}
/*
- * ext4_ext_calc_credits_for_insert:
- * This routine returns max. credits that the extent tree can consume.
- * It should be OK for low-performance paths like ->writepage()
- * To allow many writing processes to fit into a single transaction,
- * the caller should calculate credits under i_data_sem and
- * pass the actual path.
+ * ext4_ext_calc_credits_for_single_extent:
+ * This routine returns max. credits that needed to insert an extent
+ * to the extent tree.
+ * When pass the actual path, the caller should calculate credits
+ * under i_data_sem.
*/
-int ext4_ext_calc_credits_for_insert(struct inode *inode,
+int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks,
struct ext4_ext_path *path)
{
- int depth, needed;
-
if (path) {
+ int depth = ext_depth(inode);
+ int ret = 0;
+
/* probably there is space in leaf? */
- depth = ext_depth(inode);
if (le16_to_cpu(path[depth].p_hdr->eh_entries)
- < le16_to_cpu(path[depth].p_hdr->eh_max))
- return 1;
- }
+ < le16_to_cpu(path[depth].p_hdr->eh_max)) {
- /*
- * given 32-bit logical block (4294967296 blocks), max. tree
- * can be 4 levels in depth -- 4 * 340^4 == 53453440000.
- * Let's also add one more level for imbalance.
- */
- depth = 5;
-
- /* allocation of new data block(s) */
- needed = 2;
+ /*
+ * There are some space in the leaf tree, no
+ * need to account for leaf block credit
+ *
+ * bitmaps and block group descriptor blocks
+ * and other metadat blocks still need to be
+ * accounted.
+ */
+ /* 1 bitmap, 1 block group descriptor */
+ ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb);
+ }
+ }
- /*
- * tree can be full, so it would need to grow in depth:
- * we need one credit to modify old root, credits for
- * new root will be added in split accounting
- */
- needed += 1;
+ return ext4_chunk_trans_blocks(inode, nrblocks);
+}
- /*
- * Index split can happen, we would need:
- * allocate intermediate indexes (bitmap + group)
- * + change two blocks at each level, but root (already included)
- */
- needed += (depth * 2) + (depth * 2);
+/*
+ * How many index/leaf blocks need to change/allocate to modify nrblocks?
+ *
+ * if nrblocks are fit in a single extent (chunk flag is 1), then
+ * in the worse case, each tree level index/leaf need to be changed
+ * if the tree split due to insert a new extent, then the old tree
+ * index/leaf need to be updated too
+ *
+ * If the nrblocks are discontiguous, they could cause
+ * the whole tree split more than once, but this is really rare.
+ */
+int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks, int chunk)
+{
+ int index;
+ int depth = ext_depth(inode);
- /* any allocation modifies superblock */
- needed += 1;
+ if (chunk)
+ index = depth * 2;
+ else
+ index = depth * 3;
- return needed;
+ return index;
}
static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
correct_index = 1;
credits += (ext_depth(inode)) + 1;
}
-#ifdef CONFIG_QUOTA
credits += 2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb);
-#endif
err = ext4_ext_journal_restart(handle, credits);
if (err)
/*
* probably first extent we're gonna free will be last in block
*/
- err = ext4_writepage_trans_blocks(inode) + 3;
+ err = ext4_writepage_trans_blocks(inode);
handle = ext4_journal_start(inode, err);
if (IS_ERR(handle))
return;
down_write(&EXT4_I(inode)->i_data_sem);
ext4_ext_invalidate_cache(inode);
- ext4_mb_discard_inode_preallocations(inode);
+ ext4_discard_reservation(inode);
/*
* TODO: optimization is possible here.
ext4_journal_stop(handle);
}
-/*
- * ext4_ext_writepage_trans_blocks:
- * calculate max number of blocks we could modify
- * in order to allocate new block for an inode
- */
-int ext4_ext_writepage_trans_blocks(struct inode *inode, int num)
-{
- int needed;
-
- needed = ext4_ext_calc_credits_for_insert(inode, NULL);
-
- /* caller wants to allocate num blocks, but note it includes sb */
- needed = needed * num - (num - 1);
-
-#ifdef CONFIG_QUOTA
- needed += 2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb);
-#endif
-
- return needed;
-}
-
static void ext4_falloc_update_inode(struct inode *inode,
int mode, loff_t new_size, int update_ctime)
{
max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits)
- block;
/*
- * credits to insert 1 extent into extent tree + buffers to be able to
- * modify 1 super block, 1 block bitmap and 1 group descriptor.
+ * credits to insert 1 extent into extent tree
*/
- credits = EXT4_DATA_TRANS_BLOCKS(inode->i_sb) + 3;
+ credits = ext4_chunk_trans_blocks(inode, max_blocks);
mutex_lock(&inode->i_mutex);
retry:
while (ret >= 0 && ret < max_blocks) {
projects / linux-2.6 / blobdiff