From: John Garry <john.g.garry@oracle.com> mainline inclusion from mainline-v6.12-rc4 commit 2cbd51f1f8739fd2fdf4bae1386bcf75ce0176ba category: bugfix bugzilla: https://atomgit.com/openeuler/kernel/issues/8862 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- A write which goes past the end of the bdev in blkdev_write_iter() will be truncated. Truncating cannot tolerated for an atomic write, so error that condition. Fixes: caf336f81b3a ("block: Add fops atomic write support") Signed-off-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20241127092318.632790-1-john.g.garry@oracle.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Long Li <leo.lilong@huawei.com> --- block/fops.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/block/fops.c b/block/fops.c index fda001b04360..c6d49d2e0fcb 100644 --- a/block/fops.c +++ b/block/fops.c @@ -663,6 +663,7 @@ static ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) struct file *file = iocb->ki_filp; struct block_device *bdev = I_BDEV(file->f_mapping->host); struct inode *bd_inode = bdev->bd_inode; + bool atomic = iocb->ki_flags & IOCB_ATOMIC; loff_t size = bdev_nr_bytes(bdev); size_t shorted = 0; ssize_t ret; @@ -682,7 +683,7 @@ static ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) if ((iocb->ki_flags & (IOCB_NOWAIT | IOCB_DIRECT)) == IOCB_NOWAIT) return -EOPNOTSUPP; - if (iocb->ki_flags & IOCB_ATOMIC) { + if (atomic) { ret = generic_atomic_write_valid(iocb, from); if (ret) return ret; @@ -690,6 +691,8 @@ static ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) size -= iocb->ki_pos; if (iov_iter_count(from) > size) { + if (atomic) + return -EINVAL; shorted = iov_iter_count(from) - size; iov_iter_truncate(from, size); } -- 2.52.0