[PATCH v2 3/5] btrfs: use I_VERITY_BUILDING instead of private flags

[Andrey Albershteyn <aalbersh@kernel.org>]

Now that the VFS tracks an inode whose Merkle tree is under construction
via I_VERITY_BUILDING and handles the concurrent-enable guard in the
generic fs-verity enable path, drop the inode runtime flags that
duplicated this.

btrfs only used BTRFS_INODE_VERITY_IN_PROGRESS internally, so remove it
outright.

Signed-off-by: Andrey Albershteyn <aalbersh@kernel.org>
---
 fs/btrfs/btrfs_inode.h |  7 -------
 fs/btrfs/verity.c      | 14 +++-----------
 2 files changed, 3 insertions(+), 18 deletions(-)

diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index 0782f917fccc..5c752b947b56 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -78,13 +78,6 @@ enum {
 	 * the file range, inode's io_tree).
 	 */
 	BTRFS_INODE_NO_DELALLOC_FLUSH,
-	/*
-	 * Set when we are working on enabling verity for a file. Computing and
-	 * writing the whole Merkle tree can take a while so we want to prevent
-	 * races where two separate tasks attempt to simultaneously start verity
-	 * on the same file.
-	 */
-	BTRFS_INODE_VERITY_IN_PROGRESS,
 	/* Set when this inode is a free space inode. */
 	BTRFS_INODE_FREE_SPACE_INODE,
 	/* Set when there are no capabilities in XATTs for the inode. */
diff --git a/fs/btrfs/verity.c b/fs/btrfs/verity.c
index b34d2247cf84..c7eec8886e49 100644
--- a/fs/btrfs/verity.c
+++ b/fs/btrfs/verity.c
@@ -461,7 +461,6 @@ static int rollback_verity(struct btrfs_inode *inode)
 
 	btrfs_assert_inode_locked(inode);
 	truncate_inode_pages(inode->vfs_inode.i_mapping, inode->vfs_inode.i_size);
-	clear_bit(BTRFS_INODE_VERITY_IN_PROGRESS, &inode->runtime_flags);
 	ret = btrfs_drop_verity_items(inode);
 	if (ret) {
 		btrfs_handle_fs_error(root->fs_info, ret,
@@ -513,7 +512,6 @@ static int rollback_verity(struct btrfs_inode *inode)
  * - mark the inode with the verity flag
  * - delete the orphan item
  * - mark the ro compat bit
- * - clear the in progress bit
  *
  * Returns 0 on success, negative error code on failure.
  */
@@ -555,7 +553,6 @@ static int finish_verity(struct btrfs_inode *inode, const void *desc,
 		goto end_trans;
 	/* Now that rollback is no longer possible, set S_VERITY. */
 	btrfs_sync_inode_flags_to_i_flags(inode);
-	clear_bit(BTRFS_INODE_VERITY_IN_PROGRESS, &inode->runtime_flags);
 	btrfs_set_fs_compat_ro(root->fs_info, VERITY);
 end_trans:
 	if (ret)
@@ -570,8 +567,8 @@ static int finish_verity(struct btrfs_inode *inode, const void *desc,
  *
  * @filp:  file to enable verity on
  *
- * Begin enabling fsverity for the file. We drop any existing verity items, add
- * an orphan and set the in progress bit.
+ * Begin enabling fsverity for the file. We drop any existing verity items and
+ * add an orphan.
  *
  * Returns 0 on success, negative error code on failure.
  */
@@ -587,9 +584,6 @@ static int btrfs_begin_enable_verity(struct file *filp)
 	if (IS_ENCRYPTED(&inode->vfs_inode))
 		return -EOPNOTSUPP;
 
-	if (test_bit(BTRFS_INODE_VERITY_IN_PROGRESS, &inode->runtime_flags))
-		return -EBUSY;
-
 	/*
 	 * This should almost never do anything, but theoretically, it's
 	 * possible that we failed to enable verity on a file, then were
@@ -606,11 +600,9 @@ static int btrfs_begin_enable_verity(struct file *filp)
 		return PTR_ERR(trans);
 
 	ret = btrfs_orphan_add(trans, inode);
-	if (!ret)
-		set_bit(BTRFS_INODE_VERITY_IN_PROGRESS, &inode->runtime_flags);
 	btrfs_end_transaction(trans);
 
-	return 0;
+	return ret;
 }
 
 /*
-- 
2.54.0