On Sun, Sep 29, 2019 at 08:53:05AM +0800, Chao Yu wrote:
> Hi Jaegeuk,
> 
> On 2019/9/28 2:31, Jaegeuk Kim wrote:
> > Hi Chao,
> > 
> > On 09/25, Chao Yu wrote:
> >> evict() should be called once i_count is zero, rather than i_nlinke
> >> is zero.
> >>
> >> Reported-by: Gao Xiang <gaoxian...@huawei.com>
> >> Signed-off-by: Chao Yu <yuch...@huawei.com>
> >> ---
> >>  fs/f2fs/inode.c | 2 +-
> >>  1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
> >> index db4fec30c30d..8262f4a483d3 100644
> >> --- a/fs/f2fs/inode.c
> >> +++ b/fs/f2fs/inode.c
> >> @@ -632,7 +632,7 @@ int f2fs_write_inode(struct inode *inode, struct 
> >> writeback_control *wbc)
> >>  }
> >>  
> >>  /*
> >> - * Called at the last iput() if i_nlink is zero
> > 
> > I don't think this comment is wrong. You may be able to add on top of this.
> 
> It actually misleads the developer or user.
> 
> How do you think of:
> 
> "Called at the last iput() if i_count is zero, and will release all meta/data
> blocks allocated in the inode if i_nlink is zero"

(sigh... side note: I just took some time to check the original meaning
 out of curiosity. AFAIK, the above word was added in Linux-2.1.45 [1]
 due to ext2_delete_inode behavior, which is called when i_nlink == 0,
 and .delete_inode was gone in 2010 (commit 72edc4d0873b merge ext2
 delete_inode and clear_inode, switch to ->evict_inode()), it may be
 helpful to understand the story so I write here for later folks reference.
 And it's also good to just kill it. )

+
+/*
+ * Called at the last iput() if i_nlink is zero.
+ */
+void ext2_delete_inode (struct inode * inode)
+{
+       if (inode->i_ino == EXT2_ACL_IDX_INO ||
            inode->i_ino == EXT2_ACL_DATA_INO)
                return;
        inode->u.ext2_i.i_dtime = CURRENT_TIME;
-       inode->i_dirt = 1;
+       mark_inode_dirty(inode);
        ext2_update_inode(inode, IS_SYNC(inode));
        inode->i_size = 0;
        if (inode->i_blocks)
@@ -248,7 +258,7 @@
        if (IS_SYNC(inode) || inode->u.ext2_i.i_osync)
                ext2_sync_inode (inode);
        else
-               inode->i_dirt = 1;
+               mark_inode_dirty(inode);
        return result;
 }

+void iput(struct inode *inode)
 {
-       struct inode * inode = get_empty_inode();
+       if (inode) {
+               struct super_operations *op = NULL;
 
-       PIPE_BASE(*inode) = (char*)__get_free_page(GFP_USER);
-       if (!(PIPE_BASE(*inode))) {
-               iput(inode);
-               return NULL;
+               if (inode->i_sb && inode->i_sb->s_op)
+                       op = inode->i_sb->s_op;
+               if (op && op->put_inode)
+                       op->put_inode(inode);
+
+               spin_lock(&inode_lock);
+               if (!--inode->i_count) {
+                       if (!inode->i_nlink) {
+                               list_del(&inode->i_hash);
+                               INIT_LIST_HEAD(&inode->i_hash);
+                               if (op && op->delete_inode) {
+                                       void (*delete)(struct inode *) = 
op->delete_inode;
+                                       spin_unlock(&inode_lock);
+                                       delete(inode);
+                                       spin_lock(&inode_lock);
+                               }
+                       }
+                       if (list_empty(&inode->i_hash)) {
+                               list_del(&inode->i_list);
+                               list_add(&inode->i_list, &inode_unused);
+                       }
+               }
+               spin_unlock(&inode_lock);
        }

[1] https://www.kernel.org/pub/linux/kernel/v2.1/patch-2.1.45.xz

Thanks,
Gao Xiang

> 
> Thanks,
> 
> > 
> >> + * Called at the last iput() if i_count is zero
> >>   */
> >>  void f2fs_evict_inode(struct inode *inode)
> >>  {
> >> -- 
> >> 2.18.0.rc1
> > .
> > 
> 
> 
> _______________________________________________
> Linux-f2fs-devel mailing list
> Linux-f2fs-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

Reply via email to