[PATCH 4/6] dm: refactor ioctl handling
From: Christoph Hellwig
Date: Thu Oct 15 2015 - 08:15:13 EST
This moves the call to blkdev_ioctl and the argument checking to core code,
and only leaves a callout to find the block device to operate on it the
targets. This will simplifies the code and will allow 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@xxxxxx>
---
drivers/md/dm-flakey.c | 16 +++++++-------
drivers/md/dm-linear.c | 14 ++++++------
drivers/md/dm-log-writes.c | 13 ++++++-----
drivers/md/dm-mpath.c | 32 +++++++++++----------------
drivers/md/dm-switch.c | 21 ++++++++----------
drivers/md/dm-verity.c | 15 ++++++-------
drivers/md/dm.c | 50 ++++++++++++++++++++++++++++++++-----------
include/linux/device-mapper.h | 6 +++---
8 files changed, 89 insertions(+), 78 deletions(-)
diff --git a/drivers/md/dm-flakey.c b/drivers/md/dm-flakey.c
index 645e8b4..09e2afc 100644
--- a/drivers/md/dm-flakey.c
+++ b/drivers/md/dm-flakey.c
@@ -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,
};
diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c
index 436f5c9..de52864 100644
--- a/drivers/md/dm-linear.c
+++ b/drivers/md/dm-linear.c
@@ -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,
};
diff --git a/drivers/md/dm-log-writes.c b/drivers/md/dm-log-writes.c
index b2912db..624589d 100644
--- a/drivers/md/dm-log-writes.c
+++ b/drivers/md/dm-log-writes.c
@@ -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,
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 5a67671..77066a1 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -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);
@@ -1555,26 +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 (!bdev || ti->len != i_size_read(bdev->bd_inode) >> SECTOR_SHIFT) {
- int err = scsi_verify_blk_ioctl(NULL, cmd);
- if (err)
- r = err;
- }
-
if (r == -ENOTCONN && !fatal_signal_pending(current)) {
spin_lock_irqsave(&m->lock, flags);
if (!m->current_pg) {
@@ -1587,7 +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,
@@ -1703,7 +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,
};
diff --git a/drivers/md/dm-switch.c b/drivers/md/dm-switch.c
index 50fca46..b128575 100644
--- a/drivers/md/dm-switch.c
+++ b/drivers/md/dm-switch.c
@@ -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,
};
diff --git a/drivers/md/dm-verity.c b/drivers/md/dm-verity.c
index edc624b..ccf4188 100644
--- a/drivers/md/dm-verity.c
+++ b/drivers/md/dm-verity.c
@@ -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,
};
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 6264781..017c712 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -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 +582,41 @@ retry:
goto out;
}
- r = tgt->type->ioctl(tgt, cmd, arg);
+ r = (*tgt)->type->prepare_ioctl(*tgt, bdev, mode);
+ if (r < 0)
+ goto out;
-out:
- dm_put_live_table(md, srcu_idx);
+ return r;
+out:
+ 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) {
+ 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;
}
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 76d23fa..ec1c61c 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -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;
--
1.9.1
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