1 files changed, 501 insertions, 0 deletions

diff --git a/fs/bcachefs/fs-common.c b/fs/bcachefs/fs-common.c
new file mode 100644
index 0000000000..4496cf91a4
--- /dev/null
+++ b/fs/bcachefs/fs-common.c
@@ -0,0 +1,501 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "bcachefs.h"
+#include "acl.h"
+#include "btree_update.h"
+#include "dirent.h"
+#include "fs-common.h"
+#include "inode.h"
+#include "subvolume.h"
+#include "xattr.h"
+
+#include <linux/posix_acl.h>
+
+static inline int is_subdir_for_nlink(struct bch_inode_unpacked *inode)
+{
+	return S_ISDIR(inode->bi_mode) && !inode->bi_subvol;
+}
+
+int bch2_create_trans(struct btree_trans *trans,
+		      subvol_inum dir,
+		      struct bch_inode_unpacked *dir_u,
+		      struct bch_inode_unpacked *new_inode,
+		      const struct qstr *name,
+		      uid_t uid, gid_t gid, umode_t mode, dev_t rdev,
+		      struct posix_acl *default_acl,
+		      struct posix_acl *acl,
+		      subvol_inum snapshot_src,
+		      unsigned flags)
+{
+	struct bch_fs *c = trans->c;
+	struct btree_iter dir_iter = { NULL };
+	struct btree_iter inode_iter = { NULL };
+	subvol_inum new_inum = dir;
+	u64 now = bch2_current_time(c);
+	u64 cpu = raw_smp_processor_id();
+	u64 dir_target;
+	u32 snapshot;
+	unsigned dir_type = mode_to_type(mode);
+	int ret;
+
+	ret = bch2_subvolume_get_snapshot(trans, dir.subvol, &snapshot);
+	if (ret)
+		goto err;
+
+	ret = bch2_inode_peek(trans, &dir_iter, dir_u, dir, BTREE_ITER_INTENT);
+	if (ret)
+		goto err;
+
+	if (!(flags & BCH_CREATE_SNAPSHOT)) {
+		/* Normal create path - allocate a new inode: */
+		bch2_inode_init_late(new_inode, now, uid, gid, mode, rdev, dir_u);
+
+		if (flags & BCH_CREATE_TMPFILE)
+			new_inode->bi_flags |= BCH_INODE_unlinked;
+
+		ret = bch2_inode_create(trans, &inode_iter, new_inode, snapshot, cpu);
+		if (ret)
+			goto err;
+
+		snapshot_src = (subvol_inum) { 0 };
+	} else {
+		/*
+		 * Creating a snapshot - we're not allocating a new inode, but
+		 * we do have to lookup the root inode of the subvolume we're
+		 * snapshotting and update it (in the new snapshot):
+		 */
+
+		if (!snapshot_src.inum) {
+			/* Inode wasn't specified, just snapshot: */
+			struct bch_subvolume s;
+
+			ret = bch2_subvolume_get(trans, snapshot_src.subvol, true,
+						 BTREE_ITER_CACHED, &s);
+			if (ret)
+				goto err;
+
+			snapshot_src.inum = le64_to_cpu(s.inode);
+		}
+
+		ret = bch2_inode_peek(trans, &inode_iter, new_inode, snapshot_src,
+				      BTREE_ITER_INTENT);
+		if (ret)
+			goto err;
+
+		if (new_inode->bi_subvol != snapshot_src.subvol) {
+			/* Not a subvolume root: */
+			ret = -EINVAL;
+			goto err;
+		}
+
+		/*
+		 * If we're not root, we have to own the subvolume being
+		 * snapshotted:
+		 */
+		if (uid && new_inode->bi_uid != uid) {
+			ret = -EPERM;
+			goto err;
+		}
+
+		flags |= BCH_CREATE_SUBVOL;
+	}
+
+	new_inum.inum	= new_inode->bi_inum;
+	dir_target	= new_inode->bi_inum;
+
+	if (flags & BCH_CREATE_SUBVOL) {
+		u32 new_subvol, dir_snapshot;
+
+		ret = bch2_subvolume_create(trans, new_inode->bi_inum,
+					    snapshot_src.subvol,
+					    &new_subvol, &snapshot,
+					    (flags & BCH_CREATE_SNAPSHOT_RO) != 0);
+		if (ret)
+			goto err;
+
+		new_inode->bi_parent_subvol	= dir.subvol;
+		new_inode->bi_subvol		= new_subvol;
+		new_inum.subvol			= new_subvol;
+		dir_target			= new_subvol;
+		dir_type			= DT_SUBVOL;
+
+		ret = bch2_subvolume_get_snapshot(trans, dir.subvol, &dir_snapshot);
+		if (ret)
+			goto err;
+
+		bch2_btree_iter_set_snapshot(&dir_iter, dir_snapshot);
+		ret = bch2_btree_iter_traverse(&dir_iter);
+		if (ret)
+			goto err;
+	}
+
+	if (!(flags & BCH_CREATE_SNAPSHOT)) {
+		if (default_acl) {
+			ret = bch2_set_acl_trans(trans, new_inum, new_inode,
+						 default_acl, ACL_TYPE_DEFAULT);
+			if (ret)
+				goto err;
+		}
+
+		if (acl) {
+			ret = bch2_set_acl_trans(trans, new_inum, new_inode,
+						 acl, ACL_TYPE_ACCESS);
+			if (ret)
+				goto err;
+		}
+	}
+
+	if (!(flags & BCH_CREATE_TMPFILE)) {
+		struct bch_hash_info dir_hash = bch2_hash_info_init(c, dir_u);
+		u64 dir_offset;
+
+		if (is_subdir_for_nlink(new_inode))
+			dir_u->bi_nlink++;
+		dir_u->bi_mtime = dir_u->bi_ctime = now;
+
+		ret = bch2_inode_write(trans, &dir_iter, dir_u);
+		if (ret)
+			goto err;
+
+		ret = bch2_dirent_create(trans, dir, &dir_hash,
+					 dir_type,
+					 name,
+					 dir_target,
+					 &dir_offset,
+					 BCH_HASH_SET_MUST_CREATE);
+		if (ret)
+			goto err;
+
+		if (c->sb.version >= bcachefs_metadata_version_inode_backpointers) {
+			new_inode->bi_dir		= dir_u->bi_inum;
+			new_inode->bi_dir_offset	= dir_offset;
+		}
+	}
+
+	inode_iter.flags &= ~BTREE_ITER_ALL_SNAPSHOTS;
+	bch2_btree_iter_set_snapshot(&inode_iter, snapshot);
+
+	ret   = bch2_btree_iter_traverse(&inode_iter) ?:
+		bch2_inode_write(trans, &inode_iter, new_inode);
+err:
+	bch2_trans_iter_exit(trans, &inode_iter);
+	bch2_trans_iter_exit(trans, &dir_iter);
+	return ret;
+}
+
+int bch2_link_trans(struct btree_trans *trans,
+		    subvol_inum dir,  struct bch_inode_unpacked *dir_u,
+		    subvol_inum inum, struct bch_inode_unpacked *inode_u,
+		    const struct qstr *name)
+{
+	struct bch_fs *c = trans->c;
+	struct btree_iter dir_iter = { NULL };
+	struct btree_iter inode_iter = { NULL };
+	struct bch_hash_info dir_hash;
+	u64 now = bch2_current_time(c);
+	u64 dir_offset = 0;
+	int ret;
+
+	if (dir.subvol != inum.subvol)
+		return -EXDEV;
+
+	ret = bch2_inode_peek(trans, &inode_iter, inode_u, inum, BTREE_ITER_INTENT);
+	if (ret)
+		goto err;
+
+	inode_u->bi_ctime = now;
+	ret = bch2_inode_nlink_inc(inode_u);
+	if (ret)
+		return ret;
+
+	ret = bch2_inode_peek(trans, &dir_iter, dir_u, dir, BTREE_ITER_INTENT);
+	if (ret)
+		goto err;
+
+	if (bch2_reinherit_attrs(inode_u, dir_u)) {
+		ret = -EXDEV;
+		goto err;
+	}
+
+	dir_u->bi_mtime = dir_u->bi_ctime = now;
+
+	dir_hash = bch2_hash_info_init(c, dir_u);
+
+	ret = bch2_dirent_create(trans, dir, &dir_hash,
+				 mode_to_type(inode_u->bi_mode),
+				 name, inum.inum, &dir_offset,
+				 BCH_HASH_SET_MUST_CREATE);
+	if (ret)
+		goto err;
+
+	if (c->sb.version >= bcachefs_metadata_version_inode_backpointers) {
+		inode_u->bi_dir		= dir.inum;
+		inode_u->bi_dir_offset	= dir_offset;
+	}
+
+	ret =   bch2_inode_write(trans, &dir_iter, dir_u) ?:
+		bch2_inode_write(trans, &inode_iter, inode_u);
+err:
+	bch2_trans_iter_exit(trans, &dir_iter);
+	bch2_trans_iter_exit(trans, &inode_iter);
+	return ret;
+}
+
+int bch2_unlink_trans(struct btree_trans *trans,
+		      subvol_inum dir,
+		      struct bch_inode_unpacked *dir_u,
+		      struct bch_inode_unpacked *inode_u,
+		      const struct qstr *name,
+		      bool deleting_snapshot)
+{
+	struct bch_fs *c = trans->c;
+	struct btree_iter dir_iter = { NULL };
+	struct btree_iter dirent_iter = { NULL };
+	struct btree_iter inode_iter = { NULL };
+	struct bch_hash_info dir_hash;
+	subvol_inum inum;
+	u64 now = bch2_current_time(c);
+	struct bkey_s_c k;
+	int ret;
+
+	ret = bch2_inode_peek(trans, &dir_iter, dir_u, dir, BTREE_ITER_INTENT);
+	if (ret)
+		goto err;
+
+	dir_hash = bch2_hash_info_init(c, dir_u);
+
+	ret = __bch2_dirent_lookup_trans(trans, &dirent_iter, dir, &dir_hash,
+					 name, &inum, BTREE_ITER_INTENT);
+	if (ret)
+		goto err;
+
+	ret = bch2_inode_peek(trans, &inode_iter, inode_u, inum,
+			      BTREE_ITER_INTENT);
+	if (ret)
+		goto err;
+
+	if (!deleting_snapshot && S_ISDIR(inode_u->bi_mode)) {
+		ret = bch2_empty_dir_trans(trans, inum);
+		if (ret)
+			goto err;
+	}
+
+	if (deleting_snapshot && !inode_u->bi_subvol) {
+		ret = -BCH_ERR_ENOENT_not_subvol;
+		goto err;
+	}
+
+	if (deleting_snapshot || inode_u->bi_subvol) {
+		ret = bch2_subvolume_unlink(trans, inode_u->bi_subvol);
+		if (ret)
+			goto err;
+
+		k = bch2_btree_iter_peek_slot(&dirent_iter);
+		ret = bkey_err(k);
+		if (ret)
+			goto err;
+
+		/*
+		 * If we're deleting a subvolume, we need to really delete the
+		 * dirent, not just emit a whiteout in the current snapshot:
+		 */
+		bch2_btree_iter_set_snapshot(&dirent_iter, k.k->p.snapshot);
+		ret = bch2_btree_iter_traverse(&dirent_iter);
+		if (ret)
+			goto err;
+	} else {
+		bch2_inode_nlink_dec(trans, inode_u);
+	}
+
+	if (inode_u->bi_dir		== dirent_iter.pos.inode &&
+	    inode_u->bi_dir_offset	== dirent_iter.pos.offset) {
+		inode_u->bi_dir		= 0;
+		inode_u->bi_dir_offset	= 0;
+	}
+
+	dir_u->bi_mtime = dir_u->bi_ctime = inode_u->bi_ctime = now;
+	dir_u->bi_nlink -= is_subdir_for_nlink(inode_u);
+
+	ret =   bch2_hash_delete_at(trans, bch2_dirent_hash_desc,
+				    &dir_hash, &dirent_iter,
+				    BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE) ?:
+		bch2_inode_write(trans, &dir_iter, dir_u) ?:
+		bch2_inode_write(trans, &inode_iter, inode_u);
+err:
+	bch2_trans_iter_exit(trans, &inode_iter);
+	bch2_trans_iter_exit(trans, &dirent_iter);
+	bch2_trans_iter_exit(trans, &dir_iter);
+	return ret;
+}
+
+bool bch2_reinherit_attrs(struct bch_inode_unpacked *dst_u,
+			  struct bch_inode_unpacked *src_u)
+{
+	u64 src, dst;
+	unsigned id;
+	bool ret = false;
+
+	for (id = 0; id < Inode_opt_nr; id++) {
+		/* Skip attributes that were explicitly set on this inode */
+		if (dst_u->bi_fields_set & (1 << id))
+			continue;
+
+		src = bch2_inode_opt_get(src_u, id);
+		dst = bch2_inode_opt_get(dst_u, id);
+
+		if (src == dst)
+			continue;
+
+		bch2_inode_opt_set(dst_u, id, src);
+		ret = true;
+	}
+
+	return ret;
+}
+
+int bch2_rename_trans(struct btree_trans *trans,
+		      subvol_inum src_dir, struct bch_inode_unpacked *src_dir_u,
+		      subvol_inum dst_dir, struct bch_inode_unpacked *dst_dir_u,
+		      struct bch_inode_unpacked *src_inode_u,
+		      struct bch_inode_unpacked *dst_inode_u,
+		      const struct qstr *src_name,
+		      const struct qstr *dst_name,
+		      enum bch_rename_mode mode)
+{
+	struct bch_fs *c = trans->c;
+	struct btree_iter src_dir_iter = { NULL };
+	struct btree_iter dst_dir_iter = { NULL };
+	struct btree_iter src_inode_iter = { NULL };
+	struct btree_iter dst_inode_iter = { NULL };
+	struct bch_hash_info src_hash, dst_hash;
+	subvol_inum src_inum, dst_inum;
+	u64 src_offset, dst_offset;
+	u64 now = bch2_current_time(c);
+	int ret;
+
+	ret = bch2_inode_peek(trans, &src_dir_iter, src_dir_u, src_dir,
+			      BTREE_ITER_INTENT);
+	if (ret)
+		goto err;
+
+	src_hash = bch2_hash_info_init(c, src_dir_u);
+
+	if (dst_dir.inum	!= src_dir.inum ||
+	    dst_dir.subvol	!= src_dir.subvol) {
+		ret = bch2_inode_peek(trans, &dst_dir_iter, dst_dir_u, dst_dir,
+				      BTREE_ITER_INTENT);
+		if (ret)
+			goto err;
+
+		dst_hash = bch2_hash_info_init(c, dst_dir_u);
+	} else {
+		dst_dir_u = src_dir_u;
+		dst_hash = src_hash;
+	}
+
+	ret = bch2_dirent_rename(trans,
+				 src_dir, &src_hash,
+				 dst_dir, &dst_hash,
+				 src_name, &src_inum, &src_offset,
+				 dst_name, &dst_inum, &dst_offset,
+				 mode);
+	if (ret)
+		goto err;
+
+	ret = bch2_inode_peek(trans, &src_inode_iter, src_inode_u, src_inum,
+			      BTREE_ITER_INTENT);
+	if (ret)
+		goto err;
+
+	if (dst_inum.inum) {
+		ret = bch2_inode_peek(trans, &dst_inode_iter, dst_inode_u, dst_inum,
+				      BTREE_ITER_INTENT);
+		if (ret)
+			goto err;
+	}
+
+	if (c->sb.version >= bcachefs_metadata_version_inode_backpointers) {
+		src_inode_u->bi_dir		= dst_dir_u->bi_inum;
+		src_inode_u->bi_dir_offset	= dst_offset;
+
+		if (mode == BCH_RENAME_EXCHANGE) {
+			dst_inode_u->bi_dir		= src_dir_u->bi_inum;
+			dst_inode_u->bi_dir_offset	= src_offset;
+		}
+
+		if (mode == BCH_RENAME_OVERWRITE &&
+		    dst_inode_u->bi_dir		== dst_dir_u->bi_inum &&
+		    dst_inode_u->bi_dir_offset	== src_offset) {
+			dst_inode_u->bi_dir		= 0;
+			dst_inode_u->bi_dir_offset	= 0;
+		}
+	}
+
+	if (mode == BCH_RENAME_OVERWRITE) {
+		if (S_ISDIR(src_inode_u->bi_mode) !=
+		    S_ISDIR(dst_inode_u->bi_mode)) {
+			ret = -ENOTDIR;
+			goto err;
+		}
+
+		if (S_ISDIR(dst_inode_u->bi_mode) &&
+		    bch2_empty_dir_trans(trans, dst_inum)) {
+			ret = -ENOTEMPTY;
+			goto err;
+		}
+	}
+
+	if (bch2_reinherit_attrs(src_inode_u, dst_dir_u) &&
+	    S_ISDIR(src_inode_u->bi_mode)) {
+		ret = -EXDEV;
+		goto err;
+	}
+
+	if (mode == BCH_RENAME_EXCHANGE &&
+	    bch2_reinherit_attrs(dst_inode_u, src_dir_u) &&
+	    S_ISDIR(dst_inode_u->bi_mode)) {
+		ret = -EXDEV;
+		goto err;
+	}
+
+	if (is_subdir_for_nlink(src_inode_u)) {
+		src_dir_u->bi_nlink--;
+		dst_dir_u->bi_nlink++;
+	}
+
+	if (dst_inum.inum && is_subdir_for_nlink(dst_inode_u)) {
+		dst_dir_u->bi_nlink--;
+		src_dir_u->bi_nlink += mode == BCH_RENAME_EXCHANGE;
+	}
+
+	if (mode == BCH_RENAME_OVERWRITE)
+		bch2_inode_nlink_dec(trans, dst_inode_u);
+
+	src_dir_u->bi_mtime		= now;
+	src_dir_u->bi_ctime		= now;
+
+	if (src_dir.inum != dst_dir.inum) {
+		dst_dir_u->bi_mtime	= now;
+		dst_dir_u->bi_ctime	= now;
+	}
+
+	src_inode_u->bi_ctime		= now;
+
+	if (dst_inum.inum)
+		dst_inode_u->bi_ctime	= now;
+
+	ret =   bch2_inode_write(trans, &src_dir_iter, src_dir_u) ?:
+		(src_dir.inum != dst_dir.inum
+		 ? bch2_inode_write(trans, &dst_dir_iter, dst_dir_u)
+		 : 0) ?:
+		bch2_inode_write(trans, &src_inode_iter, src_inode_u) ?:
+		(dst_inum.inum
+		 ? bch2_inode_write(trans, &dst_inode_iter, dst_inode_u)
+		 : 0);
+err:
+	bch2_trans_iter_exit(trans, &dst_inode_iter);
+	bch2_trans_iter_exit(trans, &src_inode_iter);
+	bch2_trans_iter_exit(trans, &dst_dir_iter);
+	bch2_trans_iter_exit(trans, &src_dir_iter);
+	return ret;
+}