ext4: migrate cleanup

This patch cleanup code a bit, actual logic not changed
- Move current block pointer to migrate_structure, let's all
  walk info will be in one structure.
- Get rid of usless null ind-block ptr checks, caller already
  does that check.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 35 insertions, 66 deletions

diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c
index 6f07a06f2437..8a9a0912fdae 100644
--- a/fs/ext4/migrate.c
+++ b/fs/ext4/migrate.c
@@ -20,13 +20,13 @@
  * The contiguous blocks details which can be
  * represented by a single extent
  */
-struct list_blocks_struct {
-        ext4_lblk_t first_block, last_block;
+struct migrate_struct {
+        ext4_lblk_t first_block, last_block, curr_block;
         ext4_fsblk_t first_pblock, last_pblock;
 };
 
 static int finish_range(handle_t *handle, struct inode *inode,
-                                struct list_blocks_struct *lb)
+                                struct migrate_struct *lb)
 
 {
         int retval = 0, needed;
@@ -86,8 +86,7 @@ err_out:
 }
 
 static int update_extent_range(handle_t *handle, struct inode *inode,
-                                ext4_fsblk_t pblock, ext4_lblk_t blk_num,
-                                struct list_blocks_struct *lb)
+                               ext4_fsblk_t pblock, struct migrate_struct *lb)
 {
         int retval;
         /*
@@ -95,9 +94,10 @@ static int update_extent_range(handle_t *handle, struct inode *inode,
          */
         if (lb->first_pblock &&
                 (lb->last_pblock+1 == pblock) &&
-                (lb->last_block+1 == blk_num)) {
+                (lb->last_block+1 == lb->curr_block)) {
                 lb->last_pblock = pblock;
-                lb->last_block = blk_num;
+                lb->last_block = lb->curr_block;
+                lb->curr_block++;
                 return 0;
         }
         /*
@@ -105,64 +105,49 @@ static int update_extent_range(handle_t *handle, struct inode *inode,
          */
         retval = finish_range(handle, inode, lb);
         lb->first_pblock = lb->last_pblock = pblock;
-        lb->first_block = lb->last_block = blk_num;
-
+        lb->first_block = lb->last_block = lb->curr_block;
+        lb->curr_block++;
         return retval;
 }
 
 static int update_ind_extent_range(handle_t *handle, struct inode *inode,
-                                   ext4_fsblk_t pblock, ext4_lblk_t *blk_nump,
-                                   struct list_blocks_struct *lb)
+                                   ext4_fsblk_t pblock,
+                                   struct migrate_struct *lb)
 {
         struct buffer_head *bh;
         __le32 *i_data;
         int i, retval = 0;
-        ext4_lblk_t blk_count = *blk_nump;
         unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
 
-        if (!pblock) {
-                /* Only update the file block number */
-                *blk_nump += max_entries;
-                return 0;
-        }
-
         bh = sb_bread(inode->i_sb, pblock);
         if (!bh)
                 return -EIO;
 
         i_data = (__le32 *)bh->b_data;
-        for (i = 0; i < max_entries; i++, blk_count++) {
+        for (i = 0; i < max_entries; i++) {
                 if (i_data[i]) {
                         retval = update_extent_range(handle, inode,
-                                                le32_to_cpu(i_data[i]),
-                                                blk_count, lb);
+                                                le32_to_cpu(i_data[i]), lb);
                         if (retval)
                                 break;
+                } else {
+                        lb->curr_block++;
                 }
         }
-
-        /* Update the file block number */
-        *blk_nump = blk_count;
         put_bh(bh);
         return retval;
 
 }
 
 static int update_dind_extent_range(handle_t *handle, struct inode *inode,
-                                    ext4_fsblk_t pblock, ext4_lblk_t *blk_nump,
-                                    struct list_blocks_struct *lb)
+                                    ext4_fsblk_t pblock,
+                                    struct migrate_struct *lb)
 {
         struct buffer_head *bh;
         __le32 *i_data;
         int i, retval = 0;
-        ext4_lblk_t blk_count = *blk_nump;
         unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
 
-        if (!pblock) {
-                /* Only update the file block number */
-                *blk_nump += max_entries * max_entries;
-                return 0;
-        }
         bh = sb_bread(inode->i_sb, pblock);
         if (!bh)
                 return -EIO;
@@ -171,38 +156,28 @@ static int update_dind_extent_range(handle_t *handle, struct inode *inode,
         for (i = 0; i < max_entries; i++) {
                 if (i_data[i]) {
                         retval = update_ind_extent_range(handle, inode,
-                                                le32_to_cpu(i_data[i]),
-                                                &blk_count, lb);
+                                                le32_to_cpu(i_data[i]), lb);
                         if (retval)
                                 break;
                 } else {
                         /* Only update the file block number */
-                        blk_count += max_entries;
+                        lb->curr_block += max_entries;
                 }
         }
-
-        /* Update the file block number */
-        *blk_nump = blk_count;
         put_bh(bh);
         return retval;
 
 }
 
 static int update_tind_extent_range(handle_t *handle, struct inode *inode,
-                                     ext4_fsblk_t pblock, ext4_lblk_t *blk_nump,
-                                     struct list_blocks_struct *lb)
+                                    ext4_fsblk_t pblock,
+                                    struct migrate_struct *lb)
 {
         struct buffer_head *bh;
         __le32 *i_data;
         int i, retval = 0;
-        ext4_lblk_t blk_count = *blk_nump;
         unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
 
-        if (!pblock) {
-                /* Only update the file block number */
-                *blk_nump += max_entries * max_entries * max_entries;
-                return 0;
-        }
         bh = sb_bread(inode->i_sb, pblock);
         if (!bh)
                 return -EIO;
@@ -211,16 +186,14 @@ static int update_tind_extent_range(handle_t *handle, struct inode *inode,
         for (i = 0; i < max_entries; i++) {
                 if (i_data[i]) {
                         retval = update_dind_extent_range(handle, inode,
-                                                le32_to_cpu(i_data[i]),
-                                                &blk_count, lb);
+                                                le32_to_cpu(i_data[i]), lb);
                         if (retval)
                                 break;
-                } else
+                } else {
                         /* Only update the file block number */
-                        blk_count += max_entries * max_entries;
+                        lb->curr_block += max_entries * max_entries;
+                }
         }
-        /* Update the file block number */
-        *blk_nump = blk_count;
         put_bh(bh);
         return retval;
 
@@ -461,10 +434,9 @@ int ext4_ext_migrate(struct inode *inode)
         handle_t *handle;
         int retval = 0, i;
         __le32 *i_data;
-        ext4_lblk_t blk_count = 0;
         struct ext4_inode_info *ei;
         struct inode *tmp_inode = NULL;
-        struct list_blocks_struct lb;
+        struct migrate_struct lb;
         unsigned long max_entries;
         __u32 goal;
 
@@ -550,35 +522,32 @@ int ext4_ext_migrate(struct inode *inode)
 
         /* 32 bit block address 4 bytes */
         max_entries = inode->i_sb->s_blocksize >> 2;
-        for (i = 0; i < EXT4_NDIR_BLOCKS; i++, blk_count++) {
+        for (i = 0; i < EXT4_NDIR_BLOCKS; i++) {
                 if (i_data[i]) {
                         retval = update_extent_range(handle, tmp_inode,
-                                                le32_to_cpu(i_data[i]),
-                                                blk_count, &lb);
+                                                le32_to_cpu(i_data[i]), &lb);
                         if (retval)
                                 goto err_out;
-                }
+                } else
+                        lb.curr_block++;
         }
         if (i_data[EXT4_IND_BLOCK]) {
                 retval = update_ind_extent_range(handle, tmp_inode,
-                                        le32_to_cpu(i_data[EXT4_IND_BLOCK]),
-                                        &blk_count, &lb);
+                                le32_to_cpu(i_data[EXT4_IND_BLOCK]), &lb);
                         if (retval)
                                 goto err_out;
         } else
-                blk_count +=  max_entries;
+                lb.curr_block += max_entries;
         if (i_data[EXT4_DIND_BLOCK]) {
                 retval = update_dind_extent_range(handle, tmp_inode,
-                                        le32_to_cpu(i_data[EXT4_DIND_BLOCK]),
-                                        &blk_count, &lb);
+                                le32_to_cpu(i_data[EXT4_DIND_BLOCK]), &lb);
                         if (retval)
                                 goto err_out;
         } else
-                blk_count += max_entries * max_entries;
+                lb.curr_block += max_entries * max_entries;
         if (i_data[EXT4_TIND_BLOCK]) {
                 retval = update_tind_extent_range(handle, tmp_inode,
-                                        le32_to_cpu(i_data[EXT4_TIND_BLOCK]),
-                                        &blk_count, &lb);
+                                le32_to_cpu(i_data[EXT4_TIND_BLOCK]), &lb);
                         if (retval)
                                 goto err_out;
         }