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| author | Miklos Szeredi <mszeredi@redhat.com> | 2021-09-27 11:23:57 +0200 |
|---|---|---|
| committer | Miklos Szeredi <mszeredi@redhat.com> | 2021-09-28 09:16:12 +0200 |
| commit | 1dc1eed46f9fa4cb8a07baa24fb44c96d6dd35c9 (patch) | |
| tree | bdd3994a59af1aadf9552c99516cd2f6cd994302 | |
| parent | a295aef603e109a47af355477326bd41151765b6 (diff) | |
| download | linux-1dc1eed46f9fa4cb8a07baa24fb44c96d6dd35c9.tar.bz2 | |
ovl: fix IOCB_DIRECT if underlying fs doesn't support direct IO
Normally the check at open time suffices, but e.g loop device does set
IOCB_DIRECT after doing its own checks (which are not sufficent for
overlayfs).
Make sure we don't call the underlying filesystem read/write method with
the IOCB_DIRECT if it's not supported.
Reported-by: Huang Jianan <huangjianan@oppo.com>
Fixes: 16914e6fc7e1 ("ovl: add ovl_read_iter()")
Cc: <stable@vger.kernel.org> # v4.19
Tested-by: Huang Jianan <huangjianan@oppo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| -rw-r--r-- | fs/overlayfs/file.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c index d081faa55e83..c88ac571593d 100644 --- a/fs/overlayfs/file.c +++ b/fs/overlayfs/file.c @@ -296,6 +296,12 @@ static ssize_t ovl_read_iter(struct kiocb *iocb, struct iov_iter *iter) if (ret) return ret; + ret = -EINVAL; + if (iocb->ki_flags & IOCB_DIRECT && + (!real.file->f_mapping->a_ops || + !real.file->f_mapping->a_ops->direct_IO)) + goto out_fdput; + old_cred = ovl_override_creds(file_inode(file)->i_sb); if (is_sync_kiocb(iocb)) { ret = vfs_iter_read(real.file, iter, &iocb->ki_pos, @@ -320,7 +326,7 @@ static ssize_t ovl_read_iter(struct kiocb *iocb, struct iov_iter *iter) out: revert_creds(old_cred); ovl_file_accessed(file); - +out_fdput: fdput(real); return ret; @@ -349,6 +355,12 @@ static ssize_t ovl_write_iter(struct kiocb *iocb, struct iov_iter *iter) if (ret) goto out_unlock; + ret = -EINVAL; + if (iocb->ki_flags & IOCB_DIRECT && + (!real.file->f_mapping->a_ops || + !real.file->f_mapping->a_ops->direct_IO)) + goto out_fdput; + if (!ovl_should_sync(OVL_FS(inode->i_sb))) ifl &= ~(IOCB_DSYNC | IOCB_SYNC); @@ -384,6 +396,7 @@ static ssize_t ovl_write_iter(struct kiocb *iocb, struct iov_iter *iter) } out: revert_creds(old_cred); +out_fdput: fdput(real); out_unlock: |