To prevent inodes with invalid file types from tripping through the vfs
and causing malfunctions or assertion failures, add a missing sanity check
when reading an inode from a block device.  If the file type is not valid,
treat it as a filesystem error.

Link: https://lkml.kernel.org/r/20250710134952.29862-1-konishi.ryusuke@gmail.com
Fixes: 05fe58fdc10d ("nilfs2: inode operations")
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+895c23f6917da440ed0d@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?extid=895c23f6917da440ed0d
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Move this API to the canonical timer_*() namespace.

[ tglx: Redone against pre rc1 ]

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/aB2X0jCKQO56WdMt@gmail.com

Since commit 013a07052a1a ("nilfs2: convert metadata aops from writepage
to writepages"), nilfs_mdt_write_folio can't be called from reclaim
context any more.  Remove the code keyed of the wbc->for_reclaim flag,
which is now only set for writing out swap or shmem pages inside the swap
code, but never passed to file systems.

Link: https://lkml.kernel.org/r/20250508054938.15894-7-hch@lst.de
Link: https://lkml.kernel.org/r/20250516123417.6779-1-konishi.ryusuke@gmail.com
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

In preparation for writing logs, in nilfs_btree_propagate(), which makes
parent and ancestor node blocks dirty starting from a modified data block
or b-tree node block, if the starting block does not belong to the b-tree,
i.e.  is isolated, nilfs_btree_do_lookup() called within the function
fails with -ENOENT.

In this case, even though -ENOENT is an internal code, it is propagated to
the log writer via nilfs_bmap_propagate() and may be erroneously returned
to system calls such as fsync().

Fix this issue by changing the error code to -EINVAL in this case, and
having the bmap layer detect metadata corruption and convert the error
code appropriately.

Link: https://lkml.kernel.org/r/20250428173808.6452-3-konishi.ryusuke@gmail.com
Fixes: 1f5abe7e7dbc ("nilfs2: replace BUG_ON and BUG calls triggerable from ioctl")
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Wentao Liang <vulab@iscas.ac.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Patch series "nilfs2: improve sanity checks in dirty state propagation".

This fixes one missed check for block mapping anomalies and one improper
return of an error code during a preparation step for log writing, thereby
improving checking for filesystem corruption on writeback.


This patch (of 2):

In nilfs_direct_propagate(), the printer get from nilfs_direct_get_ptr()
need to be checked to ensure it is not an invalid pointer.

If the pointer value obtained by nilfs_direct_get_ptr() is
NILFS_BMAP_INVALID_PTR, means that the metadata (in this case, i_bmap in
the nilfs_inode_info struct) that should point to the data block at the
buffer head of the argument is corrupted and the data block is orphaned,
meaning that the file system has lost consistency.

Add a value check and return -EINVAL when it is an invalid pointer.

Link: https://lkml.kernel.org/r/20250428173808.6452-1-konishi.ryusuke@gmail.com
Link: https://lkml.kernel.org/r/20250428173808.6452-2-konishi.ryusuke@gmail.com
Fixes: 36a580eb489f ("nilfs2: direct block mapping")
Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

After commit c0e473a0d226 ("block: fix race between set_blocksize and read
paths") was merged, set_blocksize() called by sb_set_blocksize() now locks
the inode of the backing device file.  As a result of this change, syzbot
started reporting deadlock warnings due to a circular dependency involving
the semaphore "ns_sem" of the nilfs object, the inode lock of the backing
device file, and the locks that this inode lock is transitively dependent
on.

This is caused by a new lock dependency added by the above change, since
init_nilfs() calls sb_set_blocksize() in the lock section of "ns_sem". 
However, these warnings are false positives because init_nilfs() is called
in the early stage of the mount operation and the filesystem has not yet
started.

The reason why "ns_sem" is locked in init_nilfs() was to avoid a race
condition in nilfs_fill_super() caused by sharing a nilfs object among
multiple filesystem instances (super block structures) in the early
implementation.  However, nilfs objects and super block structures have
long ago become one-to-one, and there is no longer any need to use the
semaphore there.

So, fix this issue by removing the use of the semaphore "ns_sem" in
init_nilfs().

Link: https://lkml.kernel.org/r/20250503053327.12294-1-konishi.ryusuke@gmail.com
Fixes: c0e473a0d226 ("block: fix race between set_blocksize and read paths")
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+00f7f5b884b117ee6773@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=00f7f5b884b117ee6773
Tested-by: syzbot+00f7f5b884b117ee6773@syzkaller.appspotmail.com
Reported-by: syzbot+f30591e72bfc24d4715b@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=f30591e72bfc24d4715b
Tested-by: syzbot+f30591e72bfc24d4715b@syzkaller.appspotmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree
over and remove the historical wrapper inlines.

Conversion was done with coccinelle plus manual fixups where necessary.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Some filesystems, such as NFS, cifs, ceph, and fuse, do not have
complete control of sequencing on the actual filesystem (e.g.  on a
different server) and may find that the inode created for a mkdir
request already exists in the icache and dcache by the time the mkdir
request returns.  For example, if the filesystem is mounted twice the
directory could be visible on the other mount before it is on the
original mount, and a pair of name_to_handle_at(), open_by_handle_at()
calls could instantiate the directory inode with an IS_ROOT() dentry
before the first mkdir returns.

This means that the dentry passed to ->mkdir() may not be the one that
is associated with the inode after the ->mkdir() completes.  Some
callers need to interact with the inode after the ->mkdir completes and
they currently need to perform a lookup in the (rare) case that the
dentry is no longer hashed.

This lookup-after-mkdir requires that the directory remains locked to
avoid races.  Planned future patches to lock the dentry rather than the
directory will mean that this lookup cannot be performed atomically with
the mkdir.

To remove this barrier, this patch changes ->mkdir to return the
resulting dentry if it is different from the one passed in.
Possible returns are:
  NULL - the directory was created and no other dentry was used
  ERR_PTR() - an error occurred
  non-NULL - this other dentry was spliced in

This patch only changes file-systems to return "ERR_PTR(err)" instead of
"err" or equivalent transformations.  Subsequent patches will make
further changes to some file-systems to return a correct dentry.

Not all filesystems reliably result in a positive hashed dentry:

- NFS, cifs, hostfs will sometimes need to perform a lookup of
  the name to get inode information.  Races could result in this
  returning something different. Note that this lookup is
  non-atomic which is what we are trying to avoid.  Placing the
  lookup in filesystem code means it only happens when the filesystem
  has no other option.
- kernfs and tracefs leave the dentry negative and the ->revalidate
  operation ensures that lookup will be called to correctly populate
  the dentry.  This could be fixed but I don't think it is important
  to any of the users of vfs_mkdir() which look at the dentry.

The recommendation to use
    d_drop();d_splice_alias()
is ugly but fits with current practice.  A planned future patch will
change this.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: NeilBrown <neilb@suse.de>
Link: https://lore.kernel.org/r/20250227013949.536172-2-neilb@suse.de
Signed-off-by: Christian Brauner <brauner@kernel.org>

Since nilfs_bmap_lookup_contig() in nilfs_fiemap() calculates its result
by being prepared to go through potentially maxblocks == INT_MAX blocks,
the value in n may experience an overflow caused by left shift of blkbits.

While it is extremely unlikely to occur, play it safe and cast right hand
expression to wider type to mitigate the issue.

Found by Linux Verification Center (linuxtesting.org) with static analysis
tool SVACE.

Link: https://lkml.kernel.org/r/20250124222133.5323-1-konishi.ryusuke@gmail.com
Fixes: 622daaff0a89 ("nilfs2: fiemap support")
Signed-off-by: Nikita Zhandarovich <n.zhandarovich@fintech.ru>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

A minor issue with nilfs_rename, originating from an old ext2
implementation, is that the mtime is updated even if the rename target is
a directory and it is renamed within the same directory, rather than moved
to a different directory.

In this case, the child directory being renamed does not change in any
way, so changing its mtime is unnecessary according to the specification,
and can unnecessarily confuse backup tools.

In ext2, this issue was fixed by commit 39fe7557b4d6 ("ext2: Do not update
mtime of a moved directory") and a few subsequent fixes, but it remained
in nilfs2.

Fix this issue by not calling nilfs_set_link(), which rewrites the inode
number of the directory entry that refers to the parent directory, when
the move target is a directory and the source and destination are the same
directory.

Here, the directory to be moved only needs to be read if the inode number
of the parent directory is rewritten with nilfs_set_link, so also adjust
the execution conditions of the preparation work to avoid unnecessary
directory reads.

Link: https://lkml.kernel.org/r/20250111143518.7901-3-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>