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block: Hold invalidate_lock in BLKZEROOUT ioctl

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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: 22dd6d3566 ("block: invalidate the page cache when issuing BLKZEROOUT")
Signed-off-by: Shin'ichiro Kawasaki <[email protected]>
Cc: [email protected] # v5.15
Reviewed-by: Jan Kara <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>
This commit is contained in:
Shin'ichiro Kawasaki authored and Jens Axboe committed 2021-11-09 12:41:12 -07:00
1 parent 7607c44c15
commit 35e4c6c1a2
1 file changed
+9 -3
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block/ioctl.c
+9 -3
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@@ -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;
return blkdev_issue_zeroout(bdev, start >> 9, len >> 9, GFP_KERNEL,
BLKDEV_ZERO_NOUNMAP);
err = 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)