Currently, when a gfs2 filesystem is withdrawn, an "offline" uevent is
triggered that invokes gfs2-util's gfs2_withdraw_helper script. The
purpose of this script is to deactivate the filesystem's block device so
that it can be withdrawn immediately, even before all the filesystem's
caches have been discarded. The script provided by gfs2-utils never did
anything useful, and there was no way for it to report back its status
to the kernel.
To fix that, extend the gfs2_withdraw_helper mechanism so that the
script can report one of the following results by writing the
corresponding value into "/sys$DEVPATH/lock_module/withdraw":
0 - The shared block device has been marked inactive. Future write
operations will fail.
1 - The shared block device may still be active and carry out
write operations.
If the "offline" uevent isn't reacted upon within the timeout configured
in /sys$DEVPATH/tune/withdraw_helper_timeout (default 5 seconds), the
event handler is assumed to have failed.
In addition, add an additional "errors=deactivate" mount option.
With these changes, if fatal errors are detected on a gfs2 filesystem
and the filesystem is mounted with the "errors=panic" option, the kernel
will panic immediately. Otherwise, an attempt will be made to
deactivate the underlying block device. If successful, the kernel will
release all cluster-wide locks immediately so that the rest of the
cluster can continue. If unsuccessful, the kernel will either panic
("errors=deactivate"), or it will purge all filesystem I/O before
releasing all cluster-wide locks ("errors=withdraw").
Note that the gfs2_withdraw_helper script still needs to be fixed to
take advantage of these improvements. It could be changed to use a
mechanism like LVM Persistent Reservations. "dmsetup suspend" is not a
suitable mechanism as it infinitely postpones I/O operations, which may
prevent withdraw from completing.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
The current withdraw code duplicates the journal recovery code gfs2
already has for dealing with node failures, and it does so poorly. That
code was added because when releasing a lockspace, we didn't have a way
to indicate that the lockspace needs recovery. We now do have this
feature, so the current withdraw code can be removed almost entirely.
This is one of several steps towards that.
Reverts parts of commit 601ef0d52e ("gfs2: Force withdraw to replay
journals and wait for it to finish").
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
The current withdraw code duplicates the journal recovery code gfs2
already has for dealing with node failures, and it does so poorly. That
code was added because when releasing a lockspace, we didn't have a way
to indicate that the lockspace needs recovery. We now do have this
feature, so the current withdraw code can be removed almost entirely.
This is one of several steps towards that.
Reverts parts of commit 601ef0d52e ("gfs2: Force withdraw to replay
journals and wait for it to finish").
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
The current withdraw code duplicates the journal recovery code gfs2
already has for dealing with node failures, and it does so poorly. That
code was added because when releasing a lockspace, we didn't have a way
to indicate that the lockspace needs recovery. We now do have this
feature, so the current withdraw code can be removed almost entirely.
This is one of several steps towards that.
The withdrawing node has no role in recovering from the withdraw
anymore, so it also no longer needs to read metadata blocks after a
withdraw.
We now only need to set a single bit in gfs2_withdraw(), so switch from
try_cmpxchg() to test_and_set_bit().
Reverts commit 8cc67f704f ("gfs2: don't stop reads while withdraw in
progress").
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
With delayed withdraws and the SDF_WITHDRAWING flag gone, we can now
rename gfs2_withdrawing_or_withdrawn() back to gfs2_withdrawn().
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Now that gfs2_withdraw() is asynchronous, is can be called in any
context and there is no more need for gfs2_withdraw_delayed() or for
turning delayed withdraws into actual withdraws. Remove the
now-obsolete code.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Documentation/filesystems/sysfs.rst mentions that show() should only
use sysfs_emit() or sysfs_emit_at() when formatting values returned
to user space. This patch updates the GFS2 sysfs interface accordingly.
It replaces uses of sprintf() and snprintf() in all *_show() functions
with sysfs_emit() to align with current kernel sysfs API best practices.
It also updates the TUNE_ATTR_2 macro to use sysfs_emit() instead of
snprintf().
Signed-off-by: Utkarsh Singh <utkarsh.singh.em@gmail.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
When gfs2_sys_fs_add() fails, it sets sb->s_fs_info to NULL on its error
path (see commit 0d515210b6 ("GFS2: Add kobject release method")).
The intention seems to be to prevent dereferencing sb->s_fs_info once
the object pointed to has been deallocated, but that would be better
achieved by setting the pointer to NULL in free_sbd().
As a consequence, when the call to gfs2_sys_fs_add() fails in
gfs2_fill_super(), sdp = GFS2_SB(inode) will evaluate to NULL in iput()
-> gfs2_drop_inode(), and accessing sdp->sd_flags will be a NULL pointer
dereference.
Fix that by only setting sb->s_fs_info to NULL when actually freeing the
object pointed to in free_sbd().
Fixes: ae9f3bd825 ("gfs2: replace sd_aspace with sd_inode")
Reported-by: syzbot+b12826218502df019f9d@syzkaller.appspotmail.com
Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Allow the power subsystem to support filesystem freeze for
suspend and hibernate.
For some kernel subsystems it is paramount that they are guaranteed that
they are the owner of the freeze to avoid any risk of deadlocks. This is
the case for the power subsystem. Enable it to recognize whether it did
actually freeze the filesystem.
If userspace has 10 filesystems and suspend/hibernate manges to freeze 5
and then fails on the 6th for whatever odd reason (current or future)
then power needs to undo the freeze of the first 5 filesystems. It can't
just walk the list again because while it's unlikely that a new
filesystem got added in the meantime it still cannot tell which
filesystems the power subsystem actually managed to get a freeze
reference count on that needs to be dropped during thaw.
There's various ways out of this ugliness. For example, record the
filesystems the power subsystem managed to freeze on a temporary list in
the callbacks and then walk that list backwards during thaw to undo the
freezing or make sure that the power subsystem just actually exclusively
freezes things it can freeze and marking such filesystems as being owned
by power for the duration of the suspend or resume cycle. I opted for
the latter as that seemed the clean thing to do even if it means more
code changes.
If hibernation races with filesystem freezing (e.g. DM reconfiguration),
then hibernation need not freeze a filesystem because it's already
frozen but userspace may thaw the filesystem before hibernation actually
happens.
If the race happens the other way around, DM reconfiguration may
unexpectedly fail with EBUSY.
So allow FREEZE_EXCL to nest with other holders. An exclusive freezer
cannot be undone by any of the other concurrent freezers.
Link: https://lore.kernel.org/r/20250329-work-freeze-v2-6-a47af37ecc3d@kernel.org
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
When calling gfs2_glock_get(), consistently pass the CREATE or NO_CREATE
flag for the create argument. This is the only place that passes 0
instead.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Follow up to commit e7beb8b6de ("gfs2: Rename SDF_DEACTIVATING to
SDF_KILL") and change the description of the SDF_KILL flag from
"Deactivating" to "Killing".
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
This function checks whether the filesystem has been been marked to be
withdrawn eventually or has been withdrawn already. Rename this
function to avoid confusing code like checking for gfs2_withdrawing()
when gfs2_withdrawn() has already returned true.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Pull gfs2 updates from Andreas Gruenbacher:
- Fix a glock state (non-)transition bug when a dlm request times out
and is canceled, and we have locking requests that can now be granted
immediately
- Various fixes and cleanups in how the logd and quotad daemons are
woken up and terminated
- Fix several bugs in the quota data reference counting and shrinking.
Free quota data objects synchronously in put_super() instead of
letting call_rcu() run wild
- Make sure not to deallocate quota data during a withdraw; rather,
defer quota data deallocation to put_super(). Withdraws can happen in
contexts in which callers on the stack are holding quota data
references
- Many minor quota fixes and cleanups by Bob
- Update the the mailing list address for gfs2 and dlm. (It's the same
list for both and we are moving it to gfs2@lists.linux.dev)
- Various other minor cleanups
* tag 'gfs2-v6.5-rc5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2: (51 commits)
MAINTAINERS: Update dlm mailing list
MAINTAINERS: Update gfs2 mailing list
gfs2: change qd_slot_count to qd_slot_ref
gfs2: check for no eligible quota changes
gfs2: Remove useless assignment
gfs2: simplify slot_get
gfs2: Simplify qd2offset
gfs2: introduce qd_bh_get_or_undo
gfs2: Remove quota allocation info from quota file
gfs2: use constant for array size
gfs2: Set qd_sync_gen in do_sync
gfs2: Remove useless err set
gfs2: Small gfs2_quota_lock cleanup
gfs2: move qdsb_put and reduce redundancy
gfs2: improvements to sysfs status
gfs2: Don't try to sync non-changes
gfs2: Simplify function need_sync
gfs2: remove unneeded pg_oflow variable
gfs2: remove unneeded variable done
gfs2: pass sdp to gfs2_write_buf_to_page
...
This patch adds some new fields to the gfs2 status file in sysfs to aid
in debugging.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Rename the SDF_DEACTIVATING flag to SDF_KILL to make it more obvious
that this relates to the kill_sb filesystem operation.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Userspace can freeze a filesystem using the FIFREEZE ioctl or by
suspending the block device; this state persists until userspace thaws
the filesystem with the FITHAW ioctl or resuming the block device.
Since commit 18e9e5104f ("Introduce freeze_super and thaw_super for
the fsfreeze ioctl") we only allow the first freeze command to succeed.
The kernel may decide that it is necessary to freeze a filesystem for
its own internal purposes, such as suspends in progress, filesystem fsck
activities, or quiescing a device prior to removal. Userspace thaw
commands must never break a kernel freeze, and kernel thaw commands
shouldn't undo userspace's freeze command.
Introduce a couple of freeze holder flags and wire it into the
sb_writers state. One kernel and one userspace freeze are allowed to
coexist at the same time; the filesystem will not thaw until both are
lifted.
I wonder if the f2fs/gfs2 code should be using a kernel freeze here, but
for now we'll use FREEZE_HOLDER_USERSPACE to preserve existing
behaviors.
Cc: mcgrof@kernel.org
Cc: jack@suse.cz
Cc: hch@infradead.org
Cc: ruansy.fnst@fujitsu.com
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Replace sd_freeze_state with a new SDF_FROZEN flag.
There no longer is a need for indicating that a freeze is in progress
(SDF_STARTING_FREEZE); we are now protecting the critical sections with
the sd_freeze_mutex.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Rename the SDF_FS_FROZEN flag to SDF_FREEZE_INITIATOR to indicate more
clearly that the node that has this flag set is the initiator of the
freeze.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com
Pull driver core updates from Greg KH:
"Here is the large set of driver core changes for 6.3-rc1.
There's a lot of changes this development cycle, most of the work
falls into two different categories:
- fw_devlink fixes and updates. This has gone through numerous review
cycles and lots of review and testing by lots of different devices.
Hopefully all should be good now, and Saravana will be keeping a
watch for any potential regression on odd embedded systems.
- driver core changes to work to make struct bus_type able to be
moved into read-only memory (i.e. const) The recent work with Rust
has pointed out a number of areas in the driver core where we are
passing around and working with structures that really do not have
to be dynamic at all, and they should be able to be read-only
making things safer overall. This is the contuation of that work
(started last release with kobject changes) in moving struct
bus_type to be constant. We didn't quite make it for this release,
but the remaining patches will be finished up for the release after
this one, but the groundwork has been laid for this effort.
Other than that we have in here:
- debugfs memory leak fixes in some subsystems
- error path cleanups and fixes for some never-able-to-be-hit
codepaths.
- cacheinfo rework and fixes
- Other tiny fixes, full details are in the shortlog
All of these have been in linux-next for a while with no reported
problems"
[ Geert Uytterhoeven points out that that last sentence isn't true, and
that there's a pending report that has a fix that is queued up - Linus ]
* tag 'driver-core-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (124 commits)
debugfs: drop inline constant formatting for ERR_PTR(-ERROR)
OPP: fix error checking in opp_migrate_dentry()
debugfs: update comment of debugfs_rename()
i3c: fix device.h kernel-doc warnings
dma-mapping: no need to pass a bus_type into get_arch_dma_ops()
driver core: class: move EXPORT_SYMBOL_GPL() lines to the correct place
Revert "driver core: add error handling for devtmpfs_create_node()"
Revert "devtmpfs: add debug info to handle()"
Revert "devtmpfs: remove return value of devtmpfs_delete_node()"
driver core: cpu: don't hand-override the uevent bus_type callback.
devtmpfs: remove return value of devtmpfs_delete_node()
devtmpfs: add debug info to handle()
driver core: add error handling for devtmpfs_create_node()
driver core: bus: update my copyright notice
driver core: bus: add bus_get_dev_root() function
driver core: bus: constify bus_unregister()
driver core: bus: constify some internal functions
driver core: bus: constify bus_get_kset()
driver core: bus: constify bus_register/unregister_notifier()
driver core: remove private pointer from struct bus_type
...
Add a new SDF_DEACTIVATING super block flag that is set when the
filesystem has started to deactivate. This will be used in the next
patch to stop and drain the delete work during unmount.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
This patch adds a new file: /sys/fs/gfs2/*/status which will report
the status of the file system. Catting this file dumps the current
status of the file system according to various superblock variables.
For example:
Journal Checked: 1
Journal Live: 1
Journal ID: 0
Spectator: 0
Withdrawn: 0
No barriers: 0
No recovery: 0
Demote: 0
No Journal ID: 1
Mounted RO: 0
RO Recovery: 0
Skip DLM Unlock: 0
Force AIL Flush: 0
FS Frozen: 0
Withdrawing: 0
Withdraw In Prog: 0
Remote Withdraw: 0
Withdraw Recovery: 0
sd_log_error: 0
sd_log_flush_lock: 0
sd_log_num_revoke: 0
sd_log_in_flight: 0
sd_log_blks_needed: 0
sd_log_blks_free: 32768
sd_log_flush_head: 0
sd_log_flush_tail: 5384
sd_log_blks_reserved: 0
sd_log_revokes_available: 503
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
syzkaller found the following splat with CONFIG_DEBUG_KOBJECT_RELEASE=y:
Read of size 1 at addr ffff000028e896b8 by task kworker/1:2/228
CPU: 1 PID: 228 Comm: kworker/1:2 Tainted: G S 5.9.0-rc8+ #101
Hardware name: linux,dummy-virt (DT)
Workqueue: events kobject_delayed_cleanup
Call trace:
dump_backtrace+0x0/0x4d8
show_stack+0x34/0x48
dump_stack+0x174/0x1f8
print_address_description.constprop.0+0x5c/0x550
kasan_report+0x13c/0x1c0
__asan_report_load1_noabort+0x34/0x60
memcmp+0xd0/0xd8
gfs2_uevent+0xc4/0x188
kobject_uevent_env+0x54c/0x1240
kobject_uevent+0x2c/0x40
__kobject_del+0x190/0x1d8
kobject_delayed_cleanup+0x2bc/0x3b8
process_one_work+0x96c/0x18c0
worker_thread+0x3f0/0xc30
kthread+0x390/0x498
ret_from_fork+0x10/0x18
Allocated by task 1110:
kasan_save_stack+0x28/0x58
__kasan_kmalloc.isra.0+0xc8/0xe8
kasan_kmalloc+0x10/0x20
kmem_cache_alloc_trace+0x1d8/0x2f0
alloc_super+0x64/0x8c0
sget_fc+0x110/0x620
get_tree_bdev+0x190/0x648
gfs2_get_tree+0x50/0x228
vfs_get_tree+0x84/0x2e8
path_mount+0x1134/0x1da8
do_mount+0x124/0x138
__arm64_sys_mount+0x164/0x238
el0_svc_common.constprop.0+0x15c/0x598
do_el0_svc+0x60/0x150
el0_svc+0x34/0xb0
el0_sync_handler+0xc8/0x5b4
el0_sync+0x15c/0x180
Freed by task 228:
kasan_save_stack+0x28/0x58
kasan_set_track+0x28/0x40
kasan_set_free_info+0x24/0x48
__kasan_slab_free+0x118/0x190
kasan_slab_free+0x14/0x20
slab_free_freelist_hook+0x6c/0x210
kfree+0x13c/0x460
Use the same pattern as f2fs + ext4 where the kobject destruction must
complete before allowing the FS itself to be freed. This means that we
need an explicit free_sbd in the callers.
Cc: Bob Peterson <rpeterso@redhat.com>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Jamie Iles <jamie@nuviainc.com>
[Also go to fail_free when init_names fails.]
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
