ceph: Make ceph_init_request() check caps on readahead

Move the caps check from ceph_readahead() to ceph_init_request(),
conditional on the origin being NETFS_READAHEAD so that in a future patch,
ceph can point its ->readahead() vector directly at netfs_readahead().

Changes
=======
ver #4)
 - Move the check for NETFS_READAHEAD up in ceph_init_request()[2].

ver #3)
 - Split from the patch to add a netfs inode context[1].
 - Need to store the caps got in rreq->netfs_priv for later freeing.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: ceph-devel@vger.kernel.org
cc: linux-cachefs@redhat.com

Link: https://lore.kernel.org/r/8af0d47f17d89c06bbf602496dd845f2b0bf25b3.camel@kernel.org/ [1]
Link: https://lore.kernel.org/r/dd054c962818716e718bd9b446ee5322ca097675.camel@redhat.com/ [2]
Link: https://lore.kernel.org/r/164692907694.2099075.10081819855690054094.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/2533821.1647006574@warthog.procyon.org.uk/ # v4
This commit is contained in:
David Howells 2022-03-09 21:45:22 +00:00
parent 2de1604173
commit a5c9dc4451

View File

@ -354,6 +354,45 @@ out:
dout("%s: result %d\n", __func__, err);
}
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;
int ret = 0;
if (rreq->origin != NETFS_READAHEAD)
return 0;
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)
return 0;
}
/*
* readahead callers do not necessarily hold Fcb caps
* (e.g. fadvise, madvise).
*/
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;
}
if (!(got & want)) {
dout("start_read %p, no cache cap\n", inode);
return -EACCES;
}
if (ret == 0)
return -EACCES;
rreq->netfs_priv = (void *)(uintptr_t)got;
return 0;
}
static void ceph_readahead_cleanup(struct address_space *mapping, void *priv)
{
struct inode *inode = mapping->host;
@ -365,7 +404,7 @@ static void ceph_readahead_cleanup(struct address_space *mapping, void *priv)
}
static const struct netfs_request_ops ceph_netfs_read_ops = {
.is_cache_enabled = ceph_is_cache_enabled,
.init_request = ceph_init_request,
.begin_cache_operation = ceph_begin_cache_operation,
.issue_read = ceph_netfs_issue_read,
.expand_readahead = ceph_netfs_expand_readahead,
@ -393,33 +432,7 @@ static int ceph_readpage(struct file *file, struct page *subpage)
static void ceph_readahead(struct readahead_control *ractl)
{
struct inode *inode = file_inode(ractl->file);
struct ceph_file_info *fi = ractl->file->private_data;
struct ceph_rw_context *rw_ctx;
int got = 0;
int ret = 0;
if (ceph_inode(inode)->i_inline_version != CEPH_INLINE_NONE)
return;
rw_ctx = ceph_find_rw_context(fi);
if (!rw_ctx) {
/*
* readahead callers do not necessarily hold Fcb caps
* (e.g. fadvise, madvise).
*/
int want = CEPH_CAP_FILE_CACHE;
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);
else if (!(got & want))
dout("start_read %p, no cache cap\n", inode);
if (ret <= 0)
return;
}
netfs_readahead(ractl, &ceph_netfs_read_ops, (void *)(uintptr_t)got);
netfs_readahead(ractl, &ceph_netfs_read_ops, NULL);
}
#ifdef CONFIG_CEPH_FSCACHE