1 files changed, 178 insertions, 34 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index fce3b5b9a2bb..d96b2bc444c8 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1656,7 +1656,7 @@ static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
 
 		src_inode = file_inode(src.file);
 		if (src_inode->i_sb != file_inode(file)->i_sb) {
-			btrfs_info(BTRFS_I(src_inode)->root->fs_info,
+			btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
 				   "Snapshot src from another FS");
 			ret = -EXDEV;
 		} else if (!inode_owner_or_capable(src_inode)) {
@@ -2434,8 +2434,6 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 		goto out_unlock_inode;
 	}
 
-	d_invalidate(dentry);
-
 	down_write(&root->fs_info->subvol_sem);
 
 	err = may_destroy_subvol(dest);
@@ -2529,7 +2527,7 @@ out_up_write:
 out_unlock_inode:
 	mutex_unlock(&inode->i_mutex);
 	if (!err) {
-		shrink_dcache_sb(root->fs_info->sb);
+		d_invalidate(dentry);
 		btrfs_invalidate_inodes(dest);
 		d_delete(dentry);
 		ASSERT(dest->send_in_progress == 0);
@@ -2961,7 +2959,7 @@ out_unlock:
 static long btrfs_ioctl_file_extent_same(struct file *file,
 			struct btrfs_ioctl_same_args __user *argp)
 {
-	struct btrfs_ioctl_same_args *same;
+	struct btrfs_ioctl_same_args *same = NULL;
 	struct btrfs_ioctl_same_extent_info *info;
 	struct inode *src = file_inode(file);
 	u64 off;
@@ -2991,6 +2989,7 @@ static long btrfs_ioctl_file_extent_same(struct file *file,
 
 	if (IS_ERR(same)) {
 		ret = PTR_ERR(same);
+		same = NULL;
 		goto out;
 	}
 
@@ -3061,6 +3060,7 @@ static long btrfs_ioctl_file_extent_same(struct file *file,
 
 out:
 	mnt_drop_write_file(file);
+	kfree(same);
 	return ret;
 }
 
@@ -3187,6 +3187,150 @@ static void clone_update_extent_map(struct inode *inode,
 			&BTRFS_I(inode)->runtime_flags);
 }
 
+/*
+ * Make sure we do not end up inserting an inline extent into a file that has
+ * already other (non-inline) extents. If a file has an inline extent it can
+ * not have any other extents and the (single) inline extent must start at the
+ * file offset 0. Failing to respect these rules will lead to file corruption,
+ * resulting in EIO errors on read/write operations, hitting BUG_ON's in mm, etc
+ *
+ * We can have extents that have been already written to disk or we can have
+ * dirty ranges still in delalloc, in which case the extent maps and items are
+ * created only when we run delalloc, and the delalloc ranges might fall outside
+ * the range we are currently locking in the inode's io tree. So we check the
+ * inode's i_size because of that (i_size updates are done while holding the
+ * i_mutex, which we are holding here).
+ * We also check to see if the inode has a size not greater than "datal" but has
+ * extents beyond it, due to an fallocate with FALLOC_FL_KEEP_SIZE (and we are
+ * protected against such concurrent fallocate calls by the i_mutex).
+ *
+ * If the file has no extents but a size greater than datal, do not allow the
+ * copy because we would need turn the inline extent into a non-inline one (even
+ * with NO_HOLES enabled). If we find our destination inode only has one inline
+ * extent, just overwrite it with the source inline extent if its size is less
+ * than the source extent's size, or we could copy the source inline extent's
+ * data into the destination inode's inline extent if the later is greater then
+ * the former.
+ */
+static int clone_copy_inline_extent(struct inode *src,
+				    struct inode *dst,
+				    struct btrfs_trans_handle *trans,
+				    struct btrfs_path *path,
+				    struct btrfs_key *new_key,
+				    const u64 drop_start,
+				    const u64 datal,
+				    const u64 skip,
+				    const u64 size,
+				    char *inline_data)
+{
+	struct btrfs_root *root = BTRFS_I(dst)->root;
+	const u64 aligned_end = ALIGN(new_key->offset + datal,
+				      root->sectorsize);
+	int ret;
+	struct btrfs_key key;
+
+	if (new_key->offset > 0)
+		return -EOPNOTSUPP;
+
+	key.objectid = btrfs_ino(dst);
+	key.type = BTRFS_EXTENT_DATA_KEY;
+	key.offset = 0;
+	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+	if (ret < 0) {
+		return ret;
+	} else if (ret > 0) {
+		if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
+			ret = btrfs_next_leaf(root, path);
+			if (ret < 0)
+				return ret;
+			else if (ret > 0)
+				goto copy_inline_extent;
+		}
+		btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
+		if (key.objectid == btrfs_ino(dst) &&
+		    key.type == BTRFS_EXTENT_DATA_KEY) {
+			ASSERT(key.offset > 0);
+			return -EOPNOTSUPP;
+		}
+	} else if (i_size_read(dst) <= datal) {
+		struct btrfs_file_extent_item *ei;
+		u64 ext_len;
+
+		/*
+		 * If the file size is <= datal, make sure there are no other
+		 * extents following (can happen do to an fallocate call with
+		 * the flag FALLOC_FL_KEEP_SIZE).
+		 */
+		ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
+				    struct btrfs_file_extent_item);
+		/*
+		 * If it's an inline extent, it can not have other extents
+		 * following it.
+		 */
+		if (btrfs_file_extent_type(path->nodes[0], ei) ==
+		    BTRFS_FILE_EXTENT_INLINE)
+			goto copy_inline_extent;
+
+		ext_len = btrfs_file_extent_num_bytes(path->nodes[0], ei);
+		if (ext_len > aligned_end)
+			return -EOPNOTSUPP;
+
+		ret = btrfs_next_item(root, path);
+		if (ret < 0) {
+			return ret;
+		} else if (ret == 0) {
+			btrfs_item_key_to_cpu(path->nodes[0], &key,
+					      path->slots[0]);
+			if (key.objectid == btrfs_ino(dst) &&
+			    key.type == BTRFS_EXTENT_DATA_KEY)
+				return -EOPNOTSUPP;
+		}
+	}
+
+copy_inline_extent:
+	/*
+	 * We have no extent items, or we have an extent at offset 0 which may
+	 * or may not be inlined. All these cases are dealt the same way.
+	 */
+	if (i_size_read(dst) > datal) {
+		/*
+		 * If the destination inode has an inline extent...
+		 * This would require copying the data from the source inline
+		 * extent into the beginning of the destination's inline extent.
+		 * But this is really complex, both extents can be compressed
+		 * or just one of them, which would require decompressing and
+		 * re-compressing data (which could increase the new compressed
+		 * size, not allowing the compressed data to fit anymore in an
+		 * inline extent).
+		 * So just don't support this case for now (it should be rare,
+		 * we are not really saving space when cloning inline extents).
+		 */
+		return -EOPNOTSUPP;
+	}
+
+	btrfs_release_path(path);
+	ret = btrfs_drop_extents(trans, root, dst, drop_start, aligned_end, 1);
+	if (ret)
+		return ret;
+	ret = btrfs_insert_empty_item(trans, root, path, new_key, size);
+	if (ret)
+		return ret;
+
+	if (skip) {
+		const u32 start = btrfs_file_extent_calc_inline_size(0);
+
+		memmove(inline_data + start, inline_data + start + skip, datal);
+	}
+
+	write_extent_buffer(path->nodes[0], inline_data,
+			    btrfs_item_ptr_offset(path->nodes[0],
+						  path->slots[0]),
+			    size);
+	inode_add_bytes(dst, datal);
+
+	return 0;
+}
+
 /**
  * btrfs_clone() - clone a range from inode file to another
  *
@@ -3451,7 +3595,6 @@ process_slot:
 			} else if (type == BTRFS_FILE_EXTENT_INLINE) {
 				u64 skip = 0;
 				u64 trim = 0;
-				u64 aligned_end = 0;
 
 				if (off > key.offset) {
 					skip = off - key.offset;
@@ -3469,42 +3612,22 @@ process_slot:
 				size -= skip + trim;
 				datal -= skip + trim;
 
-				aligned_end = ALIGN(new_key.offset + datal,
-						    root->sectorsize);
-				ret = btrfs_drop_extents(trans, root, inode,
-							 drop_start,
-							 aligned_end,
-							 1);
+				ret = clone_copy_inline_extent(src, inode,
+							       trans, path,
+							       &new_key,
+							       drop_start,
+							       datal,
+							       skip, size, buf);
 				if (ret) {
 					if (ret != -EOPNOTSUPP)
 						btrfs_abort_transaction(trans,
-							root, ret);
-					btrfs_end_transaction(trans, root);
-					goto out;
-				}
-
-				ret = btrfs_insert_empty_item(trans, root, path,
-							      &new_key, size);
-				if (ret) {
-					btrfs_abort_transaction(trans, root,
-								ret);
+									root,
+									ret);
 					btrfs_end_transaction(trans, root);
 					goto out;
 				}
-
-				if (skip) {
-					u32 start =
-					  btrfs_file_extent_calc_inline_size(0);
-					memmove(buf+start, buf+start+skip,
-						datal);
-				}
-
 				leaf = path->nodes[0];
 				slot = path->slots[0];
-				write_extent_buffer(leaf, buf,
-					    btrfs_item_ptr_offset(leaf, slot),
-					    size);
-				inode_add_bytes(inode, datal);
 			}
 
 			/* If we have an implicit hole (NO_HOLES feature). */
@@ -5372,3 +5495,24 @@ long btrfs_ioctl(struct file *file, unsigned int
 
 	return -ENOTTY;
 }
+
+#ifdef CONFIG_COMPAT
+long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	switch (cmd) {
+	case FS_IOC32_GETFLAGS:
+		cmd = FS_IOC_GETFLAGS;
+		break;
+	case FS_IOC32_SETFLAGS:
+		cmd = FS_IOC_SETFLAGS;
+		break;
+	case FS_IOC32_GETVERSION:
+		cmd = FS_IOC_GETVERSION;
+		break;
+	default:
+		return -ENOIOCTLCMD;
+	}
+
+	return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
+}
+#endif