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authorMartijn Coenen <maco@android.com>2020-05-13 15:38:44 +0200
committerJens Axboe <axboe@kernel.dk>2020-05-21 16:20:35 +0200
commitfaf1d25440d6ad06d509dada4b6fe62fea844370 (patch)
treeedf4e1c5f3dbc56b7545bc317d9d68366bfe02b8 /drivers/block/loop.c
parentloop: Rework lo_ioctl() __user argument casting (diff)
downloadlinux-faf1d25440d6ad06d509dada4b6fe62fea844370.tar.xz
linux-faf1d25440d6ad06d509dada4b6fe62fea844370.zip
loop: Clean up LOOP_SET_STATUS lo_flags handling
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> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/block/loop.c')
-rw-r--r--drivers/block/loop.c19
1 files changed, 13 insertions, 6 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 31f10da4945e..13518ba191f5 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1036,9 +1036,7 @@ 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];
@@ -1323,6 +1321,7 @@ 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;
@@ -1359,10 +1358,19 @@ 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) {
loff_t new_size = get_size(lo->lo_offset, lo->lo_sizelimit,
lo->lo_backing_file);
@@ -1377,9 +1385,8 @@ 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;