Merge tag 'for-f2fs-4.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs

Pull f2fs fixes from Jaegeuk Kim:
 "Fix a performance regression and a bug"

* tag 'for-f2fs-4.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs:
  f2fs: fix wrong error hanlder in f2fs_follow_link
  Revert "f2fs: enhance multi-threads performance"

4 files changed, 12 insertions, 5 deletions

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index b91b0e10678e..1e1aae669fa8 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1513,6 +1513,7 @@ static int f2fs_write_data_pages(struct address_space *mapping,
 {
         struct inode *inode = mapping->host;
         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+        bool locked = false;
         int ret;
         long diff;
 
@@ -1533,7 +1534,13 @@ static int f2fs_write_data_pages(struct address_space *mapping,
 
         diff = nr_pages_to_write(sbi, DATA, wbc);
 
+        if (!S_ISDIR(inode->i_mode)) {
+                mutex_lock(&sbi->writepages);
+                locked = true;
+        }
         ret = write_cache_pages(mapping, wbc, __f2fs_writepage, mapping);
+        if (locked)
+                mutex_unlock(&sbi->writepages);
 
         f2fs_submit_merged_bio(sbi, DATA, WRITE);
 
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index d8921cf2ba9a..8de34ab6d5b1 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -625,6 +625,7 @@ struct f2fs_sb_info {
         struct mutex cp_mutex;                  /* checkpoint procedure lock */
         struct rw_semaphore cp_rwsem;           /* blocking FS operations */
         struct rw_semaphore node_write;         /* locking node writes */
+        struct mutex writepages;                /* mutex for writepages() */
         wait_queue_head_t cp_wait;
 
         struct inode_management im[MAX_INO_ENTRY];      /* manage inode cache */
diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index 7e3794edae42..658e8079aaf9 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -298,16 +298,14 @@ fail:
 
 static void *f2fs_follow_link(struct dentry *dentry, struct nameidata *nd)
 {
-        struct page *page;
+        struct page *page = page_follow_link_light(dentry, nd);
 
-        page = page_follow_link_light(dentry, nd);
-        if (IS_ERR(page))
+        if (IS_ERR_OR_NULL(page))
                 return page;
 
         /* this is broken symlink case */
         if (*nd_get_link(nd) == 0) {
-                kunmap(page);
-                page_cache_release(page);
+                page_put_link(dentry, nd, page);
                 return ERR_PTR(-ENOENT);
         }
         return page;
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 160b88346b24..b2dd1b01f076 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1035,6 +1035,7 @@ try_onemore:
         sbi->raw_super = raw_super;
         sbi->raw_super_buf = raw_super_buf;
         mutex_init(&sbi->gc_mutex);
+        mutex_init(&sbi->writepages);
         mutex_init(&sbi->cp_mutex);
         init_rwsem(&sbi->node_write);
         clear_sbi_flag(sbi, SBI_POR_DOING);