[PATCH v7 1/3] fs: add offset parameter to iterate_dir function

[Stefan Roesch <shr@fb.com>]

This change adds the offset parameter to the iterate_dir
function. The offset paramater allows the caller to specify
the offset position.

This change is required to support getdents in io_uring.

Signed-off-by: Stefan Roesch <shr@fb.com>
---
 arch/alpha/kernel/osf_sys.c |  2 +-
 fs/ecryptfs/file.c          |  2 +-
 fs/exportfs/expfs.c         |  2 +-
 fs/ksmbd/smb2pdu.c          |  3 ++-
 fs/ksmbd/vfs.c              |  4 ++--
 fs/nfsd/nfs4recover.c       |  2 +-
 fs/nfsd/vfs.c               |  2 +-
 fs/overlayfs/readdir.c      |  6 +++---
 fs/readdir.c                | 28 ++++++++++++++++++----------
 include/linux/fs.h          |  2 +-
 10 files changed, 31 insertions(+), 22 deletions(-)

diff --git a/arch/alpha/kernel/osf_sys.c b/arch/alpha/kernel/osf_sys.c
index 8bbeebb73cf0..cf68c459bca6 100644
--- a/arch/alpha/kernel/osf_sys.c
+++ b/arch/alpha/kernel/osf_sys.c
@@ -162,7 +162,7 @@ SYSCALL_DEFINE4(osf_getdirentries, unsigned int, fd,
 	if (!arg.file)
 		return -EBADF;
 
-	error = iterate_dir(arg.file, &buf.ctx);
+	error = iterate_dir(arg.file, &buf.ctx, &arg.file->f_pos);
 	if (error >= 0)
 		error = buf.error;
 	if (count != buf.count)
diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
index 18d5b91cb573..b68f1945e615 100644
--- a/fs/ecryptfs/file.c
+++ b/fs/ecryptfs/file.c
@@ -109,7 +109,7 @@ static int ecryptfs_readdir(struct file *file, struct dir_context *ctx)
 		.sb = inode->i_sb,
 	};
 	lower_file = ecryptfs_file_to_lower(file);
-	rc = iterate_dir(lower_file, &buf.ctx);
+	rc = iterate_dir(lower_file, &buf.ctx, &lower_file->f_pos);
 	ctx->pos = buf.ctx.pos;
 	if (rc < 0)
 		goto out;
diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c
index 0106eba46d5a..654e2d4b1d4f 100644
--- a/fs/exportfs/expfs.c
+++ b/fs/exportfs/expfs.c
@@ -323,7 +323,7 @@ static int get_name(const struct path *path, char *name, struct dentry *child)
 	while (1) {
 		int old_seq = buffer.sequence;
 
-		error = iterate_dir(file, &buffer.ctx);
+		error = iterate_dir(file, &buffer.ctx, &file->f_pos);
 		if (buffer.found) {
 			error = 0;
 			break;
diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c
index 49c9da37315c..fd4cb995d06d 100644
--- a/fs/ksmbd/smb2pdu.c
+++ b/fs/ksmbd/smb2pdu.c
@@ -3925,7 +3925,8 @@ int smb2_query_dir(struct ksmbd_work *work)
 	dir_fp->readdir_data.private		= &query_dir_private;
 	set_ctx_actor(&dir_fp->readdir_data.ctx, __query_dir);
 
-	rc = iterate_dir(dir_fp->filp, &dir_fp->readdir_data.ctx);
+	rc = iterate_dir(dir_fp->filp, &dir_fp->readdir_data.ctx,
+			&dir_fp->filp->f_pos);
 	if (rc == 0)
 		restart_ctx(&dir_fp->readdir_data.ctx);
 	if (rc == -ENOSPC)
diff --git a/fs/ksmbd/vfs.c b/fs/ksmbd/vfs.c
index 19d36393974c..5b8e23d3c846 100644
--- a/fs/ksmbd/vfs.c
+++ b/fs/ksmbd/vfs.c
@@ -1136,7 +1136,7 @@ int ksmbd_vfs_empty_dir(struct ksmbd_file *fp)
 	set_ctx_actor(&readdir_data.ctx, __dir_empty);
 	readdir_data.dirent_count = 0;
 
-	err = iterate_dir(fp->filp, &readdir_data.ctx);
+	err = iterate_dir(fp->filp, &readdir_data.ctx, &fp->filp->f_pos);
 	if (readdir_data.dirent_count > 2)
 		err = -ENOTEMPTY;
 	else
@@ -1186,7 +1186,7 @@ static int ksmbd_vfs_lookup_in_dir(struct path *dir, char *name, size_t namelen)
 	if (IS_ERR(dfilp))
 		return PTR_ERR(dfilp);
 
-	ret = iterate_dir(dfilp, &readdir_data.ctx);
+	ret = iterate_dir(dfilp, &readdir_data.ctx, &dfilp->f_pos);
 	if (readdir_data.dirent_count > 0)
 		ret = 0;
 	fput(dfilp);
diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
index 6fedc49726bf..79a2799891e4 100644
--- a/fs/nfsd/nfs4recover.c
+++ b/fs/nfsd/nfs4recover.c
@@ -307,7 +307,7 @@ nfsd4_list_rec_dir(recdir_func *f, struct nfsd_net *nn)
 		return status;
 	}
 
-	status = iterate_dir(nn->rec_file, &ctx.ctx);
+	status = iterate_dir(nn->rec_file, &ctx.ctx, &nn->rec_file->f_pos);
 	inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
 
 	list_for_each_entry_safe(entry, tmp, &ctx.names, list) {
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index c99857689e2c..085864c25318 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1980,7 +1980,7 @@ static __be32 nfsd_buffered_readdir(struct file *file, struct svc_fh *fhp,
 		buf.used = 0;
 		buf.full = 0;
 
-		host_err = iterate_dir(file, &buf.ctx);
+		host_err = iterate_dir(file, &buf.ctx, &file->f_pos);
 		if (buf.full)
 			host_err = 0;
 
diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
index 150fdf3bc68d..52167ff9e513 100644
--- a/fs/overlayfs/readdir.c
+++ b/fs/overlayfs/readdir.c
@@ -306,7 +306,7 @@ static inline int ovl_dir_read(struct path *realpath,
 	do {
 		rdd->count = 0;
 		rdd->err = 0;
-		err = iterate_dir(realfile, &rdd->ctx);
+		err = iterate_dir(realfile, &rdd->ctx, &realfile->f_pos);
 		if (err >= 0)
 			err = rdd->err;
 	} while (!err && rdd->count);
@@ -722,7 +722,7 @@ static int ovl_iterate_real(struct file *file, struct dir_context *ctx)
 			return PTR_ERR(rdt.cache);
 	}
 
-	err = iterate_dir(od->realfile, &rdt.ctx);
+	err = iterate_dir(od->realfile, &rdt.ctx, &od->realfile->f_pos);
 	ctx->pos = rdt.ctx.pos;
 
 	return err;
@@ -753,7 +753,7 @@ static int ovl_iterate(struct file *file, struct dir_context *ctx)
 		      OVL_TYPE_MERGE(ovl_path_type(dentry->d_parent))))) {
 			err = ovl_iterate_real(file, ctx);
 		} else {
-			err = iterate_dir(od->realfile, ctx);
+			err = iterate_dir(od->realfile, ctx, &od->realfile->f_pos);
 		}
 		goto out;
 	}
diff --git a/fs/readdir.c b/fs/readdir.c
index 09e8ed7d4161..c1e6612e0f47 100644
--- a/fs/readdir.c
+++ b/fs/readdir.c
@@ -36,8 +36,13 @@
 	unsafe_copy_to_user(dst, src, len, label);		\
 } while (0)
 
-
-int iterate_dir(struct file *file, struct dir_context *ctx)
+/**
+ * iterate_dir - iterate over directory
+ * @file    : pointer to file struct of directory
+ * @ctx     : pointer to directory ctx structure
+ * @pos     : file offset
+ */
+int iterate_dir(struct file *file, struct dir_context *ctx, loff_t *pos)
 {
 	struct inode *inode = file_inode(file);
 	bool shared = false;
@@ -60,12 +65,15 @@ int iterate_dir(struct file *file, struct dir_context *ctx)
 
 	res = -ENOENT;
 	if (!IS_DEADDIR(inode)) {
-		ctx->pos = file->f_pos;
+		ctx->pos = *pos;
+
 		if (shared)
 			res = file->f_op->iterate_shared(file, ctx);
 		else
 			res = file->f_op->iterate(file, ctx);
-		file->f_pos = ctx->pos;
+
+		*pos = ctx->pos;
+
 		fsnotify_access(file);
 		file_accessed(file);
 	}
@@ -190,7 +198,7 @@ SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
 	if (!f.file)
 		return -EBADF;
 
-	error = iterate_dir(f.file, &buf.ctx);
+	error = iterate_dir(f.file, &buf.ctx, &f.file->f_pos);
 	if (buf.result)
 		error = buf.result;
 
@@ -283,7 +291,7 @@ SYSCALL_DEFINE3(getdents, unsigned int, fd,
 	if (!f.file)
 		return -EBADF;
 
-	error = iterate_dir(f.file, &buf.ctx);
+	error = iterate_dir(f.file, &buf.ctx, &f.file->f_pos);
 	if (error >= 0)
 		error = buf.error;
 	if (buf.prev_reclen) {
@@ -366,7 +374,7 @@ SYSCALL_DEFINE3(getdents64, unsigned int, fd,
 	if (!f.file)
 		return -EBADF;
 
-	error = iterate_dir(f.file, &buf.ctx);
+	error = iterate_dir(f.file, &buf.ctx, &f.file->f_pos);
 	if (error >= 0)
 		error = buf.error;
 	if (buf.prev_reclen) {
@@ -379,7 +387,7 @@ SYSCALL_DEFINE3(getdents64, unsigned int, fd,
 		else
 			error = count - buf.count;
 	}
-	fdput_pos(f);
+
 	return error;
 }
 
@@ -448,7 +456,7 @@ COMPAT_SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
 	if (!f.file)
 		return -EBADF;
 
-	error = iterate_dir(f.file, &buf.ctx);
+	error = iterate_dir(f.file, &buf.ctx, &f.file->f_pos);
 	if (buf.result)
 		error = buf.result;
 
@@ -534,7 +542,7 @@ COMPAT_SYSCALL_DEFINE3(getdents, unsigned int, fd,
 	if (!f.file)
 		return -EBADF;
 
-	error = iterate_dir(f.file, &buf.ctx);
+	error = iterate_dir(f.file, &buf.ctx, &f.file->f_pos);
 	if (error >= 0)
 		error = buf.error;
 	if (buf.prev_reclen) {
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 6b8dc1a78df6..e1becbe86b07 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -3340,7 +3340,7 @@ const char *simple_get_link(struct dentry *, struct inode *,
 			    struct delayed_call *);
 extern const struct inode_operations simple_symlink_inode_operations;
 
-extern int iterate_dir(struct file *, struct dir_context *);
+extern int iterate_dir(struct file *, struct dir_context *, loff_t *pos);
 
 int vfs_fstatat(int dfd, const char __user *filename, struct kstat *stat,
 		int flags);
-- 
2.30.2