f2fs: reduce unncessary locking pages during read

[GitHub/exynos8895/android_kernel_samsung_universal8895.git] / fs / f2fs / node.c

diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index a3cb1ff34f8ebaabb791853aa57b2f678c80d5f3..9e6ed6708fa8bffbaae80c750d61fd26fe808ef1 100644 (file)
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -100,10 +100,13 @@ static void ra_nat_pages(struct f2fs_sb_info *sbi, int nid)
                page = grab_cache_page(mapping, index);
                if (!page)
                        continue;
-               if (f2fs_readpage(sbi, page, index, READ)) {
+               if (PageUptodate(page)) {
                        f2fs_put_page(page, 1);
                        continue;
                }
+               if (f2fs_readpage(sbi, page, index, READ))
+                       continue;
+
                f2fs_put_page(page, 0);
        }
 }
@@ -851,8 +854,16 @@ static int read_node_page(struct page *page, int type)
 
        get_node_info(sbi, page->index, &ni);
 
-       if (ni.blk_addr == NULL_ADDR)
+       if (ni.blk_addr == NULL_ADDR) {
+               f2fs_put_page(page, 1);
                return -ENOENT;
+       }
+
+       if (PageUptodate(page)) {
+               unlock_page(page);
+               return 0;
+       }
+
        return f2fs_readpage(sbi, page, ni.blk_addr, type);
 }
 
@@ -865,19 +876,18 @@ void ra_node_page(struct f2fs_sb_info *sbi, nid_t nid)
        struct page *apage;
 
        apage = find_get_page(mapping, nid);
-       if (apage && PageUptodate(apage))
-               goto release_out;
+       if (apage && PageUptodate(apage)) {
+               f2fs_put_page(apage, 0);
+               return;
+       }
        f2fs_put_page(apage, 0);
 
        apage = grab_cache_page(mapping, nid);
        if (!apage)
                return;
 
-       if (read_node_page(apage, READA))
-               unlock_page(apage);
-
-release_out:
-       f2fs_put_page(apage, 0);
+       if (read_node_page(apage, READA) == 0)
+               f2fs_put_page(apage, 0);
        return;
 }
 
@@ -892,11 +902,14 @@ struct page *get_node_page(struct f2fs_sb_info *sbi, pgoff_t nid)
                return ERR_PTR(-ENOMEM);
 
        err = read_node_page(page, READ_SYNC);
-       if (err) {
-               f2fs_put_page(page, 1);
+       if (err)
                return ERR_PTR(err);
-       }
 
+       lock_page(page);
+       if (!PageUptodate(page)) {
+               f2fs_put_page(page, 1);
+               return ERR_PTR(-EIO);
+       }
        BUG_ON(nid != nid_of_node(page));
        mark_page_accessed(page);
        return page;
@@ -928,11 +941,8 @@ repeat:
                goto page_hit;
 
        err = read_node_page(page, READ_SYNC);
-       unlock_page(page);
-       if (err) {
-               f2fs_put_page(page, 0);
+       if (err)
                return ERR_PTR(err);
-       }
 
        /* Then, try readahead for siblings of the desired node */
        end = start + MAX_RA_NODE;
@@ -957,6 +967,7 @@ page_hit:
                f2fs_put_page(page, 1);
                goto repeat;
        }
+       mark_page_accessed(page);
        return page;
 }
 
@@ -1473,23 +1484,24 @@ int restore_node_summary(struct f2fs_sb_info *sbi,
        sum_entry = &sum->entries[0];
 
        for (i = 0; i < last_offset; i++, sum_entry++) {
+               /*
+                * In order to read next node page,
+                * we must clear PageUptodate flag.
+                */
+               ClearPageUptodate(page);
+
                if (f2fs_readpage(sbi, page, addr, READ_SYNC))
                        goto out;
 
+               lock_page(page);
                rn = (struct f2fs_node *)page_address(page);
                sum_entry->nid = rn->footer.nid;
                sum_entry->version = 0;
                sum_entry->ofs_in_node = 0;
                addr++;
-
-               /*
-                * In order to read next node page,
-                * we must clear PageUptodate flag.
-                */
-               ClearPageUptodate(page);
        }
-out:
        unlock_page(page);
+out:
        __free_pages(page, 0);
        return 0;
 }