bcachefs: Errcodes can now subtype standard error codes

The next patch is going to be adding private error codes for all the
places we return -ENOSPC.

Additionally, this patch updates return paths at all module boundaries
to call bch2_err_class(), to return the standard error code.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/errcode.c

@@ -15,7 +15,7 @@ static const char * const bch2_errcode_strs[] = {
 #define BCH_ERR_0	0
 
 static unsigned bch2_errcode_parents[] = {
-#define x(class, err) [BCH_ERR_##err - BCH_ERR_START] = BCH_ERR_##class,
+#define x(class, err) [BCH_ERR_##err - BCH_ERR_START] = class,
 	BCH_ERRCODES()
 #undef x
 };
@@ -49,3 +49,14 @@ bool __bch2_err_matches(int err, int class)
 
 	return err == class;
 }
+
+int __bch2_err_class(int err)
+{
+	err = -err;
+	BUG_ON((unsigned) err >= BCH_ERR_MAX);
+
+	while (err >= BCH_ERR_START && bch2_errcode_parents[err - BCH_ERR_START])
+		err = bch2_errcode_parents[err - BCH_ERR_START];
+
+	return -err;
+}

fs/bcachefs/errcode.h

@@ -3,51 +3,51 @@
 #define _BCACHEFS_ERRCODE_H
 
 #define BCH_ERRCODES()							\
-	x(0,			open_buckets_empty)			\
-	x(0,			freelist_empty)				\
-	x(freelist_empty,	no_buckets_found)			\
-	x(0,			insufficient_devices)			\
-	x(0,			transaction_restart)			\
-	x(transaction_restart,	transaction_restart_fault_inject)	\
-	x(transaction_restart,	transaction_restart_relock)		\
-	x(transaction_restart,	transaction_restart_relock_path)	\
-	x(transaction_restart,	transaction_restart_relock_path_intent)	\
-	x(transaction_restart,	transaction_restart_relock_after_fill)	\
-	x(transaction_restart,	transaction_restart_too_many_iters)	\
-	x(transaction_restart,	transaction_restart_lock_node_reused)	\
-	x(transaction_restart,	transaction_restart_fill_relock)	\
-	x(transaction_restart,	transaction_restart_fill_mem_alloc_fail)\
-	x(transaction_restart,	transaction_restart_mem_realloced)	\
-	x(transaction_restart,	transaction_restart_in_traverse_all)	\
-	x(transaction_restart,	transaction_restart_would_deadlock)	\
-	x(transaction_restart,	transaction_restart_would_deadlock_write)\
-	x(transaction_restart,	transaction_restart_upgrade)		\
-	x(transaction_restart,	transaction_restart_key_cache_upgrade)	\
-	x(transaction_restart,	transaction_restart_key_cache_fill)	\
-	x(transaction_restart,	transaction_restart_key_cache_raced)	\
-	x(transaction_restart,	transaction_restart_key_cache_realloced)\
-	x(transaction_restart,	transaction_restart_journal_preres_get)	\
-	x(transaction_restart,	transaction_restart_nested)		\
-	x(0,			no_btree_node)				\
-	x(no_btree_node,	no_btree_node_relock)			\
-	x(no_btree_node,	no_btree_node_upgrade)			\
-	x(no_btree_node,	no_btree_node_drop)			\
-	x(no_btree_node,	no_btree_node_lock_root)		\
-	x(no_btree_node,	no_btree_node_up)			\
-	x(no_btree_node,	no_btree_node_down)			\
-	x(no_btree_node,	no_btree_node_init)			\
-	x(no_btree_node,	no_btree_node_cached)			\
-	x(0,			lock_fail_node_reused)			\
-	x(0,			lock_fail_root_changed)			\
-	x(0,			journal_reclaim_would_deadlock)		\
-	x(0,			fsck)					\
-	x(fsck,			fsck_fix)				\
-	x(fsck,			fsck_ignore)				\
-	x(fsck,			fsck_errors_not_fixed)			\
-	x(fsck,			fsck_repair_unimplemented)		\
-	x(fsck,			fsck_repair_impossible)			\
-	x(0,			need_snapshot_cleanup)			\
-	x(0,			need_topology_repair)
+	x(0,				open_buckets_empty)			\
+	x(0,				freelist_empty)				\
+	x(BCH_ERR_freelist_empty,	no_buckets_found)			\
+	x(0,				insufficient_devices)			\
+	x(0,				transaction_restart)			\
+	x(BCH_ERR_transaction_restart,	transaction_restart_fault_inject)	\
+	x(BCH_ERR_transaction_restart,	transaction_restart_relock)		\
+	x(BCH_ERR_transaction_restart,	transaction_restart_relock_path)	\
+	x(BCH_ERR_transaction_restart,	transaction_restart_relock_path_intent)	\
+	x(BCH_ERR_transaction_restart,	transaction_restart_relock_after_fill)	\
+	x(BCH_ERR_transaction_restart,	transaction_restart_too_many_iters)	\
+	x(BCH_ERR_transaction_restart,	transaction_restart_lock_node_reused)	\
+	x(BCH_ERR_transaction_restart,	transaction_restart_fill_relock)	\
+	x(BCH_ERR_transaction_restart,	transaction_restart_fill_mem_alloc_fail)\
+	x(BCH_ERR_transaction_restart,	transaction_restart_mem_realloced)	\
+	x(BCH_ERR_transaction_restart,	transaction_restart_in_traverse_all)	\
+	x(BCH_ERR_transaction_restart,	transaction_restart_would_deadlock)	\
+	x(BCH_ERR_transaction_restart,	transaction_restart_would_deadlock_write)\
+	x(BCH_ERR_transaction_restart,	transaction_restart_upgrade)		\
+	x(BCH_ERR_transaction_restart,	transaction_restart_key_cache_upgrade)	\
+	x(BCH_ERR_transaction_restart,	transaction_restart_key_cache_fill)	\
+	x(BCH_ERR_transaction_restart,	transaction_restart_key_cache_raced)	\
+	x(BCH_ERR_transaction_restart,	transaction_restart_key_cache_realloced)\
+	x(BCH_ERR_transaction_restart,	transaction_restart_journal_preres_get)	\
+	x(BCH_ERR_transaction_restart,	transaction_restart_nested)		\
+	x(0,				no_btree_node)				\
+	x(BCH_ERR_no_btree_node,	no_btree_node_relock)			\
+	x(BCH_ERR_no_btree_node,	no_btree_node_upgrade)			\
+	x(BCH_ERR_no_btree_node,	no_btree_node_drop)			\
+	x(BCH_ERR_no_btree_node,	no_btree_node_lock_root)		\
+	x(BCH_ERR_no_btree_node,	no_btree_node_up)			\
+	x(BCH_ERR_no_btree_node,	no_btree_node_down)			\
+	x(BCH_ERR_no_btree_node,	no_btree_node_init)			\
+	x(BCH_ERR_no_btree_node,	no_btree_node_cached)			\
+	x(0,				lock_fail_node_reused)			\
+	x(0,				lock_fail_root_changed)			\
+	x(0,				journal_reclaim_would_deadlock)		\
+	x(0,				fsck)					\
+	x(BCH_ERR_fsck,			fsck_fix)				\
+	x(BCH_ERR_fsck,			fsck_ignore)				\
+	x(BCH_ERR_fsck,			fsck_errors_not_fixed)			\
+	x(BCH_ERR_fsck,			fsck_repair_unimplemented)		\
+	x(BCH_ERR_fsck,			fsck_repair_impossible)			\
+	x(0,				need_snapshot_cleanup)			\
+	x(0,				need_topology_repair)
 
 enum bch_errcode {
 	BCH_ERR_START		= 2048,
@@ -71,4 +71,11 @@ static inline bool _bch2_err_matches(int err, int class)
 	_bch2_err_matches(_err, _class);		\
 })
 
+int __bch2_err_class(int);
+
+static inline long bch2_err_class(long err)
+{
+	return err < 0 ? __bch2_err_class(err) : err;
+}
+
 #endif /* _BCACHFES_ERRCODE_H */

fs/bcachefs/fs-io.c

@@ -1186,7 +1186,7 @@ int bch2_read_folio(struct file *file, struct folio *folio)
 
 	ret = bch2_read_single_page(page, page->mapping);
 	folio_unlock(folio);
-	return ret;
+	return bch2_err_class(ret);
 }
 
 /* writepages: */
@@ -1465,7 +1465,7 @@ int bch2_writepages(struct address_space *mapping, struct writeback_control *wbc
 	if (w.io)
 		bch2_writepage_do_io(&w);
 	blk_finish_plug(&plug);
-	return ret;
+	return bch2_err_class(ret);
 }
 
 /* buffered writes: */
@@ -1550,7 +1550,7 @@ int bch2_write_begin(struct file *file, struct address_space *mapping,
 	bch2_pagecache_add_put(&inode->ei_pagecache_lock);
 	kfree(res);
 	*fsdata = NULL;
-	return ret;
+	return bch2_err_class(ret);
 }
 
 int bch2_write_end(struct file *file, struct address_space *mapping,
@@ -1975,7 +1975,7 @@ ssize_t bch2_read_iter(struct kiocb *iocb, struct iov_iter *iter)
 						iocb->ki_pos,
 						iocb->ki_pos + count - 1);
 			if (ret < 0)
-				return ret;
+				goto out;
 		}
 
 		file_accessed(file);
@@ -1991,8 +1991,8 @@ ssize_t bch2_read_iter(struct kiocb *iocb, struct iov_iter *iter)
 		ret = generic_file_read_iter(iocb, iter);
 		bch2_pagecache_add_put(&inode->ei_pagecache_lock);
 	}
-
-	return ret;
+out:
+	return bch2_err_class(ret);
 }
 
 /* O_DIRECT writes */
@@ -2224,6 +2224,9 @@ static long bch2_dio_write_loop(struct dio_write *dio)
 	/* inode->i_dio_count is our ref on inode and thus bch_fs */
 	inode_dio_end(&inode->v);
 
+	if (ret < 0)
+		ret = bch2_err_class(ret);
+
 	if (!sync) {
 		req->ki_complete(req, ret);
 		ret = -EIOCBQUEUED;
@@ -2332,8 +2335,10 @@ ssize_t bch2_write_iter(struct kiocb *iocb, struct iov_iter *from)
 	struct bch_inode_info *inode = file_bch_inode(file);
 	ssize_t	ret;
 
-	if (iocb->ki_flags & IOCB_DIRECT)
-		return bch2_direct_write(iocb, from);
+	if (iocb->ki_flags & IOCB_DIRECT) {
+		ret = bch2_direct_write(iocb, from);
+		goto out;
+	}
 
 	inode_lock(&inode->v);
 
@@ -2357,8 +2362,8 @@ ssize_t bch2_write_iter(struct kiocb *iocb, struct iov_iter *from)
 
 	if (ret > 0)
 		ret = generic_write_sync(iocb, ret);
-
-	return ret;
+out:
+	return bch2_err_class(ret);
 }
 
 /* fsync: */
@@ -2392,7 +2397,7 @@ int bch2_fsync(struct file *file, loff_t start, loff_t end, int datasync)
 	ret2 = sync_inode_metadata(&inode->v, 1);
 	ret3 = bch2_flush_inode(c, inode_inum(inode));
 
-	return ret ?: ret2 ?: ret3;
+	return bch2_err_class(ret ?: ret2 ?: ret3);
 }
 
 /* truncate: */
@@ -2698,7 +2703,7 @@ int bch2_truncate(struct mnt_idmap *idmap,
 	ret = bch2_setattr_nonsize(idmap, inode, iattr);
 err:
 	bch2_pagecache_block_put(&inode->ei_pagecache_lock);
-	return ret;
+	return bch2_err_class(ret);
 }
 
 /* fallocate: */
@@ -3128,7 +3133,7 @@ long bch2_fallocate_dispatch(struct file *file, int mode,
 	inode_unlock(&inode->v);
 	percpu_ref_put(&c->writes);
 
-	return ret;
+	return bch2_err_class(ret);
 }
 
 loff_t bch2_remap_file_range(struct file *file_src, loff_t pos_src,
@@ -3206,7 +3211,7 @@ loff_t bch2_remap_file_range(struct file *file_src, loff_t pos_src,
 err:
 	bch2_unlock_inodes(INODE_LOCK|INODE_PAGECACHE_BLOCK, src, dst);
 
-	return ret;
+	return bch2_err_class(ret);
 }
 
 /* fseek: */
@@ -3431,18 +3436,26 @@ static loff_t bch2_seek_hole(struct file *file, u64 offset)
 
 loff_t bch2_llseek(struct file *file, loff_t offset, int whence)
 {
+	loff_t ret;
+
 	switch (whence) {
 	case SEEK_SET:
 	case SEEK_CUR:
 	case SEEK_END:
-		return generic_file_llseek(file, offset, whence);
+		ret = generic_file_llseek(file, offset, whence);
+		break;
 	case SEEK_DATA:
-		return bch2_seek_data(file, offset);
+		ret = bch2_seek_data(file, offset);
+		break;
 	case SEEK_HOLE:
-		return bch2_seek_hole(file, offset);
+		ret = bch2_seek_hole(file, offset);
+		break;
+	default:
+		ret = -EINVAL;
+		break;
 	}
 
-	return -EINVAL;
+	return bch2_err_class(ret);
 }
 
 void bch2_fs_fsio_exit(struct bch_fs *c)

fs/bcachefs/fs-ioctl.c

@@ -455,51 +455,67 @@ long bch2_fs_file_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 {
 	struct bch_inode_info *inode = file_bch_inode(file);
 	struct bch_fs *c = inode->v.i_sb->s_fs_info;
+	long ret;
 
 	switch (cmd) {
 	case FS_IOC_GETFLAGS:
-		return bch2_ioc_getflags(inode, (int __user *) arg);
+		ret = bch2_ioc_getflags(inode, (int __user *) arg);
+		break;
 
 	case FS_IOC_SETFLAGS:
-		return bch2_ioc_setflags(c, file, inode, (int __user *) arg);
+		ret = bch2_ioc_setflags(c, file, inode, (int __user *) arg);
+		break;
 
 	case FS_IOC_FSGETXATTR:
-		return bch2_ioc_fsgetxattr(inode, (void __user *) arg);
+		ret = bch2_ioc_fsgetxattr(inode, (void __user *) arg);
+		break;
+
 	case FS_IOC_FSSETXATTR:
-		return bch2_ioc_fssetxattr(c, file, inode,
-					   (void __user *) arg);
+		ret = bch2_ioc_fssetxattr(c, file, inode,
+					  (void __user *) arg);
+		break;
 
 	case BCHFS_IOC_REINHERIT_ATTRS:
-		return bch2_ioc_reinherit_attrs(c, file, inode,
-						(void __user *) arg);
+		ret = bch2_ioc_reinherit_attrs(c, file, inode,
+					       (void __user *) arg);
+		break;
 
 	case FS_IOC_GETVERSION:
-		return -ENOTTY;
+		ret = -ENOTTY;
+		break;
+
 	case FS_IOC_SETVERSION:
-		return -ENOTTY;
+		ret = -ENOTTY;
+		break;
 
 	case FS_IOC_GOINGDOWN:
-		return bch2_ioc_goingdown(c, (u32 __user *) arg);
+		ret = bch2_ioc_goingdown(c, (u32 __user *) arg);
+		break;
 
 	case BCH_IOCTL_SUBVOLUME_CREATE: {
 		struct bch_ioctl_subvolume i;
 
-		if (copy_from_user(&i, (void __user *) arg, sizeof(i)))
-			return -EFAULT;
-		return bch2_ioctl_subvolume_create(c, file, i);
+		ret = copy_from_user(&i, (void __user *) arg, sizeof(i))
+			? -EFAULT
+			: bch2_ioctl_subvolume_create(c, file, i);
+		break;
 	}
 
 	case BCH_IOCTL_SUBVOLUME_DESTROY: {
 		struct bch_ioctl_subvolume i;
 
-		if (copy_from_user(&i, (void __user *) arg, sizeof(i)))
-			return -EFAULT;
-		return bch2_ioctl_subvolume_destroy(c, file, i);
+		ret = copy_from_user(&i, (void __user *) arg, sizeof(i))
+			? -EFAULT
+			: bch2_ioctl_subvolume_destroy(c, file, i);
+		break;
 	}
 
 	default:
-		return bch2_fs_ioctl(c, cmd, (void __user *) arg);
+		ret = bch2_fs_ioctl(c, cmd, (void __user *) arg);
+		break;
 	}
+
+	return bch2_err_class(ret);
 }
 
 #ifdef CONFIG_COMPAT

fs/bcachefs/fs.c

@@ -419,7 +419,7 @@ static int bch2_mknod(struct mnt_idmap *idmap,
 			      (subvol_inum) { 0 }, 0);
 
 	if (IS_ERR(inode))
-		return PTR_ERR(inode);
+		return bch2_err_class(PTR_ERR(inode));
 
 	d_instantiate(dentry, &inode->v);
 	return 0;
@@ -529,7 +529,7 @@ static int bch2_symlink(struct mnt_idmap *idmap,
 	inode = __bch2_create(idmap, dir, dentry, S_IFLNK|S_IRWXUGO, 0,
 			      (subvol_inum) { 0 }, BCH_CREATE_TMPFILE);
 	if (unlikely(IS_ERR(inode)))
-		return PTR_ERR(inode);
+		return bch2_err_class(PTR_ERR(inode));
 
 	inode_lock(&inode->v);
 	ret = page_symlink(&inode->v, symname, strlen(symname) + 1);
@@ -769,7 +769,7 @@ int bch2_setattr_nonsize(struct mnt_idmap *idmap,
 err:
 	mutex_unlock(&inode->ei_update_lock);
 
-	return ret;
+	return bch2_err_class(ret);
 }
 
 static int bch2_getattr(struct mnt_idmap *idmap,
@@ -839,7 +839,7 @@ static int bch2_tmpfile(struct mnt_idmap *idmap,
 			      (subvol_inum) { 0 }, BCH_CREATE_TMPFILE);
 
 	if (IS_ERR(inode))
-		return PTR_ERR(inode);
+		return bch2_err_class(PTR_ERR(inode));
 
 	d_mark_tmpfile(file, &inode->v);
 	d_instantiate(file->f_path.dentry, &inode->v);
@@ -1454,7 +1454,7 @@ static int bch2_vfs_write_inode(struct inode *vinode,
 			       ATTR_ATIME|ATTR_MTIME|ATTR_CTIME);
 	mutex_unlock(&inode->ei_update_lock);
 
-	return ret;
+	return bch2_err_class(ret);
 }
 
 static void bch2_evict_inode(struct inode *vinode)
@@ -1558,6 +1558,7 @@ static int bch2_statfs(struct dentry *dentry, struct kstatfs *buf)
 static int bch2_sync_fs(struct super_block *sb, int wait)
 {
 	struct bch_fs *c = sb->s_fs_info;
+	int ret;
 
 	if (c->opts.journal_flush_disabled)
 		return 0;
@@ -1567,7 +1568,8 @@ static int bch2_sync_fs(struct super_block *sb, int wait)
 		return 0;
 	}
 
-	return bch2_journal_flush(&c->journal);
+	ret = bch2_journal_flush(&c->journal);
+	return bch2_err_class(ret);
 }
 
 static struct bch_fs *bch2_path_to_fs(const char *path)
@@ -1623,7 +1625,7 @@ static int bch2_remount(struct super_block *sb, int *flags, char *data)
 
 	ret = bch2_parse_mount_opts(c, &opts, data);
 	if (ret)
-		return ret;
+		goto err;
 
 	if (opts.read_only != c->opts.read_only) {
 		down_write(&c->state_lock);
@@ -1637,7 +1639,8 @@ static int bch2_remount(struct super_block *sb, int *flags, char *data)
 			if (ret) {
 				bch_err(c, "error going rw: %i", ret);
 				up_write(&c->state_lock);
-				return -EINVAL;
+				ret = -EINVAL;
+				goto err;
 			}
 
 			sb->s_flags &= ~SB_RDONLY;
@@ -1650,8 +1653,8 @@ static int bch2_remount(struct super_block *sb, int *flags, char *data)
 
 	if (opts.errors >= 0)
 		c->opts.errors = opts.errors;
-
-	return ret;
+err:
+	return bch2_err_class(ret);
 }
 
 static int bch2_show_devname(struct seq_file *seq, struct dentry *root)

fs/bcachefs/sysfs.c

@@ -40,14 +40,14 @@
 #include "util.h"
 
 #define SYSFS_OPS(type)							\
-const struct sysfs_ops type ## _sysfs_ops = {					\
+const struct sysfs_ops type ## _sysfs_ops = {				\
 	.show	= type ## _show,					\
 	.store	= type ## _store					\
 }
 
 #define SHOW(fn)							\
 static ssize_t fn ## _to_text(struct printbuf *,			\
-			      struct kobject *, struct attribute *);\
+			      struct kobject *, struct attribute *);	\
 									\
 static ssize_t fn ## _show(struct kobject *kobj, struct attribute *attr,\
 			   char *buf)					\
@@ -66,15 +66,24 @@ static ssize_t fn ## _show(struct kobject *kobj, struct attribute *attr,\
 		memcpy(buf, out.buf, ret);				\
 	}								\
 	printbuf_exit(&out);						\
-	return ret;							\
+	return bch2_err_class(ret);					\
 }									\
 									\
 static ssize_t fn ## _to_text(struct printbuf *out, struct kobject *kobj,\
 			      struct attribute *attr)
 
 #define STORE(fn)							\
+static ssize_t fn ## _store_inner(struct kobject *, struct attribute *,\
+			    const char *, size_t);			\
+									\
 static ssize_t fn ## _store(struct kobject *kobj, struct attribute *attr,\
 			    const char *buf, size_t size)		\
+{									\
+	return bch2_err_class(fn##_store_inner(kobj, attr, buf, size));	\
+}									\
+									\
+static ssize_t fn ## _store_inner(struct kobject *kobj, struct attribute *attr,\
+				  const char *buf, size_t size)
 
 #define __sysfs_attribute(_name, _mode)					\
 	static struct attribute sysfs_##_name =				\

fs/bcachefs/xattr.c

@@ -350,17 +350,19 @@ ssize_t bch2_xattr_list(struct dentry *dentry, char *buffer, size_t buffer_size)
 	bch2_trans_exit(&trans);
 
 	if (ret)
-		return ret;
+		goto out;
 
 	ret = bch2_xattr_list_bcachefs(c, &inode->ei_inode, &buf, false);
 	if (ret)
-		return ret;
+		goto out;
 
 	ret = bch2_xattr_list_bcachefs(c, &inode->ei_inode, &buf, true);
 	if (ret)
-		return ret;
+		goto out;
 
 	return buf.used;
+out:
+	return bch2_err_class(ret);
 }
 
 static int bch2_xattr_get_handler(const struct xattr_handler *handler,
@@ -369,8 +371,10 @@ static int bch2_xattr_get_handler(const struct xattr_handler *handler,
 {
 	struct bch_inode_info *inode = to_bch_ei(vinode);
 	struct bch_fs *c = inode->v.i_sb->s_fs_info;
+	int ret;
 
-	return bch2_xattr_get(c, inode, name, buffer, size, handler->flags);
+	ret = bch2_xattr_get(c, inode, name, buffer, size, handler->flags);
+	return bch2_err_class(ret);
 }
 
 static int bch2_xattr_set_handler(const struct xattr_handler *handler,
@@ -382,11 +386,13 @@ static int bch2_xattr_set_handler(const struct xattr_handler *handler,
 	struct bch_inode_info *inode = to_bch_ei(vinode);
 	struct bch_fs *c = inode->v.i_sb->s_fs_info;
 	struct bch_hash_info hash = bch2_hash_info_init(c, &inode->ei_inode);
+	int ret;
 
-	return bch2_trans_do(c, NULL, NULL, 0,
+	ret = bch2_trans_do(c, NULL, NULL, 0,
 			bch2_xattr_set(&trans, inode_inum(inode), &hash,
 				       name, value, size,
 				       handler->flags, flags));
+	return bch2_err_class(ret);
 }
 
 static const struct xattr_handler bch_xattr_user_handler = {