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>
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>
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>
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>
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>
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>
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 813e0c46c9 ("GFS2: Fix "truncate in progress" hang").
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
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>
Since commit 1fc05c8d84 ("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>
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>
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>
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>
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>
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>
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>
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>
The gfs2 evict code tries to upgrade the iopen glock from SH to EX. If
the attempt to upgrade times out, gfs2 needs to tell dlm to cancel the
lock request or it can deadlock. We also need to wake up the process
waiting for the lock when dlm sends its AST back to gfs2.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
It turns out that the might_sleep() call that commit 660a6126f8 adds
is triggering occasional data corruption in testing. We're not sure
about the root cause yet, but since this commit was added as a debugging
aid only, revert it for now.
This reverts commit 660a6126f8.
Fixes: 660a6126f8 ("gfs2: check context in gfs2_glock_put")
Cc: stable@vger.kernel.org # v5.16+
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
The description of gfs2_instantiate accidentally lists a glock argument,
but the function takes a glock holder.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
The function name in the kernel-doc comment wasn't updated when the
function was renamed.
Fixes: b016d9a84a ("gfs2: Save ip from gfs2_glock_nq_init")
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
When we mock up a temporary holder in gfs2_glock_cb to demote weak holders in
response to a remote locking conflict, we don't set the HIF_HOLDER flag. This
causes function may_grant to BUG. Fix by setting the missing HIF_HOLDER flag
in the mock glock holder.
In addition, define the mock glock holder where it is used.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Function demote_incompat_holders iterates over the list of glock holders
with list_for_each_entry, and it then sometimes removes the current
holder from the list. This will get the loop stuck; we must use
list_for_each_entry_safe instead.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Replace test_bit() + set_bit() with test_and_set_bit() where we need an atomic
operation. Use clear_and_wake_up_bit() instead of open coding it.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Add a might_sleep call into gfs2_glock_put which can sleep in DLM when
the last reference is released. This will show problems earlier, and
not only when the last reference is put.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
So far, glock_hash_walk took a reference on each glock it iterated over, and it
was the examiner's responsibility to drop those references. Dropping the final
reference to a glock can sleep and the examiners are called in a RCU critical
section with spin locks held, so examiners that didn't need the extra reference
had to drop it asynchronously via gfs2_glock_queue_put or similar. This wasn't
done correctly in thaw_glock which did call gfs2_glock_put, and not at all in
dump_glock_func.
Change glock_hash_walk to not take glock references at all. That way, the
examiners that don't need them won't have to bother with slow asynchronous
puts, and the examiners that do need references can take them themselves.
Reported-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
In gfs2_inode_lookup and gfs2_create_inode, we're calling
gfs2_cancel_delete_work which currently cancels any remote delete work
(delete_work_func) synchronously. This means that if the work is
currently running, it will wait for it to finish. We're doing this to
pevent a previous instance of an inode from having any influence on the
next instance.
However, delete_work_func uses gfs2_inode_lookup internally, and we can
end up in a deadlock when delete_work_func gets interrupted at the wrong
time. For example,
(1) An inode's iopen glock has delete work queued, but the inode
itself has been evicted from the inode cache.
(2) The delete work is preempted before reaching gfs2_inode_lookup.
(3) Another process recreates the inode (gfs2_create_inode). It tries
to cancel any outstanding delete work, which blocks waiting for
the ongoing delete work to finish.
(4) The delete work calls gfs2_inode_lookup, which blocks waiting for
gfs2_create_inode to instantiate and unlock the new inode =>
deadlock.
It turns out that when the delete work notices that its inode has been
re-instantiated, it will do nothing. This means that it's safe to
cancel the delete work asynchronously. This prevents the kind of
deadlock described above.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Before this patch, when a glock was locked, the very first holder on the
queue would unlock the lockref and call the go_instantiate glops function
(if one existed), unless GL_SKIP was specified. When we introduced the new
node-scope concept, we allowed multiple holders to lock glocks in EX mode
and share the lock.
But node-scope introduced a new problem: if the first holder has GL_SKIP
and the next one does NOT, since it is not the first holder on the queue,
the go_instantiate op was not called. Eventually the GL_SKIP holder may
call the instantiate sub-function (e.g. gfs2_rgrp_bh_get) but there was
still a window of time in which another non-GL_SKIP holder assumes the
instantiate function had been called by the first holder. In the case of
rgrp glocks, this led to a NULL pointer dereference on the buffer_heads.
This patch tries to fix the problem by introducing two new glock flags:
GLF_INSTANTIATE_NEEDED, which keeps track of when the instantiate function
needs to be called to "fill in" or "read in" the object before it is
referenced.
GLF_INSTANTIATE_IN_PROG which is used to determine when a process is
in the process of reading in the object. Whenever a function needs to
reference the object, it checks the GLF_INSTANTIATE_NEEDED flag, and if
set, it sets GLF_INSTANTIATE_IN_PROG and calls the glops "go_instantiate"
function.
As before, the gl_lockref spin_lock is unlocked during the IO operation,
which may take a relatively long amount of time to complete. While
unlocked, if another process determines go_instantiate is still needed,
it sees GLF_INSTANTIATE_IN_PROG is set, and waits for the go_instantiate
glop operation to be completed. Once GLF_INSTANTIATE_IN_PROG is cleared,
it needs to check GLF_INSTANTIATE_NEEDED again because the other process's
go_instantiate operation may not have been successful.
Functions that previously called the instantiate sub-functions now call
directly into gfs2_instantiate so the new bits are managed properly.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Before this patch, function do_promote had a section of code that did
the actual instantiation. This patch splits that off into its own
function, gfs2_instantiate, which prepares us for the next patch that
will use that function.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
This patch further simplifies function do_promote by eliminating some
redundant code in favor of using a lock_released flag. This is just
prep work for a future patch.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
This patch simply re-factors function do_promote to reduce the indents.
The logic should be unchanged. This makes future patches more readable.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Remove the 'first' argument of trace_gfs2_promote: with GL_SKIP, the
'first' holder isn't the one that instantiates the glock
(gl_instantiate), which is what the 'first' flag was apparently supposed
to indicate.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Before this patch, the go_lock glock operations (glops) did not do
any actual locking. They were used to instantiate objects, like reading
in dinodes and rgrps from the media.
This patch renames the functions to go_instantiate for clarity.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Before this patch, when a glock was locked by function gfs2_glock_nq_init,
it initialized the holder gh_ip (return address) as gfs2_glock_nq_init.
That made it extremely difficult to track down problems because many
functions call gfs2_glock_nq_init. This patch changes the function so
that it saves gh_ip from the caller of gfs2_glock_nq_init, which makes
it easy to backtrack which holder took the lock.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Before this patch, each individual "go_lock" glock operation (glop)
checked the GL_SKIP flag, and if set, would skip further processing.
This patch changes the logic so the go_lock caller, function go_promote,
checks the GL_SKIP flag before calling the go_lock op in the first place.
This avoids having to unnecessarily unlock gl_lockref.lock only to
re-lock it again.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Somehow, the GL_SKIP flag was missed when dumping glock holders.
This patch adds it to function hflags2str. I added it at the end because
I wanted Holder and Skip flags together to read "Hs" rather than "sH"
to avoid confusion with "Shared" ("SH") holder state.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
This patch introduces a new HIF_MAY_DEMOTE flag and infrastructure that
will allow glocks to be demoted automatically on locking conflicts.
When a locking request comes in that isn't compatible with the locking
state of an active holder and that holder has the HIF_MAY_DEMOTE flag
set, the holder will be demoted before the incoming locking request is
granted.
Note that this mechanism demotes active holders (with the HIF_HOLDER
flag set), while before we were only demoting glocks without any active
holders. This allows processes to keep hold of locks that may form a
cyclic locking dependency; the core glock logic will then break those
dependencies in case a conflicting locking request occurs. We'll use
this to avoid giving up the inode glock proactively before faulting in
pages.
Processes that allow a glock holder to be taken away indicate this by
calling gfs2_holder_allow_demote(), which sets the HIF_MAY_DEMOTE flag.
Later, they call gfs2_holder_disallow_demote() to clear the flag again,
and then they check if their holder is still queued: if it is, they are
still holding the glock; if it isn't, they can re-acquire the glock (or
abort).
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Pass the first current glock holder into function may_grant and
deobfuscate the logic there.
While at it, switch from BUG_ON to GLOCK_BUG_ON in may_grant. To make
that build cleanly, de-constify the may_grant arguments.
We're now using function find_first_holder in do_promote, so move the
function's definition above do_promote.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
In function gfs2_glock_dq, it checks to see if this is the fast path.
Before this patch, it checked both "find_first_holder(gl) == NULL" and
list_empty(&gl->gl_holders), which is redundant. If gl_holders is empty
then find_first_holder must return NULL. This patch removes the
redundancy.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Using list_move_tail() instead of list_del() + list_add_tail().
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Signed-off-by: Andreas 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: syzbot <syzbot+34ba7ddbf3021981a228@syzkaller.appspotmail.com>
Signed-off-by: Hillf Danton <hdanton@sina.com>
Signed-off-by: Andreas 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: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas 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: 601ef0d52e ("gfs2: Force withdraw to replay journals and wait for it to finish")
Cc: stable@vger.kernel.org # v5.7+
Reported-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas 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.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Vishal Verma <vishal.l.verma@intel.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- Fix some compiler and kernel-doc warnings.
- Various minor cleanups and optimizations.
- Add a new sysfs gfs2 status file with some filesystem wide
information.
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Merge tag 'gfs2-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2
Pull gfs2 updates from Andreas Gruenbacher:
- Fix some compiler and kernel-doc warnings
- Various minor cleanups and optimizations
- Add a new sysfs gfs2 status file with some filesystem wide
information
* tag 'gfs2-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
gfs2: Fix fall-through warnings for Clang
gfs2: Fix a number of kernel-doc warnings
gfs2: Make gfs2_setattr_simple static
gfs2: Add new sysfs file for gfs2 status
gfs2: Silence possible null pointer dereference warning
gfs2: Turn gfs2_meta_indirect_buffer into gfs2_meta_buffer
gfs2: Replace gfs2_lblk_to_dblk with gfs2_get_extent
gfs2: Turn gfs2_extent_map into gfs2_{get,alloc}_extent
gfs2: Add new gfs2_iomap_get helper
gfs2: Remove unused variable sb_format
gfs2: Fix dir.c function parameter descriptions
gfs2: Eliminate gh parameter from go_xmote_bh func
gfs2: don't create empty buffers for NO_CREATE
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: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Andreas 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: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210408182843.1754385-10-samitolvanen@google.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: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Introduce a new LM_FLAG_NODE_SCOPE glock holder flag: when taking a
glock in LM_ST_EXCLUSIVE (EX) mode and with the LM_FLAG_NODE_SCOPE flag
set, the exclusive lock is shared among all local processes who are
holding the glock in EX mode and have the LM_FLAG_NODE_SCOPE flag set.
From the point of view of other nodes, the lock is still held
exclusively.
A future patch will start using this flag to improve performance with
rgrp sharing.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Since commit a0e3cc65fa ("gfs2: Turn gl_delete into a delayed work"), we're
cancelling any pending delete work of an iopen glock before attaching a new
inode to that glock in gfs2_create_inode. This means that delete_work_func can
no longer be queued or running when attaching the iopen glock to the new inode,
and we can revert commit a4923865ea ("GFS2: Prevent delete work from
occurring on glocks used for create"), which tried to achieve the same but in a
racy way.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
This patch introduce a new globs attribute to define the subclass of the
glock lockref spinlock. This avoid the following lockdep warning, which
occurs when we lock an inode lock while an iopen lock is held:
============================================
WARNING: possible recursive locking detected
5.10.0-rc3+ #4990 Not tainted
--------------------------------------------
kworker/0:1/12 is trying to acquire lock:
ffff9067d45672d8 (&gl->gl_lockref.lock){+.+.}-{3:3}, at: lockref_get+0x9/0x20
but task is already holding lock:
ffff9067da308588 (&gl->gl_lockref.lock){+.+.}-{3:3}, at: delete_work_func+0x164/0x260
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&gl->gl_lockref.lock);
lock(&gl->gl_lockref.lock);
*** DEADLOCK ***
May be due to missing lock nesting notation
3 locks held by kworker/0:1/12:
#0: ffff9067c1bfdd38 ((wq_completion)delete_workqueue){+.+.}-{0:0}, at: process_one_work+0x1b7/0x540
#1: ffffac594006be70 ((work_completion)(&(&gl->gl_delete)->work)){+.+.}-{0:0}, at: process_one_work+0x1b7/0x540
#2: ffff9067da308588 (&gl->gl_lockref.lock){+.+.}-{3:3}, at: delete_work_func+0x164/0x260
stack backtrace:
CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.10.0-rc3+ #4990
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
Workqueue: delete_workqueue delete_work_func
Call Trace:
dump_stack+0x8b/0xb0
__lock_acquire.cold+0x19e/0x2e3
lock_acquire+0x150/0x410
? lockref_get+0x9/0x20
_raw_spin_lock+0x27/0x40
? lockref_get+0x9/0x20
lockref_get+0x9/0x20
delete_work_func+0x188/0x260
process_one_work+0x237/0x540
worker_thread+0x4d/0x3b0
? process_one_work+0x540/0x540
kthread+0x127/0x140
? __kthread_bind_mask+0x60/0x60
ret_from_fork+0x22/0x30
Suggested-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Commit fc0e38dae6 ("GFS2: Fix glock deallocation race") fixed a
sd_glock_disposal accounting bug by adding a missing atomic_dec
statement, but it failed to wake up sd_glock_wait when that decrement
causes sd_glock_disposal to reach zero. As a consequence,
gfs2_gl_hash_clear can now run into a 10-minute timeout instead of
being woken up. Add the missing wakeup.
Fixes: fc0e38dae6 ("GFS2: Fix glock deallocation race")
Cc: stable@vger.kernel.org # v2.6.39+
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Only initialize gl_delete for iopen glocks, but more importantly, only access
it for iopen glocks in flush_delete_work: flush_delete_work is called for
different types of glocks including rgrp glocks, and those use gl_vm which is
in a union with gl_delete. Without this fix, we'll end up clobbering gl_vm,
which results in general memory corruption.
Fixes: a0e3cc65fa ("gfs2: Turn gl_delete into a delayed work")
Cc: stable@vger.kernel.org # v5.8+
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
The comments before function glock_hash_walk had the wrong name and
an extra parameter. This simply fixes the comments.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Before this patch, glock.c maintained a flag, GLF_QUEUED, which indicated
when a glock had a holder queued. It was only checked for inode glocks,
although set and cleared by all glocks, and it was only used to determine
whether the glock should be held for the minimum hold time before releasing.
The problem is that the flag is not accurate at all. If a process holds
the glock, the flag is set. When they dequeue the glock, it only cleared
the flag in cases when the state actually changed. So if the state doesn't
change, the flag may still be set, even when nothing is queued.
This happens to iopen glocks often: the get held in SH, then the file is
closed, but the glock remains in SH mode.
We don't need a special flag to indicate this: we can simply tell whether
the glock has any items queued to the holders queue. It's a waste of cpu
time to maintain it.
This patch eliminates the flag in favor of simply checking list_empty
on the glock holders.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Before this patch, we were not calling truncate_inode_pages_final for the
address space for glocks, which left the possibility of a leak. We now
take care of the problem instead of complaining, and we do it during
glock tear-down..
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Use DEFINE_SEQ_ATTRIBUTE macro to simplify the code.
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
In gfs2_glock_poke, make sure gfs2_holder_uninit is called on the local
glock holder. Without that, we're leaking a glock and a pid reference.
Fixes: 9e8990dea9 ("gfs2: Smarter iopen glock waiting")
Cc: stable@vger.kernel.org # v5.8+
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Before this patch, three flags were not represented in the glock output.
This patch adds them in:
c - GLF_INODE_CREATING
P - GLF_PENDING_DELETE
x - GLF_FREEING (both f and F are already used)
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
In flush_delete_work, instead of flushing each individual pending
delayed work item, cancel and re-queue them for immediate execution.
The waiting isn't needed here because we're already waiting for all
queued work items to complete in gfs2_flush_delete_work. This makes the
code more efficient, but more importantly, it avoids sleeping during a
rhashtable walk, inside rcu_read_lock().
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
When trying to upgrade the iopen glock from a shared to an exclusive lock in
gfs2_evict_inode, abort the wait if there is contention on the corresponding
inode glock: in that case, the inode must still be in active use on another
node, and we're not guaranteed to get the iopen glock anytime soon.
To make this work even better, when we notice contention on the iopen glock and
we can't evict the corresponsing inode and release the iopen glock immediately,
poke the inode glock. The other node(s) trying to acquire the lock can then
abort instead of timing out.
Thanks to Heinz Mauelshagen for pointing out a locking bug in a previous
version of this patch.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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>
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>
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>
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>
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>
Before this patch, asserts based on glocks did not print the glock with
the error. This patch introduces a new macro, gfs2_glock_assert_withdraw
which first prints the glock, then takes the assert.
This also changes a few glock asserts to the new macro.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
This patch makes the glock dumps in debugfs print the number of pages
(nrpages) for address space glocks. This will aid in debugging.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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>
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>
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>
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>
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>
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>
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>
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>
When a node withdraws from a file system, it often leaves its journal
in an incomplete state. This is especially true when the withdraw is
caused by io errors writing to the journal. Before this patch, a
withdraw would try to write a "shutdown" record to the journal, tell
dlm it's done with the file system, and none of the other nodes
know about the problem. Later, when the problem is fixed and the
withdrawn node is rebooted, it would then discover that its own
journal was incomplete, and replay it. However, replaying it at this
point is almost guaranteed to introduce corruption because the other
nodes are likely to have used affected resource groups that appeared
in the journal since the time of the withdraw. Replaying the journal
later will overwrite any changes made, and not through any fault of
dlm, which was instructed during the withdraw to release those
resources.
This patch makes file system withdraws seen by the entire cluster.
Withdrawing nodes dequeue their journal glock to allow recovery.
The remaining nodes check all the journals to see if they are
clean or in need of replay. They try to replay dirty journals, but
only the journals of withdrawn nodes will be "not busy" and
therefore available for replay.
Until the journal replay is complete, no i/o related glocks may be
given out, to ensure that the replay does not cause the
aforementioned corruption: We cannot allow any journal replay to
overwrite blocks associated with a glock once it is held.
The "live" glock which is now used to signal when a withdraw
occurs. When a withdraw occurs, the node signals its withdraw by
dequeueing the "live" glock and trying to enqueue it in EX mode,
thus forcing the other nodes to all see a demote request, by way
of a "1CB" (one callback) try lock. The "live" glock is not
granted in EX; the callback is only just used to indicate a
withdraw has occurred.
Note that all nodes in the cluster must wait for the recovering
node to finish replaying the withdrawing node's journal before
continuing. To this end, it checks that the journals are clean
multiple times in a retry loop.
Also note that the withdraw function may be called from a wide
variety of situations, and therefore, we need to take extra
precautions to make sure pointers are valid before using them in
many circumstances.
We also need to take care when glocks decide to withdraw, since
the withdraw code now uses glocks.
Also, before this patch, if a process encountered an error and
decided to withdraw, if another process was already withdrawing,
the second withdraw would be silently ignored, which set it free
to unlock its glocks. That's correct behavior if the original
withdrawer encounters further errors down the road. But if
secondary waiters don't wait for the journal replay, unlocking
glocks will allow other nodes to use them, despite the fact that
the journal containing those blocks is being replayed. The
replay needs to finish before our glocks are released to other
nodes. IOW, secondary withdraws need to wait for the first
withdraw to finish.
For example, if an rgrp glock is unlocked by a process that didn't
wait for the first withdraw, a journal replay could introduce file
system corruption by replaying a rgrp block that has already been
granted to a different cluster node.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
We need to allow some glocks to be enqueued, dequeued, promoted, and demoted
when we're withdrawn. For example, to maintain metadata integrity, we should
disallow the use of inode and rgrp glocks when withdrawn. Other glocks, like
iopen or the transaction glocks may be safely used because none of their
metadata goes through the journal. So in general, we should disallow all
glocks with an address space, and allow all the others. One exception is:
we need to allow our active journal to be demoted so others may recover it.
Allowing glocks after withdraw gives us the ability to take appropriate
action (in a following patch) to have our journal properly replayed by
another node rather than just abandoning the current transactions and
pretending nothing bad happened, leaving the other nodes free to modify
the blocks we had in our journal, which may result in file system
corruption.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Before this patch, the rgrp code had a serious problem related to
how it managed buffer_heads for resource groups. The problem caused
file system corruption, especially in cases of journal replay.
When an rgrp glock was demoted to transfer ownership to a
different cluster node, do_xmote() first calls rgrp_go_sync and then
rgrp_go_inval, as expected. When it calls rgrp_go_sync, that called
gfs2_rgrp_brelse() that dropped the buffer_head reference count.
In most cases, the reference count went to zero, which is right.
However, there were other places where the buffers are handled
differently.
After rgrp_go_sync, do_xmote called rgrp_go_inval which called
gfs2_rgrp_brelse a second time, then rgrp_go_inval's call to
truncate_inode_pages_range would get rid of the pages in memory,
but only if the reference count drops to 0.
Unfortunately, gfs2_rgrp_brelse was setting bi->bi_bh = NULL.
So when rgrp_go_sync called gfs2_rgrp_brelse, it lost the pointer
to the buffer_heads in cases where the reference count was still 1.
Therefore, when rgrp_go_inval called gfs2_rgrp_brelse a second time,
it failed the check for "if (bi->bi_bh)" and thus failed to call
brelse a second time. Because of that, the reference count on those
buffers sometimes failed to drop from 1 to 0. And that caused
function truncate_inode_pages_range to keep the pages in page cache
rather than freeing them.
The next time the rgrp glock was acquired, the metadata read of
the rgrp buffers re-used the pages in memory, which were now
wrong because they were likely modified by the other node who
acquired the glock in EX (which is why we demoted the glock).
This re-use of the page cache caused corruption because changes
made by the other nodes were never seen, so the bitmaps were
inaccurate.
For some reason, the problem became most apparent when journal
replay forced the replay of rgrps in memory, which caused newer
rgrp data to be overwritten by the older in-core pages.
A big part of the problem was that the rgrp buffer were released
in multiple places: The go_unlock function would release them when
the glock was released rather than when the glock is demoted,
which is clearly wrong because our intent was to cache them until
the glock is demoted from SH or EX.
This patch attempts to clean up the mess and make one consistent
and centralized mechanism for managing the rgrp buffer_heads by
implementing several changes:
1. It eliminates the call to gfs2_rgrp_brelse() from rgrp_go_sync.
We don't want to release the buffers or zero the pointers when
syncing for the reasons stated above. It only makes sense to
release them when the glock is actually invalidated (go_inval).
And when we do, then we set the bh pointers to NULL.
2. The go_unlock function (which was only used for rgrps) is
eliminated, as we've talked about doing many times before.
The go_unlock function was called too early in the glock dq
process, and should not happen until the glock is invalidated.
3. It also eliminates the call to rgrp_brelse in gfs2_clear_rgrpd.
That will now happen automatically when the rgrp glocks are
demoted, and shouldn't happen any sooner or later than that.
Instead, function gfs2_clear_rgrpd has been modified to demote
the rgrp glocks, and therefore, free those pages, before the
remaining glocks are culled by gfs2_gl_hash_clear. This
prevents the gl_object from hanging around when the glocks are
culled.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>
The dlm lockspace is set up to have lock value blocks of GDLM_LVB_SIZE bytes,
and dlm is the only lock manager we support, so there is no point in claiming
that the lock value block could have any other size.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
This patch closes a timing window in which two processes compete
and overlap in the execution of do_xmote for the same glock:
Process A Process B
------------------------------------ -----------------------------
1. Grabs gl_lockref and calls do_xmote
2. Grabs gl_lockref but is blocked
3. Sets GLF_INVALIDATE_IN_PROGRESS
4. Unlocks gl_lockref
5. Calls do_xmote
6. Call glops->go_sync
7. test_and_clear_bit GLF_DIRTY
8. Call gfs2_log_flush Call glops->go_sync
9. (slow IO, so it blocks a long time) test_and_clear_bit GLF_DIRTY
It's not dirty (step 7) returns
10. Tests GLF_INVALIDATE_IN_PROGRESS
11. Calls go_inval (rgrp_go_inval)
12. gfs2_rgrp_relse does brelse
13. truncate_inode_pages_range
14. Calls lm_lock UN
In step 14 we've just told dlm to give the glock to another node
when, in fact, process A has not finished the IO and synced all
buffer_heads to disk and make sure their revokes are done.
This patch fixes the problem by changing the GLF_INVALIDATE_IN_PROGRESS
to use test_and_set_bit, and if the bit is already set, process B just
ignores it and trusts that process A will do the do_xmote in the proper
order.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Add function gfs2_withdrawn and replace all checks for the SDF_WITHDRAWN
bit to call it. This does not change the logic or function of gfs2, and
it facilitates later improvements to the withdraw sequence.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Because s_vfs_rename_mutex is not cluster-wide, multiple nodes can
reverse the roles of which directories are "old" and which are "new" for
the purposes of rename. This can cause deadlocks where two nodes end up
waiting for each other.
There can be several layers of directory dependencies across many nodes.
This patch fixes the problem by acquiring all gfs2_rename's inode glocks
asychronously and waiting for all glocks to be acquired. That way all
inodes are locked regardless of the order.
The timeout value for multiple asynchronous glocks is calculated to be
the total of the individual wait times for each glock times two.
Since gfs2_exchange is very similar to gfs2_rename, both functions are
patched in the same way.
A new async glock wait queue, sd_async_glock_wait, keeps a list of
waiters for these events. If gfs2's holder_wake function detects an
async holder, it wakes up any waiters for the event. The waiter only
tests whether any of its requests are still pending.
Since the glocks are sent to dlm asychronously, the wait function needs
to check to see which glocks, if any, were granted.
If a glock is granted by dlm (and therefore held), its minimum hold time
is checked and adjusted as necessary, as other glock grants do.
If the event times out, all glocks held thus far must be dequeued to
resolve any existing deadlocks. Then, if there are any outstanding
locking requests, we need to loop around and wait for dlm to respond to
those requests too. After we release all requests, we return -ESTALE to
the caller (vfs rename) which loops around and retries the request.
Node1 Node2
--------- ---------
1. Enqueue A Enqueue B
2. Enqueue B Enqueue A
3. A granted
6. B granted
7. Wait for B
8. Wait for A
9. A times out (since Node 1 holds A)
10. Dequeue B (since it was granted)
11. Wait for all requests from DLM
12. B Granted (since Node2 released it in step 10)
13. Rename
14. Dequeue A
15. DLM Grants A
16. Dequeue A (due to the timeout and since we
no longer have B held for our task).
17. Dequeue B
18. Return -ESTALE to vfs
19. VFS retries the operation, goto step 1.
This release-all-locks / acquire-all-locks may slow rename / exchange
down as both nodes struggle in the same way and do the same thing.
However, this will only happen when there is contention for the same
inodes, which ought to be rare.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
This patch moves the code that updates glock minimum hold
time to a separate function. This will be called by a future
patch.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
This patch fixes three places in which temporary character buffers
could overflow due to the addition of the file system id from patch
3792ce973f. Thanks to Dan Carpenter for pointing it out.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Before this patch, if a glock error was encountered, the glock with
the problem was dumped. But sometimes you may have lots of file systems
mounted, and that doesn't tell you which file system it was for.
This patch adds a new boolean parameter fsid to the dump_glock family
of functions. For non-error cases, such as dumping the glocks debugfs
file, the fsid is not dumped in order to keep lock dumps and glocktop
as clean as possible. For all error cases, such as GLOCK_BUG_ON, the
file system id is now printed. This will make it easier to debug.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Before this patch, the superblock flag indicating when a file system
is withdrawn was called SDF_SHUTDOWN. This patch simply renames it to
the more obvious SDF_WITHDRAWN.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Use IS_ERR_OR_NULL where appropriate.
(Several more places converted by Andreas.)
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Another round of SPDX header file fixes for 5.2-rc4
These are all more "GPL-2.0-or-later" or "GPL-2.0-only" tags being
added, based on the text in the files. We are slowly chipping away at
the 700+ different ways people tried to write the license text. All of
these were reviewed on the spdx mailing list by a number of different
people.
We now have over 60% of the kernel files covered with SPDX tags:
$ ./scripts/spdxcheck.py -v 2>&1 | grep Files
Files checked: 64533
Files with SPDX: 40392
Files with errors: 0
I think the majority of the "easy" fixups are now done, it's now the
start of the longer-tail of crazy variants to wade through.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'spdx-5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull yet more SPDX updates from Greg KH:
"Another round of SPDX header file fixes for 5.2-rc4
These are all more "GPL-2.0-or-later" or "GPL-2.0-only" tags being
added, based on the text in the files. We are slowly chipping away at
the 700+ different ways people tried to write the license text. All of
these were reviewed on the spdx mailing list by a number of different
people.
We now have over 60% of the kernel files covered with SPDX tags:
$ ./scripts/spdxcheck.py -v 2>&1 | grep Files
Files checked: 64533
Files with SPDX: 40392
Files with errors: 0
I think the majority of the "easy" fixups are now done, it's now the
start of the longer-tail of crazy variants to wade through"
* tag 'spdx-5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (159 commits)
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 450
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 449
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 448
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 446
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 445
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 444
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 443
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 442
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 440
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 438
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 437
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 436
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 435
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 434
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 433
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 432
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 431
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 430
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 429
...
Commit 73118ca8ba introduced a glock reference counting bug in
gfs2_trans_remove_revoke. Given that, replacing gl_revokes with a GLF flag is
no longer useful, so revert that commit.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Based on 1 normalized pattern(s):
this copyrighted material is made available to anyone wishing to use
modify copy or redistribute it subject to the terms and conditions
of the gnu general public license version 2
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 44 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531081038.653000175@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The gl_revokes value determines how many outstanding revokes a glock has
on the superblock revokes list; this is used to avoid unnecessary log
flushes. However, gl_revokes is only ever tested for being zero, and it's
only decremented in revoke_lo_after_commit, which removes all revokes
from the list, so we know that the gl_revoke values of all the glocks on
the list will reach zero. Therefore, we can replace gl_revokes with a
bit flag. This saves an atomic counter in struct gfs2_glock.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
This patch has to do with the life cycle of glocks and buffers. When
gfs2 metadata or journaled data is queued to be written, a gfs2_bufdata
object is assigned to track the buffer, and that is queued to various
lists, including the glock's gl_ail_list to indicate it's on the active
items list. Once the page associated with the buffer has been written,
it is removed from the ail list, but its life isn't over until a revoke
has been successfully written.
So after the block is written, its bufdata object is moved from the
glock's gl_ail_list to a file-system-wide list of pending revokes,
sd_log_le_revoke. At that point the glock still needs to track how many
revokes it contributed to that list (in gl_revokes) so that things like
glock go_sync can ensure all the metadata has been not only written, but
also revoked before the glock is granted to a different node. This is
to guarantee journal replay doesn't replay the block once the glock has
been granted to another node.
Ross Lagerwall recently discovered a race in which an inode could be
evicted, and its glock freed after its ail list had been synced, but
while it still had unwritten revokes on the sd_log_le_revoke list. The
evict decremented the glock reference count to zero, which allowed the
glock to be freed. After the revoke was written, function
revoke_lo_after_commit tried to adjust the glock's gl_revokes counter
and clear its GLF_LFLUSH flag, at which time it referenced the freed
glock.
This patch fixes the problem by incrementing the glock reference count
in gfs2_add_revoke when the glock's first bufdata object is moved from
the glock to the global revokes list. Later, when the glock's last such
bufdata object is freed, the reference count is decremented. This
guarantees that whichever process finishes last (the revoke writing or
the evict) will properly free the glock, and neither will reference the
glock after it has been freed.
Reported-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Under certain conditions, lru_count may drop below zero resulting in
a large amount of log spam like this:
vmscan: shrink_slab: gfs2_dump_glock+0x3b0/0x630 [gfs2] \
negative objects to delete nr=-1
This happens as follows:
1) A glock is moved from lru_list to the dispose list and lru_count is
decremented.
2) The dispose function calls cond_resched() and drops the lru lock.
3) Another thread takes the lru lock and tries to add the same glock to
lru_list, checking if the glock is on an lru list.
4) It is on a list (actually the dispose list) and so it avoids
incrementing lru_count.
5) The glock is moved to lru_list.
5) The original thread doesn't dispose it because it has been re-added
to the lru list but the lru_count has still decreased by one.
Fix by checking if the LRU flag is set on the glock rather than checking
if the glock is on some list and rearrange the code so that the LRU flag
is added/removed precisely when the glock is added/removed from lru_list.
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Mark Syms has reported seeing tasks that are stuck waiting in
find_insert_glock. It turns out that struct lm_lockname contains four padding
bytes on 64-bit architectures that function glock_waitqueue doesn't skip when
hashing the glock name. As a result, we can end up waking up the wrong
waitqueue, and the waiting tasks may be stuck forever.
Fix that by using ht_parms.key_len instead of sizeof(struct lm_lockname) for
the key length.
Reported-by: Mark Syms <mark.syms@citrix.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
When calling debugfs functions, there is no need to ever check the
return value. The function can work or not, but the code logic should
never do something different based on this.
There is no need to save the dentries for the debugfs files, so drop
those variables to save a bit of space and make the code simpler.
Cc: Bob Peterson <rpeterso@redhat.com>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: cluster-devel@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
This patch is based on an idea from Steve Whitehouse. The idea is
to dump the number of pages for inodes in the glock dumps.
The additional locking required me to drop const from quite a few
places.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Before this patch, various errors and messages were reported using
the pr_* functions: pr_err, pr_warn, pr_info, etc., but that does
not tell you which gfs2 mount had the problem, which is often vital
to debugging. This patch changes the calls from pr_* to fs_* in
most of the messages so that the file system id is printed along
with the message.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Function rhashtable_walk_peek is problematic because there is no
guarantee that the glock previously returned still exists; when that key
is deleted, rhashtable_walk_peek can end up returning a different key,
which will cause an inconsistent glock dump. Fix this by keeping track
of the current glock in the seq file iterator functions instead.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Restore an optimization removed in commit 7f19449553 "Fix debugfs glocks
dump": keep the glock hash table iterator active while the glock dump
file is held open. This avoids having to rescan the hash table from the
start for each read, with quadratically rising runtime.
In addition, use rhastable_walk_peek for resuming a glock dump at the
current position: when a glock doesn't fit in the provided buffer
anymore, the next read must revisit the same glock.
Finally, also restart the dump from the first entry when we notice that
the hash table has been resized in gfs2_glock_seq_start.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Most callers of rhashtable_walk_start don't care about a resize event
which is indicated by a return value of -EAGAIN. So calls to
rhashtable_walk_start are wrapped wih code to ignore -EAGAIN. Something
like this is common:
ret = rhashtable_walk_start(rhiter);
if (ret && ret != -EAGAIN)
goto out;
Since zero and -EAGAIN are the only possible return values from the
function this check is pointless. The condition never evaluates to true.
This patch changes rhashtable_walk_start to return void. This simplifies
code for the callers that ignore -EAGAIN. For the few cases where the
caller cares about the resize event, particularly where the table can be
walked in mulitple parts for netlink or seq file dump, the function
rhashtable_walk_start_check has been added that returns -EAGAIN on a
resize event.
Signed-off-by: Tom Herbert <tom@quantonium.net>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
The switch to rhashtables (commit 88ffbf3e03) broke the debugfs glock
dump (/sys/kernel/debug/gfs2/<device>/glocks) for dumps bigger than a
single buffer: the right function for restarting an rhashtable iteration
from the beginning of the hash table is rhashtable_walk_enter;
rhashtable_walk_stop + rhashtable_walk_start will just resume from the
current position.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Cc: stable@vger.kernel.org # v4.3+
rhashtable_params are not supposed to change at runtime. All
Functions rhashtable_* working with const rhashtable_params
provided by <linux/rhashtable.h>. So mark the non-const structs
as const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
This patch cleans up various pieces of GFS2 to avoid sparse errors.
This doesn't fix them all, but it fixes several. The first error,
in function glock_hash_walk was a genuine bug where the rhashtable
could be started and not stopped.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
The prepare_to_wait_on_glock and finish_wait_on_glock functions introduced in
commit 56a365be "gfs2: gfs2_glock_get: Wait on freeing glocks" are
better removed, resulting in cleaner code.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
gfs2_evict_inode is called to free inodes under memory pressure. The
function calls into DLM when an inode's last cluster-wide reference goes
away (remote unlink) and to release the glock and associated DLM lock
before finally destroying the inode. However, if DLM is blocked on
memory to become available, calling into DLM again will deadlock.
Avoid that by decoupling releasing glocks from destroying inodes in that
case: with gfs2_glock_queue_put, glocks will be dequeued asynchronously
in work queue context, when the associated inodes have likely already
been destroyed.
With this change, inodes can end up being unlinked, remote-unlink can be
triggered, and then the inode can be reallocated before all
remote-unlink callbacks are processed. To detect that, revalidate the
link count in gfs2_evict_inode to make sure we're not deleting an
allocated, referenced inode.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Keep glocks in their hash table until they are freed instead of removing
them when their last reference is dropped. This allows to wait for any
previous instances of a glock to go away in gfs2_glock_get before
creating a new glocks.
Special thanks to Andy Price for finding and fixing a problem which also
required us to delete the rcu_read_unlock from the error case in function
gfs2_glock_get.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Before this patch, glock_dq would call gfs2_glock_remove_from_lru.
For glocks that are never put on the LRU, such as the transaction
glock, this just takes the spin_lock, determines there's nothing to
be done because the list is empty, then unlocks again. This was
causing unnecessary lock contention on the lru_lock spin_lock.
This patch adds a check for GLOF_LRU in the glops before taking
the spin_lock.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Before commit 88ffbf3e03 "GFS2: Use resizable hash table for glocks",
glocks were freed via call_rcu to allow reading the glock hashtable
locklessly using rcu. This was then changed to free glocks immediately,
which made reading the glock hashtable unsafe. Bring back the original
code for freeing glocks via call_rcu.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Cc: stable@vger.kernel.org # 4.3+
This patch adds a standardized queueing mechanism for glock work
with spin_lock protection to prevent races.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
This bug fixes a regression introduced by patch 0d1c7ae9d8.
The intent of the patch was to stop promoting glocks after a
file system is withdrawn due to a variety of errors, because doing
so results in a BUG(). (You should be able to unmount after a
withdraw rather than having the kernel panic.)
Unfortunately, it also stopped demotions, so glocks could not be
unlocked after withdraw, which means the unmount would hang.
This patch allows function do_xmote to demote locks to an
unlocked state after a withdraw, but not promote them.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Switch from rhashtable_lookup_insert_fast + rhashtable_lookup_fast to
rhashtable_lookup_get_insert_fast, which is cleaner and avoids an extra
rhashtable lookup.
At the same time, turn the retry loop in gfs2_glock_get into an infinite
loop. The lookup or insert will eventually succeed, usually very fast,
but there is no reason to give up trying at a fixed number of
iterations.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
As per a suggestion by Linus, don't pack struct lm_lockname: we did that
because the struct is used as a rhashtable key, but packing tells the
compiler that the 64-bit fields in the struct may be unaligned, causing
it to generate worse code on some architectures. Instead, rearrange the
fields in the struct so that there is no padding between fields, and
exclude any tail padding from the hash key size.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Both functions are identical except for the seq_operations used.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Function rhashtable_walk_init is deprecated.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
When the GFS2 file system withdraws due to metadata corruption, it
often has outstanding transactions in the journal and delayed work
queued for its glocks. This patch adds some new checks for a
withdrawn file system before proceeding with operations that would
obviously cause a BUG() to be triggered. That allows GFS2 to be
safely unmounted rather than cause the system to go down.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Andy Price wrote this patch to close a nasty race condition
that allows access to glocks that are being destroyed. Without
this patch, GFS2 is vulnerable to random corruption and kernel
panic.
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Merge tag 'gfs2-4.11.addendum' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2
Pull GFS2 fix from Bob Peterson:
"This is an addendum for the 4.11 merge window.
Andy Price wrote this patch to close a nasty race condition that
allows access to glocks that are being destroyed. Without this patch,
GFS2 is vulnerable to random corruption and kernel panic"
* tag 'gfs2-4.11.addendum' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
gfs2: Add missing rcu locking for glock lookup
We must hold the rcu read lock across looking up glocks and trying to
bump their refcount to prevent the glocks from being freed in between.
Cc: <stable@vger.kernel.org> # 4.3+
Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Pull networking updates from David Miller:
"Highlights:
1) Support TX_RING in AF_PACKET TPACKET_V3 mode, from Sowmini
Varadhan.
2) Simplify classifier state on sk_buff in order to shrink it a bit.
From Willem de Bruijn.
3) Introduce SIPHASH and it's usage for secure sequence numbers and
syncookies. From Jason A. Donenfeld.
4) Reduce CPU usage for ICMP replies we are going to limit or
suppress, from Jesper Dangaard Brouer.
5) Introduce Shared Memory Communications socket layer, from Ursula
Braun.
6) Add RACK loss detection and allow it to actually trigger fast
recovery instead of just assisting after other algorithms have
triggered it. From Yuchung Cheng.
7) Add xmit_more and BQL support to mvneta driver, from Simon Guinot.
8) skb_cow_data avoidance in esp4 and esp6, from Steffen Klassert.
9) Export MPLS packet stats via netlink, from Robert Shearman.
10) Significantly improve inet port bind conflict handling, especially
when an application is restarted and changes it's setting of
reuseport. From Josef Bacik.
11) Implement TX batching in vhost_net, from Jason Wang.
12) Extend the dummy device so that VF (virtual function) features,
such as configuration, can be more easily tested. From Phil
Sutter.
13) Avoid two atomic ops per page on x86 in bnx2x driver, from Eric
Dumazet.
14) Add new bpf MAP, implementing a longest prefix match trie. From
Daniel Mack.
15) Packet sample offloading support in mlxsw driver, from Yotam Gigi.
16) Add new aquantia driver, from David VomLehn.
17) Add bpf tracepoints, from Daniel Borkmann.
18) Add support for port mirroring to b53 and bcm_sf2 drivers, from
Florian Fainelli.
19) Remove custom busy polling in many drivers, it is done in the core
networking since 4.5 times. From Eric Dumazet.
20) Support XDP adjust_head in virtio_net, from John Fastabend.
21) Fix several major holes in neighbour entry confirmation, from
Julian Anastasov.
22) Add XDP support to bnxt_en driver, from Michael Chan.
23) VXLAN offloads for enic driver, from Govindarajulu Varadarajan.
24) Add IPVTAP driver (IP-VLAN based tap driver) from Sainath Grandhi.
25) Support GRO in IPSEC protocols, from Steffen Klassert"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1764 commits)
Revert "ath10k: Search SMBIOS for OEM board file extension"
net: socket: fix recvmmsg not returning error from sock_error
bnxt_en: use eth_hw_addr_random()
bpf: fix unlocking of jited image when module ronx not set
arch: add ARCH_HAS_SET_MEMORY config
net: napi_watchdog() can use napi_schedule_irqoff()
tcp: Revert "tcp: tcp_probe: use spin_lock_bh()"
net/hsr: use eth_hw_addr_random()
net: mvpp2: enable building on 64-bit platforms
net: mvpp2: switch to build_skb() in the RX path
net: mvpp2: simplify MVPP2_PRS_RI_* definitions
net: mvpp2: fix indentation of MVPP2_EXT_GLOBAL_CTRL_DEFAULT
net: mvpp2: remove unused register definitions
net: mvpp2: simplify mvpp2_bm_bufs_add()
net: mvpp2: drop useless fields in mvpp2_bm_pool and related code
net: mvpp2: remove unused 'tx_skb' field of 'struct mvpp2_tx_queue'
net: mvpp2: release reference to txq_cpu[] entry after unmapping
net: mvpp2: handle too large value in mvpp2_rx_time_coal_set()
net: mvpp2: handle too large value handling in mvpp2_rx_pkts_coal_set()
net: mvpp2: remove useless arguments in mvpp2_rx_{pkts, time}_coal_set
...
1. Andy Price submitted a patch to make gfs2_write_full_page a
static function.
2. Dan Carpenter submitted a patch to fix a ERR_PTR thinko.
I've also got a few patches, three of which fix bugs related to
deleting very large files, which cause GFS2 to run out of
journal space:
3. The first one prevents GFS2 delete operation from requesting too
much journal space.
4. The second one fixes a problem whereby GFS2 can hang because it
wasn't taking journal space demand into its calculations.
5. The third one wakes up IO waiters when a flush is done to restart
processes stuck waiting for journal space to become available.
The other three patches are a performance improvement related to
spin_lock contention between multiple writers:
6. The "tr_touched" variable was switched to a flag to be more atomic
and eliminate the possibility of some races.
7. Function meta_lo_add was moved inline with its only caller to make
the code more readable and efficient.
8. Contention on the gfs2_log_lock spinlock was greatly reduced by
avoiding the lock altogether in cases where we don't really need
it: buffers that already appear in the appropriate metadata list
for the journal. Many thanks to Steve Whitehouse for the ideas and
principles behind these patches.
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Merge tag 'gfs2-4.11.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2
Pull GFS2 updates from Robert Peterson:
"We've got eight GFS2 patches for this merge window:
- Andy Price submitted a patch to make gfs2_write_full_page a static
function.
- Dan Carpenter submitted a patch to fix a ERR_PTR thinko.
Three patches fix bugs related to deleting very large files, which
cause GFS2 to run out of journal space:
- The first one prevents GFS2 delete operation from requesting too
much journal space.
- The second one fixes a problem whereby GFS2 can hang because it
wasn't taking journal space demand into its calculations.
- The third one wakes up IO waiters when a flush is done to restart
processes stuck waiting for journal space to become available.
The final three patches are a performance improvement related to
spin_lock contention between multiple writers:
- The "tr_touched" variable was switched to a flag to be more atomic
and eliminate the possibility of some races.
- Function meta_lo_add was moved inline with its only caller to make
the code more readable and efficient.
- Contention on the gfs2_log_lock spinlock was greatly reduced by
avoiding the lock altogether in cases where we don't really need
it: buffers that already appear in the appropriate metadata list
for the journal. Many thanks to Steve Whitehouse for the ideas and
principles behind these patches"
* tag 'gfs2-4.11.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
gfs2: Make gfs2_write_full_page static
GFS2: Reduce contention on gfs2_log_lock
GFS2: Inline function meta_lo_add
GFS2: Switch tr_touched to flag in transaction
GFS2: Wake up io waiters whenever a flush is done
GFS2: Made logd daemon take into account log demand
GFS2: Limit number of transaction blocks requested for truncates
GFS2: Fix reference to ERR_PTR in gfs2_glock_iter_next
The function glock_hash_walk walks the rhashtable by hand. This
is broken because if it catches the hash table in the middle of
a rehash, then it will miss entries.
This patch replaces the manual walk by using the rhashtable walk
interface.
Fixes: 88ffbf3e03 ("GFS2: Use resizable hash table for glocks")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
ktime_set(S,N) was required for the timespec storage type and is still
useful for situations where a Seconds and Nanoseconds part of a time value
needs to be converted. For anything where the Seconds argument is 0, this
is pointless and can be replaced with a simple assignment.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
This was entirely automated, using the script by Al:
PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
$(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)
to do the replacement at the end of the merge window.
Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch fixes a place where function gfs2_glock_iter_next can
reference an invalid error pointer.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
register_shrinker can fail after commit 1d3d4437ea ("vmscan: per-node
deferred work"), we should detect the failure of it, otherwise we may
fail to register shrinker after gfs2 module was been inited successfully.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Replace 1 << value shift by more explicit BIT() macro
Also fixes two bare unsigned definitions:
WARNING: Prefer 'unsigned int' to bare use of 'unsigned'
+ unsigned hsize = BIT(ip->i_depth);
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Make the code more readable by cleaning up the different ways of
initializing lock holders and checking for initialized lock holders:
mark lock holders as uninitialized by setting the holder's glock to NULL
(gfs2_holder_mark_uninitialized) instead of zeroing out the entire
object or using a separate flag. Recognize initialized holders by their
non-NULL glock (gfs2_holder_initialized). Don't zero out holder objects
which are immeditiately initialized via gfs2_holder_init or
gfs2_glock_nq_init.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Now that gfs2_lookup_by_inum only takes the inode glock for new inodes
(and not for cached inodes anymore), there no longer is a need to
optimize the cached-inode case in gfs2_get_dentry or delete_work_func,
and gfs2_ilookup can be removed.
In addition, gfs2_get_dentry wasn't checking the GFS2_DIF_SYSTEM flag in
i_diskflags in the gfs2_ilookup case (see gfs2_lookup_by_inum); this
inconsistency goes away as well.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
The current gfs2_lookup_by_inum takes the glock of a presumed inode
identified by block number, verifies that the block is indeed an inode,
and then instantiates and reads the new inode via gfs2_inode_lookup.
However, instantiating a new inode may block on freeing a previous
instance of that inode (__wait_on_freeing_inode), and freeing an inode
requires to take the glock already held, leading to lock inversion and
deadlock.
Fix this by first instantiating the new inode, then verifying that the
block is an inode (if required), and then reading in the new inode, all
in gfs2_inode_lookup.
If the block we are looking for is not an inode, we discard the new
inode via iget_failed, which marks inodes as bad and unhashes them.
Other tasks waiting on that inode will get back a bad inode back from
ilookup or iget_locked; in that case, retry the lookup.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
- Abhi Das has two patches that fix a GFS2 splice issue (and an adjustment).
- Ben Marzinski has a patch which allows the proper unmount of a GFS2
file system after hitting a withdraw error.
- I have a patch to fix a problem where GFS2 would dereference an error
value, plus three cosmetic / refactoring patches.
- Daniel DeFreez has a patch to fix two glock reference count problems,
where GFS2 was not properly "uninitializing" its glock holder on error
paths.
- Denys Vlasenko has a patch to change a function to not be inlined,
thus reducing the memory footprint of the GFS2 module.
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Merge tag 'gfs2-4.7.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2
Pull GFS2 updates from Bob Peterson:
"We've got nine patches this time:
- Abhi Das has two patches that fix a GFS2 splice issue (and an
adjustment).
- Ben Marzinski has a patch which allows the proper unmount of a GFS2
file system after hitting a withdraw error.
- I have a patch to fix a problem where GFS2 would dereference an
error value, plus three cosmetic / refactoring patches.
- Daniel DeFreez has a patch to fix two glock reference count
problems, where GFS2 was not properly "uninitializing" its glock
holder on error paths.
- Denys Vlasenko has a patch to change a function to not be inlined,
thus reducing the memory footprint of the GFS2 module"
* tag 'gfs2-4.7.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
GFS2: Refactor gfs2_remove_from_journal
GFS2: Remove allocation parms from gfs2_rbm_find
gfs2: use inode_lock/unlock instead of accessing i_mutex directly
GFS2: Add calls to gfs2_holder_uninit in two error handlers
GFS2: Don't dereference inode in gfs2_inode_lookup until it's valid
GFS2: fs/gfs2/glock.c: Deinline do_error, save 1856 bytes
gfs2: Use gfs2 wrapper to sync inode before calling generic_file_splice_read()
GFS2: Get rid of dead code in inode_go_demote_ok
GFS2: ignore unlock failures after withdraw
This function compiles to 522 bytes of machine code.
Error paths are not very time critical.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
In certain cases, the 802.11 mesh pathtable code wants to
iterate over all of the entries in the forwarding table from
the receive path, which is inside an RCU read-side critical
section. Enable walks inside atomic sections by allowing
GFP_ATOMIC allocations for the walker state.
Change all existing callsites to pass in GFP_KERNEL.
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Bob Copeland <me@bobcopeland.com>
[also adjust gfs2/glock.c and rhashtable tests]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
After gfs2 has withdrawn the filesystem, it may still have many locks not
in the unlocked state. If it is using lock_dlm, it will failed trying
the unlocks since it has already unmounted the lock manager. Instead, it
should set the SDF_SKIP_DLM_UNLOCK flag on withdraw, to signal that
it can skip the lock_manager on unlocks, and failback to lock_nolock
style unlocking.
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
This patch basically reverts a very old patch from 2008,
7a9f53b3c1, with the title
"Alternate gfs2_iget to avoid looking up inodes being freed".
The original patch was designed to avoid a deadlock caused by lock
ordering with try_rgrp_unlink. The patch forced the function to not
find inodes that were being removed by VFS. The problem is, that
made it impossible for nodes to delete their own unlinked dinodes
after a certain point in time, because the inode needed was not found
by this filtering process. There is no longer a need for the patch,
since function try_rgrp_unlink no longer locks the inode: All it does
is queue the glock onto the delete work_queue, so there should be no
more deadlock.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This patch tries to prevent delete work (queued via iopen callback)
from executing if the glock is currently being used to create
a new inode.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
This patch fixes an error condition in which an inode is partially
created in gfs2_create_inode() but then some error is discovered,
which causes it to fail and call iput() before the iopen glock is
created or held. In that case, gfs2_delete_inode would try to
unlock an iopen glock that doesn't yet exist. Therefore, we test
its holder (which must exist) for the HIF_HOLDER bit before trying
to dq it.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
At some point in the past, we used to have a timeout when GFS2 was
unmounting, trying to clear out its glocks. If the timeout expires,
it would dump the remaining glocks to the kernel messages so that
developers can debug the problem. That timeout was eliminated,
probably by accident. This patch reintroduces it.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
This patch makes no functional changes. Its goal is to reduce the
size of the gfs2 inode in memory by rearranging structures and
changing the size of some variables within the structure.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
This lockdep splat was being triggered on umount:
[55715.973122] ===============================
[55715.980169] [ INFO: suspicious RCU usage. ]
[55715.981021] 4.3.0-11553-g8d3de01-dirty #15 Tainted: G W
[55715.982353] -------------------------------
[55715.983301] fs/gfs2/glock.c:1427 suspicious rcu_dereference_protected() usage!
The code it refers to is the rht_for_each_entry_safe usage in
glock_hash_walk. The condition that triggers the warning is
lockdep_rht_bucket_is_held(tbl, hash) which is checked in the
__rcu_dereference_protected macro.
The rhashtable buckets are not changed in glock_hash_walk so it's safe
to rely on the rcu protection. Replace the rht_for_each_entry_safe()
usage with rht_for_each_entry_rcu(), which doesn't care whether the
bucket lock is held if the rcu read lock is held.
Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Commit e66cf161 replaced the gl_spin spinlock in struct gfs2_glock with a
gl_lockref lockref and defined gl_spin as gl_lockref.lock (the spinlock in
gl_lockref). Remove that define to make the references to gl_lockref.lock more
obvious.
Signed-off-by: Andreas Gruenbacher <andreas.gruenbacher@gmail.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
It seems cleaner to avoid the temporary value here.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
None of these statistics can meaningfully be negative, and the
numerator for do_div() must have the type u64. The generic
implementation of do_div() used on some 32-bit architectures asserts
that, resulting in a compiler error in gfs2_rgrp_congested().
Fixes: 0166b197c2 ("GFS2: Average in only non-zero round-trip times ...")
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Acked-by: Andreas Gruenbacher <agruenba@redhat.com>
This patch changes the glock hash table from a normal hash table to
a resizable hash table, which scales better. This also simplifies
a lot of code.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
What uniquely identifies a glock in the glock hash table is not
gl_name, but gl_name and its superblock pointer. This patch makes
the gl_name field correspond to a unique glock identifier. That will
allow us to simplify hashing with a future patch, since the hash
algorithm can then take the gl_name and hash its components in one
operation.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
