diff options
Diffstat (limited to 'fs/cifs/dfs_cache.c')
| -rw-r--r-- | fs/cifs/dfs_cache.c | 1367 |
1 files changed, 1367 insertions, 0 deletions
diff --git a/fs/cifs/dfs_cache.c b/fs/cifs/dfs_cache.c new file mode 100644 index 000000000000..cd63c4a70875 --- /dev/null +++ b/fs/cifs/dfs_cache.c @@ -0,0 +1,1367 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * DFS referral cache routines + * + * Copyright (c) 2018 Paulo Alcantara <palcantara@suse.de> + */ + +#include <linux/rcupdate.h> +#include <linux/rculist.h> +#include <linux/jhash.h> +#include <linux/ktime.h> +#include <linux/slab.h> +#include <linux/nls.h> +#include <linux/workqueue.h> +#include "cifsglob.h" +#include "smb2pdu.h" +#include "smb2proto.h" +#include "cifsproto.h" +#include "cifs_debug.h" +#include "cifs_unicode.h" +#include "smb2glob.h" + +#include "dfs_cache.h" + +#define DFS_CACHE_HTABLE_SIZE 32 +#define DFS_CACHE_MAX_ENTRIES 64 + +#define IS_INTERLINK_SET(v) ((v) & (DFSREF_REFERRAL_SERVER | \ + DFSREF_STORAGE_SERVER)) + +struct dfs_cache_tgt { + char *t_name; + struct list_head t_list; +}; + +struct dfs_cache_entry { + struct hlist_node ce_hlist; + const char *ce_path; + int ce_ttl; + int ce_srvtype; + int ce_flags; + struct timespec64 ce_etime; + int ce_path_consumed; + int ce_numtgts; + struct list_head ce_tlist; + struct dfs_cache_tgt *ce_tgthint; + struct rcu_head ce_rcu; +}; + +static struct kmem_cache *dfs_cache_slab __read_mostly; + +struct dfs_cache_vol_info { + char *vi_fullpath; + struct smb_vol vi_vol; + struct list_head vi_list; +}; + +struct dfs_cache { + struct mutex dc_lock; + struct nls_table *dc_nlsc; + struct list_head dc_vol_list; + int dc_ttl; + struct delayed_work dc_refresh; +}; + +static struct dfs_cache dfs_cache; + +/* + * Number of entries in the cache + */ +static size_t dfs_cache_count; + +static DEFINE_MUTEX(dfs_cache_list_lock); +static struct hlist_head dfs_cache_htable[DFS_CACHE_HTABLE_SIZE]; + +static void refresh_cache_worker(struct work_struct *work); + +static inline bool is_path_valid(const char *path) +{ + return path && (strchr(path + 1, '\\') || strchr(path + 1, '/')); +} + +static inline int get_normalized_path(const char *path, char **npath) +{ + if (*path == '\\') { + *npath = (char *)path; + } else { + *npath = kstrndup(path, strlen(path), GFP_KERNEL); + if (!*npath) + return -ENOMEM; + convert_delimiter(*npath, '\\'); + } + return 0; +} + +static inline void free_normalized_path(const char *path, char *npath) +{ + if (path != npath) + kfree(npath); +} + +static inline bool cache_entry_expired(const struct dfs_cache_entry *ce) +{ + struct timespec64 ts; + + ktime_get_coarse_real_ts64(&ts); + return timespec64_compare(&ts, &ce->ce_etime) >= 0; +} + +static inline void free_tgts(struct dfs_cache_entry *ce) +{ + struct dfs_cache_tgt *t, *n; + + list_for_each_entry_safe(t, n, &ce->ce_tlist, t_list) { + list_del(&t->t_list); + kfree(t->t_name); + kfree(t); + } +} + +static void free_cache_entry(struct rcu_head *rcu) +{ + struct dfs_cache_entry *ce = container_of(rcu, struct dfs_cache_entry, + ce_rcu); + kmem_cache_free(dfs_cache_slab, ce); +} + +static inline void flush_cache_ent(struct dfs_cache_entry *ce) +{ + if (hlist_unhashed(&ce->ce_hlist)) + return; + + hlist_del_init_rcu(&ce->ce_hlist); + kfree(ce->ce_path); + free_tgts(ce); + dfs_cache_count--; + call_rcu(&ce->ce_rcu, free_cache_entry); +} + +static void flush_cache_ents(void) +{ + int i; + + rcu_read_lock(); + for (i = 0; i < DFS_CACHE_HTABLE_SIZE; i++) { + struct hlist_head *l = &dfs_cache_htable[i]; + struct dfs_cache_entry *ce; + + hlist_for_each_entry_rcu(ce, l, ce_hlist) + flush_cache_ent(ce); + } + rcu_read_unlock(); +} + +/* + * dfs cache /proc file + */ +static int dfscache_proc_show(struct seq_file *m, void *v) +{ + int bucket; + struct dfs_cache_entry *ce; + struct dfs_cache_tgt *t; + + seq_puts(m, "DFS cache\n---------\n"); + + mutex_lock(&dfs_cache_list_lock); + + rcu_read_lock(); + hash_for_each_rcu(dfs_cache_htable, bucket, ce, ce_hlist) { + seq_printf(m, + "cache entry: path=%s,type=%s,ttl=%d,etime=%ld," + "interlink=%s,path_consumed=%d,expired=%s\n", + ce->ce_path, + ce->ce_srvtype == DFS_TYPE_ROOT ? "root" : "link", + ce->ce_ttl, ce->ce_etime.tv_nsec, + IS_INTERLINK_SET(ce->ce_flags) ? "yes" : "no", + ce->ce_path_consumed, + cache_entry_expired(ce) ? "yes" : "no"); + + list_for_each_entry(t, &ce->ce_tlist, t_list) { + seq_printf(m, " %s%s\n", + t->t_name, + ce->ce_tgthint == t ? " (target hint)" : ""); + } + + } + rcu_read_unlock(); + + mutex_unlock(&dfs_cache_list_lock); + return 0; +} + +static ssize_t dfscache_proc_write(struct file *file, const char __user *buffer, + size_t count, loff_t *ppos) +{ + char c; + int rc; + + rc = get_user(c, buffer); + if (rc) + return rc; + + if (c != '0') + return -EINVAL; + + cifs_dbg(FYI, "clearing dfs cache"); + mutex_lock(&dfs_cache_list_lock); + flush_cache_ents(); + mutex_unlock(&dfs_cache_list_lock); + + return count; +} + +static int dfscache_proc_open(struct inode *inode, struct file *file) +{ + return single_open(file, dfscache_proc_show, NULL); +} + +const struct file_operations dfscache_proc_fops = { + .open = dfscache_proc_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, + .write = dfscache_proc_write, +}; + +#ifdef CONFIG_CIFS_DEBUG2 +static inline void dump_tgts(const struct dfs_cache_entry *ce) +{ + struct dfs_cache_tgt *t; + + cifs_dbg(FYI, "target list:\n"); + list_for_each_entry(t, &ce->ce_tlist, t_list) { + cifs_dbg(FYI, " %s%s\n", t->t_name, + ce->ce_tgthint == t ? " (target hint)" : ""); + } +} + +static inline void dump_ce(const struct dfs_cache_entry *ce) +{ + cifs_dbg(FYI, "cache entry: path=%s,type=%s,ttl=%d,etime=%ld," + "interlink=%s,path_consumed=%d,expired=%s\n", ce->ce_path, + ce->ce_srvtype == DFS_TYPE_ROOT ? "root" : "link", ce->ce_ttl, + ce->ce_etime.tv_nsec, + IS_INTERLINK_SET(ce->ce_flags) ? "yes" : "no", + ce->ce_path_consumed, + cache_entry_expired(ce) ? "yes" : "no"); + dump_tgts(ce); +} + +static inline void dump_refs(const struct dfs_info3_param *refs, int numrefs) +{ + int i; + + cifs_dbg(FYI, "DFS referrals returned by the server:\n"); + for (i = 0; i < numrefs; i++) { + const struct dfs_info3_param *ref = &refs[i]; + + cifs_dbg(FYI, + "\n" + "flags: 0x%x\n" + "path_consumed: %d\n" + "server_type: 0x%x\n" + "ref_flag: 0x%x\n" + "path_name: %s\n" + "node_name: %s\n" + "ttl: %d (%dm)\n", + ref->flags, ref->path_consumed, ref->server_type, + ref->ref_flag, ref->path_name, ref->node_name, + ref->ttl, ref->ttl / 60); + } +} +#else +#define dump_tgts(e) +#define dump_ce(e) +#define dump_refs(r, n) +#endif + +/** + * dfs_cache_init - Initialize DFS referral cache. + * + * Return zero if initialized successfully, otherwise non-zero. + */ +int dfs_cache_init(void) +{ + int i; + + dfs_cache_slab = kmem_cache_create("cifs_dfs_cache", + sizeof(struct dfs_cache_entry), 0, + SLAB_HWCACHE_ALIGN, NULL); + if (!dfs_cache_slab) + return -ENOMEM; + + for (i = 0; i < DFS_CACHE_HTABLE_SIZE; i++) + INIT_HLIST_HEAD(&dfs_cache_htable[i]); + + INIT_LIST_HEAD(&dfs_cache.dc_vol_list); + mutex_init(&dfs_cache.dc_lock); + INIT_DELAYED_WORK(&dfs_cache.dc_refresh, refresh_cache_worker); + dfs_cache.dc_ttl = -1; + dfs_cache.dc_nlsc = load_nls_default(); + + cifs_dbg(FYI, "%s: initialized DFS referral cache\n", __func__); + return 0; +} + +static inline unsigned int cache_entry_hash(const void *data, int size) +{ + unsigned int h; + + h = jhash(data, size, 0); + return h & (DFS_CACHE_HTABLE_SIZE - 1); +} + +/* Check whether second path component of @path is SYSVOL or NETLOGON */ +static inline bool is_sysvol_or_netlogon(const char *path) +{ + const char *s; + char sep = path[0]; + + s = strchr(path + 1, sep) + 1; + return !strncasecmp(s, "sysvol", strlen("sysvol")) || + !strncasecmp(s, "netlogon", strlen("netlogon")); +} + +/* Return target hint of a DFS cache entry */ +static inline char *get_tgt_name(const struct dfs_cache_entry *ce) +{ + struct dfs_cache_tgt *t = ce->ce_tgthint; + + return t ? t->t_name : ERR_PTR(-ENOENT); +} + +/* Return expire time out of a new entry's TTL */ +static inline struct timespec64 get_expire_time(int ttl) +{ + struct timespec64 ts = { + .tv_sec = ttl, + .tv_nsec = 0, + }; + struct timespec64 now; + + ktime_get_coarse_real_ts64(&now); + return timespec64_add(now, ts); +} + +/* Allocate a new DFS target */ +static inline struct dfs_cache_tgt *alloc_tgt(const char *name) +{ + struct dfs_cache_tgt *t; + + t = kmalloc(sizeof(*t), GFP_KERNEL); + if (!t) + return ERR_PTR(-ENOMEM); + t->t_name = kstrndup(name, strlen(name), GFP_KERNEL); + if (!t->t_name) { + kfree(t); + return ERR_PTR(-ENOMEM); + } + INIT_LIST_HEAD(&t->t_list); + return t; +} + +/* + * Copy DFS referral information to a cache entry and conditionally update + * target hint. + */ +static int copy_ref_data(const struct dfs_info3_param *refs, int numrefs, + struct dfs_cache_entry *ce, const char *tgthint) +{ + int i; + + ce->ce_ttl = refs[0].ttl; + ce->ce_etime = get_expire_time(ce->ce_ttl); + ce->ce_srvtype = refs[0].server_type; + ce->ce_flags = refs[0].ref_flag; + ce->ce_path_consumed = refs[0].path_consumed; + + for (i = 0; i < numrefs; i++) { + struct dfs_cache_tgt *t; + + t = alloc_tgt(refs[i].node_name); + if (IS_ERR(t)) { + free_tgts(ce); + return PTR_ERR(t); + } + if (tgthint && !strcasecmp(t->t_name, tgthint)) { + list_add(&t->t_list, &ce->ce_tlist); + tgthint = NULL; + } else { + list_add_tail(&t->t_list, &ce->ce_tlist); + } + ce->ce_numtgts++; + } + + ce->ce_tgthint = list_first_entry_or_null(&ce->ce_tlist, + struct dfs_cache_tgt, t_list); + + return 0; +} + +/* Allocate a new cache entry */ +static struct dfs_cache_entry * +alloc_cache_entry(const char *path, const struct dfs_info3_param *refs, + int numrefs) +{ + struct dfs_cache_entry *ce; + int rc; + + ce = kmem_cache_zalloc(dfs_cache_slab, GFP_KERNEL); + if (!ce) + return ERR_PTR(-ENOMEM); + + ce->ce_path = kstrdup_const(path, GFP_KERNEL); + if (!ce->ce_path) { + kmem_cache_free(dfs_cache_slab, ce); + return ERR_PTR(-ENOMEM); + } + INIT_HLIST_NODE(&ce->ce_hlist); + INIT_LIST_HEAD(&ce->ce_tlist); + + rc = copy_ref_data(refs, numrefs, ce, NULL); + if (rc) { + kfree(ce->ce_path); + kmem_cache_free(dfs_cache_slab, ce); + ce = ERR_PTR(rc); + } + return ce; +} + +static void remove_oldest_entry(void) +{ + int bucket; + struct dfs_cache_entry *ce; + struct dfs_cache_entry *to_del = NULL; + + rcu_read_lock(); + hash_for_each_rcu(dfs_cache_htable, bucket, ce, ce_hlist) { + if (!to_del || timespec64_compare(&ce->ce_etime, + &to_del->ce_etime) < 0) + to_del = ce; + } + if (!to_del) { + cifs_dbg(FYI, "%s: no entry to remove", __func__); + goto out; + } + cifs_dbg(FYI, "%s: removing entry", __func__); + dump_ce(to_del); + flush_cache_ent(to_del); +out: + rcu_read_unlock(); +} + +/* Add a new DFS cache entry */ +static inline struct dfs_cache_entry * +add_cache_entry(unsigned int hash, const char *path, + const struct dfs_info3_param *refs, int numrefs) +{ + struct dfs_cache_entry *ce; + + ce = alloc_cache_entry(path, refs, numrefs); + if (IS_ERR(ce)) + return ce; + + hlist_add_head_rcu(&ce->ce_hlist, &dfs_cache_htable[hash]); + + mutex_lock(&dfs_cache.dc_lock); + if (dfs_cache.dc_ttl < 0) { + dfs_cache.dc_ttl = ce->ce_ttl; + queue_delayed_work(cifsiod_wq, &dfs_cache.dc_refresh, + dfs_cache.dc_ttl * HZ); + } else { + dfs_cache.dc_ttl = min_t(int, dfs_cache.dc_ttl, ce->ce_ttl); + mod_delayed_work(cifsiod_wq, &dfs_cache.dc_refresh, + dfs_cache.dc_ttl * HZ); + } + mutex_unlock(&dfs_cache.dc_lock); + + return ce; +} + +static struct dfs_cache_entry *__find_cache_entry(unsigned int hash, + const char *path) +{ + struct dfs_cache_entry *ce; + bool found = false; + + rcu_read_lock(); + hlist_for_each_entry_rcu(ce, &dfs_cache_htable[hash], ce_hlist) { + if (!strcasecmp(path, ce->ce_path)) { +#ifdef CONFIG_CIFS_DEBUG2 + char *name = get_tgt_name(ce); + + if (unlikely(IS_ERR(name))) { + rcu_read_unlock(); + return ERR_CAST(name); + } + cifs_dbg(FYI, "%s: cache hit\n", __func__); + cifs_dbg(FYI, "%s: target hint: %s\n", __func__, name); +#endif + found = true; + break; + } + } + rcu_read_unlock(); + return found ? ce : ERR_PTR(-ENOENT); +} + +/* + * Find a DFS cache entry in hash table and optionally check prefix path against + * @path. + * Use whole path components in the match. + * Return ERR_PTR(-ENOENT) if the entry is not found. + */ +static inline struct dfs_cache_entry *find_cache_entry(const char *path, + unsigned int *hash) +{ + *hash = cache_entry_hash(path, strlen(path)); + return __find_cache_entry(*hash, path); +} + +static inline void destroy_slab_cache(void) +{ + rcu_barrier(); + kmem_cache_destroy(dfs_cache_slab); +} + +static inline void free_vol(struct dfs_cache_vol_info *vi) +{ + list_del(&vi->vi_list); + kfree(vi->vi_fullpath); + cifs_cleanup_volume_info_contents(&vi->vi_vol); + kfree(vi); +} + +static inline void free_vol_list(void) +{ + struct dfs_cache_vol_info *vi, *nvi; + + list_for_each_entry_safe(vi, nvi, &dfs_cache.dc_vol_list, vi_list) + free_vol(vi); +} + +/** + * dfs_cache_destroy - destroy DFS referral cache + */ +void dfs_cache_destroy(void) +{ + cancel_delayed_work_sync(&dfs_cache.dc_refresh); + unload_nls(dfs_cache.dc_nlsc); + free_vol_list(); + mutex_destroy(&dfs_cache.dc_lock); + + flush_cache_ents(); + destroy_slab_cache(); + mutex_destroy(&dfs_cache_list_lock); + + cifs_dbg(FYI, "%s: destroyed DFS referral cache\n", __func__); +} + +static inline struct dfs_cache_entry * +__update_cache_entry(const char *path, const struct dfs_info3_param *refs, + int numrefs) +{ + int rc; + unsigned int h; + struct dfs_cache_entry *ce; + char *s, *th = NULL; + + ce = find_cache_entry(path, &h); + if (IS_ERR(ce)) + return ce; + + if (ce->ce_tgthint) { + s = ce->ce_tgthint->t_name; + th = kstrndup(s, strlen(s), GFP_KERNEL); + if (!th) + return ERR_PTR(-ENOMEM); + } + + free_tgts(ce); + ce->ce_numtgts = 0; + + rc = copy_ref_data(refs, numrefs, ce, th); + kfree(th); + + if (rc) + ce = ERR_PTR(rc); + + return ce; +} + +/* Update an expired cache entry by getting a new DFS referral from server */ +static struct dfs_cache_entry * +update_cache_entry(const unsigned int xid, struct cifs_ses *ses, + const struct nls_table *nls_codepage, int remap, + const char *path, struct dfs_cache_entry *ce) +{ + int rc; + struct dfs_info3_param *refs = NULL; + int numrefs = 0; + + cifs_dbg(FYI, "%s: update expired cache entry\n", __func__); + /* + * Check if caller provided enough parameters to update an expired + * entry. + */ + if (!ses || !ses->server || !ses->server->ops->get_dfs_refer) + return ERR_PTR(-ETIME); + if (unlikely(!nls_codepage)) + return ERR_PTR(-ETIME); + + cifs_dbg(FYI, "%s: DFS referral request for %s\n", __func__, path); + + rc = ses->server->ops->get_dfs_refer(xid, ses, path, &refs, &numrefs, + nls_codepage, remap); + if (rc) + ce = ERR_PTR(rc); + else + ce = __update_cache_entry(path, refs, numrefs); + + dump_refs(refs, numrefs); + free_dfs_info_array(refs, numrefs); + + return ce; +} + +/* + * Find, create or update a DFS cache entry. + * + * If the entry wasn't found, it will create a new one. Or if it was found but + * expired, then it will update the entry accordingly. + * + * For interlinks, __cifs_dfs_mount() and expand_dfs_referral() are supposed to + * handle them properly. + */ +static struct dfs_cache_entry * +do_dfs_cache_find(const unsigned int xid, struct cifs_ses *ses, + const struct nls_table *nls_codepage, int remap, + const char *path, bool noreq) +{ + int rc; + unsigned int h; + struct dfs_cache_entry *ce; + struct dfs_info3_param *nrefs; + int numnrefs; + + cifs_dbg(FYI, "%s: search path: %s\n", __func__, path); + + ce = find_cache_entry(path, &h); + if (IS_ERR(ce)) { + cifs_dbg(FYI, "%s: cache miss\n", __func__); + /* + * If @noreq is set, no requests will be sent to the server for + * either updating or getting a new DFS referral. + */ + if (noreq) + return ce; + /* + * No cache entry was found, so check for valid parameters that + * will be required to get a new DFS referral and then create a + * new cache entry. + */ + if (!ses || !ses->server || !ses->server->ops->get_dfs_refer) { + ce = ERR_PTR(-EOPNOTSUPP); + return ce; + } + if (unlikely(!nls_codepage)) { + ce = ERR_PTR(-EINVAL); + return ce; + } + + nrefs = NULL; + numnrefs = 0; + + cifs_dbg(FYI, "%s: DFS referral request for %s\n", __func__, + path); + + rc = ses->server->ops->get_dfs_refer(xid, ses, path, &nrefs, + &numnrefs, nls_codepage, + remap); + if (rc) { + ce = ERR_PTR(rc); + return ce; + } + + dump_refs(nrefs, numnrefs); + + cifs_dbg(FYI, "%s: new cache entry\n", __func__); + + if (dfs_cache_count >= DFS_CACHE_MAX_ENTRIES) { + cifs_dbg(FYI, "%s: reached max cache size (%d)", + __func__, DFS_CACHE_MAX_ENTRIES); + remove_oldest_entry(); + } + ce = add_cache_entry(h, path, nrefs, numnrefs); + free_dfs_info_array(nrefs, numnrefs); + + if (IS_ERR(ce)) + return ce; + + dfs_cache_count++; + } + + dump_ce(ce); + + /* Just return the found cache entry in case @noreq is set */ + if (noreq) + return ce; + + if (cache_entry_expired(ce)) { + cifs_dbg(FYI, "%s: expired cache entry\n", __func__); + ce = update_cache_entry(xid, ses, nls_codepage, remap, path, + ce); + if (IS_ERR(ce)) { + cifs_dbg(FYI, "%s: failed to update expired entry\n", + __func__); + } + } + return ce; +} + +/* Set up a new DFS referral from a given cache entry */ +static int setup_ref(const char *path, const struct dfs_cache_entry *ce, + struct dfs_info3_param *ref, const char *tgt) +{ + int rc; + + cifs_dbg(FYI, "%s: set up new ref\n", __func__); + + memset(ref, 0, sizeof(*ref)); + + ref->path_name = kstrndup(path, strlen(path), GFP_KERNEL); + if (!ref->path_name) + return -ENOMEM; + + ref->path_consumed = ce->ce_path_consumed; + + ref->node_name = kstrndup(tgt, strlen(tgt), GFP_KERNEL); + if (!ref->node_name) { + rc = -ENOMEM; + goto err_free_path; + } + + ref->ttl = ce->ce_ttl; + ref->server_type = ce->ce_srvtype; + ref->ref_flag = ce->ce_flags; + + return 0; + +err_free_path: + kfree(ref->path_name); + ref->path_name = NULL; + return rc; +} + +/* Return target list of a DFS cache entry */ +static int get_tgt_list(const struct dfs_cache_entry *ce, + struct dfs_cache_tgt_list *tl) +{ + int rc; + struct list_head *head = &tl->tl_list; + struct dfs_cache_tgt *t; + struct dfs_cache_tgt_iterator *it, *nit; + + memset(tl, 0, sizeof(*tl)); + INIT_LIST_HEAD(head); + + list_for_each_entry(t, &ce->ce_tlist, t_list) { + it = kzalloc(sizeof(*it), GFP_KERNEL); + if (!it) { + rc = -ENOMEM; + goto err_free_it; + } + + it->it_name = kstrndup(t->t_name, strlen(t->t_name), + GFP_KERNEL); + if (!it->it_name) { + rc = -ENOMEM; + goto err_free_it; + } + + if (ce->ce_tgthint == t) + list_add(&it->it_list, head); + else + list_add_tail(&it->it_list, head); + } + tl->tl_numtgts = ce->ce_numtgts; + + return 0; + +err_free_it: + list_for_each_entry_safe(it, nit, head, it_list) { + kfree(it->it_name); + kfree(it); + } + return rc; +} + +/** + * dfs_cache_find - find a DFS cache entry + * + * If it doesn't find the cache entry, then it will get a DFS referral + * for @path and create a new entry. + * + * In case the cache entry exists but expired, it will get a DFS referral + * for @path and then update the respective cache entry. + * + * These parameters are passed down to the get_dfs_refer() call if it + * needs to be issued: + * @xid: syscall xid + * @ses: smb session to issue the request on + * @nls_codepage: charset conversion + * @remap: path character remapping type + * @path: path to lookup in DFS referral cache. + * + * @ref: when non-NULL, store single DFS referral result in it. + * @tgt_list: when non-NULL, store complete DFS target list in it. + * + * Return zero if the target was found, otherwise non-zero. + */ +int dfs_cache_find(const unsigned int xid, struct cifs_ses *ses, + const struct nls_table *nls_codepage, int remap, + const char *path, struct dfs_info3_param *ref, + struct dfs_cache_tgt_list *tgt_list) +{ + int rc; + char *npath; + struct dfs_cache_entry *ce; + + if (unlikely(!is_path_valid(path))) + return -EINVAL; + + rc = get_normalized_path(path, &npath); + if (rc) + return rc; + + mutex_lock(&dfs_cache_list_lock); + ce = do_dfs_cache_find(xid, ses, nls_codepage, remap, npath, false); + if (!IS_ERR(ce)) { + if (ref) + rc = setup_ref(path, ce, ref, get_tgt_name(ce)); + else + rc = 0; + if (!rc && tgt_list) + rc = get_tgt_list(ce, tgt_list); + } else { + rc = PTR_ERR(ce); + } + mutex_unlock(&dfs_cache_list_lock); + free_normalized_path(path, npath); + return rc; +} + +/** + * dfs_cache_noreq_find - find a DFS cache entry without sending any requests to + * the currently connected server. + * + * NOTE: This function will neither update a cache entry in case it was + * expired, nor create a new cache entry if @path hasn't been found. It heavily + * relies on an existing cache entry. + * + * @path: path to lookup in the DFS referral cache. + * @ref: when non-NULL, store single DFS referral result in it. + * @tgt_list: when non-NULL, store complete DFS target list in it. + * + * Return 0 if successful. + * Return -ENOENT if the entry was not found. + * Return non-zero for other errors. + */ +int dfs_cache_noreq_find(const char *path, struct dfs_info3_param *ref, + struct dfs_cache_tgt_list *tgt_list) +{ + int rc; + char *npath; + struct dfs_cache_entry *ce; + + if (unlikely(!is_path_valid(path))) + return -EINVAL; + + rc = get_normalized_path(path, &npath); + if (rc) + return rc; + + mutex_lock(&dfs_cache_list_lock); + ce = do_dfs_cache_find(0, NULL, NULL, 0, npath, true); + if (IS_ERR(ce)) { + rc = PTR_ERR(ce); + goto out; + } + + if (ref) + rc = setup_ref(path, ce, ref, get_tgt_name(ce)); + else + rc = 0; + if (!rc && tgt_list) + rc = get_tgt_list(ce, tgt_list); +out: + mutex_unlock(&dfs_cache_list_lock); + free_normalized_path(path, npath); + return rc; +} + +/** + * dfs_cache_update_tgthint - update target hint of a DFS cache entry + * + * If it doesn't find the cache entry, then it will get a DFS referral for @path + * and create a new entry. + * + * In case the cache entry exists but expired, it will get a DFS referral + * for @path and then update the respective cache entry. + * + * @xid: syscall id + * @ses: smb session + * @nls_codepage: charset conversion + * @remap: type of character remapping for paths + * @path: path to lookup in DFS referral cache. + * @it: DFS target iterator + * + * Return zero if the target hint was updated successfully, otherwise non-zero. + */ +int dfs_cache_update_tgthint(const unsigned int xid, struct cifs_ses *ses, + const struct nls_table *nls_codepage, int remap, + const char *path, + const struct dfs_cache_tgt_iterator *it) +{ + int rc; + char *npath; + struct dfs_cache_entry *ce; + struct dfs_cache_tgt *t; + + if (unlikely(!is_path_valid(path))) + return -EINVAL; + + rc = get_normalized_path(path, &npath); + if (rc) + return rc; + + cifs_dbg(FYI, "%s: path: %s\n", __func__, npath); + + mutex_lock(&dfs_cache_list_lock); + ce = do_dfs_cache_find(xid, ses, nls_codepage, remap, npath, false); + if (IS_ERR(ce)) { + rc = PTR_ERR(ce); + goto out; + } + + rc = 0; + + t = ce->ce_tgthint; + + if (likely(!strcasecmp(it->it_name, t->t_name))) + goto out; + + list_for_each_entry(t, &ce->ce_tlist, t_list) { + if (!strcasecmp(t->t_name, it->it_name)) { + ce->ce_tgthint = t; + cifs_dbg(FYI, "%s: new target hint: %s\n", __func__, + it->it_name); + break; + } + } + +out: + mutex_unlock(&dfs_cache_list_lock); + free_normalized_path(path, npath); + return rc; +} + +/** + * dfs_cache_noreq_update_tgthint - update target hint of a DFS cache entry + * without sending any requests to the currently connected server. + * + * NOTE: This function will neither update a cache entry in case it was + * expired, nor create a new cache entry if @path hasn't been found. It heavily + * relies on an existing cache entry. + * + * @path: path to lookup in DFS referral cache. + * @it: target iterator which contains the target hint to update the cache + * entry with. + * + * Return zero if the target hint was updated successfully, otherwise non-zero. + */ +int dfs_cache_noreq_update_tgthint(const char *path, + const struct dfs_cache_tgt_iterator *it) +{ + int rc; + char *npath; + struct dfs_cache_entry *ce; + struct dfs_cache_tgt *t; + + if (unlikely(!is_path_valid(path)) || !it) + return -EINVAL; + + rc = get_normalized_path(path, &npath); + if (rc) + return rc; + + cifs_dbg(FYI, "%s: path: %s\n", __func__, npath); + + mutex_lock(&dfs_cache_list_lock); + + ce = do_dfs_cache_find(0, NULL, NULL, 0, npath, true); + if (IS_ERR(ce)) { + rc = PTR_ERR(ce); + goto out; + } + + rc = 0; + + t = ce->ce_tgthint; + + if (unlikely(!strcasecmp(it->it_name, t->t_name))) + goto out; + + list_for_each_entry(t, &ce->ce_tlist, t_list) { + if (!strcasecmp(t->t_name, it->it_name)) { + ce->ce_tgthint = t; + cifs_dbg(FYI, "%s: new target hint: %s\n", __func__, + it->it_name); + break; + } + } + +out: + mutex_unlock(&dfs_cache_list_lock); + free_normalized_path(path, npath); + return rc; +} + +/** + * dfs_cache_get_tgt_referral - returns a DFS referral (@ref) from a given + * target iterator (@it). + * + * @path: path to lookup in DFS referral cache. + * @it: DFS target iterator. + * @ref: DFS referral pointer to set up the gathered information. + * + * Return zero if the DFS referral was set up correctly, otherwise non-zero. + */ +int dfs_cache_get_tgt_referral(const char *path, + const struct dfs_cache_tgt_iterator *it, + struct dfs_info3_param *ref) +{ + int rc; + char *npath; + struct dfs_cache_entry *ce; + unsigned int h; + + if (!it || !ref) + return -EINVAL; + if (unlikely(!is_path_valid(path))) + return -EINVAL; + + rc = get_normalized_path(path, &npath); + if (rc) + return rc; + + cifs_dbg(FYI, "%s: path: %s\n", __func__, npath); + + mutex_lock(&dfs_cache_list_lock); + + ce = find_cache_entry(npath, &h); + if (IS_ERR(ce)) { + rc = PTR_ERR(ce); + goto out; + } + + cifs_dbg(FYI, "%s: target name: %s\n", __func__, it->it_name); + + rc = setup_ref(path, ce, ref, it->it_name); + +out: + mutex_unlock(&dfs_cache_list_lock); + free_normalized_path(path, npath); + return rc; +} + +static int dup_vol(struct smb_vol *vol, struct smb_vol *new) +{ + memcpy(new, vol, sizeof(*new)); + + if (vol->username) { + new->username = kstrndup(vol->username, strlen(vol->username), + GFP_KERNEL); + if (!new->username) + return -ENOMEM; + } + if (vol->password) { + new->password = kstrndup(vol->password, strlen(vol->password), + GFP_KERNEL); + if (!new->password) + goto err_free_username; + } + if (vol->UNC) { + cifs_dbg(FYI, "%s: vol->UNC: %s\n", __func__, vol->UNC); + new->UNC = kstrndup(vol->UNC, strlen(vol->UNC), GFP_KERNEL); + if (!new->UNC) + goto err_free_password; + } + if (vol->domainname) { + new->domainname = kstrndup(vol->domainname, + strlen(vol->domainname), GFP_KERNEL); + if (!new->domainname) + goto err_free_unc; + } + if (vol->iocharset) { + new->iocharset = kstrndup(vol->iocharset, + strlen(vol->iocharset), GFP_KERNEL); + if (!new->iocharset) + goto err_free_domainname; + } + if (vol->prepath) { + cifs_dbg(FYI, "%s: vol->prepath: %s\n", __func__, vol->prepath); + new->prepath = kstrndup(vol->prepath, strlen(vol->prepath), + GFP_KERNEL); + if (!new->prepath) + goto err_free_iocharset; + } + + return 0; + +err_free_iocharset: + kfree(new->iocharset); +err_free_domainname: + kfree(new->domainname); +err_free_unc: + kfree(new->UNC); +err_free_password: + kzfree(new->password); +err_free_username: + kfree(new->username); + kfree(new); + return -ENOMEM; +} + +/** + * dfs_cache_add_vol - add a cifs volume during mount() that will be handled by + * DFS cache refresh worker. + * + * @vol: cifs volume. + * @fullpath: origin full path. + * + * Return zero if volume was set up correctly, otherwise non-zero. + */ +int dfs_cache_add_vol(struct smb_vol *vol, const char *fullpath) +{ + int rc; + struct dfs_cache_vol_info *vi; + + if (!vol || !fullpath) + return -EINVAL; + + cifs_dbg(FYI, "%s: fullpath: %s\n", __func__, fullpath); + + vi = kzalloc(sizeof(*vi), GFP_KERNEL); + if (!vi) + return -ENOMEM; + + vi->vi_fullpath = kstrndup(fullpath, strlen(fullpath), GFP_KERNEL); + if (!vi->vi_fullpath) { + rc = -ENOMEM; + goto err_free_vi; + } + + rc = dup_vol(vol, &vi->vi_vol); + if (rc) + goto err_free_fullpath; + + mutex_lock(&dfs_cache.dc_lock); + list_add_tail(&vi->vi_list, &dfs_cache.dc_vol_list); + mutex_unlock(&dfs_cache.dc_lock); + return 0; + +err_free_fullpath: + kfree(vi->vi_fullpath); +err_free_vi: + kfree(vi); + return rc; +} + +static inline struct dfs_cache_vol_info *find_vol(const char *fullpath) +{ + struct dfs_cache_vol_info *vi; + + list_for_each_entry(vi, &dfs_cache.dc_vol_list, vi_list) { + cifs_dbg(FYI, "%s: vi->vi_fullpath: %s\n", __func__, + vi->vi_fullpath); + if (!strcasecmp(vi->vi_fullpath, fullpath)) + return vi; + } + return ERR_PTR(-ENOENT); +} + +/** + * dfs_cache_update_vol - update vol info in DFS cache after failover + * + * @fullpath: fullpath to look up in volume list. + * @server: TCP ses pointer. + * + * Return zero if volume was updated, otherwise non-zero. + */ +int dfs_cache_update_vol(const char *fullpath, struct TCP_Server_Info *server) +{ + int rc; + struct dfs_cache_vol_info *vi; + + if (!fullpath || !server) + return -EINVAL; + + cifs_dbg(FYI, "%s: fullpath: %s\n", __func__, fullpath); + + mutex_lock(&dfs_cache.dc_lock); + + vi = find_vol(fullpath); + if (IS_ERR(vi)) { + rc = PTR_ERR(vi); + goto out; + } + + cifs_dbg(FYI, "%s: updating volume info\n", __func__); + memcpy(&vi->vi_vol.dstaddr, &server->dstaddr, + sizeof(vi->vi_vol.dstaddr)); + rc = 0; + +out: + mutex_unlock(&dfs_cache.dc_lock); + return rc; +} + +/** + * dfs_cache_del_vol - remove volume info in DFS cache during umount() + * + * @fullpath: fullpath to look up in volume list. + */ +void dfs_cache_del_vol(const char *fullpath) +{ + struct dfs_cache_vol_info *vi; + + if (!fullpath || !*fullpath) + return; + + cifs_dbg(FYI, "%s: fullpath: %s\n", __func__, fullpath); + + mutex_lock(&dfs_cache.dc_lock); + vi = find_vol(fullpath); + if (!IS_ERR(vi)) + free_vol(vi); + mutex_unlock(&dfs_cache.dc_lock); +} + +/* Get all tcons that are within a DFS namespace and can be refreshed */ +static void get_tcons(struct TCP_Server_Info *server, struct list_head *head) +{ + struct cifs_ses *ses; + struct cifs_tcon *tcon; + + INIT_LIST_HEAD(head); + + spin_lock(&cifs_tcp_ses_lock); + list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) { + list_for_each_entry(tcon, &ses->tcon_list, tcon_list) { + if (!tcon->need_reconnect && !tcon->need_reopen_files && + tcon->dfs_path) { + tcon->tc_count++; + list_add_tail(&tcon->ulist, head); + } + } + if (ses->tcon_ipc && !ses->tcon_ipc->need_reconnect && + ses->tcon_ipc->dfs_path) { + list_add_tail(&ses->tcon_ipc->ulist, head); + } + } + spin_unlock(&cifs_tcp_ses_lock); +} + +/* Refresh DFS cache entry from a given tcon */ +static void do_refresh_tcon(struct dfs_cache *dc, struct cifs_tcon *tcon) +{ + int rc = 0; + unsigned int xid; + char *path, *npath; + unsigned int h; + struct dfs_cache_entry *ce; + struct dfs_info3_param *refs = NULL; + int numrefs = 0; + + xid = get_xid(); + + path = tcon->dfs_path + 1; + + rc = get_normalized_path(path, &npath); + if (rc) + goto out; + + mutex_lock(&dfs_cache_list_lock); + ce = find_cache_entry(npath, &h); + mutex_unlock(&dfs_cache_list_lock); + + if (IS_ERR(ce)) { + rc = PTR_ERR(ce); + goto out; + } + + if (!cache_entry_expired(ce)) + goto out; + + if (unlikely(!tcon->ses->server->ops->get_dfs_refer)) { + rc = -EOPNOTSUPP; + } else { + rc = tcon->ses->server->ops->get_dfs_refer(xid, tcon->ses, path, + &refs, &numrefs, + dc->dc_nlsc, + tcon->remap); + if (!rc) { + mutex_lock(&dfs_cache_list_lock); + ce = __update_cache_entry(npath, refs, numrefs); + mutex_unlock(&dfs_cache_list_lock); + dump_refs(refs, numrefs); + free_dfs_info_array(refs, numrefs); + if (IS_ERR(ce)) + rc = PTR_ERR(ce); + } + } + if (rc) + cifs_dbg(FYI, "%s: failed to update expired entry\n", __func__); +out: + free_xid(xid); + free_normalized_path(path, npath); +} + +/* + * Worker that will refresh DFS cache based on lowest TTL value from a DFS + * referral. + * + * FIXME: ensure that all requests are sent to DFS root for refreshing the + * cache. + */ +static void refresh_cache_worker(struct work_struct *work) +{ + struct dfs_cache *dc = container_of(work, struct dfs_cache, + dc_refresh.work); + struct dfs_cache_vol_info *vi; + struct TCP_Server_Info *server; + LIST_HEAD(list); + struct cifs_tcon *tcon, *ntcon; + + mutex_lock(&dc->dc_lock); + + list_for_each_entry(vi, &dc->dc_vol_list, vi_list) { + server = cifs_find_tcp_session(&vi->vi_vol); + if (IS_ERR_OR_NULL(server)) + continue; + if (server->tcpStatus != CifsGood) + goto next; + get_tcons(server, &list); + list_for_each_entry_safe(tcon, ntcon, &list, ulist) { + do_refresh_tcon(dc, tcon); + list_del_init(&tcon->ulist); + cifs_put_tcon(tcon); + } +next: + cifs_put_tcp_session(server, 0); + } + queue_delayed_work(cifsiod_wq, &dc->dc_refresh, dc->dc_ttl * HZ); + mutex_unlock(&dc->dc_lock); +} |