6.11-stable review patch. If anyone has any objections, please let me know.
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From: John Garry john.g.garry@oracle.com
[ Upstream commit 2cbd51f1f8739fd2fdf4bae1386bcf75ce0176ba ]
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: Sasha Levin sashal@kernel.org --- block/fops.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/block/fops.c b/block/fops.c index 56db751bba49b..16bb5ae702379 100644 --- a/block/fops.c +++ b/block/fops.c @@ -676,6 +676,7 @@ static ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) struct file *file = iocb->ki_filp; struct inode *bd_inode = bdev_file_inode(file); struct block_device *bdev = I_BDEV(bd_inode); + bool atomic = iocb->ki_flags & IOCB_ATOMIC; loff_t size = bdev_nr_bytes(bdev); size_t shorted = 0; ssize_t ret; @@ -695,7 +696,7 @@ 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; @@ -703,6 +704,8 @@ 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); }