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dm: refactor ioctl handling

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This moves the call to blkdev_ioctl and the argument checking to DM core
code, and only leaves a callout to find the block device to operate on
in the targets.  This simplifies the code and allows us to pass through
ioctl-like command using other methods in the next patch.

Also split out a helper around calling the prepare_ioctl method that
will be reused for persistent reservation handling.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This commit is contained in:
Christoph Hellwig 2015-10-15 14:10:50 +02:00 committed by Mike Snitzer
parent 47796938c4
commit e56f81e0b0
8 changed files with 94 additions and 75 deletions
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16
drivers/md/dm-flakey.c
View File

@ -373,20 +373,20 @@ static void flakey_status(struct dm_target *ti, status_type_t type,
}
}
static int flakey_ioctl(struct dm_target *ti, unsigned int cmd, unsigned long arg)
static int flakey_prepare_ioctl(struct dm_target *ti,
struct block_device **bdev, fmode_t *mode)
{
struct flakey_c *fc = ti->private;
struct dm_dev *dev = fc->dev;
int r = 0;
*bdev = fc->dev->bdev;
/*
* 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);
ti->len != i_size_read((*bdev)->bd_inode) >> SECTOR_SHIFT)
return 1;
return 0;
}
static int flakey_iterate_devices(struct dm_target *ti, iterate_devices_callout_fn fn, void *data)
@ -405,7 +405,7 @@ static struct target_type flakey_target = {
.map = flakey_map,
.end_io = flakey_end_io,
.status = flakey_status,
.ioctl = flakey_ioctl,
.prepare_ioctl = flakey_prepare_ioctl,
.iterate_devices = flakey_iterate_devices,
};

14
drivers/md/dm-linear.c
View File

@ -116,21 +116,21 @@ static void linear_status(struct dm_target *ti, status_type_t type,
}
}
static int linear_ioctl(struct dm_target *ti, unsigned int cmd,
unsigned long arg)
static int linear_prepare_ioctl(struct dm_target *ti,
struct block_device **bdev, fmode_t *mode)
{
struct linear_c *lc = (struct linear_c *) ti->private;
struct dm_dev *dev = lc->dev;
int r = 0;
*bdev = dev->bdev;
/*
* Only pass ioctls through if the device sizes match exactly.
*/
if (lc->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);
return 1;
return 0;
}
static int linear_iterate_devices(struct dm_target *ti,
@ -149,7 +149,7 @@ static struct target_type linear_target = {
.dtr = linear_dtr,
.map = linear_map,
.status = linear_status,
.ioctl = linear_ioctl,
.prepare_ioctl = linear_prepare_ioctl,
.iterate_devices = linear_iterate_devices,
};

13
drivers/md/dm-log-writes.c
View File

@ -714,20 +714,19 @@ static void log_writes_status(struct dm_target *ti, status_type_t type,
}
}
static int log_writes_ioctl(struct dm_target *ti, unsigned int cmd,
unsigned long arg)
static int log_writes_prepare_ioctl(struct dm_target *ti,
struct block_device **bdev, fmode_t *mode)
{
struct log_writes_c *lc = ti->private;
struct dm_dev *dev = lc->dev;
int r = 0;
*bdev = dev->bdev;
/*
* Only pass ioctls through if the device sizes match exactly.
*/
if (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);
return 1;
return 0;
}
static int log_writes_iterate_devices(struct dm_target *ti,
@ -782,7 +781,7 @@ static struct target_type log_writes_target = {
.map = log_writes_map,
.end_io = normal_end_io,
.status = log_writes_status,
.ioctl = log_writes_ioctl,
.prepare_ioctl = log_writes_prepare_ioctl,
.message = log_writes_message,
.iterate_devices = log_writes_iterate_devices,
.io_hints = log_writes_io_hints,

29
drivers/md/dm-mpath.c
View File

@ -1533,18 +1533,14 @@ out:
return r;
}
static int multipath_ioctl(struct dm_target *ti, unsigned int cmd,
unsigned long arg)
static int multipath_prepare_ioctl(struct dm_target *ti,
struct block_device **bdev, fmode_t *mode)
{
struct multipath *m = ti->private;
struct pgpath *pgpath;
struct block_device *bdev;
fmode_t mode;
unsigned long flags;
int r;
bdev = NULL;
mode = 0;
r = 0;
spin_lock_irqsave(&m->lock, flags);
@ -1555,23 +1551,17 @@ static int multipath_ioctl(struct dm_target *ti, unsigned int cmd,
pgpath = m->current_pgpath;
if (pgpath) {
bdev = pgpath->path.dev->bdev;
mode = pgpath->path.dev->mode;
*bdev = pgpath->path.dev->bdev;
*mode = pgpath->path.dev->mode;
}
if ((pgpath && m->queue_io) || (!pgpath && m->queue_if_no_path))
r = -ENOTCONN;
else if (!bdev)
else if (!*bdev)
r = -EIO;
spin_unlock_irqrestore(&m->lock, flags);
/*
* Only pass ioctls through if the device sizes match exactly.
*/
if (!r && ti->len != i_size_read(bdev->bd_inode) >> SECTOR_SHIFT)
r = scsi_verify_blk_ioctl(NULL, cmd);
if (r == -ENOTCONN && !fatal_signal_pending(current)) {
spin_lock_irqsave(&m->lock, flags);
if (!m->current_pg) {
@ -1584,7 +1574,12 @@ static int multipath_ioctl(struct dm_target *ti, unsigned int cmd,
dm_table_run_md_queue_async(m->ti->table);
}
return r ? : __blkdev_driver_ioctl(bdev, mode, cmd, arg);
/*
* Only pass ioctls through if the device sizes match exactly.
*/
if (!r && ti->len != i_size_read((*bdev)->bd_inode) >> SECTOR_SHIFT)
return 1;
return r;
}
static int multipath_iterate_devices(struct dm_target *ti,
@ -1700,7 +1695,7 @@ static struct target_type multipath_target = {
.resume = multipath_resume,
.status = multipath_status,
.message = multipath_message,
.ioctl = multipath_ioctl,
.prepare_ioctl = multipath_prepare_ioctl,
.iterate_devices = multipath_iterate_devices,
.busy = multipath_busy,
};

21
drivers/md/dm-switch.c
View File

@ -511,27 +511,24 @@ static void switch_status(struct dm_target *ti, status_type_t type,
*
* Passthrough all ioctls to the path for sector 0
*/
static int switch_ioctl(struct dm_target *ti, unsigned cmd,
unsigned long arg)
static int switch_prepare_ioctl(struct dm_target *ti,
struct block_device **bdev, fmode_t *mode)
{
struct switch_ctx *sctx = ti->private;
struct block_device *bdev;
fmode_t mode;
unsigned path_nr;
int r = 0;
path_nr = switch_get_path_nr(sctx, 0);
bdev = sctx->path_list[path_nr].dmdev->bdev;
mode = sctx->path_list[path_nr].dmdev->mode;
*bdev = sctx->path_list[path_nr].dmdev->bdev;
*mode = sctx->path_list[path_nr].dmdev->mode;
/*
* Only pass ioctls through if the device sizes match exactly.
*/
if (ti->len + sctx->path_list[path_nr].start != i_size_read(bdev->bd_inode) >> SECTOR_SHIFT)
r = scsi_verify_blk_ioctl(NULL, cmd);
return r ? : __blkdev_driver_ioctl(bdev, mode, cmd, arg);
if (ti->len + sctx->path_list[path_nr].start !=
i_size_read((*bdev)->bd_inode) >> SECTOR_SHIFT)
return 1;
return 0;
}
static int switch_iterate_devices(struct dm_target *ti,
@ -560,7 +557,7 @@ static struct target_type switch_target = {
.map = switch_map,
.message = switch_message,
.status = switch_status,
.ioctl = switch_ioctl,
.prepare_ioctl = switch_prepare_ioctl,
.iterate_devices = switch_iterate_devices,
};

15
drivers/md/dm-verity.c
View File

@ -631,18 +631,17 @@ static void verity_status(struct dm_target *ti, status_type_t type,
}
}
static int verity_ioctl(struct dm_target *ti, unsigned cmd,
unsigned long arg)
static int verity_prepare_ioctl(struct dm_target *ti,
struct block_device **bdev, fmode_t *mode)
{
struct dm_verity *v = ti->private;
int r = 0;
*bdev = v->data_dev->bdev;
if (v->data_start ||
ti->len != i_size_read(v->data_dev->bdev->bd_inode) >> SECTOR_SHIFT)
r = scsi_verify_blk_ioctl(NULL, cmd);
return r ? : __blkdev_driver_ioctl(v->data_dev->bdev, v->data_dev->mode,
cmd, arg);
return 1;
return 0;
}
static int verity_iterate_devices(struct dm_target *ti,
@ -965,7 +964,7 @@ static struct target_type verity_target = {
.dtr = verity_dtr,
.map = verity_map,
.status = verity_status,
.ioctl = verity_ioctl,
.prepare_ioctl = verity_prepare_ioctl,
.iterate_devices = verity_iterate_devices,
.io_hints = verity_io_hints,
};

55
drivers/md/dm.c
View File

@ -555,18 +555,16 @@ static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
return dm_get_geometry(md, geo);
}
static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode,
unsigned int cmd, unsigned long arg)
static int dm_get_live_table_for_ioctl(struct mapped_device *md,
struct dm_target **tgt, struct block_device **bdev,
fmode_t *mode, int *srcu_idx)
{
struct mapped_device *md = bdev->bd_disk->private_data;
int srcu_idx;
struct dm_table *map;
struct dm_target *tgt;
int r = -ENOTTY;
int r;
retry:
map = dm_get_live_table(md, &srcu_idx);
r = -ENOTTY;
map = dm_get_live_table(md, srcu_idx);
if (!map || !dm_table_get_size(map))
goto out;
@ -574,8 +572,9 @@ retry:
if (dm_table_get_num_targets(map) != 1)
goto out;
tgt = dm_table_get_target(map, 0);
if (!tgt->type->ioctl)
*tgt = dm_table_get_target(map, 0);
if (!(*tgt)->type->prepare_ioctl)
goto out;
if (dm_suspended_md(md)) {
@ -583,16 +582,46 @@ retry:
goto out;
}
r = tgt->type->ioctl(tgt, cmd, arg);
r = (*tgt)->type->prepare_ioctl(*tgt, bdev, mode);
if (r < 0)
goto out;
return r;
out:
dm_put_live_table(md, srcu_idx);
dm_put_live_table(md, *srcu_idx);
if (r == -ENOTCONN) {
msleep(10);
goto retry;
}
return r;
}
static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode,
unsigned int cmd, unsigned long arg)
{
struct mapped_device *md = bdev->bd_disk->private_data;
struct dm_target *tgt;
int srcu_idx, r;
r = dm_get_live_table_for_ioctl(md, &tgt, &bdev, &mode, &srcu_idx);
if (r < 0)
return r;
if (r > 0) {
/*
* Target determined this ioctl is being issued against
* a logical partition of the parent bdev; so extra
* validation is needed.
*/
r = scsi_verify_blk_ioctl(NULL, cmd);
if (r)
goto out;
}
r = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
out:
dm_put_live_table(md, srcu_idx);
return r;
}

6
include/linux/device-mapper.h
View File

@ -79,8 +79,8 @@ typedef void (*dm_status_fn) (struct dm_target *ti, status_type_t status_type,
typedef int (*dm_message_fn) (struct dm_target *ti, unsigned argc, char **argv);
typedef int (*dm_ioctl_fn) (struct dm_target *ti, unsigned int cmd,
unsigned long arg);
typedef int (*dm_prepare_ioctl_fn) (struct dm_target *ti,
struct block_device **bdev, fmode_t *mode);
/*
* These iteration functions are typically used to check (and combine)
@ -156,7 +156,7 @@ struct target_type {
dm_resume_fn resume;
dm_status_fn status;
dm_message_fn message;
dm_ioctl_fn ioctl;
dm_prepare_ioctl_fn prepare_ioctl;
dm_busy_fn busy;
dm_iterate_devices_fn iterate_devices;
dm_io_hints_fn io_hints;