In this patch, we add a new sysfs interface, with it, we can control
number of reserved blocks in system which could not be used by user,
it enable f2fs to let user to configure for adjusting over-provision
ratio dynamically instead of changing it by mkfs.

So we can expect it will help to reserve more free space for relieving
GC in both filesystem and flash device.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds f2fs_ioc_gc_range() to move blocks located in the given
range.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Both in memory or on disk, generic filesystems record i_blocks with
512bytes sized sector count, also VFS sub module such as disk quota
follows this rule, but f2fs records it with 4096bytes sized block
count, this difference leads to that once we use dquota's function
which inc/dec iblocks, it will make i_blocks of f2fs being inconsistent
between in memory and on disk.

In order to resolve this issue, this patch changes to make in-memory
i_blocks of f2fs recording sector count instead of block count,
meanwhile leaving on-disk i_blocks recording block count.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Codes related to sysfs and procfs are dispersive and mixed with sb
related codes, but actually these codes are independent from others,
so split them from super.c, and reorgnize and manger them in sysfs.c.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Currently in F2FS, page faults and operations that truncate the pagecahe
or data blocks, are completely unsynchronized. This can result in page
fault faulting in a page into a range that we are changing after
truncating, and thus we can end up with a page mapped to disk blocks that
will be shortly freed. Filesystem corruption will shortly follow.

This patch fixes the problem by creating new rw semaphore i_mmap_sem in
f2fs_inode_info and grab it for functions removing blocks from extent tree
and for read over page faults. The mechanism is similar to that in ext4.
Signed-off-by: NQiuyang Sun <sunqiuyang@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Serialize data/node IOs by using fifo list instead of mutex lock,
it will help to enhance concurrency of f2fs, meanwhile keeping LFS
IO semantics.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Split wio_mutex to adjust different temperature bio cache.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Currently, if we do get_node_of_data before f2fs_lock_op, there may be dead lock
as follows, where process A would be in infinite loop, and B will NOT be awaked.

Process A(cp):            Process B:
f2fs_lock_all(sbi)
                        get_dnode_of_data <---- lock dn.node_page
flush_nodes             f2fs_lock_op

So, this patch adds f2fs_trylock_op to avoid f2fs_lock_op done by IPU.
Signed-off-by: NHou Pengyang <houpengyang@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Split DATA/NODE type bio cache according to different temperature,
so write IOs with the same temperature can be merged in corresponding
bio cache as much as possible, otherwise, different temperature write
IOs submitting into one bio cache will always cause split of bio.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Merged IO flow doesn't need to care about read IOs.

f2fs_submit_merged_bio -> f2fs_submit_merged_write
f2fs_submit_merged_bios -> f2fs_submit_merged_writes
f2fs_submit_merged_bio_cond -> f2fs_submit_merged_write_cond
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If user has no key under an encrypted dir, fscrypt gives digested dentries.
Previously, when looking up a dentry, f2fs only checks its hash value with
first 4 bytes of the digested dentry, which didn't handle hash collisions fully.
This patch enhances to check entire dentry bytes likewise ext4.

Eric reported how to reproduce this issue by:

 # seq -f "edir/abcdefghijklmnopqrstuvwxyz012345%.0f" 100000 | xargs touch
 # find edir -type f | xargs stat -c %i | sort | uniq | wc -l
100000
 # sync
 # echo 3 > /proc/sys/vm/drop_caches
 # keyctl new_session
 # find edir -type f | xargs stat -c %i | sort | uniq | wc -l
99999

Cc: <stable@vger.kernel.org>
Reported-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>
(fixed f2fs_dentry_hash() to work even when the hash is 0)
Signed-off-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

This patch adds an entry in f2fs/status to show # of available nids.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Introduce CP_TRIMMED_FLAG to indicate all invalid block were trimmed
before umount, so once we do mount with image which contain the flag,
we don't record invalid blocks as undiscard one, when fstrim is being
triggered, we can avoid issuing redundant discard commands.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Change to use different bits of cpc->reason to indicate different status,
so cpc->reason can indicate more than one reason.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

We don't need to rewrite the page under cp_rwsem and dnode locks.
Signed-off-by: NHou Pengyang <houpengyang@huawei.com>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In order to shrink size of struct discard_cmd, change variable type of
@state in struct discard_cmd from int to unsigned char.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Previously, with protection of cmd_lock, we will wait for end io of
discard command which potentially may lead long latency, making worse
concurrency.

So, in this patch, we try to add reference into discard entry to prevent
the entry being released by other thread, then we can avoid holding
global cmd_lock during waiting discard to finish.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch start to enable 4K granularity small discard by default
when realtime discard is on, so, in seriously fragmented space,
small size discard can be issued in time to avoid useless storage
space occupying of invalid filesystem's data, then performance of
flash storage can be recovered.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

With a recent addition of f2fs_lookup_extent_tree(), we get a warning about
the use of empty macros:

fs/f2fs/extent_cache.c: In function 'f2fs_lookup_extent_tree':
fs/f2fs/extent_cache.c:358:32: error: suggest braces around empty body in an 'else' statement [-Werror=empty-body]
   stat_inc_rbtree_node_hit(sbi);

A good way to avoid the warning and make the code more robust is to define
all no-op macros as 'do { } while (0)'.

Fixes: 54c2258c ("f2fs: extract rb-tree operation infrastructure")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Reivewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch fixes wrong _IOW usage.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds an ioctl to flush data in faster device to cold area. User can
give device number and number of segments to move. It doesn't move it if there
is only one device.

The parameter looks like:

struct f2fs_flush_device {
	u32 dev_num;		/* device number to flush */
	u32 segments;		/* # of segments to flush */
};
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds to account undiscard blocks.
Signed-off-by: NChao Yu <yuchao0@huawei.com>

For IPU writes, there won't be any udpates in dnode page since we
will reuse old block address instead of allocating new one, so we
don't need to lock cp_rwsem during IPU IO submitting.
Signed-off-by: NChao Yu <yuchao0@huawei.com>

Introduce __check_rb_tree_consistence to check consistence of rb-tree
based discard cache in runtime.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Keep issuing big size discard in prior instead of the one with random
size, so that we expect that it will help to:
- be quick to recycle unused large space in flash storage device.
- give a chance for
  a) wait to merge small piece discards into bigger one, or
  b) avoid issuing discards while they have being reallocated by SSR.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Avoid long variable name in discard_cmd_control structure, no logic
change.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Introduce rb-tree based discard cache infrastructure to speed up lookup and
merge operation of discard entry.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
[Jaegeuk Kim: initialize dc to avoid build warning]
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

rb-tree lookup/update functions are deeply coupled into extent cache
codes, it's very hard to reuse these basic functions, this patch
extracts common rb-tree operation infrastructure for latter reusing.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch cleans several macros by introducing:
- BLKS_PER_SEC
- GET_SEC_FROM_SEG
- GET_SEG_FROM_SEC
- GET_ZONE_FROM_SEC
- GET_ZONE_FROM_SEG
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Add braces around variables used within macros for those make sense
to do it. Many of the macros in f2fs already do this. What this commit
doesn't do is anything that changes line# as a result of adding braces,
which usually affects the binary via __LINE__.

Confirmed no diff in fs/f2fs/f2fs.ko before/after this commit on x86_64,
to make sure this has no functional change as well as there's been no
unexpected side effect due to callers' arithmetics within the existing
code.
Signed-off-by: NTomohiro Kusumi <tkusumi@tuxera.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Split f2fs_wait_discard_bios from f2fs_wait_discard_bio, just for cleanup,
no logic change.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Split discard_cmd_list to discard_{pend,wait}_list, so while sending/waiting
discard command, we can avoid traversing unneeded entries in original list.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Since callers statically know which type to use, make_dentry_ptr()
can simply be splitted into two inline functions. This way, the code
has less inlined, fewer arguments, and no cast.
Signed-off-by: NTomohiro Kusumi <tkusumi@tuxera.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch tries to split in-place-update bios from sequential bios.
Suggested-by: NYunlei He <heyunlei@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If two threads try to flush dirty pages in different inodes respectively,
f2fs_write_data_pages() will produce WRITE and WRITE_SYNC one at a time,
resulting in a lot of 4KB seperated IOs.

So, this patch gives higher priority to WB_SYNC_ALL IOs and gathers write
IOs with a big WRITE_SYNC'ed bio.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

It would better split small and large IOs separately in order to get more
consecutive big writes.

The default threshold is set to 64KB, but configurable by sysfs/min_hot_blocks.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch changes to use bitmap instead of extent in struct discard_entry
to indicate discard range in one segment, for fragmented space, this
implementation can save memory footprint.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Adds to count discard command entry and show the number in debugfs,
also fix to add cost of discard command cache into total comsumed
memory footprint.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Show historical count of flush command and discard command.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch allow write data to normal file when writting
new checkpoint.

We relax three limitations for write_begin path:
1. data allocation
2. node allocation
3. variables in checkpoint
Signed-off-by: NYunlei He <heyunlei@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>