From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- fs/nfs/fscache.c | 393 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 393 insertions(+) create mode 100644 fs/nfs/fscache.c (limited to 'fs/nfs/fscache.c') diff --git a/fs/nfs/fscache.c b/fs/nfs/fscache.c new file mode 100644 index 0000000000..b05717fe0d --- /dev/null +++ b/fs/nfs/fscache.c @@ -0,0 +1,393 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* NFS filesystem cache interface + * + * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "internal.h" +#include "iostat.h" +#include "fscache.h" +#include "nfstrace.h" + +#define NFS_MAX_KEY_LEN 1000 + +static bool nfs_append_int(char *key, int *_len, unsigned long long x) +{ + if (*_len > NFS_MAX_KEY_LEN) + return false; + if (x == 0) + key[(*_len)++] = ','; + else + *_len += sprintf(key + *_len, ",%llx", x); + return true; +} + +/* + * Get the per-client index cookie for an NFS client if the appropriate mount + * flag was set + * - We always try and get an index cookie for the client, but get filehandle + * cookies on a per-superblock basis, depending on the mount flags + */ +static bool nfs_fscache_get_client_key(struct nfs_client *clp, + char *key, int *_len) +{ + const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) &clp->cl_addr; + const struct sockaddr_in *sin = (struct sockaddr_in *) &clp->cl_addr; + + *_len += snprintf(key + *_len, NFS_MAX_KEY_LEN - *_len, + ",%u.%u,%x", + clp->rpc_ops->version, + clp->cl_minorversion, + clp->cl_addr.ss_family); + + switch (clp->cl_addr.ss_family) { + case AF_INET: + if (!nfs_append_int(key, _len, sin->sin_port) || + !nfs_append_int(key, _len, sin->sin_addr.s_addr)) + return false; + return true; + + case AF_INET6: + if (!nfs_append_int(key, _len, sin6->sin6_port) || + !nfs_append_int(key, _len, sin6->sin6_addr.s6_addr32[0]) || + !nfs_append_int(key, _len, sin6->sin6_addr.s6_addr32[1]) || + !nfs_append_int(key, _len, sin6->sin6_addr.s6_addr32[2]) || + !nfs_append_int(key, _len, sin6->sin6_addr.s6_addr32[3])) + return false; + return true; + + default: + printk(KERN_WARNING "NFS: Unknown network family '%d'\n", + clp->cl_addr.ss_family); + return false; + } +} + +/* + * Get the cache cookie for an NFS superblock. + * + * The default uniquifier is just an empty string, but it may be overridden + * either by the 'fsc=xxx' option to mount, or by inheriting it from the parent + * superblock across an automount point of some nature. + */ +int nfs_fscache_get_super_cookie(struct super_block *sb, const char *uniq, int ulen) +{ + struct fscache_volume *vcookie; + struct nfs_server *nfss = NFS_SB(sb); + unsigned int len = 3; + char *key; + + if (uniq) { + nfss->fscache_uniq = kmemdup_nul(uniq, ulen, GFP_KERNEL); + if (!nfss->fscache_uniq) + return -ENOMEM; + } + + key = kmalloc(NFS_MAX_KEY_LEN + 24, GFP_KERNEL); + if (!key) + return -ENOMEM; + + memcpy(key, "nfs", 3); + if (!nfs_fscache_get_client_key(nfss->nfs_client, key, &len) || + !nfs_append_int(key, &len, nfss->fsid.major) || + !nfs_append_int(key, &len, nfss->fsid.minor) || + !nfs_append_int(key, &len, sb->s_flags & NFS_SB_MASK) || + !nfs_append_int(key, &len, nfss->flags) || + !nfs_append_int(key, &len, nfss->rsize) || + !nfs_append_int(key, &len, nfss->wsize) || + !nfs_append_int(key, &len, nfss->acregmin) || + !nfs_append_int(key, &len, nfss->acregmax) || + !nfs_append_int(key, &len, nfss->acdirmin) || + !nfs_append_int(key, &len, nfss->acdirmax) || + !nfs_append_int(key, &len, nfss->client->cl_auth->au_flavor)) + goto out; + + if (ulen > 0) { + if (ulen > NFS_MAX_KEY_LEN - len) + goto out; + key[len++] = ','; + memcpy(key + len, uniq, ulen); + len += ulen; + } + key[len] = 0; + + /* create a cache index for looking up filehandles */ + vcookie = fscache_acquire_volume(key, + NULL, /* preferred_cache */ + NULL, 0 /* coherency_data */); + if (IS_ERR(vcookie)) { + if (vcookie != ERR_PTR(-EBUSY)) { + kfree(key); + return PTR_ERR(vcookie); + } + pr_err("NFS: Cache volume key already in use (%s)\n", key); + vcookie = NULL; + } + nfss->fscache = vcookie; + +out: + kfree(key); + return 0; +} + +/* + * release a per-superblock cookie + */ +void nfs_fscache_release_super_cookie(struct super_block *sb) +{ + struct nfs_server *nfss = NFS_SB(sb); + + fscache_relinquish_volume(nfss->fscache, NULL, false); + nfss->fscache = NULL; + kfree(nfss->fscache_uniq); +} + +/* + * Initialise the per-inode cache cookie pointer for an NFS inode. + */ +void nfs_fscache_init_inode(struct inode *inode) +{ + struct nfs_fscache_inode_auxdata auxdata; + struct nfs_server *nfss = NFS_SERVER(inode); + struct nfs_inode *nfsi = NFS_I(inode); + + netfs_inode(inode)->cache = NULL; + if (!(nfss->fscache && S_ISREG(inode->i_mode))) + return; + + nfs_fscache_update_auxdata(&auxdata, inode); + + netfs_inode(inode)->cache = fscache_acquire_cookie( + nfss->fscache, + 0, + nfsi->fh.data, /* index_key */ + nfsi->fh.size, + &auxdata, /* aux_data */ + sizeof(auxdata), + i_size_read(inode)); + + if (netfs_inode(inode)->cache) + mapping_set_release_always(inode->i_mapping); +} + +/* + * Release a per-inode cookie. + */ +void nfs_fscache_clear_inode(struct inode *inode) +{ + fscache_relinquish_cookie(netfs_i_cookie(netfs_inode(inode)), false); + netfs_inode(inode)->cache = NULL; +} + +/* + * Enable or disable caching for a file that is being opened as appropriate. + * The cookie is allocated when the inode is initialised, but is not enabled at + * that time. Enablement is deferred to file-open time to avoid stat() and + * access() thrashing the cache. + * + * For now, with NFS, only regular files that are open read-only will be able + * to use the cache. + * + * We enable the cache for an inode if we open it read-only and it isn't + * currently open for writing. We disable the cache if the inode is open + * write-only. + * + * The caller uses the file struct to pin i_writecount on the inode before + * calling us when a file is opened for writing, so we can make use of that. + * + * Note that this may be invoked multiple times in parallel by parallel + * nfs_open() functions. + */ +void nfs_fscache_open_file(struct inode *inode, struct file *filp) +{ + struct nfs_fscache_inode_auxdata auxdata; + struct fscache_cookie *cookie = netfs_i_cookie(netfs_inode(inode)); + bool open_for_write = inode_is_open_for_write(inode); + + if (!fscache_cookie_valid(cookie)) + return; + + fscache_use_cookie(cookie, open_for_write); + if (open_for_write) { + nfs_fscache_update_auxdata(&auxdata, inode); + fscache_invalidate(cookie, &auxdata, i_size_read(inode), + FSCACHE_INVAL_DIO_WRITE); + } +} +EXPORT_SYMBOL_GPL(nfs_fscache_open_file); + +void nfs_fscache_release_file(struct inode *inode, struct file *filp) +{ + struct nfs_fscache_inode_auxdata auxdata; + struct fscache_cookie *cookie = netfs_i_cookie(netfs_inode(inode)); + loff_t i_size = i_size_read(inode); + + nfs_fscache_update_auxdata(&auxdata, inode); + fscache_unuse_cookie(cookie, &auxdata, &i_size); +} + +int nfs_netfs_read_folio(struct file *file, struct folio *folio) +{ + if (!netfs_inode(folio_inode(folio))->cache) + return -ENOBUFS; + + return netfs_read_folio(file, folio); +} + +int nfs_netfs_readahead(struct readahead_control *ractl) +{ + struct inode *inode = ractl->mapping->host; + + if (!netfs_inode(inode)->cache) + return -ENOBUFS; + + netfs_readahead(ractl); + return 0; +} + +static atomic_t nfs_netfs_debug_id; +static int nfs_netfs_init_request(struct netfs_io_request *rreq, struct file *file) +{ + rreq->netfs_priv = get_nfs_open_context(nfs_file_open_context(file)); + rreq->debug_id = atomic_inc_return(&nfs_netfs_debug_id); + + return 0; +} + +static void nfs_netfs_free_request(struct netfs_io_request *rreq) +{ + put_nfs_open_context(rreq->netfs_priv); +} + +static inline int nfs_netfs_begin_cache_operation(struct netfs_io_request *rreq) +{ + return fscache_begin_read_operation(&rreq->cache_resources, + netfs_i_cookie(netfs_inode(rreq->inode))); +} + +static struct nfs_netfs_io_data *nfs_netfs_alloc(struct netfs_io_subrequest *sreq) +{ + struct nfs_netfs_io_data *netfs; + + netfs = kzalloc(sizeof(*netfs), GFP_KERNEL_ACCOUNT); + if (!netfs) + return NULL; + netfs->sreq = sreq; + refcount_set(&netfs->refcount, 1); + return netfs; +} + +static bool nfs_netfs_clamp_length(struct netfs_io_subrequest *sreq) +{ + size_t rsize = NFS_SB(sreq->rreq->inode->i_sb)->rsize; + + sreq->len = min(sreq->len, rsize); + return true; +} + +static void nfs_netfs_issue_read(struct netfs_io_subrequest *sreq) +{ + struct nfs_netfs_io_data *netfs; + struct nfs_pageio_descriptor pgio; + struct inode *inode = sreq->rreq->inode; + struct nfs_open_context *ctx = sreq->rreq->netfs_priv; + struct page *page; + int err; + pgoff_t start = (sreq->start + sreq->transferred) >> PAGE_SHIFT; + pgoff_t last = ((sreq->start + sreq->len - + sreq->transferred - 1) >> PAGE_SHIFT); + XA_STATE(xas, &sreq->rreq->mapping->i_pages, start); + + nfs_pageio_init_read(&pgio, inode, false, + &nfs_async_read_completion_ops); + + netfs = nfs_netfs_alloc(sreq); + if (!netfs) + return netfs_subreq_terminated(sreq, -ENOMEM, false); + + pgio.pg_netfs = netfs; /* used in completion */ + + xas_lock(&xas); + xas_for_each(&xas, page, last) { + /* nfs_read_add_folio() may schedule() due to pNFS layout and other RPCs */ + xas_pause(&xas); + xas_unlock(&xas); + err = nfs_read_add_folio(&pgio, ctx, page_folio(page)); + if (err < 0) { + netfs->error = err; + goto out; + } + xas_lock(&xas); + } + xas_unlock(&xas); +out: + nfs_pageio_complete_read(&pgio); + nfs_netfs_put(netfs); +} + +void nfs_netfs_initiate_read(struct nfs_pgio_header *hdr) +{ + struct nfs_netfs_io_data *netfs = hdr->netfs; + + if (!netfs) + return; + + nfs_netfs_get(netfs); +} + +int nfs_netfs_folio_unlock(struct folio *folio) +{ + struct inode *inode = folio_file_mapping(folio)->host; + + /* + * If fscache is enabled, netfs will unlock pages. + */ + if (netfs_inode(inode)->cache) + return 0; + + return 1; +} + +void nfs_netfs_read_completion(struct nfs_pgio_header *hdr) +{ + struct nfs_netfs_io_data *netfs = hdr->netfs; + struct netfs_io_subrequest *sreq; + + if (!netfs) + return; + + sreq = netfs->sreq; + if (test_bit(NFS_IOHDR_EOF, &hdr->flags)) + __set_bit(NETFS_SREQ_CLEAR_TAIL, &sreq->flags); + + if (hdr->error) + netfs->error = hdr->error; + else + atomic64_add(hdr->res.count, &netfs->transferred); + + nfs_netfs_put(netfs); + hdr->netfs = NULL; +} + +const struct netfs_request_ops nfs_netfs_ops = { + .init_request = nfs_netfs_init_request, + .free_request = nfs_netfs_free_request, + .begin_cache_operation = nfs_netfs_begin_cache_operation, + .issue_read = nfs_netfs_issue_read, + .clamp_length = nfs_netfs_clamp_length +}; -- cgit v1.2.3