f2fs: add unlikely() macro for compiler more aggressively

This patch adds unlikely() macro into the most of codes.
The basic rule is to add that when:
- checking unusual errors,
- checking page mappings,
- and the other unlikely conditions.

Change log from v1:
 - Don't add unlikely for the NULL test and error test: advised by Andi Kleen.

Cc: Chao Yu <chao2.yu@samsung.com>
Cc: Andi Kleen <andi@firstfloor.org>
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

1 files changed, 14 insertions, 14 deletions

diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 2e41636be476..6c6ef772cf01 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -750,7 +750,7 @@ skip_partial:
                 if (offset[1] == 0 &&
                                 rn->i.i_nid[offset[0] - NODE_DIR1_BLOCK]) {
                         lock_page(page);
-                        if (page->mapping != node_mapping) {
+                        if (unlikely(page->mapping != node_mapping)) {
                                 f2fs_put_page(page, 1);
                                 goto restart;
                         }
@@ -841,14 +841,14 @@ struct page *new_node_page(struct dnode_of_data *dn,
         struct page *page;
         int err;
 
-        if (is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC))
+        if (unlikely(is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC)))
                 return ERR_PTR(-EPERM);
 
         page = grab_cache_page(mapping, dn->nid);
         if (!page)
                 return ERR_PTR(-ENOMEM);
 
-        if (!inc_valid_node_count(sbi, dn->inode)) {
+        if (unlikely(!inc_valid_node_count(sbi, dn->inode))) {
                 err = -ENOSPC;
                 goto fail;
         }
@@ -898,7 +898,7 @@ static int read_node_page(struct page *page, int rw)
 
         get_node_info(sbi, page->index, &ni);
 
-        if (ni.blk_addr == NULL_ADDR) {
+        if (unlikely(ni.blk_addr == NULL_ADDR)) {
                 f2fs_put_page(page, 1);
                 return -ENOENT;
         }
@@ -953,11 +953,11 @@ repeat:
                 goto got_it;
 
         lock_page(page);
-        if (!PageUptodate(page)) {
+        if (unlikely(!PageUptodate(page))) {
                 f2fs_put_page(page, 1);
                 return ERR_PTR(-EIO);
         }
-        if (page->mapping != mapping) {
+        if (unlikely(page->mapping != mapping)) {
                 f2fs_put_page(page, 1);
                 goto repeat;
         }
@@ -1010,12 +1010,12 @@ repeat:
         blk_finish_plug(&plug);
 
         lock_page(page);
-        if (page->mapping != mapping) {
+        if (unlikely(page->mapping != mapping)) {
                 f2fs_put_page(page, 1);
                 goto repeat;
         }
 page_hit:
-        if (!PageUptodate(page)) {
+        if (unlikely(!PageUptodate(page))) {
                 f2fs_put_page(page, 1);
                 return ERR_PTR(-EIO);
         }
@@ -1173,9 +1173,9 @@ int wait_on_node_pages_writeback(struct f2fs_sb_info *sbi, nid_t ino)
                 cond_resched();
         }
 
-        if (test_and_clear_bit(AS_ENOSPC, &mapping->flags))
+        if (unlikely(test_and_clear_bit(AS_ENOSPC, &mapping->flags)))
                 ret2 = -ENOSPC;
-        if (test_and_clear_bit(AS_EIO, &mapping->flags))
+        if (unlikely(test_and_clear_bit(AS_EIO, &mapping->flags)))
                 ret2 = -EIO;
         if (!ret)
                 ret = ret2;
@@ -1202,7 +1202,7 @@ static int f2fs_write_node_page(struct page *page,
         get_node_info(sbi, nid, &ni);
 
         /* This page is already truncated */
-        if (ni.blk_addr == NULL_ADDR) {
+        if (unlikely(ni.blk_addr == NULL_ADDR)) {
                 dec_page_count(sbi, F2FS_DIRTY_NODES);
                 unlock_page(page);
                 return 0;
@@ -1627,14 +1627,14 @@ int restore_node_summary(struct f2fs_sb_info *sbi,
                 list_for_each_entry_safe(page, tmp, &page_list, lru) {
 
                         lock_page(page);
-                        if(PageUptodate(page)) {
+                        if (unlikely(!PageUptodate(page))) {
+                                err = -EIO;
+                        } else {
                                 rn = F2FS_NODE(page);
                                 sum_entry->nid = rn->footer.nid;
                                 sum_entry->version = 0;
                                 sum_entry->ofs_in_node = 0;
                                 sum_entry++;
-                        } else {
-                                err = -EIO;
                         }
 
                         list_del(&page->lru);