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authorJohn Garry <john.g.garry@oracle.com>2024-06-20 14:53:56 +0200
committerJens Axboe <axboe@kernel.dk>2024-06-20 23:19:17 +0200
commitcaf336f81b3a3ca744e335972e86ec7244512d4a (patch)
treedc5bf0641a35c57fd39f279f1d8343dee3ce26ef /block/fops.c
parentblock: Add atomic write support for statx (diff)
downloadlinux-caf336f81b3a3ca744e335972e86ec7244512d4a.tar.xz
linux-caf336f81b3a3ca744e335972e86ec7244512d4a.zip
block: Add fops atomic write support
Support atomic writes by submitting a single BIO with the REQ_ATOMIC set. It must be ensured that the atomic write adheres to its rules, like naturally aligned offset, so call blkdev_dio_invalid() -> blkdev_atomic_write_valid() [with renaming blkdev_dio_unaligned() to blkdev_dio_invalid()] for this purpose. The BIO submission path currently checks for atomic writes which are too large, so no need to check here. In blkdev_direct_IO(), if the nr_pages exceeds BIO_MAX_VECS, then we cannot produce a single BIO, so error in this case. Finally set FMODE_CAN_ATOMIC_WRITE when the bdev can support atomic writes and the associated file flag is for O_DIRECT. Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Keith Busch <kbusch@kernel.org> Acked-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Link: https://lore.kernel.org/r/20240620125359.2684798-8-john.g.garry@oracle.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/fops.c')
-rw-r--r--block/fops.c20
1 files changed, 17 insertions, 3 deletions
diff --git a/block/fops.c b/block/fops.c
index 376265935714..be36c9fbd500 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -34,9 +34,12 @@ static blk_opf_t dio_bio_write_op(struct kiocb *iocb)
return opf;
}
-static bool blkdev_dio_unaligned(struct block_device *bdev, loff_t pos,
- struct iov_iter *iter)
+static bool blkdev_dio_invalid(struct block_device *bdev, loff_t pos,
+ struct iov_iter *iter, bool is_atomic)
{
+ if (is_atomic && !generic_atomic_write_valid(iter, pos))
+ return true;
+
return pos & (bdev_logical_block_size(bdev) - 1) ||
!bdev_iter_is_aligned(bdev, iter);
}
@@ -72,6 +75,8 @@ static ssize_t __blkdev_direct_IO_simple(struct kiocb *iocb,
bio.bi_iter.bi_sector = pos >> SECTOR_SHIFT;
bio.bi_write_hint = file_inode(iocb->ki_filp)->i_write_hint;
bio.bi_ioprio = iocb->ki_ioprio;
+ if (iocb->ki_flags & IOCB_ATOMIC)
+ bio.bi_opf |= REQ_ATOMIC;
ret = bio_iov_iter_get_pages(&bio, iter);
if (unlikely(ret))
@@ -343,6 +348,9 @@ static ssize_t __blkdev_direct_IO_async(struct kiocb *iocb,
task_io_account_write(bio->bi_iter.bi_size);
}
+ if (iocb->ki_flags & IOCB_ATOMIC)
+ bio->bi_opf |= REQ_ATOMIC;
+
if (iocb->ki_flags & IOCB_NOWAIT)
bio->bi_opf |= REQ_NOWAIT;
@@ -359,12 +367,13 @@ 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_unaligned(bdev, iocb->ki_pos, iter))
+ if (blkdev_dio_invalid(bdev, iocb->ki_pos, iter, is_atomic))
return -EINVAL;
nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS + 1);
@@ -373,6 +382,8 @@ 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) {
+ return -EINVAL;
}
return __blkdev_direct_IO(iocb, iter, bdev, bio_max_segs(nr_pages));
}
@@ -612,6 +623,9 @@ 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)
+ filp->f_mode |= FMODE_CAN_ATOMIC_WRITE;
+
ret = bdev_open(bdev, mode, filp->private_data, NULL, filp);
if (ret)
blkdev_put_no_open(bdev);