[PATCH v5 33/52] btrfs: populate ordered_extent with the orig offset

[Josef Bacik <josef@toxicpanda.com>]

For extent encryption we have to use a logical block nr as input for the
IV.  For btrfs we're using the offset into the extent we're operating
on.  For most ordered extents this is the same as the file_offset,
however for prealloc and NOCOW we have to use the original offset.

Add this as an argument and plumb it through everywhere, this will be
used when setting up the bio.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/inode.c        | 15 ++++++++++-----
 fs/btrfs/ordered-data.c | 32 ++++++++++++++++++++++----------
 fs/btrfs/ordered-data.h | 12 +++++++++---
 3 files changed, 41 insertions(+), 18 deletions(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 71098063bb9f..a84ff55b7eb5 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1175,6 +1175,7 @@ static void submit_one_async_extent(struct async_chunk *async_chunk,
 
 	ordered = btrfs_alloc_ordered_extent(inode, em->fscrypt_info,
 				       start,			/* file_offset */
+				       start,			/* orig_start */
 				       async_extent->ram_size,	/* num_bytes */
 				       async_extent->ram_size,	/* ram_bytes */
 				       ins.objectid,		/* disk_bytenr */
@@ -1438,8 +1439,8 @@ static noinline int cow_file_range(struct btrfs_inode *inode,
 		}
 
 		ordered = btrfs_alloc_ordered_extent(inode, em->fscrypt_info,
-					start, ram_size, ram_size, ins.objectid,
-					cur_alloc_size, 0,
+					start, start, ram_size, ram_size,
+					ins.objectid, cur_alloc_size, 0,
 					1 << BTRFS_ORDERED_REGULAR,
 					BTRFS_COMPRESS_NONE);
 		free_extent_map(em);
@@ -2193,7 +2194,9 @@ static noinline int run_delalloc_nocow(struct btrfs_inode *inode,
 		}
 
 		ordered = btrfs_alloc_ordered_extent(inode, fscrypt_info,
-				cur_offset, nocow_args.num_bytes,
+				cur_offset,
+				found_key.offset - nocow_args.extent_offset,
+				nocow_args.num_bytes,
 				nocow_args.num_bytes, nocow_args.disk_bytenr,
 				nocow_args.num_bytes, 0,
 				is_prealloc
@@ -7117,8 +7120,9 @@ static struct extent_map *btrfs_create_dio_extent(struct btrfs_inode *inode,
 		fscrypt_info = em->fscrypt_info;
 	}
 
-	ordered = btrfs_alloc_ordered_extent(inode, fscrypt_info, start, len,
-					     len, block_start, block_len, 0,
+	ordered = btrfs_alloc_ordered_extent(inode, fscrypt_info, start,
+					     orig_start, len, len, block_start,
+					     block_len, 0,
 					     (1 << type) |
 					     (1 << BTRFS_ORDERED_DIRECT),
 					     BTRFS_COMPRESS_NONE);
@@ -10684,6 +10688,7 @@ ssize_t btrfs_do_encoded_write(struct kiocb *iocb, struct iov_iter *from,
 	}
 
 	ordered = btrfs_alloc_ordered_extent(inode, em->fscrypt_info, start,
+				       start - encoded->unencoded_offset,
 				       num_bytes, ram_bytes, ins.objectid,
 				       ins.offset, encoded->unencoded_offset,
 				       (1 << BTRFS_ORDERED_ENCODED) |
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index 1cd04c57b7a2..c33012ec79d9 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -148,9 +148,9 @@ static inline struct rb_node *ordered_tree_search(struct btrfs_inode *inode,
 static struct btrfs_ordered_extent *alloc_ordered_extent(
 			struct btrfs_inode *inode,
 			struct fscrypt_extent_info *fscrypt_info,
-			u64 file_offset, u64 num_bytes, u64 ram_bytes,
-			u64 disk_bytenr, u64 disk_num_bytes, u64 offset,
-			unsigned long flags, int compress_type)
+			u64 file_offset, u64 orig_offset, u64 num_bytes,
+			u64 ram_bytes, u64 disk_bytenr, u64 disk_num_bytes,
+			u64 offset, unsigned long flags, int compress_type)
 {
 	struct btrfs_ordered_extent *entry;
 	int ret;
@@ -176,6 +176,7 @@ static struct btrfs_ordered_extent *alloc_ordered_extent(
 		return ERR_PTR(-ENOMEM);
 
 	entry->file_offset = file_offset;
+	entry->orig_offset = orig_offset;
 	entry->num_bytes = num_bytes;
 	entry->ram_bytes = ram_bytes;
 	entry->disk_bytenr = disk_bytenr;
@@ -254,6 +255,7 @@ static void insert_ordered_extent(struct btrfs_ordered_extent *entry)
  * @inode:           Inode that this extent is for.
  * @fscrypt_info:    The fscrypt_extent_info for this extent, if necessary.
  * @file_offset:     Logical offset in file where the extent starts.
+ * @orig_offset:     Logical offset of the original extent (PREALLOC or NOCOW)
  * @num_bytes:       Logical length of extent in file.
  * @ram_bytes:       Full length of unencoded data.
  * @disk_bytenr:     Offset of extent on disk.
@@ -271,17 +273,17 @@ static void insert_ordered_extent(struct btrfs_ordered_extent *entry)
 struct btrfs_ordered_extent *btrfs_alloc_ordered_extent(
 			struct btrfs_inode *inode,
 			struct fscrypt_extent_info *fscrypt_info,
-			u64 file_offset, u64 num_bytes, u64 ram_bytes,
-			u64 disk_bytenr, u64 disk_num_bytes, u64 offset,
-			unsigned long flags, int compress_type)
+			u64 file_offset, u64 orig_offset, u64 num_bytes,
+			u64 ram_bytes, u64 disk_bytenr, u64 disk_num_bytes,
+			u64 offset, unsigned long flags, int compress_type)
 {
 	struct btrfs_ordered_extent *entry;
 
 	ASSERT((flags & ~BTRFS_ORDERED_TYPE_FLAGS) == 0);
 
 	entry = alloc_ordered_extent(inode, fscrypt_info, file_offset,
-				     num_bytes, ram_bytes, disk_bytenr,
-				     disk_num_bytes, offset, flags,
+				     orig_offset, num_bytes, ram_bytes,
+				     disk_bytenr, disk_num_bytes, offset, flags,
 				     compress_type);
 	if (!IS_ERR(entry))
 		insert_ordered_extent(entry);
@@ -1178,8 +1180,8 @@ struct btrfs_ordered_extent *btrfs_split_ordered_extent(
 		return ERR_PTR(-EINVAL);
 
 	new = alloc_ordered_extent(inode, ordered->fscrypt_info, file_offset,
-				   len, len, disk_bytenr, len, 0, flags,
-				   ordered->compress_type);
+				   ordered->orig_offset, len, len, disk_bytenr,
+				   len, 0, flags, ordered->compress_type);
 	if (IS_ERR(new))
 		return new;
 
@@ -1200,6 +1202,16 @@ struct btrfs_ordered_extent *btrfs_split_ordered_extent(
 	ordered->num_bytes -= len;
 	ordered->disk_num_bytes -= len;
 
+	/*
+	 * ->orig_offset is the original offset of the original extent, which
+	 * for PREALLOC or NOCOW stays the same, but if we're a regular extent
+	 * that means this is a new extent and thus ->orig_offset must equal
+	 * ->file_offset.  This is only important for encryption as we only use
+	 * it for setting the offset for the bio encryption context.
+	 */
+	if (test_bit(BTRFS_ORDERED_REGULAR, &ordered->flags))
+		ordered->orig_offset = ordered->file_offset;
+
 	if (test_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags)) {
 		ASSERT(ordered->bytes_left == 0);
 		new->bytes_left = 0;
diff --git a/fs/btrfs/ordered-data.h b/fs/btrfs/ordered-data.h
index 57ca8ce6eb6d..a8ce181288f7 100644
--- a/fs/btrfs/ordered-data.h
+++ b/fs/btrfs/ordered-data.h
@@ -83,6 +83,12 @@ struct btrfs_ordered_extent {
 	/* logical offset in the file */
 	u64 file_offset;
 
+	/*
+	 * The original logical offset of the extent, this is for NOCOW and
+	 * PREALLOC extents, otherwise it'll be the same as file_offset.
+	 */
+	u64 orig_offset;
+
 	/*
 	 * These fields directly correspond to the same fields in
 	 * btrfs_file_extent_item.
@@ -165,9 +171,9 @@ bool btrfs_dec_test_ordered_pending(struct btrfs_inode *inode,
 struct btrfs_ordered_extent *btrfs_alloc_ordered_extent(
 			struct btrfs_inode *inode,
 			struct fscrypt_extent_info *fscrypt_info,
-			u64 file_offset, u64 num_bytes, u64 ram_bytes,
-			u64 disk_bytenr, u64 disk_num_bytes, u64 offset,
-			unsigned long flags, int compress_type);
+			u64 file_offset, u64 orig_offset, u64 num_bytes,
+			u64 ram_bytes, u64 disk_bytenr, u64 disk_num_bytes,
+			u64 offset, unsigned long flags, int compress_type);
 void btrfs_add_ordered_sum(struct btrfs_ordered_extent *entry,
 			   struct btrfs_ordered_sum *sum);
 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct btrfs_inode *inode,
-- 
2.43.0