=============================================================================
 BUG discard_cmd (Tainted: G    B      OE  ): Objects remaining in discard_cmd on __kmem_cache_shutdown()
 -----------------------------------------------------------------------------

 INFO: Slab 0xffffe1ac481d22c0 objects=36 used=2 fp=0xffff936b4748bf50 flags=0x2ffff0000000100
 Call Trace:
  dump_stack+0x63/0x87
  slab_err+0xa1/0xb0
  __kmem_cache_shutdown+0x183/0x390
  shutdown_cache+0x14/0x110
  kmem_cache_destroy+0x195/0x1c0
  f2fs_destroy_segment_manager_caches+0x21/0x40 [f2fs]
  exit_f2fs_fs+0x35/0x641 [f2fs]
  SyS_delete_module+0x155/0x230
  ? vtime_user_exit+0x29/0x70
  do_syscall_64+0x6e/0x160
  entry_SYSCALL64_slow_path+0x25/0x25

 INFO: Object 0xffff936b4748b000 @offset=0
 INFO: Object 0xffff936b4748b070 @offset=112
 kmem_cache_destroy discard_cmd: Slab cache still has objects
 Call Trace:
  dump_stack+0x63/0x87
  kmem_cache_destroy+0x1b4/0x1c0
  f2fs_destroy_segment_manager_caches+0x21/0x40 [f2fs]
  exit_f2fs_fs+0x35/0x641 [f2fs]
  SyS_delete_module+0x155/0x230
  do_syscall_64+0x6e/0x160
  entry_SYSCALL64_slow_path+0x25/0x25

Recovery can cache discard commands, so in error path of fill_super(),
we need give a chance to handle them, otherwise it will lead to leak
of discard_cmd slab cache.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

On a quota disabled image, with fault injection, SBI_QUOTA_NEED_REPAIR
will be set incorrectly in error path of f2fs_evict_inode(), fix it.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

As reported in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=204193

A null pointer dereference bug is triggered in f2fs under kernel-5.1.3.

 kasan_report.cold+0x5/0x32
 f2fs_write_end_io+0x215/0x650
 bio_endio+0x26e/0x320
 blk_update_request+0x209/0x5d0
 blk_mq_end_request+0x2e/0x230
 lo_complete_rq+0x12c/0x190
 blk_done_softirq+0x14a/0x1a0
 __do_softirq+0x119/0x3e5
 irq_exit+0x94/0xe0
 call_function_single_interrupt+0xf/0x20

During umount, we will access NULL sbi->node_inode pointer in
f2fs_write_end_io():

	f2fs_bug_on(sbi, page->mapping == NODE_MAPPING(sbi) &&
				page->index != nid_of_node(page));

The reason is if disable_checkpoint mount option is on, meta dirty
pages can remain during umount, and then be flushed by iput() of
meta_inode, however node_inode has been iput()ed before
meta_inode's iput().

Since checkpoint is disabled, all meta/node datas are useless and
should be dropped in next mount, so in umount, let's adjust
drop_inode() to give a hint to iput_final() to drop all those dirty
datas correctly.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If IO alignment feature is turned on after remount, we didn't
initialize mempool of it, it turns out we will encounter panic
during IO submission due to access NULL mempool pointer.

This feature should be set only at mount time, so simply deny
configuring during remount.

This fixes bug reported in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=204135Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Since 07173c3e ("block: enable multipage bvecs"), one bio vector
can store multi pages, so that we can not calculate max IO size of
bio as PAGE_SIZE * bio->bi_max_vecs. However IO alignment feature of
f2fs always has that assumption, so finally, it may cause panic during
IO submission as below stack.

 kernel BUG at fs/f2fs/data.c:317!
 RIP: 0010:__submit_merged_bio+0x8b0/0x8c0
 Call Trace:
  f2fs_submit_page_write+0x3cd/0xdd0
  do_write_page+0x15d/0x360
  f2fs_outplace_write_data+0xd7/0x210
  f2fs_do_write_data_page+0x43b/0xf30
  __write_data_page+0xcf6/0x1140
  f2fs_write_cache_pages+0x3ba/0xb40
  f2fs_write_data_pages+0x3dd/0x8b0
  do_writepages+0xbb/0x1e0
  __writeback_single_inode+0xb6/0x800
  writeback_sb_inodes+0x441/0x910
  wb_writeback+0x261/0x650
  wb_workfn+0x1f9/0x7a0
  process_one_work+0x503/0x970
  worker_thread+0x7d/0x820
  kthread+0x1ad/0x210
  ret_from_fork+0x35/0x40

This patch adds one extra condition to check left space in bio while
trying merging page to bio, to avoid panic.

This bug was reported in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=204043Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Wrap merge condition into function for readability, no logic change.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch fixes livelock in the below call path when writing swap pages.

[46374.617256] c2    701  __switch_to+0xe4/0x100
[46374.617265] c2    701  __schedule+0x80c/0xbc4
[46374.617273] c2    701  schedule+0x74/0x98
[46374.617281] c2    701  rwsem_down_read_failed+0x190/0x234
[46374.617291] c2    701  down_read+0x58/0x5c
[46374.617300] c2    701  f2fs_map_blocks+0x138/0x9a8
[46374.617310] c2    701  get_data_block_dio_write+0x74/0x104
[46374.617320] c2    701  __blockdev_direct_IO+0x1350/0x3930
[46374.617331] c2    701  f2fs_direct_IO+0x55c/0x8bc
[46374.617341] c2    701  __swap_writepage+0x1d0/0x3e8
[46374.617351] c2    701  swap_writepage+0x44/0x54
[46374.617360] c2    701  shrink_page_list+0x140/0xe80
[46374.617371] c2    701  shrink_inactive_list+0x510/0x918
[46374.617381] c2    701  shrink_node_memcg+0x2d4/0x804
[46374.617391] c2    701  shrink_node+0x10c/0x2f8
[46374.617400] c2    701  do_try_to_free_pages+0x178/0x38c
[46374.617410] c2    701  try_to_free_pages+0x348/0x4b8
[46374.617419] c2    701  __alloc_pages_nodemask+0x7f8/0x1014
[46374.617429] c2    701  pagecache_get_page+0x184/0x2cc
[46374.617438] c2    701  f2fs_new_node_page+0x60/0x41c
[46374.617449] c2    701  f2fs_new_inode_page+0x50/0x7c
[46374.617460] c2    701  f2fs_init_inode_metadata+0x128/0x530
[46374.617472] c2    701  f2fs_add_inline_entry+0x138/0xd64
[46374.617480] c2    701  f2fs_do_add_link+0xf4/0x178
[46374.617488] c2    701  f2fs_create+0x1e4/0x3ac
[46374.617497] c2    701  path_openat+0xdc0/0x1308
[46374.617507] c2    701  do_filp_open+0x78/0x124
[46374.617516] c2    701  do_sys_open+0x134/0x248
[46374.617525] c2    701  SyS_openat+0x14/0x20
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

The kernel mount_block_root() function expects -EACESS or -EINVAL for a
unmountable filesystem when trying to mount the root with different
filesystem types.

However, in 5.3-rc1 the behavior when F2FS code cannot find valid block
changed to return -EFSCORRUPTED(-EUCLEAN), and this error code makes
mount_block_root() fail when trying to probe F2FS.

When the magic number of the superblock mismatches, it has a high
probability that it's just not a F2FS. In this case return -EINVAL seems
to be a better result, and this return value can make mount_block_root()
probing work again.

Return -EINVAL when the superblock has magic mismatch, -EFSCORRUPTED in
other cases (the magic matches but the superblock cannot be recognized).

Fixes: 10f966bb ("f2fs: use generic EFSBADCRC/EFSCORRUPTED")
Signed-off-by: NIcenowy Zheng <icenowy@aosc.io>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

f2fs_allocate_data_block() invalidates old block address and enable new block
address. Then, if we try to read old block by f2fs_submit_page_bio(), it will
give WARN due to reading invalid blocks.

Let's make the order sanely back.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

migrate_page_move_mapping() doesn't use the mode argument.  Remove it
and update callers accordingly.

Link: http://lkml.kernel.org/r/20190508210301.8472-1-keith.busch@intel.comSigned-off-by: NKeith Busch <keith.busch@intel.com>
Reviewed-by: NZi Yan <ziy@nvidia.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Now that f2fs_ioc_setflags() and f2fs_ioc_fssetxattr() call the VFS
helper functions which check for permission to change the immutable and
append-only flags, it's no longer needed to do this check in
f2fs_setflags_common() too.  So remove it.

This is based on a patch from Darrick Wong, but reworked to apply after
commit 36098557 ("f2fs: separate f2fs i_flags from fs_flags and ext4
i_flags").

Originally-from: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NEric Biggers <ebiggers@google.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Make the f2fs implementation of FS_IOC_FSSETXATTR use the new VFS helper
function vfs_ioc_fssetxattr_check(), and remove the project quota check
since it's now done by the helper function.

This is based on a patch from Darrick Wong, but reworked to apply after
commit 36098557 ("f2fs: separate f2fs i_flags from fs_flags and ext4
i_flags").

Originally-from: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NEric Biggers <ebiggers@google.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Make the f2fs implementation of FS_IOC_SETFLAGS use the new VFS helper
function vfs_ioc_setflags_prepare().

This is based on a patch from Darrick Wong, but reworked to apply after
commit 36098557 ("f2fs: separate f2fs i_flags from fs_flags and ext4
i_flags").

Originally-from: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NEric Biggers <ebiggers@google.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Only GFP_KERNEL and GFP_NOIO are used with blkdev_report_zones(). In
preparation of using vmalloc() for large report buffer and zone array
allocations used by this function, remove its "gfp_t gfp_mask" argument
and rely on the caller context to use memalloc_noio_save/restore() where
necessary (block layer zone revalidation and dm-zoned I/O error path).
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NDamien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

As Park Ju Hyung suggested:

"I'd like to suggest to write down an actual version of f2fs-tools
here as we've seen older versions of fsck doing even more damage
and the users might not have the latest f2fs-tools installed."

This patch give a more detailed info of how we fix such corruption
to user to avoid damageable repair with low version fsck.
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>

blkoff_off might over 512 due to fs corrupt or security
vulnerability. That should be checked before being using.

Use ENTRIES_IN_SUM to protect invalid value in cur_data_blkoff.
Signed-off-by: NOcean Chen <oceanchen@google.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In umount, we give an constand time to handle pending discard, previously,
in __issue_discard_cmd() we missed to check timeout condition in loop,
result in delaying long time, fix it.
Signed-off-by: NHeng Xiao <heng.xiao@unisoc.com>
[Chao Yu: add commit message]
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch allows users to pin files.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

wbc_account_io() does a very specific job - try to see which cgroup is
actually dirtying an inode and transfer its ownership to the majority
dirtier if needed.  The name is too generic and confusing.  Let's
rename it to something more specific.
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch allows fallocate to allocate physical blocks for pinned file.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

The discard thread should issue upto dpolicy->max_requests at once
and wait for all those discard requests at once it reaches
dpolicy->max_requests. It should then sleep for dpolicy->min_interval
timeout before issuing the next batch of discard requests. But in the
current code of is_idle(), it checks for dcc_info->queued_discard and
aborts issuing the discard batch of max_requests. This
dcc_info->queued_discard will be true always once one discard command
is issued.

It is thus resulting into this type of discard request pattern -

- Issue discard request#1
- is_idle() returns false, discard thread waits for request#1 and then
  sleeps for min_interval 50ms.
- Issue discard request#2
- is_idle() returns false, discard thread waits for request#2 and then
  sleeps for min_interval 50ms.
- and so on for all other discard requests, assuming f2fs is idle w.r.t
  other conditions.

With this fix, the pattern will look like this -

- Issue discard request#1
- Issue discard request#2
  and so on upto max_requests of 8
- Issue discard request#8
- wait for min_interval 50ms.
Signed-off-by: NSahitya Tummala <stummala@codeaurora.org>
Reviewed-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>

If xattr is corrupted, let's print kernel message and set SBI_NEED_FSCK
for further repair.
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>

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>

Replace the open-coded divisions with round-up by calls to the
DIV_ROUND_UP() helper macro.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

As Pavel reported, once we detect filesystem inconsistency in
f2fs_inplace_write_data(), it will be better to print kernel message as
we did in other places.
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>

No logic change.
Signed-off-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>

It doesn't make any sense to have project inherit bits
for regular files, even though this won't cause any
problem, but it is better fix this.

Cc: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: NWang Shilong <wshilong@ddn.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

f2fs copied all the on-disk i_flags from ext4, and along with it the
assumption that the on-disk i_flags are the same as the bits used by
FS_IOC_GETFLAGS and FS_IOC_SETFLAGS.  This is problematic because
reserving an on-disk inode flag in either filesystem's i_flags or in
these ioctls effectively reserves it in all the other places too.  In
fact, most of the "f2fs i_flags" are not used by f2fs at all.

Fix this by separating f2fs's i_flags from the ioctl bits and ext4's
i_flags.

In the process, un-reserve all "f2fs i_flags" that aren't actually
supported by f2fs.  This included various flags that were not settable
at all, as well as various flags that were settable by FS_IOC_SETFLAGS
but didn't actually do anything.

There's a slight chance we'll need to add some flag(s) back to
FS_IOC_SETFLAGS in order to avoid breaking users who expect f2fs to
accept some random flag(s).  But hopefully such users don't exist.
Signed-off-by: NEric Biggers <ebiggers@google.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

The kobj_type default_attrs field is being replaced by the
default_groups field. Replace the default_attrs fields in f2fs_sb_ktype
and f2fs_feat_ktype with default_groups. Use the ATTRIBUTE_GROUPS macro
to create f2fs_groups and f2fs_feat_groups.

Fixes: fef4129e ("f2fs: fix to be aware discard/preflush/dio command in is_idle()")
Signed-off-by: NKimberly Brown <kimbrownkd@gmail.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

The kobj_type default_attrs field is being replaced by the
default_groups field. Replace the default_attrs fields in f2fs_sb_ktype
and f2fs_feat_ktype with default_groups. Use the ATTRIBUTE_GROUPS macro
to create f2fs_groups and f2fs_feat_groups.
Signed-off-by: NKimberly Brown <kimbrownkd@gmail.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This extends the checkpoint option to allow checkpoint=disable:%u[%]
This allows you to specify what how much of the disk you are willing
to lose access to while mounting with checkpoint=disable. If the amount
lost would be higher, the mount will return -EAGAIN. This can be given
as a percent of total space, or in blocks.

Currently, we need to run garbage collection until the amount of holes
is smaller than the OVP space. With the new option, f2fs can mark
space as unusable up front instead of requiring garbage collection until
the number of holes is small enough.
Signed-off-by: NDaniel Rosenberg <drosen@google.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Fixes possible underflows when dealing with unusable blocks.
Signed-off-by: NDaniel Rosenberg <drosen@google.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

On a remount, you can currently set root reserved if it was not
previously set. This can cause an underflow if reserved has been set to
a very high value, since then root reserved + current reserved could be
greater than user_block_count. inc_valid_block_count later subtracts out
these values from user_block_count, causing an underflow.
Signed-off-by: NDaniel Rosenberg <drosen@google.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

The existing threshold for allowable holes at checkpoint=disable time is
too high. The OVP space contains reserved segments, which are always in
the form of free segments. These must be subtracted from the OVP value.

The current threshold is meant to be the maximum value of holes of a
single type we can have and still guarantee that we can fill the disk
without failing to find space for a block of a given type.

If the disk is full, ignoring current reserved, which only helps us,
the amount of unused blocks is equal to the OVP area. Of that, there
are reserved segments, which must be free segments, and the rest of the
ovp area, which can come from either free segments or holes. The maximum
possible amount of holes is OVP-reserved.

Now, consider the disk when mounting with checkpoint=disable.
We must be able to fill all available free space with either data or
node blocks. When we start with checkpoint=disable, holes are locked to
their current type. Say we have H of one type of hole, and H+X of the
other. We can fill H of that space with arbitrary typed blocks via SSR.
For the remaining H+X blocks, we may not have any of a given block type
left at all. For instance, if we were to fill the disk entirely with
blocks of the type with fewer holes, the H+X blocks of the opposite type
would not be used. If H+X > OVP-reserved, there would be more holes than
could possibly exist, and we would have failed to find a suitable block
earlier on, leading to a crash in update_sit_entry.

If H+X <= OVP-reserved, then the holes end up effectively masked by the OVP
region in this case.
Signed-off-by: NDaniel Rosenberg <drosen@google.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

make C=2 CHECKFLAGS="-D__CHECK_ENDIAN__"

CHECK   dir.c
dir.c:842:50: warning: cast from restricted __le32
CHECK   node.c
node.c:2759:40: warning: restricted __le32 degrades to integer
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Fix f2fs_show_options to show nodiscard mount option.
Signed-off-by: NSahitya Tummala <stummala@codeaurora.org>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>