Using list_move_tail() instead of list_del() + list_add_tail().
Reported-by: NHulk Robot <hulkci@huawei.com>
Signed-off-by: NBaokun Li <libaokun1@huawei.com>
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

Commit 88b631cb ("gfs2: convert to fileattr") changed the argument list
without updating the description.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

This reverts commit b7f55d92.

As explained by Linus in [*], write faults on a mmap region are reads
from a filesysten point of view, so taking the inode glock exclusively
on write faults is incorrect.

Instead, when a page is marked writable, the .page_mkwrite vm operation
will be called, which is where the exclusive lock taking needs to
happen.  I got this wrong because of a broken test case that made me
believe .page_mkwrite isn't getting called when it actually is.

[*] https://lore.kernel.org/lkml/CAHk-=wj8EWr_D65i4oRSj2FTbrc6RdNydNNCGxeabRnwtoU=3Q@mail.gmail.com/Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

The GLF_LRU flag is checked under lru_lock in gfs2_glock_remove_from_lru() to
remove the glock from the lru list in __gfs2_glock_put().

On the shrink scan path, the same flag is cleared under lru_lock but because
of cond_resched_lock(&lru_lock) in gfs2_dispose_glock_lru(), progress on the
put side can be made without deleting the glock from the lru list.

Keep GLF_LRU across the race window opened by cond_resched_lock(&lru_lock) to
ensure correct behavior on both sides - clear GLF_LRU after list_del under
lru_lock.
Reported-by: Nsyzbot <syzbot+34ba7ddbf3021981a228@syzkaller.appspotmail.com>
Signed-off-by: NHillf Danton <hdanton@sina.com>
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

When a write fault occurs, we need to take the inode glock of the underlying
inode in exclusive mode.  Otherwise, there's no guarantee that the dirty page
will be written back to disk.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

Before this patch, the system ail lists were cleaned up if the logd
process withdrew, but on other withdraws, they were not cleaned up.
This included the cleaning up of the revokes as well.

This patch reorganizes things a bit so that all withdraws (not just logd)
clean up the ail lists, including any pending revokes.
Signed-off-by: NBob Peterson <rpeterso@redhat.com>
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

Before this patch, gfs2 would deadlock because of the following
sequence during mount:

mount
   gfs2_fill_super
      gfs2_make_fs_rw <--- Detects IO error with glock
         kthread_stop(sdp->sd_quotad_process);
            <--- Blocked waiting for quotad to finish

logd
   Detects IO error and the need to withdraw
   calls gfs2_withdraw
      gfs2_make_fs_ro
         kthread_stop(sdp->sd_quotad_process);
            <--- Blocked waiting for quotad to finish

gfs2_quotad
   gfs2_statfs_sync
      gfs2_glock_wait <---- Blocked waiting for statfs glock to be granted

glock_work_func
   do_xmote <---Detects IO error, can't release glock: blocked on withdraw
      glops->go_inval
      glock_blocked_by_withdraw
         requeue glock work & exit <--- work requeued, blocked by withdraw

This patch makes a special exception for the statfs system inode glock,
which allows the statfs glock UNLOCK to proceed normally. That allows the
quotad daemon to exit during the withdraw, which allows the logd daemon
to exit during the withdraw, which allows the mount to exit.
Signed-off-by: NBob Peterson <rpeterso@redhat.com>
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

Before this patch, in the unlikely event that gfs2_glock_dq encountered
a withdraw, it would do a wait_on_bit to wait for its journal to be
recovered, but it never released the glock's spin_lock, which caused a
scheduling-while-atomic error.

This patch unlocks the lockref spin_lock before waiting for recovery.

Fixes: 601ef0d5 ("gfs2: Force withdraw to replay journals and wait for it to finish")
Cc: stable@vger.kernel.org # v5.7+
Reported-by: NAlexander Aring <aahringo@redhat.com>
Signed-off-by: NBob Peterson <rpeterso@redhat.com>
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

Patch 4a378d8a added a new check for I_NEW inodes, but unfortunately
it used the wrong variable, i_flags. This caused GFS2 to withdraw when
gfs2_lookup_by_inum needed to refresh an I_NEW inode. This patch switches
to use the correct variable, i_state.

Fixes: 4a378d8a ("gfs2: be careful with inode refresh")
Signed-off-by: NBob Peterson <rpeterso@redhat.com>
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

When a direct I/O write falls entirely and falls back to buffered I/O and the
buffered I/O fails, the write failed with return value 0 instead of the error
number reported by the buffered I/O. Fix that.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

Patch series "Remove nrexceptional tracking", v2.

We actually use nrexceptional for very little these days.  It's a minor
pain to keep in sync with nrpages, but the pain becomes much bigger with
the THP patches because we don't know how many indices a shadow entry
occupies.  It's easier to just remove it than keep it accurate.

Also, we save 8 bytes per inode which is nothing to sneeze at; on my
laptop, it would improve shmem_inode_cache from 22 to 23 objects per
16kB, and inode_cache from 26 to 27 objects.  Combined, that saves
a megabyte of memory from a combined usage of 25MB for both caches.
Unfortunately, ext4 doesn't cross a magic boundary, so it doesn't save
any memory for ext4.

This patch (of 4):

Instead of checking the two counters (nrpages and nrexceptional), we can
just check whether i_pages is empty.

Link: https://lkml.kernel.org/r/20201026151849.24232-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20201026151849.24232-2-willy@infradead.orgSigned-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: NVishal Verma <vishal.l.verma@intel.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In preparation to enable -Wimplicit-fallthrough for Clang, fix multiple
warnings by explicitly adding multiple goto statements instead of just
letting the code fall through to the next case.

Link: https://github.com/KSPP/linux/issues/115Signed-off-by: NGustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

Use the fileattr API to let the VFS handle locking, permission checking and
conversion.
Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>
Cc: Andreas Gruenbacher <agruenba@redhat.com>

Building the kernel with W=1 results in a number of kernel-doc warnings
like incorrect function names and parameter descriptions.  Fix those,
mostly by adding missing parameter descriptions, removing left-over
descriptions, and demoting some less important kernel-doc comments into
regular comments.

Originally proposed by Lee Jones; improved and combined into a single
patch by Andreas.
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

list_sort() internally casts the comparison function passed to it
to a different type with constant struct list_head pointers, and
uses this pointer to call the functions, which trips indirect call
Control-Flow Integrity (CFI) checking.

Instead of removing the consts, this change defines the
list_cmp_func_t type and changes the comparison function types of
all list_sort() callers to use const pointers, thus avoiding type
mismatches.
Suggested-by: NNick Desaulniers <ndesaulniers@google.com>
Signed-off-by: NSami Tolvanen <samitolvanen@google.com>
Reviewed-by: NNick Desaulniers <ndesaulniers@google.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NKees Cook <keescook@chromium.org>
Tested-by: NNick Desaulniers <ndesaulniers@google.com>
Tested-by: NNathan Chancellor <nathan@kernel.org>
Signed-off-by: NKees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210408182843.1754385-10-samitolvanen@google.com

This function is only used in inode.c.
Signed-off-by: NAndreas 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: NBob Peterson <rpeterso@redhat.com>
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

In gfs2_rbm_find, rs is always NULL when minext is NULL, so
gfs2_reservation_check_and_update will never be called on a NULL minext.
This isn't innediately obvious though, so also check for a NULL minext
for better code readability.
Reported-by: Nkernel test robot <lkp@intel.com>
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

Instead of only supporting GFS2_METATYPE_DI and GFS2_METATYPE_IN blocks,
make the block type a parameter of gfs2_meta_indirect_buffer and rename
the function to gfs2_meta_buffer.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

We don't need two very similar functions for mapping logical blocks to physical
blocks.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

Convert gfs2_extent_map to iomap and split it into gfs2_get_extent and
gfs2_alloc_extent.  Instead of hardcoding the extent size, pass it in
via the extlen parameter.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

Rename the current gfs2_iomap_get and gfs2_iomap_alloc functions to __*.
Add a new gfs2_iomap_get helper that doesn't expose struct metapath.
Rename gfs2_iomap_get_alloc to gfs2_iomap_alloc.  Use the new helpers
where they make sense.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

This patch simply fixes a bunch of function parameter comments
in dir.c that were reported by the kernel test robot.
Reported-by: Nkernel test robot <lkp@intel.com>
Signed-off-by: NBob Peterson <rpeterso@redhat.com>
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

The only glock that uses go_xmote_bh glops function is the freeze glock
which uses freeze_go_xmote_bh. It does not use its gh parameter, so
this patch eliminates the unneeded parameter.
Signed-off-by: NBob Peterson <rpeterso@redhat.com>
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

Before this patch, function gfs2_getbuf would create empty buffers when
it was given the NO_CREATE directive from gfs2_journal_wipe. This is a
waste of time: the buffer_head is only used by gfs2_remove_from_journal
to determine if the buffer is pinned (which it won't be if it's newly
created) and if there's an associated bd element (same story).
This patch removes the useless buffer assignment.
Signed-off-by: NBob Peterson <rpeterso@redhat.com>
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

Before this patch, gfs2's freeze function failed to report an error
when the target file system was already frozen as it should (and as
generic vfs function freeze_super does. Similarly, gfs2's thaw function
failed to report an error when trying to thaw a file system that is not
frozen, as vfs function thaw_super does. The errors were checked, but
it always returned a 0 return code.

This patch adds the missing error return codes to gfs2 freeze and thaw.
Signed-off-by: NBob Peterson <rpeterso@redhat.com>
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

Interrupting mount with ^C quickly enough can cause the kthread_run()
calls in gfs2's init_threads() to fail and the error path leads to a
deadlock on the s_umount rwsem. The abridged chain of events is:

  [mount path]
  get_tree_bdev()
    sget_fc()
      alloc_super()
        down_write_nested(&s->s_umount, SINGLE_DEPTH_NESTING); [acquired]
    gfs2_fill_super()
      gfs2_make_fs_rw()
        init_threads()
          kthread_run()
            ( Interrupted )
      [Error path]
      gfs2_gl_hash_clear()
        flush_workqueue(glock_workqueue)
          wait_for_completion()

  [workqueue context]
  glock_work_func()
    run_queue()
      do_xmote()
        freeze_go_sync()
          freeze_super()
            down_write(&sb->s_umount) [deadlock]

In freeze_go_sync() there is a gfs2_withdrawn() check that we can use to
make sure freeze_super() is not called in the error path, so add a
gfs2_withdraw_delayed() call when init_threads() fails.

Ref: https://bugzilla.kernel.org/show_bug.cgi?id=212231Reported-by: NAlexander Aring <aahringo@redhat.com>
Signed-off-by: NAndrew Price <anprice@redhat.com>
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

1) gfs2_dinode_in() should *not* touch ->i_rdev on live inodes; even
"zero and immediately reread the same value from dinode" is broken -
have it overlap with ->release() of char device and you can get all
kinds of bogus behaviour.

2) mismatch on inode type on live inodes should be treated as fs
corruption rather than blindly setting ->i_mode.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Patch fe3e3976 ("gfs2: Rework the log space allocation logic")
changed gfs2_log_flush to reserve a set of journal blocks in case no
transaction is active.  However, gfs2_log_flush also gets called in
cases where we don't have an active journal, for example, for spectator
mounts.  In that case, trying to reserve blocks would sleep forever, but
we want gfs2_log_flush to be a no-op instead.

Fixes: fe3e3976 ("gfs2: Rework the log space allocation logic")
Signed-off-by: NBob Peterson <rpeterso@redhat.com>
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

Before this patch, function signal_our_withdraw referenced the journal
inode immediately. But corrupt file systems may have some invalid
journals, in which case our attempt to read it in will withdraw and the
resulting signal_our_withdraw would dereference the NULL value.

This patch adds a check to signal_our_withdraw so that if the journal
has not yet been initialized, it simply returns and does the old-style
withdraw.

Thanks, Andy Price, for his analysis.

Reported-by: syzbot+50a8a9cf8127f2c6f5df@syzkaller.appspotmail.com
Fixes: 601ef0d5 ("gfs2: Force withdraw to replay journals and wait for it to finish")
Signed-off-by: NBob Peterson <rpeterso@redhat.com>
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

Ever since the addition of multipage bio_vecs BIO_MAX_PAGES has been
horribly confusingly misnamed.  Rename it to BIO_MAX_VECS to stop
confusing users of the bio API.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20210311110137.1132391-2-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

This patch adds code to function trans_drain to remove drained
bd elements from the ail lists, if queued, before freeing the bd.
If we don't remove the bd from the ail, function ail_drain will
try to reference the bd after it has been freed by trans_drain.

Thanks to Andy Price for his analysis of the problem.
Reported-by: NAndy Price <anprice@redhat.com>
Signed-off-by: NBob Peterson <rpeterso@redhat.com>
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

It fixes the following warning detected by coccinelle:
./fs/gfs2/super.c:592:5-10: Unneeded variable: "error". Return "0" on
line 628
Reported-by: NAbaci Robot <abaci@linux.alibaba.com>
Signed-off-by: NYang Li <yang.lee@linux.alibaba.com>
Signed-off-by: NBob Peterson <rpeterso@redhat.com>
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

In gfs2_ail1_flush, we're using I/O plugging to give the block layer a
better chance of merging I/O requests.  If we're too aggressive here, we
can end up waiting on I/O to complete while still plugged.  Fix that in
a way similar to writeback_sb_inodes, except that we can't use
blk_flush_plug because blk_flush_plug_list is not exported.
Signed-off-by: NBob Peterson <rpeterso@redhat.com>
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

several instances creeped back into the tree...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

In the log, revokes are stored as a revoke descriptor (struct
gfs2_log_descriptor), followed by zero or more additional revoke blocks
(struct gfs2_meta_header).  On filesystems with a blocksize of 4k, the
revoke descriptor contains up to 503 revokes, and the metadata blocks
contain up to 509 revokes each.  We've so far been reserving space for
revokes in transactions in block granularity, so a lot more space than
necessary was being allocated and then released again.

This patch switches to assigning revokes to transactions individually
instead.  Initially, space for the revoke descriptor is reserved and
handed out to transactions.  When more revokes than that are reserved,
additional revoke blocks are added.  When the log is flushed, the space
for the additional revoke blocks is released, but we keep the space for
the revoke descriptor block allocated.

Transactions may still reserve more revokes than they will actually need
in the end, but now we won't overshoot the target as much, and by only
returning the space for excess revokes at log flush time, we further
reduce the amount of contention between processes.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

The current log space allocation logic is hard to understand or extend.
The principle it that when the log is flushed, we may or may not have a
transaction active that has space allocated in the log.  To deal with
that, we set aside a magical number of blocks to be used in case we
don't have an active transaction.  It isn't clear that the pool will
always be big enough.  In addition, we can't return unused log space at
the end of a transaction, so the number of blocks allocated must exactly
match the number of blocks used.

Simplify this as follows:
 * When transactions are allocated or merged, always reserve enough
   blocks to flush the transaction (err on the safe side).
 * In gfs2_log_flush, return any allocated blocks that haven't been used.
 * Maintain a pool of spare blocks big enough to do one log flush, as
   before.
 * In gfs2_log_flush, when we have no active transaction, allocate a
   suitable number of blocks.  For that, use the spare pool when
   called from logd, and leave the pool alone otherwise.  This means
   that when the log is almost full, logd will still be able to do one
   more log flush, which will result in more log space becoming
   available.

This will make the log space allocator code easier to work with in
the future.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

No functional change.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

This patch takes advantage of the new glock holder sharing feature for
resource groups.  We have already introduced local resource group
locking in a previous patch, so competing accesses of local processes
are already under control.
Signed-off-by: NBob Peterson <rpeterso@redhat.com>
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>