Let's guarantee flusing dirty meta pages to avoid infinite loop.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Sahitya raised an issue:
- prevent meta updates while checkpoint is in progress

allocate_segment_for_resize() can cause metapage updates if
it requires to change the current node/data segments for resizing.
Stop these meta updates when there is a checkpoint already
in progress to prevent inconsistent CP data.
Signed-off-by: NSahitya Tummala <stummala@codeaurora.org>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

There could be a scenario where f2fs_sync_node_pages gets
called during checkpoint, which in turn tries to flush
inline data and calls iput(). This results in deadlock as
iput() tries to hold cp_rwsem, which is already held at the
beginning by checkpoint->block_operations().

Call stack :

Thread A		Thread B
f2fs_write_checkpoint()
- block_operations(sbi)
 - f2fs_lock_all(sbi);
  - down_write(&sbi->cp_rwsem);

                        - open()
                         - igrab()
                        - write() write inline data
                        - unlink()
- f2fs_sync_node_pages()
 - if (is_inline_node(page))
  - flush_inline_data()
   - ilookup()
     page = f2fs_pagecache_get_page()
     if (!page)
      goto iput_out;
     iput_out:
			-close()
			-iput()
       iput(inode);
       - f2fs_evict_inode()
        - f2fs_truncate_blocks()
         - f2fs_lock_op()
           - down_read(&sbi->cp_rwsem);

Fixes: 2049d4fc ("f2fs: avoid multiple node page writes due to inline_data")
Signed-off-by: NSayali Lokhande <sayalil@codeaurora.org>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

blk_plugging doesn't seem to give any benefit.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Adds to support accounting read IOs from userspace/kernel.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In f2fs_ra_meta_pages(), if f2fs_submit_page_bio() failed, we need to
unlock page, fix it.
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>

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>

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>

There could be a scenario where f2fs_sync_meta_pages() will not
ensure that all F2FS_DIRTY_META pages are submitted for IO. Thus,
resulting in the below panic in do_checkpoint() -

f2fs_bug_on(sbi, get_pages(sbi, F2FS_DIRTY_META) &&
				!f2fs_cp_error(sbi));

This can happen in a low-memory condition, where shrinker could
also be doing the writepage operation (stack shown below)
at the same time when checkpoint is running on another core.

schedule
down_write
f2fs_submit_page_write -> by this time, this page in page cache is tagged
			as PAGECACHE_TAG_WRITEBACK and PAGECACHE_TAG_DIRTY
			is cleared, due to which f2fs_sync_meta_pages()
			cannot sync this page in do_checkpoint() path.
f2fs_do_write_meta_page
__f2fs_write_meta_page
f2fs_write_meta_page
shrink_page_list
shrink_inactive_list
shrink_node_memcg
shrink_node
kswapd
Signed-off-by: NSahitya Tummala <stummala@codeaurora.org>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

META_MAPPING is used to move blocks for both encrypted and verity files.
So the META_MAPPING invalidation condition in do_checkpoint() should
consider verity too, not just encrypt.
Signed-off-by: NEric Biggers <ebiggers@google.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

As Eric mentioned, bare printk{,_ratelimited} won't show which
filesystem instance these message is coming from, this patch tries
to show fs instance with sb->s_id field in all places we missed
before.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Two paths to update quota and f2fs_lock_op:

1.
 - lock_op
 |  - quota_update
 `- unlock_op

2.
 - quota_update
 - lock_op
 `- unlock_op

But, we need to make a transaction on quota_update + lock_op in #2 case.
So, this patch introduces:
1. lock_op
2. down_write
3. check __need_flush
4. up_write
5. if there is dirty quota entries, flush them
6. otherwise, good to go
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

f2fs uses EFAULT as error number to indicate filesystem is corrupted
all the time, but generic filesystems use EUCLEAN for such condition,
we need to change to follow others.

This patch adds two new macros as below to wrap more generic error
code macros, and spread them in code.

EFSBADCRC	EBADMSG		/* Bad CRC detected */
EFSCORRUPTED	EUCLEAN		/* Filesystem is corrupted */
Reported-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

- Add and use f2fs_<level> macros
- Convert f2fs_msg to f2fs_printk
- Remove level from f2fs_printk and embed the level in the format
- Coalesce formats and align multi-line arguments
- Remove unnecessary duplicate extern f2fs_msg f2fs.h
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This ioctl shrinks a given length (aligned to sections) from end of the
main area. Any cursegs and valid blocks will be moved out before
invalidating the range.

This feature can be used for adjusting partition sizes online.

History of the patch:

Sahitya Tummala:
 - Add this ioctl for f2fs_compat_ioctl() as well.
 - Fix debugfs status to reflect the online resize changes.
 - Fix potential race between online resize path and allocate new data
   block path or gc path.

Others:
 - Rename some identifiers.
 - Add some error handling branches.
 - Clear sbi->next_victim_seg[BG_GC/FG_GC] in shrinking range.
 - Implement this interface as ext4's, and change the parameter from shrunk
bytes to new block count of F2FS.
 - During resizing, force to empty sit_journal and forbid adding new
   entries to it, in order to avoid invalid segno in journal after resize.
 - Reduce sbi->user_block_count before resize starts.
 - Commit the updated superblock first, and then update in-memory metadata
   only when the former succeeds.
 - Target block count must align to sections.
 - Write checkpoint before and after committing the new superblock, w/o
CP_FSCK_FLAG respectively, so that the FS can be fixed by fsck even if
resize fails after the new superblock is committed.
 - In free_segment_range(), reduce granularity of gc_mutex.
 - Add protection on curseg migration.
 - Add freeze_bdev() and thaw_bdev() for resize fs.
 - Remove CUR_MAIN_SECS and use MAIN_SECS directly for allocation.
 - Recover super_block and FS metadata when resize fails.
 - No need to clear CP_FSCK_FLAG in update_ckpt_flags().
 - Clean up the sb and fs metadata update functions for resize_fs.

Geert Uytterhoeven:
 - Use div_u64*() for 64-bit divisions

Arnd Bergmann:
 - Not all architectures support get_user() with a 64-bit argument:
    ERROR: "__get_user_bad" [fs/f2fs/f2fs.ko] undefined!
    Use copy_from_user() here, this will always work.
Signed-off-by: NQiuyang Sun <sunqiuyang@huawei.com>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NSahitya Tummala <stummala@codeaurora.org>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

As Ju Hyung reported:

"
I was semi-forced today to use the new kernel and test f2fs.

My Ubuntu initramfs got a bit wonky and I had to boot into live CD and
fix some stuffs. The live CD was using 4.15 kernel, and just mounting
the f2fs partition there corrupted f2fs and my 4.19(with 5.1-rc1-4.19
f2fs-stable merged) refused to mount with "SIT is corrupted node"
message.

I used the latest f2fs-tools sent by Chao including "fsck.f2fs: fix to
repair cp_loads blocks at correct position"

It spit out 140M worth of output, but at least I didn't have to run it
twice. Everything returned "Ok" in the 2nd run.
The new log is at
http://arter97.com/f2fs/final

After fixing the image, I used my 4.19 kernel with 5.2-rc1-4.19
f2fs-stable merged and it mounted.

But, I got this:
[    1.047791] F2FS-fs (nvme0n1p3): layout of large_nat_bitmap is
deprecated, run fsck to repair, chksum_offset: 4092
[    1.081307] F2FS-fs (nvme0n1p3): Found nat_bits in checkpoint
[    1.161520] F2FS-fs (nvme0n1p3): recover fsync data on readonly fs
[    1.162418] F2FS-fs (nvme0n1p3): Mounted with checkpoint version = 761c7e00

But after doing a reboot, the message is gone:
[    1.098423] F2FS-fs (nvme0n1p3): Found nat_bits in checkpoint
[    1.177771] F2FS-fs (nvme0n1p3): recover fsync data on readonly fs
[    1.178365] F2FS-fs (nvme0n1p3): Mounted with checkpoint version = 761c7eda

I'm not exactly sure why the kernel detected that I'm still using the
old layout on the first boot. Maybe fsck didn't fix it properly, or
the check from the kernel is improper.
"

Although we have rebuild the old deprecated checkpoint with new layout
during repair, we only repair last checkpoint park, the other old one is
remained.

Once the image was mounted, we will 1) sanity check layout and 2) decide
which checkpoint park to use according to cp_ver. So that we will print
reported message unnecessarily at step 1), to avoid it, we simply move
layout check into f2fs_sanity_check_ckpt() after step 2).
Reported-by: NPark Ju Hyung <qkrwngud825@gmail.com>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch reverts:
commit fb40d618 ("f2fs: don't clear CP_QUOTA_NEED_FSCK_FLAG").

We were missing error handlers used in f2fs quota ops.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Use sbi.stat_lock to protect sbi->unusable_block_count accesss/udpate, in
order to avoid potential race on it.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Previously, f2fs_is_valid_blkaddr(, blkaddr, DATA_GENERIC) will check
whether @blkaddr locates in main area or not.

That check is weak, since the block address in range of main area can
point to the address which is not valid in segment info table, and we
can not detect such condition, we may suffer worse corruption as system
continues running.

So this patch introduce DATA_GENERIC_ENHANCE to enhance the sanity check
which trigger SIT bitmap check rather than only range check.

This patch did below changes as wel:
- set SBI_NEED_FSCK in f2fs_is_valid_blkaddr().
- get rid of is_valid_data_blkaddr() to avoid panic if blkaddr is invalid.
- introduce verify_fio_blkaddr() to wrap fio {new,old}_blkaddr validation check.
- spread blkaddr check in:
 * f2fs_get_node_info()
 * __read_out_blkaddrs()
 * f2fs_submit_page_read()
 * ra_data_block()
 * do_recover_data()

This patch can fix bug reported from bugzilla below:

https://bugzilla.kernel.org/show_bug.cgi?id=203215
https://bugzilla.kernel.org/show_bug.cgi?id=203223
https://bugzilla.kernel.org/show_bug.cgi?id=203231
https://bugzilla.kernel.org/show_bug.cgi?id=203235
https://bugzilla.kernel.org/show_bug.cgi?id=203241

= Update by Jaegeuk Kim =

DATA_GENERIC_ENHANCE enhanced to validate block addresses on read/write paths.
But, xfstest/generic/446 compalins some generated kernel messages saying invalid
bitmap was detected when reading a block. The reaons is, when we get the
block addresses from extent_cache, there is no lock to synchronize it from
truncating the blocks in parallel.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

As Park Ju Hyung reported:

Probably unrelated but a similar issue:
Warning appears upon unmounting a corrupted R/O f2fs loop image.

Should be a trivial issue to fix as well :)

[ 2373.758424] ------------[ cut here ]------------
[ 2373.758428] generic_make_request: Trying to write to read-only
block-device loop1 (partno 0)
[ 2373.758455] WARNING: CPU: 1 PID: 13950 at block/blk-core.c:2174
generic_make_request_checks+0x590/0x630
[ 2373.758556] CPU: 1 PID: 13950 Comm: umount Tainted: G           O
   4.19.35-zen+ #1
[ 2373.758558] Hardware name: System manufacturer System Product
Name/ROG MAXIMUS X HERO (WI-FI AC), BIOS 1704 09/14/2018
[ 2373.758564] RIP: 0010:generic_make_request_checks+0x590/0x630
[ 2373.758567] Code: 5c 03 00 00 48 8d 74 24 08 48 89 df c6 05 b5 cd
36 01 01 e8 c2 90 01 00 48 89 c6 44 89 ea 48 c7 c7 98 64 59 82 e8 d5
9b a7 ff <0f> 0b 48 8b 7b 08 e9 f2 fa ff ff 41 8b 86 98 02 00 00 49 8b
16 89
[ 2373.758570] RSP: 0018:ffff8882bdb43950 EFLAGS: 00010282
[ 2373.758573] RAX: 0000000000000050 RBX: ffff8887244c6700 RCX: 0000000000000006
[ 2373.758575] RDX: 0000000000000007 RSI: 0000000000000086 RDI: ffff88884ec56340
[ 2373.758577] RBP: ffff888849c426c0 R08: 0000000000000004 R09: 00000000000003ba
[ 2373.758579] R10: 0000000000000001 R11: 0000000000000029 R12: 0000000000001000
[ 2373.758581] R13: 0000000000000000 R14: ffff888844a2e800 R15: ffff8882bdb43ac0
[ 2373.758584] FS:  00007fc0d114f8c0(0000) GS:ffff88884ec40000(0000)
knlGS:0000000000000000
[ 2373.758586] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 2373.758588] CR2: 00007fc0d1ad12c0 CR3: 00000002bdb82003 CR4: 00000000003606e0
[ 2373.758590] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 2373.758592] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 2373.758593] Call Trace:
[ 2373.758602]  ? generic_make_request+0x46/0x3d0
[ 2373.758608]  ? wait_woken+0x80/0x80
[ 2373.758612]  ? mempool_alloc+0xb7/0x1a0
[ 2373.758618]  ? submit_bio+0x30/0x110
[ 2373.758622]  ? bvec_alloc+0x7c/0xd0
[ 2373.758628]  ? __submit_merged_bio+0x68/0x390
[ 2373.758633]  ? f2fs_submit_page_write+0x1bb/0x7f0
[ 2373.758638]  ? f2fs_do_write_meta_page+0x7f/0x160
[ 2373.758642]  ? __f2fs_write_meta_page+0x70/0x140
[ 2373.758647]  ? f2fs_sync_meta_pages+0x140/0x250
[ 2373.758653]  ? f2fs_write_checkpoint+0x5c5/0x17b0
[ 2373.758657]  ? f2fs_sync_fs+0x9c/0x110
[ 2373.758664]  ? sync_filesystem+0x66/0x80
[ 2373.758667]  ? generic_shutdown_super+0x1d/0x100
[ 2373.758670]  ? kill_block_super+0x1c/0x40
[ 2373.758674]  ? kill_f2fs_super+0x64/0xb0
[ 2373.758678]  ? deactivate_locked_super+0x2d/0xb0
[ 2373.758682]  ? cleanup_mnt+0x65/0xa0
[ 2373.758688]  ? task_work_run+0x7f/0xa0
[ 2373.758693]  ? exit_to_usermode_loop+0x9c/0xa0
[ 2373.758698]  ? do_syscall_64+0xc7/0xf0
[ 2373.758703]  ? entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 2373.758706] ---[ end trace 5d3639907c56271b ]---
[ 2373.758780] print_req_error: I/O error, dev loop1, sector 143048
[ 2373.758800] print_req_error: I/O error, dev loop1, sector 152200
[ 2373.758808] print_req_error: I/O error, dev loop1, sector 8192
[ 2373.758819] print_req_error: I/O error, dev loop1, sector 12272

This patch adds to detect readonly device in write_checkpoint() to avoid
trigger write IOs on it.
Reported-by: NPark Ju Hyung <qkrwngud825@gmail.com>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

As Park Ju Hyung reported in mailing list:

https://sourceforge.net/p/linux-f2fs/mailman/message/36639787/

generic_make_request: Trying to write to read-only block-device loop0 (partno 0)
WARNING: CPU: 0 PID: 23437 at block/blk-core.c:2174 generic_make_request_checks+0x594/0x630

 generic_make_request+0x46/0x3d0
 submit_bio+0x30/0x110
 __submit_merged_bio+0x68/0x390
 f2fs_submit_page_write+0x1bb/0x7f0
 f2fs_do_write_meta_page+0x7f/0x160
 __f2fs_write_meta_page+0x70/0x140
 f2fs_sync_meta_pages+0x140/0x250
 f2fs_write_checkpoint+0x5c5/0x17b0
 f2fs_sync_fs+0x9c/0x110
 sync_filesystem+0x66/0x80
 f2fs_recover_fsync_data+0x790/0xa30
 f2fs_fill_super+0xe4e/0x1980
 mount_bdev+0x518/0x610
 mount_fs+0x34/0x13f
 vfs_kern_mount.part.11+0x4f/0x120
 do_mount+0x2d1/0xe40
 __x64_sys_mount+0xbf/0xe0
 do_syscall_64+0x4a/0xf0
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

print_req_error: I/O error, dev loop0, sector 4096

If block device is readonly, we should never trigger write IO from
filesystem layer, but previously, orphan and journal recovery didn't
consider such condition, result in triggering above warning, fix it.
Reported-by: NPark Ju Hyung <qkrwngud825@gmail.com>
Tested-by: NPark Ju Hyung <qkrwngud825@gmail.com>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

For large_nat_bitmap feature, there is a design flaw:

Previous:

struct f2fs_checkpoint layout:
+--------------------------+  0x0000
| checkpoint_ver           |
| ......                   |
| checksum_offset          |------+
| ......                   |      |
| sit_nat_version_bitmap[] |<-----|-------+
| ......                   |      |       |
| checksum_value           |<-----+       |
+--------------------------+  0x1000      |
|                          |      nat_bitmap + sit_bitmap
| payload blocks           |              |
|                          |              |
+--------------------------|<-------------+

Obviously, if nat_bitmap size + sit_bitmap size is larger than
MAX_BITMAP_SIZE_IN_CKPT, nat_bitmap or sit_bitmap may overlap
checkpoint checksum's position, once checkpoint() is triggered
from kernel, nat or sit bitmap will be damaged by checksum field.

In order to fix this, let's relocate checksum_value's position
to the head of sit_nat_version_bitmap as below, then nat/sit
bitmap and chksum value update will become safe.

After:

struct f2fs_checkpoint layout:
+--------------------------+  0x0000
| checkpoint_ver           |
| ......                   |
| checksum_offset          |------+
| ......                   |      |
| sit_nat_version_bitmap[] |<-----+
| ......                   |<-------------+
|                          |              |
+--------------------------+  0x1000      |
|                          |      nat_bitmap + sit_bitmap
| payload blocks           |              |
|                          |              |
+--------------------------|<-------------+

Related report and discussion:

https://sourceforge.net/p/linux-f2fs/mailman/message/36642346/Reported-by: NPark Ju Hyung <qkrwngud825@gmail.com>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Previously, f2fs_checkpoint.checksum_offset points fixed position of
f2fs_checkpoint structure:

"#define CP_CHKSUM_OFFSET	4092"

It is unnecessary, and it breaks the consecutiveness of nat and sit
bitmap stored across checkpoint park block and payload blocks.

This patch allows f2fs to handle unfixed .checksum_offset.

In addition, for the case checksum value is stored in the middle of
checkpoint park, calculating checksum value with superposition method
like we did for inode_checksum.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch changes codes as below:
- don't use is_read_io() as a condition to judge the meta IO.
- use .is_por to replace .is_meta to indicate IO is from recovery explicitly.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

As Hagbard Celine reported:

Hi, this is a long standing bug that I've hit before on older kernels,
but I was not able to get the syslog saved because of the nature of
the bug. This time I had booted form a pen-drive, and was able to save
the log to it's efi-partition.
What i did to trigger it was to create a partition and format it f2fs,
then mount it with options:
"rw,relatime,lazytime,background_gc=on,disable_ext_identify,discard,heap,user_xattr,inline_xattr,acl,inline_data,inline_dentry,flush_merge,data_flush,extent_cache,mode=adaptive,active_logs=6,whint_mode=fs-based,alloc_mode=default,fsync_mode=strict".
Then I unpacked a big .tar.xz to the partition (I used a
gentoo-stage3-tarball as I was in process of installing Gentoo).

Same options just without data_flush gives no problems.

Mar 20 20:54:01 usbgentoo kernel: FAT-fs (nvme0n1p4): Volume was not
properly unmounted. Some data may be corrupt. Please run fsck.
Mar 20 21:05:23 usbgentoo kernel: kworker/dying (1588) used greatest
stack depth: 12064 bytes left
Mar 20 21:06:40 usbgentoo kernel: BUG: stack guard page was hit at
00000000a4b0733c (stack is 0000000056016422..0000000096e7463f)
Mar 20 21:06:40 usbgentoo kernel: kernel stack overflow

......

Mar 20 21:06:40 usbgentoo kernel: Call Trace:
Mar 20 21:06:40 usbgentoo kernel:  read_node_page+0x71/0xf0
Mar 20 21:06:40 usbgentoo kernel:  ? xas_load+0x8/0x50
Mar 20 21:06:40 usbgentoo kernel:  __get_node_page+0x73/0x2a0
Mar 20 21:06:40 usbgentoo kernel:  f2fs_get_dnode_of_data+0x34e/0x580
Mar 20 21:06:40 usbgentoo kernel:  f2fs_write_inline_data+0x5e/0x2a0
Mar 20 21:06:40 usbgentoo kernel:  __write_data_page+0x421/0x690
Mar 20 21:06:40 usbgentoo kernel:  f2fs_write_cache_pages+0x1cf/0x460
Mar 20 21:06:40 usbgentoo kernel:  f2fs_write_data_pages+0x2b3/0x2e0
Mar 20 21:06:40 usbgentoo kernel:  ? f2fs_inode_chksum_verify+0x1d/0xc0
Mar 20 21:06:40 usbgentoo kernel:  ? read_node_page+0x71/0xf0
Mar 20 21:06:40 usbgentoo kernel:  do_writepages+0x3c/0xd0
Mar 20 21:06:40 usbgentoo kernel:  __filemap_fdatawrite_range+0x7c/0xb0
Mar 20 21:06:40 usbgentoo kernel:  f2fs_sync_dirty_inodes+0xf2/0x200
Mar 20 21:06:40 usbgentoo kernel:  f2fs_balance_fs_bg+0x2a3/0x2c0
Mar 20 21:06:40 usbgentoo kernel:  ? f2fs_inode_dirtied+0x21/0xc0
Mar 20 21:06:40 usbgentoo kernel:  f2fs_balance_fs+0xd6/0x2b0
Mar 20 21:06:40 usbgentoo kernel:  __write_data_page+0x4fb/0x690

......

Mar 20 21:06:40 usbgentoo kernel:  __writeback_single_inode+0x2a1/0x340
Mar 20 21:06:40 usbgentoo kernel:  ? soft_cursor+0x1b4/0x220
Mar 20 21:06:40 usbgentoo kernel:  writeback_sb_inodes+0x1d5/0x3e0
Mar 20 21:06:40 usbgentoo kernel:  __writeback_inodes_wb+0x58/0xa0
Mar 20 21:06:40 usbgentoo kernel:  wb_writeback+0x250/0x2e0
Mar 20 21:06:40 usbgentoo kernel:  ? 0xffffffff8c000000
Mar 20 21:06:40 usbgentoo kernel:  ? cpumask_next+0x16/0x20
Mar 20 21:06:40 usbgentoo kernel:  wb_workfn+0x2f6/0x3b0
Mar 20 21:06:40 usbgentoo kernel:  ? __switch_to_asm+0x40/0x70
Mar 20 21:06:40 usbgentoo kernel:  process_one_work+0x1f5/0x3f0
Mar 20 21:06:40 usbgentoo kernel:  worker_thread+0x28/0x3c0
Mar 20 21:06:40 usbgentoo kernel:  ? rescuer_thread+0x330/0x330
Mar 20 21:06:40 usbgentoo kernel:  kthread+0x10e/0x130
Mar 20 21:06:40 usbgentoo kernel:  ? kthread_create_on_node+0x60/0x60
Mar 20 21:06:40 usbgentoo kernel:  ret_from_fork+0x35/0x40

The root cause is that we run into an infinite recursive calling in
between f2fs_balance_fs_bg and writepage() as described below:

- f2fs_write_data_pages		--- A
 - __write_data_page
  - f2fs_balance_fs
   - f2fs_balance_fs_bg		--- B
    - f2fs_sync_dirty_inodes
     - filemap_fdatawrite
      - f2fs_write_data_pages	--- A
...
          - f2fs_balance_fs_bg	--- B
...

In order to fix this issue, let's detect such condition in __write_data_page()
and just skip calling f2fs_balance_fs() recursively.
Reported-by: NHagbard Celine <hagbardcelin@gmail.com>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

As Gao Xiang reported in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=202749

f2fs may skip pageout() due to incorrect page reference count.

The problem here is that MM defined the rule [1] very clearly that
once page was set with PG_private flag, we should increment the
refcount in that page, also main flows like pageout(), migrate_page()
will assume there is one additional page reference count if
page_has_private() returns true.

But currently, f2fs won't add/del refcount when changing PG_private
flag. Anyway, f2fs should follow MM's rule to make MM's related flows
running as expected.

[1] https://lore.kernel.org/lkml/2b19b3c4-2bc4-15fa-15cc-27a13e5c7af1@aol.com/Reported-by: NGao Xiang <gaoxiang25@huawei.com>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If we met this once, let fsck.f2fs clear this only.
Note that, this addresses all the subtle fault injection test.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Some works after roll-forward recovery can get an error which will release
all the data structures. Let's flush them in order to make it clean.

One possible corruption came from:

[   90.400500] list_del corruption. prev->next should be ffffffed1f566208, but was (null)
[   90.675349] Call trace:
[   90.677869]  __list_del_entry_valid+0x94/0xb4
[   90.682351]  remove_dirty_inode+0xac/0x114
[   90.686563]  __f2fs_write_data_pages+0x6a8/0x6c8
[   90.691302]  f2fs_write_data_pages+0x40/0x4c
[   90.695695]  do_writepages+0x80/0xf0
[   90.699372]  __writeback_single_inode+0xdc/0x4ac
[   90.704113]  writeback_sb_inodes+0x280/0x440
[   90.708501]  wb_writeback+0x1b8/0x3d0
[   90.712267]  wb_workfn+0x1a8/0x4d4
[   90.715765]  process_one_work+0x1c0/0x3d4
[   90.719883]  worker_thread+0x224/0x344
[   90.723739]  kthread+0x120/0x130
[   90.727055]  ret_from_fork+0x10/0x18
Reported-by: NSahitya Tummala <stummala@codeaurora.org>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This mode returns mount() quickly with EAGAIN. We can trigger this by
shutdown(F2FS_GOING_DOWN_NEED_FSCK).
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

For all ordered cases in f2fs_wait_on_page_writeback(), we need to
check PageWriteback status, so let's clean up to relocate the check
into f2fs_wait_on_page_writeback().
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch cleans up checkpoint flow a bit:
- remove unneeded circulation of flushing meta pages.
- don't flush nat_bits pages in prior to other checkpoint pages.
- add bug_on to check remained meta pages after flushing.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

One report says memalloc failure during mount.

 (unwind_backtrace) from [<c010cd4c>] (show_stack+0x10/0x14)
 (show_stack) from [<c049c6b8>] (dump_stack+0x8c/0xa0)
 (dump_stack) from [<c024fcf0>] (warn_alloc+0xc4/0x160)
 (warn_alloc) from [<c0250218>] (__alloc_pages_nodemask+0x3f4/0x10d0)
 (__alloc_pages_nodemask) from [<c0270450>] (kmalloc_order_trace+0x2c/0x120)
 (kmalloc_order_trace) from [<c03fa748>] (build_node_manager+0x35c/0x688)
 (build_node_manager) from [<c03de494>] (f2fs_fill_super+0xf0c/0x16cc)
 (f2fs_fill_super) from [<c02a5864>] (mount_bdev+0x15c/0x188)
 (mount_bdev) from [<c03da624>] (f2fs_mount+0x18/0x20)
 (f2fs_mount) from [<c02a68b8>] (mount_fs+0x158/0x19c)
 (mount_fs) from [<c02c3c9c>] (vfs_kern_mount+0x78/0x134)
 (vfs_kern_mount) from [<c02c76ac>] (do_mount+0x474/0xca4)
 (do_mount) from [<c02c8264>] (SyS_mount+0x94/0xbc)
 (SyS_mount) from [<c0108180>] (ret_fast_syscall+0x0/0x48)
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch reorders flow from

- update page
- set_page_dirty
- wait_on_page_writeback

to

- wait_on_page_writeback
- update page
- set_page_dirty

The reason is:
- set_page_dirty will increase reference of dirty page, the reference
should be cleared before wait_on_page_writeback to keep its consistency.
- some devices need stable page during page writebacking, so we
should not change page's data.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In F2FS_HAS_FEATURE(), we will use F2FS_SB(sb) to get sbi pointer to
access .raw_super field, to avoid unneeded pointer conversion, this
patch changes to F2FS_HAS_FEATURE() accept sbi parameter directly.

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

For journalled quota mode, let checkpoint to flush dquot dirty data
and quota file data to guarntee persistence of all quota sysfile in
last checkpoint, by this way, we can avoid corrupting quota sysfile
when encountering SPO.

The implementation is as below:

1. add a global state SBI_QUOTA_NEED_FLUSH to indicate that there is
cached dquot metadata changes in quota subsystem, and later checkpoint
should:
 a) flush dquot metadata into quota file.
 b) flush quota file to storage to keep file usage be consistent.

2. add a global state SBI_QUOTA_NEED_REPAIR to indicate that quota
operation failed due to -EIO or -ENOSPC, so later,
 a) checkpoint will skip syncing dquot metadata.
 b) CP_QUOTA_NEED_FSCK_FLAG will be set in last cp pack to give a
    hint for fsck repairing.

3. add a global state SBI_QUOTA_SKIP_FLUSH, in checkpoint, if quota
data updating is very heavy, it may cause hungtask in block_operation().
To avoid this, if our retry time exceed threshold, let's just skip
flushing and retry in next checkpoint().
Signed-off-by: NWeichao Guo <guoweichao@huawei.com>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
[Jaegeuk Kim: avoid warnings and set fsck flag]
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Note that, it requires "f2fs: return correct errno in f2fs_gc".

This adds a lightweight non-persistent snapshotting scheme to f2fs.

To use, mount with the option checkpoint=disable, and to return to
normal operation, remount with checkpoint=enable. If the filesystem
is shut down before remounting with checkpoint=enable, it will revert
back to its apparent state when it was first mounted with
checkpoint=disable. This is useful for situations where you wish to be
able to roll back the state of the disk in case of some critical
failure.
Signed-off-by: NDaniel Rosenberg <drosen@google.com>
[Jaegeuk Kim: use SB_RDONLY instead of MS_RDONLY]
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

There is one case that we can leave bio in f2fs, result in hanging
page writeback waiter.

Thread A				Thread B
- f2fs_write_cache_pages
 - f2fs_submit_page_write
 page #0 cached in bio #0 of cold log
 - f2fs_submit_page_write
 page #1 cached in bio #1 of warm log
					- f2fs_write_cache_pages
					 - f2fs_submit_page_write
					 bio is full, submit bio #1 contain page #1
 - f2fs_submit_merged_write_cond(, page #1)
 fail to submit bio #0 due to page #1 is not in any cached bios.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch avoids BUG_ON when f2fs_get_meta_page_nofail got EIO during
xfstests/generic/475.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Remove the verbose license text from f2fs files and replace them with
SPDX tags.  This does not change the license of any of the code.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>