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authorJohn Garry <john.g.garry@oracle.com>2024-11-27 09:23:18 +0000
committerJens Axboe <axboe@kernel.dk>2024-11-27 15:04:57 -0700
commit2cbd51f1f8739fd2fdf4bae1386bcf75ce0176ba (patch)
tree42fd03ab77cd6c41742fe14a6f083d432c2ca3c8 /block
parent1b0cab327e060ccf397ae634a34c84dd1d4d2bb2 (diff)
block: Don't allow an atomic write be truncated in blkdev_write_iter()
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>
Diffstat (limited to 'block')
-rw-r--r--block/fops.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/block/fops.c b/block/fops.c
index 2d01c9007681..13a67940d040 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -677,6 +677,7 @@ 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;
@@ -696,7 +697,7 @@ 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;
@@ -704,6 +705,8 @@ 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);
}