With the help of previously added tracepoints we can now trace
report-zones, zone-write and zone-mgmt ops in null_blk_zoned.c.
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This patch adds two new tracpoints for null_blk_zoned.c that allows us
to trace report-zones, zone-mgmt-op and zone-write operations which has
direct effect on the zone condition state machine.
Also, we update drivers/block/Makefile so that new null_blk related
tracefiles can be compiled.
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add a helper to stringify the zone conditions. We use this helper in the
next patch to track zone conditions in tracepoints.
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull 5.7 NVMe updates from Keith.
* 'nvme-5.7-rc1' of git://git.infradead.org/nvme: (42 commits)
nvme: cleanup namespace identifier reporting in nvme_init_ns_head
nvme: rename __nvme_find_ns_head to nvme_find_ns_head
nvme: refactor nvme_identify_ns_descs error handling
nvme-tcp: Add warning on state change failure at nvme_tcp_setup_ctrl
nvme-rdma: Add warning on state change failure at nvme_rdma_setup_ctrl
nvme: Fix controller creation races with teardown flow
nvme: Make nvme_uninit_ctrl symmetric to nvme_init_ctrl
nvme: Fix ctrl use-after-free during sysfs deletion
nvme-pci: Re-order nvme_pci_free_ctrl
nvme: Remove unused return code from nvme_delete_ctrl_sync
nvme: Use nvme_state_terminal helper
nvme: release ida resources
nvme: Add compat_ioctl handler for NVME_IOCTL_SUBMIT_IO
nvmet-tcp: optimize tcp stack TX when data digest is used
nvme-fabrics: Use scnprintf() for avoiding potential buffer overflow
nvme-multipath: do not reset on unknown status
nvmet-rdma: allocate RW ctxs according to mdts
nvmet-rdma: Implement get_mdts controller op
nvmet: Add get_mdts op for controllers
nvme-pci: properly print controller address
...
Lift the common namespace identifier reporting between the shared
namespace and new nshead cases into common code. This also means
one less lock is held while doing I/O.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
There is no non __-prefixed version, so make the name a little more
readable.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Move the handling of an error into the function from the caller, and
only do it for an actual error on the admin command itself, not the
command parsing, as that should be enough to deal with devices claiming
a bogus version compliance.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
The transition to LIVE state should not fail in case of a new controller.
Moving to DELETING state before nvme_tcp_create_ctrl() allocates all the
resources may leads to NULL dereference at teardown flow (e.g., IO tagset,
admin_q, connect_q).
Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
The transition to LIVE state should not fail in case of a new controller.
Moving to DELETING state before nvme_tcp_create_ctrl() allocates all the
resources may leads to NULL dereference at teardown flow (e.g., IO tagset,
admin_q, connect_q).
Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Calling nvme_sysfs_delete() when the controller is in the middle of
creation may cause several bugs. If the controller is in NEW state we
remove delete_controller file and don't delete the controller. The user
will not be able to use nvme disconnect command on that controller again,
although the controller may be active. Other bugs may happen if the
controller is in the middle of create_ctrl callback and
nvme_do_delete_ctrl() starts. For example, freeing I/O tagset at
nvme_do_delete_ctrl() before it was allocated at create_ctrl callback.
To fix all those races don't allow the user to delete the controller
before it was fully created.
Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Put the ctrl reference count at nvme_uninit_ctrl as opposed to
nvme_init_ctrl which takes it. This decrease the reference count at the
core layer instead of decreasing it on each transport separately.
Also move the call of nvme_uninit_ctrl at PCI driver after calling to
nvme_release_prp_pools and nvme_dev_unmap, in order to put the reference
count after using the dev. This is safe because those functions use
nvme_dev which is freed only later at nvme_pci_free_ctrl.
Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
In case nvme_sysfs_delete() is called by the user before taking the ctrl
reference count, the ctrl may be freed during the creation and cause the
bug. Take the reference as soon as the controller is externally visible,
which is done by cdev_device_add() in nvme_init_ctrl(). Also take the
reference count at the core layer instead of taking it on each transport
separately.
Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Destroy the resources in the same order like in nvme_probe error flow to
improve code readability.
Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
The return code of nvme_delete_ctrl_sync is never used, so change it to
void.
Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Improve code readability.
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
ida instances allocate some internal memory in addition to the base
'struct ida'. Use ida_destroy() to release that memory at module_exit().
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Currently 32 bit application gets ENOTTY when it calls
compat_ioctl with NVME_IOCTL_SUBMIT_IO in 64 bit kernel.
The cause is that the results of sizeof(struct nvme_user_io),
which is used to define NVME_IOCTL_SUBMIT_IO,
are not same between 32 bit compiler and 64 bit compiler.
* 32 bit: the result of sizeof nvme_user_io is 44.
* 64 bit: the result of sizeof nvme_user_io is 48.
64 bit compiler seems to add 32 bit padding for multiple of 8 bytes.
This patch adds a compat_ioctl handler.
The handler replaces NVME_IOCTL_SUBMIT_IO32 with NVME_IOCTL_SUBMIT_IO
in case 32 bit application calls compat_ioctl for submit in 64 bit kernel.
Then, it calls nvme_ioctl as usual.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Masahiro Yamada (KIOXIA) <masahiro31.yamada@kioxia.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
If we have a 4-byte data digest to send to the wire, but we
have more data to send, set MSG_MORE to tell the stack
that more is coming.
Reviewed-by: Mark Wunderlich <mark.wunderlich@intel.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Since snprintf() returns the would-be-output size instead of the
actual output size, the succeeding calls may go beyond the given
buffer limit. Fix it by replacing with scnprintf().
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
The nvme multipath error handling defaults to controller reset if the
error is unknown. There are, however, no existing nvme status codes that
indicate a reset should be used, and resetting causes unnecessary
disruption to the rest of IO.
Change nvme's error handling to first check if failover should happen.
If not, let the normal error handling take over rather than reset the
controller.
Based-on-a-patch-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: John Meneghini <johnm@netapp.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Current nvmet-rdma code allocates MR pool budget based on queue size,
assuming both host and target use the same "max_pages_per_mr" count.
After limiting the mdts value for RDMA controllers, we know the factor
of maximum MR's per IO operation. Thus, make sure MR pool will be
sufficient for the required IO depth and IO size.
That is, say host's SQ size is 100, then the MR pool budget allocated
currently at target will also be 100 MRs. But 100 IO WRITE Requests
with 256 sg_count(IO size above 1MB) require 200 MRs when target's
"max_pages_per_mr" is 128.
Reported-by: Krishnamraju Eraparaju <krishna2@chelsio.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Set the maximal data transfer size to be 1MB (currently mdts is
unlimited). This will allow calculating the amount of MR's that
one ctrl should allocate to fulfill it's capabilities.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Some transports, such as RDMA, would like to set the Maximum Data
Transfer Size (MDTS) according to device/port/ctrl characteristics.
This will enable the transport to set the optimal MDTS according to
controller needs and device capabilities. Add a new nvmet transport
op that is called during ctrl identification. This will not effect
transports that don't implement this option. The return value of the new
op is according to the NVMe spec definition for MDTS.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Israel Rukshin <israelr@mellanox.com>
If we failed to receive data from the socket, don't try
to further process it, we will for sure be handling a queue
error at this point. While no issue was seen with the
current behavior thus far, its safer to cease socket processing
if we detected an error.
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Consolidate the request failure handling code to where
it is being fetched (nvme_tcp_try_send).
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>
MAXH2CDATA is not zero based. Also no reason to limit ourselves to
1M transfers as we can do more easily. Make this an arbitrary limit
of 16M.
Reported-by: Wenhua Liu <liuw@vmware.com>
Cc: stable@vger.kernel.org # v5.0+
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Currently, queue io_cpu assignment is done sequentially for default,
read and poll queues based on queue id. This causes miss-alignment between
context of CPU initiating I/O and the I/O worker thread processing
queued requests or completions.
Change to modify queue io_cpu assignment to take into account queue
maps offset. Each queue io_cpu will start at zero for each queue map.
This essentially aligns read/poll queues to start over the same range as
default queues.
Testing performed by Mark with:
- ram device (nvmet)
- single CPU core (pinned)
- 100% 4k reads
- engine io_uring (not using sq_thread option)
- hipri flag set
Micro-benchmark results show a net gain of:
- increase of 18%-29% in IOPs
- reduction of 16%-22% in average latency
- reduction of 7%-23% in 99.99% latency
Baseline:
========
QDepth/Batch | IOPs [k] | Avg. Lat [us] | 99.99% Lat [us]
-----------------------------------------------------------------
1/1 | 32.4 | 30.11 | 50.94
32/8 | 179 | 168.20 | 371
CPU alignment:
=============
QDepth/Batch | IOPs [k] | Avg. Lat [us] | 99.99% Lat [us]
-----------------------------------------------------------------
1/1 | 38.5 | 25.18 | 39.16
32/8 | 231 | 130.75 | 343
Reported-by: Mark Wunderlich <mark.wunderlich@intel.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>
The timeout handler can use the existing nvme_poll() if it needs to
check a polled queue, allowing nvme_poll_irqdisable() to handle only
irq driven queues for the remaining callers.
Signed-off-by: Keith Busch <kbusch@kernel.org>
Completion handling had been done in two steps: find all new completions
under a lock, then handle those completions outside the lock. This was
done to make the locked section as short as possible so that other
threads using the same lock wait less time.
The driver no longer shares locks during completion, and is in fact
lockless for interrupt driven queues, so the optimization no longer
serves its original purpose. Replace the two-pass completion queue
handler with a single pass that completes entries immediately.
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
The only user for tagged completion was for timeout handling. That user,
though, really only cares if the timed out command is completed, which
we can safely check within the timeout handler.
Remove the tag check to simplify completion handling.
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
For set feature command when setting up NVME_FEAT_NUM_QUEUES, check
Number of I/O Completion Queues Requested (NCQR) and Number of I/O
Submission Queues Requested (NSQR) before we proceed, for invalid values
(i.e. 65535) return an appropriate NVMe invalid field status.
Signed-off-by: Amit Engel <Amit.Engel@dell.com>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>
After initialization, nvme_wait_ready checks for readiness every 100ms,
even though the drive may be ready far sooner than that. This delays
system boot by hundreds of milliseconds. Reduce the delay, checking for
readiness every millisecond instead.
Boot-time tests on an AWS c5.12xlarge:
Before:
[ 0.546936] initcall nvme_init+0x0/0x5b returned 0 after 37 usecs
...
[ 0.764178] nvme nvme0: 2/0/0 default/read/poll queues
[ 0.768424] nvme0n1: p1
[ 0.774132] EXT4-fs (nvme0n1p1): mounted filesystem with ordered data mode. Opts: (null)
[ 0.774146] VFS: Mounted root (ext4 filesystem) on device 259:1.
...
[ 0.788141] Run /sbin/init as init process
After:
[ 0.537088] initcall nvme_init+0x0/0x5b returned 0 after 37 usecs
...
[ 0.543457] nvme nvme0: 2/0/0 default/read/poll queues
[ 0.548473] nvme0n1: p1
[ 0.554339] EXT4-fs (nvme0n1p1): mounted filesystem with ordered data mode. Opts: (null)
[ 0.554344] VFS: Mounted root (ext4 filesystem) on device 259:1.
...
[ 0.567931] Run /sbin/init as init process
Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Log the controller status to know more about issue if it
lies within kernel nvme subsytem or controller is unhealthy.
Signed-off-by: Rupesh Girase <rgirase@redhat.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulakrni@wdc.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
The function nvme_identify_ns_desc() has 3 levels of nesting which make
error message to exceeded > 80 char per line which is not aligned with
the kernel code standards and rest of the NVMe subsystem code.
Add a helper function to move the processing of the log when the
command is successful by reducing the nesting and keeping the
code < 80 char per line.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
I see no good reason for the "If unsure, say N" advice in the description
of the NVME_HWMON configuration option. It is not dangerous, it does
not select any other option, and has a fairly low overhead.
As the option is already not enabled by default, further suggesting
hesitant users to not enable it is not useful anyway. Unlike some other
options where the description alone may not be sufficient for users to
make a decision, NVME_HWMON is pretty simple to grasp in my opinion,
so just let the user do what they want.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
We allow userspace to connect with a custom hostid which is useful for
certain use-cases. However there is is no way to tell what is the hostid
used to connect to a given controller.
Expose this so userspace can correlate controllers based on hostid.
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
We allow userspace to connect with a custom hostnqn which is useful for
certain use-cases. However there is no way to tell what is the hostnqn
used to connect to a given controller.
Expose this so userspace can correlate controllers based on hostnqn.
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Commit 253a99d95d ("bcache: move macro btree() and btree_root()
into btree.h") makes two duplicated declaration into btree.h,
typedef int (btree_map_keys_fn)();
int bch_btree_map_keys();
The kbuild test robot <lkp@intel.com> detects and reports this
problem and this patch fixes it by removing the duplicated ones.
Fixes: 253a99d95d ("bcache: move macro btree() and btree_root() into btree.h")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The idea of this patch is from Davidlohr Bueso, he posts a patch
for bcache to optimize barrier usage for read-modify-write atomic
bitops. Indeed such optimization can also apply on other locations
where smp_mb() is used before or after an atomic operation.
This patch replaces smp_mb() with smp_mb__before_atomic() or
smp_mb__after_atomic() in btree.c and writeback.c, where it is used
to synchronize memory cache just earlier on other cores. Although
the locations are not on hot code path, it is always not bad to mkae
things a little better.
Signed-off-by: Coly Li <colyli@suse.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We can avoid the unnecessary barrier on non LL/SC architectures,
such as x86. Instead, use the smp_mb__after_atomic().
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Since snprintf() returns the would-be-output size instead of the
actual output size, the succeeding calls may go beyond the given
buffer limit. Fix it by replacing with scnprintf().
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When attaching a cached device (a.k.a backing device) to a cache
device, bch_sectors_dirty_init() is called to count dirty sectors
and stripes (see what bcache_dev_sectors_dirty_add() does) on the
cache device.
The counting is done by a single thread recursive function
bch_btree_map_keys() to iterate all the bcache btree nodes.
If the btree has huge number of nodes, bch_sectors_dirty_init() will
take quite long time. In my testing, if the registering cache set has
a existed UUID which matches a already registered cached device, the
automatical attachment during the registration may take more than
55 minutes. This is too long for waiting the bcache to work in real
deployment.
Fortunately when bch_sectors_dirty_init() is called, no other thread
will access the btree yet, it is safe to do a read-only parallelized
dirty sectors counting by multiple threads.
This patch tries to create multiple threads, and each thread tries to
one-by-one count dirty sectors from the sub-tree indexed by a root
node key which the thread fetched. After the sub-tree is counted, the
counting thread will continue to fetch another root node key, until
the fetched key is NULL. How many threads in parallel depends on
the number of keys from the btree root node, and the number of online
CPU core. The thread number will be the less number but no more than
BCH_DIRTY_INIT_THRD_MAX. If there are only 2 keys in root node, it
can only be 2x times faster by this patch. But if there are 10 keys
in the root node, with this patch it can be 10x times faster.
Signed-off-by: Coly Li <colyli@suse.de>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When registering a cache device, bch_btree_check() is called to check
all btree nodes, to make sure the btree is consistent and not
corrupted.
bch_btree_check() is recursively executed in a single thread, when there
are a lot of data cached and the btree is huge, it may take very long
time to check all the btree nodes. In my testing, I observed it took
around 50 minutes to finish bch_btree_check().
When checking the bcache btree nodes, the cache set is not running yet,
and indeed the whole tree is in read-only state, it is safe to create
multiple threads to check the btree in parallel.
This patch tries to create multiple threads, and each thread tries to
one-by-one check the sub-tree indexed by a key from the btree root node.
The parallel thread number depends on how many keys in the btree root
node. At most BCH_BTR_CHKTHREAD_MAX (64) threads can be created, but in
practice is should be min(cpu-number/2, root-node-keys-number).
Signed-off-by: Coly Li <colyli@suse.de>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This patch changes macro btree_root() and btree() to bcache_btree_root()
and bcache_btree(), to avoid potential generic name clash in future.
NOTE: for product kernel maintainers, this patch can be skipped if
you feel the rename stuffs introduce inconvenince to patch backport.
Suggested-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
In order to accelerate bcache registration speed, the macro btree()
and btree_root() will be referenced out of btree.c. This patch moves
them from btree.c into btree.h with other relative function declaration
in btree.h, for the following changes.
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertenly introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull MD fixes from Song.
* 'md-next' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/song/md:
block: keep bdi->io_pages in sync with max_sectors_kb for stacked devices
md: check arrays is suspended in mddev_detach before call quiesce operations
Field bdi->io_pages added in commit 9491ae4aad ("mm: don't cap request
size based on read-ahead setting") removes unneeded split of read requests.
Stacked drivers do not call blk_queue_max_hw_sectors(). Instead they set
limits of their devices by blk_set_stacking_limits() + disk_stack_limits().
Field bio->io_pages stays zero until user set max_sectors_kb via sysfs.
This patch updates io_pages after merging limits in disk_stack_limits().
Commit c6d6e9b0f6 ("dm: do not allow readahead to limit IO size") fixed
the same problem for device-mapper devices, this one fixes MD RAIDs.
Fixes: 9491ae4aad ("mm: don't cap request size based on read-ahead setting")
Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>
Reviewed-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Song Liu <songliubraving@fb.com>
