Use sbi->blocks_per_seg directly to avoid unnecessary calculation when using
1 << sbi->log_blocks_per_seg.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Once f2fs_gc is done, wait_ms is changed once more.
So, its tracepoint would be located after it.
Reported-by: NHe YunLei <heyunlei@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

 different competitors

Since we use different page cache (normally inode's page cache for R/W
and meta inode's page cache for GC) to cache the same physical block
which is belong to an encrypted inode. Writeback of these two page
cache should be exclusive, but now we didn't handle writeback state
well, so there may be potential racing problem:

a)
kworker:				f2fs_gc:
 - f2fs_write_data_pages
  - f2fs_write_data_page
   - do_write_data_page
    - write_data_page
     - f2fs_submit_page_mbio
(page#1 in inode's page cache was queued
in f2fs bio cache, and be ready to write
to new blkaddr)
					 - gc_data_segment
					  - move_encrypted_block
					   - pagecache_get_page
					(page#2 in meta inode's page cache
					was cached with the invalid datas
					of physical block located in new
					blkaddr)
					   - f2fs_submit_page_mbio
					(page#1 was submitted, later, page#2
					with invalid data will be submitted)

b)
f2fs_gc:
 - gc_data_segment
  - move_encrypted_block
   - f2fs_submit_page_mbio
(page#1 in meta inode's page cache was
queued in f2fs bio cache, and be ready
to write to new blkaddr)
					user thread:
					 - f2fs_write_begin
					  - f2fs_submit_page_bio
					(we submit the request to block layer
					to update page#2 in inode's page cache
					with physical block located in new
					blkaddr, so here we may read gabbage
					data from new blkaddr since GC hasn't
					writebacked the page#1 yet)

This patch fixes above potential racing problem for encrypted inode.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Now, we use ra_meta_pages to reads continuous physical blocks as much as
possible to improve performance of following reads. However, ra_meta_pages
uses a synchronous readahead approach by submitting bio with READ, as READ
is with high priority, it can not be used in the case of preloading blocks,
and it's not sure when these RAed pages will be used.

This patch supports asynchronous readahead in ra_meta_pages by tagging bio
with READA flag in order to allow preloading.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

For normal inodes, their pages are allocated with __GFP_FS, which can cause
filesystem calls when reclaiming memory.
This can incur a dead lock condition accordingly.

So, this patch addresses this problem by introducing
f2fs_grab_cache_page(.., bool for_write), which calls
grab_cache_page_write_begin() with AOP_FLAG_NOFS.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch introduces a tracepoint to monitor background gc behaviors.
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch introduce background_gc=sync enabling synchronous cleaning in
background.
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch drops in batches gc triggered through ioctl, since user
can easily control the gc by designing the loop around the ->ioctl.

We support synchronous gc by forcing using FG_GC in f2fs_gc, so with
it, user can make sure that in this round all blocks gced were
persistent in the device until ioctl returned.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

When searching victim during gc, if there are no dirty segments in
filesystem, we will still take the time to search the whole dirty segment
map, it's not needed, it's better to skip in this condition.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

When doing gc, we search a victim in dirty map, starting from position of
last victim, we will reset the current searching position until we touch
the end of dirty map, and then search the whole diryt map. So sometimes we
will search the range [victim, last] twice, it's redundant, this patch
avoids this issue.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If we do not call get_victim first, we cannot get a new victim for retrial
path.
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch fixes to maintain the right section count freed in garbage
collecting when triggering a foreground gc.

Besides, when a foreground gc is running on current selected section, once
we fail to gc one segment, it's better to abandon gcing the left segments
in current section, because anyway we will select next victim for
foreground gc, so gc on the left segments in previous section will become
overhead and also cause the long latency for caller.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If FG_GC failed to reclaim one section, let's retry with another section
from the start, since we can get anoterh good candidate.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If node blocks were already moved, we don't need to move them again.
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

We should avoid needless checkpoints when there is no dirty and prefree segment.
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

That encrypted page is used temporarily, so we don't need to mark it accessed.
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This makes the function check_dnode have a return type of bool
due to this particular function only ever returning either one
or zero as its return value and changes the name of the function
to is_alive in order to better explain this function's intended
work of checking if a dnode is still in use by the filesystem.
Signed-off-by: NNicholas Krause <xerofoify@gmail.com>
[Jaegeuk Kim: change the return value check for the renamed function]
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

The cgroup attaches inode->i_wb via mark_inode_dirty and when set_page_writeback
is called, __inc_wb_stat() updates i_wb's stat.

So, we need to explicitly call set_page_dirty->__mark_inode_dirty in prior to
any writebacking pages.

This patch should resolve the following kernel panic reported by Andreas Reis.

https://bugzilla.kernel.org/show_bug.cgi?id=101801

--- Comment #2 from Andreas Reis <andreas.reis@gmail.com> ---
BUG: unable to handle kernel NULL pointer dereference at 00000000000000a8
IP: [<ffffffff8149deea>] __percpu_counter_add+0x1a/0x90
PGD 2951ff067 PUD 2df43f067 PMD 0
Oops: 0000 [#1] PREEMPT SMP
Modules linked in:
CPU: 7 PID: 10356 Comm: gcc Tainted: G        W       4.2.0-1-cu #1
Hardware name: Gigabyte Technology Co., Ltd. G1.Sniper M5/G1.Sniper M5, BIOS
T01 02/03/2015
task: ffff880295044f80 ti: ffff880295140000 task.ti: ffff880295140000
RIP: 0010:[<ffffffff8149deea>]  [<ffffffff8149deea>]
__percpu_counter_add+0x1a/0x90
RSP: 0018:ffff880295143ac8  EFLAGS: 00010082
RAX: 0000000000000003 RBX: ffffea000a526d40 RCX: 0000000000000001
RDX: 0000000000000020 RSI: 0000000000000001 RDI: 0000000000000088
RBP: ffff880295143ae8 R08: 0000000000000000 R09: ffff88008f69bb30
R10: 00000000fffffffa R11: 0000000000000000 R12: 0000000000000088
R13: 0000000000000001 R14: ffff88041d099000 R15: ffff880084a205d0
FS:  00007f8549374700(0000) GS:ffff88042f3c0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000000a8 CR3: 000000033e1d5000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 0000000000000000 ffffea000a526d40 ffff880084a20738 ffff880084a20750
 ffff880295143b48 ffffffff811cc91e ffff880000000000 0000000000000296
 0000000000000000 ffff880417090198 0000000000000000 ffffea000a526d40
Call Trace:
 [<ffffffff811cc91e>] __test_set_page_writeback+0xde/0x1d0
 [<ffffffff813fee87>] do_write_data_page+0xe7/0x3a0
 [<ffffffff813faeea>] gc_data_segment+0x5aa/0x640
 [<ffffffff813fb0b8>] do_garbage_collect+0x138/0x150
 [<ffffffff813fb3fe>] f2fs_gc+0x1be/0x3e0
 [<ffffffff81405541>] f2fs_balance_fs+0x81/0x90
 [<ffffffff813ee357>] f2fs_unlink+0x47/0x1d0
 [<ffffffff81239329>] vfs_unlink+0x109/0x1b0
 [<ffffffff8123e3d7>] do_unlinkat+0x287/0x2c0
 [<ffffffff8123ebc6>] SyS_unlink+0x16/0x20
 [<ffffffff81942e2e>] entry_SYSCALL_64_fastpath+0x12/0x71
Code: 41 5e 5d c3 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 55 49
89 f5 41 54 49 89 fc 53 48 83 ec 08 65 ff 05 e6 d9 b6 7e <48> 8b 47 20 48 63 ca
65 8b 18 48 63 db 48 01 f3 48 39 cb 7d 0a
RIP  [<ffffffff8149deea>] __percpu_counter_add+0x1a/0x90
 RSP <ffff880295143ac8>
CR2: 00000000000000a8
---[ end trace 5132449a58ed93a3 ]---
note: gcc[10356] exited with preempt_count 2
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch fixes some missing error handlers.
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In f2fs_gc:                      In f2fs_replace_block:
 - lock_page(sum_page)
  - check_valid_map()            - mutex_lock(sentry_lock)
   - mutex_lock(sentry_lock)     - change_curseg()
                                  - lock_page(sum_page)

This patch fixes the deadlock condition.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds encryption support in read and write paths.

Note that, in f2fs, we need to consider cleaning operation.
In cleaning procedure, we must avoid encrypting and decrypting written blocks.
So, this patch implements move_encrypted_block().
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch splits find_data_page as follows.

1. f2fs_gc
 - use get_read_data_page() with read only

2. find_in_level
 - use find_data_page without locked page

3. truncate_partial_page
 - In the case cache_only mode, just drop cached page.
 - Ohterwise, use get_lock_data_page() and guarantee to truncate
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch moves getting victim page into move_data_page.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds f2fs_sb_info and page pointers in f2fs_io_info structure.
With this change, we can reduce a lot of parameters for IO functions.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch is for looking into gc performance of f2fs in detail.
Signed-off-by: NChangman Lee <cm224.lee@samsung.com>
[Jaegeuk Kim: fix build errors]
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds FASTBOOT flag into checkpoint as follows.

 - CP_UMOUNT_FLAG is set when system is umounted.
 - CP_FASTBOOT_FLAG is set when intermediate checkpoint having node summaries
   was done.

So, if you get CP_UMOUNT_FLAG from checkpoint, the system was umounted cleanly.
Instead, if there was sudden-power-off, you can get CP_FASTBOOT_FLAG or nothing.
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Use pointer parameter @wait to pass result in {in,de}create_sleep_time for
cleanup.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

No modification in functionality, just clean codes with f2fs_radix_tree_insert.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

There are two slab cache inode_entry_slab and winode_slab using the same
structure as below:

struct dir_inode_entry {
	struct list_head list;	/* list head */
	struct inode *inode;	/* vfs inode pointer */
};

struct inode_entry {
	struct list_head list;
	struct inode *inode;
};

It's a little waste that the two cache can not share their memory space for each
other.
So in this patch we remove one redundant winode_slab slab cache, then use more
universal name struct inode_entry as remaining data structure name of slab,
finally we reuse the inode_entry_slab to store dirty dir item and gc item for
more effective.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch revists retrial paths in f2fs.
The basic idea is to use cond_resched instead of retrying from the very early
stage.
Suggested-by: NGu Zheng <guz.fnst@cn.fujitsu.com>
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch tries to fix:

 BUG: using smp_processor_id() in preemptible [00000000] code: f2fs_gc-254:0/384
  (radix_tree_node_alloc+0x14/0x74) from [<c033d8a0>] (radix_tree_insert+0x110/0x200)
  (radix_tree_insert+0x110/0x200) from [<c02e8264>] (gc_data_segment+0x340/0x52c)
  (gc_data_segment+0x340/0x52c) from [<c02e8658>] (f2fs_gc+0x208/0x400)
  (f2fs_gc+0x208/0x400) from [<c02e8a98>] (gc_thread_func+0x248/0x28c)
  (gc_thread_func+0x248/0x28c) from [<c0139944>] (kthread+0xa0/0xac)
  (kthread+0xa0/0xac) from [<c0105ef8>] (ret_from_fork+0x14/0x3c)

The reason is that f2fs calls radix_tree_insert under enabled preemption.
So, before calling it, we need to call radix_tree_preload.

Otherwise, we should use _GFP_WAIT for the radix tree, and use mutex or
semaphore to cover the radix tree operations.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If there are many inodes that have data blocks in victim segment,
it takes long time to find a inode in gc_inode list.
Let's use radix_tree to reduce lookup time.
Signed-off-by: NChangman Lee <cm224.lee@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Little cleanup to distinguish each phase easily
Signed-off-by: NChangman Lee <cm224.lee@samsung.com>
[Jaegeuk Kim: modify indentation for code readability]
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In f2fs_remount, we will stop gc thread and set need_restart_gc as true when new
option is set without BG_GC, then if any error occurred in the following
procedure, we can restore to start the gc thread.
But after that, We will fail to restore gc thread in start_gc_thread as BG_GC is
not set in new option, so we'd better move this condition judgment out of
start_gc_thread to fix this issue.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If a system wants to reduce the booting time as a top priority, now we can
use a mount option, -o fastboot.
With this option, f2fs conducts a little bit slow write_checkpoint, but
it can avoid the node page reads during the next mount time.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Remove the unneeded argument 'type' from __get_victim, use
NO_CHECK_TYPE directly when calling v_ops->get_victim().
Signed-off-by: NGu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch cleans up the existing and new macros for readability.

Rule is like this.

         ,-----------------------------------------> MAX_BLKADDR -,
         |  ,------------- TOTAL_BLKS ----------------------------,
         |  |                                                     |
         |  ,- seg0_blkaddr   ,----- sit/nat/ssa/main blkaddress  |
block    |  | (SEG0_BLKADDR)  | | | |   (e.g., MAIN_BLKADDR)      |
address  0..x................ a b c d .............................
            |                                                     |
global seg# 0...................... m .............................
            |                       |                             |
            |                       `------- MAIN_SEGS -----------'
            `-------------- TOTAL_SEGS ---------------------------'
                                    |                             |
 seg#                               0..........xx..................

= Note =
 o GET_SEGNO_FROM_SEG0 : blk address -> global segno
 o GET_SEGNO           : blk address -> segno
 o START_BLOCK         : segno -> starting block address
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch add a new data structure to control checkpoint parameters.
Currently, it presents the reason of checkpoint such as is_umount and normal
sync.
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In ->get_victim we get max_search value from dirty_i->nr_dirty without
protection of seglist_lock, after that, nr_dirty can be increased/decreased
before we hold seglist_lock lock.
Then in main loop we attempt to traverse all dirty section one time to find
victim section, but it's not accurate to use max_search as the total loop count,
because we might lose checking several sections or check sections redundantly
for the case of nr_dirty are increased or decreased previously.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Previously f2fs only counts dirty dentry pages, but there is no reason not to
expand the scope.

This patch changes the names on the management of dirty pages and to count
dirty pages in each inode info as well.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>