Commit Graph

2231 Commits

Author SHA1 Message Date
Andreas Gruenbacher
35b6f8fbcf gfs2: Wake up when setting GLF_DEMOTE
Wake up the sdp->sd_async_glock_wait wait queue when setting the GLF_DEMOTE
flag.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-06-05 20:19:21 +02:00
Andreas Gruenbacher
b0dcffd8da gfs2: Check inode generation number in delete_work_func
In delete_work_func, if the iopen glock still has an inode attached,
limit the inode lookup to that specific generation number: in the likely
case that the inode was deleted on the node on which the inode's link
count dropped to zero, we can skip verifying the on-disk block type and
reading in the inode.  The same applies if another node that had the
inode open managed to delete the inode before us.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-06-05 20:19:21 +02:00
Andreas Gruenbacher
b66648ad6d gfs2: Move inode generation number check into gfs2_inode_lookup
Move the inode generation number check from gfs2_lookup_by_inum into
gfs2_inode_lookup: gfs2_inode_lookup may be able to decide that an inode with
the given inode generation number cannot exist without having to verify the
block type or reading the inode from disk.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-06-05 20:19:21 +02:00
Andreas Gruenbacher
6bdcadea75 gfs2: Minor gfs2_lookup_by_inum cleanup
Use a zero no_formal_ino instead of a NULL pointer to indicate that any inode
generation number will qualify: a valid inode never has a zero no_formal_ino.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-06-05 20:19:21 +02:00
Andreas Gruenbacher
9e73330f29 gfs2: Try harder to delete inodes locally
When an inode's link count drops to zero and the inode is cached on
other nodes, the current behavior of gfs2 is to immediately give up and
to rely on the other node(s) to delete the inode if there is iopen glock
contention.  This leads to resource group glock bouncing and the loss of
caching.  With the previous patches in place, we can fix that by not
giving up immediately.

When the inode is still open on other nodes, those nodes won't be able
to evict the inode and give up the iopen glock.  In that case, our lock
conversion request will time out.  The unlink system call will block for
the duration of the iopen lock conversion request.  We're also holding
the inode glock in EX mode for an extended duration, so other nodes
won't be able to make progress on the inode, either.

This is worse than what we had before, but we can prevent other nodes
from getting stuck by aborting our iopen locking request if there is
contention on the inode glock.  This will the the subject of a future
patch.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-06-05 20:19:21 +02:00
Andreas Gruenbacher
8c7b9262a8 gfs2: Give up the iopen glock on contention
When there's contention on the iopen glock, it means that the link count
of the corresponding inode has dropped to zero on a remote node which is
now trying to delete the inode.  In that case, try to evict the inode so
that the iopen glock will be released, which will allow the remote node
to do its job.

When the inode is still open locally, the inode's reference count won't
drop to zero and so we'll keep holding the inode and its iopen glock.
The remote node will time out its request to grab the iopen glock, and
when the inode is finally closed locally, we'll try to delete it
ourself.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-06-05 20:19:21 +02:00
Andreas Gruenbacher
a0e3cc65fa gfs2: Turn gl_delete into a delayed work
This requires flushing delayed work items in gfs2_make_fs_ro (which is called
before unmounting a filesystem).

When inodes are deleted and then recreated, pending gl_delete work items would
have no effect because the inode generations will have changed, so we can
cancel any pending gl_delete works before reusing iopen glocks.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-06-05 20:19:21 +02:00
Andreas Gruenbacher
f286d627ef gfs2: Keep track of deleted inode generations in LVBs
When deleting an inode, keep track of the generation of the deleted inode in
the inode glock Lock Value Block (LVB).  When trying to delete an inode
remotely, check the last-known inode generation against the deleted inode
generation to skip duplicate remote deletes.  This avoids taking the resource
group glock in order to verify the block type.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-06-05 20:19:20 +02:00
Bob Peterson
15f2547b41 gfs2: Allow ASPACE glocks to also have an lvb
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-06-05 20:18:59 +02:00
Bob Peterson
b14c94908b Revert "gfs2: Don't demote a glock until its revokes are written"
This reverts commit df5db5f9ee.

This patch fixes a regression: patch df5db5f9ee allowed function
run_queue() to bypass its call to do_xmote() if revokes were queued for
the glock. That's wrong because its call to do_xmote() is what is
responsible for calling the go_sync() glops functions to sync both
the ail list and any revokes queued for it. By bypassing the call,
gfs2 could get into a stand-off where the glock could not be demoted
until its revokes are written back, but the revokes would not be
written back because do_xmote() was never called.

It "sort of" works, however, because there are other mechanisms like
the log flush daemon (logd) that can sync the ail items and revokes,
if it deems it necessary. The problem is: without file system pressure,
it might never deem it necessary.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2020-05-08 15:01:25 -05:00
Bob Peterson
b11e1a84f3 gfs2: If go_sync returns error, withdraw but skip invalidate
Before this patch, if the go_sync operation returned an error during
the do_xmote process (such as unable to sync metadata to the journal)
the code did goto out. That kept the glock locked, so it could not be
given away, which correctly avoids file system corruption. However,
it never set the withdraw bit or requeueing the glock work. So it would
hang forever, unable to ever demote the glock.

This patch changes to goto to a new label, skip_inval, so that errors
from go_sync are treated the same way as errors from go_inval:
The delayed withdraw bit is set and the work is requeued. That way,
the logd should eventually figure out there's a problem and withdraw
properly there.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-05-08 15:00:07 -05:00
Andreas Gruenbacher
f4e2f5e1a5 gfs2: Grab glock reference sooner in gfs2_add_revoke
This patch rearranges gfs2_add_revoke so that the extra glock
reference is added earlier on in the function to avoid races in which
the glock is freed before the new reference is taken.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2020-05-08 18:49:04 +02:00
Bob Peterson
c9cb9e3819 gfs2: don't call quota_unhold if quotas are not locked
Before this patch, function gfs2_quota_unlock checked if quotas are
turned off, and if so, it branched to label out, which called
gfs2_quota_unhold. With the new system of gfs2_qa_get and put, we
no longer want to call gfs2_quota_unhold or we won't balance our
gets and puts.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-05-08 18:49:04 +02:00
Bob Peterson
4ed0c30811 gfs2: move privileged user check to gfs2_quota_lock_check
Before this patch, function gfs2_quota_lock checked if it was called
from a privileged user, and if so, it bypassed the quota check:
superuser can operate outside the quotas.
That's the wrong place for the check because the lock/unlock functions
are separate from the lock_check function, and you can do lock and
unlock without actually checking the quotas.

This patch moves the check to gfs2_quota_lock_check.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-05-08 18:47:58 +02:00
Bob Peterson
e6ce26e571 gfs2: remove check for quotas on in gfs2_quota_check
This patch removes a check from gfs2_quota_check for whether quotas
are enabled by the superblock. There is a test just prior for the
GIF_QD_LOCKED bit in the inode, and that can only be set by functions
that already check that quotas are enabled in the superblock.
Therefore, the check is redundant.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-05-08 18:47:39 +02:00
Bob Peterson
f9615fe311 gfs2: Change BUG_ON to an assert_withdraw in gfs2_quota_change
Before this patch, gfs2_quota_change() would BUG_ON if the
qa_ref counter was not a positive number. This patch changes it to
be a withdraw instead. That way we can debug things more easily.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-05-08 18:45:12 +02:00
Bob Peterson
2297ab6144 gfs2: Fix problems regarding gfs2_qa_get and _put
This patch fixes a couple of places in which gfs2_qa_get and gfs2_qa_put are
not balanced: we now keep references around whenever a file is open for writing
(see gfs2_open_common and gfs2_release), so we need to put all references we
grab in function gfs2_create_inode.  This was broken in the successful case and
on one error path.

This also means that we don't have a reference to put in gfs2_evict_inode.

In addition, gfs2_qa_put was called for the wrong inode in gfs2_link.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-05-08 18:45:11 +02:00
Andreas Gruenbacher
aa83da7f47 gfs2: More gfs2_find_jhead fixes
It turns out that when extending an existing bio, gfs2_find_jhead fails to
check if the block number is consecutive, which leads to incorrect reads for
fragmented journals.

In addition, limit the maximum bio size to an arbitrary value of 2 megabytes:
since commit 07173c3ec2 ("block: enable multipage bvecs"), if we just keep
adding pages until bio_add_page fails, bios will grow much larger than useful,
which pins more memory than necessary with barely any additional performance
gains.

Fixes: f4686c26ec ("gfs2: read journal in large chunks")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2020-05-08 15:15:12 +02:00
Andreas Gruenbacher
566a2ab3c9 gfs2: Another gfs2_walk_metadata fix
Make sure we don't walk past the end of the metadata in gfs2_walk_metadata: the
inode holds fewer pointers than indirect blocks.

Slightly clean up gfs2_iomap_get.

Fixes: a27a0c9b6a ("gfs2: gfs2_walk_metadata fix")
Cc: stable@vger.kernel.org # v5.3+
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2020-05-08 15:15:12 +02:00
Bob Peterson
d22f69a08d gfs2: Fix use-after-free in gfs2_logd after withdraw
When the gfs2_logd daemon withdrew, the withdraw sequence called
into make_fs_ro() to make the file system read-only. That caused the
journal descriptors to be freed. However, those journal descriptors
were used by gfs2_logd's call to gfs2_ail_flush_reqd(). This caused
a use-after free and NULL pointer dereference.

This patch changes function gfs2_logd() so that it stops all logd
work until the thread is told to stop. Once a withdraw is done,
it only does an interruptible sleep.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-05-08 15:15:12 +02:00
Bob Peterson
53af80ce0e gfs2: Fix BUG during unmount after file system withdraw
Before this patch, when the logd daemon was forced to withdraw, it
would try to request its journal be recovered by another cluster node.
However, in single-user cases with lock_nolock, there are no other
nodes to recover the journal. Function signal_our_withdraw() was
recognizing the lock_nolock situation, but not until after it had
evicted its journal inode. Since the journal descriptor that points
to the inode was never removed from the master list, when the unmount
occurred, it did another iput on the evicted inode, which resulted in
a BUG_ON(inode->i_state & I_CLEAR).

This patch moves the check for this situation earlier in function
signal_our_withdraw(), which avoids the extra iput, so the unmount
may happen normally.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-05-08 15:13:27 +02:00
Bob Peterson
a8b7528b69 gfs2: Fix error exit in do_xmote
Before this patch, if an error was detected from glock function go_sync
by function do_xmote, it would return.  But the function had temporarily
unlocked the gl_lockref spin_lock, and it never re-locked it.  When the
caller of do_xmote tried to unlock it again, it was already unlocked,
which resulted in a corrupted spin_lock value.

This patch makes sure the gl_lockref spin_lock is re-locked after it is
unlocked.

Thanks to Wu Bo <wubo40@huawei.com> for reporting this problem.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-05-08 14:45:38 +02:00
Bob Peterson
ac91558428 gfs2: fix withdraw sequence deadlock
After a gfs2 file system withdraw, any attempt to read metadata is
automatically rejected by function gfs2_meta_read() except for reads
of the journal inode. This turns out to be a problem because function
signal_our_withdraw() repeatedly calls check_journal_clean() which reads
the metadata (both its dinode and indirect blocks) to see if the entire
journal is mapped. The dinode read works, but reading the indirect blocks
returns -EIO which gets sent back up and causes a consistency error.
This results in withdraw-from-withdraw, which becomes a deadlock.

This patch changes the test in gfs2_meta_read() to allow all metadata
reads for the journal. Instead of checking the journal block, it now
checks for the journal inode glock which is the same for all blocks in
the journal. This allows check_journal_clean() to properly check the
journal without trying to withdraw recursively.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-05-06 21:25:26 +02:00
Linus Torvalds
018d21f5c5 We've got a lot of patches (39) for this merge window. Most of these patches
are related to corruption that occurs when journals are replayed.
 For example:
 
    1. A node fails while writing to the file system.
    2. Other nodes use the metadata that was once used by the failed node.
    3. When the node returns to the cluster, its journal is replayed,
       but the older metadata blocks overwrite the changes from step 2.
 
 - Fixed the recovery sequence to prevent corruption during journal replay.
 - Many bug fixes found during recovery testing.
 - New improved file system withdraw sequence.
 - Fixed how resource group buffers are managed.
 - Fixed how metadata revokes are tracked and written.
 - Improve processing of IO errors hit by daemons like logd and quotad.
 - Improved error checking in metadata writes.
 - Fixed how qadata quota data structures are managed.
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Merge tag 'gfs2-for-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2

Pull gfs2 updates from Bob Peterson:
 "We've got a lot of patches (39) for this merge window. Most of these
  patches are related to corruption that occurs when journals are
  replayed. For example:

   1. A node fails while writing to the file system.
   2. Other nodes use the metadata that was once used by the failed
      node.
   3. When the node returns to the cluster, its journal is replayed, but
      the older metadata blocks overwrite the changes from step 2.

  Summary:

   - Fixed the recovery sequence to prevent corruption during journal
     replay.

   - Many bug fixes found during recovery testing.

   - New improved file system withdraw sequence.

   - Fixed how resource group buffers are managed.

   - Fixed how metadata revokes are tracked and written.

   - Improve processing of IO errors hit by daemons like logd and
     quotad.

   - Improved error checking in metadata writes.

   - Fixed how qadata quota data structures are managed"

* tag 'gfs2-for-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2: (39 commits)
  gfs2: Fix oversight in gfs2_ail1_flush
  gfs2: change from write to read lock for sd_log_flush_lock in journal replay
  gfs2: instrumentation wrt ail1 stuck
  gfs2: don't lock sd_log_flush_lock in try_rgrp_unlink
  gfs2: Remove unnecessary gfs2_qa_{get,put} pairs
  gfs2: Split gfs2_rsqa_delete into gfs2_rs_delete and gfs2_qa_put
  gfs2: Change inode qa_data to allow multiple users
  gfs2: eliminate gfs2_rsqa_alloc in favor of gfs2_qa_alloc
  gfs2: Switch to list_{first,last}_entry
  gfs2: Clean up inode initialization and teardown
  gfs2: Additional information when gfs2_ail1_flush withdraws
  gfs2: leaf_dealloc needs to allocate one more revoke
  gfs2: allow journal replay to hold sd_log_flush_lock
  gfs2: don't allow releasepage to free bd still used for revokes
  gfs2: flesh out delayed withdraw for gfs2_log_flush
  gfs2: Do proper error checking for go_sync family of glops functions
  gfs2: Don't demote a glock until its revokes are written
  gfs2: drain the ail2 list after io errors
  gfs2: Withdraw in gfs2_ail1_flush if write_cache_pages fails
  gfs2: Do log_flush in gfs2_ail_empty_gl even if ail list is empty
  ...
2020-03-31 14:16:03 -07:00
Bob Peterson
75b46c437f gfs2: Fix oversight in gfs2_ail1_flush
Ordinarily, function gfs2_ail1_start_one issues a write request
for one item on the ail1 list, then returns -EBUSY. This makes the
caller, gfs2_ail1_flush, loop around and start another. However,
it was not clearing the -EBUSY return code each time through the loop.
So on rare occasions, like when the wbc runs out of nr_to_write, it
remained set to -EBUSY, which triggered an error and withdraw.

This patch sets the return code to 0 each time through the restart
loop so this won't happen anymore.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2020-03-30 07:55:35 -05:00
Bob Peterson
c953a735c7 gfs2: change from write to read lock for sd_log_flush_lock in journal replay
Function gfs2_recover_func grabs the sd_log_flush_lock rw_semaphore in
write mode. This is unnecessary because we only need to prevent log flush
from using sd_log_bio bio while it does. Therefore, a read lock will be
enough. This is a small step in cleaning up log flush.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2020-03-27 14:08:05 -05:00
Bob Peterson
9592ea80ad gfs2: instrumentation wrt ail1 stuck
Before this patch, if the ail1 flush got stuck for some reason, there
were no clues as to why. This patch introduces a check for getting
stuck for more than a minute, and if it happens, it dumps the items
still remaining on the ail1 list.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2020-03-27 14:08:05 -05:00
Bob Peterson
e04d339bd8 gfs2: don't lock sd_log_flush_lock in try_rgrp_unlink
In function try_rgrp_unlink, we added a temporary lock of the
sd_log_flush_lock while searching the bitmaps. This protected us from
problems in which dinodes being freed were still in a state of flux
because the rgrp was in an active transaction. It was a kludge.
Now that we've straightened out the code for inode eviction, deletes,
and all the recovery mess, we no longer need this kludge.
This patch removes it, and should improve performance.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2020-03-27 14:08:05 -05:00
Andreas Gruenbacher
4bd684bc01 gfs2: Remove unnecessary gfs2_qa_{get,put} pairs
We now get the quota data structure when opening a file writable and put it
when closing that writable file descriptor, so there no longer is a need for
gfs2_qa_{get,put} while we're holding a writable file descriptor.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2020-03-27 14:08:05 -05:00
Andreas Gruenbacher
1595548fe7 gfs2: Split gfs2_rsqa_delete into gfs2_rs_delete and gfs2_qa_put
Keeping reservations and quotas separate helps reviewing the code.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2020-03-27 14:08:04 -05:00
Bob Peterson
2fba46a04c gfs2: Change inode qa_data to allow multiple users
Before this patch, multiple users called gfs2_qa_alloc which allocated
a qadata structure to the inode, if quotas are turned on. Later, in
file close or evict, the structure was deleted with gfs2_qa_delete.
But there can be several competing processes who need access to the
structure. There were races between file close (release) and the others.
Thus, a release could delete the structure out from under a process
that relied upon its existence. For example, chown.

This patch changes the management of the qadata structures to be
a get/put scheme. Function gfs2_qa_alloc has been changed to gfs2_qa_get
and if the structure is allocated, the count essentially starts out at
1. Function gfs2_qa_delete has been renamed to gfs2_qa_put, and the
last guy to decrement the count to 0 frees the memory.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2020-03-27 14:08:04 -05:00
Bob Peterson
d580712a37 gfs2: eliminate gfs2_rsqa_alloc in favor of gfs2_qa_alloc
Before this patch, multiple callers called gfs2_rsqa_alloc to force
the existence of a reservations structure and a quota data structure
if needed. However, now the reservations are handled separately, so
the quota data is only the quota data. So we eliminate the one in
favor of just calling gfs2_qa_alloc directly.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2020-03-27 14:08:04 -05:00
Andreas Gruenbacher
969183bc68 gfs2: Switch to list_{first,last}_entry
Replace open-coded versions of list_first_entry and list_last_entry with those
functions.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2020-03-27 14:08:04 -05:00
Andreas Gruenbacher
40e7e86ef1 gfs2: Clean up inode initialization and teardown
When allocating a new inode, mark the iopen glock holder as uninitialized to
make sure gfs2_evict_inode won't fail after an incomplete create or lookup.  In
gfs2_evict_inode, allow the inode glock to be NULL and remove the duplicate
iopen glock teardown code.  In gfs2_inode_lookup, don't tear down things that
gfs2_evict_inode will already tear down.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2020-03-27 14:08:04 -05:00
Al Viro
2103913265 gfs2_atomic_open(): fix O_EXCL|O_CREAT handling on cold dcache
with the way fs/namei.c:do_last() had been done, ->atomic_open()
instances needed to recognize the case when existing file got
found with O_EXCL|O_CREAT, either by falling back to finish_no_open()
or failing themselves.  gfs2 one didn't.

Fixes: 6d4ade986f (GFS2: Add atomic_open support)
Cc: stable@kernel.org # v3.11
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-03-12 18:21:24 -04:00
Bob Peterson
490031281d gfs2: Additional information when gfs2_ail1_flush withdraws
Before this patch, if gfs2_ail1_flush gets an error from function
gfs2_ail1_start_one (which comes indirectly from generic_writepages)
the file system is withdrawn, but without any explanation why.

This patch adds an error message if gfs2_ail1_flush gets an error
from gfs2_ail1_start_one.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2020-03-06 10:15:03 -06:00
Bob Peterson
cc44457f16 gfs2: leaf_dealloc needs to allocate one more revoke
Function leaf_dealloc was not allocating enough journal space for
revokes. Before, it allocated 'l_blocks' revokes, but it needs one
more for the revoke of the dinode that is modified. This patch adds
the needed revoke entry to function leaf_dealloc.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2020-02-27 07:53:18 -06:00
Bob Peterson
c9ebc4b737 gfs2: allow journal replay to hold sd_log_flush_lock
Before this patch, journal replays could stomp on log flushes
and each other because both log flushes and journal replays used
the same sd_log_bio. Function gfs2_log_flush prevents other log
flushes from interfering by taking the sd_log_flush_lock rwsem
during the flush. However, it does not protect against journal
replays. This patch allows the journal replay to take the same
sd_log_flush_lock rwsem so use of the sd_log_bio is not stomped.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2020-02-27 07:53:18 -06:00
Bob Peterson
019dd669bd gfs2: don't allow releasepage to free bd still used for revokes
Before this patch, function gfs2_releasepage would free any bd
elements that had been used for the page being released. However,
those bd elements may still be queued to the sd_log_revokes list,
in which case we cannot free them until the revoke has been issued.

This patch adds additional checks for bds that are still being
used for revokes.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2020-02-27 07:53:18 -06:00
Bob Peterson
ca399c96e9 gfs2: flesh out delayed withdraw for gfs2_log_flush
Function gfs2_log_flush() had a few places where it tried to withdraw
from the file system when errors were encountered. The problem is,
it should delay those withdraws until the log flush lock is no longer
held.

This patch creates a new function just for delayed withdraws for
situations like this. If errors=panic was specified on mount, we
still want to do it the old fashioned way because the panic it does
not help to delay in that situation.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-02-27 07:53:18 -06:00
Bob Peterson
1c634f94c3 gfs2: Do proper error checking for go_sync family of glops functions
Before this patch, function do_xmote would try to sync out the glock
dirty data by calling the appropriate glops function XXX_go_sync()
but it did not check for a good return code. If the sync was not
possible due to an io error or whatever, do_xmote would continue on
and call go_inval and release the glock to other cluster nodes.
When those nodes go to replay the journal, they may already be holding
glocks for the journal records that should have been synced, but were
not due to the ignored error.

This patch introduces proper error code checking to the go_sync
family of glops functions.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-02-27 07:53:18 -06:00
Bob Peterson
df5db5f9ee gfs2: Don't demote a glock until its revokes are written
Before this patch, run_queue would demote glocks based on whether
there are any more holders. But if the glock has pending revokes that
haven't been written to the media, giving up the glock might end in
file system corruption if the revokes never get written due to
io errors, node crashes and fences, etc. In that case, another node
will replay the metadata blocks associated with the glock, but
because the revoke was never written, it could replay that block
even though the glock had since been granted to another node who
might have made changes.

This patch changes the logic in run_queue so that it never demotes
a glock until its count of pending revokes reaches zero.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-02-27 07:53:18 -06:00
Bob Peterson
2ca0c2fbf3 gfs2: drain the ail2 list after io errors
Before this patch, gfs2_logd continually tried to flush its journal
log, after the file system is withdrawn. We don't want to write anything
to the journal, lest we add corruption. Best course of action is to
drain the ail1 into the ail2 list (via gfs2_ail1_empty) then drain the
ail2 list with a new function, ail2_drain.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-02-27 07:53:18 -06:00
Bob Peterson
b1676cbb11 gfs2: Withdraw in gfs2_ail1_flush if write_cache_pages fails
Before this patch, function gfs2_ail1_start_one would return any
errors it received from write_cache_pages (except -EBUSY) but it did
not withdraw. Since function gfs2_ail1_flush just checks for the bad
return code and loops, the loop might potentially never end.
This patch adds some logic to allow it to exit the loop and withdraw
properly when errors are received from write_cache_pages.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-02-27 07:53:18 -06:00
Bob Peterson
9ff7828935 gfs2: Do log_flush in gfs2_ail_empty_gl even if ail list is empty
Before this patch, if gfs2_ail_empty_gl saw there was nothing on
the ail list, it would return and not flush the log. The problem
is that there could still be a revoke for the rgrp sitting on the
sd_log_le_revoke list that's been recently taken off the ail list.
But that revoke still needs to be written, and the rgrp_go_inval
still needs to call log_flush_wait to ensure the revokes are all
properly written to the journal before we relinquish control of
the glock to another node. If we give the glock to another node
before we have this knowledge, the node might crash and its journal
replayed, in which case the missing revoke would allow the journal
replay to replay the rgrp over top of the rgrp we already gave to
another node, thus overwriting its changes and corrupting the
file system.

This patch makes gfs2_ail_empty_gl still call gfs2_log_flush rather
than returning.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-02-27 07:53:18 -06:00
Bob Peterson
d93ae386ef gfs2: Check for log write errors before telling dlm to unlock
Before this patch, function do_xmote just assumed all the writes
submitted to the journal were finished and successful, and it
called the go_unlock function to release the dlm lock. But if
they're not, and a revoke failed to make its way to the journal,
a journal replay on another node will cause corruption if we
let the go_inval function continue and tell dlm to release the
glock to another node. This patch adds a couple checks for errors
in do_xmote after the calls to go_sync and go_inval. If an error
is found, we cannot withdraw yet, because the withdraw itself
uses glocks to make the file system read-only. Instead, we flag
the error. Later, asserts should cause another node to replay
the journal before continuing, thus protecting rgrp and dinode
glocks and maintaining the integrity of the metadata. Note that
we only need to do this for journaled glocks. System glocks
should be able to progress even under withdrawn conditions.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-02-27 07:53:18 -06:00
Bob Peterson
f05b86db31 gfs2: Prepare to withdraw as soon as an IO error occurs in log write
Before this patch, function gfs2_end_log_write would detect any IO
errors writing to the journal and put out an appropriate message,
but it never set a withdrawing condition. Eventually, the log daemon
would see the error and determine it was time to withdraw, but in
the meantime, other processes could continue running as if nothing
bad ever happened. The biggest consequence is that __gfs2_glock_put
would BUG() when it saw that there were still unwritten items.

This patch sets the WITHDRAWING status as soon as an IO error is
detected, and that way, the BUG will be avoided so the file system
can be properly withdrawn and unmounted.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-02-27 07:53:18 -06:00
Bob Peterson
5e4c7632aa gfs2: Issue revokes more intelligently
Before this patch, function gfs2_write_revokes would call
gfs2_ail1_empty, then traverse the sd_ail1_list looking for
transactions that had bds which were no longer queued to a glock.
And if it found some, it would try to issue revokes for them, up to
a predetermined maximum. There were two problems with how it did
this. First was the fact that gfs2_ail1_empty moves transactions
which have nothing remaining on the ail1 list from the sd_ail1_list
to the sd_ail2_list, thus making its traversal of sd_ail1_list
miss them completely, and therefore, never issue revokes for them.
Second was the fact that there were three traversals (or partial
traversals) of the sd_ail1_list, each of which took and then
released the sd_ail_lock lock: First inside gfs2_ail1_empty,
second to determine if there are any revokes to be issued, and
third to actually issue them. All this taking and releasing of the
sd_ail_lock meant other processes could modify the lists and the
conditions in which we're working.

This patch simplies the whole process by adding a new parameter
to function gfs2_ail1_empty, max_revokes. For normal calls, this
is passed in as 0, meaning we don't want to issue any revokes.
For function gfs2_write_revokes, we pass in the maximum number
of revokes we can, thus allowing gfs2_ail1_empty to add the
revokes where needed. This simplies the code, allows for a single
holding of the sd_ail_lock, and allows gfs2_ail1_empty to add
revokes for all the necessary bd items without missing any.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-02-27 07:53:18 -06:00
Bob Peterson
7d9f924958 gfs2: Add verbose option to check_journal_clean
Before this patch, function check_journal_clean would give messages
related to journal recovery. That's fine for mount time, but when a
node withdraws and forces replay that way, we don't want all those
distracting and misleading messages. This patch adds a new parameter
to make those messages optional.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-02-27 07:53:17 -06:00
Bob Peterson
33dbd1e41a gfs2: fix infinite loop when checking ail item count before go_inval
Before this patch, the rgrp_go_inval and inode_go_inval functions each
checked if there were any items left on the ail count (by way of a
count), and if so, did a withdraw. But the withdraw code now uses
glocks when changing the file system to read-only status. So we can
not have glock functions withdrawing or a hang will likely result:
The glocks can't be serviced by the work_func if the work_func is
busy doing its own withdraw.

This patch removes the checks from the go_inval functions and adds
a centralized check in do_xmote to warn about the problem and not
withdraw, but flag the error so it's eventually caught when the logd
daemon eventually runs.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-02-27 07:53:17 -06:00