target/linux/generic/patches-4.4/111-jffs2-add-RENAME_EXCHANGE-support.patch

   1 From: Felix Fietkau <nbd@nbd.name>
   2 Date: Sat, 25 Apr 2015 12:41:32 +0200
   3 Subject: [PATCH] jffs2: add RENAME_EXCHANGE support
   4
   5 Signed-off-by: Felix Fietkau <nbd@nbd.name>
   6 ---
   7
   8 --- a/fs/jffs2/dir.c
   9 +++ b/fs/jffs2/dir.c
  10 @@ -779,18 +779,31 @@ static int jffs2_rename (struct inode *o
  11         int ret;
  12         struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dir_i->i_sb);
  13         struct jffs2_inode_info *victim_f = NULL;
  14 +       struct inode *fst_inode = d_inode(old_dentry);
  15 +       struct inode *snd_inode = d_inode(new_dentry);
  16         uint8_t type;
  17         uint32_t now;
  18
  19 -       if (flags & ~RENAME_WHITEOUT)
  20 +       if (flags & ~(RENAME_WHITEOUT | RENAME_EXCHANGE))
  21                 return -EINVAL;
  22
  23 +       if ((flags & RENAME_EXCHANGE) && (old_dir_i != new_dir_i)) {
  24 +               if (S_ISDIR(fst_inode->i_mode) && !S_ISDIR(snd_inode->i_mode)) {
  25 +                       inc_nlink(new_dir_i);
  26 +                       drop_nlink(old_dir_i);
  27 +               }
  28 +               else if (!S_ISDIR(fst_inode->i_mode) && S_ISDIR(snd_inode->i_mode)) {
  29 +                       drop_nlink(new_dir_i);
  30 +                       inc_nlink(old_dir_i);
  31 +               }
  32 +       }
  33 +
  34         /* The VFS will check for us and prevent trying to rename a
  35          * file over a directory and vice versa, but if it's a directory,
  36          * the VFS can't check whether the victim is empty. The filesystem
  37          * needs to do that for itself.
  38          */
  39 -       if (d_really_is_positive(new_dentry)) {
  40 +       if (d_really_is_positive(new_dentry) && !(flags & RENAME_EXCHANGE)) {
  41                 victim_f = JFFS2_INODE_INFO(d_inode(new_dentry));
  42                 if (d_is_dir(new_dentry)) {
  43                         struct jffs2_full_dirent *fd;
  44 @@ -825,7 +838,7 @@ static int jffs2_rename (struct inode *o
  45         if (ret)
  46                 return ret;
  47
  48 -       if (victim_f) {
  49 +       if (victim_f && !(flags & RENAME_EXCHANGE)) {
  50                 /* There was a victim. Kill it off nicely */
  51                 if (d_is_dir(new_dentry))
  52                         clear_nlink(d_inode(new_dentry));
  53 @@ -845,12 +858,18 @@ static int jffs2_rename (struct inode *o
  54
  55         /* If it was a directory we moved, and there was no victim,
  56            increase i_nlink on its new parent */
  57 -       if (d_is_dir(old_dentry) && !victim_f)
  58 +       if (d_is_dir(old_dentry) && !victim_f && !(flags & RENAME_EXCHANGE))
  59                 inc_nlink(new_dir_i);
  60
  61         if (flags & RENAME_WHITEOUT)
  62                 /* Replace with whiteout */
  63                 ret = jffs2_whiteout(old_dir_i, old_dentry);
  64 +       else if (flags & RENAME_EXCHANGE)
  65 +               /* Replace the original */
  66 +               ret = jffs2_do_link(c, JFFS2_INODE_INFO(old_dir_i),
  67 +                                   d_inode(new_dentry)->i_ino, type,
  68 +                                   old_dentry->d_name.name, old_dentry->d_name.len,
  69 +                                   now);
  70         else
  71                 /* Unlink the original */
  72                 ret = jffs2_do_unlink(c, JFFS2_INODE_INFO(old_dir_i),
  73 @@ -882,7 +901,7 @@ static int jffs2_rename (struct inode *o
  74                 return ret;
  75         }
  76
  77 -       if (d_is_dir(old_dentry))
  78 +       if (d_is_dir(old_dentry) && !(flags & RENAME_EXCHANGE))
  79                 drop_nlink(old_dir_i);
  80
  81         new_dir_i->i_mtime = new_dir_i->i_ctime = old_dir_i->i_mtime = old_dir_i->i_ctime = ITIME(now);