| /* |
| * 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 + snapshot) */ |
| 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 = i_size_read(inode); |
| |
| 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; |
| *size = i_size_read(&ci->vfs_inode); |
| } |
| |
| 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 = i_size_read(inode); |
| |
| 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 */ |
| inode_lock(inode); |
| |
| 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: |
| 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, 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 bool 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); |
| } |