diff options
| author | Christoph Hellwig <hch@lst.de> | 2019-09-19 15:32:45 -0700 |
|---|---|---|
| committer | Darrick J. Wong <darrick.wong@oracle.com> | 2019-09-19 15:32:45 -0700 |
| commit | 838c4f3d7515efe9d0e32c846fb5d102b6d8a29d (patch) | |
| tree | cd50fb73997130df5bd87700861aae7663702ed4 /fs | |
| parent | 6fe7b9901400152238e1b76198747f6716c78aad (diff) | |
| download | linux-838c4f3d7515efe9d0e32c846fb5d102b6d8a29d.tar.gz linux-838c4f3d7515efe9d0e32c846fb5d102b6d8a29d.tar.bz2 linux-838c4f3d7515efe9d0e32c846fb5d102b6d8a29d.zip | |
iomap: move the iomap_dio_rw ->end_io callback into a structure
Add a new iomap_dio_ops structure that for now just contains the end_io
handler. This avoid storing the function pointer in a mutable structure,
which is a possible exploit vector for kernel code execution, and prepares
for adding a submit_io handler that btrfs needs.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/iomap/direct-io.c | 21 | ||||
| -rw-r--r-- | fs/xfs/xfs_file.c | 6 |
2 files changed, 15 insertions, 12 deletions
diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c index 2ccf1c6460d4..1fc28c2da279 100644 --- a/fs/iomap/direct-io.c +++ b/fs/iomap/direct-io.c @@ -24,7 +24,7 @@ struct iomap_dio { struct kiocb *iocb; - iomap_dio_end_io_t *end_io; + const struct iomap_dio_ops *dops; loff_t i_size; loff_t size; atomic_t ref; @@ -72,15 +72,14 @@ static void iomap_dio_submit_bio(struct iomap_dio *dio, struct iomap *iomap, static ssize_t iomap_dio_complete(struct iomap_dio *dio) { + const struct iomap_dio_ops *dops = dio->dops; struct kiocb *iocb = dio->iocb; struct inode *inode = file_inode(iocb->ki_filp); loff_t offset = iocb->ki_pos; - ssize_t ret; + ssize_t ret = dio->error; - if (dio->end_io) - ret = dio->end_io(iocb, dio->size, dio->error, dio->flags); - else - ret = dio->error; + if (dops && dops->end_io) + ret = dops->end_io(iocb, dio->size, ret, dio->flags); if (likely(!ret)) { ret = dio->size; @@ -98,9 +97,9 @@ static ssize_t iomap_dio_complete(struct iomap_dio *dio) * one is a pretty crazy thing to do, so we don't support it 100%. If * this invalidation fails, tough, the write still worked... * - * And this page cache invalidation has to be after dio->end_io(), as - * some filesystems convert unwritten extents to real allocations in - * end_io() when necessary, otherwise a racing buffer read would cache + * And this page cache invalidation has to be after ->end_io(), as some + * filesystems convert unwritten extents to real allocations in + * ->end_io() when necessary, otherwise a racing buffer read would cache * zeros from unwritten extents. */ if (!dio->error && @@ -393,7 +392,7 @@ iomap_dio_actor(struct inode *inode, loff_t pos, loff_t length, */ ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, - const struct iomap_ops *ops, iomap_dio_end_io_t end_io) + const struct iomap_ops *ops, const struct iomap_dio_ops *dops) { struct address_space *mapping = iocb->ki_filp->f_mapping; struct inode *inode = file_inode(iocb->ki_filp); @@ -418,7 +417,7 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, atomic_set(&dio->ref, 1); dio->size = 0; dio->i_size = i_size_read(inode); - dio->end_io = end_io; + dio->dops = dops; dio->error = 0; dio->flags = 0; diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 74411296f6b5..21bd3d575aaa 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -442,6 +442,10 @@ out: return error; } +static const struct iomap_dio_ops xfs_dio_write_ops = { + .end_io = xfs_dio_write_end_io, +}; + /* * xfs_file_dio_aio_write - handle direct IO writes * @@ -542,7 +546,7 @@ xfs_file_dio_aio_write( } trace_xfs_file_direct_write(ip, count, iocb->ki_pos); - ret = iomap_dio_rw(iocb, from, &xfs_iomap_ops, xfs_dio_write_end_io); + ret = iomap_dio_rw(iocb, from, &xfs_iomap_ops, &xfs_dio_write_ops); /* * If unaligned, this is the only IO in-flight. If it has not yet |