nilfs2: fix failure to detect DAT corruption in btree and direct mappings

Patch series "nilfs2: fix kernel bug at submit_bh_wbc()".

This resolves a kernel BUG reported by syzbot. Since there are two
flaws involved, I've made each one a separate patch.

The first patch alone resolves the syzbot-reported bug, but I think
both fixes should be sent to stable, so I've tagged them as such.


This patch (of 2):

Syzbot has reported a kernel bug in submit_bh_wbc() when writing file data
to a nilfs2 file system whose metadata is corrupted.

There are two flaws involved in this issue.

The first flaw is that when nilfs_get_block() locates a data block using
btree or direct mapping, if the disk address translation routine
nilfs_dat_translate() fails with internal code -ENOENT due to DAT metadata
corruption, it can be passed back to nilfs_get_block(). This causes
nilfs_get_block() to misidentify an existing block as non-existent,
causing both data block lookup and insertion to fail inconsistently.

The second flaw is that nilfs_get_block() returns a successful status in
this inconsistent state. This causes the caller __block_write_begin_int()
or others to request a read even though the buffer is not mapped,
resulting in a BUG_ON check for the BH_Mapped flag in submit_bh_wbc()
failing.

This fixes the first issue by changing the return value to code -EINVAL
when a conversion using DAT fails with code -ENOENT, avoiding the
conflicting condition that leads to the kernel bug described above. Here,
code -EINVAL indicates that metadata corruption was detected during the
block lookup, which will be properly handled as a file system error and
converted to -EIO when passing through the nilfs2 bmap layer.

Link: https://lkml.kernel.org/r/20240313105827.5296-1-konishi.ryusuke@gmail.com
Link: https://lkml.kernel.org/r/20240313105827.5296-2-konishi.ryusuke@gmail.com
Fixes: c3a7abf06ce7 ("nilfs2: support contiguous lookup of blocks")
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+cfed5b56649bddf80d6e@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=cfed5b56649bddf80d6e
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

nilfs2: initialize "struct nilfs_binfo_dat"->bi_pad field

nilfs_btree_assign_p() and nilfs_direct_assign_p() are not initializing
"struct nilfs_binfo_dat"->bi_pad field, causing uninit-value reports when
being passed to CRC function.

Link: https://lkml.kernel.org/r/20230326152146.15872-1-konishi.ryusuke@gmail.com
Reported-by: syzbot <syzbot+048585f3f4227bb2b49b@syzkaller.appspotmail.com>
Link: https://syzkaller.appspot.com/bug?extid=048585f3f4227bb2b49b
Reported-by: Dipanjan Das <mail.dipanjan.das@gmail.com>
Link: https://lkml.kernel.org/r/CANX2M5bVbzRi6zH3PTcNE_31TzerstOXUa9Bay4E6y6dX23_pg@mail.gmail.com
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

nilfs2: remove filenames from file comments

Remove filenames that are not particularly useful in file comments, and
suppress checkpatch warnings

WARNING: It's generally not useful to have the filename in the file

Link: https://lkml.kernel.org/r/1635151862-11547-3-git-send-email-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Qing Wang <wangqing@vivo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: use a more common logging style

Add macros for nilfs_<level>(sb, fmt, ...) and convert the uses of
'nilfs_msg(sb, KERN_<LEVEL>, ...)' to 'nilfs_<level>(sb, ...)' so nilfs2
uses a logging style more like the typical kernel logging style.

Miscellanea:

o Realign arguments for these uses

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/1595860111-3920-4-git-send-email-konishi.ryusuke@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: convert to SPDX license tags

Remove the verbose license text from NILFS2 files and replace them with
SPDX tags. This does not change the license of any of the code.

Link: http://lkml.kernel.org/r/1535624528-5982-1-git-send-email-konishi.ryusuke@lab.ntt.co.jp
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: reduce bare use of printk() with nilfs_msg()

Replace most use of printk() in nilfs2 implementation with nilfs_msg(),
and reduce the following checkpatch.pl warning:

"WARNING: Prefer [subsystem eg: netdev]_crit([subsystem]dev, ...
then dev_crit(dev, ... then pr_crit(... to printk(KERN_CRIT ..."

This patch also fixes a minor checkpatch warning "WARNING: quoted string
split across lines" that often accompanies the prior warning, and amends
message format as needed.

Link: http://lkml.kernel.org/r/1464875891-5443-5-git-send-email-konishi.ryusuke@lab.ntt.co.jp
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: remove unnecessary else after return or break

This fixes the checkpatch.pl warning that suggests else is not
generally useful after a break or return.

Link: http://lkml.kernel.org/r/1462886671-3521-6-git-send-email-konishi.ryusuke@lab.ntt.co.jp
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: avoid bare use of 'unsigned'

This fixes checkpatch.pl warning "WARNING: Prefer 'unsigned int' to
bare use of 'unsigned'".

Link: http://lkml.kernel.org/r/1462886671-3521-5-git-send-email-konishi.ryusuke@lab.ntt.co.jp
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: clean up old e-mail addresses

E-mail addresses of osrg.net domain are no longer available. This
removes them from authorship notices and prevents reporters from being
confused.

Link: http://lkml.kernel.org/r/1461935747-10380-5-git-send-email-konishi.ryusuke@lab.ntt.co.jp
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: remove FSF mailing address from GPL notices

This removes the extra paragraph which mentions FSF address in GPL
notices from source code of nilfs2 and avoids the checkpatch.pl error
related to it.

Link: http://lkml.kernel.org/r/1461935747-10380-4-git-send-email-konishi.ryusuke@lab.ntt.co.jp
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: add bmap function to seek a valid key

Add a new bmap function, nilfs_bmap_seek_key(), which seeks a valid
entry and returns its key starting from a given key. This function
can be used to skip hole blocks efficiently.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: record used amount of each checkpoint in checkpoint list

This records the number of used blocks per checkpoint in each
checkpoint entry of cpfile. Even though userland tools can get the
block count via nilfs_get_cpinfo ioctl, it was not updated by the
nilfs2 kernel code. This fixes the issue and makes it available for
userland tools to calculate used amount per checkpoint.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Jiro SEKIBA <jir@unicus.jp>

nilfs2: remove redundant pointer checks in bmap lookup functions

nilfs_bmap_lookup and its variants are supposed to take a valid
pointer argument to return a block address, thus pointer checks in
nilfs_btree_lookup and nilfs_direct_lookup are needless.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

nilfs2: unify bmap set_target_v operations

This unifies two similar functions nilfs_btree_set_target_v and
nilfs_direct_set_target_v into one, nilfs_bmap_set_target_v.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

nilfs2: get rid of nilfs_direct uses

This replaces all uses of nilfs_direct struct in implementation of
direct mapping with nilfs_bmap struct.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

nilfs2: remove constant qualifier from argument of bmap propagate

The first argument of bops->bop_propagate operation takes a constant
qualifier, and causes compilation error when removed cast to pointer
of nilfs_btree structure type. This fixes the issue to prepare for
succesive removal of nilfs_btree struct.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

nilfs2: get rid of private conversion macros on bmap key and pointer

Will remove nilfs_bmap_key_to_dkey(), nilfs_bmap_dkey_to_key(),
nilfs_bmap_ptr_to_dptr(), and nilfs_bmap_dptr_to_ptr() for simplicity.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

nilfs2: trivial coding style fix

This is a trivial style fix patch to mend errors/warnings
reported by "checkpatch.pl --file".

Signed-off-by: Jiro SEKIBA <jir@unicus.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

nilfs2: allow btree code to directly call dat operations

The current btree code is written so that btree functions call dat
operations via wrapper functions in bmap.c when they allocate, free,
or modify virtual block addresses.

This abstraction requires additional function calls and causes
frequent call of nilfs_bmap_get_dat() function since it is used in the
every wrapper function.

This removes the wrapper functions and makes them available from
btree.c and direct.c, which will increase the opportunity of
compiler optimization.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

nilfs2: support contiguous lookup of blocks

Although get_block() callback function can return extent of contiguous
blocks with bh->b_size, nilfs_get_block() function did not support
this feature.

This adds contiguous lookup feature to the block mapping codes of
nilfs, and allows the nilfs_get_blocks() function to return the extent
information by applying the feature.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

nilfs2: remove nilfs_direct_operations from direct mapping

will remove indirect function calls using nilfs_direct_operations
table.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

nilfs2: remove bmap pointer operations

Previously, the bmap codes of nilfs used three types of function
tables. The abuse of indirect function calls decreased source
readability and suffered many indirect jumps which would confuse
branch prediction of processors.

This eliminates one type of the function tables,
nilfs_bmap_ptr_operations, which was used to dispatch low level
pointer operations of the nilfs bmap.

This adds a new integer variable "b_ptr_type" to nilfs_bmap struct,
and uses the value to select the pointer operations.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

nilfs2: remove useless b_low and b_high fields from nilfs_bmap struct

This will cut off 16 bytes from the nilfs_bmap struct which is
embedded in the on-memory inode of nilfs.

The b_high field was never used, and the b_low field stores a constant
value which can be determined by whether the inode uses btree for
block mapping or not.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

nilfs2: remove pointless NULL check of bpop_commit_alloc_ptr function

This indirect function is set to NULL only for gc cache inodes, but
the gc cache inodes never call this function.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

nilfs2: unify bmap operations starting use of indirect block address

This simplifies some low level functions of bmap.

Three bmap pointer operations, nilfs_bmap_start_v(),
nilfs_bmap_commit_v(), and nilfs_bmap_abort_v(), are unified into one
nilfs_bmap_start_v() function. And the related indirect function calls
are replaced with it.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

nilfs2: replace BUG_ON and BUG calls triggerable from ioctl

Pekka Enberg advised me:
> It would be nice if BUG(), BUG_ON(), and panic() calls would be
> converted to proper error handling using WARN_ON() calls. The BUG()
> call in nilfs_cpfile_delete_checkpoints(), for example, looks to be
> triggerable from user-space via the ioctl() system call.

This will follow the comment and keep them to a minimum.

Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: clean up indirect function calling conventions

This cleans up the strange indirect function calling convention used in
nilfs to follow the normal kernel coding style.

Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: direct block mapping

This adds block mappings using direct pointers which are stored in the
i_bmap array of inode.

Signed-off-by: Koji Sato <sato.koji@lab.ntt.co.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>