generic/232 reports below deadlock:

fsstress        D    0 96980  96969 0x00084000
Call Trace:
 schedule+0x4a/0xb0
 io_schedule+0x12/0x40
 __lock_page+0x127/0x1d0
 pagecache_get_page+0x1d8/0x250
 prepare_compress_overwrite+0xe0/0x490 [f2fs]
 f2fs_prepare_compress_overwrite+0x5d/0x80 [f2fs]
 f2fs_write_begin+0x833/0xb90 [f2fs]
 f2fs_quota_write+0x145/0x1e0 [f2fs]
 write_blk+0x36/0x80 [quota_tree]
 do_insert_tree+0x2ac/0x4a0 [quota_tree]
 do_insert_tree+0x26e/0x4a0 [quota_tree]
 qtree_write_dquot+0x70/0x190 [quota_tree]
 v2_write_dquot+0x43/0x90 [quota_v2]
 dquot_acquire+0x77/0x100
 f2fs_dquot_acquire+0x2f/0x60 [f2fs]
 dqget+0x310/0x450
 dquot_transfer+0xb2/0x120
 f2fs_setattr+0x11a/0x4a0 [f2fs]
 notify_change+0x349/0x480
 chown_common+0x168/0x1c0
 do_fchownat+0xbc/0xf0
 __x64_sys_lchown+0x21/0x30
 do_syscall_64+0x5f/0x220
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  task                        PC stack   pid father
kworker/u256:0  D    0 103444      2 0x80084000
Workqueue: writeback wb_workfn (flush-251:1)
Call Trace:
 schedule+0x4a/0xb0
 schedule_timeout+0x15e/0x2f0
 io_schedule_timeout+0x19/0x40
 congestion_wait+0x7e/0x120
 f2fs_write_multi_pages+0x12a/0x840 [f2fs]
 f2fs_write_cache_pages+0x48f/0x790 [f2fs]
 f2fs_write_data_pages+0x2db/0x330 [f2fs]
 do_writepages+0x1a/0x60
 __writeback_single_inode+0x3d/0x340
 writeback_sb_inodes+0x225/0x4a0
 wb_writeback+0xf7/0x320
 wb_workfn+0xba/0x470
 process_one_work+0x16c/0x3f0
 worker_thread+0x4c/0x440
 kthread+0xf8/0x130
 ret_from_fork+0x35/0x40

fsstress        D    0  5277   5266 0x00084000
Call Trace:
 schedule+0x4a/0xb0
 rwsem_down_write_slowpath+0x29d/0x540
 block_operations+0x105/0x360 [f2fs]
 f2fs_write_checkpoint+0x101/0x1010 [f2fs]
 f2fs_sync_fs+0xa8/0x130 [f2fs]
 f2fs_do_sync_file+0x1ad/0x890 [f2fs]
 do_fsync+0x38/0x60
 __x64_sys_fdatasync+0x13/0x20
 do_syscall_64+0x5f/0x220
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The root cause is there is potential deadlock between quota data
update and writeback.

Kworker					Thread B			Thread C
- f2fs_write_cache_pages
 - lock whole cluster	--- A
 - f2fs_write_multi_pages
  - f2fs_write_raw_pages
   - f2fs_write_single_data_page
    - f2fs_do_write_data_page
					- f2fs_setattr
					 - f2fs_lock_op	--- B
									- f2fs_write_checkpoint
									 - block_operations
									  - f2fs_lock_all --- B
					 - dquot_transfer
					  - f2fs_quota_write
					   - f2fs_prepare_compress_overwrite
					    - pagecache_get_page --- A
     - f2fs_trylock_op failed	--- B
  - congestion_wait
  - goto rewrite

To fix this issue, during quota file writeback, just redirty all pages
left in cluster rather holding pages' lock in cluster and looping retrying
lock cp_rwsem.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This lock can be a contention with multi 4k random read IO with single inode.

example) fio --output=test --name=test --numjobs=60 --filename=/media/samsung960pro/file_test --rw=randread --bs=4k
 --direct=1 --time_based --runtime=7 --ioengine=libaio --iodepth=256 --group_reporting --size=10G

With this commit, it remove that possible lock contention.
Signed-off-by: NDongjoo Seo <commisori28@gmail.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

- f2fs_iget
 - do_read_inode
  - set_inode_flag(, FI_COMPRESSED_FILE)
   - __mark_inode_dirty_flag(, true)

It's unnecessary, so let's just mark compressed inode dirty while
compressed inode conversion.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

por_fsstress reports inconsistent status in orphan inode, the root cause
of this is in f2fs_write_raw_pages() we decrease i_compr_blocks incorrectly
due to wrong calculation in f2fs_compressed_blocks().

So this patch exposes below two functions based on __f2fs_cluster_blocks:
- f2fs_compressed_blocks: get count of compressed blocks in compressed cluster
- f2fs_cluster_blocks: get count of valid blocks (including reserved blocks)
in compressed cluster.

Then use f2fs_compress_blocks() to get correct compressed blocks count in
f2fs_write_raw_pages().

sanity_check_inode: inode (ino=ad80) hash inconsistent i_compr_blocks:2, i_blocks:1, run fsck to fix
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

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
inadvertently 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 76497732 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Fields in struct f2fs_super_block should be updated under coverage
of sb_lock, fix to adjust update_sb_metadata() for that rule.

Fixes: 04f0b2ea ("f2fs: ioctl for removing a range from F2FS")
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Add and set a new CP flag CP_RESIZEFS_FLAG during
online resize FS to help fsck fix the metadata mismatch
that may happen due to SPO during resize, where SB
got updated but CP data couldn't be written yet.

fsck errors -
Info: CKPT version = 6ed7bccb
        Wrong user_block_count(2233856)
[f2fs_do_mount:3365] Checkpoint is polluted
Signed-off-by: NSahitya Tummala <stummala@codeaurora.org>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Even though online resize is successfully done, a SPO immediately
after resize, still causes below error in the next mount.

[   11.294650] F2FS-fs (sda8): Wrong user_block_count: 2233856
[   11.300272] F2FS-fs (sda8): Failed to get valid F2FS checkpoint

This is because after FS metadata is updated in update_fs_metadata()
if the SBI_IS_DIRTY is not dirty, then CP will not be done to reflect
the new user_block_count.
Signed-off-by: NSahitya Tummala <stummala@codeaurora.org>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

It's been observed that kzalloc() on lookup_all_xattrs() are called millions
of times on Android, quickly becoming the top abuser of slub memory allocator.

Use a dedicated kmem cache pool for xattr lookups to mitigate this.
Signed-off-by: NPark Ju Hyung <qkrwngud825@gmail.com>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

FG_GC needs to move entire section more quickly.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

__f2fs_bio_alloc() won't fail due to memory pool backend, remove unneeded
__GFP_NOFAIL flag in __f2fs_bio_alloc().
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

With this newly introduced interface, user can get block
number compression saved in target inode.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If we are in write IO path, we need to avoid using GFP_KERNEL.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In order to avoid polluting global slab cache namespace.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

As Geert Uytterhoeven reported:

for parameter HZ/50 in congestion_wait(BLK_RW_ASYNC, HZ/50);

On some platforms, HZ can be less than 50, then unexpected 0 timeout
jiffies will be set in congestion_wait().

This patch introduces a macro DEFAULT_IO_TIMEOUT to wrap a determinate
value with msecs_to_jiffies(20) to instead HZ/50 to avoid such issue.

Quoted from Geert Uytterhoeven:

"A timeout of HZ means 1 second.
HZ/50 means 20 ms, but has the risk of being zero, if HZ < 50.

If you want to use a timeout of 20 ms, you best use msecs_to_jiffies(20),
as that takes care of the special cases, and never returns 0."
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This fixes skipping GC when segment is full in large section.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If first segment is empty and migration_granularity is 1, we can't move this
at all.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

There are three status for background gc: on, off and sync, it's
a little bit confused to use test_opt(BG_GC) and test_opt(FORCE_FG_GC)
combinations to indicate status of background gc.

So let's remove F2FS_MOUNT_BG_GC and F2FS_MOUNT_FORCE_FG_GC mount
options, and add F2FS_OPTION().bggc_mode with below three status
to clean up codes and enhance bggc mode's scalability.

enum {
	BGGC_MODE_ON,		/* background gc is on */
	BGGC_MODE_OFF,		/* background gc is off */
	BGGC_MODE_SYNC,		/*
				 * background gc is on, migrating blocks
				 * like foreground gc
				 */
};
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch removes F2FS_MOUNT_ADAPTIVE and F2FS_MOUNT_LFS mount options,
and add F2FS_OPTION.fs_mode with below two status to indicate filesystem
mode.

enum {
	FS_MODE_ADAPTIVE,	/* use both lfs/ssr allocation */
	FS_MODE_LFS,		/* use lfs allocation only */
};

It can enhance code readability and fs mode's scalability.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Previously, 'norecovery' mount option will be shown as
'disable_roll_forward', fix to show original option name correctly.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Just cleanup, no logic change.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

- rename datablock_addr() to data_blkaddr().
- wrap data_blkaddr() with f2fs_data_blkaddr() to clean up
parameters.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Let's show mounted time.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@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().
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If regular inode has no compressed cluster, allow using 'chattr -c'
to remove its compress flag, recovering it to a non-compressed file.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Compressed cluster can be generated during dirty data writeback,
if there is dirty pages on compressed inode, it needs to disable
converting compressed inode to non-compressed one.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

stat_inc_compr_inode() needs to check FI_COMPRESSED_FILE flag, so
in f2fs_disable_compressed_file(), we should call stat_dec_compr_inode()
before clearing FI_COMPRESSED_FILE flag.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This fixes the incorrect failure when enabling project quota on casefold-enabled
file.

Cc: Daniel Rosenberg <drosen@google.com>
Cc: kernel-team@android.com
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In compress cluster, if physical block number is less than logic
page number, race condition will cause use-after-free issue as
described below:

- f2fs_write_compressed_pages
 - fio.page = cic->rpages[0];
 - f2fs_outplace_write_data
					- f2fs_compress_write_end_io
					 - kfree(cic->rpages);
					 - kfree(cic);
 - fio.page = cic->rpages[1];

f2fs_write_multi_pages+0xfd0/0x1a98
f2fs_write_data_pages+0x74c/0xb5c
do_writepages+0x64/0x108
__writeback_single_inode+0xdc/0x4b8
writeback_sb_inodes+0x4d0/0xa68
__writeback_inodes_wb+0x88/0x178
wb_writeback+0x1f0/0x424
wb_workfn+0x2f4/0x574
process_one_work+0x210/0x48c
worker_thread+0x2e8/0x44c
kthread+0x110/0x120
ret_from_fork+0x10/0x18

Fixes: 4c8ff709 ("f2fs: support data compression")
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In f2fs_vm_page_mkwrite(), if inode is compress one, and current mmapped
page locates in compressed cluster, we have to call f2fs_get_dnode_of_data()
to get its physical block address before f2fs_wait_on_block_writeback().
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Lack of maintenance on comments may mislead developers, fix them.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

f2fs_inode.xattr_ver field was gone after commit d260081c
("f2fs: change recovery policy of xattr node block"), remove i_sem
lock coverage in f2fs_setxattr()
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This change solves below hangtask issue:

INFO: task kworker/u16:1:58 blocked for more than 122 seconds.
      Not tainted 5.6.0-rc2-00590-g9983bdae4974e #11
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/u16:1   D    0    58      2 0x00000000
Workqueue: writeback wb_workfn (flush-179:0)
Backtrace:
 (__schedule) from [<c0913234>] (schedule+0x78/0xf4)
 (schedule) from [<c017ec74>] (rwsem_down_write_slowpath+0x24c/0x4c0)
 (rwsem_down_write_slowpath) from [<c0915f2c>] (down_write+0x6c/0x70)
 (down_write) from [<c0435b80>] (f2fs_write_single_data_page+0x608/0x7ac)
 (f2fs_write_single_data_page) from [<c0435fd8>] (f2fs_write_cache_pages+0x2b4/0x7c4)
 (f2fs_write_cache_pages) from [<c043682c>] (f2fs_write_data_pages+0x344/0x35c)
 (f2fs_write_data_pages) from [<c0267ee8>] (do_writepages+0x3c/0xd4)
 (do_writepages) from [<c0310cbc>] (__writeback_single_inode+0x44/0x454)
 (__writeback_single_inode) from [<c03112d0>] (writeback_sb_inodes+0x204/0x4b0)
 (writeback_sb_inodes) from [<c03115cc>] (__writeback_inodes_wb+0x50/0xe4)
 (__writeback_inodes_wb) from [<c03118f4>] (wb_writeback+0x294/0x338)
 (wb_writeback) from [<c0312dac>] (wb_workfn+0x35c/0x54c)
 (wb_workfn) from [<c014f2b8>] (process_one_work+0x214/0x544)
 (process_one_work) from [<c014f634>] (worker_thread+0x4c/0x574)
 (worker_thread) from [<c01564fc>] (kthread+0x144/0x170)
 (kthread) from [<c01010e8>] (ret_from_fork+0x14/0x2c)
Reported-and-tested-by: NOndřej Jirman <megi@xff.cz>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

inode.i_blocks counts based on 512byte sector, we need to convert
to 4kb sized block count before comparing to i_compr_blocks.

In addition, add to print message when sanity check on inode
compression configs failed.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Using f2fs_trylock_op() in f2fs_write_compressed_pages() to avoid potential
deadlock like we did in f2fs_write_single_data_page().
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Otherwise, we can not distinguish the exact location of messages,
when there are more than one places printing same message.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In Struct compress_data, chksum field was never used, remove it.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Unable to handle kernel NULL pointer dereference at virtual address 00000000
PC is at f2fs_free_dic+0x60/0x2c8
LR is at f2fs_decompress_pages+0x3c4/0x3e8
f2fs_free_dic+0x60/0x2c8
f2fs_decompress_pages+0x3c4/0x3e8
__read_end_io+0x78/0x19c
f2fs_post_read_work+0x6c/0x94
process_one_work+0x210/0x48c
worker_thread+0x2e8/0x44c
kthread+0x110/0x120
ret_from_fork+0x10/0x18

In f2fs_free_dic(), we can not use f2fs_put_page(,1) to release dic->tpages[i],
as the page's mapping is NULL.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

When the compressed data of a cluster doesn't end on a page boundary,
the remainder of the last page must be zeroed in order to avoid leaking
uninitialized memory to disk.

Fixes: 4c8ff709 ("f2fs: support data compression")
Signed-off-by: NEric Biggers <ebiggers@google.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>