linux.git/fs/gfs2, branch v5.7

gfs2: Even more gfs2_find_jhead fixes

2020-05-29T15:00:24+00:00

Fix several issues in the previous gfs2_find_jhead fix:
* When updating @blocks_submitted, @block refers to the first block block not
  submitted yet, not the last block submitted, so fix an off-by-one error.
* We want to ensure that @blocks_submitted is far enough ahead of @blocks_read
  to guarantee that there is in-flight I/O.  Otherwise, we'll eventually end up
  waiting for pages that haven't been submitted, yet.
* It's much easier to compare the number of blocks added with the number of
  blocks submitted to limit the maximum bio size.
* Even with bio chaining, we can keep adding blocks until we reach the maximum
  bio size, as long as we stop at a page boundary.  This simplifies the logic.

Signed-off-by: Andreas Gruenbacher 
Reviewed-by: Bob Peterson

Revert "gfs2: Don't demote a glock until its revokes are written"

2020-05-08T20:01:25+00:00

This reverts commit df5db5f9ee112e76b5202fbc331f990a0fc316d6.

This patch fixes a regression: patch df5db5f9ee112 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

gfs2: If go_sync returns error, withdraw but skip invalidate

2020-05-08T20:00:07+00:00

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 
Signed-off-by: Andreas Gruenbacher

gfs2: Grab glock reference sooner in gfs2_add_revoke

2020-05-08T16:49:04+00:00

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 
Signed-off-by: Bob Peterson

gfs2: don't call quota_unhold if quotas are not locked

2020-05-08T16:49:04+00:00

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 
Signed-off-by: Andreas Gruenbacher

gfs2: move privileged user check to gfs2_quota_lock_check

2020-05-08T16:47:58+00:00

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 
Signed-off-by: Andreas Gruenbacher

gfs2: remove check for quotas on in gfs2_quota_check

2020-05-08T16:47:39+00:00

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 
Signed-off-by: Andreas Gruenbacher

gfs2: Change BUG_ON to an assert_withdraw in gfs2_quota_change

2020-05-08T16:45:12+00:00

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 
Signed-off-by: Andreas Gruenbacher

gfs2: Fix problems regarding gfs2_qa_get and _put

2020-05-08T16:45:11+00:00

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 
Signed-off-by: Andreas Gruenbacher

gfs2: More gfs2_find_jhead fixes

2020-05-08T13:15:12+00:00

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 07173c3ec276 ("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: f4686c26ecc3 ("gfs2: read journal in large chunks")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Andreas Gruenbacher 
Signed-off-by: Bob Peterson