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    Subject[65/74] ext4: fix credits computing for indirect mapped files
    2.6.32-longterm review patch.  If anyone has any objections, please let us know.

    ------------------

    From: Yongqiang Yang <xiaoqiangnk@gmail.com>

    commit 5b41395fcc0265fc9f193aef9df39ce49d64677c upstream.

    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: Yongqiang Yang <xiaoqiangnk@gmail.com>
    Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
    Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

    ---
    fs/ext4/inode.c | 11 +++++------
    1 file changed, 5 insertions(+), 6 deletions(-)

    --- a/fs/ext4/inode.c
    +++ b/fs/ext4/inode.c
    @@ -5458,13 +5458,12 @@ static int ext4_indirect_trans_blocks(st
    /* 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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