1 files changed, 224 insertions, 110 deletions

diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c
index bbf2dd9404dc..c07a2915e40b 100644
--- a/fs/ext4/move_extent.c
+++ b/fs/ext4/move_extent.c
@@ -19,14 +19,31 @@
 #include "ext4_extents.h"
 #include "ext4.h"
 
-#define get_ext_path(path, inode, block, ret)           \
-        do {                                                            \
-                path = ext4_ext_find_extent(inode, block, path);        \
-                if (IS_ERR(path)) {                                     \
-                        ret = PTR_ERR(path);                            \
-                        path = NULL;                                    \
-                }                                                       \
-        } while (0)
+/**
+ * get_ext_path - Find an extent path for designated logical block number.
+ *
+ * @inode:      an inode which is searched
+ * @lblock:     logical block number to find an extent path
+ * @path:       pointer to an extent path pointer (for output)
+ *
+ * ext4_ext_find_extent wrapper. Return 0 on success, or a negative error value
+ * on failure.
+ */
+static inline int
+get_ext_path(struct inode *inode, ext4_lblk_t lblock,
+                struct ext4_ext_path **path)
+{
+        int ret = 0;
+
+        *path = ext4_ext_find_extent(inode, lblock, *path);
+        if (IS_ERR(*path)) {
+                ret = PTR_ERR(*path);
+                *path = NULL;
+        } else if ((*path)[ext_depth(inode)].p_ext == NULL)
+                ret = -ENODATA;
+
+        return ret;
+}
 
 /**
  * copy_extent_status - Copy the extent's initialization status
@@ -113,6 +130,31 @@ mext_next_extent(struct inode *inode, struct ext4_ext_path *path,
 }
 
 /**
+ * mext_check_null_inode - NULL check for two inodes
+ *
+ * If inode1 or inode2 is NULL, return -EIO. Otherwise, return 0.
+ */
+static int
+mext_check_null_inode(struct inode *inode1, struct inode *inode2,
+                const char *function)
+{
+        int ret = 0;
+
+        if (inode1 == NULL) {
+                ext4_error(inode2->i_sb, function,
+                        "Both inodes should not be NULL: "
+                        "inode1 NULL inode2 %lu", inode2->i_ino);
+                ret = -EIO;
+        } else if (inode2 == NULL) {
+                ext4_error(inode1->i_sb, function,
+                        "Both inodes should not be NULL: "
+                        "inode1 %lu inode2 NULL", inode1->i_ino);
+                ret = -EIO;
+        }
+        return ret;
+}
+
+/**
  * mext_double_down_read - Acquire two inodes' read semaphore
  *
  * @orig_inode:         original inode structure
@@ -124,8 +166,6 @@ mext_double_down_read(struct inode *orig_inode, struct inode *donor_inode)
 {
         struct inode *first = orig_inode, *second = donor_inode;
 
-        BUG_ON(orig_inode == NULL || donor_inode == NULL);
-
         /*
          * Use the inode number to provide the stable locking order instead
          * of its address, because the C language doesn't guarantee you can
@@ -152,8 +192,6 @@ mext_double_down_write(struct inode *orig_inode, struct inode *donor_inode)
 {
         struct inode *first = orig_inode, *second = donor_inode;
 
-        BUG_ON(orig_inode == NULL || donor_inode == NULL);
-
         /*
          * Use the inode number to provide the stable locking order instead
          * of its address, because the C language doesn't guarantee you can
@@ -178,8 +216,6 @@ mext_double_down_write(struct inode *orig_inode, struct inode *donor_inode)
 static void
 mext_double_up_read(struct inode *orig_inode, struct inode *donor_inode)
 {
-        BUG_ON(orig_inode == NULL || donor_inode == NULL);
-
         up_read(&EXT4_I(orig_inode)->i_data_sem);
         up_read(&EXT4_I(donor_inode)->i_data_sem);
 }
@@ -194,8 +230,6 @@ mext_double_up_read(struct inode *orig_inode, struct inode *donor_inode)
 static void
 mext_double_up_write(struct inode *orig_inode, struct inode *donor_inode)
 {
-        BUG_ON(orig_inode == NULL || donor_inode == NULL);
-
         up_write(&EXT4_I(orig_inode)->i_data_sem);
         up_write(&EXT4_I(donor_inode)->i_data_sem);
 }
@@ -283,8 +317,8 @@ mext_insert_across_blocks(handle_t *handle, struct inode *orig_inode,
         }
 
         if (new_flag) {
-                get_ext_path(orig_path, orig_inode, eblock, err);
-                if (orig_path == NULL)
+                err = get_ext_path(orig_inode, eblock, &orig_path);
+                if (err)
                         goto out;
 
                 if (ext4_ext_insert_extent(handle, orig_inode,
@@ -293,9 +327,9 @@ mext_insert_across_blocks(handle_t *handle, struct inode *orig_inode,
         }
 
         if (end_flag) {
-                get_ext_path(orig_path, orig_inode,
-                                      le32_to_cpu(end_ext->ee_block) - 1, err);
-                if (orig_path == NULL)
+                err = get_ext_path(orig_inode,
+                                le32_to_cpu(end_ext->ee_block) - 1, &orig_path);
+                if (err)
                         goto out;
 
                 if (ext4_ext_insert_extent(handle, orig_inode,
@@ -519,7 +553,15 @@ mext_leaf_block(handle_t *handle, struct inode *orig_inode,
          * oext      |-----------|
          * new_ext       |-------|
          */
-        BUG_ON(le32_to_cpu(oext->ee_block) + oext_alen - 1 < new_ext_end);
+        if (le32_to_cpu(oext->ee_block) + oext_alen - 1 < new_ext_end) {
+                ext4_error(orig_inode->i_sb, __func__,
+                        "new_ext_end(%u) should be less than or equal to "
+                        "oext->ee_block(%u) + oext_alen(%d) - 1",
+                        new_ext_end, le32_to_cpu(oext->ee_block),
+                        oext_alen);
+                ret = -EIO;
+                goto out;
+        }
 
         /*
          * Case: new_ext is smaller than original extent
@@ -543,6 +585,7 @@ mext_leaf_block(handle_t *handle, struct inode *orig_inode,
 
         ret = mext_insert_extents(handle, orig_inode, orig_path, o_start,
                                 o_end, &start_ext, &new_ext, &end_ext);
+out:
         return ret;
 }
 
@@ -554,8 +597,10 @@ mext_leaf_block(handle_t *handle, struct inode *orig_inode,
  * @orig_off:           block offset of original inode
  * @donor_off:          block offset of donor inode
  * @max_count:          the maximun length of extents
+ *
+ * Return 0 on success, or a negative error value on failure.
  */
-static void
+static int
 mext_calc_swap_extents(struct ext4_extent *tmp_dext,
                               struct ext4_extent *tmp_oext,
                               ext4_lblk_t orig_off, ext4_lblk_t donor_off,
@@ -564,6 +609,19 @@ mext_calc_swap_extents(struct ext4_extent *tmp_dext,
         ext4_lblk_t diff, orig_diff;
         struct ext4_extent dext_old, oext_old;
 
+        BUG_ON(orig_off != donor_off);
+
+        /* original and donor extents have to cover the same block offset */
+        if (orig_off < le32_to_cpu(tmp_oext->ee_block) ||
+            le32_to_cpu(tmp_oext->ee_block) +
+                        ext4_ext_get_actual_len(tmp_oext) - 1 < orig_off)
+                return -ENODATA;
+
+        if (orig_off < le32_to_cpu(tmp_dext->ee_block) ||
+            le32_to_cpu(tmp_dext->ee_block) +
+                        ext4_ext_get_actual_len(tmp_dext) - 1 < orig_off)
+                return -ENODATA;
+
         dext_old = *tmp_dext;
         oext_old = *tmp_oext;
 
@@ -591,6 +649,8 @@ mext_calc_swap_extents(struct ext4_extent *tmp_dext,
 
         copy_extent_status(&oext_old, tmp_dext);
         copy_extent_status(&dext_old, tmp_oext);
+
+        return 0;
 }
 
 /**
@@ -631,13 +691,13 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode,
         mext_double_down_write(orig_inode, donor_inode);
 
         /* Get the original extent for the block "orig_off" */
-        get_ext_path(orig_path, orig_inode, orig_off, err);
-        if (orig_path == NULL)
+        err = get_ext_path(orig_inode, orig_off, &orig_path);
+        if (err)
                 goto out;
 
         /* Get the donor extent for the head */
-        get_ext_path(donor_path, donor_inode, donor_off, err);
-        if (donor_path == NULL)
+        err = get_ext_path(donor_inode, donor_off, &donor_path);
+        if (err)
                 goto out;
         depth = ext_depth(orig_inode);
         oext = orig_path[depth].p_ext;
@@ -647,13 +707,28 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode,
         dext = donor_path[depth].p_ext;
         tmp_dext = *dext;
 
-        mext_calc_swap_extents(&tmp_dext, &tmp_oext, orig_off,
+        err = mext_calc_swap_extents(&tmp_dext, &tmp_oext, orig_off,
                                       donor_off, count);
+        if (err)
+                goto out;
 
         /* Loop for the donor extents */
         while (1) {
                 /* The extent for donor must be found. */
-                BUG_ON(!dext || donor_off != le32_to_cpu(tmp_dext.ee_block));
+                if (!dext) {
+                        ext4_error(donor_inode->i_sb, __func__,
+                                   "The extent for donor must be found");
+                        err = -EIO;
+                        goto out;
+                } else if (donor_off != le32_to_cpu(tmp_dext.ee_block)) {
+                        ext4_error(donor_inode->i_sb, __func__,
+                                "Donor offset(%u) and the first block of donor "
+                                "extent(%u) should be equal",
+                                donor_off,
+                                le32_to_cpu(tmp_dext.ee_block));
+                        err = -EIO;
+                        goto out;
+                }
 
                 /* Set donor extent to orig extent */
                 err = mext_leaf_block(handle, orig_inode,
@@ -678,8 +753,8 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode,
 
                 if (orig_path)
                         ext4_ext_drop_refs(orig_path);
-                get_ext_path(orig_path, orig_inode, orig_off, err);
-                if (orig_path == NULL)
+                err = get_ext_path(orig_inode, orig_off, &orig_path);
+                if (err)
                         goto out;
                 depth = ext_depth(orig_inode);
                 oext = orig_path[depth].p_ext;
@@ -692,9 +767,8 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode,
 
                 if (donor_path)
                         ext4_ext_drop_refs(donor_path);
-                get_ext_path(donor_path, donor_inode,
-                                      donor_off, err);
-                if (donor_path == NULL)
+                err = get_ext_path(donor_inode, donor_off, &donor_path);
+                if (err)
                         goto out;
                 depth = ext_depth(donor_inode);
                 dext = donor_path[depth].p_ext;
@@ -705,9 +779,10 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode,
                 }
                 tmp_dext = *dext;
 
-                mext_calc_swap_extents(&tmp_dext, &tmp_oext, orig_off,
-                                              donor_off,
-                                              count - replaced_count);
+                err = mext_calc_swap_extents(&tmp_dext, &tmp_oext, orig_off,
+                                           donor_off, count - replaced_count);
+                if (err)
+                        goto out;
         }
 
 out:
@@ -740,7 +815,7 @@ out:
  * on success, or a negative error value on failure.
  */
 static int
-move_extent_par_page(struct file *o_filp, struct inode *donor_inode,
+move_extent_per_page(struct file *o_filp, struct inode *donor_inode,
                   pgoff_t orig_page_offset, int data_offset_in_page,
                   int block_len_in_page, int uninit)
 {
@@ -871,6 +946,7 @@ out:
                 if (PageLocked(page))
                         unlock_page(page);
                 page_cache_release(page);
+                ext4_journal_stop(handle);
         }
 out2:
         ext4_journal_stop(handle);
@@ -897,6 +973,10 @@ mext_check_arguments(struct inode *orig_inode,
                           struct inode *donor_inode, __u64 orig_start,
                           __u64 donor_start, __u64 *len, __u64 moved_len)
 {
+        ext4_lblk_t orig_blocks, donor_blocks;
+        unsigned int blkbits = orig_inode->i_blkbits;
+        unsigned int blocksize = 1 << blkbits;
+
         /* Regular file check */
         if (!S_ISREG(orig_inode->i_mode) || !S_ISREG(donor_inode->i_mode)) {
                 ext4_debug("ext4 move extent: The argument files should be "
@@ -960,54 +1040,58 @@ mext_check_arguments(struct inode *orig_inode,
                 return -EINVAL;
         }
 
-        if ((orig_start > MAX_DEFRAG_SIZE) ||
-            (donor_start > MAX_DEFRAG_SIZE) ||
-            (*len > MAX_DEFRAG_SIZE) ||
-            (orig_start + *len > MAX_DEFRAG_SIZE))  {
-                ext4_debug("ext4 move extent: Can't handle over [%lu] blocks "
-                        "[ino:orig %lu, donor %lu]\n", MAX_DEFRAG_SIZE,
+        if ((orig_start > EXT_MAX_BLOCK) ||
+            (donor_start > EXT_MAX_BLOCK) ||
+            (*len > EXT_MAX_BLOCK) ||
+            (orig_start + *len > EXT_MAX_BLOCK))  {
+                ext4_debug("ext4 move extent: Can't handle over [%u] blocks "
+                        "[ino:orig %lu, donor %lu]\n", EXT_MAX_BLOCK,
                         orig_inode->i_ino, donor_inode->i_ino);
                 return -EINVAL;
         }
 
         if (orig_inode->i_size > donor_inode->i_size) {
-                if (orig_start >= donor_inode->i_size) {
+                donor_blocks = (donor_inode->i_size + blocksize - 1) >> blkbits;
+                /* TODO: eliminate this artificial restriction */
+                if (orig_start >= donor_blocks) {
                         ext4_debug("ext4 move extent: orig start offset "
-                        "[%llu] should be less than donor file size "
-                        "[%lld] [ino:orig %lu, donor_inode %lu]\n",
-                        orig_start, donor_inode->i_size,
+                        "[%llu] should be less than donor file blocks "
+                        "[%u] [ino:orig %lu, donor %lu]\n",
+                        orig_start, donor_blocks,
                         orig_inode->i_ino, donor_inode->i_ino);
                         return -EINVAL;
                 }
 
-                if (orig_start + *len > donor_inode->i_size) {
+                /* TODO: eliminate this artificial restriction */
+                if (orig_start + *len > donor_blocks) {
                         ext4_debug("ext4 move extent: End offset [%llu] should "
-                                "be less than donor file size [%lld]."
-                                "So adjust length from %llu to %lld "
+                                "be less than donor file blocks [%u]."
+                                "So adjust length from %llu to %llu "
                                 "[ino:orig %lu, donor %lu]\n",
-                                orig_start + *len, donor_inode->i_size,
-                                *len, donor_inode->i_size - orig_start,
+                                orig_start + *len, donor_blocks,
+                                *len, donor_blocks - orig_start,
                                 orig_inode->i_ino, donor_inode->i_ino);
-                        *len = donor_inode->i_size - orig_start;
+                        *len = donor_blocks - orig_start;
                 }
         } else {
-                if (orig_start >= orig_inode->i_size) {
+                orig_blocks = (orig_inode->i_size + blocksize - 1) >> blkbits;
+                if (orig_start >= orig_blocks) {
                         ext4_debug("ext4 move extent: start offset [%llu] "
-                                "should be less than original file size "
-                                "[%lld] [inode:orig %lu, donor %lu]\n",
-                                 orig_start, orig_inode->i_size,
+                                "should be less than original file blocks "
+                                "[%u] [ino:orig %lu, donor %lu]\n",
+                                 orig_start, orig_blocks,
                                 orig_inode->i_ino, donor_inode->i_ino);
                         return -EINVAL;
                 }
 
-                if (orig_start + *len > orig_inode->i_size) {
+                if (orig_start + *len > orig_blocks) {
                         ext4_debug("ext4 move extent: Adjust length "
-                                "from %llu to %lld. Because it should be "
-                                "less than original file size "
+                                "from %llu to %llu. Because it should be "
+                                "less than original file blocks "
                                 "[ino:orig %lu, donor %lu]\n",
-                                *len, orig_inode->i_size - orig_start,
+                                *len, orig_blocks - orig_start,
                                 orig_inode->i_ino, donor_inode->i_ino);
-                        *len = orig_inode->i_size - orig_start;
+                        *len = orig_blocks - orig_start;
                 }
         }
 
@@ -1027,18 +1111,23 @@ mext_check_arguments(struct inode *orig_inode,
  * @inode1:     the inode structure
  * @inode2:     the inode structure
  *
- * Lock two inodes' i_mutex by i_ino order. This function is moved from
- * fs/inode.c.
+ * Lock two inodes' i_mutex by i_ino order.
+ * If inode1 or inode2 is NULL, return -EIO. Otherwise, return 0.
  */
-static void
+static int
 mext_inode_double_lock(struct inode *inode1, struct inode *inode2)
 {
-        if (inode1 == NULL || inode2 == NULL || inode1 == inode2) {
-                if (inode1)
-                        mutex_lock(&inode1->i_mutex);
-                else if (inode2)
-                        mutex_lock(&inode2->i_mutex);
-                return;
+        int ret = 0;
+
+        BUG_ON(inode1 == NULL && inode2 == NULL);
+
+        ret = mext_check_null_inode(inode1, inode2, __func__);
+        if (ret < 0)
+                goto out;
+
+        if (inode1 == inode2) {
+                mutex_lock(&inode1->i_mutex);
+                goto out;
         }
 
         if (inode1->i_ino < inode2->i_ino) {
@@ -1048,6 +1137,9 @@ mext_inode_double_lock(struct inode *inode1, struct inode *inode2)
                 mutex_lock_nested(&inode2->i_mutex, I_MUTEX_PARENT);
                 mutex_lock_nested(&inode1->i_mutex, I_MUTEX_CHILD);
         }
+
+out:
+        return ret;
 }
 
 /**
@@ -1056,17 +1148,28 @@ mext_inode_double_lock(struct inode *inode1, struct inode *inode2)
  * @inode1:     the inode that is released first
  * @inode2:     the inode that is released second
  *
- * This function is moved from fs/inode.c.
+ * If inode1 or inode2 is NULL, return -EIO. Otherwise, return 0.
  */
 
-static void
+static int
 mext_inode_double_unlock(struct inode *inode1, struct inode *inode2)
 {
+        int ret = 0;
+
+        BUG_ON(inode1 == NULL && inode2 == NULL);
+
+        ret = mext_check_null_inode(inode1, inode2, __func__);
+        if (ret < 0)
+                goto out;
+
         if (inode1)
                 mutex_unlock(&inode1->i_mutex);
 
         if (inode2 && inode2 != inode1)
                 mutex_unlock(&inode2->i_mutex);
+
+out:
+        return ret;
 }
 
 /**
@@ -1123,70 +1226,76 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp,
         ext4_lblk_t block_end, seq_start, add_blocks, file_end, seq_blocks = 0;
         ext4_lblk_t rest_blocks;
         pgoff_t orig_page_offset = 0, seq_end_page;
-        int ret, depth, last_extent = 0;
+        int ret1, ret2, depth, last_extent = 0;
         int blocks_per_page = PAGE_CACHE_SIZE >> orig_inode->i_blkbits;
         int data_offset_in_page;
         int block_len_in_page;
         int uninit;
 
         /* protect orig and donor against a truncate */
-        mext_inode_double_lock(orig_inode, donor_inode);
+        ret1 = mext_inode_double_lock(orig_inode, donor_inode);
+        if (ret1 < 0)
+                return ret1;
 
         mext_double_down_read(orig_inode, donor_inode);
         /* Check the filesystem environment whether move_extent can be done */
-        ret = mext_check_arguments(orig_inode, donor_inode, orig_start,
+        ret1 = mext_check_arguments(orig_inode, donor_inode, orig_start,
                                         donor_start, &len, *moved_len);
         mext_double_up_read(orig_inode, donor_inode);
-        if (ret)
-                goto out2;
+        if (ret1)
+                goto out;
 
         file_end = (i_size_read(orig_inode) - 1) >> orig_inode->i_blkbits;
         block_end = block_start + len - 1;
         if (file_end < block_end)
                 len -= block_end - file_end;
 
-        get_ext_path(orig_path, orig_inode, block_start, ret);
-        if (orig_path == NULL)
-                goto out2;
+        ret1 = get_ext_path(orig_inode, block_start, &orig_path);
+        if (ret1)
+                goto out;
 
         /* Get path structure to check the hole */
-        get_ext_path(holecheck_path, orig_inode, block_start, ret);
-        if (holecheck_path == NULL)
+        ret1 = get_ext_path(orig_inode, block_start, &holecheck_path);
+        if (ret1)
                 goto out;
 
         depth = ext_depth(orig_inode);
         ext_cur = holecheck_path[depth].p_ext;
-        if (ext_cur == NULL) {
-                ret = -EINVAL;
-                goto out;
-        }
 
         /*
-         * Get proper extent whose ee_block is beyond block_start
-         * if block_start was within the hole.
+         * Get proper starting location of block replacement if block_start was
+         * within the hole.
          */
         if (le32_to_cpu(ext_cur->ee_block) +
                 ext4_ext_get_actual_len(ext_cur) - 1 < block_start) {
+                /*
+                 * The hole exists between extents or the tail of
+                 * original file.
+                 */
                 last_extent = mext_next_extent(orig_inode,
                                         holecheck_path, &ext_cur);
                 if (last_extent < 0) {
-                        ret = last_extent;
+                        ret1 = last_extent;
                         goto out;
                 }
                 last_extent = mext_next_extent(orig_inode, orig_path,
                                                         &ext_dummy);
                 if (last_extent < 0) {
-                        ret = last_extent;
+                        ret1 = last_extent;
                         goto out;
                 }
-        }
-        seq_start = block_start;
+                seq_start = le32_to_cpu(ext_cur->ee_block);
+        } else if (le32_to_cpu(ext_cur->ee_block) > block_start)
+                /* The hole exists at the beginning of original file. */
+                seq_start = le32_to_cpu(ext_cur->ee_block);
+        else
+                seq_start = block_start;
 
         /* No blocks within the specified range. */
         if (le32_to_cpu(ext_cur->ee_block) > block_end) {
                 ext4_debug("ext4 move extent: The specified range of file "
                                                         "may be the hole\n");
-                ret = -EINVAL;
+                ret1 = -EINVAL;
                 goto out;
         }
 
@@ -1206,7 +1315,7 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp,
                 last_extent = mext_next_extent(orig_inode, holecheck_path,
                                                 &ext_cur);
                 if (last_extent < 0) {
-                        ret = last_extent;
+                        ret1 = last_extent;
                         break;
                 }
                 add_blocks = ext4_ext_get_actual_len(ext_cur);
@@ -1258,16 +1367,23 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp,
                 while (orig_page_offset <= seq_end_page) {
 
                         /* Swap original branches with new branches */
-                        ret = move_extent_par_page(o_filp, donor_inode,
+                        ret1 = move_extent_per_page(o_filp, donor_inode,
                                                 orig_page_offset,
                                                 data_offset_in_page,
                                                 block_len_in_page, uninit);
-                        if (ret < 0)
+                        if (ret1 < 0)
                                 goto out;
                         orig_page_offset++;
                         /* Count how many blocks we have exchanged */
                         *moved_len += block_len_in_page;
-                        BUG_ON(*moved_len > len);
+                        if (*moved_len > len) {
+                                ext4_error(orig_inode->i_sb, __func__,
+                                        "We replaced blocks too much! "
+                                        "sum of replaced: %llu requested: %llu",
+                                        *moved_len, len);
+                                ret1 = -EIO;
+                                goto out;
+                        }
 
                         data_offset_in_page = 0;
                         rest_blocks -= block_len_in_page;
@@ -1280,17 +1396,16 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp,
                 /* Decrease buffer counter */
                 if (holecheck_path)
                         ext4_ext_drop_refs(holecheck_path);
-                get_ext_path(holecheck_path, orig_inode,
-                                      seq_start, ret);
-                if (holecheck_path == NULL)
+                ret1 = get_ext_path(orig_inode, seq_start, &holecheck_path);
+                if (ret1)
                         break;
                 depth = holecheck_path->p_depth;
 
                 /* Decrease buffer counter */
                 if (orig_path)
                         ext4_ext_drop_refs(orig_path);
-                get_ext_path(orig_path, orig_inode, seq_start, ret);
-                if (orig_path == NULL)
+                ret1 = get_ext_path(orig_inode, seq_start, &orig_path);
+                if (ret1)
                         break;
 
                 ext_cur = holecheck_path[depth].p_ext;
@@ -1307,14 +1422,13 @@ out:
                 ext4_ext_drop_refs(holecheck_path);
                 kfree(holecheck_path);
         }
-out2:
-        mext_inode_double_unlock(orig_inode, donor_inode);
 
-        if (ret)
-                return ret;
+        ret2 = mext_inode_double_unlock(orig_inode, donor_inode);
 
-        /* All of the specified blocks must be exchanged in succeed */
-        BUG_ON(*moved_len != len);
+        if (ret1)
+                return ret1;
+        else if (ret2)
+                return ret2;
 
         return 0;
 }