target/linux/generic/pending-4.14/141-jffs2-add-RENAME_EXCHANGE-support.patch

   1 From: Felix Fietkau <nbd@nbd.name>
   2 Subject: jffs2: add RENAME_EXCHANGE support
   3
   4 Signed-off-by: Felix Fietkau <nbd@nbd.name>
   5 ---
   6
   7 --- a/fs/jffs2/dir.c
   8 +++ b/fs/jffs2/dir.c
   9 @@ -777,18 +777,31 @@ static int jffs2_rename (struct inode *o
  10         int ret;
  11         struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dir_i->i_sb);
  12         struct jffs2_inode_info *victim_f = NULL;
  13 +       struct inode *fst_inode = d_inode(old_dentry);
  14 +       struct inode *snd_inode = d_inode(new_dentry);
  15         uint8_t type;
  16         uint32_t now;
  17
  18 -       if (flags & ~(RENAME_NOREPLACE|RENAME_WHITEOUT))
  19 +       if (flags & ~(RENAME_NOREPLACE|RENAME_WHITEOUT|RENAME_EXCHANGE))
  20                 return -EINVAL;
  21
  22 +       if ((flags & RENAME_EXCHANGE) && (old_dir_i != new_dir_i)) {
  23 +               if (S_ISDIR(fst_inode->i_mode) && !S_ISDIR(snd_inode->i_mode)) {
  24 +                       inc_nlink(new_dir_i);
  25 +                       drop_nlink(old_dir_i);
  26 +               }
  27 +               else if (!S_ISDIR(fst_inode->i_mode) && S_ISDIR(snd_inode->i_mode)) {
  28 +                       drop_nlink(new_dir_i);
  29 +                       inc_nlink(old_dir_i);
  30 +               }
  31 +       }
  32 +
  33         /* The VFS will check for us and prevent trying to rename a
  34          * file over a directory and vice versa, but if it's a directory,
  35          * the VFS can't check whether the victim is empty. The filesystem
  36          * needs to do that for itself.
  37          */
  38 -       if (d_really_is_positive(new_dentry)) {
  39 +       if (d_really_is_positive(new_dentry) && !(flags & RENAME_EXCHANGE)) {
  40                 victim_f = JFFS2_INODE_INFO(d_inode(new_dentry));
  41                 if (d_is_dir(new_dentry)) {
  42                         struct jffs2_full_dirent *fd;
  43 @@ -823,7 +836,7 @@ static int jffs2_rename (struct inode *o
  44         if (ret)
  45                 return ret;
  46
  47 -       if (victim_f) {
  48 +       if (victim_f && !(flags & RENAME_EXCHANGE)) {
  49                 /* There was a victim. Kill it off nicely */
  50                 if (d_is_dir(new_dentry))
  51                         clear_nlink(d_inode(new_dentry));
  52 @@ -849,6 +862,12 @@ static int jffs2_rename (struct inode *o
  53         if (flags & RENAME_WHITEOUT)
  54                 /* Replace with whiteout */
  55                 ret = jffs2_whiteout(old_dir_i, old_dentry);
  56 +       else if (flags & RENAME_EXCHANGE)
  57 +               /* Replace the original */
  58 +               ret = jffs2_do_link(c, JFFS2_INODE_INFO(old_dir_i),
  59 +                                   d_inode(new_dentry)->i_ino, type,
  60 +                                   old_dentry->d_name.name, old_dentry->d_name.len,
  61 +                                   now);
  62         else
  63                 /* Unlink the original */
  64                 ret = jffs2_do_unlink(c, JFFS2_INODE_INFO(old_dir_i),
  65 @@ -880,7 +899,7 @@ static int jffs2_rename (struct inode *o
  66                 return ret;
  67         }
  68
  69 -       if (d_is_dir(old_dentry))
  70 +       if (d_is_dir(old_dentry) && !(flags & RENAME_EXCHANGE))
  71                 drop_nlink(old_dir_i);
  72
  73         new_dir_i->i_mtime = new_dir_i->i_ctime = old_dir_i->i_mtime = old_dir_i->i_ctime = ITIME(now);