ext4: create __ext4_insert_dentry for dir entry insertion

The old add_dirent_to_buf handles all the work related to the
work of adding dir entry to a dir block. Now we have inline data,
so create 2 new function __ext4_find_dest_de and __ext4_insert_dentry
that do the real work and let add_dirent_to_buf call them.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

2 files changed, 80 insertions, 40 deletions

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 59cbf498fd5f..8e9e94cf1bca 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1969,6 +1969,21 @@ extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
                                     __u32 minor_hash,
                                     struct ext4_dir_entry_2 *dirent);
 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
+extern int ext4_find_dest_de(struct inode *dir, struct inode *inode,
+                             struct buffer_head *bh,
+                             void *buf, int buf_size,
+                             const char *name, int namelen,
+                             struct ext4_dir_entry_2 **dest_de);
+void ext4_insert_dentry(struct inode *inode,
+                        struct ext4_dir_entry_2 *de,
+                        int buf_size,
+                        const char *name, int namelen);
+static inline void ext4_update_dx_flag(struct inode *inode)
+{
+        if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
+                                     EXT4_FEATURE_COMPAT_DIR_INDEX))
+                ext4_clear_inode_flag(inode, EXT4_INODE_INDEX);
+}
 
 /* fsync.c */
 extern int ext4_sync_file(struct file *, loff_t, loff_t, int);
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 10da2d50a5d8..bb9259d20b55 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1084,13 +1084,6 @@ static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
         dx_set_count(entries, count + 1);
 }
 
-static void ext4_update_dx_flag(struct inode *inode)
-{
-        if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
-                                     EXT4_FEATURE_COMPAT_DIR_INDEX))
-                ext4_clear_inode_flag(inode, EXT4_INODE_INDEX);
-}
-
 /*
  * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
  *
@@ -1614,6 +1607,63 @@ errout:
         return NULL;
 }
 
+int ext4_find_dest_de(struct inode *dir, struct inode *inode,
+                      struct buffer_head *bh,
+                      void *buf, int buf_size,
+                      const char *name, int namelen,
+                      struct ext4_dir_entry_2 **dest_de)
+{
+        struct ext4_dir_entry_2 *de;
+        unsigned short reclen = EXT4_DIR_REC_LEN(namelen);
+        int nlen, rlen;
+        unsigned int offset = 0;
+        char *top;
+
+        de = (struct ext4_dir_entry_2 *)buf;
+        top = buf + buf_size - reclen;
+        while ((char *) de <= top) {
+                if (ext4_check_dir_entry(dir, NULL, de, bh,
+                                         buf, buf_size, offset))
+                        return -EIO;
+                if (ext4_match(namelen, name, de))
+                        return -EEXIST;
+                nlen = EXT4_DIR_REC_LEN(de->name_len);
+                rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
+                if ((de->inode ? rlen - nlen : rlen) >= reclen)
+                        break;
+                de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
+                offset += rlen;
+        }
+        if ((char *) de > top)
+                return -ENOSPC;
+
+        *dest_de = de;
+        return 0;
+}
+
+void ext4_insert_dentry(struct inode *inode,
+                        struct ext4_dir_entry_2 *de,
+                        int buf_size,
+                        const char *name, int namelen)
+{
+
+        int nlen, rlen;
+
+        nlen = EXT4_DIR_REC_LEN(de->name_len);
+        rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
+        if (de->inode) {
+                struct ext4_dir_entry_2 *de1 =
+                                (struct ext4_dir_entry_2 *)((char *)de + nlen);
+                de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
+                de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
+                de = de1;
+        }
+        de->file_type = EXT4_FT_UNKNOWN;
+        de->inode = cpu_to_le32(inode->i_ino);
+        ext4_set_de_type(inode->i_sb, de, inode->i_mode);
+        de->name_len = namelen;
+        memcpy(de->name, name, namelen);
+}
 /*
  * Add a new entry into a directory (leaf) block.  If de is non-NULL,
  * it points to a directory entry which is guaranteed to be large
@@ -1629,12 +1679,10 @@ static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
         struct inode    *dir = dentry->d_parent->d_inode;
         const char      *name = dentry->d_name.name;
         int             namelen = dentry->d_name.len;
-        unsigned int    offset = 0;
         unsigned int    blocksize = dir->i_sb->s_blocksize;
         unsigned short  reclen;
-        int             nlen, rlen, err;
-        char            *top;
         int             csum_size = 0;
+        int             err;
 
         if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
@@ -1642,23 +1690,11 @@ static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
 
         reclen = EXT4_DIR_REC_LEN(namelen);
         if (!de) {
-                de = (struct ext4_dir_entry_2 *)bh->b_data;
-                top = bh->b_data + (blocksize - csum_size) - reclen;
-                while ((char *) de <= top) {
-                        if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data,
-                                                 bh->b_size, offset))
-                                return -EIO;
-                        if (ext4_match(namelen, name, de))
-                                return -EEXIST;
-                        nlen = EXT4_DIR_REC_LEN(de->name_len);
-                        rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
-                        if ((de->inode? rlen - nlen: rlen) >= reclen)
-                                break;
-                        de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
-                        offset += rlen;
-                }
-                if ((char *) de > top)
-                        return -ENOSPC;
+                err = ext4_find_dest_de(dir, inode,
+                                        bh, bh->b_data, blocksize - csum_size,
+                                        name, namelen, &de);
+                if (err)
+                        return err;
         }
         BUFFER_TRACE(bh, "get_write_access");
         err = ext4_journal_get_write_access(handle, bh);
@@ -1668,19 +1704,8 @@ static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
         }
 
         /* By now the buffer is marked for journaling */
-        nlen = EXT4_DIR_REC_LEN(de->name_len);
-        rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
-        if (de->inode) {
-                struct ext4_dir_entry_2 *de1 = (struct ext4_dir_entry_2 *)((char *)de + nlen);
-                de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, blocksize);
-                de->rec_len = ext4_rec_len_to_disk(nlen, blocksize);
-                de = de1;
-        }
-        de->file_type = EXT4_FT_UNKNOWN;
-        de->inode = cpu_to_le32(inode->i_ino);
-        ext4_set_de_type(dir->i_sb, de, inode->i_mode);
-        de->name_len = namelen;
-        memcpy(de->name, name, namelen);
+        ext4_insert_dentry(inode, de, blocksize, name, namelen);
+
         /*
          * XXX shouldn't update any times until successful
          * completion of syscall, but too many callers depend