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authorShin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>2021-11-09 13:47:22 +0300
committerJens Axboe <axboe@kernel.dk>2021-11-09 22:41:12 +0300
commit7607c44c157d343223510c8ffdf7206fdd2a6213 (patch)
tree5d583e2d24b462f62bad819bd52c45f50d6d16d9 /block
parentcb690f5238d71f543f4ce874aa59237cf53a877c (diff)
downloadlinux-7607c44c157d343223510c8ffdf7206fdd2a6213.tar.xz
block: Hold invalidate_lock in BLKDISCARD ioctl
When BLKDISCARD ioctl and data read race, the data read leaves stale page cache. To avoid the stale page cache, hold invalidate_lock of the block device file mapping. The stale page cache is observed when blktests test case block/009 is repeated hundreds of times. This patch can be applied back to the stable kernel version v5.15.y with slight patch edit. Rework is required for older stable kernels. Fixes: 351499a172c0 ("block: Invalidate cache on discard v2") Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> Cc: stable@vger.kernel.org # v5.15 Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20211109104723.835533-2-shinichiro.kawasaki@wdc.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
-rw-r--r--block/ioctl.c12
1 files changed, 9 insertions, 3 deletions
diff --git a/block/ioctl.c b/block/ioctl.c
index d6af0ac97e57..9fa87f64f703 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -113,6 +113,7 @@ static int blk_ioctl_discard(struct block_device *bdev, fmode_t mode,
uint64_t range[2];
uint64_t start, len;
struct request_queue *q = bdev_get_queue(bdev);
+ struct inode *inode = bdev->bd_inode;
int err;
if (!(mode & FMODE_WRITE))
@@ -135,12 +136,17 @@ static int blk_ioctl_discard(struct block_device *bdev, fmode_t mode,
if (start + len > bdev_nr_bytes(bdev))
return -EINVAL;
+ filemap_invalidate_lock(inode->i_mapping);
err = truncate_bdev_range(bdev, mode, start, start + len - 1);
if (err)
- return err;
+ goto fail;
+
+ err = blkdev_issue_discard(bdev, start >> 9, len >> 9,
+ GFP_KERNEL, flags);
- return blkdev_issue_discard(bdev, start >> 9, len >> 9,
- GFP_KERNEL, flags);
+fail:
+ filemap_invalidate_unlock(inode->i_mapping);
+ return err;
}
static int blk_ioctl_zeroout(struct block_device *bdev, fmode_t mode,