--- /dev/null
+/*
+ * 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 {
+ struct timespec mtime;
+ loff_t size;
+};
+
+struct fscache_netfs ceph_cache_netfs = {
+ .name = "ceph",
+ .version = 0,
+};
+
+static uint16_t ceph_fscache_session_get_key(const void *cookie_netfs_data,
+ void *buffer, uint16_t maxbuf)
+{
+ const struct ceph_fs_client* fsc = cookie_netfs_data;
+ uint16_t klen;
+
+ klen = sizeof(fsc->client->fsid);
+ if (klen > maxbuf)
+ return 0;
+
+ memcpy(buffer, &fsc->client->fsid, klen);
+ return klen;
+}
+
+static const struct fscache_cookie_def ceph_fscache_fsid_object_def = {
+ .name = "CEPH.fsid",
+ .type = FSCACHE_COOKIE_TYPE_INDEX,
+ .get_key = ceph_fscache_session_get_key,
+};
+
+int 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)
+{
+ fsc->fscache = fscache_acquire_cookie(ceph_cache_netfs.primary_index,
+ &ceph_fscache_fsid_object_def,
+ fsc, true);
+
+ if (fsc->fscache == NULL) {
+ pr_err("Unable to resgister fsid: %p fscache cookie", fsc);
+ return 0;
+ }
+
+ fsc->revalidate_wq = alloc_workqueue("ceph-revalidate", 0, 1);
+ if (fsc->revalidate_wq == NULL)
+ return -ENOMEM;
+
+ return 0;
+}
+
+static uint16_t ceph_fscache_inode_get_key(const void *cookie_netfs_data,
+ void *buffer, uint16_t maxbuf)
+{
+ const struct ceph_inode_info* ci = cookie_netfs_data;
+ uint16_t klen;
+
+ /* use ceph virtual inode (id + snaphot) */
+ klen = sizeof(ci->i_vino);
+ if (klen > maxbuf)
+ return 0;
+
+ memcpy(buffer, &ci->i_vino, klen);
+ return klen;
+}
+
+static uint16_t ceph_fscache_inode_get_aux(const void *cookie_netfs_data,
+ void *buffer, uint16_t bufmax)
+{
+ struct ceph_aux_inode aux;
+ const struct ceph_inode_info* ci = cookie_netfs_data;
+ const struct inode* inode = &ci->vfs_inode;
+
+ memset(&aux, 0, sizeof(aux));
+ aux.mtime = inode->i_mtime;
+ aux.size = inode->i_size;
+
+ memcpy(buffer, &aux, sizeof(aux));
+
+ return sizeof(aux);
+}
+
+static void ceph_fscache_inode_get_attr(const void *cookie_netfs_data,
+ uint64_t *size)
+{
+ const struct ceph_inode_info* ci = cookie_netfs_data;
+ const struct inode* inode = &ci->vfs_inode;
+
+ *size = inode->i_size;
+}
+
+static enum fscache_checkaux ceph_fscache_inode_check_aux(
+ void *cookie_netfs_data, const void *data, uint16_t dlen)
+{
+ struct ceph_aux_inode aux;
+ struct ceph_inode_info* ci = cookie_netfs_data;
+ struct inode* inode = &ci->vfs_inode;
+
+ if (dlen != sizeof(aux))
+ return FSCACHE_CHECKAUX_OBSOLETE;
+
+ memset(&aux, 0, sizeof(aux));
+ aux.mtime = inode->i_mtime;
+ aux.size = inode->i_size;
+
+ if (memcmp(data, &aux, sizeof(aux)) != 0)
+ return FSCACHE_CHECKAUX_OBSOLETE;
+
+ dout("ceph inode 0x%p cached okay", ci);
+ return FSCACHE_CHECKAUX_OKAY;
+}
+
+static void ceph_fscache_inode_now_uncached(void* cookie_netfs_data)
+{
+ struct ceph_inode_info* ci = cookie_netfs_data;
+ struct pagevec pvec;
+ pgoff_t first;
+ int loop, nr_pages;
+
+ pagevec_init(&pvec, 0);
+ first = 0;
+
+ dout("ceph inode 0x%p now uncached", ci);
+
+ while (1) {
+ nr_pages = pagevec_lookup(&pvec, ci->vfs_inode.i_mapping, first,
+ PAGEVEC_SIZE - pagevec_count(&pvec));
+
+ if (!nr_pages)
+ break;
+
+ for (loop = 0; loop < nr_pages; loop++)
+ ClearPageFsCache(pvec.pages[loop]);
+
+ first = pvec.pages[nr_pages - 1]->index + 1;
+
+ pvec.nr = nr_pages;
+ pagevec_release(&pvec);
+ cond_resched();
+ }
+}
+
+static const struct fscache_cookie_def ceph_fscache_inode_object_def = {
+ .name = "CEPH.inode",
+ .type = FSCACHE_COOKIE_TYPE_DATAFILE,
+ .get_key = ceph_fscache_inode_get_key,
+ .get_attr = ceph_fscache_inode_get_attr,
+ .get_aux = ceph_fscache_inode_get_aux,
+ .check_aux = ceph_fscache_inode_check_aux,
+ .now_uncached = ceph_fscache_inode_now_uncached,
+};
+
+void ceph_fscache_register_inode_cookie(struct ceph_fs_client* fsc,
+ struct ceph_inode_info* ci)
+{
+ struct inode* inode = &ci->vfs_inode;
+
+ /* No caching for filesystem */
+ if (fsc->fscache == NULL)
+ return;
+
+ /* Only cache for regular files that are read only */
+ if ((ci->vfs_inode.i_mode & S_IFREG) == 0)
+ return;
+
+ /* Avoid multiple racing open requests */
+ mutex_lock(&inode->i_mutex);
+
+ if (ci->fscache)
+ goto done;
+
+ ci->fscache = fscache_acquire_cookie(fsc->fscache,
+ &ceph_fscache_inode_object_def,
+ ci, true);
+ fscache_check_consistency(ci->fscache);
+done:
+ mutex_unlock(&inode->i_mutex);
+
+}
+
+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, 0);
+}
+
+static void ceph_vfs_readpage_complete(struct page *page, void *data, int error)
+{
+ if (!error)
+ SetPageUptodate(page);
+}
+
+static void ceph_vfs_readpage_complete_unlock(struct page *page, void *data, int error)
+{
+ if (!error)
+ SetPageUptodate(page);
+
+ unlock_page(page);
+}
+
+static inline int cache_valid(struct ceph_inode_info *ci)
+{
+ return ((ceph_caps_issued(ci) & CEPH_CAP_FILE_CACHE) &&
+ (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_vfs_readpage_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_vfs_readpage_complete_unlock,
+ 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, 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 (fsc->revalidate_wq)
+ destroy_workqueue(fsc->revalidate_wq);
+
+ fscache_relinquish_cookie(fsc->fscache, 0);
+ fsc->fscache = NULL;
+}
+
+static void ceph_revalidate_work(struct work_struct *work)
+{
+ int issued;
+ u32 orig_gen;
+ struct ceph_inode_info *ci = container_of(work, struct ceph_inode_info,
+ i_revalidate_work);
+ struct inode *inode = &ci->vfs_inode;
+
+ spin_lock(&ci->i_ceph_lock);
+ issued = __ceph_caps_issued(ci, NULL);
+ orig_gen = ci->i_rdcache_gen;
+ spin_unlock(&ci->i_ceph_lock);
+
+ if (!(issued & CEPH_CAP_FILE_CACHE)) {
+ dout("revalidate_work lost cache before validation %p\n",
+ inode);
+ goto out;
+ }
+
+ if (!fscache_check_consistency(ci->fscache))
+ fscache_invalidate(ci->fscache);
+
+ spin_lock(&ci->i_ceph_lock);
+ /* Update the new valid generation (backwards sanity check too) */
+ if (orig_gen > ci->i_fscache_gen) {
+ ci->i_fscache_gen = orig_gen;
+ }
+ spin_unlock(&ci->i_ceph_lock);
+
+out:
+ iput(&ci->vfs_inode);
+}
+
+void ceph_queue_revalidate(struct inode *inode)
+{
+ struct ceph_fs_client *fsc = ceph_sb_to_client(inode->i_sb);
+ struct ceph_inode_info *ci = ceph_inode(inode);
+
+ if (fsc->revalidate_wq == NULL || ci->fscache == NULL)
+ return;
+
+ ihold(inode);
+
+ if (queue_work(ceph_sb_to_client(inode->i_sb)->revalidate_wq,
+ &ci->i_revalidate_work)) {
+ dout("ceph_queue_revalidate %p\n", inode);
+ } else {
+ dout("ceph_queue_revalidate %p failed\n)", inode);
+ iput(inode);
+ }
+}
+
+void ceph_fscache_inode_init(struct ceph_inode_info *ci)
+{
+ ci->fscache = NULL;
+ /* The first load is verifed cookie open time */
+ ci->i_fscache_gen = 1;
+ INIT_WORK(&ci->i_revalidate_work, ceph_revalidate_work);
+}
Code Review / kvmfornfv.git / blobdiff