ext4: improve writepage credit estimate for files with indirect blocks

[~andy/linux] / fs / ext4 / indirect.c

diff --git a/fs/ext4/indirect.c b/fs/ext4/indirect.c
index b8d5d351e24f64b1a5ee02bd90be59f5b19ce290..f7742f03cdcbea4a367115398ccd1d2df75dfa1e 100644 (file)
--- a/fs/ext4/indirect.c
+++ b/fs/ext4/indirect.c
@@ -779,27 +779,18 @@ int ext4_ind_calc_metadata_amount(struct inode *inode, sector_t lblock)
        return (blk_bits / EXT4_ADDR_PER_BLOCK_BITS(inode->i_sb)) + 1;
 }
 
-int ext4_ind_trans_blocks(struct inode *inode, int nrblocks, int chunk)
+/*
+ * Calculate number of indirect blocks touched by mapping @nrblocks logically
+ * contiguous blocks
+ */
+int ext4_ind_trans_blocks(struct inode *inode, int nrblocks)
 {
-       int indirects;
-
-       /* if nrblocks are contiguous */
-       if (chunk) {
-               /*
-                * With N contiguous data blocks, we need at most
-                * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) + 1 indirect blocks,
-                * 2 dindirect blocks, and 1 tindirect block
-                */
-               return DIV_ROUND_UP(nrblocks,
-                                   EXT4_ADDR_PER_BLOCK(inode->i_sb)) + 4;
-       }
        /*
-        * if nrblocks are not contiguous, worse case, each block touch
-        * a indirect block, and each indirect block touch a double indirect
-        * block, plus a triple indirect block
+        * With N contiguous data blocks, we need at most
+        * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) + 1 indirect blocks,
+        * 2 dindirect blocks, and 1 tindirect block
         */
-       indirects = nrblocks * 2 + 1;
-       return indirects;
+       return DIV_ROUND_UP(nrblocks, EXT4_ADDR_PER_BLOCK(inode->i_sb)) + 4;
 }
 
 /*