From: Martijn Coenen <maco@android.com>
To: axboe@kernel.dk, hch@lst.de, ming.lei@redhat.com
Cc: narayan@google.com, zezeozue@google.com, kernel-team@android.com,
maco@google.com, bvanassche@acm.org, Chaitanya.Kulkarni@wdc.com,
jaegeuk@kernel.org, linux-block@vger.kernel.org,
linux-kernel@vger.kernel.org, Martijn Coenen <maco@android.com>
Subject: [PATCH v4 04/10] loop: Refactor loop_set_status() size calculation
Date: Wed, 29 Apr 2020 16:03:35 +0200 [thread overview]
Message-ID: <20200429140341.13294-5-maco@android.com> (raw)
In-Reply-To: <20200429140341.13294-1-maco@android.com>
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@android.com>
---
drivers/block/loop.c | 44 +++++++++++++++++++++++---------------------
1 file changed, 23 insertions(+), 21 deletions(-)
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 8f3194c2b8aa..9f5913879921 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -268,11 +268,6 @@ figure_loop_size(struct loop_device *lo, loff_t offset, loff_t sizelimit)
if (err)
return err;
- if (lo->lo_offset != offset)
- lo->lo_offset = offset;
- if (lo->lo_sizelimit != sizelimit)
- lo->lo_sizelimit = sizelimit;
-
loop_set_size(lo, size);
return 0;
@@ -1294,6 +1289,8 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
kuid_t uid = current_uid();
struct block_device *bdev;
bool partscan = false;
+ bool size_changed = false;
+ loff_t validated_size;
err = mutex_lock_killable(&loop_ctl_mutex);
if (err)
@@ -1315,6 +1312,13 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
if (lo->lo_offset != info->lo_offset ||
lo->lo_sizelimit != info->lo_sizelimit) {
+ loff_t size = get_size(info->lo_offset, info->lo_sizelimit,
+ lo->lo_backing_file);
+ err = loop_validate_size(size);
+ if (err)
+ goto out_unlock;
+ size_changed = true;
+ validated_size = size;
sync_blockdev(lo->lo_device);
kill_bdev(lo->lo_device);
}
@@ -1322,6 +1326,15 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
/* 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 kill_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;
@@ -1345,22 +1358,8 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
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;
- }
- if (figure_loop_size(lo, info->lo_offset, info->lo_sizelimit)) {
- err = -EFBIG;
- goto out_unfreeze;
- }
- }
-
+ 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;
@@ -1384,6 +1383,9 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
lo->lo_key_owner = uid;
}
+ if (size_changed)
+ loop_set_size(lo, validated_size);
+
loop_config_discard(lo);
/* update dio if lo_offset or transfer is changed */
--
2.26.2.303.gf8c07b1a785-goog
next prev parent reply other threads:[~2020-04-29 14:03 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-29 14:03 [PATCH v4 00/10] Add a new LOOP_CONFIGURE ioctl Martijn Coenen
2020-04-29 14:03 ` [PATCH v4 01/10] loop: Factor out loop size validation Martijn Coenen
2020-04-29 14:12 ` Ming Lei
2020-05-01 11:33 ` Martijn Coenen
2020-05-01 17:26 ` Christoph Hellwig
2020-04-29 14:03 ` [PATCH v4 02/10] loop: Factor out setting loop device size Martijn Coenen
2020-05-01 17:26 ` Christoph Hellwig
2020-04-29 14:03 ` [PATCH v4 03/10] loop: Switch to set_capacity_revalidate_and_notify() Martijn Coenen
2020-05-01 17:27 ` Christoph Hellwig
2020-04-29 14:03 ` Martijn Coenen [this message]
2020-05-01 17:30 ` [PATCH v4 04/10] loop: Refactor loop_set_status() size calculation Christoph Hellwig
2020-05-01 19:33 ` Martijn Coenen
2020-05-06 5:10 ` Christoph Hellwig
2020-05-06 6:03 ` Christoph Hellwig
2020-04-29 14:03 ` [PATCH v4 05/10] loop: Remove figure_loop_size() Martijn Coenen
2020-05-06 6:04 ` Christoph Hellwig
2020-04-29 14:03 ` [PATCH v4 06/10] loop: Factor out configuring loop from status Martijn Coenen
2020-05-06 6:05 ` Christoph Hellwig
2020-04-29 14:03 ` [PATCH v4 07/10] loop: Move loop_set_status_from_info() and friends up Martijn Coenen
2020-05-06 6:06 ` Christoph Hellwig
2020-04-29 14:03 ` [PATCH v4 08/10] loop: Rework lo_ioctl() __user argument casting Martijn Coenen
2020-05-06 6:07 ` Christoph Hellwig
2020-04-29 14:03 ` [PATCH v4 09/10] loop: Clean up LOOP_SET_STATUS lo_flags handling Martijn Coenen
2020-05-06 6:08 ` Christoph Hellwig
2020-04-29 14:03 ` [PATCH v4 10/10] loop: Add LOOP_CONFIGURE ioctl Martijn Coenen
2020-05-06 6:09 ` Christoph Hellwig
2020-05-06 9:55 ` Martijn Coenen
2020-05-06 9:44 ` Michael Kerrisk (man-pages)
2020-05-06 9:57 ` Martijn Coenen
2020-05-12 6:46 ` Martijn Coenen
2020-05-13 2:29 ` Jens Axboe
2020-05-13 2:30 ` Jens Axboe
2020-05-13 7:07 ` Martijn Coenen
2020-05-13 10:22 ` Christoph Hellwig
2020-05-13 13:49 ` Martijn Coenen
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