On Thu, May 11, 2023 at 11:03:34AM +0800, xiubli@xxxxxxxxxx wrote:
> From: Xiubo Li <xiubli@xxxxxxxxxx>
>
> We need to save the 'f_ra.ra_pages' to expand the readahead window
> later.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: 49870056005c ("ceph: convert ceph_readpages to ceph_readahead")
> URL: https://lore.kernel.org/ceph-devel/20230504082510.247-1-sehuww@xxxxxxxxxxxxxxxx
> URL: https://www.spinics.net/lists/ceph-users/msg76183.html
> Cc: Hu Weiwen <sehuww@xxxxxxxxxxxxxxxx>
> Signed-off-by: Xiubo Li <xiubli@xxxxxxxxxx>
> ---
> fs/ceph/addr.c | 43 ++++++++++++++++++++++++++++++++-----------
> fs/ceph/super.h | 13 +++++++++++++
> 2 files changed, 45 insertions(+), 11 deletions(-)
>
> diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
> index 3b20873733af..db55fce13324 100644
> --- a/fs/ceph/addr.c
> +++ b/fs/ceph/addr.c
> @@ -404,18 +404,27 @@ static int ceph_init_request(struct netfs_io_request *rreq, struct file *file)
> {
> struct inode *inode = rreq->inode;
> int got = 0, want = CEPH_CAP_FILE_CACHE;
> + struct ceph_netfs_request_data *priv;
> int ret = 0;
>
> if (rreq->origin != NETFS_READAHEAD)
> return 0;
>
> + priv = kzalloc(sizeof(*priv), GFP_NOFS);
> + if (!priv)
> + return -ENOMEM;
> +
> if (file) {
> struct ceph_rw_context *rw_ctx;
> struct ceph_file_info *fi = file->private_data;
>
> rw_ctx = ceph_find_rw_context(fi);
> - if (rw_ctx)
> + if (rw_ctx) {
> + kfree(priv);
> return 0;
This is not working. When reaching here by read() system call, we always
have non-null rw_ctx. (As I read the code and also verified with gdb)
ceph_add_rw_context() is invoked in ceph_read_iter().
> + }
> + priv->file_ra_pages = file->f_ra.ra_pages;
> + priv->file_ra_disabled = !!(file->f_mode & FMODE_RANDOM);
'!!' is not needed. From coding-style.rst: "When using bool types the
!! construction is not needed, which eliminates a class of bugs".
Thanks
Hu Weiwen
> }
>
> /*
> @@ -425,27 +434,39 @@ static int ceph_init_request(struct netfs_io_request *rreq, struct file *file)
> ret = ceph_try_get_caps(inode, CEPH_CAP_FILE_RD, want, true, &got);
> if (ret < 0) {
> dout("start_read %p, error getting cap\n", inode);
> - return ret;
> + goto out;
> }
>
> if (!(got & want)) {
> dout("start_read %p, no cache cap\n", inode);
> - return -EACCES;
> + ret = -EACCES;
> + goto out;
> + }
> + if (ret == 0) {
> + ret = -EACCES;
> + goto out;
> }
> - if (ret == 0)
> - return -EACCES;
>
> - rreq->netfs_priv = (void *)(uintptr_t)got;
> - return 0;
> + priv->caps = got;
> + rreq->netfs_priv = priv;
> +
> +out:
> + if (ret)
> + kfree(priv);
> +
> + return ret;
> }
>
> static void ceph_netfs_free_request(struct netfs_io_request *rreq)
> {
> - struct ceph_inode_info *ci = ceph_inode(rreq->inode);
> - int got = (uintptr_t)rreq->netfs_priv;
> + struct ceph_netfs_request_data *priv = rreq->netfs_priv;
> +
> + if (!priv)
> + return;
>
> - if (got)
> - ceph_put_cap_refs(ci, got);
> + ceph_put_cap_refs(ceph_inode(rreq->inode), priv->caps);
> + kfree(priv);
> + rreq->netfs_priv = NULL;
> }
>
> const struct netfs_request_ops ceph_netfs_ops = {
> diff --git a/fs/ceph/super.h b/fs/ceph/super.h
> index a226d36b3ecb..1233f53f6e0b 100644
> --- a/fs/ceph/super.h
> +++ b/fs/ceph/super.h
> @@ -470,6 +470,19 @@ struct ceph_inode_info {
> #endif
> };
>
> +struct ceph_netfs_request_data {
> + int caps;
> +
> + /*
> + * Maximum size of a file readahead request.
> + * The posix_fadvise could update the bdi's default ra_pages.
> + */
> + unsigned int file_ra_pages;
> +
> + /* Set it if posix_fadvise disables file readahead entirely */
> + bool file_ra_disabled;
> +};
> +
> static inline struct ceph_inode_info *
> ceph_inode(const struct inode *inode)
> {
> --
> 2.40.0
>
