linux-toradex.git/drivers/block/loop.c, branch v6.16-rc5

loop: move lo_set_size() out of queue freeze

2025-06-11T12:41:45+00:00

It isn't necessary to freeze queue for updating disk size given submit_bio()
doesn't grab queue usage counter for checking eod.

Also many driver won't freeze queue for calling set_capacity_and_notify().

Move lo_set_size() out of queue freeze for fixing many lockdep warning
report.

Link: https://lore.kernel.org/linux-block/67ea99e0.050a0220.3c3d88.0042.GAE@google.com/
Reported-by: syzbot+9dd7dbb1a4b915dee638@syzkaller.appspotmail.com
Signed-off-by: Ming Lei 
Link: https://lore.kernel.org/r/20250611084938.108829-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe

loop: add file_start_write() and file_end_write()

2025-05-27T16:14:26+00:00

file_start_write() and file_end_write() should be added around ->write_iter().

Recently we switch to ->write_iter() from vfs_iter_write(), and the
implied file_start_write() and file_end_write() are lost.

Also we never add them for dio code path, so add them back for covering
both.

Cc: Jeff Moyer 
Fixes: f2fed441c69b ("loop: stop using vfs_iter_{read,write} for buffered I/O")
Fixes: bc07c10a3603 ("block: loop: support DIO & AIO")
Signed-off-by: Ming Lei 
Link: https://lore.kernel.org/r/20250527153405.837216-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe

loop: don't require ->write_iter for writable files in loop_configure

2025-05-20T15:16:23+00:00

Block devices can be opened read-write even if they can't be written to
for historic reasons.  Remove the check requiring file->f_op->write_iter
when the block devices was opened in loop_configure. The call to
loop_check_backing_file just below ensures the ->write_iter is present
for backing files opened for writing, which is the only check that is
actually needed.

Fixes: f5c84eff634b ("loop: Add sanity check for read/write_iter")
Reported-by: Christian Hesse 
Signed-off-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20250520135420.1177312-1-hch@lst.de
Signed-off-by: Jens Axboe

loop: Add sanity check for read/write_iter

2025-05-05T13:18:05+00:00

Some file systems do not support read_iter/write_iter, such as selinuxfs
in this issue.
So before calling them, first confirm that the interface is supported and
then call it.

It is releavant in that vfs_iter_read/write have the check, and removal
of their used caused szybot to be able to hit this issue.

Fixes: f2fed441c69b ("loop: stop using vfs_iter__{read,write} for buffered I/O")
Reported-by: syzbot+6af973a3b8dfd2faefdc@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=6af973a3b8dfd2faefdc
Signed-off-by: Lizhi Xu 
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20250428143626.3318717-1-lizhi.xu@windriver.com
Signed-off-by: Jens Axboe

loop: stop using vfs_iter_{read,write} for buffered I/O

2025-04-16T00:59:15+00:00

vfs_iter_{read,write} always perform direct I/O when the file has the
O_DIRECT flag set, which breaks disabling direct I/O using the
LOOP_SET_STATUS / LOOP_SET_STATUS64 ioctls.

This was recenly reported as a regression, but as far as I can tell
was only uncovered by better checking for block sizes and has been
around since the direct I/O support was added.

Fix this by using the existing aio code that calls the raw read/write
iter methods instead.  Note that despite the comments there is no need
for block drivers to ever call flush_dcache_page themselves, and the
call is a left-over from prehistoric times.

Fixes: ab1cb278bc70 ("block: loop: introduce ioctl command of LOOP_SET_DIRECT_IO")
Reported-by: Darrick J. Wong 
Signed-off-by: Christoph Hellwig 
Reviewed-by: Ming Lei 
Tested-by: Darrick J. Wong 
Link: https://lore.kernel.org/r/20250409130940.3685677-1-hch@lst.de
Signed-off-by: Jens Axboe

loop: LOOP_SET_FD: send uevents for partitions

2025-04-15T19:15:21+00:00

Remove the suppression of the uevents before scanning for partitions.
The partitions inherit their suppression settings from their parent device,
which lead to the uevents being dropped.

This is similar to the same changes for LOOP_CONFIGURE done in
commit bb430b694226 ("loop: LOOP_CONFIGURE: send uevents for partitions").

Fixes: 498ef5c777d9 ("loop: suppress uevents while reconfiguring the device")
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Weißschuh 
Reviewed-by: Jan Kara 
Link: https://lore.kernel.org/r/20250415-loop-uevent-changed-v3-1-60ff69ac6088@linutronix.de
Signed-off-by: Jens Axboe

loop: properly send KOBJ_CHANGED uevent for disk device

2025-04-15T14:58:42+00:00

The original commit message and the wording "uncork" in the code comment
indicate that it is expected that the suppressed event instances are
automatically sent after unsuppressing.
This is not the case, instead they are discarded.
In effect this means that no "changed" events are emitted on the device
itself by default.
While each discovered partition does trigger a changed event on the
device, devices without partitions don't have any event emitted.

This makes udev miss the device creation and prompted workarounds in
userspace. See the linked util-linux/losetup bug.

Explicitly emit the events and drop the confusingly worded comments.

Link: https://github.com/util-linux/util-linux/issues/2434
Fixes: 498ef5c777d9 ("loop: suppress uevents while reconfiguring the device")
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Weißschuh 
Link: https://lore.kernel.org/r/20250415-loop-uevent-changed-v2-1-0c4e6a923b2a@linutronix.de
Signed-off-by: Jens Axboe

loop: aio inherit the ioprio of original request

2025-04-15T14:58:38+00:00

Set cmd->iocb.ki_ioprio to the ioprio of loop device's request.
The purpose is to inherit the original request ioprio in the aio
flow.

Signed-off-by: Yunlong Xing 
Signed-off-by: Zhiguo Niu 
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20250414030159.501180-1-yunlong.xing@unisoc.com
Signed-off-by: Jens Axboe

loop: move vfs_fsync() out of loop_update_dio()

2025-03-18T14:03:30+00:00

If vfs_flush() is called with queue frozen, the queue freeze lock may be
connected with FS internal lock, and lockdep warning can be triggered
because the queue freeze lock is connected with too many global or
sub-system locks.

Fix the warning by moving vfs_fsync() out of loop_update_dio():

- vfs_fsync() is only needed when switching to dio

- only loop_change_fd() and loop_configure() may switch from buffered
IO to direct IO, so call vfs_fsync() directly here. This way is safe
because either loop is in unbound, or new file isn't attached

- for the other two cases of set_status and set_block_size, direct IO
can only become off, so no need to call vfs_fsync()

Cc: Christoph Hellwig 
Reported-by: Kun Hu 
Reported-by: Jiaji Qin 
Closes: https://lore.kernel.org/linux-block/359BC288-B0B1-4815-9F01-3A349B12E816@m.fudan.edu.cn/T/#u
Signed-off-by: Ming Lei 
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20250318072955.3893805-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe

loop: Remove struct loop_func_table

2025-03-04T14:14:47+00:00

The struct is introduced in the commit 754d96798fab
("loop: remove loop.h"), but it is not used now.
So remove it.

No functional changes.

Signed-off-by: Zhu Yanjun 
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20250227163343.55952-1-yanjun.zhu@linux.dev
Signed-off-by: Jens Axboe