Support O_TMPFILE and allow MOVE_BLOCKS into released extents

Support O_TMPFILE: Create an unlinked file and put it on the orphan list.
If it ever gains a link, take it off the orphan list.

Change MOVE_BLOCKS ioctl to allow moving blocks into offline extent ranges.
Ioctl callers must set a new flag to enable this operation mode.

RH-compat: tmpfile support it actually backported by RH into 3.10 kernel.
We need to use some of their kabi-maintaining wrappers to use it:
use a struct inode_operations_wrapper instead of base struct
inode_operations, set S_IOPS_WRAPPER flag in i_flags. This lets
RH's modified vfs_tmpfile() find our tmpfile fn pointer.

Add a test that tests both creating tmpfiles as well as moving their
contents into a destination file via MOVE_BLOCKS.

xfstests common/004 now runs because tmpfile is supported.

Signed-off-by: Andy Grover <agrover@versity.com>

kmod/src/data.c

@@ -1135,7 +1135,8 @@ static void truncate_inode_pages_extent(struct inode *inode, u64 start, u64 len)
  */
 #define MOVE_DATA_EXTENTS_PER_HOLD 16
 int scoutfs_data_move_blocks(struct inode *from, u64 from_off,
-			     u64 byte_len, struct inode *to, u64 to_off)
+			     u64 byte_len, struct inode *to, u64 to_off, bool is_stage,
+			     u64 data_version)
 {
 	struct scoutfs_inode_info *from_si = SCOUTFS_I(from);
 	struct scoutfs_inode_info *to_si = SCOUTFS_I(to);
@@ -1145,6 +1146,7 @@ int scoutfs_data_move_blocks(struct inode *from, u64 from_off,
 	struct data_ext_args from_args;
 	struct data_ext_args to_args;
 	struct scoutfs_extent ext;
+	struct timespec cur_time;
 	LIST_HEAD(locks);
 	bool done = false;
 	loff_t from_size;
@@ -1180,6 +1182,11 @@ int scoutfs_data_move_blocks(struct inode *from, u64 from_off,
 		goto out;
 	}
 
+	if (is_stage && (data_version != SCOUTFS_I(to)->data_version)) {
+		ret = -ESTALE;
+		goto out;
+	}
+
 	from_iblock = from_off >> SCOUTFS_BLOCK_SM_SHIFT;
 	count = (byte_len + SCOUTFS_BLOCK_SM_MASK) >> SCOUTFS_BLOCK_SM_SHIFT;
 	to_iblock = to_off >> SCOUTFS_BLOCK_SM_SHIFT;
@@ -1202,7 +1209,7 @@ int scoutfs_data_move_blocks(struct inode *from, u64 from_off,
 	/* can't stage once data_version changes */
 	scoutfs_inode_get_onoff(from, &junk, &from_offline);
 	scoutfs_inode_get_onoff(to, &junk, &to_offline);
-	if (from_offline || to_offline) {
+	if (from_offline || (to_offline && !is_stage)) {
 		ret = -ENODATA;
 		goto out;
 	}
@@ -1246,6 +1253,8 @@ int scoutfs_data_move_blocks(struct inode *from, u64 from_off,
 
 		/* arbitrarily limit the number of extents per trans hold */
 		for (i = 0; i < MOVE_DATA_EXTENTS_PER_HOLD; i++) {
+			struct scoutfs_extent off_ext;
+
 			/* find the next extent to move */
 			ret = scoutfs_ext_next(sb, &data_ext_ops, &from_args,
 					       from_iblock, 1, &ext);
@@ -1274,10 +1283,27 @@ int scoutfs_data_move_blocks(struct inode *from, u64 from_off,
 
 			to_start = to_iblock + (from_start - from_iblock);
 
-			/* insert the new, fails if it overlaps */
-			ret = scoutfs_ext_insert(sb, &data_ext_ops, &to_args,
-						 to_start, len,
-						 map, ext.flags);
+			if (is_stage) {
+				ret = scoutfs_ext_next(sb, &data_ext_ops, &to_args,
+						       to_iblock, 1, &off_ext);
+				if (ret)
+					break;
+
+				if (!scoutfs_ext_inside(to_start, len, &off_ext) ||
+				    !(off_ext.flags & SEF_OFFLINE)) {
+					ret = -EINVAL;
+					break;
+				}
+
+				ret = scoutfs_ext_set(sb, &data_ext_ops, &to_args,
+							 to_start, len,
+							 map, ext.flags);
+			} else {
+				/* insert the new, fails if it overlaps */
+				ret = scoutfs_ext_insert(sb, &data_ext_ops, &to_args,
+							 to_start, len,
+							 map, ext.flags);
+			}
 			if (ret < 0)
 				break;
 
@@ -1285,10 +1311,18 @@ int scoutfs_data_move_blocks(struct inode *from, u64 from_off,
 			ret = scoutfs_ext_set(sb, &data_ext_ops, &from_args,
 					      from_start, len, 0, 0);
 			if (ret < 0) {
-				/* remove inserted new on err */
-				err = scoutfs_ext_remove(sb, &data_ext_ops,
-							 &to_args, to_start,
-							 len);
+				if (is_stage) {
+					/* re-mark dest range as offline */
+					WARN_ON_ONCE(!(off_ext.flags & SEF_OFFLINE));
+					err = scoutfs_ext_set(sb, &data_ext_ops, &to_args,
+							      to_start, len,
+							      0, off_ext.flags);
+				} else {
+					/* remove inserted new on err */
+					err = scoutfs_ext_remove(sb, &data_ext_ops,
+								 &to_args, to_start,
+								 len);
+				}
 				BUG_ON(err); /* XXX inconsistent */
 				break;
 			}
@@ -1316,12 +1350,15 @@ int scoutfs_data_move_blocks(struct inode *from, u64 from_off,
 		up_write(&from_si->extent_sem);
 		up_write(&to_si->extent_sem);
 
-		from->i_ctime = from->i_mtime =
-			to->i_ctime = to->i_mtime = CURRENT_TIME;
+		cur_time = CURRENT_TIME;
+		if (!is_stage) {
+			to->i_ctime = to->i_mtime = cur_time;
+			scoutfs_inode_inc_data_version(to);
+			scoutfs_inode_set_data_seq(to);
+		}
+		from->i_ctime = from->i_mtime = cur_time;
 		scoutfs_inode_inc_data_version(from);
-		scoutfs_inode_inc_data_version(to);
 		scoutfs_inode_set_data_seq(from);
-		scoutfs_inode_set_data_seq(to);
 
 		scoutfs_update_inode_item(from, from_lock, &locks);
 		scoutfs_update_inode_item(to, to_lock, &locks);

kmod/src/data.h

@@ -59,7 +59,8 @@ long scoutfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len);
 int scoutfs_data_init_offline_extent(struct inode *inode, u64 size,
 				     struct scoutfs_lock *lock);
 int scoutfs_data_move_blocks(struct inode *from, u64 from_off,
-			     u64 byte_len, struct inode *to, u64 to_off);
+			     u64 byte_len, struct inode *to, u64 to_off, bool to_stage,
+			     u64 data_version);
 
 int scoutfs_data_wait_check(struct inode *inode, loff_t pos, loff_t len,
 			    u8 sef, u8 op, struct scoutfs_data_wait *ow,

kmod/src/dir.c

@@ -813,6 +813,7 @@ static int scoutfs_link(struct dentry *old_dentry,
 	struct scoutfs_lock *dir_lock;
 	struct scoutfs_lock *inode_lock = NULL;
 	LIST_HEAD(ind_locks);
+	bool del_orphan;
 	u64 dir_size;
 	u64 ind_seq;
 	u64 hash;
@@ -841,6 +842,8 @@ static int scoutfs_link(struct dentry *old_dentry,
 		goto out_unlock;
 
 	dir_size = i_size_read(dir) + dentry->d_name.len;
+	del_orphan = (inode->i_nlink == 0);
+
 retry:
 	ret = scoutfs_inode_index_start(sb, &ind_seq) ?:
 	      scoutfs_inode_index_prepare(sb, &ind_locks, dir, false) ?:
@@ -855,6 +858,12 @@ retry:
 	if (ret)
 		goto out;
 
+	if (del_orphan) {
+		ret = scoutfs_orphan_dirty(sb, scoutfs_ino(inode));
+		if (ret)
+			goto out;
+	}
+
 	pos = SCOUTFS_I(dir)->next_readdir_pos++;
 
 	ret = add_entry_items(sb, scoutfs_ino(dir), hash, pos,
@@ -870,6 +879,11 @@ retry:
 	inode->i_ctime = dir->i_mtime;
 	inc_nlink(inode);
 
+	if (del_orphan) {
+		ret = scoutfs_orphan_delete(sb, scoutfs_ino(inode));
+		WARN_ON_ONCE(ret);
+	}
+
 	scoutfs_update_inode_item(inode, inode_lock, &ind_locks);
 	scoutfs_update_inode_item(dir, dir_lock, &ind_locks);
 
@@ -1760,6 +1774,42 @@ static int scoutfs_dir_open(struct inode *inode, struct file *file)
 }
 #endif
 
+static int scoutfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
+{
+	struct super_block *sb = dir->i_sb;
+	struct inode *inode = NULL;
+	struct scoutfs_lock *dir_lock = NULL;
+	struct scoutfs_lock *inode_lock = NULL;
+	LIST_HEAD(ind_locks);
+	int ret;
+
+	if (dentry->d_name.len > SCOUTFS_NAME_LEN)
+		return -ENAMETOOLONG;
+
+	inode = lock_hold_create(dir, dentry, mode, 0,
+				 &dir_lock, &inode_lock, &ind_locks);
+	if (IS_ERR(inode))
+		return PTR_ERR(inode);
+
+	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
+	insert_inode_hash(inode);
+	d_tmpfile(dentry, inode);
+
+	scoutfs_update_inode_item(inode, inode_lock, &ind_locks);
+	scoutfs_update_inode_item(dir, dir_lock, &ind_locks);
+	scoutfs_inode_index_unlock(sb, &ind_locks);
+
+	ret = scoutfs_orphan_inode(inode);
+	WARN_ON_ONCE(ret); /* XXX returning error but items deleted */
+
+	scoutfs_release_trans(sb);
+	scoutfs_inode_index_unlock(sb, &ind_locks);
+	scoutfs_unlock(sb, dir_lock, SCOUTFS_LOCK_WRITE);
+	scoutfs_unlock(sb, inode_lock, SCOUTFS_LOCK_WRITE);
+
+	return ret;
+}
+
 const struct file_operations scoutfs_dir_fops = {
 	.KC_FOP_READDIR	= scoutfs_readdir,
 #ifdef KC_FMODE_KABI_ITERATE
@@ -1770,7 +1820,10 @@ const struct file_operations scoutfs_dir_fops = {
 	.llseek		= generic_file_llseek,
 };
 
-const struct inode_operations scoutfs_dir_iops = {
+
+
+const struct inode_operations_wrapper scoutfs_dir_iops = {
+	.ops = {
 	.lookup		= scoutfs_lookup,
 	.mknod		= scoutfs_mknod,
 	.create		= scoutfs_create,
@@ -1787,6 +1840,8 @@ const struct inode_operations scoutfs_dir_iops = {
 	.removexattr	= scoutfs_removexattr,
 	.symlink	= scoutfs_symlink,
 	.permission	= scoutfs_permission,
+	},
+	.tmpfile	= scoutfs_tmpfile,
 };
 
 void scoutfs_dir_exit(void)

kmod/src/dir.h

@@ -5,7 +5,7 @@
 #include "lock.h"
 
 extern const struct file_operations scoutfs_dir_fops;
-extern const struct inode_operations scoutfs_dir_iops;
+extern const struct inode_operations_wrapper scoutfs_dir_iops;
 extern const struct inode_operations scoutfs_symlink_iops;
 
 struct scoutfs_link_backref_entry {

kmod/src/ext.c

@@ -38,7 +38,7 @@ static bool ext_overlap(struct scoutfs_extent *ext, u64 start, u64 len)
 	return !(e_end < start || ext->start > end);
 }
 
-static bool ext_inside(u64 start, u64 len, struct scoutfs_extent *out)
+bool scoutfs_ext_inside(u64 start, u64 len, struct scoutfs_extent *out)
 {
 	u64 in_end = start + len - 1;
 	u64 out_end = out->start + out->len - 1;
@@ -241,7 +241,7 @@ int scoutfs_ext_remove(struct super_block *sb, struct scoutfs_ext_ops *ops,
 		goto out;
 
 	/* removed extent must be entirely within found */
-	if (!ext_inside(start, len, &found)) {
+	if (!scoutfs_ext_inside(start, len, &found)) {
 		ret = -EINVAL;
 		goto out;
 	}
@@ -341,7 +341,7 @@ int scoutfs_ext_set(struct super_block *sb, struct scoutfs_ext_ops *ops,
 
 	if (ret == 0 && ext_overlap(&found, start, len)) {
 		/* set extent must be entirely within found */
-		if (!ext_inside(start, len, &found)) {
+		if (!scoutfs_ext_inside(start, len, &found)) {
 			ret = -EINVAL;
 			goto out;
 		}

kmod/src/ext.h

@@ -31,5 +31,6 @@ int scoutfs_ext_alloc(struct super_block *sb, struct scoutfs_ext_ops *ops,
 		      struct scoutfs_extent *ext);
 int scoutfs_ext_set(struct super_block *sb, struct scoutfs_ext_ops *ops,
 		    void *arg, u64 start, u64 len, u64 map, u8 flags);
+bool scoutfs_ext_inside(u64 start, u64 len, struct scoutfs_extent *out);
 
 #endif

kmod/src/inode.c

@@ -182,7 +182,8 @@ static void set_inode_ops(struct inode *inode)
 		inode->i_fop = &scoutfs_file_fops;
 		break;
 	case S_IFDIR:
-		inode->i_op = &scoutfs_dir_iops;
+		inode->i_op = &scoutfs_dir_iops.ops;
+		inode->i_flags |= S_IOPS_WRAPPER;
 		inode->i_fop = &scoutfs_dir_fops;
 		break;
 	case S_IFLNK:
@@ -1417,7 +1418,18 @@ static void init_orphan_key(struct scoutfs_key *key, u64 rid, u64 ino)
 	};
 }
 
-static int remove_orphan_item(struct super_block *sb, u64 ino)
+int scoutfs_orphan_dirty(struct super_block *sb, u64 ino)
+{
+	struct scoutfs_sb_info *sbi = SCOUTFS_SB(sb);
+	struct scoutfs_lock *lock = sbi->rid_lock;
+	struct scoutfs_key key;
+
+	init_orphan_key(&key, sbi->rid, ino);
+
+	return scoutfs_item_dirty(sb, &key, lock);
+}
+
+int scoutfs_orphan_delete(struct super_block *sb, u64 ino)
 {
 	struct scoutfs_sb_info *sbi = SCOUTFS_SB(sb);
 	struct scoutfs_lock *lock = sbi->rid_lock;
@@ -1516,7 +1528,7 @@ retry:
 	if (ret)
 		goto out;
 
-	ret = remove_orphan_item(sb, ino);
+	ret = scoutfs_orphan_delete(sb, ino);
 out:
 	if (release)
 		scoutfs_release_trans(sb);

kmod/src/inode.h

@@ -114,6 +114,8 @@ int scoutfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
 int scoutfs_setattr(struct dentry *dentry, struct iattr *attr);
 
 int scoutfs_scan_orphans(struct super_block *sb);
+int scoutfs_orphan_dirty(struct super_block *sb, u64 ino);
+int scoutfs_orphan_delete(struct super_block *sb, u64 ino);
 
 void scoutfs_inode_queue_writeback(struct inode *inode);
 int scoutfs_inode_walk_writeback(struct super_block *sb, bool write);

kmod/src/ioctl.c

@@ -972,12 +972,18 @@ static long scoutfs_ioc_move_blocks(struct file *file, unsigned long arg)
 		goto out;
 	}
 
+	if (mb.flags & SCOUTFS_IOC_MB_UNKNOWN) {
+		ret = -EINVAL;
+		goto out;
+	}
+
 	ret = mnt_want_write_file(file);
 	if (ret < 0)
 		goto out;
 
 	ret = scoutfs_data_move_blocks(from, mb.from_off, mb.len,
-				       to, mb.to_off);
+				       to, mb.to_off, !!(mb.flags & SCOUTFS_IOC_MB_STAGE),
+				       mb.data_version);
 	mnt_drop_write_file(file);
 out:
 	fput(from_file);

kmod/src/ioctl.h

@@ -259,7 +259,7 @@ struct scoutfs_ioctl_data_waiting {
 	__u8 _pad[6];
 };
 
-#define SCOUTFS_IOC_DATA_WAITING_FLAGS_UNKNOWN		(U8_MAX << 0)
+#define SCOUTFS_IOC_DATA_WAITING_FLAGS_UNKNOWN		(U64_MAX << 0)
 
 #define SCOUTFS_IOC_DATA_WAITING _IOR(SCOUTFS_IOCTL_MAGIC, 6, \
 				      struct scoutfs_ioctl_data_waiting)
@@ -279,7 +279,7 @@ struct scoutfs_ioctl_setattr_more {
 };
 
 #define SCOUTFS_IOC_SETATTR_MORE_OFFLINE		(1 << 0)
-#define SCOUTFS_IOC_SETATTR_MORE_UNKNOWN		(U8_MAX << 1)
+#define SCOUTFS_IOC_SETATTR_MORE_UNKNOWN		(U64_MAX << 1)
 
 #define SCOUTFS_IOC_SETATTR_MORE _IOW(SCOUTFS_IOCTL_MAGIC, 7, \
 				      struct scoutfs_ioctl_setattr_more)
@@ -418,12 +418,13 @@ struct scoutfs_ioctl_alloc_detail_entry {
  * on the same file system.
  *
  * from_fd specifies the source file and the ioctl is called on the
- * destination file.  Both files must have write access.  from_off
- * specifies the byte offset in the source, to_off is the byte offset in
- * the destination, and len is the number of bytes in the region to
- * move.   All of the offsets and lengths must be in multiples of 4KB,
- * except in the case where the from_off + len ends at the i_size of the
- * source file.
+ * destination file.  Both files must have write access.  from_off specifies
+ * the byte offset in the source, to_off is the byte offset in the
+ * destination, and len is the number of bytes in the region to move.  All of
+ * the offsets and lengths must be in multiples of 4KB, except in the case
+ * where the from_off + len ends at the i_size of the source
+ * file. data_version is only used when STAGE flag is set (see below).  flags
+ * field is currently only used to optionally specify STAGE behavior.
  *
  * This interface only moves extents which are block granular, it does
  * not perform RMW of sub-block byte extents and it does not overwrite
@@ -435,30 +436,41 @@ struct scoutfs_ioctl_alloc_detail_entry {
  * i_size.  The i_size update will maintain final partial blocks in the
  * source.
  *
- * It will return an error if either of the files have offline extents.
- * It will return 0 when all of the extents in the source region have
- * been moved to the destination.  Moving extents updates the ctime,
- * mtime, meta_seq, data_seq, and data_version fields of both the source
- * and destination inodes.  If an error is returned then partial
+ * If STAGE flag is not set, it will return an error if either of the files
+ * have offline extents.  It will return 0 when all of the extents in the
+ * source region have been moved to the destination.  Moving extents updates
+ * the ctime, mtime, meta_seq, data_seq, and data_version fields of both the
+ * source and destination inodes.  If an error is returned then partial
  * progress may have been made and inode fields may have been updated.
  *
+ * If STAGE flag is set, as above except destination range must be in an
+ * offline extent. Fields are updated only for source inode.
+ *
  * Errors specific to this interface include:
  *
  * EINVAL: from_off, len, or to_off aren't a multiple of 4KB; the source
  *	   and destination files are the same inode; either the source or
  *	   destination is not a regular file; the destination file has
- *	   an existing overlapping extent.
+ *	   an existing overlapping extent (if STAGE flag not set); the
+ *	   destination range is not in an offline extent (if STAGE set).
  * EOVERFLOW: either from_off + len or to_off + len exceeded 64bits.
  * EBADF: from_fd isn't a valid open file descriptor.
  * EXDEV: the source and destination files are in different filesystems.
  * EISDIR: either the source or destination is a directory.
- * ENODATA: either the source or destination file have offline extents.
+ * ENODATA: either the source or destination file have offline extents and
+ *	    STAGE flag is not set.
+ * ESTALE: data_version does not match destination data_version.
  */
+#define SCOUTFS_IOC_MB_STAGE		(1 << 0)
+#define SCOUTFS_IOC_MB_UNKNOWN		(U64_MAX << 1)
+
 struct scoutfs_ioctl_move_blocks {
 	__u64 from_fd;
 	__u64 from_off;
 	__u64 len;
 	__u64 to_off;
+	__u64 data_version;
+	__u64 flags;
 };
 
 #define SCOUTFS_IOC_MOVE_BLOCKS _IOR(SCOUTFS_IOCTL_MAGIC, 13, \