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authorLinus Torvalds <torvalds@linux-foundation.org>2022-01-12 21:35:23 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2022-01-12 21:35:23 +0300
commitc9193f48e94deaeff0c9abbc67b9584e8ddc42ed (patch)
treefb50432abb9783a3a78a079e2b142bf3206ea1ca /drivers/block/loop.c
parentd3c810803576d867265277df8e94eee386351c9d (diff)
parentd85bd8233fff000567cda4e108112bcb33478616 (diff)
downloadlinux-c9193f48e94deaeff0c9abbc67b9584e8ddc42ed.tar.xz
Merge tag 'for-5.17/drivers-2022-01-11' of git://git.kernel.dk/linux-block
Pull block driver updates from Jens Axboe: - mtip32xx pci cleanups (Bjorn) - mtip32xx conversion to generic power management (Vaibhav) - rsxx pci powermanagement cleanups (Bjorn) - Remove the rsxx driver. This hardware never saw much adoption, and it's been end of lifed for a while. (Christoph) - MD pull request from Song: - REQ_NOWAIT support (Vishal Verma) - raid6 benchmark optimization (Dirk Müller) - Fix for acct bioset (Xiao Ni) - Clean up max_queued_requests (Mariusz Tkaczyk) - PREEMPT_RT optimization (Davidlohr Bueso) - Use default_groups in kobj_type (Greg Kroah-Hartman) - Use attribute groups in pktcdvd and rnbd (Greg) - NVMe pull request from Christoph: - increment request genctr on completion (Keith Busch, Geliang Tang) - add a 'iopolicy' module parameter (Hannes Reinecke) - print out valid arguments when reading from /dev/nvme-fabrics (Hannes Reinecke) - Use struct_group() in drbd (Kees) - null_blk fixes (Ming) - Get rid of congestion logic in pktcdvd (Neil) - Floppy ejection hang fix (Tasos) - Floppy max user request size fix (Xiongwei) - Loop locking fix (Tetsuo) * tag 'for-5.17/drivers-2022-01-11' of git://git.kernel.dk/linux-block: (32 commits) md: use default_groups in kobj_type md: Move alloc/free acct bioset in to personality lib/raid6: Use strict priority ranking for pq gen() benchmarking lib/raid6: skip benchmark of non-chosen xor_syndrome functions md: fix spelling of "its" md: raid456 add nowait support md: raid10 add nowait support md: raid1 add nowait support md: add support for REQ_NOWAIT md: drop queue limitation for RAID1 and RAID10 md/raid5: play nice with PREEMPT_RT block/rnbd-clt-sysfs: use default_groups in kobj_type pktcdvd: convert to use attribute groups block: null_blk: only set set->nr_maps as 3 if active poll_queues is > 0 nvme: add 'iopolicy' module parameter nvme: drop unused variable ctrl in nvme_setup_cmd nvme: increment request genctr on completion nvme-fabrics: print out valid arguments when reading from /dev/nvme-fabrics block: remove the rsxx driver rsxx: Drop PCI legacy power management ...
Diffstat (limited to 'drivers/block/loop.c')
-rw-r--r--drivers/block/loop.c108
1 files changed, 52 insertions, 56 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index e98ddf08d77d..b1b05c45c07c 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1082,13 +1082,10 @@ out_putf:
return error;
}
-static int __loop_clr_fd(struct loop_device *lo, bool release)
+static void __loop_clr_fd(struct loop_device *lo)
{
- struct file *filp = NULL;
+ struct file *filp;
gfp_t gfp = lo->old_gfp_mask;
- int err = 0;
- bool partscan = false;
- int lo_number;
struct loop_worker *pos, *worker;
/*
@@ -1103,17 +1100,14 @@ static int __loop_clr_fd(struct loop_device *lo, bool release)
* became visible.
*/
+ /*
+ * Since this function is called upon "ioctl(LOOP_CLR_FD)" xor "close()
+ * after ioctl(LOOP_CLR_FD)", it is a sign of something going wrong if
+ * lo->lo_state has changed while waiting for lo->lo_mutex.
+ */
mutex_lock(&lo->lo_mutex);
- if (WARN_ON_ONCE(lo->lo_state != Lo_rundown)) {
- err = -ENXIO;
- goto out_unlock;
- }
-
- filp = lo->lo_backing_file;
- if (filp == NULL) {
- err = -EINVAL;
- goto out_unlock;
- }
+ BUG_ON(lo->lo_state != Lo_rundown);
+ mutex_unlock(&lo->lo_mutex);
if (test_bit(QUEUE_FLAG_WC, &lo->lo_queue->queue_flags))
blk_queue_write_cache(lo->lo_queue, false, false);
@@ -1134,6 +1128,7 @@ static int __loop_clr_fd(struct loop_device *lo, bool release)
del_timer_sync(&lo->timer);
spin_lock_irq(&lo->lo_lock);
+ filp = lo->lo_backing_file;
lo->lo_backing_file = NULL;
spin_unlock_irq(&lo->lo_lock);
@@ -1149,60 +1144,59 @@ static int __loop_clr_fd(struct loop_device *lo, bool release)
/* let user-space know about this change */
kobject_uevent(&disk_to_dev(lo->lo_disk)->kobj, KOBJ_CHANGE);
mapping_set_gfp_mask(filp->f_mapping, gfp);
- /* This is safe: open() is still holding a reference. */
- module_put(THIS_MODULE);
blk_mq_unfreeze_queue(lo->lo_queue);
- partscan = lo->lo_flags & LO_FLAGS_PARTSCAN;
- lo_number = lo->lo_number;
disk_force_media_change(lo->lo_disk, DISK_EVENT_MEDIA_CHANGE);
-out_unlock:
- mutex_unlock(&lo->lo_mutex);
- if (partscan) {
- /*
- * open_mutex has been held already in release path, so don't
- * acquire it if this function is called in such case.
- *
- * If the reread partition isn't from release path, lo_refcnt
- * must be at least one and it can only become zero when the
- * current holder is released.
- */
- if (!release)
- mutex_lock(&lo->lo_disk->open_mutex);
+
+ if (lo->lo_flags & LO_FLAGS_PARTSCAN) {
+ int err;
+
+ mutex_lock(&lo->lo_disk->open_mutex);
err = bdev_disk_changed(lo->lo_disk, false);
- if (!release)
- mutex_unlock(&lo->lo_disk->open_mutex);
+ mutex_unlock(&lo->lo_disk->open_mutex);
if (err)
pr_warn("%s: partition scan of loop%d failed (rc=%d)\n",
- __func__, lo_number, err);
+ __func__, lo->lo_number, err);
/* Device is gone, no point in returning error */
- err = 0;
}
- /*
- * lo->lo_state is set to Lo_unbound here after above partscan has
- * finished.
- *
- * There cannot be anybody else entering __loop_clr_fd() as
- * lo->lo_backing_file is already cleared and Lo_rundown state
- * protects us from all the other places trying to change the 'lo'
- * device.
- */
- mutex_lock(&lo->lo_mutex);
lo->lo_flags = 0;
if (!part_shift)
lo->lo_disk->flags |= GENHD_FL_NO_PART;
+
+ fput(filp);
+}
+
+static void loop_rundown_completed(struct loop_device *lo)
+{
+ mutex_lock(&lo->lo_mutex);
lo->lo_state = Lo_unbound;
mutex_unlock(&lo->lo_mutex);
+ module_put(THIS_MODULE);
+}
- /*
- * Need not hold lo_mutex to fput backing file. Calling fput holding
- * lo_mutex triggers a circular lock dependency possibility warning as
- * fput can take open_mutex which is usually taken before lo_mutex.
- */
- if (filp)
- fput(filp);
- return err;
+static void loop_rundown_workfn(struct work_struct *work)
+{
+ struct loop_device *lo = container_of(work, struct loop_device,
+ rundown_work);
+ struct block_device *bdev = lo->lo_device;
+ struct gendisk *disk = lo->lo_disk;
+
+ __loop_clr_fd(lo);
+ kobject_put(&bdev->bd_device.kobj);
+ module_put(disk->fops->owner);
+ loop_rundown_completed(lo);
+}
+
+static void loop_schedule_rundown(struct loop_device *lo)
+{
+ struct block_device *bdev = lo->lo_device;
+ struct gendisk *disk = lo->lo_disk;
+
+ __module_get(disk->fops->owner);
+ kobject_get(&bdev->bd_device.kobj);
+ INIT_WORK(&lo->rundown_work, loop_rundown_workfn);
+ queue_work(system_long_wq, &lo->rundown_work);
}
static int loop_clr_fd(struct loop_device *lo)
@@ -1234,7 +1228,9 @@ static int loop_clr_fd(struct loop_device *lo)
lo->lo_state = Lo_rundown;
mutex_unlock(&lo->lo_mutex);
- return __loop_clr_fd(lo, false);
+ __loop_clr_fd(lo);
+ loop_rundown_completed(lo);
+ return 0;
}
static int
@@ -1758,7 +1754,7 @@ static void lo_release(struct gendisk *disk, fmode_t mode)
* In autoclear mode, stop the loop thread
* and remove configuration after last close.
*/
- __loop_clr_fd(lo, true);
+ loop_schedule_rundown(lo);
return;
} else if (lo->lo_state == Lo_bound) {
/*