Calling capable() to determine if we can bypass quota enforcement or not
can trigger spurious audit messages. We don't really require it here so
just use the capable_noaudit() version.

Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

CONFIG_PRINT_QUOTA_WARNING was marked as BROKEN in 2023 by 36d532d713db
("quota: mark PRINT_QUOTA_WARNING as BROKEN").

The code is apparently unused and uninteresting, so remove it all, incl.
the abuse of TTY.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jan Kara <jack@suse.com>
Cc: Yangtao Li <frank.li@vivo.com>
Link: https://patch.msgid.link/20260722060155.1111519-1-jirislaby@kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>

dquot_init() allocates a single page for dquot_hash with
__get_free_pages().

kmalloc() is a better API for such use and it also provides better
scalability and more debugging possibilities.

Replace use of __get_free_pages() with kmalloc() and get rid of the order
variable that remained 0 for more than 20 years.

Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Link: https://patch.msgid.link/20260523-b4-fs-v1-1-275e36a83f0e@kernel.org
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>

dquot_scan_active() can race with quota deactivation in
quota_release_workfn() like:

  CPU0 (quota_release_workfn)         CPU1 (dquot_scan_active)
  ==============================      ==============================
  spin_lock(&dq_list_lock);
  list_replace_init(
    &releasing_dquots, &rls_head);
    /* dquot X on rls_head,
       dq_count == 0,
       DQ_ACTIVE_B still set */
  spin_unlock(&dq_list_lock);
  synchronize_srcu(&dquot_srcu);
                                      spin_lock(&dq_list_lock);
                                      list_for_each_entry(dquot,
                                          &inuse_list, dq_inuse) {
                                        /* finds dquot X */
                                        dquot_active(X) -> true
                                        atomic_inc(&X->dq_count);
                                      }
                                      spin_unlock(&dq_list_lock);
  spin_lock(&dq_list_lock);
  dquot = list_first_entry(&rls_head);
  WARN_ON_ONCE(atomic_read(&dquot->dq_count));

The problem is not only a cosmetic one as under memory pressure the
caller of dquot_scan_active() can end up working on freed dquot.

Fix the problem by making sure the dquot is removed from releasing list
when we acquire a reference to it.

Fixes: 869b6ea1609f ("quota: Fix slow quotaoff")
Reported-by: Sam Sun <samsun1006219@gmail.com>
Link: https://lore.kernel.org/all/CAEkJfYPTt3uP1vAYnQ5V2ZWn5O9PLhhGi5HbOcAzyP9vbXyjeg@mail.gmail.com
Signed-off-by: Jan Kara <jack@suse.cz>

This was done entirely with mindless brute force, using

    git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
        xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'

to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.

Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.

For the same reason the 'flex' versions will be done as a separate
conversion.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook <kees@kernel.org>

Pull quota and isofs updates from Jan Kara:

 - a fix for quotactl livelock during filesystem freezing

 - a small improvement for isofs

 - a documentation fix for ext2

* tag 'fs_for_v6.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  isofs: support full length file names (255 instead of 253)
  quota: fix livelock between quotactl and freeze_super
  doc : fix a broken link in ext2.rst

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

When a filesystem is frozen, quotactl_block() enters a retry loop
waiting for the filesystem to thaw. It acquires s_umount, checks the
freeze state, drops s_umount and uses sb_start_write() - sb_end_write()
pair to wait for the unfreeze.

However, this retry loop can trigger a livelock issue, specifically on
kernels with preemption disabled.

The mechanism is as follows:
1. freeze_super() sets SB_FREEZE_WRITE and calls sb_wait_write().
2. sb_wait_write() calls percpu_down_write(), which initiates
   synchronize_rcu().
3. Simultaneously, quotactl_block() spins in its retry loop, immediately
   executing the sb_start_write() - sb_end_write() pair.
4. Because the kernel is non-preemptible and the loop contains no
   scheduling points, quotactl_block() never yields the CPU. This
   prevents that CPU from reaching an RCU quiescent state.
5. synchronize_rcu() in the freezer thread waits indefinitely for the
   quotactl_block() CPU to report a quiescent state.
6. quotactl_block() spins indefinitely waiting for the freezer to
   advance, which it cannot do as it is blocked on the RCU sync.

This results in a hang of the freezer process and 100% CPU usage by the
quota process.

While this can occur intermittently on multi-core systems, it is
reliably reproducing on a node with the following script, running both
the freezer and the quota toggle on the same CPU:

  # mkfs.ext4 -O quota /dev/sda 2g && mkdir a_mount
  # mount /dev/sda -o quota,usrquota,grpquota a_mount
  # taskset -c 3 bash -c "while true; do xfs_freeze -f a_mount; \
    xfs_freeze -u a_mount; done" &
  # taskset -c 3 bash -c "while true; do quotaon a_mount; \
    quotaoff a_mount; done" &

Adding cond_resched() to the retry loop fixes the issue. It acts as an
RCU quiescent state, allowing synchronize_rcu() in percpu_down_write()
to complete.

Fixes: 576215cffdef ("fs: Drop wait_unfrozen wait queue")
Signed-off-by: Abhishek Bapat <abhishekbapat@google.com>
Link: https://patch.msgid.link/20260115213103.1089129-1-abhishekbapat@google.com
Signed-off-by: Jan Kara <jack@suse.cz>

All places were patched by coccinelle with the default expecting that
->i_lock is held, afterwards entries got fixed up by hand to use
unlocked variants as needed.

The script:
@@
expression inode, flags;
@@

- inode->i_state & flags
+ inode_state_read(inode) & flags

@@
expression inode, flags;
@@

- inode->i_state &= ~flags
+ inode_state_clear(inode, flags)

@@
expression inode, flag1, flag2;
@@

- inode->i_state &= ~flag1 & ~flag2
+ inode_state_clear(inode, flag1 | flag2)

@@
expression inode, flags;
@@

- inode->i_state |= flags
+ inode_state_set(inode, flags)

@@
expression inode, flags;
@@

- inode->i_state = flags
+ inode_state_assign(inode, flags)

@@
expression inode, flags;
@@

- flags = inode->i_state
+ flags = inode_state_read(inode)

@@
expression inode, flags;
@@

- READ_ONCE(inode->i_state) & flags
+ inode_state_read(inode) & flags

Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>