Hi,
On Thu 25-11-10 15:27:09, Lukas Czerner wrote:
> > +/**
> > + * ext3_trim_fs() -- trim ioctl handle function
> > + * @sb: superblock for filesystem
> > + * @start: First Byte to trim
> > + * @len: number of Bytes to trim from start
> > + * @minlen: minimum extent length in Bytes
> > + *
> > + * ext3_trim_fs goes through all allocation groups containing Bytes from
> > + * start to start+len. For each such a group ext3_trim_all_free function
> > + * is invoked to trim all free space.
> > + */
> > +int ext3_trim_fs(struct super_block *sb, struct fstrim_range *range)
> > +{
> > + ext3_grpblk_t last_block, first_block, free_blocks;
> > + unsigned long first_group, last_group;
> > + unsigned long group, ngroups;
> > + struct ext3_group_desc *gdp;
> > + struct ext3_super_block *es;
> > + uint64_t start, len, minlen, trimmed;
> > + int ret = 0;
> We probably need to add this:
>
> ext3_fsblk_t blocks_count = le32_to_cpu(EXT3_SB(sb)->s_es->s_blocks_count);
>
> > +
> > + start = range->start >> sb->s_blocksize_bits;
> > + len = range->len >> sb->s_blocksize_bits;
> > + minlen = range->minlen >> sb->s_blocksize_bits;
> > + trimmed = 0;
> and this:
>
> if (len > blocks_count)
> len = blocks_count - start;
Thanks for letting me know. The above could go negative if start is too
big. So I've ended up with checks:
+ if (start >= max_blks)
+ goto out;
+ if (start + len > max_blks)
+ len = max_blks - start;
Honza
--
Jan Kara <jack@xxxxxxx>
SUSE Labs, CR
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