Commit 5b41395f authored by Yongqiang Yang's avatar Yongqiang Yang Committed by Theodore Ts'o

ext4: fix credits computing for indirect mapped files

When writing a contiguous set of blocks, two indirect blocks could be
needed depending on how the blocks are aligned, so we need to increase
the number of credits needed by one.

[ Also fixed a another bug which could further underestimate the
  number of journal credits needed by 1; the code was using integer
  division instead of DIV_ROUND_UP() -- tytso]
Signed-off-by: default avatarYongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
parent 21f97697
......@@ -5398,13 +5398,12 @@ static int ext4_indirect_trans_blocks(struct inode *inode, int nrblocks,
/* if nrblocks are contiguous */
if (chunk) {
/*
* With N contiguous data blocks, it need at most
* N/EXT4_ADDR_PER_BLOCK(inode->i_sb) indirect blocks
* 2 dindirect blocks
* 1 tindirect 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 / EXT4_ADDR_PER_BLOCK(inode->i_sb);
return indirects + 3;
return DIV_ROUND_UP(nrblocks,
EXT4_ADDR_PER_BLOCK(inode->i_sb)) + 4;
}
/*
* if nrblocks are not contiguous, worse case, each block touch
......
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