diff options
| author | NeilBrown <neilb@suse.com> | 2016-11-18 13:22:04 +1100 |
|---|---|---|
| committer | Shaohua Li <shli@fb.com> | 2016-11-18 09:32:50 -0800 |
| commit | 109e37653033a5fcd3bf8cab0ed6a7ff433f758a (patch) | |
| tree | 32abb5a663ded00ebe7bddbfb398ec617a9cb2dc /drivers/md/linear.c | |
| parent | 354b445b5f84f72e64cef9ffe175548e84c1a874 (diff) | |
| download | linux-109e37653033a5fcd3bf8cab0ed6a7ff433f758a.tar.bz2 | |
md: add block tracing for bio_remapping
The block tracing infrastructure (accessed with blktrace/blkparse)
supports the tracing of mapping bios from one device to another.
This is currently used when a bio in a partition is mapped to the
whole device, when bios are mapped by dm, and for mapping in md/raid5.
Other md personalities do not include this tracing yet, so add it.
When a read-error is detected we redirect the request to a different device.
This could justifiably be seen as a new mapping for the originial bio,
or a secondary mapping for the bio that errors. This patch uses
the second option.
When md is used under dm-raid, the mappings are not traced as we do
not have access to the block device number of the parent.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Diffstat (limited to 'drivers/md/linear.c')
| -rw-r--r-- | drivers/md/linear.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/drivers/md/linear.c b/drivers/md/linear.c index 9c7d4f5483ea..5975c9915684 100644 --- a/drivers/md/linear.c +++ b/drivers/md/linear.c @@ -21,6 +21,7 @@ #include <linux/seq_file.h> #include <linux/module.h> #include <linux/slab.h> +#include <trace/events/block.h> #include "md.h" #include "linear.h" @@ -227,22 +228,22 @@ static void linear_make_request(struct mddev *mddev, struct bio *bio) } do { - tmp_dev = which_dev(mddev, bio->bi_iter.bi_sector); + sector_t bio_sector = bio->bi_iter.bi_sector; + tmp_dev = which_dev(mddev, bio_sector); start_sector = tmp_dev->end_sector - tmp_dev->rdev->sectors; end_sector = tmp_dev->end_sector; data_offset = tmp_dev->rdev->data_offset; bio->bi_bdev = tmp_dev->rdev->bdev; - if (unlikely(bio->bi_iter.bi_sector >= end_sector || - bio->bi_iter.bi_sector < start_sector)) + if (unlikely(bio_sector >= end_sector || + bio_sector < start_sector)) goto out_of_bounds; if (unlikely(bio_end_sector(bio) > end_sector)) { /* This bio crosses a device boundary, so we have to * split it. */ - split = bio_split(bio, end_sector - - bio->bi_iter.bi_sector, + split = bio_split(bio, end_sector - bio_sector, GFP_NOIO, fs_bio_set); bio_chain(split, bio); } else { @@ -256,8 +257,13 @@ static void linear_make_request(struct mddev *mddev, struct bio *bio) !blk_queue_discard(bdev_get_queue(split->bi_bdev)))) { /* Just ignore it */ bio_endio(split); - } else + } else { + if (mddev->gendisk) + trace_block_bio_remap(bdev_get_queue(split->bi_bdev), + split, disk_devt(mddev->gendisk), + bio_sector); generic_make_request(split); + } } while (split != bio); return; |