Add the *remount* handle of flush_merge option, so that the users
can enable flush_merge in the runtime, such as the underlying device
handles the cache_flush command relatively slowly.
Signed-off-by: NGu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

Enable flush_merge only in f2fs is not read-only, so does the mount
option show.
Signed-off-by: NGu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

Some storage devices show relatively high latencies to complete cache_flush
commands, even though their normal IO speed is prettry much high. In such
the case, it needs to merge cache_flush commands as much as possible to avoid
issuing them redundantly.
So, this patch introduces a mount option, "-o flush_merge", to mitigate such
the overhead.

If this option is enabled by user, F2FS merges the cache_flush commands and then
issues just one cache_flush on behalf of them. Once the single command is
finished, F2FS sends a completion signal to all the pending threads.

Note that, this option can be used under a workload consisting of very intensive
concurrent fsync calls, while the storage handles cache_flush commands slowly.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This patch introduce is_merged_page() to check whether current page is merged
in f2fs bio cache. When page is not in cache, we can avoid submitting bio cache,
resulting in having more chance to merge pages.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This patch introduces fi->i_sem to protect fi's info that includes xattr_ver,
pino, i_nlink.
This enables to remove i_mutex during f2fs_sync_file, resulting in performance
improvement when a number of fsync calls are triggered from many concurrent
threads.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This patch introduces ram_thresh, a sysfs entry, which controls the memory
footprint used by the free nid list and the nat cache.

Previously, the free nid list was controlled by MAX_FREE_NIDS, while the nat
cache was managed by NM_WOUT_THRESHOLD.
However, this approach cannot be applied dynamically according to the system.

So, this patch adds ram_thresh that users can specify the threshold, which is
in order of 1 / 1024.
For example, if the total ram size is 4GB and the value is set to 10 by default,
f2fs tries to control the number of free nids and nat caches not to consume over
10 * (4GB / 1024) = 10MB.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

Previously 'background_gc={on***,off***}' is being parsed as correct option,
with this patch we cloud fix the trivial bug in mount process.

Change log from v1:
 o need to check length of parameter suggested by Jaegeuk Kim.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

The original segment_info's show looks out-of-format:
cat /proc/fs/f2fs/loop0/segment_info
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 512
512 512 512 512 512 512 512 0 0 512
348 0 263 0 0 512 0 0 512 512
512 512 0 512 512 512 512 512 512 512
512 512 511 328 512 512 512 512 512 512
512 512 512 512 512 512 512 0 0 175

Let's fix this and show type for each segment.
cat /proc/fs/f2fs/loop0/segment_info
format: segment_type|valid_blocks
segment_type(0:HD, 1:WD, 2:CD, 3:HN, 4:WN, 5:CN)
0    2|0   1|0   0|0   0|0   0|0   0|0   0|0   0|0   0|0   0|0
10   0|0   0|0   0|0   0|0   0|0   0|0   0|0   0|0   0|0   0|0
20   0|0   0|0   0|0   0|0   0|0   0|0   0|0   0|0   0|0   0|0
30   0|0   0|0   0|0   0|0   0|0   0|0   0|0   0|0   0|0   0|0
40   0|0   0|0   0|0   0|0   0|0   0|0   0|0   0|0   0|0   0|0
50   3|0   3|0   3|0   3|0   3|0   3|0   3|0   0|0   3|0   3|0
60   3|0   3|0   3|0   3|0   3|0   3|0   3|0   3|0   3|0   3|512
70   3|512 3|512 3|512 3|512 3|512 3|512 3|512 3|0   3|0   3|512
80   3|0   3|0   3|0   3|0   3|0   3|512 3|0   3|0   3|512 3|512
90   3|512 0|512 3|274 0|512 0|512 0|512 0|512 0|512 0|512 3|512
100  3|512 0|512 3|511 0|328 3|512 0|512 0|512 3|512 0|512 0|512
110  0|512 0|512 0|512 0|512 0|512 0|512 0|512 5|0   4|0   3|512
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

Previously, the no-op "mount -o mount /dev/xxx" operation when the
file system is already mounted read-write causes an implied,
unconditional syncfs().  This seems pretty stupid, and it's certainly
documented or guaraunteed to do this, nor is it particularly useful,
except in the case where the file system was mounted rw and is getting
remounted read-only.

However, it's possible that there might be some file systems that are
actually depending on this behavior.  In most file systems, it's
probably fine to only call sync_filesystem() when transitioning from
read-write to read-only, and there are some file systems where this is
not needed at all (for example, for a pseudo-filesystem or something
like romfs).
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: linux-fsdevel@vger.kernel.org
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Evgeniy Dushistov <dushistov@mail.ru>
Cc: Jan Kara <jack@suse.cz>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Anders Larsen <al@alarsen.net>
Cc: Phillip Lougher <phillip@squashfs.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Cc: Petr Vandrovec <petr@vandrovec.name>
Cc: xfs@oss.sgi.com
Cc: linux-btrfs@vger.kernel.org
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Cc: codalist@coda.cs.cmu.edu
Cc: linux-ext4@vger.kernel.org
Cc: linux-f2fs-devel@lists.sourceforge.net
Cc: fuse-devel@lists.sourceforge.net
Cc: cluster-devel@redhat.com
Cc: linux-mtd@lists.infradead.org
Cc: jfs-discussion@lists.sourceforge.net
Cc: linux-nfs@vger.kernel.org
Cc: linux-nilfs@vger.kernel.org
Cc: linux-ntfs-dev@lists.sourceforge.net
Cc: ocfs2-devel@oss.oracle.com
Cc: reiserfs-devel@vger.kernel.org

Upper bound checking of ino should be added to f2fs_nfs_get_inode, so unneeded
process before do_read_inode in f2fs_iget could be avoided when ino is invalid.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

The original segment_info's show is a bit out-of-format:

[root@guz Demoes]# cat /proc/fs/f2fs/loop0/segment_info
0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
......
0 0 0 0 0 0 0 0 0 0
0 0 1 0 0 1 [root@guz Demoes]#

so we fix it here for better legibility.
[root@guz Demoes]# cat /proc/fs/f2fs/loop0/segment_info
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
......
0 0 0 0 0 0 0 0 0 0
0 0 1 0 0 1
[root@guz Demoes]#
Signed-off-by: NGu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

Signed-off-by: NGu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This patch adds an sysfs entry to control dir_level used by the large directory.

The description of this entry is:

 dir_level                    This parameter controls the directory level to
			      support large directory. If a directory has a
			      number of files, it can reduce the file lookup
			      latency by increasing this dir_level value.
			      Otherwise, it needs to decrease this value to
			      reduce the space overhead. The default value is 0.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

At the end of the recovery procedure, write_checkpoint is called and updates
the cp count which is managed by f2fs stat.
But, previously build_stat() is called after the recovery procedure, which
results in:

BUG: unable to handle kernel NULL pointer dereference at 000000000000012c
IP: [<ffffffffa03b1030>] write_checkpoint+0x720/0xbc0 [f2fs]
Call Trace:
 [<ffffffff810a6b44>] ? mark_held_locks+0x74/0x140
 [<ffffffff8109a3e0>] ? __init_waitqueue_head+0x60/0x60
 [<ffffffffa03bf036>] recover_fsync_data+0x656/0xf20 [f2fs]
 [<ffffffff812ee3eb>] ? security_d_instantiate+0x1b/0x30
 [<ffffffffa03aeb4d>] f2fs_fill_super+0x94d/0xa00 [f2fs]
 [<ffffffff811a9825>] mount_bdev+0x1a5/0x1f0
 [<ffffffff8114915e>] ? __get_free_pages+0xe/0x40
 [<ffffffffa03ae200>] ? f2fs_remount+0x130/0x130 [f2fs]
 [<ffffffffa03aa575>] f2fs_mount+0x15/0x20 [f2fs]
 [<ffffffff811aa713>] mount_fs+0x43/0x1b0
 [<ffffffff811c7124>] vfs_kern_mount+0x74/0x160
 [<ffffffff811c5cb1>] ? __get_fs_type+0x51/0x60
 [<ffffffff811c9727>] do_mount+0x237/0xb50
 [<ffffffff811c936a>] ? copy_mount_options+0x3a/0x170

So, this patche changes the order of recovery_fsync_data() and
f2fs_build_stats().
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

Fixed a variety of trivial checkpatch warnings.  The only delta should
be some minor formatting on log strings that were split / too long.
Signed-off-by: NChris Fries <cfries@motorola.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

Previously during SSR and GC, the maximum number of retrials to find a victim
segment was hard-coded by MAX_VICTIM_SEARCH, 4096 by default.

This number makes an effect on IO locality, when SSR mode is activated, which
results in performance fluctuation on some low-end devices.

If max_victim_search = 4, the victim will be searched like below.
("D" represents a dirty segment, and "*" indicates a selected victim segment.)

 D1 D2 D3 D4 D5 D6 D7 D8 D9
[   *       ]
      [   *    ]
            [         * ]
	                [ ....]

This patch adds a sysfs entry to control the number dynamically through:
  /sys/fs/f2fs/$dev/max_victim_search
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This patch introduces new sysfs entries for users to control the policy of
in-place-updates, namely IPU, in f2fs.

Sometimes f2fs suffers from performance degradation due to its out-of-place
update policy that produces many additional node block writes.
If the storage performance is very dependant on the amount of data writes
instead of IO patterns, we'd better drop this out-of-place update policy.

This patch suggests 5 polcies and their triggering conditions as follows.

[sysfs entry name = ipu_policy]

0: F2FS_IPU_FORCE       all the time,
1: F2FS_IPU_SSR         if SSR mode is activated,
2: F2FS_IPU_UTIL        if FS utilization is over threashold,
3: F2FS_IPU_SSR_UTIL    if SSR mode is activated and FS utilization is over
                        threashold,
4: F2FS_IPU_DISABLE    disable IPU. (=default option)

[sysfs entry name = min_ipu_util]

This parameter controls the threshold to trigger in-place-updates.
The number indicates percentage of the filesystem utilization, and used by
F2FS_IPU_UTIL and F2FS_IPU_SSR_UTIL policies.

For more details, see need_inplace_update() in segment.h.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

insmod f2fs.ko is failed after insmod and rmmod firstly.

$ sudo insmod fs/f2fs/f2fs.ko
insmod: error inserting 'fs/f2fs/f2fs.ko': -1 Cannot allocate memory

-- dmesg --
kmem_cache_sanity_check (free_nid): Cache name already exists.
Signed-off-by: NChangman Lee <cm224.lee@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This patch introduces f2fs_io_info to mitigate the complex parameter list.

struct f2fs_io_info {
	enum page_type type;		/* contains DATA/NODE/META/META_FLUSH */
	int rw;				/* contains R/RS/W/WS */
	int rw_flag;			/* contains REQ_META/REQ_PRIO */
}

1. f2fs_write_data_pages
 - DATA
 - WRITE_SYNC is set when wbc->WB_SYNC_ALL.

2. sync_node_pages
 - NODE
 - WRITE_SYNC all the time

3. sync_meta_pages
 - META
 - WRITE_SYNC all the time
 - REQ_META | REQ_PRIO all the time

 ** f2fs_submit_merged_bio() handles META_FLUSH.

4. ra_nat_pages, ra_sit_pages, ra_sum_pages
 - META
 - READ_SYNC

Cc: Fan Li <fanofcode.li@samsung.com>
Cc: Changman Lee <cm224.lee@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This patch adds unlikely() macro into the most of codes.
The basic rule is to add that when:
- checking unusual errors,
- checking page mappings,
- and the other unlikely conditions.

Change log from v1:
 - Don't add unlikely for the NULL test and error test: advised by Andi Kleen.

Cc: Chao Yu <chao2.yu@samsung.com>
Cc: Andi Kleen <andi@firstfloor.org>
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

Use inner macro GFP_F2FS_ZERO to instead of GFP_NOFS | __GFP_ZERO for
simplification of code.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

The recover_orphan_inodes() returns no error all the time, so we don't need to
check its errors.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
[Jaegeuk Kim: add description]
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

Add a mount option: inline_data. If the mount option is set,
data of New created small files can be stored in their inode.
Signed-off-by: NHuajun Li <huajun.li@intel.com>
Signed-off-by: NHaicheng Li <haicheng.li@linux.intel.com>
Signed-off-by: NWeihong Xu <weihong.xu@intel.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

For better read performance, we add a new function to support for merging
contiguous read as the one for write.

v1-->v2:
 o add declarations here as Gu Zheng suggested.
 o use new structure f2fs_bio_info introduced by Jaegeuk Kim.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Acked-by: NGu Zheng <guz.fnst@cn.fujitsu.com>

The f2fs has three bio types, NODE, DATA, and META, and manages some data
structures per each bio types.

The codes are a little bit messy, thus, this patch introduces a bio array
which groups individual data structures as follows.

struct f2fs_bio_info {
	struct bio *bio;		/* bios to merge */
	sector_t last_block_in_bio;	/* last block number */
	struct mutex io_mutex;		/* mutex for bio */
};

struct f2fs_sb_info {
	...
	struct f2fs_bio_info write_io[NR_PAGE_TYPE];	/* for write bios */
	...
};

The code changes from this new data structure are trivial.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This patch removes an unnecessary semaphore (i.e., sbi->bio_sem).
There is no reason to use the semaphore when f2fs submits read and write IOs.
Instead, let's use a write mutex and cover the sbi->bio[] by the lock.

Change log from v1:
 o split write_mutex suggested by Chao Yu

Chao described,
"All DATA/NODE/META bio buffers in superblock is protected by
'sbi->write_mutex', but each bio buffer area is independent, So we
should split write_mutex to three for DATA/NODE/META."
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

If frequent small discards are issued to the device, the performance would
be degraded significantly.
So, this patch adds a sysfs entry to control the number of discards to be
issued during a checkpoint procedure.

By default, f2fs does not issue any small discards, which means max_discards
is zero.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This patch adds a slab cache entry for small discards.

Each entry consists of:

struct discard_entry {
	struct list_head list;	/* list head */
	block_t blkaddr;	/* block address to be discarded */
	int len;		/* # of consecutive blocks of the discard */
};
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

If we failed to init&add kobject when fill_super, stats info and proc object of
f2fs will not be released.
We should free them before we finish fill_super.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

use genernal method supported by kernel

 o changes from v1
   If any waiter exists at end io, wake up it.
Signed-off-by: NChangman Lee <cm224.lee@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This patch adds a control method in sysfs to reclaim prefree segments.
Signed-off-by: NChangman Lee <cm224.lee@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

Signed-off-by: NHaicheng Li <haicheng.li@linux.intel.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

Introduce function read_raw_super_block() to hide reading raw super block and
the retry routine if the first sb is invalid.
Signed-off-by: NGu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This patch removes the logic previously introduced to address the starvation
on cp_rwsem.

One potential there-in bug is that we should cover the wait.list with spin_lock,
but the previous code broke this rule.

And, actually current rwsem handles this starvation issue reasonably, so that we
didn't need to do this before neither.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

During the f2fs_put_super procedure, we don't need to conduct checkpoint all
the time, since we don't need to do that if superblock is clean.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

The current f2fs code errors if the xattr or acl options are passed when
remounting.  This is important in a typical scenario where f2fs is mounted
as a "ro" root file-system by the boot loader and then the init process wants
to remount it "rw" with the "remount,rw" option.
Signed-off-by: NKelly Anderson <kelly@xilka.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

The fs_locks is used to block other ops(ex, recovery) when doing checkpoint.
And each other operate routine(besides checkpoint) needs to acquire a fs_lock,
there is a terrible problem here, if these are too many concurrency threads acquiring
fs_lock, so that they will block each other and may lead to some performance problem,
but this is not the phenomenon we want to see.
Though there are some optimization patches introduced to enhance the usage of fs_lock,
but the thorough solution is using a *rw_sem* to replace the fs_lock.
Checkpoint routine takes write_sem, and other ops take read_sem, so that we can block
other ops(ex, recovery) when doing checkpoint, and other ops will not disturb each other,
this can avoid the problem described above completely.
Because of the weakness of rw_sem, the above change may introduce a potential problem
that the checkpoint thread might get starved if other threads are intensively locking
the read semaphore for I/O.(Pointed out by Xu Jin)
In order to avoid this, a wait_list is introduced, the appending read semaphore ops
will be dropped into the wait_list if checkpoint thread is waiting for write semaphore,
and will be waked up when checkpoint thread gives up write semaphore.
Thanks to Kim's previous review and test, and will be very glad to see other guys'
performance tests about this patch.

V2:
  -fix the potential starvation problem.
  -use more suitable func name suggested by Xu Jin.
Signed-off-by: NGu Zheng <guz.fnst@cn.fujitsu.com>
[Jaegeuk Kim: adjust minor coding standard]
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This patch enables the number of direct pointers inside on-disk inode block to
be changed dynamically according to the size of inline xattr space.

The number of direct pointers, ADDRS_PER_INODE, can be changed only if the file
has inline xattr flag.

The number of direct pointers that will be used by inline xattrs is defined as
F2FS_INLINE_XATTR_ADDRS.
Current patch assigns F2FS_INLINE_XATTR_ADDRS to 0 temporarily.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This patch adds basic inode flags for inline xattrs, F2FS_INLINE_XATTR,
and add a mount option, inline_xattr, which is enabled when xattr is set.

If the mount option is enabled, all the files are marked with the inline_xattrs
flag.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

Fix to return -ENOMEM in the kset create and add error handling
case instead of 0, as done elsewhere in this function.

Introduced by commit b59d0bae.
(f2fs: add sysfs support for controlling the gc_thread)
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: NNamjae Jeon <namjae.jeon@samsung.com>
[Jaegeuk Kim: merge the patch with previous modification]
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>