[PATCH] btrfs: send, remove stale code when checking for shared extents

[PATCH] btrfs: send, remove stale code when checking for shared extents

[fdmanana]

From: Filipe Manana <fdmanana@suse.com>

After commit 040ee6120cb670 ("Btrfs: send, improve clone range") we do not
use anymore the data_offset field of struct backref_ctx, as after that we
do all the necessary checks for the data offset of file extent items at
clone_range(). Since there are no more users of data_offset from that
structure, remove it.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
---
 fs/btrfs/send.c | 16 ----------------
 1 file changed, 16 deletions(-)

diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index 1eaa004d97cd..9dd59611838c 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -1191,9 +1191,6 @@ struct backref_ctx {
 	/* may be truncated in case it's the last extent in a file */
 	u64 extent_len;
 
-	/* data offset in the file extent item */
-	u64 data_offset;
-
 	/* Just to check for bugs in backref resolving */
 	int found_itself;
 };
@@ -1401,19 +1398,6 @@ static int find_extent_clone(struct send_ctx *sctx,
 	backref_ctx->cur_offset = data_offset;
 	backref_ctx->found_itself = 0;
 	backref_ctx->extent_len = num_bytes;
-	/*
-	 * For non-compressed extents iterate_extent_inodes() gives us extent
-	 * offsets that already take into account the data offset, but not for
-	 * compressed extents, since the offset is logical and not relative to
-	 * the physical extent locations. We must take this into account to
-	 * avoid sending clone offsets that go beyond the source file's size,
-	 * which would result in the clone ioctl failing with -EINVAL on the
-	 * receiving end.
-	 */
-	if (compressed == BTRFS_COMPRESS_NONE)
-		backref_ctx->data_offset = 0;
-	else
-		backref_ctx->data_offset = btrfs_file_extent_offset(eb, fi);
 
 	/*
 	 * The last extent of a file may be too large due to page alignment.
-- 
2.28.0

Re: [PATCH] btrfs: send, remove stale code when checking for shared extents

[David Sterba]

On Mon, Jan 11, 2021 at 11:42:32AM +0000, fdmanana@kernel.org wrote:
> From: Filipe Manana <fdmanana@suse.com>
> 
> After commit 040ee6120cb670 ("Btrfs: send, improve clone range") we do not
> use anymore the data_offset field of struct backref_ctx, as after that we
> do all the necessary checks for the data offset of file extent items at
> clone_range(). Since there are no more users of data_offset from that
> structure, remove it.
> 
> Signed-off-by: Filipe Manana <fdmanana@suse.com>

Added to misc-next, thanks.