If some abnormal users try lots of atomic write operations, f2fs is able to
produce pinned pages in the main memory which affects system performance.
This patch limits that as 20% over total memory size, and if f2fs reaches
to the limit, it will drop all the inmemory pages.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In ->umount, once we drop remained discard entries, we should not
set CP_TRIMMED_FLAG with another checkpoint.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds tracepoint to trace f2fs_remove_discard.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

__submit_discard_cmd may lead long latency due to exhaustion of I/O
request resource in block layer, so issuing all discard under cmd_lock
may lead to hangtask, in order to avoid that, let's reduce it's coverage.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

There are many different scenarios such as fstrim, umount, urgent or
background where we will issue discards, actually, they need use
different policy in aspect of io aware, discard granularity, delay
interval and so on. But now they just share one common discard policy,
so there will be race when changing policy in between these scenarios,
the interference of changing discard policy will be very serious.

This patch changes to split discard policy for different scenarios.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch wraps scattered optional parameters into discard policy as
below, later, with it we expect that we can adjust these parameters with
proper strategy in different scenario.

struct discard_policy {
	unsigned int min_interval;	/* used for candidates exist */
	unsigned int max_interval;	/* used for candidates not exist */
	unsigned int max_requests;	/* # of discards issued per round */
	unsigned int io_aware_gran;	/* minimum granularity discard not be aware of I/O */
	bool io_aware;			/* issue discard in idle time */
	bool sync;			/* submit discard with REQ_SYNC flag */
};

This patch doesn't change any logic of codes.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Fstrim intends to trim invalid blocks of filesystem only with specified
range and granularity, but actually, it will issue all previous cached
discard commands which may be out-of-range and be with unmatched
granularity, it's unneeded.

In order to fix above issues, this patch introduces new helps to support
to issue and wait discard in range and adds a new fstrim_list for tracking
in-flight discard from ->fstrim.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If f2fs manages multiple devices, in checkpoint, we need to issue flush
in those devices which contain dirty data/node in their cache before
we write checkpoint region, otherwise, filesystem metadata could be
corrupted if hitting SPO after checkpoint.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

When multiple device feature is enabled, during ->fsync we will issue
flush in all devices to make sure node/data of the file being persisted
into storage. But some flushes of device could be unneeded as file's
data may be not writebacked into those devices. So this patch adds and
manage bitmap per inode in global cache to indicate which device is
dirty and it needs to issue flush during ->fsync, hence, we could improve
performance of fsync in scenario of multiple device.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

As Ju Hyung Park reported:

"When 'fstrim' is called for manual trim, a BUG() can be triggered
randomly with this patch.

I'm seeing this issue on both x86 Desktop and arm64 Android phone.

On x86 Desktop, this was caused during Ubuntu boot-up. I have a
cronjob installed which calls 'fstrim -v /' during boot. On arm64
Android, this was caused during GC looping with 1ms gc_min_sleep_time
& gc_max_sleep_time."

Root cause of this issue is that f2fs_wait_discard_bios can only be
used by f2fs_put_super, because during put_super there must be no
other referrers, so it can ignore discard entry's reference count
when removing the entry, otherwise in other caller we will hit bug_on
in __remove_discard_cmd as there may be other issuer added reference
count in discard entry.

Thread A				Thread B
					- issue_discard_thread
- f2fs_ioc_fitrim
 - f2fs_trim_fs
  - f2fs_wait_discard_bios
   - __issue_discard_cmd
    - __submit_discard_cmd
					 - __wait_discard_cmd
					  - dc->ref++
					  - __wait_one_discard_bio
   - __wait_discard_cmd
    - __remove_discard_cmd
     - f2fs_bug_on(sbi, dc->ref)

Fixes: 969d1b18Reported-by: NJu Hyung Park <qkrwngud825@gmail.com>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Once we encounter I/O interruption during issuing discards, we will delay
long time before next round, but if system status is I/O idle during the
time, it may loses opportunity to issue discards. So this patch changes
to hurry up to issue discard after io interruption.

Besides, this patch also fixes to issue discards accurately with assigned
rate.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch activates SSR in gc_urgent mode.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In android, we'd better wait for fstrim completion instead of issuing the
discard commands asynchronous.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch renames functions regarding to buffer management via META_MAPPING
used for encrypted blocks especially. We can actually use them in generic way.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In scenario of remount_ro vs flush, after flush_thread exits in
->remount_fs, flusher will only clean up golbal issue_list, but
without waking up flushers waiting on that list, result in hang
related user threads.

In order to fix this issue, this patch enables the flusher to
take charge of issue_flush thread: executes merged flush command,
and wake up all sleeping flushers.

Fixes: 5eba8c5d ("f2fs: fix to access nullified flush_cmd_control pointer")
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Previously, we will miss merging flush command during fsync due to below
race condition:

Thread A 		Thread B		Thread C
- f2fs_issue_flush
 - atomic_read(&issing_flush)
			- f2fs_issue_flush
			 - atomic_read(&issing_flush)
						- f2fs_issue_flush
						 - atomic_read(&issing_flush)
  - atomic_inc(&issing_flush)
			  - atomic_inc(&issing_flush)
						  - atomic_inc(&issing_flush)
   - submit_flush_wait
			   - submit_flush_wait
						   - submit_flush_wait

It needs to use atomic_inc_return instead to avoid such race.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

allocate_segment_by_default is the only caller of change_curseg passing
@reuse with 'false', but commit 763bfe1b ("f2fs: remove reusing any
prefree segments") removes the calling, after that, @reuse in
change_curseg always be true, so, let's clean up the unneeded parameter.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch fixes to avoid needless wake ups.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch fixes to clear FI_HOT_DATA correctly in below path:
- error handling in f2fs_ioc_start_atomic_write
- after commit atomic write in f2fs_ioc_commit_atomic_write
- after drop atomic write in drop_inmem_pages
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In f2fs_issue_flush, due to out-of-order execution of CPU, wake_up can
be called before we insert issue_list, result in long latency of
wait_for_completion. Fix this by adding smp_mb() to force the order of
related codes.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

It's time to issue all the discard commands, if user sets the idle time.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This way we don't need a block_device structure to submit I/O.  The
block_device has different life time rules from the gendisk and
request_queue and is usually only available when the block device node
is open.  Other callers need to explicitly create one (e.g. the lightnvm
passthrough code, or the new nvme multipathing code).

For the actual I/O path all that we need is the gendisk, which exists
once per block device.  But given that the block layer also does
partition remapping we additionally need a partition index, which is
used for said remapping in generic_make_request.

Note that all the block drivers generally want request_queue or
sometimes the gendisk, so this removes a layer of indirection all
over the stack.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Commit d618ebaf ("f2fs: enable small discard by default") enables
f2fs to issue 4K size discard in real-time discard mode. However, issuing
smaller discard may cost more lifetime but releasing less free space in
flash device. Since f2fs has ability of separating hot/cold data and
garbage collection, we can expect that small-sized invalid region would
expand soon with OPU, deletion or garbage collection on valid datas, so
it's better to delay or skip issuing smaller size discards, it could help
to reduce overmuch consumption of IO bandwidth and lifetime of flash
storage.

This patch makes f2fs selectng 64K size as its default minimal
granularity, and issue discard with the size which is not smaller than
minimal granularity. Also it exposes discard granularity as sysfs entry
for configuration in different scenario.

Jaegeuk Kim:
 We must issue all the accumulated discard commands when fstrim is called.
 So, I've added pend_list_tag[] to indicate whether we should issue the
 commands or not. If tag sets P_ACTIVE or P_TRIM, we have to issue them.
 P_TRIM is set once at a time, given fstrim trigger.
 In addition, issue_discard_thread is calling too much due to the number of
 discard commands remaining in the pending list. I added a timer to control
 it likewise gc_thread.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

During atomic committing, if we encounter -ENOMEM in revoke path, it's
better to give a chance to retry revoking.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

The current size value is not correct and will miss bitmap check.
Signed-off-by: NYunlong Song <yunlong.song@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch enables inner app/fs io stats and introduces below virtual fs
nodes for exposing stats info:
/sys/fs/f2fs/<dev>/iostat_enable
/proc/fs/f2fs/<dev>/iostat_info
Signed-off-by: NChao Yu <yuchao0@huawei.com>
[Jaegeuk Kim: fix wrong stat assignment]
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Signed-off-by: NYunlong Song <yunlong.song@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

When cur_valid_map passes the f2fs_test_and_set(,clear)_bit test,
cur_valid_map_mir update is skipped unlikely, so fix it. The fix
now changes the mirror check together with cur_valid_map all the
time.
Signed-off-by: NYunlong Song <yunlong.song@huawei.com>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
[Jaegeuk Kim: Fix unused variable and add unlikely for corner condition.]
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds to support inode checksum in f2fs.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
[Jaegeuk Kim: fix verification flow]
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

When ->freeze_fs is called from lvm for doing snapshot, it needs to
make sure there will be no more changes in filesystem's data, however,
previously, background threads like GC thread wasn't aware of freezing,
so in environment with active background threads, data of snapshot
becomes unstable.

This patch fixes this issue by adding sb_{start,end}_intwrite in
below background threads:
- GC thread
- flush thread
- discard thread

Note that, don't use sb_start_intwrite() in gc_thread_func() due to:

generic/241 reports below bug:

 ======================================================
 WARNING: possible circular locking dependency detected
 4.13.0-rc1+ #32 Tainted: G           O
 ------------------------------------------------------
 f2fs_gc-250:0/22186 is trying to acquire lock:
  (&sbi->gc_mutex){+.+...}, at: [<f8fa7f0b>] f2fs_sync_fs+0x7b/0x1b0 [f2fs]

 but task is already holding lock:
  (sb_internal#2){++++.-}, at: [<f8fb5609>] gc_thread_func+0x159/0x4a0 [f2fs]

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> #2 (sb_internal#2){++++.-}:
        __lock_acquire+0x405/0x7b0
        lock_acquire+0xae/0x220
        __sb_start_write+0x11d/0x1f0
        f2fs_evict_inode+0x2d6/0x4e0 [f2fs]
        evict+0xa8/0x170
        iput+0x1fb/0x2c0
        f2fs_sync_inode_meta+0x3f/0xf0 [f2fs]
        write_checkpoint+0x1b1/0x750 [f2fs]
        f2fs_sync_fs+0x85/0x1b0 [f2fs]
        f2fs_do_sync_file.isra.24+0x137/0xa30 [f2fs]
        f2fs_sync_file+0x34/0x40 [f2fs]
        vfs_fsync_range+0x4a/0xa0
        do_fsync+0x3c/0x60
        SyS_fdatasync+0x15/0x20
        do_fast_syscall_32+0xa1/0x1b0
        entry_SYSENTER_32+0x4c/0x7b

 -> #1 (&sbi->cp_mutex){+.+...}:
        __lock_acquire+0x405/0x7b0
        lock_acquire+0xae/0x220
        __mutex_lock+0x4f/0x830
        mutex_lock_nested+0x25/0x30
        write_checkpoint+0x2f/0x750 [f2fs]
        f2fs_sync_fs+0x85/0x1b0 [f2fs]
        sync_filesystem+0x67/0x80
        generic_shutdown_super+0x27/0x100
        kill_block_super+0x22/0x50
        kill_f2fs_super+0x3a/0x40 [f2fs]
        deactivate_locked_super+0x3d/0x70
        deactivate_super+0x40/0x60
        cleanup_mnt+0x39/0x70
        __cleanup_mnt+0x10/0x20
        task_work_run+0x69/0x80
        exit_to_usermode_loop+0x57/0x92
        do_fast_syscall_32+0x18c/0x1b0
        entry_SYSENTER_32+0x4c/0x7b

 -> #0 (&sbi->gc_mutex){+.+...}:
        validate_chain.isra.36+0xc50/0xdb0
        __lock_acquire+0x405/0x7b0
        lock_acquire+0xae/0x220
        __mutex_lock+0x4f/0x830
        mutex_lock_nested+0x25/0x30
        f2fs_sync_fs+0x7b/0x1b0 [f2fs]
        f2fs_balance_fs_bg+0xb9/0x200 [f2fs]
        gc_thread_func+0x302/0x4a0 [f2fs]
        kthread+0xe9/0x120
        ret_from_fork+0x19/0x24

 other info that might help us debug this:

 Chain exists of:
   &sbi->gc_mutex --> &sbi->cp_mutex --> sb_internal#2

  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(sb_internal#2);
                                lock(&sbi->cp_mutex);
                                lock(sb_internal#2);
   lock(&sbi->gc_mutex);

  *** DEADLOCK ***

 1 lock held by f2fs_gc-250:0/22186:
  #0:  (sb_internal#2){++++.-}, at: [<f8fb5609>] gc_thread_func+0x159/0x4a0 [f2fs]

 stack backtrace:
 CPU: 2 PID: 22186 Comm: f2fs_gc-250:0 Tainted: G           O    4.13.0-rc1+ #32
 Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
 Call Trace:
  dump_stack+0x5f/0x92
  print_circular_bug+0x1b3/0x1bd
  validate_chain.isra.36+0xc50/0xdb0
  ? __this_cpu_preempt_check+0xf/0x20
  __lock_acquire+0x405/0x7b0
  lock_acquire+0xae/0x220
  ? f2fs_sync_fs+0x7b/0x1b0 [f2fs]
  __mutex_lock+0x4f/0x830
  ? f2fs_sync_fs+0x7b/0x1b0 [f2fs]
  mutex_lock_nested+0x25/0x30
  ? f2fs_sync_fs+0x7b/0x1b0 [f2fs]
  f2fs_sync_fs+0x7b/0x1b0 [f2fs]
  f2fs_balance_fs_bg+0xb9/0x200 [f2fs]
  gc_thread_func+0x302/0x4a0 [f2fs]
  ? preempt_schedule_common+0x2f/0x4d
  ? f2fs_gc+0x540/0x540 [f2fs]
  kthread+0xe9/0x120
  ? f2fs_gc+0x540/0x540 [f2fs]
  ? kthread_create_on_node+0x30/0x30
  ret_from_fork+0x19/0x24

The deadlock occurs in below condition:
GC Thread			Thread B
- sb_start_intwrite
				- f2fs_sync_file
				 - f2fs_sync_fs
				  - mutex_lock(&sbi->gc_mutex)
				   - write_checkpoint
				    - block_operations
				     - f2fs_sync_inode_meta
				      - iput
				       - sb_start_intwrite
 - mutex_lock(&sbi->gc_mutex)

Fix this by altering sb_start_intwrite to sb_start_write_trylock.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

It'd be better to retry writing atomic pages when we get -ENOMEM.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

After we introduce discard thread, discard command can be issued
concurrently with data allocating, this patch adds new function to
heck sit bitmap to ensure that userdata was invalid in which on-going
discard command covered.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch resolves kernel panic for xfstests/081, caused by recent f2fs_bug_on

 f2fs: add f2fs_bug_on in __remove_discard_cmd

For fixing, we will stop gc/discard thread in prior in ->kill_sb in order to
avoid referring and releasing race among them.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

create_flush_cmd_control will create redundant issue_flush_thread after each
remount with flush_merge option.
Signed-off-by: NYunlong Song <yunlong.song@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Recently, discard related codes have changed a lot, so add f2fs_bug_on to
detect potential bug.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In order to avoid copied codes.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Make sure number of entires doesn't exceed max journal size.

Cc: stable@vger.kernel.org
Signed-off-by: NJin Qian <jinqian@android.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Mount fs with option noflush_merge, boot failed for illegal address
fcc in function f2fs_issue_flush:

        if (!test_opt(sbi, FLUSH_MERGE)) {
                ret = submit_flush_wait(sbi);
                atomic_inc(&fcc->issued_flush);   ->  Here, fcc illegal
                return ret;
        }
Signed-off-by: NYunlei He <heyunlei@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

clear_prefree_segments() issues small discards after discarding full
segments. These small discards may not be section aligned, so not zone
aligned on a zoned block device, causing __f2fs_iissue_discard_zone() to fail.
Fix this by not issuing small discards for a volume mounted with the BLKZONED
feature enabled.

Cc: stable@vger.kernel.org
Signed-off-by: NDamien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Replace bi_error with a new bi_status to allow for a clear conversion.
Note that device mapper overloaded bi_error with a private value, which
we'll have to keep arround at least for now and thus propagate to a
proper blk_status_t value.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@fb.com>