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 09/10] loop: Clean up LOOP_SET_STATUS lo_flags handling.
Date: Wed, 29 Apr 2020 16:03:40 +0200 [thread overview]
Message-ID: <20200429140341.13294-10-maco@android.com> (raw)
In-Reply-To: <20200429140341.13294-1-maco@android.com>
LOOP_SET_STATUS(64) will actually allow some lo_flags to be modified; in
particular, LO_FLAGS_AUTOCLEAR can be set and cleared, whereas
LO_FLAGS_PARTSCAN can be set to request a partition scan. Make this
explicit by updating the UAPI to include the flags that can be
set/cleared using this ioctl.
The implementation can then blindly take over the passed in flags,
and use the previous flags for those flags that can't be set / cleared
using LOOP_SET_STATUS.
Signed-off-by: Martijn Coenen <maco@android.com>
---
drivers/block/loop.c | 19 +++++++++++++------
include/uapi/linux/loop.h | 10 ++++++++--
2 files changed, 21 insertions(+), 8 deletions(-)
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index f172a64333aa..cfbdd99fdb1a 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1049,9 +1049,7 @@ loop_set_status_from_info(struct loop_device *lo,
lo->transfer = xfer->transfer;
lo->ioctl = xfer->ioctl;
- if ((lo->lo_flags & LO_FLAGS_AUTOCLEAR) !=
- (info->lo_flags & LO_FLAGS_AUTOCLEAR))
- lo->lo_flags ^= LO_FLAGS_AUTOCLEAR;
+ lo->lo_flags = info->lo_flags;
lo->lo_encrypt_key_size = info->lo_encrypt_key_size;
lo->lo_init[0] = info->lo_init[0];
@@ -1338,6 +1336,7 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
int err;
struct block_device *bdev;
kuid_t uid = current_uid();
+ int prev_lo_flags;
bool partscan = false;
bool size_changed = false;
loff_t validated_size;
@@ -1381,10 +1380,19 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
goto out_unfreeze;
}
+ prev_lo_flags = lo->lo_flags;
+
err = loop_set_status_from_info(lo, info);
if (err)
goto out_unfreeze;
+ /* Mask out flags that can't be set using LOOP_SET_STATUS. */
+ lo->lo_flags &= ~LOOP_SET_STATUS_SETTABLE_FLAGS;
+ /* For those flags, use the previous values instead */
+ lo->lo_flags |= prev_lo_flags & ~LOOP_SET_STATUS_SETTABLE_FLAGS;
+ /* For flags that can't be cleared, use previous values too */
+ lo->lo_flags |= prev_lo_flags & ~LOOP_SET_STATUS_CLEARABLE_FLAGS;
+
if (size_changed)
loop_set_size(lo, validated_size);
@@ -1396,9 +1404,8 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
out_unfreeze:
blk_mq_unfreeze_queue(lo->lo_queue);
- if (!err && (info->lo_flags & LO_FLAGS_PARTSCAN) &&
- !(lo->lo_flags & LO_FLAGS_PARTSCAN)) {
- lo->lo_flags |= LO_FLAGS_PARTSCAN;
+ if (!err && (lo->lo_flags & LO_FLAGS_PARTSCAN) &&
+ !(prev_lo_flags & LO_FLAGS_PARTSCAN)) {
lo->lo_disk->flags &= ~GENHD_FL_NO_PART_SCAN;
bdev = lo->lo_device;
partscan = true;
diff --git a/include/uapi/linux/loop.h b/include/uapi/linux/loop.h
index 080a8df134ef..6b32fee80ce0 100644
--- a/include/uapi/linux/loop.h
+++ b/include/uapi/linux/loop.h
@@ -25,6 +25,12 @@ enum {
LO_FLAGS_DIRECT_IO = 16,
};
+/* LO_FLAGS that can be set using LOOP_SET_STATUS(64) */
+#define LOOP_SET_STATUS_SETTABLE_FLAGS (LO_FLAGS_AUTOCLEAR | LO_FLAGS_PARTSCAN)
+
+/* LO_FLAGS that can be cleared using LOOP_SET_STATUS(64) */
+#define LOOP_SET_STATUS_CLEARABLE_FLAGS (LO_FLAGS_AUTOCLEAR)
+
#include <asm/posix_types.h> /* for __kernel_old_dev_t */
#include <linux/types.h> /* for __u64 */
@@ -37,7 +43,7 @@ struct loop_info {
int lo_offset;
int lo_encrypt_type;
int lo_encrypt_key_size; /* ioctl w/o */
- int lo_flags; /* ioctl r/o */
+ int lo_flags;
char lo_name[LO_NAME_SIZE];
unsigned char lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */
unsigned long lo_init[2];
@@ -53,7 +59,7 @@ struct loop_info64 {
__u32 lo_number; /* ioctl r/o */
__u32 lo_encrypt_type;
__u32 lo_encrypt_key_size; /* ioctl w/o */
- __u32 lo_flags; /* ioctl r/o */
+ __u32 lo_flags;
__u8 lo_file_name[LO_NAME_SIZE];
__u8 lo_crypt_name[LO_NAME_SIZE];
__u8 lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */
--
2.26.2.303.gf8c07b1a785-goog
next prev parent reply other threads:[~2020-04-29 14:04 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 ` [PATCH v4 04/10] loop: Refactor loop_set_status() size calculation Martijn Coenen
2020-05-01 17:30 ` 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 ` Martijn Coenen [this message]
2020-05-06 6:08 ` [PATCH v4 09/10] loop: Clean up LOOP_SET_STATUS lo_flags handling 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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