Commit a5c9dc44 authored by David Howells's avatar David Howells
Browse files

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: default avatarDavid 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
parent 2de16041

fs/ceph/addr.c

+41 −28
Original line number Diff line number Diff line
@@ -354,6 +354,45 @@ static void ceph_netfs_issue_read(struct netfs_io_subrequest *subreq) 
	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