mm, slab: remove last vestiges of SLAB_MEM_SPREAD

Yes, yes, I know the slab people were planning on going slow and letting
every subsystem fight this thing on their own. But let's just rip off
the band-aid and get it over and done with. I don't want to see a
number of unnecessary pull requests just to get rid of a flag that no
longer has any meaning.

This was mainly done with a couple of 'sed' scripts and then some manual
cleanup of the end result.

Link: https://lore.kernel.org/all/CAHk-=wji0u+OOtmAOD-5JV3SXcRJF___k_+8XNKmak0yd5vW1Q@mail.gmail.com/
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

exfat: move freeing sbi, upcase table and dropping nls into rcu-delayed helper

That stuff can be accessed by ->d_hash()/->d_compare(); as it is, we have
a hard-to-hit UAF if rcu pathwalk manages to get into ->d_hash() on a filesystem
that is in process of getting shut down.

Besides, having nls and upcase table cleanup moved from ->put_super() towards
the place where sbi is freed makes for simpler failure exits.

Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

exfat: support create zero-size directory

This commit adds mount option 'zero_size_dir'. If this option
enabled, don't allocate a cluster to directory when creating
it, and set the directory size to 0.

On Windows, a cluster is allocated for a directory when it is
created, so the mount option is disabled by default.

Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Andy Wu <Andy.Wu@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>

exfat: add ioctls for accessing attributes

Add GET and SET attributes ioctls to enable attribute modification.
We already do this in FAT and a few userspace utils made for it would
benefit from this also working on exFAT, namely fatattr.

Signed-off-by: Jan Cincera <hcincera@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>

exfat: convert to new timestamp accessors

Convert to using the new inode timestamp accessor functions.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/20231004185347.80880-31-jlayton@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>

exfat: free the sbi and iocharset in ->kill_sb

As a rule of thumb everything allocated to the fs_context and moved into
the super_block should be freed by ->kill_sb so that the teardown
handling doesn't need to be duplicated between the fill_super error
path and put_super. Implement an exfat-specific kill_sb method to do
that and share the code with the mount contex free helper for the
mount error handling case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Message-Id: <20230809220545.1308228-11-hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>

exfat: don't RCU-free the sbi

There are no RCU critical sections for accessing any information in the
sbi, so drop the call_rcu indirection for freeing the sbi.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Message-Id: <20230809220545.1308228-10-hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>

exfat: convert to ctime accessor functions

In later patches, we're going to change how the inode's ctime field is
used. Switch to using accessor functions instead of raw accesses of
inode->i_ctime.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Message-Id: <20230705190309.579783-38-jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

exfat: fix inode->i_blocks for non-512 byte sector size device

inode->i_blocks is not real number of blocks, but 512 byte ones.

Fixes: 98d917047e8b ("exfat: add file operations")
Cc: stable@vger.kernel.org # v5.7+
Reported-by: Wang Yugui <wangyugui@e16-tech.com>
Tested-by: Wang Yugui <wangyugui@e16-tech.com>
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Andy Wu <Andy.Wu@sony.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>

exfat: Drop superfluous new line for error messages

exfat_err() adds the new line at the end of the message by itself,
hence the passed string shouldn't contain a new line. Drop the
superfluous newline letters in the error messages in a few places that
have been put mistakenly.

Reported-by: Joe Perches <joe@perches.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>

exfat: introduce mount option 'sys_tz'

EXFAT_TZ_VALID bit in {create,modify,access}_tz is corresponding to
OffsetValid field in exfat specification [1]. When this bit isn't
set, timestamps should be treated as having the same UTC offset as
the current local time.

Currently, there is an option 'time_offset' for users to specify the
UTC offset for this issue. This patch introduces a new mount option
'sys_tz' to use system timezone as time offset.

Link: [1] https://docs.microsoft.com/en-us/windows/win32/fileio/exfat-specification#74102-offsetvalid-field

Signed-off-by: Chung-Chiang Cheng <cccheng@synology.com>
Acked-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>

block: remove QUEUE_FLAG_DISCARD

Just use a non-zero max_discard_sectors as an indicator for discard
support, similar to what is done for write zeroes.

The only places where needs special attention is the RAID5 driver,
which must clear discard support for security reasons by default,
even if the default stacking rules would allow for it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> [drbd]
Acked-by: Jan Höppner <hoeppner@linux.ibm.com> [s390]
Acked-by: Coly Li <colyli@suse.de> [bcache]
Acked-by: David Sterba <dsterba@suse.com> [btrfs]
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220415045258.199825-25-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

exfat: do not clear VolumeDirty in writeback

Before this commit, VolumeDirty will be cleared first in
writeback if 'dirsync' or 'sync' is not enabled. If the power
is suddenly cut off after cleaning VolumeDirty but other
updates are not written, the exFAT filesystem will not be able
to detect the power failure in the next mount.

And VolumeDirty will be set again but not cleared when updating
the parent directory. It means that BootSector will be written at
least once in each write-back, which will shorten the life of the
device.

Reviewed-by: Andy Wu <Andy.Wu@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>

exfat: allow access to paths with trailing dots

The Linux kernel exfat driver currently unconditionally strips
trailing periods '.' from path components. This isdone intentionally,
loosely following Windows behaviour and specifications
which state:

#exFAT
The concatenated file name has the same set of illegal characters as
other FAT-based file systems (see Table 31).

#FAT
...
Leading and trailing spaces in a long name are ignored.
Leading and embedded periods are allowed in a name and are stored in
the long name. Trailing periods are ignored.

Note: Leading and trailing space ' ' characters are currently retained
by Linux kernel exfat, in conflict with the above specification.
On Windows 10, trailing and leading space ' ' characters are stripped
from the filenames.
Some implementations, such as fuse-exfat, don't perform path trailer
removal. When mounting images which contain trailing-dot paths, these
paths are unreachable, e.g.:

+ mount.exfat-fuse /dev/zram0 /mnt/test/
FUSE exfat 1.3.0
+ cd /mnt/test/
+ touch fuse_created_dots... ' fuse_created_spaces '
+ ls -l
total 0
-rwxrwxrwx 1 root 0 0 Aug 18 09:45 ' fuse_created_spaces '
-rwxrwxrwx 1 root 0 0 Aug 18 09:45 fuse_created_dots...
+ cd /
+ umount /mnt/test/
+ mount -t exfat /dev/zram0 /mnt/test
+ cd /mnt/test
+ ls -l
ls: cannot access 'fuse_created_dots...': No such file or directory
total 0
-rwxr-xr-x 1 root 0 0 Aug 18 09:45 ' fuse_created_spaces '
-????????? ? ? ? ? ? fuse_created_dots...
+ touch kexfat_created_dots... ' kexfat_created_spaces '
+ ls -l
ls: cannot access 'fuse_created_dots...': No such file or directory
total 0
-rwxr-xr-x 1 root 0 0 Aug 18 09:45 ' fuse_created_spaces '
-rwxr-xr-x 1 root 0 0 Aug 18 09:45 ' kexfat_created_spaces '
-????????? ? ? ? ? ? fuse_created_dots...
-rwxr-xr-x 1 root 0 0 Aug 18 09:45 kexfat_created_dots
+ cd /
+ umount /mnt/test/

This commit adds "keep_last_dots" mount option that controls whether or
not trailing periods '.' are stripped
from path components during file lookup or file creation.
This mount option can be used to access
paths with trailing periods and disallow creating files with names with
trailing periods. E.g. continuing from the previous example:

+ mount -t exfat -o keep_last_dots /dev/zram0 /mnt/test
+ cd /mnt/test
+ ls -l
total 0
-rwxr-xr-x 1 root 0 0 Aug 18 10:32 ' fuse_created_spaces '
-rwxr-xr-x 1 root 0 0 Aug 18 10:32 ' kexfat_created_spaces '
-rwxr-xr-x 1 root 0 0 Aug 18 10:32 fuse_created_dots...
-rwxr-xr-x 1 root 0 0 Aug 18 10:32 kexfat_created_dots

+ echo > kexfat_created_dots_again...
sh: kexfat_created_dots_again...: Invalid argument

Link: https://bugzilla.suse.com/show_bug.cgi?id=1188964
Link: https://lore.kernel.org/linux-fsdevel/003b01d755e4$31fb0d80$95f12880$
@samsung.com/
Link: https://docs.microsoft.com/en-us/windows/win32/fileio/exfat-specification
Suggested-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Vasant Karasulli <vkarasulli@suse.de>
Co-developed-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>

fs: allocate inode by using alloc_inode_sb()

The inode allocation is supposed to use alloc_inode_sb(), so convert
kmem_cache_alloc() of all filesystems to alloc_inode_sb().

Link: https://lkml.kernel.org/r/20220228122126.37293-5-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Theodore Ts'o <tytso@mit.edu> [ext4]
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Alex Shi <alexs@kernel.org>
Cc: Anna Schumaker <Anna.Schumaker@Netapp.com>
Cc: Chao Yu <chao@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Fam Zheng <fam.zheng@bytedance.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kari Argillander <kari.argillander@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

exfat: move super block magic number to magic.h

Move exfat superblock magic number from local definition to magic.h.
It is also needed by userspace programs that call fstatfs().

Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>

exfat: fix i_blocks for files truncated over 4 GiB

In exfat_truncate(), the computation of inode->i_blocks is wrong if
the file is larger than 4 GiB because a 32-bit variable is used as a
mask. This is fixed and simplified by using round_up().

Also fix the same buggy computation in exfat_read_root() and another
(correct) one in exfat_fill_inode(). The latter was fixed another way
last month but can be simplified by using round_up() as well. See:

commit 0c336d6e33f4 ("exfat: fix incorrect loading of i_blocks for
large files")

Fixes: 98d917047e8b ("exfat: add file operations")
Cc: stable@vger.kernel.org # v5.7+
Suggested-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Christophe Vu-Brugier <christophe.vu-brugier@seagate.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>

exfat: reuse exfat_inode_info variable instead of calling EXFAT_I()

Also add a local "struct exfat_inode_info *ei" variable to
exfat_truncate() to simplify the code.

Signed-off-by: Christophe Vu-Brugier <christophe.vu-brugier@seagate.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>

exfat: avoid incorrectly releasing for root inode

In d_make_root, when we fail to allocate dentry for root inode,
we will iput root inode and returned value is NULL in this function.

So we do not need to release this inode again at d_make_root's caller.

Signed-off-by: Chen Li <chenli@uniontech.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>

exfat: introduce bitmap_lock for cluster bitmap access

s_lock which is for protecting concurrent access of file operations is
too huge for cluster bitmap protection, so introduce a new bitmap_lock
to narrow the lock range if only need to access cluster bitmap.

Signed-off-by: Hyeongseok Kim <hyeongseok@gmail.com>
Acked-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>

exfat: fix shift-out-of-bounds in exfat_fill_super()

syzbot reported a warning which could cause shift-out-of-bounds issue.

Call Trace:
__dump_stack lib/dump_stack.c:79 [inline]
dump_stack+0x183/0x22e lib/dump_stack.c:120
ubsan_epilogue lib/ubsan.c:148 [inline]
__ubsan_handle_shift_out_of_bounds+0x432/0x4d0 lib/ubsan.c:395
exfat_read_boot_sector fs/exfat/super.c:471 [inline]
__exfat_fill_super fs/exfat/super.c:556 [inline]
exfat_fill_super+0x2acb/0x2d00 fs/exfat/super.c:624
get_tree_bdev+0x406/0x630 fs/super.c:1291
vfs_get_tree+0x86/0x270 fs/super.c:1496
do_new_mount fs/namespace.c:2881 [inline]
path_mount+0x1937/0x2c50 fs/namespace.c:3211
do_mount fs/namespace.c:3224 [inline]
__do_sys_mount fs/namespace.c:3432 [inline]
__se_sys_mount+0x2f9/0x3b0 fs/namespace.c:3409
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9

exfat specification describe sect_per_clus_bits field of boot sector
could be at most 25 - sect_size_bits and at least 0. And sect_size_bits
can also affect this calculation, It also needs validation.
This patch add validation for sect_per_clus_bits and sect_size_bits
field of boot sector.

Fixes: 719c1e182916 ("exfat: add super block operations")
Cc: stable@vger.kernel.org # v5.9+
Reported-by: syzbot+da4fe66aaadd3c2e2d1c@syzkaller.appspotmail.com
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>

exfat: remove 'rwoffset' in exfat_inode_info

Remove 'rwoffset' in exfat_inode_info and replace it with the parameter of
exfat_readdir().
Since rwoffset is referenced only by exfat_readdir(), it is not necessary
a exfat_inode_info's member.
Also, change cpos to point to the next of entry-set, and return the index
of dir-entry via dir_entry->entry.

Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com>
Acked-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>

exfat: fix use of uninitialized spinlock on error path

syzbot reported warning message:

Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1d6/0x29e lib/dump_stack.c:118
register_lock_class+0xf06/0x1520 kernel/locking/lockdep.c:893
__lock_acquire+0xfd/0x2ae0 kernel/locking/lockdep.c:4320
lock_acquire+0x148/0x720 kernel/locking/lockdep.c:5029
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151
spin_lock include/linux/spinlock.h:354 [inline]
exfat_cache_inval_inode+0x30/0x280 fs/exfat/cache.c:226
exfat_evict_inode+0x124/0x270 fs/exfat/inode.c:660
evict+0x2bb/0x6d0 fs/inode.c:576
exfat_fill_super+0x1e07/0x27d0 fs/exfat/super.c:681
get_tree_bdev+0x3e9/0x5f0 fs/super.c:1342
vfs_get_tree+0x88/0x270 fs/super.c:1547
do_new_mount fs/namespace.c:2875 [inline]
path_mount+0x179d/0x29e0 fs/namespace.c:3192
do_mount fs/namespace.c:3205 [inline]
__do_sys_mount fs/namespace.c:3413 [inline]
__se_sys_mount+0x126/0x180 fs/namespace.c:3390
do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9

If exfat_read_root() returns an error, spinlock is used in
exfat_evict_inode() without initialization. This patch combines
exfat_cache_init_inode() with exfat_inode_init_once() to initialize
spinlock by slab constructor.

Fixes: c35b6810c495 ("exfat: add exfat cache")
Cc: stable@vger.kernel.org # v5.7+
Reported-by: syzbot <syzbot+b91107320911a26c9a95@syzkaller.appspotmail.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>

[PATCH] reduce boilerplate in fsid handling

Get rid of boilerplate in most of ->statfs()
instances...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

exfat: retain 'VolumeFlags' properly

MediaFailure and VolumeDirty should be retained if these are set before
mounting.

In '3.1.13.3 Media Failure Field' of exfat specification describe:

If, upon mounting a volume, the value of this field is 1,
implementations which scan the entire volume for media failures and
record all failures as "bad" clusters in the FAT (or otherwise resolve
media failures) may clear the value of this field to 0.

Therefore, We should not clear MediaFailure without scanning volume.

In '8.1 Recommended Write Ordering' of exfat specification describe:

Clear the value of the VolumeDirty field to 0, if its value prior to
the first step was 0.

Therefore, We should not clear VolumeDirty after mounting.
Also rename ERR_MEDIUM to MEDIA_FAILURE.

Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>

exfat: remove EXFAT_SB_DIRTY flag

This flag is set/reset in exfat_put_super()/exfat_sync_fs()
to avoid sync_blockdev().
- exfat_put_super():
Before calling this, the VFS has already called sync_filesystem(),
so sync is never performed here.
- exfat_sync_fs():
After calling this, the VFS calls sync_blockdev(), so, it is meaningless
to check EXFAT_SB_DIRTY or to bypass sync_blockdev() here.

Remove the EXFAT_SB_DIRTY check to ensure synchronization.
And remove the code related to the flag.

Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>

exfat: call sync_filesystem for read-only remount

We need to commit dirty metadata and pages to disk
before remounting exfat as read-only.

This fixes a failure in xfstests generic/452

generic/452 does the following:
cp something <exfat>/
mount -o remount,ro <exfat>

the <exfat>/something is corrupted. because while
exfat is remounted as read-only, exfat doesn't
have a chance to commit metadata and
vfs invalidates page caches in a block device.

Signed-off-by: Hyunchul Lee <hyc.lee@gmail.com>
Acked-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>

exfat: fix memory leak in exfat_parse_param()

butt3rflyh4ck reported memory leak found by syzkaller.

A param->string held by exfat_mount_options.

BUG: memory leak

unreferenced object 0xffff88801972e090 (size 8):
comm "syz-executor.2", pid 16298, jiffies 4295172466 (age 14.060s)
hex dump (first 8 bytes):
6b 6f 69 38 2d 75 00 00 koi8-u..
backtrace:
[<000000005bfe35d6>] kstrdup+0x36/0x70 mm/util.c:60
[<0000000018ed3277>] exfat_parse_param+0x160/0x5e0
fs/exfat/super.c:276
[<000000007680462b>] vfs_parse_fs_param+0x2b4/0x610
fs/fs_context.c:147
[<0000000097c027f2>] vfs_parse_fs_string+0xe6/0x150
fs/fs_context.c:191
[<00000000371bf78f>] generic_parse_monolithic+0x16f/0x1f0
fs/fs_context.c:231
[<000000005ce5eb1b>] do_new_mount fs/namespace.c:2812 [inline]
[<000000005ce5eb1b>] do_mount+0x12bb/0x1b30 fs/namespace.c:3141
[<00000000b642040c>] __do_sys_mount fs/namespace.c:3350 [inline]
[<00000000b642040c>] __se_sys_mount fs/namespace.c:3327 [inline]
[<00000000b642040c>] __x64_sys_mount+0x18f/0x230 fs/namespace.c:3327
[<000000003b024e98>] do_syscall_64+0xf6/0x7d0
arch/x86/entry/common.c:295
[<00000000ce2b698c>] entry_SYSCALL_64_after_hwframe+0x49/0xb3

exfat_free() should call exfat_free_iocharset(), to prevent a leak
in case we fail after parsing iocharset= but before calling
get_tree_bdev().

Additionally, there's no point copying param->string in
exfat_parse_param() - just steal it, leaving NULL in param->string.
That's independent from the leak or fix thereof - it's simply
avoiding an extra copy.

Fixes: 719c1e182916 ("exfat: add super block operations")
Cc: stable@vger.kernel.org # v5.7
Reported-by: butt3rflyh4ck <butterflyhuangxx@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>

exfat: add boot region verification

Add Boot-Regions verification specified in exFAT specification.
Note that the checksum type is strongly related to the raw structure,
so the'u32 'type is used to clarify the number of bits.

Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>

exfat: separate the boot sector analysis

Separate the boot sector analysis to read_boot_sector().
And add a check for the fs_name field.
Furthermore, add a strict consistency check, because overlapping areas
can cause serious corruption.

Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>

exfat: redefine PBR as boot_sector

Aggregate PBR related definitions and redefine as "boot_sector" to comply
with the exFAT specification.
And, rename variable names including 'pbr'.

Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>

exfat: remove the assignment of 0 to bool variable

There is no need to init 'sync' in exfat_set_vol_flags().
This also fixes the following coccicheck warning:

fs/exfat/super.c:104:6-10: WARNING: Assignment of 0/1 to bool variable

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>

exfat: Use a more common logging style

Remove the direct use of KERN_<LEVEL> in functions by creating
separate exfat_<level> macros.

Miscellanea:

o Remove several unnecessary terminating newlines in formats
o Realign arguments and fit to 80 columns where appropriate

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>

exfat: add the dummy mount options to be backward compatible with staging/exfat

As Ubuntu and Fedora release new version used kernel version equal to or
higher than v5.4, They started to support kernel exfat filesystem.

Linus reported a mount error with new version of exfat on Fedora:

exfat: Unknown parameter 'namecase'

This is because there is a difference in mount option between old
staging/exfat and new exfat. And utf8, debug, and codepage options as
well as namecase have been removed from new exfat.

This patch add the dummy mount options as deprecated option to be
backward compatible with old one.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

exfat: truncate atimes to 2s granularity

The timestamp for access_time has double seconds granularity(There is no
10msIncrement field for access_time unlike create/modify_time).
exfat's atimes are restricted to only 2s granularity so after
we set an atime, round it down to the nearest 2s and set the
sub-second component of the timestamp to 0.

Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>

exfat: properly set s_time_gran

The s_time_gran superblock field indicates the on-disk nanosecond
granularity of timestamps, and for exfat that seems to be 10ms, so
set s_time_gran to 10000000ns. Without this, in-memory timestamps
change when they get re-read from disk.

Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>

exfat: remove 'bps' mount-option

remount fails because exfat_show_options() returns unsupported
option 'bps'.
> # mount -o ro,remount
> exfat: Unknown parameter 'bps'

To fix the problem, just remove 'bps' option from exfat_show_options().

Signed-off-by: Tetsuhiro Kohada <Kohada.Tetsuhiro@dc.MitsubishiElectric.co.jp>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>

exfat: Unify access to the boot sector

Unify access to boot sector via 'sbi->pbr_bh'.
This fixes vol_flags inconsistency at read failed in fs_set_vol_flags(),
and buffer_head leak in __exfat_fill_super().

Signed-off-by: Tetsuhiro Kohada <Kohada.Tetsuhiro@dc.MitsubishiElectric.co.jp>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>

exfat: add missing MODULE_ALIAS_FS()

This adds the necessary MODULE_ALIAS_FS() to exfat so the module gets
automatically loaded when an exfat filesystem is mounted.

Signed-off-by: Thomas Backlund <tmb@mageia.org>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>

exfat: Fix discard support

Discard support was always unconditionally disabled. Now it is disabled
only in the case when blk_queue_discard() returns false.

Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>

exfat: update file system parameter handling

Al Viro recently reworked the way file system parameters are handled
Update super.c to work with it in linux-next 20200203.

Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

exfat: add super block operations

This adds the implementation of superblock operations for exfat.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Sungjong Seo <sj1557.seo@samsung.com>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>