NFSv4: client-side caching NFSv4 ACLs Add nfs4_acl field to the nfs_inode, and use it to cache acls. Only cache acls of size up to a page. Also prepare for up to a page of acl data even when the user doesn't pass in a buffer, as when they want to get the acl length to decide what size buffer to allocate. Signed-off-by: J. Bruce Fields Signed-off-by: Trond Myklebust --- fs/nfs/inode.c | 7 +- fs/nfs/nfs4proc.c | 129 +++++++++++++++++++++++++++++++++++++++++++++---- include/linux/nfs_fs.h | 2 3 files changed, 124 insertions(+), 14 deletions(-) Index: linux-2.6.12-rc1/fs/nfs/inode.c =================================================================== --- linux-2.6.12-rc1.orig/fs/nfs/inode.c +++ linux-2.6.12-rc1/fs/nfs/inode.c @@ -142,10 +142,6 @@ nfs_delete_inode(struct inode * inode) clear_inode(inode); } -/* - * For the moment, the only task for the NFS clear_inode method is to - * release the mmap credential - */ static void nfs_clear_inode(struct inode *inode) { @@ -1923,6 +1919,9 @@ static struct inode *nfs_alloc_inode(str if (!nfsi) return NULL; nfsi->flags = 0; +#ifdef CONFIG_NFS_V4 + nfsi->nfs4_acl = NULL; +#endif /* CONFIG_NFS_V4 */ return &nfsi->vfs_inode; } Index: linux-2.6.12-rc1/fs/nfs/nfs4proc.c =================================================================== --- linux-2.6.12-rc1.orig/fs/nfs/nfs4proc.c +++ linux-2.6.12-rc1/fs/nfs/nfs4proc.c @@ -2188,9 +2188,75 @@ static void buf_to_pages(const void *buf } } -static ssize_t nfs4_proc_get_acl(struct inode *inode, void *buf, size_t buflen) +struct nfs4_cached_acl { + int cached; + size_t len; + char data[]; +}; + +static void nfs4_set_cached_acl(struct inode *inode, struct nfs4_cached_acl *acl) +{ + struct nfs_inode *nfsi = NFS_I(inode); + + spin_lock(&inode->i_lock); + kfree(nfsi->nfs4_acl); + nfsi->nfs4_acl = acl; + spin_unlock(&inode->i_lock); +} + +static void nfs4_zap_acl_attr(struct inode *inode) +{ + nfs4_set_cached_acl(inode, NULL); +} + +static inline ssize_t nfs4_read_cached_acl(struct inode *inode, char *buf, size_t buflen) +{ + struct nfs_inode *nfsi = NFS_I(inode); + struct nfs4_cached_acl *acl; + int ret = -ENOENT; + + spin_lock(&inode->i_lock); + acl = nfsi->nfs4_acl; + if (acl == NULL) + goto out; + if (buf == NULL) /* user is just asking for length */ + goto out_len; + if (acl->cached == 0) + goto out; + ret = -ERANGE; /* see getxattr(2) man page */ + if (acl->len > buflen) + goto out; + memcpy(buf, acl->data, acl->len); +out_len: + ret = acl->len; +out: + spin_unlock(&inode->i_lock); + return ret; +} + +static void nfs4_write_cached_acl(struct inode *inode, const char *buf, size_t acl_len) +{ + struct nfs4_cached_acl *acl; + + if (buf && acl_len <= PAGE_SIZE) { + acl = kmalloc(sizeof(*acl) + acl_len, GFP_KERNEL); + if (acl == NULL) + goto out; + acl->cached = 1; + memcpy(acl->data, buf, acl_len); + } else { + acl = kmalloc(sizeof(*acl), GFP_KERNEL); + if (acl == NULL) + goto out; + acl->cached = 0; + } + acl->len = acl_len; +out: + nfs4_set_cached_acl(inode, acl); +} + +static inline ssize_t nfs4_get_acl_uncached(struct inode *inode, void *buf, size_t buflen) { - struct nfs_server *server = NFS_SERVER(inode); struct page *pages[NFS4ACL_MAXPAGES]; struct nfs_getaclargs args = { .fh = NFS_FH(inode), @@ -2198,24 +2264,66 @@ static ssize_t nfs4_proc_get_acl(struct .acl_len = buflen, }; size_t resp_len = buflen; + void *resp_buf; struct rpc_message msg = { .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_GETACL], .rpc_argp = &args, .rpc_resp = &resp_len, }; + struct page *localpage = NULL; int ret; - if (!nfs4_server_supports_acls(server)) - return -EOPNOTSUPP; - buf_to_pages(buf, buflen, args.acl_pages, &args.acl_pgbase); + if (buflen < PAGE_SIZE) { + /* As long as we're doing a round trip to the server anyway, + * let's be prepared for a page of acl data. */ + localpage = alloc_page(GFP_KERNEL); + resp_buf = page_address(localpage); + if (localpage == NULL) + return -ENOMEM; + args.acl_pages[0] = localpage; + args.acl_pgbase = 0; + args.acl_len = PAGE_SIZE; + } else { + resp_buf = buf; + buf_to_pages(buf, buflen, args.acl_pages, &args.acl_pgbase); + } ret = rpc_call_sync(NFS_CLIENT(inode), &msg, 0); - if (buflen && resp_len > buflen) - return -ERANGE; - if (ret == 0) - ret = resp_len; + if (ret) + goto out_free; + if (resp_len > args.acl_len) + nfs4_write_cached_acl(inode, NULL, resp_len); + else + nfs4_write_cached_acl(inode, resp_buf, resp_len); + if (buf) { + ret = -ERANGE; + if (resp_len > buflen) + goto out_free; + if (localpage) + memcpy(buf, resp_buf, resp_len); + } + ret = resp_len; +out_free: + if (localpage) + __free_page(localpage); return ret; } +static ssize_t nfs4_proc_get_acl(struct inode *inode, void *buf, size_t buflen) +{ + struct nfs_server *server = NFS_SERVER(inode); + int ret; + + if (!nfs4_server_supports_acls(server)) + return -EOPNOTSUPP; + ret = nfs_revalidate_inode(server, inode); + if (ret < 0) + return ret; + ret = nfs4_read_cached_acl(inode, buf, buflen); + if (ret != -ENOENT) + return ret; + return nfs4_get_acl_uncached(inode, buf, buflen); +} + static int nfs4_proc_set_acl(struct inode *inode, const void *buf, size_t buflen) { struct nfs_server *server = NFS_SERVER(inode); @@ -2236,6 +2344,8 @@ static int nfs4_proc_set_acl(struct inod return -EOPNOTSUPP; buf_to_pages(buf, buflen, arg.acl_pages, &arg.acl_pgbase); ret = rpc_call_sync(NFS_SERVER(inode)->client, &msg, 0); + if (ret == 0) + nfs4_write_cached_acl(inode, buf, buflen); return ret; } @@ -2907,6 +3017,7 @@ struct nfs_rpc_ops nfs_v4_clientops = { .file_open = nfs4_proc_file_open, .file_release = nfs4_proc_file_release, .lock = nfs4_proc_lock, + .clear_acl_cache = nfs4_zap_acl_attr, }; /* Index: linux-2.6.12-rc1/include/linux/nfs_fs.h =================================================================== --- linux-2.6.12-rc1.orig/include/linux/nfs_fs.h +++ linux-2.6.12-rc1/include/linux/nfs_fs.h @@ -169,13 +169,13 @@ struct nfs_inode { wait_queue_head_t nfs_i_wait; #ifdef CONFIG_NFS_V4 + struct nfs4_cached_acl *nfs4_acl; /* NFSv4 state */ struct list_head open_states; struct nfs_delegation *delegation; int delegation_state; struct rw_semaphore rwsem; #endif /* CONFIG_NFS_V4*/ - struct inode vfs_inode; };