This is the 6th series of driver conversions for add_disk() error
handling. This set alog with the other 7th set of driver conversions
can be found on my 20210927-for-axboe-add-disk-error-handling branch[0].
It would seem the floppy world is not so exciting and so
the only change does in this v2 iteration is rebasing the patches onto
linux-next tag 20210927.
[0] https://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux-next.git/log/?h=20210927-for-axboe-add-disk-error-handling
Luis Chamberlain (14):
block/swim3: add error handling support for add_disk()
floppy: fix add_disk() assumption on exit due to new developments
floppy: use blk_cleanup_disk()
floppy: fix calling platform_device_unregister() on invalid drives
floppy: add error handling support for add_disk()
amiflop: add error handling support for add_disk()
swim: simplify using blk_cleanup_disk() on swim_remove()
swim: add helper for disk cleanup
swim: add a floppy registration bool which triggers del_gendisk()
swim: add error handling support for add_disk()
block/ataflop: use the blk_cleanup_disk() helper
block/ataflop: add registration bool before calling del_gendisk()
block/ataflop: provide a helper for cleanup up an atari disk
block/ataflop: add error handling support for add_disk()
drivers/block/amiflop.c | 7 ++++--
drivers/block/ataflop.c | 47 +++++++++++++++++++++++++----------------
drivers/block/floppy.c | 34 +++++++++++------------------
drivers/block/swim.c | 35 ++++++++++++++++++------------
drivers/block/swim3.c | 4 +++-
5 files changed, 71 insertions(+), 56 deletions(-)
--
2.30.2
We never checked for errors on add_disk() as this function
returned void. Now that this is fixed, use the shiny new
error handling.
Signed-off-by: Luis Chamberlain <[email protected]>
---
drivers/block/ataflop.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/block/ataflop.c b/drivers/block/ataflop.c
index e9d874f51597..5dc9b3d32415 100644
--- a/drivers/block/ataflop.c
+++ b/drivers/block/ataflop.c
@@ -2081,7 +2081,9 @@ static int __init atari_floppy_init (void)
for (i = 0; i < FD_MAX_UNITS; i++) {
unit[i].track = -1;
unit[i].flags = 0;
- add_disk(unit[i].disk[0]);
+ ret = add_disk(unit[i].disk[0]);
+ if (ret)
+ goto err_out_dma;
unit[i].registered[0] = true;
}
@@ -2092,6 +2094,8 @@ static int __init atari_floppy_init (void)
return 0;
+err_out_dma:
+ atari_stram_free(DMABuffer);
err:
while (--i >= 0)
atari_cleanup_floppy_disk(&unit[i]);
--
2.30.2
platform_device_unregister() should only be called when
a respective platform_device_register() is called. However
the floppy driver currently allows failures when registring
a drive and a bail out could easily cause an invalid call
to platform_device_unregister() where it was not intended.
Fix this by adding a bool to keep track of when the platform
device was registered for a drive.
This does not fix any known panic / bug. This issue was found
through code inspection while preparing the driver to use the
up and coming support for device_add_disk() error handling.
From what I can tell from code inspection, chances of this
ever happening should be insanely small, perhaps OOM.
Signed-off-by: Luis Chamberlain <[email protected]>
---
drivers/block/floppy.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index 9538146e520e..3592a6277d0b 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -4478,6 +4478,7 @@ static const struct blk_mq_ops floppy_mq_ops = {
};
static struct platform_device floppy_device[N_DRIVE];
+static bool registered[N_DRIVE];
static bool floppy_available(int drive)
{
@@ -4693,6 +4694,8 @@ static int __init do_floppy_init(void)
if (err)
goto out_remove_drives;
+ registered[drive] = true;
+
device_add_disk(&floppy_device[drive].dev, disks[drive][0],
NULL);
}
@@ -4703,7 +4706,8 @@ static int __init do_floppy_init(void)
while (drive--) {
if (floppy_available(drive)) {
del_gendisk(disks[drive][0]);
- platform_device_unregister(&floppy_device[drive]);
+ if (registered[drive])
+ platform_device_unregister(&floppy_device[drive]);
}
}
out_release_dma:
@@ -4946,7 +4950,8 @@ static void __exit floppy_module_exit(void)
if (disks[drive][i])
del_gendisk(disks[drive][i]);
}
- platform_device_unregister(&floppy_device[drive]);
+ if (registered[drive])
+ platform_device_unregister(&floppy_device[drive]);
}
for (i = 0; i < ARRAY_SIZE(floppy_type); i++) {
if (disks[drive][i])
--
2.30.2
We never checked for errors on add_disk() as this function
returned void. Now that this is fixed, use the shiny new
error handling.
Signed-off-by: Luis Chamberlain <[email protected]>
---
drivers/block/floppy.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index 3592a6277d0b..0434f28742e7 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -4696,8 +4696,10 @@ static int __init do_floppy_init(void)
registered[drive] = true;
- device_add_disk(&floppy_device[drive].dev, disks[drive][0],
- NULL);
+ err = device_add_disk(&floppy_device[drive].dev,
+ disks[drive][0], NULL);
+ if (err)
+ goto out_remove_drives;
}
return 0;
--
2.30.2
We never checked for errors on add_disk() as this function
returned void. Now that this is fixed, use the shiny new
error handling. The caller for fd_alloc_disk() deals with
the rest of the cleanup like the tag.
Signed-off-by: Luis Chamberlain <[email protected]>
---
drivers/block/amiflop.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/block/amiflop.c b/drivers/block/amiflop.c
index 8b1714021498..7da6a7532cde 100644
--- a/drivers/block/amiflop.c
+++ b/drivers/block/amiflop.c
@@ -1780,6 +1780,7 @@ static const struct blk_mq_ops amiflop_mq_ops = {
static int fd_alloc_disk(int drive, int system)
{
struct gendisk *disk;
+ int err;
disk = blk_mq_alloc_disk(&unit[drive].tag_set, NULL);
if (IS_ERR(disk))
@@ -1798,8 +1799,10 @@ static int fd_alloc_disk(int drive, int system)
set_capacity(disk, 880 * 2);
unit[drive].gendisk[system] = disk;
- add_disk(disk);
- return 0;
+ err = add_disk(disk);
+ if (err)
+ blk_cleanup_disk(disk);
+ return err;
}
static int fd_alloc_drive(int drive)
--
2.30.2
We never checked for errors on add_disk() as this function
returned void. Now that this is fixed, use the shiny new
error handling.
Since we have a caller to do our unwinding for the disk,
and this is already dealt with safely we can re-use our
existing error path goto label which already deals with
the cleanup.
Signed-off-by: Luis Chamberlain <[email protected]>
---
drivers/block/swim.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/block/swim.c b/drivers/block/swim.c
index b3ee3dad5a8c..6f02941a3263 100644
--- a/drivers/block/swim.c
+++ b/drivers/block/swim.c
@@ -842,7 +842,9 @@ static int swim_floppy_init(struct swim_priv *swd)
swd->unit[drive].disk->events = DISK_EVENT_MEDIA_CHANGE;
swd->unit[drive].disk->private_data = &swd->unit[drive];
set_capacity(swd->unit[drive].disk, 2880);
- add_disk(swd->unit[drive].disk);
+ err = add_disk(swd->unit[drive].disk);
+ if (err)
+ goto exit_put_disks;
swd->unit[drive].registered = true;
}
--
2.30.2
After the patch titled "floppy: use blk_mq_alloc_disk and
blk_cleanup_disk" the floppy driver was modified to allocate
the blk_mq_alloc_disk() which allocates the disk with the
queue. This is further clarified later with the patch titled
"block: remove alloc_disk and alloc_disk_node". This clarifies
that:
Most drivers should use and have been converted to use
blk_alloc_disk and blk_mq_alloc_disk. Only the scsi
ULPs and dasd still allocate a disk separately from the
request_queue so don't bother with convenience macros for
something that should not see significant new users and
remove these wrappers.
And then we have the patch titled, "block: hold a request_queue
reference for the lifetime of struct gendisk" which ensures
that a queue is *always* present for sure during the entire
lifetime of a disk.
In the floppy driver's case then the disk always comes with the
queue. So even if even if the queue was cleaned up on exit, putting
the disk *is* still required, and likewise, blk_cleanup_queue() on
a null queue should not happen now as disk->queue is valid from
disk allocation time on.
Automatic backport code scrapers should hopefully not cherry pick
this patch as a stable fix candidate without full due dilligence to
ensure all the work done on the block layer to make this happen is
merged first.
Signed-off-by: Luis Chamberlain <[email protected]>
---
drivers/block/floppy.c | 13 -------------
1 file changed, 13 deletions(-)
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index fef79ea52e3e..3e6390fd5f2b 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -4953,19 +4953,6 @@ static void __exit floppy_module_exit(void)
blk_cleanup_queue(disks[drive][i]->queue);
}
blk_mq_free_tag_set(&tag_sets[drive]);
-
- /*
- * These disks have not called add_disk(). Don't put down
- * queue reference in put_disk().
- */
- if (!(allowed_drive_mask & (1 << drive)) ||
- fdc_state[FDC(drive)].version == FDC_NONE) {
- for (i = 0; i < ARRAY_SIZE(floppy_type); i++) {
- if (disks[drive][i])
- disks[drive][i]->queue = NULL;
- }
- }
-
for (i = 0; i < ARRAY_SIZE(floppy_type); i++) {
if (disks[drive][i])
put_disk(disks[drive][i]);
--
2.30.2
We can simplify swim_remove() by using one call instead of two,
just as other drivers do. Use that pattern.
Signed-off-by: Luis Chamberlain <[email protected]>
---
drivers/block/swim.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/block/swim.c b/drivers/block/swim.c
index 7ccc8d2a41bc..f085ea982bb7 100644
--- a/drivers/block/swim.c
+++ b/drivers/block/swim.c
@@ -911,9 +911,8 @@ static int swim_remove(struct platform_device *dev)
for (drive = 0; drive < swd->floppy_count; drive++) {
del_gendisk(swd->unit[drive].disk);
- blk_cleanup_queue(swd->unit[drive].disk->queue);
+ blk_cleanup_disk(swd->unit[drive].disk);
blk_mq_free_tag_set(&swd->unit[drive].tag_set);
- put_disk(swd->unit[drive].disk);
}
unregister_blkdev(FLOPPY_MAJOR, "fd");
--
2.30.2
Use the helper to replace two lines with one.
Signed-off-by: Luis Chamberlain <[email protected]>
---
drivers/block/ataflop.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/drivers/block/ataflop.c b/drivers/block/ataflop.c
index a093644ac39f..6a865d42b1fd 100644
--- a/drivers/block/ataflop.c
+++ b/drivers/block/ataflop.c
@@ -2076,8 +2076,7 @@ static int __init atari_floppy_init (void)
err:
while (--i >= 0) {
- blk_cleanup_queue(unit[i].disk[0]->queue);
- put_disk(unit[i].disk[0]);
+ blk_cleanup_disk(unit[i].disk[0]);
blk_mq_free_tag_set(&unit[i].tag_set);
}
@@ -2135,8 +2134,7 @@ static void __exit atari_floppy_exit(void)
if (!unit[i].disk[type])
continue;
del_gendisk(unit[i].disk[type]);
- blk_cleanup_queue(unit[i].disk[type]->queue);
- put_disk(unit[i].disk[type]);
+ blk_cleanup_disk(unit[i].disk[type]);
}
blk_mq_free_tag_set(&unit[i].tag_set);
}
--
2.30.2
The ataflop assumes del_gendisk() is safe to call, this is only
true because add_disk() does not return a failure, but that will
change soon. And so, before we get to adding error handling for
that case, let's make sure we keep track of which disks actually
get registered. Then we use this to only call del_gendisk for them.
Signed-off-by: Luis Chamberlain <[email protected]>
---
drivers/block/ataflop.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/block/ataflop.c b/drivers/block/ataflop.c
index 6a865d42b1fd..97f1c19f9c02 100644
--- a/drivers/block/ataflop.c
+++ b/drivers/block/ataflop.c
@@ -298,6 +298,7 @@ static struct atari_floppy_struct {
disk change detection) */
int flags; /* flags */
struct gendisk *disk[NUM_DISK_MINORS];
+ bool registered[NUM_DISK_MINORS];
int ref;
int type;
struct blk_mq_tag_set tag_set;
@@ -2000,8 +2001,10 @@ static void ataflop_probe(dev_t dev)
return;
mutex_lock(&ataflop_probe_lock);
if (!unit[drive].disk[type]) {
- if (ataflop_alloc_disk(drive, type) == 0)
+ if (ataflop_alloc_disk(drive, type) == 0) {
add_disk(unit[drive].disk[type]);
+ unit[drive].registered[type] = true;
+ }
}
mutex_unlock(&ataflop_probe_lock);
}
@@ -2065,6 +2068,7 @@ static int __init atari_floppy_init (void)
unit[i].track = -1;
unit[i].flags = 0;
add_disk(unit[i].disk[0]);
+ unit[i].registered[0] = true;
}
printk(KERN_INFO "Atari floppy driver: max. %cD, %strack buffering\n",
@@ -2133,7 +2137,8 @@ static void __exit atari_floppy_exit(void)
for (type = 0; type < NUM_DISK_MINORS; type++) {
if (!unit[i].disk[type])
continue;
- del_gendisk(unit[i].disk[type]);
+ if (unit[i].registered[type])
+ del_gendisk(unit[i].disk[type]);
blk_cleanup_disk(unit[i].disk[type]);
}
blk_mq_free_tag_set(&unit[i].tag_set);
--
2.30.2
Instead of calling del_gendisk() on exit alone, let's add
a registration bool to the floppy disk state, this way this can
be done on the shared caller, swim_cleanup_floppy_disk().
This will be more useful in subsequent patches. Right now, this
just shuffles functionality out to a helper in a safe way.
Signed-off-by: Luis Chamberlain <[email protected]>
---
drivers/block/swim.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/block/swim.c b/drivers/block/swim.c
index 3deb9d9a59c0..b3ee3dad5a8c 100644
--- a/drivers/block/swim.c
+++ b/drivers/block/swim.c
@@ -184,6 +184,7 @@ struct floppy_state {
int track;
int ref_count;
+ bool registered;
struct gendisk *disk;
struct blk_mq_tag_set tag_set;
@@ -778,6 +779,9 @@ static void swim_cleanup_floppy_disk(struct floppy_state *fs)
if (!disk)
return;
+ if (fs->registered)
+ del_gendisk(fs->disk);
+
blk_cleanup_disk(disk);
blk_mq_free_tag_set(&fs->tag_set);
}
@@ -839,6 +843,7 @@ static int swim_floppy_init(struct swim_priv *swd)
swd->unit[drive].disk->private_data = &swd->unit[drive];
set_capacity(swd->unit[drive].disk, 2880);
add_disk(swd->unit[drive].disk);
+ swd->unit[drive].registered = true;
}
return 0;
@@ -915,10 +920,8 @@ static int swim_remove(struct platform_device *dev)
int drive;
struct resource *res;
- for (drive = 0; drive < swd->floppy_count; drive++) {
- del_gendisk(swd->unit[drive].disk);
+ for (drive = 0; drive < swd->floppy_count; drive++)
swim_cleanup_floppy_disk(&swd->unit[drive]);
- }
unregister_blkdev(FLOPPY_MAJOR, "fd");
--
2.30.2
Instead of using two separate code paths for cleaning up an atari disk,
use one. We take the more careful approach to check for *all* disk
types, as is done on exit. The init path didn't have that check as
the alternative disk types are only probed for later, they are not
initialized by default.
Yes, there is a shared tag for all disks.
Signed-off-by: Luis Chamberlain <[email protected]>
---
drivers/block/ataflop.c | 34 +++++++++++++++++++---------------
1 file changed, 19 insertions(+), 15 deletions(-)
diff --git a/drivers/block/ataflop.c b/drivers/block/ataflop.c
index 97f1c19f9c02..e9d874f51597 100644
--- a/drivers/block/ataflop.c
+++ b/drivers/block/ataflop.c
@@ -2009,6 +2009,20 @@ static void ataflop_probe(dev_t dev)
mutex_unlock(&ataflop_probe_lock);
}
+static void atari_cleanup_floppy_disk(struct atari_floppy_struct *fs)
+{
+ int type;
+
+ for (type = 0; type < NUM_DISK_MINORS; type++) {
+ if (!fs->disk[type])
+ continue;
+ if (fs->registered[type])
+ del_gendisk(fs->disk[type]);
+ blk_cleanup_disk(fs->disk[type]);
+ }
+ blk_mq_free_tag_set(&fs->tag_set);
+}
+
static int __init atari_floppy_init (void)
{
int i;
@@ -2079,10 +2093,8 @@ static int __init atari_floppy_init (void)
return 0;
err:
- while (--i >= 0) {
- blk_cleanup_disk(unit[i].disk[0]);
- blk_mq_free_tag_set(&unit[i].tag_set);
- }
+ while (--i >= 0)
+ atari_cleanup_floppy_disk(&unit[i]);
unregister_blkdev(FLOPPY_MAJOR, "fd");
out_unlock:
@@ -2131,18 +2143,10 @@ __setup("floppy=", atari_floppy_setup);
static void __exit atari_floppy_exit(void)
{
- int i, type;
+ int i;
- for (i = 0; i < FD_MAX_UNITS; i++) {
- for (type = 0; type < NUM_DISK_MINORS; type++) {
- if (!unit[i].disk[type])
- continue;
- if (unit[i].registered[type])
- del_gendisk(unit[i].disk[type]);
- blk_cleanup_disk(unit[i].disk[type]);
- }
- blk_mq_free_tag_set(&unit[i].tag_set);
- }
+ for (i = 0; i < FD_MAX_UNITS; i++)
+ atari_cleanup_floppy_disk(&unit[i]);
unregister_blkdev(FLOPPY_MAJOR, "fd");
del_timer_sync(&fd_timer);
--
2.30.2
Disk cleanup can be shared between exit and bringup. Use a
helper to do the work required. The only functional change at
this point is we're being overly paraoid on exit to check for
a null disk as well now, and this should be safe.
We'll later expand on this, this change just makes subsequent
changes easier to read.
Signed-off-by: Luis Chamberlain <[email protected]>
---
drivers/block/swim.c | 21 +++++++++++++--------
1 file changed, 13 insertions(+), 8 deletions(-)
diff --git a/drivers/block/swim.c b/drivers/block/swim.c
index f085ea982bb7..3deb9d9a59c0 100644
--- a/drivers/block/swim.c
+++ b/drivers/block/swim.c
@@ -771,6 +771,17 @@ static const struct blk_mq_ops swim_mq_ops = {
.queue_rq = swim_queue_rq,
};
+static void swim_cleanup_floppy_disk(struct floppy_state *fs)
+{
+ struct gendisk *disk = fs->disk;
+
+ if (!disk)
+ return;
+
+ blk_cleanup_disk(disk);
+ blk_mq_free_tag_set(&fs->tag_set);
+}
+
static int swim_floppy_init(struct swim_priv *swd)
{
int err;
@@ -835,12 +846,7 @@ static int swim_floppy_init(struct swim_priv *swd)
exit_put_disks:
unregister_blkdev(FLOPPY_MAJOR, "fd");
do {
- struct gendisk *disk = swd->unit[drive].disk;
-
- if (!disk)
- continue;
- blk_cleanup_disk(disk);
- blk_mq_free_tag_set(&swd->unit[drive].tag_set);
+ swim_cleanup_floppy_disk(&swd->unit[drive]);
} while (drive--);
return err;
}
@@ -911,8 +917,7 @@ static int swim_remove(struct platform_device *dev)
for (drive = 0; drive < swd->floppy_count; drive++) {
del_gendisk(swd->unit[drive].disk);
- blk_cleanup_disk(swd->unit[drive].disk);
- blk_mq_free_tag_set(&swd->unit[drive].tag_set);
+ swim_cleanup_floppy_disk(&swd->unit[drive]);
}
unregister_blkdev(FLOPPY_MAJOR, "fd");
--
2.30.2
On 9/27/21 4:02 PM, Luis Chamberlain wrote:
> This is the 6th series of driver conversions for add_disk() error
> handling. This set alog with the other 7th set of driver conversions
> can be found on my 20210927-for-axboe-add-disk-error-handling branch[0].
>
> It would seem the floppy world is not so exciting and so
> the only change does in this v2 iteration is rebasing the patches onto
> linux-next tag 20210927.
Applied, thanks.
--
Jens Axboe