_get_block);
 }
 
 const struct address_space_operations hpfs_aops = {
diff --git a/fs/ioctl.c b/fs/ioctl.c
index 2005529af560..ddcc4f9a9cf1 100644
--- a/fs/ioctl.c
+++ b/fs/ioctl.c
@@ -181,6 +181,7 @@ static int ioctl_fiemap(struct file *filp, unsigned long arg)
 	struct fiemap_extent_info fieinfo = { 0, };
 	struct inode *inode = file_inode(filp);
 	struct super_block *sb = inode->i_sb;
+	struct fiemap_ctx f_ctx;
 	u64 len;
 	int error;
 
@@ -210,7 +211,12 @@ static int ioctl_fiemap(struct file *filp, unsigned long arg)
 	if (fieinfo.fi_flags & FIEMAP_FLAG_SYNC)
 		filemap_write_and_wait(inode->i_mapping);
 
-	error = inode->i_op->fiemap(inode, &fieinfo, fiemap.fm_start, len);
+	f_ctx.fc_flags = fieinfo.fi_flags;
+	f_ctx.fc_data = &fieinfo;
+	f_ctx.fc_start = fiemap.fm_start;
+	f_ctx.fc_len = len;
+
+	error = inode->i_op->fiemap(inode, &f_ctx);
 	fiemap.fm_flags = fieinfo.fi_flags;
 	fiemap.fm_mapped_extents = fieinfo.fi_extents_mapped;
 	if (copy_to_user(ufiemap, &fiemap, sizeof(fiemap)))
@@ -278,10 +284,12 @@ static inline loff_t blk_to_logical(struct inode *inode, sector_t blk)
  * generic_block_fiemap if you want the locking done for you.
  */
 
-int __generic_block_fiemap(struct inode *inode,
-			   struct fiemap_extent_info *fieinfo, loff_t start,
-			   loff_t len, get_block_t *get_block)
+int __generic_block_fiemap(struct inode *inode, struct fiemap_ctx *f_ctx,
+			   get_block_t *get_block)
 {
+	struct fiemap_extent_info *fieinfo = f_ctx->fc_data;
+	loff_t start = f_ctx->fc_start;
+	loff_t len = f_ctx->fc_len;
 	struct buffer_head map_bh;
 	sector_t start_blk, last_blk;
 	loff_t isize = i_size_read(inode);
@@ -437,13 +445,12 @@ EXPORT_SYMBOL(__generic_block_fiemap);
  * the inode's mutex lock.
  */
 
-int generic_block_fiemap(struct inode *inode,
-			 struct fiemap_extent_info *fieinfo, u64 start,
-			 u64 len, get_block_t *get_block)
+int generic_block_fiemap(struct inode *inode, struct fiemap_ctx *f_ctx,
+			 get_block_t *get_block)
 {
 	int ret;
 	inode_lock(inode);
-	ret = __generic_block_fiemap(inode, fieinfo, start, len, get_block);
+	ret = __generic_block_fiemap(inode, f_ctx, get_block);
 	inode_unlock(inode);
 	return ret;
 }
diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c
index 671085512e0f..529262f0ab7d 100644
--- a/fs/nilfs2/inode.c
+++ b/fs/nilfs2/inode.c
@@ -992,9 +992,11 @@ void nilfs_dirty_inode(struct inode *inode, int flags)
 	nilfs_transaction_commit(inode->i_sb); /* never fails */
 }
 
-int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
-		 __u64 start, __u64 len)
+int nilfs_fiemap(struct inode *inode, struct fiemap_ctx *f_ctx)
 {
+	struct fiemap_extent_info *fieinfo = f_ctx->fc_data;
+	u64 start = f_ctx->fc_start;
+	u64 len = f_ctx->fc_len;
 	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 	__u64 logical = 0, phys = 0, size = 0;
 	__u32 flags = 0;
diff --git a/fs/nilfs2/nilfs.h b/fs/nilfs2/nilfs.h
index a2f247b6a209..b403dae8c258 100644
--- a/fs/nilfs2/nilfs.h
+++ b/fs/nilfs2/nilfs.h
@@ -276,8 +276,7 @@ extern int nilfs_inode_dirty(struct inode *);
 int nilfs_set_file_dirty(struct inode *inode, unsigned int nr_dirty);
 extern int __nilfs_mark_inode_dirty(struct inode *, int);
 extern void nilfs_dirty_inode(struct inode *, int flags);
-int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
-		 __u64 start, __u64 len);
+int nilfs_fiemap(struct inode *inode, struct fiemap_ctx *f_ctx);
 static inline int nilfs_mark_inode_dirty(struct inode *inode)
 {
 	return __nilfs_mark_inode_dirty(inode, I_DIRTY);
diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c
index 06cb96462bf9..1944f5659267 100644
--- a/fs/ocfs2/extent_map.c
+++ b/fs/ocfs2/extent_map.c
@@ -749,9 +749,11 @@ static int ocfs2_fiemap_inline(struct inode *inode, struct buffer_head *di_bh,
 
 #define OCFS2_FIEMAP_FLAGS	(FIEMAP_FLAG_SYNC)
 
-int ocfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
-		 u64 map_start, u64 map_len)
+int ocfs2_fiemap(struct inode *inode, struct fiemap_ctx *f_ctx)
 {
+	struct fiemap_extent_info *fieinfo = f_ctx->fc_data;
+	u64 map_start = f_ctx->fc_start;
+	u64 map_len = f_ctx->fc_len;
 	int ret, is_last;
 	u32 mapping_end, cpos;
 	unsigned int hole_size;
diff --git a/fs/ocfs2/extent_map.h b/fs/ocfs2/extent_map.h
index 1057586ec19f..6c07fdf4d438 100644
--- a/fs/ocfs2/extent_map.h
+++ b/fs/ocfs2/extent_map.h
@@ -50,8 +50,7 @@ int ocfs2_get_clusters(struct inode *inode, u32 v_cluster, u32 *p_cluster,
 int ocfs2_extent_map_get_blocks(struct inode *inode, u64 v_blkno, u64 *p_blkno,
 				u64 *ret_count, unsigned int *extent_flags);
 
-int ocfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
-		 u64 map_start, u64 map_len);
+int ocfs2_fiemap(struct inode *inode, struct fiemap_ctx *f_ctx);
 
 int ocfs2_overwrite_io(struct inode *inode, struct buffer_head *di_bh,
 		       u64 map_start, u64 map_len);
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 3b7ed5d2279c..e56606c1ba92 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -456,9 +456,9 @@ int ovl_update_time(struct inode *inode, struct timespec64 *ts, int flags)
 	return 0;
 }
 
-static int ovl_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
-		      u64 start, u64 len)
+static int ovl_fiemap(struct inode *inode, struct fiemap_ctx *f_ctx)
 {
+	struct fiemap_extent_info *fieinfo = f_ctx->fc_data;
 	int err;
 	struct inode *realinode = ovl_inode_real(inode);
 	const struct cred *old_cred;
@@ -471,7 +471,7 @@ static int ovl_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 	if (fieinfo->fi_flags & FIEMAP_FLAG_SYNC)
 		filemap_write_and_wait(realinode->i_mapping);
 
-	err = realinode->i_op->fiemap(realinode, fieinfo, start, len);
+	err = realinode->i_op->fiemap(realinode, f_ctx);
 	revert_creds(old_cred);
 
 	return err;
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index f48ffd7a8d3e..d33d56fa8097 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -1093,11 +1093,12 @@ xfs_vn_update_time(
 STATIC int
 xfs_vn_fiemap(
 	struct inode		*inode,
-	struct fiemap_extent_info *fieinfo,
-	u64			start,
-	u64			length)
+	struct fiemap_ctx	*f_ctx)
 {
-	int			error;
+	struct fiemap_extent_info *fieinfo = f_ctx->fc_data;
+	u64 start  = f_ctx->fc_start;
+	u64 length = f_ctx->fc_len;
+	int error;
 
 	xfs_ilock(XFS_I(inode), XFS_IOLOCK_SHARED);
 	if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 1ac714e95d6b..bd8e8a7dfd59 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1688,6 +1688,9 @@ extern bool may_open_dev(const struct path *path);
 /*
  * VFS FS_IOC_FIEMAP helper definitions.
  */
+
+struct fiemap_ctx;
+
 struct fiemap_extent_info {
 	unsigned int fi_flags;		/* Flags as passed from user */
 	unsigned int fi_extents_mapped;	/* Number of mapped extents */
@@ -1695,6 +1698,18 @@ struct fiemap_extent_info {
 	struct fiemap_extent __user *fi_extents_start; /* Start of
 							fiemap_extent array */
 };
+
+typedef int (*fiemap_fill_cb)(struct fiemap_ctx *f_ctx, u64 logical,
+			      u64 phys, u64 len, u32 flags);
+
+struct fiemap_ctx {
+	unsigned int fc_flags;
+	void *fc_data;
+	fiemap_fill_cb fc_cb; /* Unused by now */
+	u64 fc_start;
+	u64 fc_len;
+};
+
 int fiemap_fill_next_extent(struct fiemap_extent_info *info, u64 logical,
 			    u64 phys, u64 len, u32 flags);
 int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags);
@@ -1822,8 +1837,7 @@ struct inode_operations {
 	int (*setattr) (struct dentry *, struct iattr *);
 	int (*getattr) (const struct path *, struct kstat *, u32, unsigned int);
 	ssize_t (*listxattr) (struct dentry *, char *, size_t);
-	int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start,
-		      u64 len);
+	int (*fiemap)(struct inode *, struct fiemap_ctx *);
 	int (*update_time)(struct inode *, struct timespec64 *, int);
 	int (*atomic_open)(struct inode *, struct dentry *,
 			   struct file *, unsigned open_flag,
@@ -3177,13 +3191,10 @@ static inline int vfs_fstat(int fd, struct kstat *stat)
 extern const char *vfs_get_link(struct dentry *, struct delayed_call *);
 extern int vfs_readlink(struct dentry *, char __user *, int);
 
-extern int __generic_block_fiemap(struct inode *inode,
-				  struct fiemap_extent_info *fieinfo,
-				  loff_t start, loff_t len,
+extern int __generic_block_fiemap(struct inode *inode, struct fiemap_ctx *f_ctx,
 				  get_block_t *get_block);
-extern int generic_block_fiemap(struct inode *inode,
-				struct fiemap_extent_info *fieinfo, u64 start,
-				u64 len, get_block_t *get_block);
+extern int generic_block_fiemap(struct inode *inode, struct fiemap_ctx *f_ctx,
+				get_block_t *get_block);
 
 extern struct file_system_type *get_filesystem(struct file_system_type *fs);
 extern void put_filesystem(struct file_system_type *fs);
-- 
2.17.1