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authorLinus Torvalds <torvalds@linux-foundation.org>2014-06-13 00:33:29 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2014-06-13 00:33:29 +0400
commit0e04c641b199435f3779454055f6a7de258ecdfc (patch)
tree9b79da0c52240bf4b96270ac12356ad75da6f739 /drivers/md/dm-snap.c
parent7550cfab3d4053b54f16e2fe337affde71d1eb51 (diff)
parent09869de57ed2728ae3c619803932a86cb0e2c4f8 (diff)
downloadlinux-0e04c641b199435f3779454055f6a7de258ecdfc.tar.xz
Merge tag 'dm-3.16-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device mapper updates from Mike Snitzer: "This pull request is later than I'd have liked because I was waiting for some performance data to help finally justify sending the long-standing dm-crypt cpu scalability improvements upstream. Unfortunately we came up short, so those dm-crypt changes will continue to wait, but it seems we're not far off. . Add dm_accept_partial_bio interface to DM core to allow DM targets to only process a portion of a bio, the remainder being sent in the next bio. This enables the old dm snapshot-origin target to only split write bios on chunk boundaries, read bios are now sent to the origin device unchanged. . Add DM core support for disabling WRITE SAME if the underlying SCSI layer disables it due to command failure. . Reduce lock contention in DM's bio-prison. . A few small cleanups and fixes to dm-thin and dm-era" * tag 'dm-3.16-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm thin: update discard_granularity to reflect the thin-pool blocksize dm bio prison: implement per bucket locking in the dm_bio_prison hash table dm: remove symbol export for dm_set_device_limits dm: disable WRITE SAME if it fails dm era: check for a non-NULL metadata object before closing it dm thin: return ENOSPC instead of EIO when error_if_no_space enabled dm thin: cleanup noflush_work to use a proper completion dm snapshot: do not split read bios sent to snapshot-origin target dm snapshot: allocate a per-target structure for snapshot-origin target dm: introduce dm_accept_partial_bio dm: change sector_count member in clone_info from sector_t to unsigned
Diffstat (limited to 'drivers/md/dm-snap.c')
-rw-r--r--drivers/md/dm-snap.c67
1 files changed, 48 insertions, 19 deletions
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index 8e0caed0bf74..5bd2290cfb1e 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -2141,6 +2141,11 @@ static int origin_write_extent(struct dm_snapshot *merging_snap,
* Origin: maps a linear range of a device, with hooks for snapshotting.
*/
+struct dm_origin {
+ struct dm_dev *dev;
+ unsigned split_boundary;
+};
+
/*
* Construct an origin mapping: <dev_path>
* The context for an origin is merely a 'struct dm_dev *'
@@ -2149,41 +2154,65 @@ static int origin_write_extent(struct dm_snapshot *merging_snap,
static int origin_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{
int r;
- struct dm_dev *dev;
+ struct dm_origin *o;
if (argc != 1) {
ti->error = "origin: incorrect number of arguments";
return -EINVAL;
}
- r = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &dev);
+ o = kmalloc(sizeof(struct dm_origin), GFP_KERNEL);
+ if (!o) {
+ ti->error = "Cannot allocate private origin structure";
+ r = -ENOMEM;
+ goto bad_alloc;
+ }
+
+ r = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &o->dev);
if (r) {
ti->error = "Cannot get target device";
- return r;
+ goto bad_open;
}
- ti->private = dev;
+ ti->private = o;
ti->num_flush_bios = 1;
return 0;
+
+bad_open:
+ kfree(o);
+bad_alloc:
+ return r;
}
static void origin_dtr(struct dm_target *ti)
{
- struct dm_dev *dev = ti->private;
- dm_put_device(ti, dev);
+ struct dm_origin *o = ti->private;
+ dm_put_device(ti, o->dev);
+ kfree(o);
}
static int origin_map(struct dm_target *ti, struct bio *bio)
{
- struct dm_dev *dev = ti->private;
- bio->bi_bdev = dev->bdev;
+ struct dm_origin *o = ti->private;
+ unsigned available_sectors;
- if (bio->bi_rw & REQ_FLUSH)
+ bio->bi_bdev = o->dev->bdev;
+
+ if (unlikely(bio->bi_rw & REQ_FLUSH))
return DM_MAPIO_REMAPPED;
+ if (bio_rw(bio) != WRITE)
+ return DM_MAPIO_REMAPPED;
+
+ available_sectors = o->split_boundary -
+ ((unsigned)bio->bi_iter.bi_sector & (o->split_boundary - 1));
+
+ if (bio_sectors(bio) > available_sectors)
+ dm_accept_partial_bio(bio, available_sectors);
+
/* Only tell snapshots if this is a write */
- return (bio_rw(bio) == WRITE) ? do_origin(dev, bio) : DM_MAPIO_REMAPPED;
+ return do_origin(o->dev, bio);
}
/*
@@ -2192,15 +2221,15 @@ static int origin_map(struct dm_target *ti, struct bio *bio)
*/
static void origin_resume(struct dm_target *ti)
{
- struct dm_dev *dev = ti->private;
+ struct dm_origin *o = ti->private;
- ti->max_io_len = get_origin_minimum_chunksize(dev->bdev);
+ o->split_boundary = get_origin_minimum_chunksize(o->dev->bdev);
}
static void origin_status(struct dm_target *ti, status_type_t type,
unsigned status_flags, char *result, unsigned maxlen)
{
- struct dm_dev *dev = ti->private;
+ struct dm_origin *o = ti->private;
switch (type) {
case STATUSTYPE_INFO:
@@ -2208,7 +2237,7 @@ static void origin_status(struct dm_target *ti, status_type_t type,
break;
case STATUSTYPE_TABLE:
- snprintf(result, maxlen, "%s", dev->name);
+ snprintf(result, maxlen, "%s", o->dev->name);
break;
}
}
@@ -2216,13 +2245,13 @@ static void origin_status(struct dm_target *ti, status_type_t type,
static int origin_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
struct bio_vec *biovec, int max_size)
{
- struct dm_dev *dev = ti->private;
- struct request_queue *q = bdev_get_queue(dev->bdev);
+ struct dm_origin *o = ti->private;
+ struct request_queue *q = bdev_get_queue(o->dev->bdev);
if (!q->merge_bvec_fn)
return max_size;
- bvm->bi_bdev = dev->bdev;
+ bvm->bi_bdev = o->dev->bdev;
return min(max_size, q->merge_bvec_fn(q, bvm, biovec));
}
@@ -2230,9 +2259,9 @@ static int origin_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
static int origin_iterate_devices(struct dm_target *ti,
iterate_devices_callout_fn fn, void *data)
{
- struct dm_dev *dev = ti->private;
+ struct dm_origin *o = ti->private;
- return fn(ti, dev, 0, ti->len, data);
+ return fn(ti, o->dev, 0, ti->len, data);
}
static struct target_type origin_target = {