diff options
Diffstat (limited to 'fs/smb/client/fscache.c')
-rw-r--r-- | fs/smb/client/fscache.c | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/fs/smb/client/fscache.c b/fs/smb/client/fscache.c new file mode 100644 index 0000000000..e5cad149f5 --- /dev/null +++ b/fs/smb/client/fscache.c @@ -0,0 +1,247 @@ +// SPDX-License-Identifier: LGPL-2.1 +/* + * CIFS filesystem cache interface + * + * Copyright (c) 2010 Novell, Inc. + * Author(s): Suresh Jayaraman <sjayaraman@suse.de> + * + */ +#include "fscache.h" +#include "cifsglob.h" +#include "cifs_debug.h" +#include "cifs_fs_sb.h" +#include "cifsproto.h" + +static void cifs_fscache_fill_volume_coherency( + struct cifs_tcon *tcon, + struct cifs_fscache_volume_coherency_data *cd) +{ + memset(cd, 0, sizeof(*cd)); + cd->resource_id = cpu_to_le64(tcon->resource_id); + cd->vol_create_time = tcon->vol_create_time; + cd->vol_serial_number = cpu_to_le32(tcon->vol_serial_number); +} + +int cifs_fscache_get_super_cookie(struct cifs_tcon *tcon) +{ + struct cifs_fscache_volume_coherency_data cd; + struct TCP_Server_Info *server = tcon->ses->server; + struct fscache_volume *vcookie; + const struct sockaddr *sa = (struct sockaddr *)&server->dstaddr; + size_t slen, i; + char *sharename; + char *key; + int ret = -ENOMEM; + + tcon->fscache = NULL; + switch (sa->sa_family) { + case AF_INET: + case AF_INET6: + break; + default: + cifs_dbg(VFS, "Unknown network family '%d'\n", sa->sa_family); + return -EINVAL; + } + + memset(&key, 0, sizeof(key)); + + sharename = extract_sharename(tcon->tree_name); + if (IS_ERR(sharename)) { + cifs_dbg(FYI, "%s: couldn't extract sharename\n", __func__); + return PTR_ERR(sharename); + } + + slen = strlen(sharename); + for (i = 0; i < slen; i++) + if (sharename[i] == '/') + sharename[i] = ';'; + + key = kasprintf(GFP_KERNEL, "cifs,%pISpc,%s", sa, sharename); + if (!key) + goto out; + + cifs_fscache_fill_volume_coherency(tcon, &cd); + vcookie = fscache_acquire_volume(key, + NULL, /* preferred_cache */ + &cd, sizeof(cd)); + cifs_dbg(FYI, "%s: (%s/0x%p)\n", __func__, key, vcookie); + if (IS_ERR(vcookie)) { + if (vcookie != ERR_PTR(-EBUSY)) { + ret = PTR_ERR(vcookie); + goto out_2; + } + pr_err("Cache volume key already in use (%s)\n", key); + vcookie = NULL; + } + + tcon->fscache = vcookie; + ret = 0; +out_2: + kfree(key); +out: + kfree(sharename); + return ret; +} + +void cifs_fscache_release_super_cookie(struct cifs_tcon *tcon) +{ + struct cifs_fscache_volume_coherency_data cd; + + cifs_dbg(FYI, "%s: (0x%p)\n", __func__, tcon->fscache); + + cifs_fscache_fill_volume_coherency(tcon, &cd); + fscache_relinquish_volume(tcon->fscache, &cd, false); + tcon->fscache = NULL; +} + +void cifs_fscache_get_inode_cookie(struct inode *inode) +{ + struct cifs_fscache_inode_coherency_data cd; + struct cifsInodeInfo *cifsi = CIFS_I(inode); + struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb); + struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb); + + cifs_fscache_fill_coherency(&cifsi->netfs.inode, &cd); + + cifsi->netfs.cache = + fscache_acquire_cookie(tcon->fscache, 0, + &cifsi->uniqueid, sizeof(cifsi->uniqueid), + &cd, sizeof(cd), + i_size_read(&cifsi->netfs.inode)); + if (cifsi->netfs.cache) + mapping_set_release_always(inode->i_mapping); +} + +void cifs_fscache_unuse_inode_cookie(struct inode *inode, bool update) +{ + if (update) { + struct cifs_fscache_inode_coherency_data cd; + loff_t i_size = i_size_read(inode); + + cifs_fscache_fill_coherency(inode, &cd); + fscache_unuse_cookie(cifs_inode_cookie(inode), &cd, &i_size); + } else { + fscache_unuse_cookie(cifs_inode_cookie(inode), NULL, NULL); + } +} + +void cifs_fscache_release_inode_cookie(struct inode *inode) +{ + struct cifsInodeInfo *cifsi = CIFS_I(inode); + struct fscache_cookie *cookie = cifs_inode_cookie(inode); + + if (cookie) { + cifs_dbg(FYI, "%s: (0x%p)\n", __func__, cookie); + fscache_relinquish_cookie(cookie, false); + cifsi->netfs.cache = NULL; + } +} + +/* + * Fallback page reading interface. + */ +static int fscache_fallback_read_page(struct inode *inode, struct page *page) +{ + struct netfs_cache_resources cres; + struct fscache_cookie *cookie = cifs_inode_cookie(inode); + struct iov_iter iter; + struct bio_vec bvec; + int ret; + + memset(&cres, 0, sizeof(cres)); + bvec_set_page(&bvec, page, PAGE_SIZE, 0); + iov_iter_bvec(&iter, ITER_DEST, &bvec, 1, PAGE_SIZE); + + ret = fscache_begin_read_operation(&cres, cookie); + if (ret < 0) + return ret; + + ret = fscache_read(&cres, page_offset(page), &iter, NETFS_READ_HOLE_FAIL, + NULL, NULL); + fscache_end_operation(&cres); + return ret; +} + +/* + * Fallback page writing interface. + */ +static int fscache_fallback_write_pages(struct inode *inode, loff_t start, size_t len, + bool no_space_allocated_yet) +{ + struct netfs_cache_resources cres; + struct fscache_cookie *cookie = cifs_inode_cookie(inode); + struct iov_iter iter; + int ret; + + memset(&cres, 0, sizeof(cres)); + iov_iter_xarray(&iter, ITER_SOURCE, &inode->i_mapping->i_pages, start, len); + + ret = fscache_begin_write_operation(&cres, cookie); + if (ret < 0) + return ret; + + ret = cres.ops->prepare_write(&cres, &start, &len, i_size_read(inode), + no_space_allocated_yet); + if (ret == 0) + ret = fscache_write(&cres, start, &iter, NULL, NULL); + fscache_end_operation(&cres); + return ret; +} + +/* + * Retrieve a page from FS-Cache + */ +int __cifs_readpage_from_fscache(struct inode *inode, struct page *page) +{ + int ret; + + cifs_dbg(FYI, "%s: (fsc:%p, p:%p, i:0x%p\n", + __func__, cifs_inode_cookie(inode), page, inode); + + ret = fscache_fallback_read_page(inode, page); + if (ret < 0) + return ret; + + /* Read completed synchronously */ + SetPageUptodate(page); + return 0; +} + +void __cifs_readahead_to_fscache(struct inode *inode, loff_t pos, size_t len) +{ + cifs_dbg(FYI, "%s: (fsc: %p, p: %llx, l: %zx, i: %p)\n", + __func__, cifs_inode_cookie(inode), pos, len, inode); + + fscache_fallback_write_pages(inode, pos, len, true); +} + +/* + * Query the cache occupancy. + */ +int __cifs_fscache_query_occupancy(struct inode *inode, + pgoff_t first, unsigned int nr_pages, + pgoff_t *_data_first, + unsigned int *_data_nr_pages) +{ + struct netfs_cache_resources cres; + struct fscache_cookie *cookie = cifs_inode_cookie(inode); + loff_t start, data_start; + size_t len, data_len; + int ret; + + ret = fscache_begin_read_operation(&cres, cookie); + if (ret < 0) + return ret; + + start = first * PAGE_SIZE; + len = nr_pages * PAGE_SIZE; + ret = cres.ops->query_occupancy(&cres, start, len, PAGE_SIZE, + &data_start, &data_len); + if (ret == 0) { + *_data_first = data_start / PAGE_SIZE; + *_data_nr_pages = len / PAGE_SIZE; + } + + fscache_end_operation(&cres); + return ret; +} |