415 Commits

Author SHA1 Message Date
Andreas Gruenbacher
e19681ae6c gfs2: do_xmote fixes
[ Upstream commit 9947a06d29c0a30da88cdc6376ca5fd87083e130 ]

Function do_xmote() is called with the glock spinlock held.  Commit
86934198eefa added a 'goto skip_inval' statement at the beginning of the
function to further below where the glock spinlock is expected not to be
held anymore.  Then it added code there that requires the glock spinlock
to be held.  This doesn't make sense; fix this up by dropping and
retaking the spinlock where needed.

In addition, when ->lm_lock() returned an error, do_xmote() didn't fail
the locking operation, and simply left the glock hanging; fix that as
well.  (This is a much older error.)

Fixes: 86934198eefa ("gfs2: Clear flags when withdraw prevents xmote")
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-12 11:11:45 +02:00
Andreas Gruenbacher
b68b9dd723 gfs2: finish_xmote cleanup
[ Upstream commit 1cd28e15864054f3c48baee9eecda1c0441c48ac ]

Currently, function finish_xmote() takes and releases the glock
spinlock.  However, all of its callers immediately take that spinlock
again, so it makes more sense to take the spin lock before calling
finish_xmote() already.

With that, thaw_glock() is the only place that sets the GLF_HAVE_REPLY
flag outside of the glock spinlock, but it also takes that spinlock
immediately thereafter.  Change that to set the bit when the spinlock is
already held.  This allows to switch from test_and_clear_bit() to
test_bit() and clear_bit() in glock_work_func().

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Stable-dep-of: 9947a06d29c0 ("gfs2: do_xmote fixes")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-12 11:11:45 +02:00
Andreas Gruenbacher
d6b412c510 gfs2: Rename gfs2_withdrawn to gfs2_withdrawing_or_withdrawn
[ Upstream commit 4d927b03a68846e4e791ccde6b4c274df02f11e9 ]

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withdrawn eventually or has been withdrawn already.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>
Stable-dep-of: 9947a06d29c0 ("gfs2: do_xmote fixes")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-12 11:11:45 +02:00
Andreas Gruenbacher
7c2bc932b6 gfs2: Mark withdraws as unlikely
[ Upstream commit 015af1af44003fff797f8632e940824c07d282bf ]

Mark the gfs2_withdrawn(), gfs2_withdrawing(), and
gfs2_withdraw_in_prog() inline functions as likely to return %false.
This allows to get rid of likely() and unlikely() annotations at the
call sites of those functions.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Stable-dep-of: 9947a06d29c0 ("gfs2: do_xmote fixes")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-12 11:11:45 +02:00
Andreas Gruenbacher
0636b34b44 gfs2: Fix potential glock use-after-free on unmount
[ Upstream commit d98779e687726d8f8860f1c54b5687eec5f63a73 ]

When a DLM lockspace is released and there ares still locks in that
lockspace, DLM will unlock those locks automatically.  Commit
fb6791d100d1b started exploiting this behavior to speed up filesystem
unmount: gfs2 would simply free glocks it didn't want to unlock and then
release the lockspace.  This didn't take the bast callbacks for
asynchronous lock contention notifications into account, which remain
active until until a lock is unlocked or its lockspace is released.

To prevent those callbacks from accessing deallocated objects, put the
glocks that should not be unlocked on the sd_dead_glocks list, release
the lockspace, and only then free those glocks.

As an additional measure, ignore unexpected ast and bast callbacks if
the receiving glock is dead.

Fixes: fb6791d100d1b ("GFS2: skip dlm_unlock calls in unmount")
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Cc: David Teigland <teigland@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-12 11:11:44 +02:00
Andreas Gruenbacher
18dfb29644 gfs2: Remove ill-placed consistency check
[ Upstream commit 59f60005797b4018d7b46620037e0c53d690795e ]

This consistency check was originally added by commit 9287c6452d2b1
("gfs2: Fix occasional glock use-after-free").  It is ill-placed in
gfs2_glock_free() because if it holds there, it must equally hold in
__gfs2_glock_put() already.  Either way, the check doesn't seem
necessary anymore.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Stable-dep-of: d98779e68772 ("gfs2: Fix potential glock use-after-free on unmount")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-12 11:11:44 +02:00
Andreas Gruenbacher
abea81e6a7 gfs2: Fix "ignore unlock failures after withdraw"
[ Upstream commit 5d9231111966b6c5a65016d58dcbeab91055bc91 ]

Commit 3e11e53041502 tries to suppress dlm_lock() lock conversion errors
that occur when the lockspace has already been released.

It does that by setting and checking the SDF_SKIP_DLM_UNLOCK flag.  This
conflicts with the intended meaning of the SDF_SKIP_DLM_UNLOCK flag, so
check whether the lockspace is still allocated instead.

(Given the current DLM API, checking for this kind of error after the
fact seems easier that than to make sure that the lockspace is still
allocated before calling dlm_lock().  Changing the DLM API so that users
maintain the lockspace references themselves would be an option.)

Fixes: 3e11e53041502 ("GFS2: ignore unlock failures after withdraw")
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-12 11:11:41 +02:00
Bob Peterson
62862485a4 gfs2: fix glock shrinker ref issues
Before this patch, function gfs2_scan_glock_lru would only try to free
glocks that had a reference count of 0. But if the reference count ever
got to 0, the glock should have already been freed.

Shrinker function gfs2_dispose_glock_lru checks whether glocks on the
LRU are demote_ok, and if so, tries to demote them. But that's only
possible if the reference count is at least 1.

This patch changes gfs2_scan_glock_lru so it will try to demote and/or
dispose of glocks that have a reference count of 1 and which are either
demotable, or are already unlocked.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2023-09-18 16:00:50 +02:00
Andreas Gruenbacher
e7beb8b6de gfs2: Rename SDF_DEACTIVATING to SDF_KILL
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>
2023-09-05 15:58:16 +02:00
Andreas Gruenbacher
3c69c437bf gfs2: Rename sd_{ glock => kill }_wait
Rename sd_glock_wait to sd_kill_wait: we'll use it for other things
related to "killing" a filesystem on unmount soon (kill_sb).

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2023-09-05 15:58:16 +02:00
Bob Peterson
66fa9912ec gfs2: conversion deadlock do_promote bypass
Consider the following case:
1. A glock is held in shared mode.
2. A process requests the glock in exclusive mode (rename).
3. Before the lock is granted, more processes (read / ls) request the
   glock in shared mode again.
4. gfs2 sends a request to dlm for the lock in exclusive mode because
   that holder is at the head of the queue.
5. Somehow the dlm request gets canceled, so dlm sends us back a
   response with state == LM_ST_SHARED and LM_OUT_CANCELED.  So at that
   point, the glock is still held in shared mode.
6. finish_xmote gets called to process the response from dlm. It detects
   that the glock is not in the requested mode and no demote is in
   progress, so it moves the canceled holder to the tail of the queue
   and finds the new holder at the head of the queue.  That holder is
   requesting the glock in shared mode.
7. finish_xmote calls do_xmote to transition the glock into shared mode,
   but the glock is already in shared mode and so do_xmote complains
   about that with:
	GLOCK_BUG_ON(gl, gl->gl_state == gl->gl_target);

Instead, in finish_xmote, after moving the canceled holder to the tail
of the queue, check if any new holders can be granted.  Only call
do_xmote to repeat the dlm request if the holder at the head of the
queue is requesting the glock in a mode that is incompatible with the
mode the glock is currently held in.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2023-09-05 15:58:16 +02:00
Andreas Gruenbacher
0b93bac227 gfs2: Remove LM_FLAG_PRIORITY flag
The last user of this flag was removed in commit b77b4a4815a9 ("gfs2:
Rework freeze / thaw logic").

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2023-09-05 15:58:16 +02:00
Andreas Gruenbacher
de3e7f97ae gfs2: do_promote cleanup
Change function do_promote to return true on success, and false
otherwise.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2023-09-05 15:58:16 +02:00
Andreas Gruenbacher
af1abe1146 gfs2: Rename remaining "transaction" glock references
The transaction glock was repurposed to serve as the new freeze glock
years ago.  Don't refer to it as the transaction glock anymore.

Also, to be more precise, call it the "freeze glock" instead of the
"freeze lock".  Ditto for the journal glock.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2023-06-15 09:57:38 +02:00
Bob Peterson
6c0246a96e gfs2: Cease delete work during unmount
Add a check to delete_work_func() so that it quits when it finds that
the filesystem is deactivating.  This speeds up the delete workqueue
draining in gfs2_kill_sb().

In addition, make sure that iopen_go_callback() won't queue any new
delete work while the filesystem is deactivating.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2023-01-31 22:40:24 +01:00
Andreas Gruenbacher
f0e56edc2e gfs2: Split the two kinds of glock "delete" work
Function delete_work_func() is used for two purposes:

 * to immediately try to evict the glock's inode, and

 * to verify after a little while that the inode has been deleted as
   expected, and didn't just get skipped.

These two operations are not separated very well, so introduce two new
glock flags to improved that.  Split gfs2_queue_delete_work() into
gfs2_queue_try_to_evict and gfs2_queue_verify_evict().

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2023-01-31 22:40:24 +01:00
Andreas Gruenbacher
0247f4e959 gfs2: Move delete workqueue into super block
Move the global delete workqueue into struct gfs2_sbd so that we can
flush / drain it without interfering with other filesystems.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2023-01-31 22:40:24 +01:00
Andreas Gruenbacher
3056dc4655 gfs2: Get rid of GLF_PENDING_DELETE flag
Get rid of the GLF_PENDING_DELETE glock flag introduced by commit
a0e3cc65fa29 ("gfs2: Turn gl_delete into a delayed work").  The only use
of that flag is to prevent the iopen glock from being demoted (i.e.,
unlocked) while delete work is pending.  It turns out that demoting the
iopen glock while delete work is pending is perfectly fine; we only need
to make sure that the glock isn't being freed while still in use.  This
is ensured by the previous patch because delete_work_func() owns a
reference while the work is queued or running.

With these changes, gfs2_queue_delete_work() no longer takes the glock
spin lock, so we can use it in iopen_go_callback() instead of
open-coding it there.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2023-01-31 22:40:24 +01:00
Andreas Gruenbacher
228804a35c gfs2: Make glock lru list scanning safer
In __gfs2_glock_put(), remove the glock from the lru list *after*
dropping the glock lock.  This prevents deadlocks against
gfs2_scan_glock_lru().

In gfs2_scan_glock_lru(), make sure that the glock's reference count is
zero before moving the glock to the dispose list.  This skips glocks
that are marked dead as well as glocks that are still in use.
Additionally, switch to spin_trylock() as we already do in
gfs2_dispose_glock_lru(); this alone would also be enough to prevent
deadlocks against __gfs2_glock_put().

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2023-01-31 22:40:24 +01:00
Andreas Gruenbacher
8fb8f70ec7 gfs2: Clean up gfs2_scan_glock_lru
Switch to list_for_each_entry_safe() and eliminate the "skipped" list in
gfs2_scan_glock_lru().

At the same time, scan the requested number of items to scan, not one
more than that number.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2023-01-31 22:40:24 +01:00
Andreas Gruenbacher
9ffa18884c gfs2: gl_object races fix
Function glock_clear_object() checks if the specified glock is still
pointing at the right object and clears the gl_object pointer.  To
handle the case of incompletely constructed inodes, glock_clear_object()
also allows gl_object to be NULL.

However, in the teardown case, when iget_failed() is called and the
inode is removed from the inode hash, by the time we get to the
glock_clear_object() calls in gfs2_put_super() and its helpers, we don't
have exclusion against concurrent gfs2_inode_lookup() and
gfs2_create_inode() calls, and the inode and iopen glocks may already be
pointing at another inode, so the checks in glock_clear_object() are
incorrect.

To better handle this case, always completely disassociate an inode from
its glocks before tearing it down.  In addition, get rid of a duplicate
glock_clear_object() call in gfs2_evict_inode().  That way,
glock_clear_object() will only ever be called when the glock points at
the current inode, and the NULL check in glock_clear_object() can be
removed.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2023-01-27 15:55:48 +01:00
Andreas Gruenbacher
6b46a06100 gfs2: Remove support for glock holder auto-demotion (2)
As a follow-up to the previous commit, move the recovery related code in
__gfs2_glock_dq() to gfs2_glock_dq() where it better fits.  No
functional change.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2022-12-15 12:41:22 +01:00
Andreas Gruenbacher
ba3e77a4a2 gfs2: Remove support for glock holder auto-demotion
Remove the support for glock holder auto-demotion (commit dc732906c245
and folow-ups) as we are not planning to use this feature, and the
additional code therefore only adds unnecessary complexity.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2022-12-15 12:41:22 +01:00
Andreas Gruenbacher
f0c0ade8d8 gfs2: Minor gfs2_try_evict cleanup
In gfs2_try_evict(), when an inode can't be evicted, we are grabbing a
temporary reference on the inode glock to poke that glock.  That should
be safe, but it's easier to just grab an inode reference as we already
do earlier in this function.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2022-12-10 13:06:04 +01:00
Andreas Gruenbacher
88f4a9f813 gfs2: Partially revert gfs2_inode_lookup change
Commit c412a97cf6c5 changed delete_work_func() to always perform an
inode lookup when gfs2_try_evict() fails.  This doesn't make sense as a
gfs2_try_evict() failure indicates that the inode is likely still in
use.  Revert that change.

Fixes: c412a97cf6c5 ("gfs2: Use TRY lock in gfs2_inode_lookup for UNLINKED inodes")
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2022-12-06 16:08:12 +01:00
Andreas Gruenbacher
3781ec9e09 gfs2: Uninline and improve glock_{set,clear}_object
Those functions have reached a size at which having them inline isn't
useful anymore, so uninline them.  In addition, report the glock name on
assertion failures.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2022-12-06 16:06:32 +01:00
Andreas Gruenbacher
97236ad5a6 gfs2: Avoid dequeuing GL_ASYNC glock holders twice
When a locking request fails, the associated glock holder is
automatically dequeued from the list of active and waiting holders.  For
GL_ASYNC locking requests, this will obviously happen asynchronously
and it can race with attempts to cancel that locking request via
gfs2_glock_dq().  Therefore, don't forget to check if a locking request
has already been dequeued in gfs2_glock_dq().

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2022-12-06 16:06:31 +01:00
Andreas Gruenbacher
4ad02083a0 gfs2: Make gfs2_glock_hold return its glock argument
This allows code like 'gl = gfs2_glock_hold(...)'.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2022-12-06 16:06:31 +01:00
Andreas Gruenbacher
c7d7d2d345 gfs2: Merge branch 'for-next.nopid' into for-next
Resolves a conflict in gfs2_inode_lookup() between the following commits:

    gfs2: Use TRY lock in gfs2_inode_lookup for UNLINKED inodes

    gfs2: Mark the remaining process-independent glock holders as GL_NOPID

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2022-10-09 22:56:28 +02:00
Bob Peterson
86934198ee gfs2: Clear flags when withdraw prevents xmote
There are a couple places in function do_xmote where normal processing
is circumvented due to withdraws in progress. However, since we bypass
most of do_xmote() we bypass telling dlm to lock the dlm lock, which
means dlm will never respond with a completion callback. Since the
completion callback ordinarily clears GLF_LOCK, this patch changes
function do_xmote to handle those situations more gracefully so the
file system may be unmounted after withdraw.

A very similar situation happens with the GLF_DEMOTE_IN_PROGRESS flag,
which is cleared by function finish_xmote(). Since the withdraw causes
us to skip the majority of do_xmote, it therefore also skips the call
to finish_xmote() so the DEMOTE_IN_PROGRESS flag needs to be cleared
manually.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2022-08-25 17:11:39 +02:00
Bob Peterson
053640a738 gfs2: Dequeue waiters when withdrawn
When a withdraw occurs, ordinary (not system) glocks may not be granted
anymore. Later, when the file system is unmounted, gfs2_gl_hash_clear()
tries to clear out all the glocks, but these un-grantable pending
waiters prevent some glocks from being freed. So the unmount hangs, at
least for its ten-minute timeout period.

This patch takes measures to remove any pending waiters from
the glocks that will never be granted. This allows the unmount to
proceed in a reasonable period of time.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2022-08-25 17:11:14 +02:00
Bob Peterson
c412a97cf6 gfs2: Use TRY lock in gfs2_inode_lookup for UNLINKED inodes
Before this patch, delete_work_func() would check for the GLF_DEMOTE
flag on the iopen glock and if set, it would perform special processing.
However, there was a race whereby the GLF_DEMOTE flag could be set by
another process after the check. Then when it called
gfs2_lookup_by_inum() which calls gfs2_inode_lookup(), it tried to lock
the iopen glock in SH mode, but the GLF_DEMOTE flag prevented the
request from being granted. But the iopen glock could never be demoted
because that happens when the inode is evicted, and the evict was never
completed because of the failed lookup.

To fix that, change function gfs2_inode_lookup() so that when
GFS2_BLKST_UNLINKED inodes are searched, it uses the LM_FLAG_TRY flag
for the iopen glock.  If the locking request fails, fail
gfs2_inode_lookup() with -EAGAIN so that delete_work_func() can retry
the operation later.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2022-08-25 15:25:16 +02:00
Linus Torvalds
c42b729ef6 gfs2 fixes
- Instantiate glocks ouside of the glock state engine, in the contect of
   the process taking the glock.  This moves unnecessary complexity out
   of the core glock code.  Clean up the instantiate logic to be more
   sensible.
 
 - In gfs2_glock_async_wait(), cancel pending locking request upon
   failure.  Make sure all glocks are left in a consistent state.
 
 - Various other minor cleanups and fixes.
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Merge tag 'gfs2-v5.19-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2

Pull gfs2 updates from Andreas Gruenbacher:

 - Instantiate glocks ouside of the glock state engine, in the contect
   of the process taking the glock. This moves unnecessary complexity
   out of the core glock code. Clean up the instantiate logic to be more
   sensible.

 - In gfs2_glock_async_wait(), cancel pending locking request upon
   failure. Make sure all glocks are left in a consistent state.

 - Various other minor cleanups and fixes.

* tag 'gfs2-v5.19-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
  gfs2: List traversal in do_promote is safe
  gfs2: do_promote glock holder stealing fix
  gfs2: Use better variable name
  gfs2: Make go_instantiate take a glock
  gfs2: Add new go_held glock operation
  gfs2: Revert 'Fix "truncate in progress" hang'
  gfs2: Instantiate glocks ouside of glock state engine
  gfs2: Fix up gfs2_glock_async_wait
  gfs2: Minor gfs2_glock_nq_m cleanup
  gfs2: Fix spelling mistake in comment
  gfs2: Rewrap overlong comment in do_promote
  gfs2: Remove redundant NULL check before kfree
2022-08-06 14:44:49 -07:00
Andreas Gruenbacher
446279168e Merge part of branch 'for-next.instantiate' into for-next 2022-08-05 18:37:03 +02:00
Roman Gushchin
e33c267ab7 mm: shrinkers: provide shrinkers with names
Currently shrinkers are anonymous objects.  For debugging purposes they
can be identified by count/scan function names, but it's not always
useful: e.g.  for superblock's shrinkers it's nice to have at least an
idea of to which superblock the shrinker belongs.

This commit adds names to shrinkers.  register_shrinker() and
prealloc_shrinker() functions are extended to take a format and arguments
to master a name.

In some cases it's not possible to determine a good name at the time when
a shrinker is allocated.  For such cases shrinker_debugfs_rename() is
provided.

The expected format is:
    <subsystem>-<shrinker_type>[:<instance>]-<id>
For some shrinkers an instance can be encoded as (MAJOR:MINOR) pair.

After this change the shrinker debugfs directory looks like:
  $ cd /sys/kernel/debug/shrinker/
  $ ls
    dquota-cache-16     sb-devpts-28     sb-proc-47       sb-tmpfs-42
    mm-shadow-18        sb-devtmpfs-5    sb-proc-48       sb-tmpfs-43
    mm-zspool:zram0-34  sb-hugetlbfs-17  sb-pstore-31     sb-tmpfs-44
    rcu-kfree-0         sb-hugetlbfs-33  sb-rootfs-2      sb-tmpfs-49
    sb-aio-20           sb-iomem-12      sb-securityfs-6  sb-tracefs-13
    sb-anon_inodefs-15  sb-mqueue-21     sb-selinuxfs-22  sb-xfs:vda1-36
    sb-bdev-3           sb-nsfs-4        sb-sockfs-8      sb-zsmalloc-19
    sb-bpf-32           sb-pipefs-14     sb-sysfs-26      thp-deferred_split-10
    sb-btrfs:vda2-24    sb-proc-25       sb-tmpfs-1       thp-zero-9
    sb-cgroup2-30       sb-proc-39       sb-tmpfs-27      xfs-buf:vda1-37
    sb-configfs-23      sb-proc-41       sb-tmpfs-29      xfs-inodegc:vda1-38
    sb-dax-11           sb-proc-45       sb-tmpfs-35
    sb-debugfs-7        sb-proc-46       sb-tmpfs-40

[roman.gushchin@linux.dev: fix build warnings]
  Link: https://lkml.kernel.org/r/Yr+ZTnLb9lJk6fJO@castle
  Reported-by: kernel test robot <lkp@intel.com>
Link: https://lkml.kernel.org/r/20220601032227.4076670-4-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-03 18:08:40 -07:00
Andreas Gruenbacher
6feaec8147 gfs2: List traversal in do_promote is safe
In do_promote(), we're never removing the current entry from the list
and so the list traversal is actually safe.  Switch back to
list_for_each_entry().

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2022-06-29 17:01:59 +02:00
Bob Peterson
0befb8511e gfs2: do_promote glock holder stealing fix
In do_promote(), when the glock had no strong holders, we were
accidentally calling demote_incompat_holders() with new_gh == NULL, so
no weak holders were considered incompatible.  Instead, the new holder
should have been passed in.

For doing that, the HIF_HOLDER flag needs to be set in new_gh to prevent
may_grant() from complaining.  This means that the new holder will now
be recognized as a current holder, so skip over it explicitly in
demote_incompat_holders() to prevent it from being dequeued.

To further clarify things, we can now rename new_gh to current_gh in
demote_incompat_holders(); after all, the HIF_HOLDER flag is already set,
which means the new holder is already a current holder.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2022-06-29 17:00:55 +02:00
Andreas Gruenbacher
8f0028fc60 gfs2: Use better variable name
In do_promote() and add_to_queue(), use current_gh as the variable name
for the first strong holder we could find: this matches the variable
name is may_grant(), and more clearly indicates that we're interested in
one (any) of the current strong holders.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2022-06-29 17:00:21 +02:00
Andreas Gruenbacher
5f38a4d3c4 gfs2: Make go_instantiate take a glock
Make go_instantiate take a glock instead of a glock holder as its argument:
this handler is supposed to instantiate the object associated with the glock.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2022-06-29 16:59:07 +02:00
Andreas Gruenbacher
86c30a01f5 gfs2: Add new go_held glock operation
Right now, inode_go_instantiate() contains functionality that relates to
how a glock is held rather than the glock itself, like waiting for
pending direct I/O to complete and completing interrupted truncates.
This code is meant to be run each time a holder is acquired, but
go_instantiate is actually only called once, when the glock is
instantiated.

To fix that, introduce a new go_held glock operation that is called each
time a glock holder is acquired.  Move the holder specific code in
inode_go_instantiate() over to inode_go_held().

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2022-06-29 16:56:41 +02:00
Andreas Gruenbacher
de3f906f0a gfs2: Revert 'Fix "truncate in progress" hang'
Now that interrupted truncates are completed in the context of the
process taking the glock, there is no need for the glock state engine to
delegate that task to gfs2_quotad or for quotad to perform those
truncates anymore.  Get rid of the obsolete associated infrastructure.

Reverts commit 813e0c46c9e2 ("GFS2: Fix "truncate in progress" hang").

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2022-06-29 16:54:59 +02:00
Andreas Gruenbacher
53d6913295 gfs2: Instantiate glocks ouside of glock state engine
Instantiate glocks outside of the glock state engine: there is no real
reason for instantiating them inside the glock state engine; it only
complicates the code.

Instead, instantiate them in gfs2_glock_wait() and gfs2_glock_async_wait()
using the new gfs2_glock_holder_ready() helper.  On top of that, the only
other place that acquires a glock without using gfs2_glock_wait() or
gfs2_glock_async_wait() is gfs2_upgrade_iopen_glock(), so call
gfs2_glock_holder_ready() there as well.

If a dinode has a pending truncate, the glock-specific instantiate function
for inodes wakes up the truncate function in the quota daemon.  Waiting for
the completion of the truncate was previously done by the glock state
engine, but we now need to wait in inode_go_instantiate().

This also means that gfs2_instantiate() will now no longer return any
"special" error codes.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2022-06-29 16:53:22 +02:00
Andreas Gruenbacher
bdff777cbb gfs2: Fix up gfs2_glock_async_wait
Since commit 1fc05c8d8426 ("gfs2: cancel timed-out glock requests"), a
pending locking request can be canceled by calling gfs2_glock_dq() on
the pending holder.  In gfs2_glock_async_wait(), when we time out, use
that to cancel the remaining locking requests and dequeue the locking
requests already granted.  That's simpler as well as more efficient than
waiting for all locking requests to eventually be granted and dequeuing
them then.

In addition, gfs2_glock_async_wait() promises that by the time the
function completes, all glocks are either granted or dequeued, but the
implementation doesn't keep that promise if individual locking requests
fail.  Fix that as well.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2022-06-29 16:47:44 +02:00
Andreas Gruenbacher
cbe6d2576e gfs2: Add GL_NOPID flag for process-independent glock holders
Add a GL_NOPID flag to indicate that once a glock holder has been acquired, it
won't be associated with the current process anymore.  This is useful for iopen
and flock glocks which are associated with open files, as well as journal glock
holders and similar which are associated with the filesystem.

Once GL_NOPID is used for all applicable glocks (see the next patches),
processes will no longer be falsely reported as holding glocks which they are
not actually holding in the glocks dump file.  Unlike before, when a process is
reported as having "(ended)", this will indicate an actual bug.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2022-06-29 13:07:54 +02:00
Andreas Gruenbacher
56535dc695 gfs2: Add flocks to glockfd debugfs file
Include flock glocks in the "glockfd" debugfs file.  Those are similar to the
iopen glocks; while an open file is holding an flock, it is holding the file's
flock glock.

We cannot take f_fl_mutex in gfs2_glockfd_seq_show_flock() or else dumping the
"glockfd" file would block on flock operations.  Instead, use the file->f_lock
spin lock to protect the f_fl_gh.gh_gl glock pointer.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2022-06-29 13:07:53 +02:00
Andreas Gruenbacher
4480c27ca3 gfs2: Add glockfd debugfs file
When a process has a gfs2 file open, the file is keeping a reference on the
underlying gfs2 inode, and the inode is keeping the inode's iopen glock held in
shared mode.  In other words, the process depends on the iopen glock of each
open gfs2 file.  Expose those dependencies in a new "glockfd" debugfs file.

The new debugfs file contains one line for each gfs2 file descriptor,
specifying the tgid, file descriptor number, and glock name, e.g.,

  1601 6 5/816d

This list is compiled by iterating all tasks on the system using find_ge_pid(),
and all file descriptors of each task using task_lookup_next_fd_rcu().  To make
that work from gfs2, export those two functions.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2022-06-29 13:07:16 +02:00
Andreas Gruenbacher
44dab005fd gfs2: Minor gfs2_glock_nq_m cleanup
Add state and flags arguments to gfs2_rlist_alloc() to make it somewhat more
obvious which state and flags an rlist uses.  With that, stop knocking off
flags in gfs2_glock_nq_m() and its nq_m_sync() helper that are never set in the
first place.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2022-06-28 20:38:15 +02:00
Bob Peterson
565f82b57a gfs2: Rewrap overlong comment in do_promote
Rewrap the comment to keep the line length below 80 characters.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2022-06-09 12:26:43 +02:00
Kees Cook
11d8b79e84 gfs2: Use container_of() for gfs2_glock(aspace)
Clang's structure layout randomization feature gets upset when it sees
struct address_space (which is randomized) cast to struct gfs2_glock.
This is due to seeing the mapping pointer as being treated as an array
of gfs2_glock, rather than "something else, before struct address_space":

In file included from fs/gfs2/acl.c:23:
fs/gfs2/meta_io.h:44:12: error: casting from randomized structure pointer type 'struct address_space *' to 'struct gfs2_glock *'
	return (((struct gfs2_glock *)mapping) - 1)->gl_name.ln_sbd;
		^

Replace the instances of open-coded pointer math with container_of()
usage, and update the allocator to match.

Some cleanups and conversion of gfs2_glock_get() and
gfs2_glock_dealloc() by Andreas.

Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/lkml/202205041550.naKxwCBj-lkp@intel.com
Cc: Bob Peterson <rpeterso@redhat.com>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Bill Wendling <morbo@google.com>
Cc: cluster-devel@redhat.com
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2022-05-24 21:29:14 +02:00
Andreas Gruenbacher
a4e8145edc gfs2: Initialize gh_error in gfs2_glock_nq
The gh_error field if a glock holder is initialized to zero in
gfs2_holder_init().  When a locking operation fails, gh_error is set to
an error code; when it succeeds, the gh_error value is left unchanged.
The field isn't initialized in gfs2_holder_reinit(), which is a problem.
Instead of fixing that directly, initialize gh_error in gfs2_glock_nq().
That also obsoletes the assignment in do_flock().

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2022-02-15 15:01:40 +01:00