On Fri, Oct 07, 2011 at 12:11:00AM -0700, Allison Henderson wrote:
> This patch adds a new ext4_ind_hole_lookup function that
> will be used to identify and skip over holes during a
> secure delete operation
>
> Signed-off-by: Allison Henderson <achender@xxxxxxxxxxxxxxxxxx>
> ---
> :100644 100644 db54ce4... 5c9f88c... M fs/ext4/ext4.h
> :100644 100644 0962642... 2fe9dfd... M fs/ext4/indirect.c
> :100644 100644 c4da98a... 9dc8c14... M fs/ext4/inode.c
> fs/ext4/ext4.h | 5 +++
> fs/ext4/indirect.c | 2 +-
> fs/ext4/inode.c | 73 ++++++++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 79 insertions(+), 1 deletions(-)
>
> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
> index db54ce4..5c9f88c 100644
> --- a/fs/ext4/ext4.h
> +++ b/fs/ext4/ext4.h
> @@ -2241,6 +2241,11 @@ extern int ext4_bio_write_page(struct ext4_io_submit *io,
> /* mmp.c */
> extern int ext4_multi_mount_protect(struct super_block *, ext4_fsblk_t);
>
> +/* indirects.c */
> +extern int ext4_block_to_path(struct inode *inode,
> + ext4_lblk_t i_block,
> + ext4_lblk_t offsets[4], int *boundary);
> +
> /* BH_Uninit flag: blocks are allocated but uninitialized on disk */
> enum ext4_state_bits {
> BH_Uninit /* blocks are allocated but uninitialized on disk */
> diff --git a/fs/ext4/indirect.c b/fs/ext4/indirect.c
> index 0962642..2fe9dfd 100644
> --- a/fs/ext4/indirect.c
> +++ b/fs/ext4/indirect.c
> @@ -69,7 +69,7 @@ static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)
> * get there at all.
> */
>
> -static int ext4_block_to_path(struct inode *inode,
> +int ext4_block_to_path(struct inode *inode,
> ext4_lblk_t i_block,
> ext4_lblk_t offsets[4], int *boundary)
> {
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index c4da98a..9dc8c14 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -640,6 +640,79 @@ struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode,
> return bh;
> }
>
> +/*
> + * ext4_in_hole_lookup
> + *
> + * Returns the size of the hole located at the given block up to
> + * the first boundry, or 0 if there is no hole. Returns negative on err.
boundary
> + */
> +static int ext4_ind_hole_lookup(struct inode *inode, ext4_lblk_t block)
> +{
> + struct super_block *sb = inode->i_sb;
> + struct buffer_head *bh;
> + ext4_lblk_t offsets[4];
> + ext4_lblk_t offset;
> + __le32 *children;
> + __le32 blk;
> + int blocks_to_boundary = 0;
> + int depth = 0;
> + int hole_size = 0;
> + unsigned int i, j;
> +
> + depth = ext4_block_to_path(inode, block, offsets, &blocks_to_boundary);
> +
> + if (depth == 0)
> + return 0;
> +
> + offset = offsets[0];
> + blk = EXT4_I(inode)->i_data[offset];
> + if (blk == 0) {
> + for (i = *offsets; i < EXT4_NDIR_BLOCKS; i++) {
> + if (EXT4_I(inode)->i_data[i] == 0)
> + hole_size++;
> + else
> + break;
> + }
> + return hole_size;
> + }
> +
> +
> + for (j = 1; j < depth; j++) {
> + offset = offsets[j];
> + bh = sb_getblk(sb, le32_to_cpu(blk));
> + if (unlikely(!bh))
> + return -EIO;
> +
> + if (!bh_uptodate_or_lock(bh)) {
> + if (bh_submit_read(bh) < 0) {
> + put_bh(bh);
> + return -EIO;
> + }
> + /* validate block references */
> + if (ext4_check_indirect_blockref(inode, bh)) {
> + put_bh(bh);
> + return -EIO;
> + }
> + }
> +
> + blk = ((__le32 *)bh->b_data)[offset];
> + /* Reader: end */
> + if (blk == 0) {
> + children = (__le32 *)(bh->b_data);
> + for (i = offset; i < offset +
> + blocks_to_boundary; i++) {
> + if (children[i] == 0)
> + hole_size++;
> + else
> + break;
> + }
Do you need a put_bh here somewhere?
--D
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