https://github.com/torvalds/linux
Revision acfe0ad74d2e1bfc81d1d7bf5e15b043985d3650 authored by Mikulas Patocka on 14 June 2014, 17:44:31 UTC, committed by Mike Snitzer on 10 July 2014, 20:44:13 UTC
The commit 2c140a246dc ("dm: allow remove to be deferred") introduced a deferred removal feature for the device mapper. When this feature is used (by passing a flag DM_DEFERRED_REMOVE to DM_DEV_REMOVE_CMD ioctl) and the user tries to remove a device that is currently in use, the device will be removed automatically in the future when the last user closes it. Device mapper used the system workqueue to perform deferred removals. However, some targets (dm-raid1, dm-mpath, dm-stripe) flush work items scheduled for the system workqueue from their destructor. If the destructor itself is called from the system workqueue during deferred removal, it introduces a possible deadlock - the workqueue tries to flush itself. Fix this possible deadlock by introducing a new workqueue for deferred removals. We allocate just one workqueue for all dm targets. The ability of dm targets to process IOs isn't dependent on deferred removal of unused targets, so a deadlock due to shared workqueue isn't possible. Also, cleanup local_init() to eliminate potential for returning success on failure. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # 3.13+
1 parent 4c83445
Tip revision: acfe0ad74d2e1bfc81d1d7bf5e15b043985d3650 authored by Mikulas Patocka on 14 June 2014, 17:44:31 UTC
dm: allocate a special workqueue for deferred device removal
dm: allocate a special workqueue for deferred device removal
Tip revision: acfe0ad
File | Mode | Size |
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Documentation | ||
arch | ||
block | ||
crypto | ||
drivers | ||
firmware | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
.gitignore | -rw-r--r-- | 1.1 KB |
.mailmap | -rw-r--r-- | 4.4 KB |
COPYING | -rw-r--r-- | 18.3 KB |
CREDITS | -rw-r--r-- | 93.7 KB |
Kbuild | -rw-r--r-- | 2.5 KB |
Kconfig | -rw-r--r-- | 252 bytes |
MAINTAINERS | -rw-r--r-- | 275.1 KB |
Makefile | -rw-r--r-- | 50.8 KB |
README | -rw-r--r-- | 18.3 KB |
REPORTING-BUGS | -rw-r--r-- | 7.3 KB |
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