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authorShin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>2021-11-09 13:47:23 +0300
committerJens Axboe <axboe@kernel.dk>2021-11-09 22:41:12 +0300
commit35e4c6c1a2fc2eb11b9306e95cda1fa06a511948 (patch)
treec1eccdc97dcae1924e073b8f83885e5f7e166f47 /block
parent7607c44c157d343223510c8ffdf7206fdd2a6213 (diff)
downloadlinux-35e4c6c1a2fc2eb11b9306e95cda1fa06a511948.tar.xz
block: Hold invalidate_lock in BLKZEROOUT ioctl
When BLKZEROOUT 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 modified to call "blkdiscard -z" command and repeated hundreds of times. This patch can be applied back to the stable kernel version v5.15.y. Rework is required for older stable kernels. Fixes: 22dd6d356628 ("block: invalidate the page cache when issuing BLKZEROOUT") 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/20211109104723.835533-3-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 9fa87f64f703..0a1d10ac2e1a 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -154,6 +154,7 @@ static int blk_ioctl_zeroout(struct block_device *bdev, fmode_t mode,
{
uint64_t range[2];
uint64_t start, end, len;
+ struct inode *inode = bdev->bd_inode;
int err;
if (!(mode & FMODE_WRITE))
@@ -176,12 +177,17 @@ static int blk_ioctl_zeroout(struct block_device *bdev, fmode_t mode,
return -EINVAL;
/* Invalidate the page cache, including dirty pages */
+ filemap_invalidate_lock(inode->i_mapping);
err = truncate_bdev_range(bdev, mode, start, end);
if (err)
- return err;
+ goto fail;
+
+ err = blkdev_issue_zeroout(bdev, start >> 9, len >> 9, GFP_KERNEL,
+ BLKDEV_ZERO_NOUNMAP);
- return blkdev_issue_zeroout(bdev, start >> 9, len >> 9, GFP_KERNEL,
- BLKDEV_ZERO_NOUNMAP);
+fail:
+ filemap_invalidate_unlock(inode->i_mapping);
+ return err;
}
static int put_ushort(unsigned short __user *argp, unsigned short val)