This patch adds the nilfs_sufile_trim_fs function, which takes a fstrim_range structure and calls blkdev_issue_discard for every clean segment in the specified range. The range is truncated to sector boundaries.
Signed-off-by: Andreas Rohner <[email protected]> --- fs/nilfs2/sufile.c | 144 +++++++++++++++++++++++++++++++++++++++++++++++++++++ fs/nilfs2/sufile.h | 1 + 2 files changed, 145 insertions(+) diff --git a/fs/nilfs2/sufile.c b/fs/nilfs2/sufile.c index 3127e9f..3605cc9 100644 --- a/fs/nilfs2/sufile.c +++ b/fs/nilfs2/sufile.c @@ -870,6 +870,150 @@ ssize_t nilfs_sufile_get_suinfo(struct inode *sufile, __u64 segnum, void *buf, } /** + * nilfs_sufile_trim_fs() - trim ioctl handle function + * @sufile: inode of segment usage file + * @range: fstrim_range structure + * + * start: First Byte to trim + * len: number of Bytes to trim from start + * minlen: minimum extent length in Bytes + * + * Decription: nilfs_sufile_trim_fs goes through all segments containing bytes + * from start to start+len. start is rounded up to the next sector boundary + * and start+len is rounded down. For each clean segment blkdev_issue_discard + * function is invoked to trim it. + * + * Return Value: On success, 0 is returned or negative error code, otherwise. + */ +int nilfs_sufile_trim_fs(struct inode *sufile, struct fstrim_range *range) +{ + struct the_nilfs *nilfs = sufile->i_sb->s_fs_info; + struct buffer_head *su_bh; + struct nilfs_segment_usage *su; + void *kaddr; + size_t n, i, susz = NILFS_MDT(sufile)->mi_entry_size; + sector_t seg_start, seg_end, real_start, real_end, + start = 0, nblocks = 0; + u64 segnum, end, minlen, trimmed = 0; + int ret = 0; + unsigned int sect_size, sects_per_block; + + sect_size = bdev_logical_block_size(nilfs->ns_bdev); + sects_per_block = (1 << nilfs->ns_blocksize_bits) / sect_size; + real_start = (range->start + sect_size - 1) / sect_size; + real_end = (range->start + range->len) / sect_size; + segnum = nilfs_get_segnum_of_block(nilfs, real_start / sects_per_block); + end = nilfs_get_segnum_of_block(nilfs, ((real_end + sects_per_block - 1) + / sects_per_block) + nilfs->ns_blocks_per_segment - 1); + minlen = range->minlen / sect_size; + + + if (end > nilfs->ns_nsegments) + end = nilfs->ns_nsegments; + if (segnum >= nilfs->ns_nsegments || end <= segnum) + goto out; + + down_read(&NILFS_MDT(sufile)->mi_sem); + + while (segnum < end) { + n = nilfs_sufile_segment_usages_in_block(sufile, segnum, + end - 1); + + ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0, + &su_bh); + if (ret < 0) { + if (ret != -ENOENT) + goto out_sem; + /* hole */ + segnum += n; + continue; + } + + kaddr = kmap_atomic(su_bh->b_page); + su = nilfs_sufile_block_get_segment_usage(sufile, segnum, + su_bh, kaddr); + for (i = 0; i < n; ++i, ++segnum, su = (void *)su + susz) { + if (!nilfs_segment_usage_clean(su)) + continue; + + nilfs_get_segment_range(nilfs, segnum, &seg_start, + &seg_end); + + if (!nblocks) { + /* start new extent */ + start = seg_start; + nblocks = seg_end - seg_start + 1; + continue; + } + + if (start + nblocks == seg_start) { + /* add to previous extent */ + nblocks += seg_end - seg_start + 1; + continue; + } + + /* discard previous extent */ + start *= sects_per_block; + nblocks *= sects_per_block; + if (start < real_start) { + nblocks -= real_start - start; + start = real_start; + } + if (start + nblocks > real_end) + nblocks = real_end - start; + + if (nblocks >= minlen) { + kunmap_atomic(kaddr); + + ret = blkdev_issue_discard(nilfs->ns_bdev, + start, nblocks, GFP_NOFS, 0); + if (ret < 0) { + put_bh(su_bh); + goto out_sem; + } + + trimmed += nblocks; + kaddr = kmap_atomic(su_bh->b_page); + su = nilfs_sufile_block_get_segment_usage( + sufile, segnum, su_bh, kaddr); + } + + /* start new extent */ + start = seg_start; + nblocks = seg_end - seg_start + 1; + } + kunmap_atomic(kaddr); + put_bh(su_bh); + } + + + if (nblocks) { + /* discard last extent */ + start *= sects_per_block; + nblocks *= sects_per_block; + if (start < real_start) { + nblocks -= real_start - start; + start = real_start; + } + if (start + nblocks > real_end) + nblocks = real_end - start; + + if (nblocks >= minlen) { + ret = blkdev_issue_discard(nilfs->ns_bdev, start, + nblocks, GFP_NOFS, 0); + if (!ret) + trimmed += nblocks; + } + } + +out_sem: + up_read(&NILFS_MDT(sufile)->mi_sem); +out: + range->len = trimmed * sect_size; + return ret; +} + +/** * nilfs_sufile_read - read or get sufile inode * @sb: super block instance * @susize: size of a segment usage entry diff --git a/fs/nilfs2/sufile.h b/fs/nilfs2/sufile.h index e84bc5b..2434abd 100644 --- a/fs/nilfs2/sufile.h +++ b/fs/nilfs2/sufile.h @@ -65,6 +65,7 @@ void nilfs_sufile_do_set_error(struct inode *, __u64, struct buffer_head *, int nilfs_sufile_resize(struct inode *sufile, __u64 newnsegs); int nilfs_sufile_read(struct super_block *sb, size_t susize, struct nilfs_inode *raw_inode, struct inode **inodep); +int nilfs_sufile_trim_fs(struct inode *sufile, struct fstrim_range *range); /** * nilfs_sufile_scrap - make a segment garbage -- 1.9.0 -- To unsubscribe from this list: send the line "unsubscribe linux-nilfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
