Add a TODO to remember fixing REQ_FUA | REQ_PREFLUSH for fast commit
buffers. Also, fix a typo in top level comment in fast_commit.c
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201106035911.1942128-15-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This patch removes the deduplicates the code that implements waiting
on inode that's being committed. That code is moved into a new
function.
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201106035911.1942128-14-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Fast commit buffers should be filled in before toucing their
state. Remove code that sets buffer state as dirty before the buffer
is passed to the file system.
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201106035911.1942128-12-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Fast commit performance can be optimized if commit thread doesn't wait
for ongoing fast commits to complete until the transaction enters
T_FLUSH state. Document this optimization.
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201106035911.1942128-11-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
In jbd2_fc_end_commit_fallback(), we know which tid to commit. There's
no need for caller to pass it.
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201106035911.1942128-10-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Variables journal->j_fc_off, journal->j_fc_wbuf are accessed during
commit path. Since today we allow only one process to perform a fast
commit, there is no need take state lock before accessing these
variables. This patch removes these locks and adds comments to
describe this.
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201106035911.1942128-9-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This patch removes jbd2_fc_init() API and its related functions to
simplify enabling fast commits. With this change, the number of fast
commit blocks to use is solely determined by the JBD2 layer. So, we
move the default value for minimum number of fast commit blocks from
ext4/fast_commit.h to include/linux/jbd2.h. However, whether or not to
use fast commits is determined by the file system. The file system
just sets the fast commit feature using
jbd2_journal_set_features(). JBD2 layer then determines how many
blocks to use for fast commits (based on the value found in the JBD2
superblock).
Note that the JBD2 feature flag of fast commits is just an indication
that there are fast commit blocks present on disk. It doesn't tell
JBD2 layer about the intent of the file system of whether to it wants
to use fast commit or not. That's why, we blindly clear the fast
commit flag in journal_reset() after the recovery is done.
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201106035911.1942128-7-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The on-disk superblock field sb->s_maxlen represents the total size of
the journal including the fast commit area and is no more the max
number of blocks available for a transaction. The maximum number of
blocks available to a transaction is reduced by the number of fast
commit blocks. So, this patch renames j_maxlen to j_total_len to
better represent its intent. Also, it adds a function to calculate max
number of bufs available for a transaction.
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201106035911.1942128-6-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Firstly, pass handle to all ext4_fc_track_* functions and use
transaction id found in handle->h_transaction->h_tid for tracking fast
commit updates. Secondly, don't pass inode to
ext4_fc_track_link/create/unlink functions. inode can be found inside
these functions as d_inode(dentry). However, rename path is an
exeception. That's because in that case, we need inode that's not same
as d_inode(dentry). To handle that, add a couple of low-level wrapper
functions that take inode and dentry as arguments.
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201106035911.1942128-5-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
ext4_fc_track_range() should only be called when blocks are added or
removed from an inode. So, the only places from where we need to call
this function are ext4_map_blocks(), punch hole, collapse / zero
range, truncate. Remove all the other redundant calls to ths function.
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201106035911.1942128-4-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
If inode gets evicted due to memory pressure, we have to remove it
from the fast commit list. However, that inode may have uncommitted
changes that fast commits will lose. So, just fall back to full
commits in this case. Also, rename the fast commit ineligiblity reason
from "EXT4_FC_REASON_MEM" to "EXT4_FC_REASON_MEM_NOMEM" for better
expression.
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201106035911.1942128-3-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Fast commit feature has flags in the file system as well in JBD2. The
meaning of fast commit feature flags can get confusing. Update docs
and code to add more documentation about it.
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20201106035911.1942128-2-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
It takes xattr_sem to check inline data again but without unlock it
in case not have. So unlock it before return.
Fixes: aef1c8513c ("ext4: let ext4_truncate handle inline data correctly")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://lore.kernel.org/r/1604370542-124630-1-git-send-email-joseph.qi@linux.alibaba.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Smatch complains that "i" can be uninitialized if we don't enter the
loop. I don't know if it's possible but we may as well silence this
warning.
[ Initialize i to sb->s_blocksize instead of 0. The only way the for
loop could be skipped entirely is the in-memory data structures, in
particular the bh->b_data for the on-disk superblock has gotten
corrupted enough that calculated value of group is >= to
ext4_get_groups_count(sb). In that case, we want to exit
immediately without allocating a block. -- TYT ]
Fixes: 8016e29f43 ("ext4: fast commit recovery path")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20201030114620.GB3251003@mwanda
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
The macro MOPT_Q is used to indicates the mount option is related to
quota stuff and is defined to be MOPT_NOSUPPORT when CONFIG_QUOTA is
disabled. Normally the quota options are handled explicitly, so it
didn't matter that the MOPT_STRING flag was missing, even though the
usrjquota and grpjquota mount options take a string argument. It's
important that's present in the !CONFIG_QUOTA case, since without
MOPT_STRING, the mount option matcher will match usrjquota= followed
by an integer, and will otherwise skip the table entry, and so "mount
option not supported" error message is never reported.
[ Fixed up the commit description to better explain why the fix
works. --TYT ]
Fixes: 26092bf524 ("ext4: use a table-driven handler for mount options")
Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
Link: https://lore.kernel.org/r/1603986396-28917-1-git-send-email-kaixuxia@tencent.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Alexei Starovoitov says:
====================
pull-request: bpf 2020-11-06
1) Pre-allocated per-cpu hashmap needs to zero-fill reused element, from David.
2) Tighten bpf_lsm function check, from KP.
3) Fix bpftool attaching to flow dissector, from Lorenz.
4) Use -fno-gcse for the whole kernel/bpf/core.c instead of function attribute, from Ard.
* git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
bpf: Update verification logic for LSM programs
bpf: Zero-fill re-used per-cpu map element
bpf: BPF_PRELOAD depends on BPF_SYSCALL
tools/bpftool: Fix attaching flow dissector
libbpf: Fix possible use after free in xsk_socket__delete
libbpf: Fix null dereference in xsk_socket__delete
libbpf, hashmap: Fix undefined behavior in hash_bits
bpf: Don't rely on GCC __attribute__((optimize)) to disable GCSE
tools, bpftool: Remove two unused variables.
tools, bpftool: Avoid array index warnings.
xsk: Fix possible memory leak at socket close
bpf: Add struct bpf_redir_neigh forward declaration to BPF helper defs
samples/bpf: Set rlimit for memlock to infinity in all samples
bpf: Fix -Wshadow warnings
selftest/bpf: Fix profiler test using CO-RE relocation for enums
====================
Link: https://lore.kernel.org/r/20201106221759.24143-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This reverts commit 16b5f5ce35
where it restructures do_reset. There are patches being tested that
would require major rework if this is committed first.
We will resend this after the other patches have been applied.
Signed-off-by: Dany Madden <drt@linux.ibm.com>
Link: https://lore.kernel.org/r/20201106191745.1679846-1-drt@linux.ibm.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit adds comments that label the MP tests' producer and consumer
processes, and also that label the "exists" clause as the bad outcome.
Reported-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
The use of "x" and "y" for message-passing tests is fine for people
familiar with memory models and litmus-test nomenclature, but is a bit
obtuse for others. This commit therefore substitutes "buf" for "x" and
"flag" for "y" for the MP tests. There are a few special-case MP tests
that use locks and these are unchanged. There is another MP test that
uses pointers, and this is changed to name the pointer "p".
Reported-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This commit adds type information for global variables in the litmus
tests in order to allow easier use with klitmus7.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Commit 39323c6 ("smp_mb__{before,after}_atomic(): update Documentation")
has a typo in CPU MEORY BARRIERS section:
"RMW functions that do not imply are memory barrier are ..." should be
"RMW functions that do not imply a memory barrier are ...".
This patch fixes this typo.
Signed-off-by: Fox Chen <foxhlchen@gmail.com>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
The Linux kernel has a number of categories of ordering primitives, which
are recorded in the LKMM implementation and hinted at by cheatsheet.txt.
But there is no overview of these categories, and such an overview
is needed in order to understand multithreaded LKMM litmus tests.
This commit therefore adds an ordering.txt as well as extracting a
control-dependencies.txt from memory-barriers.txt. It also updates the
README file.
[ paulmck: Apply Akira Yokosawa file-placement feedback. ]
[ paulmck: Apply Alan Stern feedback. ]
[ paulmck: Apply self-review feedback. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
The watchpoint encoding masks for size and address were off-by-one bit
each, with the size mask using 1 unnecessary bit and the address mask
missing 1 bit. However, due to the way the size is shifted into the
encoded watchpoint, we were effectively wasting and never using the
extra bit.
For example, on x86 with PAGE_SIZE==4K, we have 1 bit for the is-write
bit, 14 bits for the size bits, and then 49 bits left for the address.
Prior to this fix we would end up with this usage:
[ write<1> | size<14> | wasted<1> | address<48> ]
Fix it by subtracting 1 bit from the GENMASK() end and start ranges of
size and address respectively. The added static_assert()s verify that
the masks are as expected. With the fixed version, we get the expected
usage:
[ write<1> | size<14> | address<49> ]
Functionally no change is expected, since that extra address bit is
insignificant for enabled architectures.
Acked-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Currently, the units of ->init_fract are milliseconds while those of
->gp_sleep are jiffies. For consistency with each other and with the
argument of schedule_timeout_idle(), this commit changes the units of
->init_fract to jiffies.
This change does affect the backoff algorithm, but only on systems where
HZ is not 1000, and even there the change makes more sense, given that the
current setup would "back off" to the same number of jiffies repeatedly.
In contrast, with this change, the number of jiffies waited increases
on each pass through the loop in the rcu_tasks_wait_gp() function.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
For the rcutorture test summary log file console.log of virtual machines is
parsed. When a console.log contains "DEBUG", BUG counter is incremented
because regular expression does not handle to ignore DEBUG.
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Reviewed-by: Benedikt Spranger <b.spranger@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Fix a spelling in the comment line.
s/memry/memory/p
This is on linux-next.
Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Currently the kvm-check-branches.sh script calculates the number of CPUs
and passes this to the kvm.sh --cpus command-line argument. This works,
but this commit saves a line by instead using the new kvm.sh --allcpus
command-line argument.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This fixes a typo. Before this, the AT_FDCWD macro would be defined
regardless of whether or not it's been defined before.
Signed-off-by: Samuel Hernandez <sam.hernandez.amador@gmail.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
If cur_ops->sync is NULL, rcu_torture_fwd_prog_nr() will nevertheless
attempt to call through it. This commit therefore flags cases where
neither need_resched() nor call_rcu() forward-progress testing
can be performed due to NULL function pointers, and also causes
rcu_torture_fwd_prog_nr() to take an early exit if cur_ops->sync()
is NULL.
Reported-by: Tom Rix <trix@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
When executing the LOCK06 locktorture scenario featuring percpu-rwsem,
the RCU callback rcu_sync_func() may still be pending after locktorture
module is removed. This can in turn lead to the following Oops:
BUG: unable to handle page fault for address: ffffffffc00eb920
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 6500a067 P4D 6500a067 PUD 6500c067 PMD 13a36c067 PTE 800000013691c163
Oops: 0000 [#1] PREEMPT SMP
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.9.0-rc5+ #4
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
RIP: 0010:rcu_cblist_dequeue+0x12/0x30
Call Trace:
<IRQ>
rcu_core+0x1b1/0x860
__do_softirq+0xfe/0x326
asm_call_on_stack+0x12/0x20
</IRQ>
do_softirq_own_stack+0x5f/0x80
irq_exit_rcu+0xaf/0xc0
sysvec_apic_timer_interrupt+0x2e/0xb0
asm_sysvec_apic_timer_interrupt+0x12/0x20
This commit avoids tis problem by adding an exit hook in lock_torture_ops
and using it to call percpu_free_rwsem() for percpu rwsem torture during
the module-cleanup function, thus ensuring that rcu_sync_func() completes
before module exits.
It is also necessary to call the exit hook if lock_torture_init()
fails half-way, so this commit also adds an ->init_called field in
lock_torture_cxt to indicate that exit hook, if present, must be called.
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
In virtual environments on systems with hardware assist, inter-processor
interrupts must do very different things based on whether the target
vCPU is running or not. This commit therefore enables torture-test
stuttering to better test these running/not-running transitions.
Suggested-by: Chris Mason <clm@fb.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This commit allows --build-only as a synonym for --buildonly, --kconfigs
for --kconfig, and --kmake-args for --kmake-arg.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
The rcu_torture_cleanup() function fails to NULL out the reader_tasks
pointer after freeing it and its fakewriter_tasks loop has redundant
braces. This commit therefore cleans these up.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
The "--duration <minutes>" has worked well for a very long time, but
it can be inconvenient to compute the minutes for (say) a 28-hour run.
It can also be annoying to have to let a simple boot test run for a full
minute. This commit therefore permits an "s" suffix to specify seconds,
"m" to specify minutes (which remains the default), "h" suffix to specify
hours, and "d" to specify days.
With this change, "--duration 5" still specifies that each scenario
run for five minutes, but "--duration 30s" runs for only 30 seconds,
"--duration 8h" runs for eight hours, and "--duration 2d" runs for
two days.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Currently, stutter_wait() will happily spin waiting for the stutter
interval to end even if the caller is running at a real-time priority
level. This could starve normal-priority tasks for no good reason. This
commit therefore drops the calling task's priority to SCHED_OTHER MAX_NICE
if stutter_wait() needs to wait. But when it waits, stutter_wait()
returns true, which allows the caller to restore the priority if needed.
Callers that were already running at SCHED_OTHER MAX_NICE obviously
do not need any changes, but this commit also restores priority for
higher-priority callers.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Although the rcutorture scripting now deals correctly with full-up
security-induced pointer obfuscation, it is still counter-productive for
kernel hackers who are analyzing console output. This commit therefore
sets the debug_boot_weak_hash kernel boot parameter, which enables
printing of weak-hashed pointers for torture-test runs.
Please note that this change applies only to runs initiated by the
kvm.sh scripting. If you are instead using modprobe and rmmod, it is
your responsibility to build and boot the underlying kernel to your taste.
Please note further that this change does not result in a security hole
in normal use. The rcutorture testing runs with a negligible userspace,
no networking, and no user interaction. Besides which, there is no data
of value that can be extracted from an rcutorture guest OS that could
not also be extracted from the host that this guest is running on.
Suggested-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
If an rcutorture torture-test run is given a bad kvm.sh argument, the
test will complain to the console, which is good. What is bad is that
from the user's perspective, it will just hang for the time specified
by the --duration argument. This commit therefore forces an immediate
kernel shutdown if a rcu_torture_init()-time error occurs, thus avoiding
the appearance of a hang. It also forces a console splat in this case
to clearly indicate the presence of an error.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Even when the kernel panics and qemu dies, runs with jitter enabled will
continue uselessly until the jitter.sh processes terminate. This can
be annoying if a planned one-hour run instead dies during boot.
This commit therefore kills the jitter.sh processes when the run ends
more than one minute prior to the termination time specified by the
kvm.sh --duration argument or its default.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
If an locktorture torture-test run is given a bad kvm.sh argument, the
test will complain to the console, which is good. What is bad is that
from the user's perspective, it will just hang for the time specified
by the --duration argument. This commit therefore forces an immediate
kernel shutdown if a lock_torture_init()-time error occurs, thus avoiding
the appearance of a hang. It also forces a console splat in this case
to clearly indicate the presence of an error.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Exclusive locks do not have readlock support, which means that a
locktorture run with the following module parameters will do nothing:
torture_type=mutex_lock nwriters_stress=0 nreaders_stress=1
This commit therefore rejects this combination for exclusive locks by
returning -EINVAL during module init.
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
The SRCU-u scenario expects to enable lockdep but to also disable the
CONFIG_PREEMPT_COUNT kconfig option. This no longer works. This commit
therefore instead enables lockdep in SRCU-t, which then allows SRCU-u
to disable CONFIG_PREEMPT_COUNT.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
If an refscale torture-test run is given a bad kvm.sh argument, the
test will complain to the console, which is good. What is bad is that
from the user's perspective, it will just hang for the time specified
by the --duration argument. This commit therefore forces an immediate
kernel shutdown if a ref_scale_init()-time error occurs, thus avoiding
the appearance of a hang. It also forces a console splat in this case
to clearly indicate the presence of an error.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
If an rcuscale torture-test run is given a bad kvm.sh argument, the
test will complain to the console, which is good. What is bad is that
from the user's perspective, it will just hang for the time specified
by the --duration argument. This commit therefore forces an immediate
kernel shutdown if a rcu_scale_init()-time error occurs, thus avoiding
the appearance of a hang. It also forces a console splat in this case
to clearly indicate the presence of an error.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
