This is a note to let you know that I've just added the patch titled
loop: Refactor loop_set_status() size calculation
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
loop-refactor-loop_set_status-size-calculation.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From stable+bounces-25714-greg=kroah.com@xxxxxxxxxxxxxxx Fri Mar 1 02:33:57 2024
From: Genjian <zhanggenjian@xxxxxxx>
Date: Fri, 1 Mar 2024 09:30:24 +0800
Subject: loop: Refactor loop_set_status() size calculation
To: stable@xxxxxxxxxxxxxxx
Cc: axboe@xxxxxxxxx, stable@xxxxxxxxxx, linux-block@xxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx, zhanggenjian123@xxxxxxxxx, Martijn Coenen <maco@xxxxxxxxxxx>, Christoph Hellwig <hch@xxxxxx>, Genjian Zhang <zhanggenjian@xxxxxxxxxx>
Message-ID: <20240301013028.2293831-6-zhanggenjian@xxxxxxx>
From: Martijn Coenen <maco@xxxxxxxxxxx>
[ Upstream commit b0bd158dd630bd47640e0e418c062cda1e0da5ad ]
figure_loop_size() calculates the loop size based on the passed in
parameters, but at the same time it updates the offset and sizelimit
parameters in the loop device configuration. That is a somewhat
unexpected side effect of a function with this name, and it is only only
needed by one of the two callers of this function - loop_set_status().
Move the lo_offset and lo_sizelimit assignment back into loop_set_status(),
and use the newly factored out functions to validate and apply the newly
calculated size. This allows us to get rid of figure_loop_size() in a
follow-up commit.
Signed-off-by: Martijn Coenen <maco@xxxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Genjian Zhang <zhanggenjian@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/block/loop.c | 37 +++++++++++++++++++------------------
1 file changed, 19 insertions(+), 18 deletions(-)
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -248,11 +248,6 @@ figure_loop_size(struct loop_device *lo,
{
loff_t size = get_size(offset, sizelimit, lo->lo_backing_file);
- if (lo->lo_offset != offset)
- lo->lo_offset = offset;
- if (lo->lo_sizelimit != sizelimit)
- lo->lo_sizelimit = sizelimit;
-
loop_set_size(lo, size);
}
@@ -1225,6 +1220,7 @@ loop_set_status(struct loop_device *lo,
kuid_t uid = current_uid();
struct block_device *bdev;
bool partscan = false;
+ bool size_changed = false;
err = mutex_lock_killable(&loop_ctl_mutex);
if (err)
@@ -1246,6 +1242,7 @@ loop_set_status(struct loop_device *lo,
if (lo->lo_offset != info->lo_offset ||
lo->lo_sizelimit != info->lo_sizelimit) {
+ size_changed = true;
sync_blockdev(lo->lo_device);
invalidate_bdev(lo->lo_device);
}
@@ -1253,6 +1250,15 @@ loop_set_status(struct loop_device *lo,
/* I/O need to be drained during transfer transition */
blk_mq_freeze_queue(lo->lo_queue);
+ if (size_changed && lo->lo_device->bd_inode->i_mapping->nrpages) {
+ /* If any pages were dirtied after invalidate_bdev(), try again */
+ err = -EAGAIN;
+ pr_warn("%s: loop%d (%s) has still dirty pages (nrpages=%lu)\n",
+ __func__, lo->lo_number, lo->lo_file_name,
+ lo->lo_device->bd_inode->i_mapping->nrpages);
+ goto out_unfreeze;
+ }
+
err = loop_release_xfer(lo);
if (err)
goto out_unfreeze;
@@ -1276,19 +1282,8 @@ loop_set_status(struct loop_device *lo,
if (err)
goto out_unfreeze;
- if (lo->lo_offset != info->lo_offset ||
- lo->lo_sizelimit != info->lo_sizelimit) {
- /* kill_bdev should have truncated all the pages */
- if (lo->lo_device->bd_inode->i_mapping->nrpages) {
- err = -EAGAIN;
- pr_warn("%s: loop%d (%s) has still dirty pages (nrpages=%lu)\n",
- __func__, lo->lo_number, lo->lo_file_name,
- lo->lo_device->bd_inode->i_mapping->nrpages);
- goto out_unfreeze;
- }
- figure_loop_size(lo, info->lo_offset, info->lo_sizelimit);
- }
-
+ lo->lo_offset = info->lo_offset;
+ lo->lo_sizelimit = info->lo_sizelimit;
memcpy(lo->lo_file_name, info->lo_file_name, LO_NAME_SIZE);
memcpy(lo->lo_crypt_name, info->lo_crypt_name, LO_NAME_SIZE);
lo->lo_file_name[LO_NAME_SIZE-1] = 0;
@@ -1312,6 +1307,12 @@ loop_set_status(struct loop_device *lo,
lo->lo_key_owner = uid;
}
+ if (size_changed) {
+ loff_t new_size = get_size(lo->lo_offset, lo->lo_sizelimit,
+ lo->lo_backing_file);
+ loop_set_size(lo, new_size);
+ }
+
loop_config_discard(lo);
/* update dio if lo_offset or transfer is changed */
Patches currently in stable-queue which might be from kroah.com@xxxxxxxxxxxxxxx are
queue-4.19/loop-factor-out-configuring-loop-from-status.patch
queue-4.19/loop-call-loop_config_discard-only-after-new-config-is-applied.patch
queue-4.19/loop-refactor-loop_set_status-size-calculation.patch
queue-4.19/loop-factor-out-setting-loop-device-size.patch
queue-4.19/loop-check-for-overflow-while-configuring-loop.patch
queue-4.19/loop-properly-observe-rotational-flag-of-underlying-device.patch
queue-4.19/loop-remove-sector_t-truncation-checks.patch
queue-4.19/revert-loop-check-for-overflow-while-configuring-loop.patch
queue-4.19/loop-loop_set_status_from_info-check-before-assignment.patch
