diff options
Diffstat (limited to 'fs/ceph/cache.c')
| -rw-r--r-- | fs/ceph/cache.c | 393 |
1 files changed, 393 insertions, 0 deletions
diff --git a/fs/ceph/cache.c b/fs/ceph/cache.c new file mode 100644 index 000000000000..5c413ecf1f15 --- /dev/null +++ b/fs/ceph/cache.c @@ -0,0 +1,393 @@ +/* + * 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 <linux/fscache.h> + +#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() +{ + return fscache_register_netfs(&ceph_cache_netfs); +} + +void ceph_fscache_unregister() +{ + 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); + + 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); +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 (!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); + + 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_inode_info *ci = ceph_inode(inode); + + 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); +} |