On Wed 04-09-24 14:29:24, Zhang Yi wrote:
> From: Zhang Yi <yi.zhang@xxxxxxxxxx>
>
> Now the beginning of all the five functions in ext4_fallocate() (punch
> hole, zero range, insert range, collapse range and normal fallocate) are
> almost the same, they need to hold i_rwsem and check the validity of
> input parameters, so move the holding of i_rwsem to ext4_fallocate()
> and factor out a common helper to check the input parameters can make
> the code more clear.
>
> Signed-off-by: Zhang Yi <yi.zhang@xxxxxxxxxx>
...
> +static int ext4_fallocate_check(struct inode *inode, int mode,
> + loff_t offset, loff_t len)
> +{
> + /* Currently except punch_hole, just for extent based files. */
> + if (!(mode & FALLOC_FL_PUNCH_HOLE) &&
> + !ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
> + return -EOPNOTSUPP;
> +
> + /*
> + * Insert range and collapse range works only on fs cluster size
> + * aligned regions.
> + */
> + if (mode & (FALLOC_FL_INSERT_RANGE | FALLOC_FL_COLLAPSE_RANGE) &&
> + !IS_ALIGNED(offset | len, EXT4_CLUSTER_SIZE(inode->i_sb)))
> + return -EINVAL;
> +
> + if (mode & FALLOC_FL_INSERT_RANGE) {
> + /* Collapse range, offset must be less than i_size */
> + if (offset >= inode->i_size)
> + return -EINVAL;
> + /* Check whether the maximum file size would be exceeded */
> + if (len > inode->i_sb->s_maxbytes - inode->i_size)
> + return -EFBIG;
> + } else if (mode & FALLOC_FL_COLLAPSE_RANGE) {
> + /*
> + * Insert range, there is no need to overlap collapse
> + * range with EOF, in which case it is effectively a
> + * truncate operation.
> + */
> + if (offset + len >= inode->i_size)
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
I don't think this helps. If the code is really shared, then the
factorization is good but here you have to do various checks what operation
we perform and in that case I don't think it really helps readability to
factor out checks into a common function.
Honza
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
