[PATCH v4 5/5] loop: raise media_change event
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STALE1914d
From: Matteo Croce <hidden>
Date: 2021-07-11 17:54:43
Also in:
linux-fsdevel, lkml
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
Revision v4 of 6 in this series.
Revisions (6)
From: Matteo Croce <redacted> Make the loop device raise a DISK_MEDIA_CHANGE event on attach or detach. # udevadm monitor -up |grep -e DISK_MEDIA_CHANGE -e DEVNAME & # losetup -f zero [ 7.454235] loop0: detected capacity change from 0 to 16384 DISK_MEDIA_CHANGE=1 DEVNAME=/dev/loop0 DEVNAME=/dev/loop0 DEVNAME=/dev/loop0 # losetup -f zero [ 10.205245] loop1: detected capacity change from 0 to 16384 DISK_MEDIA_CHANGE=1 DEVNAME=/dev/loop1 DEVNAME=/dev/loop1 DEVNAME=/dev/loop1 # losetup -f zero2 [ 13.532368] loop2: detected capacity change from 0 to 40960 DISK_MEDIA_CHANGE=1 DEVNAME=/dev/loop2 DEVNAME=/dev/loop2 # losetup -D DEVNAME=/dev/loop1 DISK_MEDIA_CHANGE=1 DEVNAME=/dev/loop1 DEVNAME=/dev/loop2 DISK_MEDIA_CHANGE=1 DEVNAME=/dev/loop2 DEVNAME=/dev/loop0 DISK_MEDIA_CHANGE=1 DEVNAME=/dev/loop0 Signed-off-by: Matteo Croce <redacted> --- drivers/block/loop.c | 20 ++++++++++++++++++++ drivers/block/loop.h | 1 + 2 files changed, 21 insertions(+)
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index f37b9e3d833c..c632f9bd33ba 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c@@ -731,6 +731,8 @@ static int loop_change_fd(struct loop_device *lo, struct block_device *bdev, goto out_err; /* and ... switch */ + lo->changed = true; + bdev_check_media_change(bdev); blk_mq_freeze_queue(lo->lo_queue); mapping_set_gfp_mask(old_file->f_mapping, lo->old_gfp_mask); lo->lo_backing_file = file;
@@ -1205,6 +1207,9 @@ static int loop_configure(struct loop_device *lo, fmode_t mode, goto out_unlock; } + lo->changed = true; + bdev_check_media_change(bdev); + set_disk_ro(lo->lo_disk, (lo->lo_flags & LO_FLAGS_READ_ONLY) != 0); INIT_WORK(&lo->rootcg_work, loop_rootcg_workfn);
@@ -1349,6 +1354,8 @@ static int __loop_clr_fd(struct loop_device *lo, bool release) partscan = lo->lo_flags & LO_FLAGS_PARTSCAN && bdev; lo_number = lo->lo_number; + lo->changed = true; + bdev_check_media_change(bdev); out_unlock: mutex_unlock(&lo->lo_mutex); if (partscan) {
@@ -2016,11 +2023,22 @@ static void lo_release(struct gendisk *disk, fmode_t mode) mutex_unlock(&lo->lo_mutex); } +static unsigned int lo_check_events(struct gendisk *disk, unsigned int clearing) +{ + struct loop_device *lo = disk->private_data; + bool changed = lo->changed; + + lo->changed = false; + + return changed ? DISK_EVENT_MEDIA_CHANGE : 0; +} + static const struct block_device_operations lo_fops = { .owner = THIS_MODULE, .open = lo_open, .release = lo_release, .ioctl = lo_ioctl, + .check_events = lo_check_events, #ifdef CONFIG_COMPAT .compat_ioctl = lo_compat_ioctl, #endif
@@ -2325,6 +2343,8 @@ static int loop_add(int i) disk->fops = &lo_fops; disk->private_data = lo; disk->queue = lo->lo_queue; + disk->events = DISK_EVENT_MEDIA_CHANGE; + disk->event_flags = DISK_EVENT_FLAG_UEVENT; sprintf(disk->disk_name, "loop%d", i); add_disk(disk); mutex_unlock(&loop_ctl_mutex);
diff --git a/drivers/block/loop.h b/drivers/block/loop.h
index 1988899db63a..a2fdfd27e6a7 100644
--- a/drivers/block/loop.h
+++ b/drivers/block/loop.h@@ -63,6 +63,7 @@ struct loop_device { struct timer_list timer; bool use_dio; bool sysfs_inited; + bool changed; struct request_queue *lo_queue; struct blk_mq_tag_set tag_set;
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2.31.1