btrfs: change btrfs_encoded_read() so that reading of extent is done by caller

btrfs: change btrfs_encoded_read() so that reading of extent is done by caller

[ Upstream commit 26efd44796c6dd7a64f039a0dda6d558eac97a3e ]

Change the behaviour of btrfs_encoded_read() so that if it needs to read
an extent from disk, it leaves the extent and inode locked and returns
-EIOCBQUEUED. The caller is then responsible for doing the I/O via
btrfs_encoded_read_regular() and unlocking the extent and inode.

Signed-off-by: Mark Harmstone <maharmstone@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 05b36b04d74a ("btrfs: fix use-after-free in btrfs_encoded_read_endio()")
Signed-off-by: Sasha Levin <sashal@kernel.org>