btrfs: tag as unlikely branches that call extent_io_tree_panic()

It's unexpected to ever call extent_io_tree_panic() so surround with
'unlikely' every if statement condition that leads to it, making it
explicit to a reader and to hint the compiler to potentially generate
better code.

On x86_64, using gcc 14.2.0-19 from Debian, this resulted in a slightly
decrease of the btrfs module's text size.

Before:

  $ size fs/btrfs/btrfs.ko
     text	   data	    bss	    dec	    hex	filename
  1999832	 174320	  15592	2189744	 2169b0	fs/btrfs/btrfs.ko

After:

  $ size fs/btrfs/btrfs.ko
     text	   data	    bss	    dec	    hex	filename
  1999768	 174320	  15592	2189680	 216970	fs/btrfs/btrfs.ko

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/extent-io-tree.c b/fs/btrfs/extent-io-tree.c
index 68e48b49395017658905dcdc7e2f83b088ee533c..93dca919924960d3269149fae0822ab8467f0c15 100644 (file)
--- a/fs/btrfs/extent-io-tree.c
+++ b/fs/btrfs/extent-io-tree.c
@@ -696,7 +696,7 @@ hit_next:
                        goto search_again;
                ret = split_state(tree, state, prealloc, start);
                prealloc = NULL;
-               if (ret) {
+               if (unlikely(ret)) {
                        extent_io_tree_panic(tree, state, "split", ret);
                        goto out;
                }
@@ -762,7 +762,7 @@ hit_next:
                if (!prealloc)
                        goto search_again;
                ret = split_state(tree, state, prealloc, end + 1);
-               if (ret) {
+               if (unlikely(ret)) {
                        extent_io_tree_panic(tree, state, "split", ret);
                        prealloc = NULL;
                        goto out;
@@ -1203,7 +1203,7 @@ hit_next:
                if (!prealloc)
                        goto search_again;
                ret = split_state(tree, state, prealloc, start);
-               if (ret)
+               if (unlikely(ret))
                        extent_io_tree_panic(tree, state, "split", ret);
 
                prealloc = NULL;
@@ -1293,7 +1293,7 @@ hit_next:
                if (!prealloc)
                        goto search_again;
                ret = split_state(tree, state, prealloc, end + 1);
-               if (ret) {
+               if (unlikely(ret)) {
                        extent_io_tree_panic(tree, state, "split", ret);
                        prealloc = NULL;
                        goto out;
@@ -1448,7 +1448,7 @@ hit_next:
                }
                ret = split_state(tree, state, prealloc, start);
                prealloc = NULL;
-               if (ret) {
+               if (unlikely(ret)) {
                        extent_io_tree_panic(tree, state, "split", ret);
                        goto out;
                }
@@ -1532,7 +1532,7 @@ hit_next:
                }
 
                ret = split_state(tree, state, prealloc, end + 1);
-               if (ret) {
+               if (unlikely(ret)) {
                        extent_io_tree_panic(tree, state, "split", ret);
                        prealloc = NULL;
                        goto out;