forked from Minki/linux
1e1a4e8f43
Pull device mapper update from Mike Snitzer: - a couple small cleanups in dm-cache, dm-verity, persistent-data's dm-btree, and DM core. - a 4.1-stable fix for dm-cache that fixes the leaking of deferred bio prison cells - a 4.2-stable fix that adds feature reporting for the dm-stats features added in 4.2 - improve DM-snapshot to not invalidate the on-disk snapshot if snapshot device write overflow occurs; but a write overflow triggered through the origin device will still invalidate the snapshot. - optimize DM-thinp's async discard submission a bit now that late bio splitting has been included in block core. - switch DM-cache's SMQ policy lock from using a mutex to a spinlock; improves performance on very low latency devices (eg. NVMe SSD). - document DM RAID 4/5/6's discard support [ I did not pull the slab changes, which weren't appropriate for this tree, and weren't obviously the right thing to do anyway. At the very least they need some discussion and explanation before getting merged. Because not pulling the actual tagged commit but doing a partial pull instead, this merge commit thus also obviously is missing the git signature from the original tag ] * tag 'dm-4.3-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm cache: fix use after freeing migrations dm cache: small cleanups related to deferred prison cell cleanup dm cache: fix leaking of deferred bio prison cells dm raid: document RAID 4/5/6 discard support dm stats: report precise_timestamps and histogram in @stats_list output dm thin: optimize async discard submission dm snapshot: don't invalidate on-disk image on snapshot write overflow dm: remove unlikely() before IS_ERR() dm: do not override error code returned from dm_get_device() dm: test return value for DM_MAPIO_SUBMITTED dm verity: remove unused mempool dm cache: move wake_waker() from free_migrations() to where it is needed dm btree remove: remove unused function get_nr_entries() dm btree: remove unused "dm_block_t root" parameter in btree_split_sibling() dm cache policy smq: change the mutex to a spinlock
434 lines
9.5 KiB
C
434 lines
9.5 KiB
C
/*
|
|
* Copyright (C) 2003 Sistina Software (UK) Limited.
|
|
* Copyright (C) 2004, 2010-2011 Red Hat, Inc. All rights reserved.
|
|
*
|
|
* This file is released under the GPL.
|
|
*/
|
|
|
|
#include <linux/device-mapper.h>
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/init.h>
|
|
#include <linux/blkdev.h>
|
|
#include <linux/bio.h>
|
|
#include <linux/slab.h>
|
|
|
|
#define DM_MSG_PREFIX "flakey"
|
|
|
|
#define all_corrupt_bio_flags_match(bio, fc) \
|
|
(((bio)->bi_rw & (fc)->corrupt_bio_flags) == (fc)->corrupt_bio_flags)
|
|
|
|
/*
|
|
* Flakey: Used for testing only, simulates intermittent,
|
|
* catastrophic device failure.
|
|
*/
|
|
struct flakey_c {
|
|
struct dm_dev *dev;
|
|
unsigned long start_time;
|
|
sector_t start;
|
|
unsigned up_interval;
|
|
unsigned down_interval;
|
|
unsigned long flags;
|
|
unsigned corrupt_bio_byte;
|
|
unsigned corrupt_bio_rw;
|
|
unsigned corrupt_bio_value;
|
|
unsigned corrupt_bio_flags;
|
|
};
|
|
|
|
enum feature_flag_bits {
|
|
DROP_WRITES
|
|
};
|
|
|
|
struct per_bio_data {
|
|
bool bio_submitted;
|
|
};
|
|
|
|
static int parse_features(struct dm_arg_set *as, struct flakey_c *fc,
|
|
struct dm_target *ti)
|
|
{
|
|
int r;
|
|
unsigned argc;
|
|
const char *arg_name;
|
|
|
|
static struct dm_arg _args[] = {
|
|
{0, 6, "Invalid number of feature args"},
|
|
{1, UINT_MAX, "Invalid corrupt bio byte"},
|
|
{0, 255, "Invalid corrupt value to write into bio byte (0-255)"},
|
|
{0, UINT_MAX, "Invalid corrupt bio flags mask"},
|
|
};
|
|
|
|
/* No feature arguments supplied. */
|
|
if (!as->argc)
|
|
return 0;
|
|
|
|
r = dm_read_arg_group(_args, as, &argc, &ti->error);
|
|
if (r)
|
|
return r;
|
|
|
|
while (argc) {
|
|
arg_name = dm_shift_arg(as);
|
|
argc--;
|
|
|
|
/*
|
|
* drop_writes
|
|
*/
|
|
if (!strcasecmp(arg_name, "drop_writes")) {
|
|
if (test_and_set_bit(DROP_WRITES, &fc->flags)) {
|
|
ti->error = "Feature drop_writes duplicated";
|
|
return -EINVAL;
|
|
}
|
|
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* corrupt_bio_byte <Nth_byte> <direction> <value> <bio_flags>
|
|
*/
|
|
if (!strcasecmp(arg_name, "corrupt_bio_byte")) {
|
|
if (!argc) {
|
|
ti->error = "Feature corrupt_bio_byte requires parameters";
|
|
return -EINVAL;
|
|
}
|
|
|
|
r = dm_read_arg(_args + 1, as, &fc->corrupt_bio_byte, &ti->error);
|
|
if (r)
|
|
return r;
|
|
argc--;
|
|
|
|
/*
|
|
* Direction r or w?
|
|
*/
|
|
arg_name = dm_shift_arg(as);
|
|
if (!strcasecmp(arg_name, "w"))
|
|
fc->corrupt_bio_rw = WRITE;
|
|
else if (!strcasecmp(arg_name, "r"))
|
|
fc->corrupt_bio_rw = READ;
|
|
else {
|
|
ti->error = "Invalid corrupt bio direction (r or w)";
|
|
return -EINVAL;
|
|
}
|
|
argc--;
|
|
|
|
/*
|
|
* Value of byte (0-255) to write in place of correct one.
|
|
*/
|
|
r = dm_read_arg(_args + 2, as, &fc->corrupt_bio_value, &ti->error);
|
|
if (r)
|
|
return r;
|
|
argc--;
|
|
|
|
/*
|
|
* Only corrupt bios with these flags set.
|
|
*/
|
|
r = dm_read_arg(_args + 3, as, &fc->corrupt_bio_flags, &ti->error);
|
|
if (r)
|
|
return r;
|
|
argc--;
|
|
|
|
continue;
|
|
}
|
|
|
|
ti->error = "Unrecognised flakey feature requested";
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (test_bit(DROP_WRITES, &fc->flags) && (fc->corrupt_bio_rw == WRITE)) {
|
|
ti->error = "drop_writes is incompatible with corrupt_bio_byte with the WRITE flag set";
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Construct a flakey mapping:
|
|
* <dev_path> <offset> <up interval> <down interval> [<#feature args> [<arg>]*]
|
|
*
|
|
* Feature args:
|
|
* [drop_writes]
|
|
* [corrupt_bio_byte <Nth_byte> <direction> <value> <bio_flags>]
|
|
*
|
|
* Nth_byte starts from 1 for the first byte.
|
|
* Direction is r for READ or w for WRITE.
|
|
* bio_flags is ignored if 0.
|
|
*/
|
|
static int flakey_ctr(struct dm_target *ti, unsigned int argc, char **argv)
|
|
{
|
|
static struct dm_arg _args[] = {
|
|
{0, UINT_MAX, "Invalid up interval"},
|
|
{0, UINT_MAX, "Invalid down interval"},
|
|
};
|
|
|
|
int r;
|
|
struct flakey_c *fc;
|
|
unsigned long long tmpll;
|
|
struct dm_arg_set as;
|
|
const char *devname;
|
|
char dummy;
|
|
|
|
as.argc = argc;
|
|
as.argv = argv;
|
|
|
|
if (argc < 4) {
|
|
ti->error = "Invalid argument count";
|
|
return -EINVAL;
|
|
}
|
|
|
|
fc = kzalloc(sizeof(*fc), GFP_KERNEL);
|
|
if (!fc) {
|
|
ti->error = "Cannot allocate context";
|
|
return -ENOMEM;
|
|
}
|
|
fc->start_time = jiffies;
|
|
|
|
devname = dm_shift_arg(&as);
|
|
|
|
r = -EINVAL;
|
|
if (sscanf(dm_shift_arg(&as), "%llu%c", &tmpll, &dummy) != 1) {
|
|
ti->error = "Invalid device sector";
|
|
goto bad;
|
|
}
|
|
fc->start = tmpll;
|
|
|
|
r = dm_read_arg(_args, &as, &fc->up_interval, &ti->error);
|
|
if (r)
|
|
goto bad;
|
|
|
|
r = dm_read_arg(_args, &as, &fc->down_interval, &ti->error);
|
|
if (r)
|
|
goto bad;
|
|
|
|
if (!(fc->up_interval + fc->down_interval)) {
|
|
ti->error = "Total (up + down) interval is zero";
|
|
goto bad;
|
|
}
|
|
|
|
if (fc->up_interval + fc->down_interval < fc->up_interval) {
|
|
ti->error = "Interval overflow";
|
|
goto bad;
|
|
}
|
|
|
|
r = parse_features(&as, fc, ti);
|
|
if (r)
|
|
goto bad;
|
|
|
|
r = dm_get_device(ti, devname, dm_table_get_mode(ti->table), &fc->dev);
|
|
if (r) {
|
|
ti->error = "Device lookup failed";
|
|
goto bad;
|
|
}
|
|
|
|
ti->num_flush_bios = 1;
|
|
ti->num_discard_bios = 1;
|
|
ti->per_bio_data_size = sizeof(struct per_bio_data);
|
|
ti->private = fc;
|
|
return 0;
|
|
|
|
bad:
|
|
kfree(fc);
|
|
return r;
|
|
}
|
|
|
|
static void flakey_dtr(struct dm_target *ti)
|
|
{
|
|
struct flakey_c *fc = ti->private;
|
|
|
|
dm_put_device(ti, fc->dev);
|
|
kfree(fc);
|
|
}
|
|
|
|
static sector_t flakey_map_sector(struct dm_target *ti, sector_t bi_sector)
|
|
{
|
|
struct flakey_c *fc = ti->private;
|
|
|
|
return fc->start + dm_target_offset(ti, bi_sector);
|
|
}
|
|
|
|
static void flakey_map_bio(struct dm_target *ti, struct bio *bio)
|
|
{
|
|
struct flakey_c *fc = ti->private;
|
|
|
|
bio->bi_bdev = fc->dev->bdev;
|
|
if (bio_sectors(bio))
|
|
bio->bi_iter.bi_sector =
|
|
flakey_map_sector(ti, bio->bi_iter.bi_sector);
|
|
}
|
|
|
|
static void corrupt_bio_data(struct bio *bio, struct flakey_c *fc)
|
|
{
|
|
unsigned bio_bytes = bio_cur_bytes(bio);
|
|
char *data = bio_data(bio);
|
|
|
|
/*
|
|
* Overwrite the Nth byte of the data returned.
|
|
*/
|
|
if (data && bio_bytes >= fc->corrupt_bio_byte) {
|
|
data[fc->corrupt_bio_byte - 1] = fc->corrupt_bio_value;
|
|
|
|
DMDEBUG("Corrupting data bio=%p by writing %u to byte %u "
|
|
"(rw=%c bi_rw=%lu bi_sector=%llu cur_bytes=%u)\n",
|
|
bio, fc->corrupt_bio_value, fc->corrupt_bio_byte,
|
|
(bio_data_dir(bio) == WRITE) ? 'w' : 'r', bio->bi_rw,
|
|
(unsigned long long)bio->bi_iter.bi_sector, bio_bytes);
|
|
}
|
|
}
|
|
|
|
static int flakey_map(struct dm_target *ti, struct bio *bio)
|
|
{
|
|
struct flakey_c *fc = ti->private;
|
|
unsigned elapsed;
|
|
struct per_bio_data *pb = dm_per_bio_data(bio, sizeof(struct per_bio_data));
|
|
pb->bio_submitted = false;
|
|
|
|
/* Are we alive ? */
|
|
elapsed = (jiffies - fc->start_time) / HZ;
|
|
if (elapsed % (fc->up_interval + fc->down_interval) >= fc->up_interval) {
|
|
/*
|
|
* Flag this bio as submitted while down.
|
|
*/
|
|
pb->bio_submitted = true;
|
|
|
|
/*
|
|
* Map reads as normal.
|
|
*/
|
|
if (bio_data_dir(bio) == READ)
|
|
goto map_bio;
|
|
|
|
/*
|
|
* Drop writes?
|
|
*/
|
|
if (test_bit(DROP_WRITES, &fc->flags)) {
|
|
bio_endio(bio);
|
|
return DM_MAPIO_SUBMITTED;
|
|
}
|
|
|
|
/*
|
|
* Corrupt matching writes.
|
|
*/
|
|
if (fc->corrupt_bio_byte && (fc->corrupt_bio_rw == WRITE)) {
|
|
if (all_corrupt_bio_flags_match(bio, fc))
|
|
corrupt_bio_data(bio, fc);
|
|
goto map_bio;
|
|
}
|
|
|
|
/*
|
|
* By default, error all I/O.
|
|
*/
|
|
return -EIO;
|
|
}
|
|
|
|
map_bio:
|
|
flakey_map_bio(ti, bio);
|
|
|
|
return DM_MAPIO_REMAPPED;
|
|
}
|
|
|
|
static int flakey_end_io(struct dm_target *ti, struct bio *bio, int error)
|
|
{
|
|
struct flakey_c *fc = ti->private;
|
|
struct per_bio_data *pb = dm_per_bio_data(bio, sizeof(struct per_bio_data));
|
|
|
|
/*
|
|
* Corrupt successful READs while in down state.
|
|
* If flags were specified, only corrupt those that match.
|
|
*/
|
|
if (fc->corrupt_bio_byte && !error && pb->bio_submitted &&
|
|
(bio_data_dir(bio) == READ) && (fc->corrupt_bio_rw == READ) &&
|
|
all_corrupt_bio_flags_match(bio, fc))
|
|
corrupt_bio_data(bio, fc);
|
|
|
|
return error;
|
|
}
|
|
|
|
static void flakey_status(struct dm_target *ti, status_type_t type,
|
|
unsigned status_flags, char *result, unsigned maxlen)
|
|
{
|
|
unsigned sz = 0;
|
|
struct flakey_c *fc = ti->private;
|
|
unsigned drop_writes;
|
|
|
|
switch (type) {
|
|
case STATUSTYPE_INFO:
|
|
result[0] = '\0';
|
|
break;
|
|
|
|
case STATUSTYPE_TABLE:
|
|
DMEMIT("%s %llu %u %u ", fc->dev->name,
|
|
(unsigned long long)fc->start, fc->up_interval,
|
|
fc->down_interval);
|
|
|
|
drop_writes = test_bit(DROP_WRITES, &fc->flags);
|
|
DMEMIT("%u ", drop_writes + (fc->corrupt_bio_byte > 0) * 5);
|
|
|
|
if (drop_writes)
|
|
DMEMIT("drop_writes ");
|
|
|
|
if (fc->corrupt_bio_byte)
|
|
DMEMIT("corrupt_bio_byte %u %c %u %u ",
|
|
fc->corrupt_bio_byte,
|
|
(fc->corrupt_bio_rw == WRITE) ? 'w' : 'r',
|
|
fc->corrupt_bio_value, fc->corrupt_bio_flags);
|
|
|
|
break;
|
|
}
|
|
}
|
|
|
|
static int flakey_ioctl(struct dm_target *ti, unsigned int cmd, unsigned long arg)
|
|
{
|
|
struct flakey_c *fc = ti->private;
|
|
struct dm_dev *dev = fc->dev;
|
|
int r = 0;
|
|
|
|
/*
|
|
* Only pass ioctls through if the device sizes match exactly.
|
|
*/
|
|
if (fc->start ||
|
|
ti->len != i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT)
|
|
r = scsi_verify_blk_ioctl(NULL, cmd);
|
|
|
|
return r ? : __blkdev_driver_ioctl(dev->bdev, dev->mode, cmd, arg);
|
|
}
|
|
|
|
static int flakey_iterate_devices(struct dm_target *ti, iterate_devices_callout_fn fn, void *data)
|
|
{
|
|
struct flakey_c *fc = ti->private;
|
|
|
|
return fn(ti, fc->dev, fc->start, ti->len, data);
|
|
}
|
|
|
|
static struct target_type flakey_target = {
|
|
.name = "flakey",
|
|
.version = {1, 3, 1},
|
|
.module = THIS_MODULE,
|
|
.ctr = flakey_ctr,
|
|
.dtr = flakey_dtr,
|
|
.map = flakey_map,
|
|
.end_io = flakey_end_io,
|
|
.status = flakey_status,
|
|
.ioctl = flakey_ioctl,
|
|
.iterate_devices = flakey_iterate_devices,
|
|
};
|
|
|
|
static int __init dm_flakey_init(void)
|
|
{
|
|
int r = dm_register_target(&flakey_target);
|
|
|
|
if (r < 0)
|
|
DMERR("register failed %d", r);
|
|
|
|
return r;
|
|
}
|
|
|
|
static void __exit dm_flakey_exit(void)
|
|
{
|
|
dm_unregister_target(&flakey_target);
|
|
}
|
|
|
|
/* Module hooks */
|
|
module_init(dm_flakey_init);
|
|
module_exit(dm_flakey_exit);
|
|
|
|
MODULE_DESCRIPTION(DM_NAME " flakey target");
|
|
MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
|
|
MODULE_LICENSE("GPL");
|