Create a new ceph_fscache_req structure that holds a fscache_io_request
and a refcount_t. Change the readpage code to use the new
infrastructure. Have KConfig select FSCACHE_SUPPORT so that it will
still work even when FSCache proper is disabled.
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
fs/ceph/Kconfig | 1 +
fs/ceph/addr.c | 204 +++++++++++++++++++++++++++++++++++++++++++++---
2 files changed, 195 insertions(+), 10 deletions(-)
diff --git a/fs/ceph/Kconfig b/fs/ceph/Kconfig
index e955a38be3c8..734d08b57ef9 100644
--- a/fs/ceph/Kconfig
+++ b/fs/ceph/Kconfig
@@ -6,6 +6,7 @@ config CEPH_FS
select LIBCRC32C
select CRYPTO_AES
select CRYPTO
+ select FSCACHE_SUPPORT
default n
help
Choose Y or M here to include support for mounting the
diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 1dbc4adbfc72..98f5edbf70b6 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -12,6 +12,7 @@
#include <linux/signal.h>
#include <linux/iversion.h>
#include <linux/ktime.h>
+#include <linux/fscache.h>
#include "super.h"
#include "mds_client.h"
@@ -182,6 +183,199 @@ static int ceph_releasepage(struct page *page, gfp_t g)
return 1;
}
+struct ceph_fscache_req {
+ struct fscache_io_request fscache_req;
+ refcount_t ref;
+};
+
+static struct ceph_fscache_req *ceph_fsreq_alloc(void)
+{
+ struct ceph_fscache_req *req = kzalloc(sizeof(*req), GFP_NOFS);
+
+ if (req)
+ refcount_set(&req->ref, 1);
+ return req;
+}
+
+static void ceph_fsreq_done(struct fscache_io_request *fsreq)
+{
+}
+
+static void ceph_fsreq_get(struct fscache_io_request *fsreq)
+{
+ struct ceph_fscache_req *req = container_of(fsreq, struct ceph_fscache_req, fscache_req);
+
+ refcount_inc(&req->ref);
+}
+
+static void ceph_fsreq_put(struct fscache_io_request *fsreq)
+{
+ struct ceph_fscache_req *req = container_of(fsreq, struct ceph_fscache_req, fscache_req);
+
+ if (refcount_dec_and_test(&req->ref)) {
+ fscache_free_io_request(fsreq);
+ kfree(req);
+ }
+}
+
+static void ceph_fsreq_reshape(struct fscache_io_request *fsreq,
+ struct fscache_request_shape *shape)
+{
+ struct inode *inode = fsreq->mapping->host;
+ struct ceph_inode_info *ci = ceph_inode(inode);
+ u64 objno, objoff;
+ u32 xlen;
+
+ /* Truncate the extent at the end of the current object */
+ ceph_calc_file_object_mapping(&ci->i_layout, shape->actual_start << PAGE_SHIFT,
+ shape->actual_nr_pages << PAGE_SHIFT, &objno, &objoff, &xlen);
+ shape->actual_nr_pages = xlen >> PAGE_SHIFT;
+}
+
+static void finish_fsreq_read(struct ceph_osd_request *req)
+{
+ struct ceph_fs_client *fsc = ceph_inode_to_client(req->r_inode);
+ struct ceph_osd_data *osd_data = osd_req_op_extent_osd_data(req, 0);
+ struct fscache_io_request *fsreq = req->r_priv;
+ int num_pages;
+ int err = req->r_result;
+
+ ceph_update_read_latency(&fsc->mdsc->metric, req->r_start_latency,
+ req->r_end_latency, err);
+
+ /* no object means success but no data */
+ if (err == -ENOENT)
+ err = 0;
+ else if (err == -EBLACKLISTED)
+ fsc->blacklisted = true;
+
+ dout("%s: result %d\n", __func__, err);
+ if (err >= 0)
+ fsreq->transferred = err;
+ else
+ fsreq->error = err;
+
+ if (fsreq->io_done)
+ fsreq->io_done(fsreq);
+
+ num_pages = calc_pages_for(osd_data->alignment, osd_data->length);
+ ceph_put_page_vector(osd_data->pages, num_pages, false);
+ ceph_fsreq_put(fsreq);
+ iput(req->r_inode);
+}
+
+static void ceph_fsreq_issue_op(struct fscache_io_request *fsreq)
+{
+ struct inode *inode = fsreq->mapping->host;
+ struct ceph_inode_info *ci = ceph_inode(inode);
+ struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
+ struct ceph_osd_request *req = NULL;
+ struct ceph_vino vino = ceph_vino(inode);
+ struct iov_iter iter;
+ struct page **pages;
+ size_t page_off;
+ int err = 0;
+ u64 len = fsreq->len;
+
+ req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout, vino, fsreq->pos, &len,
+ 0, 1, CEPH_OSD_OP_READ,
+ CEPH_OSD_FLAG_READ | fsc->client->osdc.client->options->read_from_replica,
+ NULL, ci->i_truncate_seq, ci->i_truncate_size, false);
+ if (IS_ERR(req)) {
+ err = PTR_ERR(req);
+ goto out;
+ }
+
+ dout("%s: pos=%llu orig_len=%llu len=%llu\n", __func__, fsreq->pos, fsreq->len, len);
+ iov_iter_mapping(&iter, READ, fsreq->mapping, fsreq->pos, len);
+ len = iov_iter_get_pages_alloc(&iter, &pages, len, &page_off);
+ if (len < 0) {
+ err = len;
+ dout("%s: iov_ter_get_pages_alloc returned %d\n", __func__, err);
+ goto out;
+ }
+
+ /* fscache should always give us a page-aligned read */
+ WARN_ON_ONCE(page_off);
+
+ osd_req_op_extent_osd_data_pages(req, 0, pages, len, 0, false, false);
+ req->r_callback = finish_fsreq_read;
+ req->r_priv = fsreq;
+ ceph_fsreq_get(fsreq);
+ req->r_inode = inode;
+ ihold(inode);
+
+ err = ceph_osdc_start_request(req->r_osdc, req, false);
+ if (err) {
+ iput(inode);
+ ceph_fsreq_put(fsreq);
+ }
+out:
+ if (req)
+ ceph_osdc_put_request(req);
+
+ if (err) {
+ fsreq->error = err;
+ if (fsreq->io_done)
+ fsreq->io_done(fsreq);
+ }
+ dout("%s: result %d\n", __func__, fsreq->error);
+}
+
+const struct fscache_io_request_ops ceph_readpage_fsreq_ops = {
+ .issue_op = ceph_fsreq_issue_op,
+ .reshape = ceph_fsreq_reshape,
+ .done = ceph_fsreq_done,
+ .get = ceph_fsreq_get,
+ .put = ceph_fsreq_put,
+};
+
+/* read a single page, without unlocking it. */
+static int ceph_readpage(struct file *filp, struct page *page)
+{
+ struct inode *inode = file_inode(filp);
+ struct ceph_inode_info *ci = ceph_inode(inode);
+ struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
+ struct ceph_fscache_req *req;
+ struct ceph_vino vino = ceph_vino(inode);
+ struct fscache_cookie *cookie = ceph_fscache_cookie(ci);
+ int err = 0;
+ u64 off = page_offset(page);
+ u64 len = PAGE_SIZE;
+
+ if (ci->i_inline_version != CEPH_INLINE_NONE) {
+ /*
+ * Uptodate inline data should have been added
+ * into page cache while getting Fcr caps.
+ */
+ if (off == 0) {
+ unlock_page(page);
+ return -EINVAL;
+ }
+ zero_user_segment(page, 0, PAGE_SIZE);
+ SetPageUptodate(page);
+ unlock_page(page);
+ return 0;
+ }
+
+ dout("readpage ino %llx.%llx file %p off %llu len %llu page %p index %lu\n",
+ vino.ino, vino.snap, filp, off, len, page, page->index);
+
+ req = ceph_fsreq_alloc();
+ if (!req) {
+ unlock_page(page);
+ return -ENOMEM;
+ }
+
+ fscache_init_io_request(&req->fscache_req, cookie, &ceph_readpage_fsreq_ops);
+ req->fscache_req.mapping = inode->i_mapping;
+
+ err = fscache_read_helper_locked_page(&req->fscache_req, page,
+ fsc->mount_options->rsize >> PAGE_SHIFT);
+ ceph_fsreq_put(&req->fscache_req);
+ return err;
+}
+
/* read a single page, without unlocking it. */
static int ceph_do_readpage(struct file *filp, struct page *page)
{
@@ -253,16 +447,6 @@ static int ceph_do_readpage(struct file *filp, struct page *page)
return err < 0 ? err : 0;
}
-static int ceph_readpage(struct file *filp, struct page *page)
-{
- int r = ceph_do_readpage(filp, page);
- if (r != -EINPROGRESS)
- unlock_page(page);
- else
- r = 0;
- return r;
-}
-
/*
* Finish an async read(ahead) op.
*/
--
2.26.2
