btrfs: add dummy callback for readpage_io_failed and drop checks

Make extent_io_ops::readpage_io_failed_hook callback mandatory and
define a dummy function for btrfs_extent_io_ops. As the failed IO
callback is not performance critical, the branch vs extra trade off does
not hurt.

Signed-off-by: David Sterba <dsterba@suse.com>

4 files changed, 10 insertions, 3 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 60d4f1b210d7..cad47ece2fdf 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -4658,7 +4658,7 @@ static const struct extent_io_ops btree_extent_io_ops = {
         .readpage_end_io_hook = btree_readpage_end_io_hook,
         /* note we're sharing with inode.c for the merge bio hook */
         .merge_bio_hook = btrfs_merge_bio_hook,
+        .readpage_io_failed_hook = btree_io_failed_hook,
 
         /* optional callbacks */
-        .readpage_io_failed_hook = btree_io_failed_hook,
 };
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 0786985a8cc5..28e81922a21c 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2581,7 +2581,7 @@ static void end_bio_extent_readpage(struct bio *bio)
                 if (likely(uptodate))
                         goto readpage_ok;
 
-                if (tree->ops && tree->ops->readpage_io_failed_hook) {
+                if (tree->ops) {
                         ret = tree->ops->readpage_io_failed_hook(page, mirror);
                         if (!ret && !bio->bi_error)
                                 uptodate = 1;
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 1f8478dc9f8e..3e4fad4a909d 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -103,6 +103,7 @@ struct extent_io_ops {
         int (*merge_bio_hook)(struct page *page, unsigned long offset,
                               size_t size, struct bio *bio,
                               unsigned long bio_flags);
+        int (*readpage_io_failed_hook)(struct page *page, int failed_mirror);
 
         /*
          * Optional hooks, called if the pointer is not NULL
@@ -110,7 +111,6 @@ struct extent_io_ops {
         int (*fill_delalloc)(struct inode *inode, struct page *locked_page,
                              u64 start, u64 end, int *page_started,
                              unsigned long *nr_written);
-        int (*readpage_io_failed_hook)(struct page *page, int failed_mirror);
 
         int (*writepage_start_hook)(struct page *page, u64 start, u64 end);
         void (*writepage_end_io_hook)(struct page *page, u64 start, u64 end,
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 3b327c8cfb16..ca1995cfd8e9 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -10509,6 +10509,12 @@ out_inode:
 
 }
 
+__attribute__((const))
+static int dummy_readpage_io_failed_hook(struct page *page, int failed_mirror)
+{
+        return 0;
+}
+
 static const struct inode_operations btrfs_dir_inode_operations = {
         .getattr        = btrfs_getattr,
         .lookup         = btrfs_lookup,
@@ -10551,6 +10557,7 @@ static const struct extent_io_ops btrfs_extent_io_ops = {
         .submit_bio_hook = btrfs_submit_bio_hook,
         .readpage_end_io_hook = btrfs_readpage_end_io_hook,
         .merge_bio_hook = btrfs_merge_bio_hook,
+        .readpage_io_failed_hook = dummy_readpage_io_failed_hook,
 
         /* optional callbacks */
         .fill_delalloc = run_delalloc_range,