convert-ext4_dx_find_entry-to-use-the-ERR_PTR-convention

   1 ext4: convert ext4_dx_find_entry() to use the ERR_PTR convention
   2
   3 From: Theodore Ts'o <tytso@mit.edu>
   4
   5 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
   6 ---
   7  fs/ext4/namei.c | 46 ++++++++++++++++++++--------------------------
   8  1 file changed, 20 insertions(+), 26 deletions(-)
   9
  10 diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
  11 index 90a3cdc..1421ec1 100644
  12 --- a/fs/ext4/namei.c
  13 +++ b/fs/ext4/namei.c
  14 @@ -270,8 +270,7 @@ static int ext4_htree_next_block(struct inode *dir, __u32 hash,
  15                                  __u32 *start_hash);
  16  static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
  17                 const struct qstr *d_name,
  18 -               struct ext4_dir_entry_2 **res_dir,
  19 -               int *err);
  20 +               struct ext4_dir_entry_2 **res_dir);
  21  static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
  22                              struct inode *inode);
  23
  24 @@ -1258,17 +1257,13 @@ static struct buffer_head * ext4_find_entry (struct inode *dir,
  25                 goto restart;
  26         }
  27         if (is_dx(dir)) {
  28 -               bh = ext4_dx_find_entry(dir, d_name, res_dir, &err);
  29 +               bh = ext4_dx_find_entry(dir, d_name, res_dir);
  30                 /*
  31                  * On success, or if the error was file not found,
  32                  * return.  Otherwise, fall back to doing a search the
  33                  * old fashioned way.
  34                  */
  35 -               if (err == -ENOENT)
  36 -                       return NULL;
  37 -               if (err && err != ERR_BAD_DX_DIR)
  38 -                       return ERR_PTR(err);
  39 -               if (bh)
  40 +               if (!IS_ERR(bh) || PTR_ERR(bh) != ERR_BAD_DX_DIR)
  41                         return bh;
  42                 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
  43                                "falling back\n"));
  44 @@ -1366,34 +1361,32 @@ cleanup_and_exit:
  45  }
  46
  47  static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name,
  48 -                      struct ext4_dir_entry_2 **res_dir, int *err)
  49 +                      struct ext4_dir_entry_2 **res_dir)
  50  {
  51         struct super_block * sb = dir->i_sb;
  52         struct dx_hash_info     hinfo;
  53         struct dx_frame frames[2], *frame;
  54         struct buffer_head *bh;
  55         ext4_lblk_t block;
  56 -       int retval;
  57 +       int err = 0, retval;
  58
  59 -       if (!(frame = dx_probe(d_name, dir, &hinfo, frames, err)))
  60 -               return NULL;
  61 +       frame = dx_probe(d_name, dir, &hinfo, frames, &err);
  62 +       if (err)
  63 +               return ERR_PTR(err);
  64         do {
  65                 block = dx_get_block(frame->at);
  66                 bh = ext4_read_dirblock(dir, block, DIRENT);
  67 -               if (IS_ERR(bh)) {
  68 -                       *err = PTR_ERR(bh);
  69 +               if (IS_ERR(bh))
  70                         goto errout;
  71 -               }
  72 +
  73                 retval = search_dirblock(bh, dir, d_name,
  74                                          block << EXT4_BLOCK_SIZE_BITS(sb),
  75                                          res_dir);
  76 -               if (retval == 1) {      /* Success! */
  77 -                       dx_release(frames);
  78 -                       return bh;
  79 -               }
  80 +               if (retval == 1)
  81 +                       goto success;
  82                 brelse(bh);
  83                 if (retval == -1) {
  84 -                       *err = ERR_BAD_DX_DIR;
  85 +                       bh = ERR_PTR(ERR_BAD_DX_DIR);
  86                         goto errout;
  87                 }
  88
  89 @@ -1402,18 +1395,19 @@ static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct q
  90                                                frames, NULL);
  91                 if (retval < 0) {
  92                         ext4_warning(sb,
  93 -                            "error reading index page in directory #%lu",
  94 -                            dir->i_ino);
  95 -                       *err = retval;
  96 +                            "error %d reading index page in directory #%lu",
  97 +                            retval, dir->i_ino);
  98 +                       bh = ERR_PTR(retval);
  99                         goto errout;
 100                 }
 101         } while (retval == 1);
 102
 103 -       *err = -ENOENT;
 104 +       bh = NULL;
 105  errout:
 106         dxtrace(printk(KERN_DEBUG "%s not found\n", d_name->name));
 107 -       dx_release (frames);
 108 -       return NULL;
 109 +success:
 110 +       dx_release(frames);
 111 +       return bh;
 112  }
 113
 114  static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
 115 --
 116 2.1.0
 117