Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 364 insertions, 0 deletions

diff --git a/fs/ceph/cache.c b/fs/ceph/cache.c
new file mode 100644
index 000000000..1bf3502bd
--- /dev/null
+++ b/fs/ceph/cache.c
@@ -0,0 +1,364 @@
+/*
+ * Ceph cache definitions.
+ *
+ *  Copyright (C) 2013 by Adfin Solutions, Inc. All Rights Reserved.
+ *  Written by Milosz Tanski (milosz@adfin.com)
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2
+ *  as published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to:
+ *  Free Software Foundation
+ *  51 Franklin Street, Fifth Floor
+ *  Boston, MA  02111-1301  USA
+ *
+ */
+
+#include "super.h"
+#include "cache.h"
+
+struct ceph_aux_inode {
+	u64 	version;
+	u64	mtime_sec;
+	u64	mtime_nsec;
+};
+
+struct fscache_netfs ceph_cache_netfs = {
+	.name		= "ceph",
+	.version	= 0,
+};
+
+static DEFINE_MUTEX(ceph_fscache_lock);
+static LIST_HEAD(ceph_fscache_list);
+
+struct ceph_fscache_entry {
+	struct list_head list;
+	struct fscache_cookie *fscache;
+	size_t uniq_len;
+	/* The following members must be last */
+	struct ceph_fsid fsid;
+	char uniquifier[0];
+};
+
+static const struct fscache_cookie_def ceph_fscache_fsid_object_def = {
+	.name		= "CEPH.fsid",
+	.type		= FSCACHE_COOKIE_TYPE_INDEX,
+};
+
+int __init ceph_fscache_register(void)
+{
+	return fscache_register_netfs(&ceph_cache_netfs);
+}
+
+void ceph_fscache_unregister(void)
+{
+	fscache_unregister_netfs(&ceph_cache_netfs);
+}
+
+int ceph_fscache_register_fs(struct ceph_fs_client* fsc)
+{
+	const struct ceph_fsid *fsid = &fsc->client->fsid;
+	const char *fscache_uniq = fsc->mount_options->fscache_uniq;
+	size_t uniq_len = fscache_uniq ? strlen(fscache_uniq) : 0;
+	struct ceph_fscache_entry *ent;
+	int err = 0;
+
+	mutex_lock(&ceph_fscache_lock);
+	list_for_each_entry(ent, &ceph_fscache_list, list) {
+		if (memcmp(&ent->fsid, fsid, sizeof(*fsid)))
+			continue;
+		if (ent->uniq_len != uniq_len)
+			continue;
+		if (uniq_len && memcmp(ent->uniquifier, fscache_uniq, uniq_len))
+			continue;
+
+		pr_err("fscache cookie already registered for fsid %pU\n", fsid);
+		pr_err("  use fsc=%%s mount option to specify a uniquifier\n");
+		err = -EBUSY;
+		goto out_unlock;
+	}
+
+	ent = kzalloc(sizeof(*ent) + uniq_len, GFP_KERNEL);
+	if (!ent) {
+		err = -ENOMEM;
+		goto out_unlock;
+	}
+
+	memcpy(&ent->fsid, fsid, sizeof(*fsid));
+	if (uniq_len > 0) {
+		memcpy(&ent->uniquifier, fscache_uniq, uniq_len);
+		ent->uniq_len = uniq_len;
+	}
+
+	fsc->fscache = fscache_acquire_cookie(ceph_cache_netfs.primary_index,
+					      &ceph_fscache_fsid_object_def,
+					      &ent->fsid, sizeof(ent->fsid) + uniq_len,
+					      NULL, 0,
+					      fsc, 0, true);
+
+	if (fsc->fscache) {
+		ent->fscache = fsc->fscache;
+		list_add_tail(&ent->list, &ceph_fscache_list);
+	} else {
+		kfree(ent);
+		pr_err("unable to register fscache cookie for fsid %pU\n",
+		       fsid);
+		/* all other fs ignore this error */
+	}
+out_unlock:
+	mutex_unlock(&ceph_fscache_lock);
+	return err;
+}
+
+static enum fscache_checkaux ceph_fscache_inode_check_aux(
+	void *cookie_netfs_data, const void *data, uint16_t dlen,
+	loff_t object_size)
+{
+	struct ceph_aux_inode aux;
+	struct ceph_inode_info* ci = cookie_netfs_data;
+	struct inode* inode = &ci->vfs_inode;
+
+	if (dlen != sizeof(aux) ||
+	    i_size_read(inode) != object_size)
+		return FSCACHE_CHECKAUX_OBSOLETE;
+
+	memset(&aux, 0, sizeof(aux));
+	aux.version = ci->i_version;
+	aux.mtime_sec = inode->i_mtime.tv_sec;
+	aux.mtime_nsec = inode->i_mtime.tv_nsec;
+
+	if (memcmp(data, &aux, sizeof(aux)) != 0)
+		return FSCACHE_CHECKAUX_OBSOLETE;
+
+	dout("ceph inode 0x%p cached okay\n", ci);
+	return FSCACHE_CHECKAUX_OKAY;
+}
+
+static const struct fscache_cookie_def ceph_fscache_inode_object_def = {
+	.name		= "CEPH.inode",
+	.type		= FSCACHE_COOKIE_TYPE_DATAFILE,
+	.check_aux	= ceph_fscache_inode_check_aux,
+};
+
+void ceph_fscache_register_inode_cookie(struct inode *inode)
+{
+	struct ceph_inode_info *ci = ceph_inode(inode);
+	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
+	struct ceph_aux_inode aux;
+
+	/* No caching for filesystem */
+	if (!fsc->fscache)
+		return;
+
+	/* Only cache for regular files that are read only */
+	if (!S_ISREG(inode->i_mode))
+		return;
+
+	inode_lock_nested(inode, I_MUTEX_CHILD);
+	if (!ci->fscache) {
+		memset(&aux, 0, sizeof(aux));
+		aux.version = ci->i_version;
+		aux.mtime_sec = inode->i_mtime.tv_sec;
+		aux.mtime_nsec = inode->i_mtime.tv_nsec;
+		ci->fscache = fscache_acquire_cookie(fsc->fscache,
+						     &ceph_fscache_inode_object_def,
+						     &ci->i_vino, sizeof(ci->i_vino),
+						     &aux, sizeof(aux),
+						     ci, i_size_read(inode), false);
+	}
+	inode_unlock(inode);
+}
+
+void ceph_fscache_unregister_inode_cookie(struct ceph_inode_info* ci)
+{
+	struct fscache_cookie* cookie;
+
+	if ((cookie = ci->fscache) == NULL)
+		return;
+
+	ci->fscache = NULL;
+
+	fscache_uncache_all_inode_pages(cookie, &ci->vfs_inode);
+	fscache_relinquish_cookie(cookie, &ci->i_vino, false);
+}
+
+static bool ceph_fscache_can_enable(void *data)
+{
+	struct inode *inode = data;
+	return !inode_is_open_for_write(inode);
+}
+
+void ceph_fscache_file_set_cookie(struct inode *inode, struct file *filp)
+{
+	struct ceph_inode_info *ci = ceph_inode(inode);
+
+	if (!fscache_cookie_valid(ci->fscache))
+		return;
+
+	if (inode_is_open_for_write(inode)) {
+		dout("fscache_file_set_cookie %p %p disabling cache\n",
+		     inode, filp);
+		fscache_disable_cookie(ci->fscache, &ci->i_vino, false);
+		fscache_uncache_all_inode_pages(ci->fscache, inode);
+	} else {
+		fscache_enable_cookie(ci->fscache, &ci->i_vino, i_size_read(inode),
+				      ceph_fscache_can_enable, inode);
+		if (fscache_cookie_enabled(ci->fscache)) {
+			dout("fscache_file_set_cookie %p %p enabling cache\n",
+			     inode, filp);
+		}
+	}
+}
+
+static void ceph_readpage_from_fscache_complete(struct page *page, void *data, int error)
+{
+	if (!error)
+		SetPageUptodate(page);
+
+	unlock_page(page);
+}
+
+static inline bool cache_valid(struct ceph_inode_info *ci)
+{
+	return ci->i_fscache_gen == ci->i_rdcache_gen;
+}
+
+
+/* Atempt to read from the fscache,
+ *
+ * This function is called from the readpage_nounlock context. DO NOT attempt to
+ * unlock the page here (or in the callback).
+ */
+int ceph_readpage_from_fscache(struct inode *inode, struct page *page)
+{
+	struct ceph_inode_info *ci = ceph_inode(inode);
+	int ret;
+
+	if (!cache_valid(ci))
+		return -ENOBUFS;
+
+	ret = fscache_read_or_alloc_page(ci->fscache, page,
+					 ceph_readpage_from_fscache_complete, NULL,
+					 GFP_KERNEL);
+
+	switch (ret) {
+		case 0: /* Page found */
+			dout("page read submitted\n");
+			return 0;
+		case -ENOBUFS: /* Pages were not found, and can't be */
+		case -ENODATA: /* Pages were not found */
+			dout("page/inode not in cache\n");
+			return ret;
+		default:
+			dout("%s: unknown error ret = %i\n", __func__, ret);
+			return ret;
+	}
+}
+
+int ceph_readpages_from_fscache(struct inode *inode,
+				  struct address_space *mapping,
+				  struct list_head *pages,
+				  unsigned *nr_pages)
+{
+	struct ceph_inode_info *ci = ceph_inode(inode);
+	int ret;
+
+	if (!cache_valid(ci))
+		return -ENOBUFS;
+
+	ret = fscache_read_or_alloc_pages(ci->fscache, mapping, pages, nr_pages,
+					  ceph_readpage_from_fscache_complete,
+					  NULL, mapping_gfp_mask(mapping));
+
+	switch (ret) {
+		case 0: /* All pages found */
+			dout("all-page read submitted\n");
+			return 0;
+		case -ENOBUFS: /* Some pages were not found, and can't be */
+		case -ENODATA: /* some pages were not found */
+			dout("page/inode not in cache\n");
+			return ret;
+		default:
+			dout("%s: unknown error ret = %i\n", __func__, ret);
+			return ret;
+	}
+}
+
+void ceph_readpage_to_fscache(struct inode *inode, struct page *page)
+{
+	struct ceph_inode_info *ci = ceph_inode(inode);
+	int ret;
+
+	if (!PageFsCache(page))
+		return;
+
+	if (!cache_valid(ci))
+		return;
+
+	ret = fscache_write_page(ci->fscache, page, i_size_read(inode),
+				 GFP_KERNEL);
+	if (ret)
+		 fscache_uncache_page(ci->fscache, page);
+}
+
+void ceph_invalidate_fscache_page(struct inode* inode, struct page *page)
+{
+	struct ceph_inode_info *ci = ceph_inode(inode);
+
+	if (!PageFsCache(page))
+		return;
+
+	fscache_wait_on_page_write(ci->fscache, page);
+	fscache_uncache_page(ci->fscache, page);
+}
+
+void ceph_fscache_unregister_fs(struct ceph_fs_client* fsc)
+{
+	if (fscache_cookie_valid(fsc->fscache)) {
+		struct ceph_fscache_entry *ent;
+		bool found = false;
+
+		mutex_lock(&ceph_fscache_lock);
+		list_for_each_entry(ent, &ceph_fscache_list, list) {
+			if (ent->fscache == fsc->fscache) {
+				list_del(&ent->list);
+				kfree(ent);
+				found = true;
+				break;
+			}
+		}
+		WARN_ON_ONCE(!found);
+		mutex_unlock(&ceph_fscache_lock);
+
+		__fscache_relinquish_cookie(fsc->fscache, NULL, false);
+	}
+	fsc->fscache = NULL;
+}
+
+/*
+ * caller should hold CEPH_CAP_FILE_{RD,CACHE}
+ */
+void ceph_fscache_revalidate_cookie(struct ceph_inode_info *ci)
+{
+	if (cache_valid(ci))
+		return;
+
+	/* resue i_truncate_mutex. There should be no pending
+	 * truncate while the caller holds CEPH_CAP_FILE_RD */
+	mutex_lock(&ci->i_truncate_mutex);
+	if (!cache_valid(ci)) {
+		if (fscache_check_consistency(ci->fscache, &ci->i_vino))
+			fscache_invalidate(ci->fscache);
+		spin_lock(&ci->i_ceph_lock);
+		ci->i_fscache_gen = ci->i_rdcache_gen;
+		spin_unlock(&ci->i_ceph_lock);
+	}
+	mutex_unlock(&ci->i_truncate_mutex);
+}