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 c3be7ebbbce5201e151f17e28a6c807602f369c9 ]
Currently FMODE_CAN_ATOMIC_WRITE is set if the bdev can atomic write and the file is open for direct IO. This does not work if the file is not opened for direct IO, yet fcntl(O_DIRECT) is used on the fd later.
Change to check for direct IO on a per-IO basis in generic_atomic_write_valid(). Since we want to report -EOPNOTSUPP for non-direct IO for an atomic write, change to return an error code.
Relocate the block fops atomic write checks to the common write path, as to catch non-direct IO.
Fixes: c34fc6f26ab8 ("fs: Initial atomic write support") Reviewed-by: Christoph Hellwig hch@lst.de Reviewed-by: Darrick J. Wong djwong@kernel.org Signed-off-by: John Garry john.g.garry@oracle.com Link: https://lore.kernel.org/r/20241019125113.369994-3-john.g.garry@oracle.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- block/fops.c | 18 ++++++++++-------- fs/read_write.c | 13 ++++++++----- include/linux/fs.h | 2 +- 3 files changed, 19 insertions(+), 14 deletions(-)
diff --git a/block/fops.c b/block/fops.c index 1c0f9d3138451..56db751bba49b 100644 --- a/block/fops.c +++ b/block/fops.c @@ -35,11 +35,8 @@ static blk_opf_t dio_bio_write_op(struct kiocb *iocb) }
static bool blkdev_dio_invalid(struct block_device *bdev, struct kiocb *iocb, - struct iov_iter *iter, bool is_atomic) + struct iov_iter *iter) { - if (is_atomic && !generic_atomic_write_valid(iocb, iter)) - return true; - return iocb->ki_pos & (bdev_logical_block_size(bdev) - 1) || !bdev_iter_is_aligned(bdev, iter); } @@ -367,13 +364,12 @@ static ssize_t __blkdev_direct_IO_async(struct kiocb *iocb, static ssize_t blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter) { struct block_device *bdev = I_BDEV(iocb->ki_filp->f_mapping->host); - bool is_atomic = iocb->ki_flags & IOCB_ATOMIC; unsigned int nr_pages;
if (!iov_iter_count(iter)) return 0;
- if (blkdev_dio_invalid(bdev, iocb, iter, is_atomic)) + if (blkdev_dio_invalid(bdev, iocb, iter)) return -EINVAL;
nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS + 1); @@ -382,7 +378,7 @@ static ssize_t blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter) return __blkdev_direct_IO_simple(iocb, iter, bdev, nr_pages); return __blkdev_direct_IO_async(iocb, iter, bdev, nr_pages); - } else if (is_atomic) { + } else if (iocb->ki_flags & IOCB_ATOMIC) { return -EINVAL; } return __blkdev_direct_IO(iocb, iter, bdev, bio_max_segs(nr_pages)); @@ -624,7 +620,7 @@ static int blkdev_open(struct inode *inode, struct file *filp) if (!bdev) return -ENXIO;
- if (bdev_can_atomic_write(bdev) && filp->f_flags & O_DIRECT) + if (bdev_can_atomic_write(bdev)) filp->f_mode |= FMODE_CAN_ATOMIC_WRITE;
ret = bdev_open(bdev, mode, filp->private_data, NULL, filp); @@ -699,6 +695,12 @@ 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) { + ret = generic_atomic_write_valid(iocb, from); + if (ret) + return ret; + } + size -= iocb->ki_pos; if (iov_iter_count(from) > size) { shorted = iov_iter_count(from) - size; diff --git a/fs/read_write.c b/fs/read_write.c index d8af6f2f1c9af..1b122ec6d8f0d 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -1737,18 +1737,21 @@ int generic_file_rw_checks(struct file *file_in, struct file *file_out) return 0; }
-bool generic_atomic_write_valid(struct kiocb *iocb, struct iov_iter *iter) +int generic_atomic_write_valid(struct kiocb *iocb, struct iov_iter *iter) { size_t len = iov_iter_count(iter);
if (!iter_is_ubuf(iter)) - return false; + return -EINVAL;
if (!is_power_of_2(len)) - return false; + return -EINVAL;
if (!IS_ALIGNED(iocb->ki_pos, len)) - return false; + return -EINVAL;
- return true; + if (!(iocb->ki_flags & IOCB_DIRECT)) + return -EOPNOTSUPP; + + return 0; } diff --git a/include/linux/fs.h b/include/linux/fs.h index 0a8acd6063896..232b56416ccd9 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3663,6 +3663,6 @@ static inline bool vfs_empty_path(int dfd, const char __user *path) return !c; }
-bool generic_atomic_write_valid(struct kiocb *iocb, struct iov_iter *iter); +int generic_atomic_write_valid(struct kiocb *iocb, struct iov_iter *iter);
#endif /* _LINUX_FS_H */