int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
{
- /* If tcp session is not an dfs connection, then reconnect to last target server */
- spin_lock(&server->srv_lock);
- if (!server->is_dfs_conn) {
- spin_unlock(&server->srv_lock);
- return __cifs_reconnect(server, mark_smb_session);
- }
- spin_unlock(&server->srv_lock);
-
mutex_lock(&server->refpath_lock);
- if (!server->origin_fullpath || !server->leaf_fullpath) {
+ if (!server->leaf_fullpath) {
mutex_unlock(&server->refpath_lock);
return __cifs_reconnect(server, mark_smb_session);
}
return port == *sport;
}
-static bool
-match_address(struct TCP_Server_Info *server, struct sockaddr *addr,
- struct sockaddr *srcaddr)
+static bool match_server_address(struct TCP_Server_Info *server, struct sockaddr *addr)
{
switch (addr->sa_family) {
case AF_INET: {
return false; /* don't expect to be here */
}
- if (!cifs_match_ipaddr(srcaddr, (struct sockaddr *)&server->srcaddr))
- return false;
-
return true;
}
}
/* this function must be called with srv_lock held */
-static int match_server(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
+static int match_server(struct TCP_Server_Info *server, struct smb3_fs_context *ctx,
+ bool dfs_super_cmp)
{
struct sockaddr *addr = (struct sockaddr *)&ctx->dstaddr;
if (!net_eq(cifs_net_ns(server), current->nsproxy->net_ns))
return 0;
- if (strcasecmp(server->hostname, ctx->server_hostname))
- return 0;
-
- if (!match_address(server, addr,
- (struct sockaddr *)&ctx->srcaddr))
- return 0;
-
- if (!match_port(server, addr))
+ if (!cifs_match_ipaddr((struct sockaddr *)&ctx->srcaddr,
+ (struct sockaddr *)&server->srcaddr))
return 0;
+ /*
+ * When matching DFS superblocks, we only check for original source pathname as the
+ * currently connected target might be different than the one parsed earlier in i.e.
+ * mount.cifs(8).
+ */
+ if (dfs_super_cmp) {
+ if (!ctx->source || !server->origin_fullpath ||
+ strcasecmp(server->origin_fullpath, ctx->source))
+ return 0;
+ } else {
+ /* Skip addr, hostname and port matching for DFS connections */
+ if (server->leaf_fullpath) {
+ if (!ctx->leaf_fullpath ||
+ strcasecmp(server->leaf_fullpath, ctx->leaf_fullpath))
+ return 0;
+ } else if (strcasecmp(server->hostname, ctx->server_hostname) ||
+ !match_server_address(server, addr) ||
+ !match_port(server, addr)) {
+ return 0;
+ }
+ }
if (!match_security(server, ctx))
return 0;
spin_lock(&cifs_tcp_ses_lock);
list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) {
spin_lock(&server->srv_lock);
-#ifdef CONFIG_CIFS_DFS_UPCALL
- /*
- * DFS failover implementation in cifs_reconnect() requires unique tcp sessions for
- * DFS connections to do failover properly, so avoid sharing them with regular
- * shares or even links that may connect to same server but having completely
- * different failover targets.
- */
- if (server->is_dfs_conn) {
- spin_unlock(&server->srv_lock);
- continue;
- }
-#endif
/*
* Skip ses channels since they're only handled in lower layers
* (e.g. cifs_send_recv).
*/
- if (CIFS_SERVER_IS_CHAN(server) || !match_server(server, ctx)) {
+ if (CIFS_SERVER_IS_CHAN(server) || !match_server(server, ctx, false)) {
spin_unlock(&server->srv_lock);
continue;
}
goto out_err;
}
+ if (ctx->leaf_fullpath) {
+ tcp_ses->leaf_fullpath = kstrdup(ctx->leaf_fullpath, GFP_KERNEL);
+ if (!tcp_ses->leaf_fullpath) {
+ rc = -ENOMEM;
+ goto out_err;
+ }
+ tcp_ses->current_fullpath = tcp_ses->leaf_fullpath;
+ }
+
if (ctx->nosharesock)
tcp_ses->nosharesock = true;
if (CIFS_SERVER_IS_CHAN(tcp_ses))
cifs_put_tcp_session(tcp_ses->primary_server, false);
kfree(tcp_ses->hostname);
+ kfree(tcp_ses->leaf_fullpath);
if (tcp_ses->ssocket)
sock_release(tcp_ses->ssocket);
kfree(tcp_ses);
}
/* this function must be called with tc_lock held */
-static int match_tcon(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
+static int match_tcon(struct cifs_tcon *tcon, struct smb3_fs_context *ctx, bool dfs_super_cmp)
{
if (tcon->status == TID_EXITING)
return 0;
- if (strncmp(tcon->tree_name, ctx->UNC, MAX_TREE_SIZE))
+ /* Skip UNC validation when matching DFS superblocks */
+ if (!dfs_super_cmp && strncmp(tcon->tree_name, ctx->UNC, MAX_TREE_SIZE))
return 0;
if (tcon->seal != ctx->seal)
return 0;
spin_lock(&cifs_tcp_ses_lock);
list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
spin_lock(&tcon->tc_lock);
- if (!match_tcon(tcon, ctx)) {
+ if (!match_tcon(tcon, ctx, false)) {
spin_unlock(&tcon->tc_lock);
continue;
}
struct cifs_ses *ses;
struct cifs_tcon *tcon;
struct tcon_link *tlink;
+ bool dfs_super_cmp;
int rc = 0;
spin_lock(&cifs_tcp_ses_lock);
ses = tcon->ses;
tcp_srv = ses->server;
+ dfs_super_cmp = IS_ENABLED(CONFIG_CIFS_DFS_UPCALL) && tcp_srv->origin_fullpath;
+
ctx = mnt_data->ctx;
spin_lock(&tcp_srv->srv_lock);
spin_lock(&ses->ses_lock);
spin_lock(&tcon->tc_lock);
- if (!match_server(tcp_srv, ctx) ||
+ if (!match_server(tcp_srv, ctx, dfs_super_cmp) ||
!match_session(ses, ctx) ||
- !match_tcon(tcon, ctx) ||
+ !match_tcon(tcon, ctx, dfs_super_cmp) ||
!match_prepath(sb, mnt_data)) {
rc = 0;
goto out;
}
/* Release all succeed connections */
-static inline void mount_put_conns(struct cifs_mount_ctx *mnt_ctx)
+void cifs_mount_put_conns(struct cifs_mount_ctx *mnt_ctx)
{
int rc = 0;
return rc;
}
-/* Get connections for tcp, ses and tcon */
-static int mount_get_conns(struct cifs_mount_ctx *mnt_ctx)
-{
- int rc;
-
- rc = cifs_mount_get_session(mnt_ctx);
- if (rc)
- return rc;
-
- return cifs_mount_get_tcon(mnt_ctx);
-}
-
static int mount_setup_tlink(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
struct cifs_tcon *tcon)
{
return 0;
}
-#ifdef CONFIG_CIFS_DFS_UPCALL
-/* Get unique dfs connections */
-static int mount_get_dfs_conns(struct cifs_mount_ctx *mnt_ctx)
-{
- int rc;
-
- mnt_ctx->fs_ctx->nosharesock = true;
- rc = mount_get_conns(mnt_ctx);
- if (mnt_ctx->server) {
- cifs_dbg(FYI, "%s: marking tcp session as a dfs connection\n", __func__);
- spin_lock(&mnt_ctx->server->srv_lock);
- mnt_ctx->server->is_dfs_conn = true;
- spin_unlock(&mnt_ctx->server->srv_lock);
- }
- return rc;
-}
-
-/*
- * cifs_build_path_to_root returns full path to root when we do not have an
- * existing connection (tcon)
- */
-static char *
-build_unc_path_to_root(const struct smb3_fs_context *ctx,
- const struct cifs_sb_info *cifs_sb, bool useppath)
-{
- char *full_path, *pos;
- unsigned int pplen = useppath && ctx->prepath ?
- strlen(ctx->prepath) + 1 : 0;
- unsigned int unc_len = strnlen(ctx->UNC, MAX_TREE_SIZE + 1);
-
- if (unc_len > MAX_TREE_SIZE)
- return ERR_PTR(-EINVAL);
-
- full_path = kmalloc(unc_len + pplen + 1, GFP_KERNEL);
- if (full_path == NULL)
- return ERR_PTR(-ENOMEM);
-
- memcpy(full_path, ctx->UNC, unc_len);
- pos = full_path + unc_len;
-
- if (pplen) {
- *pos = CIFS_DIR_SEP(cifs_sb);
- memcpy(pos + 1, ctx->prepath, pplen);
- pos += pplen;
- }
-
- *pos = '\0'; /* add trailing null */
- convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb));
- cifs_dbg(FYI, "%s: full_path=%s\n", __func__, full_path);
- return full_path;
-}
-#endif
-
static int
cifs_are_all_path_components_accessible(struct TCP_Server_Info *server,
unsigned int xid,
*
* Return -EREMOTE if it is, otherwise 0 or -errno.
*/
-static int is_path_remote(struct cifs_mount_ctx *mnt_ctx)
+int cifs_is_path_remote(struct cifs_mount_ctx *mnt_ctx)
{
int rc;
struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
}
#ifdef CONFIG_CIFS_DFS_UPCALL
-static void set_root_ses(struct cifs_mount_ctx *mnt_ctx)
-{
- if (mnt_ctx->ses) {
- spin_lock(&cifs_tcp_ses_lock);
- mnt_ctx->ses->ses_count++;
- spin_unlock(&cifs_tcp_ses_lock);
- dfs_cache_add_refsrv_session(&mnt_ctx->mount_id, mnt_ctx->ses);
- }
- mnt_ctx->root_ses = mnt_ctx->ses;
-}
-
-static int is_dfs_mount(struct cifs_mount_ctx *mnt_ctx, bool *isdfs,
- struct dfs_cache_tgt_list *root_tl)
-{
- int rc;
- struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
- struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
-
- *isdfs = true;
-
- rc = mount_get_conns(mnt_ctx);
- /*
- * If called with 'nodfs' mount option, then skip DFS resolving. Otherwise unconditionally
- * try to get an DFS referral (even cached) to determine whether it is an DFS mount.
- *
- * Skip prefix path to provide support for DFS referrals from w2k8 servers which don't seem
- * to respond with PATH_NOT_COVERED to requests that include the prefix.
- */
- if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) ||
- dfs_cache_find(mnt_ctx->xid, mnt_ctx->ses, cifs_sb->local_nls, cifs_remap(cifs_sb),
- ctx->UNC + 1, NULL, root_tl)) {
- if (rc)
- return rc;
- /* Check if it is fully accessible and then mount it */
- rc = is_path_remote(mnt_ctx);
- if (!rc)
- *isdfs = false;
- else if (rc != -EREMOTE)
- return rc;
- }
- return 0;
-}
-
-static int connect_dfs_target(struct cifs_mount_ctx *mnt_ctx, const char *full_path,
- const char *ref_path, struct dfs_cache_tgt_iterator *tit)
-{
- int rc;
- struct dfs_info3_param ref = {};
- struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
-
- cifs_dbg(FYI, "%s: full_path=%s ref_path=%s target=%s\n", __func__, full_path, ref_path,
- dfs_cache_get_tgt_name(tit));
-
- rc = dfs_cache_get_tgt_referral(ref_path, tit, &ref);
- if (rc)
- goto out;
-
- rc = dfs_parse_target_referral(full_path + 1, &ref, mnt_ctx->fs_ctx);
- if (rc)
- goto out;
-
- /* XXX: maybe check if we were actually redirected and avoid reconnecting? */
- mount_put_conns(mnt_ctx);
- rc = mount_get_dfs_conns(mnt_ctx);
-
- if (!rc) {
- if (cifs_is_referral_server(mnt_ctx->tcon, &ref))
- set_root_ses(mnt_ctx);
- rc = dfs_cache_update_tgthint(mnt_ctx->xid, mnt_ctx->root_ses, cifs_sb->local_nls,
- cifs_remap(cifs_sb), ref_path, tit);
- }
-
-out:
- free_dfs_info_param(&ref);
- return rc;
-}
-
-static int connect_dfs_root(struct cifs_mount_ctx *mnt_ctx, struct dfs_cache_tgt_list *root_tl)
-{
- int rc;
- char *full_path;
- struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
- struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
- struct dfs_cache_tgt_iterator *tit;
-
- /* Put initial connections as they might be shared with other mounts. We need unique dfs
- * connections per mount to properly failover, so mount_get_dfs_conns() must be used from
- * now on.
- */
- mount_put_conns(mnt_ctx);
- mount_get_dfs_conns(mnt_ctx);
- set_root_ses(mnt_ctx);
-
- full_path = build_unc_path_to_root(ctx, cifs_sb, true);
- if (IS_ERR(full_path))
- return PTR_ERR(full_path);
-
- mnt_ctx->origin_fullpath = dfs_cache_canonical_path(ctx->UNC, cifs_sb->local_nls,
- cifs_remap(cifs_sb));
- if (IS_ERR(mnt_ctx->origin_fullpath)) {
- rc = PTR_ERR(mnt_ctx->origin_fullpath);
- mnt_ctx->origin_fullpath = NULL;
- goto out;
- }
-
- /* Try all dfs root targets */
- for (rc = -ENOENT, tit = dfs_cache_get_tgt_iterator(root_tl);
- tit; tit = dfs_cache_get_next_tgt(root_tl, tit)) {
- rc = connect_dfs_target(mnt_ctx, full_path, mnt_ctx->origin_fullpath + 1, tit);
- if (!rc) {
- mnt_ctx->leaf_fullpath = kstrdup(mnt_ctx->origin_fullpath, GFP_KERNEL);
- if (!mnt_ctx->leaf_fullpath)
- rc = -ENOMEM;
- break;
- }
- }
-
-out:
- kfree(full_path);
- return rc;
-}
-
-static int __follow_dfs_link(struct cifs_mount_ctx *mnt_ctx)
-{
- int rc;
- struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
- struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
- char *full_path;
- struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
- struct dfs_cache_tgt_iterator *tit;
-
- full_path = build_unc_path_to_root(ctx, cifs_sb, true);
- if (IS_ERR(full_path))
- return PTR_ERR(full_path);
-
- kfree(mnt_ctx->leaf_fullpath);
- mnt_ctx->leaf_fullpath = dfs_cache_canonical_path(full_path, cifs_sb->local_nls,
- cifs_remap(cifs_sb));
- if (IS_ERR(mnt_ctx->leaf_fullpath)) {
- rc = PTR_ERR(mnt_ctx->leaf_fullpath);
- mnt_ctx->leaf_fullpath = NULL;
- goto out;
- }
-
- /* Get referral from dfs link */
- rc = dfs_cache_find(mnt_ctx->xid, mnt_ctx->root_ses, cifs_sb->local_nls,
- cifs_remap(cifs_sb), mnt_ctx->leaf_fullpath + 1, NULL, &tl);
- if (rc)
- goto out;
-
- /* Try all dfs link targets. If an I/O fails from currently connected DFS target with an
- * error other than STATUS_PATH_NOT_COVERED (-EREMOTE), then retry it from other targets as
- * specified in MS-DFSC "3.1.5.2 I/O Operation to Target Fails with an Error Other Than
- * STATUS_PATH_NOT_COVERED."
- */
- for (rc = -ENOENT, tit = dfs_cache_get_tgt_iterator(&tl);
- tit; tit = dfs_cache_get_next_tgt(&tl, tit)) {
- rc = connect_dfs_target(mnt_ctx, full_path, mnt_ctx->leaf_fullpath + 1, tit);
- if (!rc) {
- rc = is_path_remote(mnt_ctx);
- if (!rc || rc == -EREMOTE)
- break;
- }
- }
-
-out:
- kfree(full_path);
- dfs_cache_free_tgts(&tl);
- return rc;
-}
-
-static int follow_dfs_link(struct cifs_mount_ctx *mnt_ctx)
-{
- int rc;
- struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
- struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
- char *full_path;
- int num_links = 0;
-
- full_path = build_unc_path_to_root(ctx, cifs_sb, true);
- if (IS_ERR(full_path))
- return PTR_ERR(full_path);
-
- kfree(mnt_ctx->origin_fullpath);
- mnt_ctx->origin_fullpath = dfs_cache_canonical_path(full_path, cifs_sb->local_nls,
- cifs_remap(cifs_sb));
- kfree(full_path);
-
- if (IS_ERR(mnt_ctx->origin_fullpath)) {
- rc = PTR_ERR(mnt_ctx->origin_fullpath);
- mnt_ctx->origin_fullpath = NULL;
- return rc;
- }
-
- do {
- rc = __follow_dfs_link(mnt_ctx);
- if (!rc || rc != -EREMOTE)
- break;
- } while (rc = -ELOOP, ++num_links < MAX_NESTED_LINKS);
-
- return rc;
-}
-
-/* Set up DFS referral paths for failover */
-static void setup_server_referral_paths(struct cifs_mount_ctx *mnt_ctx)
-{
- struct TCP_Server_Info *server = mnt_ctx->server;
-
- mutex_lock(&server->refpath_lock);
- server->origin_fullpath = mnt_ctx->origin_fullpath;
- server->leaf_fullpath = mnt_ctx->leaf_fullpath;
- server->current_fullpath = mnt_ctx->leaf_fullpath;
- mutex_unlock(&server->refpath_lock);
- mnt_ctx->origin_fullpath = mnt_ctx->leaf_fullpath = NULL;
-}
-
int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
{
- int rc;
struct cifs_mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
- struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
bool isdfs;
+ int rc;
- rc = is_dfs_mount(&mnt_ctx, &isdfs, &tl);
+ uuid_gen(&mnt_ctx.mount_id);
+ rc = dfs_mount_share(&mnt_ctx, &isdfs);
if (rc)
goto error;
if (!isdfs)
goto out;
- /* proceed as DFS mount */
- uuid_gen(&mnt_ctx.mount_id);
- rc = connect_dfs_root(&mnt_ctx, &tl);
- dfs_cache_free_tgts(&tl);
-
- if (rc)
- goto error;
-
- rc = is_path_remote(&mnt_ctx);
- if (rc)
- rc = follow_dfs_link(&mnt_ctx);
- if (rc)
- goto error;
-
- setup_server_referral_paths(&mnt_ctx);
/*
* After reconnecting to a different server, unique ids won't match anymore, so we disable
* serverino. This prevents dentry revalidation to think the dentry are stale (ESTALE).
dfs_cache_put_refsrv_sessions(&mnt_ctx.mount_id);
kfree(mnt_ctx.origin_fullpath);
kfree(mnt_ctx.leaf_fullpath);
- mount_put_conns(&mnt_ctx);
+ cifs_mount_put_conns(&mnt_ctx);
return rc;
}
#else
int rc = 0;
struct cifs_mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
- rc = mount_get_conns(&mnt_ctx);
+ rc = cifs_mount_get_session(&mnt_ctx);
if (rc)
goto error;
- if (mnt_ctx.tcon) {
- rc = is_path_remote(&mnt_ctx);
- if (rc == -EREMOTE)
- rc = -EOPNOTSUPP;
- if (rc)
- goto error;
- }
+ rc = cifs_mount_get_tcon(&mnt_ctx);
+ if (rc)
+ goto error;
+
+ rc = cifs_is_path_remote(&mnt_ctx);
+ if (rc == -EREMOTE)
+ rc = -EOPNOTSUPP;
+ if (rc)
+ goto error;
rc = mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
if (rc)
return rc;
error:
- mount_put_conns(&mnt_ctx);
+ cifs_mount_put_conns(&mnt_ctx);
return rc;
}
#endif
* Copyright (c) 2022 Paulo Alcantara <palcantara@suse.de>
*/
+#include <linux/namei.h>
#include "cifsproto.h"
#include "cifs_debug.h"
#include "dns_resolve.h"
kfree(path);
return rc;
}
+
+/*
+ * cifs_build_path_to_root returns full path to root when we do not have an
+ * existing connection (tcon)
+ */
+static char *build_unc_path_to_root(const struct smb3_fs_context *ctx,
+ const struct cifs_sb_info *cifs_sb, bool useppath)
+{
+ char *full_path, *pos;
+ unsigned int pplen = useppath && ctx->prepath ? strlen(ctx->prepath) + 1 : 0;
+ unsigned int unc_len = strnlen(ctx->UNC, MAX_TREE_SIZE + 1);
+
+ if (unc_len > MAX_TREE_SIZE)
+ return ERR_PTR(-EINVAL);
+
+ full_path = kmalloc(unc_len + pplen + 1, GFP_KERNEL);
+ if (full_path == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ memcpy(full_path, ctx->UNC, unc_len);
+ pos = full_path + unc_len;
+
+ if (pplen) {
+ *pos = CIFS_DIR_SEP(cifs_sb);
+ memcpy(pos + 1, ctx->prepath, pplen);
+ pos += pplen;
+ }
+
+ *pos = '\0'; /* add trailing null */
+ convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb));
+ cifs_dbg(FYI, "%s: full_path=%s\n", __func__, full_path);
+ return full_path;
+}
+
+static int get_session(struct cifs_mount_ctx *mnt_ctx, const char *full_path)
+{
+ struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
+ int rc;
+
+ ctx->leaf_fullpath = (char *)full_path;
+ rc = cifs_mount_get_session(mnt_ctx);
+ ctx->leaf_fullpath = NULL;
+
+ return rc;
+}
+
+static void set_root_ses(struct cifs_mount_ctx *mnt_ctx)
+{
+ if (mnt_ctx->ses) {
+ spin_lock(&cifs_tcp_ses_lock);
+ mnt_ctx->ses->ses_count++;
+ spin_unlock(&cifs_tcp_ses_lock);
+ dfs_cache_add_refsrv_session(&mnt_ctx->mount_id, mnt_ctx->ses);
+ }
+ mnt_ctx->root_ses = mnt_ctx->ses;
+}
+
+static int get_dfs_conn(struct cifs_mount_ctx *mnt_ctx, const char *ref_path, const char *full_path,
+ const struct dfs_cache_tgt_iterator *tit)
+{
+ struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
+ struct dfs_info3_param ref = {};
+ int rc;
+
+ rc = dfs_cache_get_tgt_referral(ref_path + 1, tit, &ref);
+ if (rc)
+ return rc;
+
+ rc = dfs_parse_target_referral(full_path + 1, &ref, ctx);
+ if (rc)
+ goto out;
+
+ cifs_mount_put_conns(mnt_ctx);
+ rc = get_session(mnt_ctx, ref_path);
+ if (rc)
+ goto out;
+
+ if (ref.flags & DFSREF_REFERRAL_SERVER)
+ set_root_ses(mnt_ctx);
+
+ rc = -EREMOTE;
+ if (ref.flags & DFSREF_STORAGE_SERVER) {
+ rc = cifs_mount_get_tcon(mnt_ctx);
+ if (rc)
+ goto out;
+
+ /* some servers may not advertise referral capability under ref.flags */
+ if (!(ref.flags & DFSREF_REFERRAL_SERVER) &&
+ is_tcon_dfs(mnt_ctx->tcon))
+ set_root_ses(mnt_ctx);
+
+ rc = cifs_is_path_remote(mnt_ctx);
+ }
+
+out:
+ free_dfs_info_param(&ref);
+ return rc;
+}
+
+static int __dfs_mount_share(struct cifs_mount_ctx *mnt_ctx)
+{
+ struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
+ struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
+ char *ref_path = NULL, *full_path = NULL;
+ struct dfs_cache_tgt_iterator *tit;
+ struct TCP_Server_Info *server;
+ char *origin_fullpath = NULL;
+ int num_links = 0;
+ int rc;
+
+ ref_path = dfs_get_path(cifs_sb, ctx->UNC);
+ if (IS_ERR(ref_path))
+ return PTR_ERR(ref_path);
+
+ full_path = build_unc_path_to_root(ctx, cifs_sb, true);
+ if (IS_ERR(full_path)) {
+ rc = PTR_ERR(full_path);
+ full_path = NULL;
+ goto out;
+ }
+
+ origin_fullpath = kstrdup(full_path, GFP_KERNEL);
+ if (!origin_fullpath) {
+ rc = -ENOMEM;
+ goto out;
+ }
+
+ do {
+ struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
+
+ rc = dfs_get_referral(mnt_ctx, ref_path + 1, NULL, &tl);
+ if (rc)
+ break;
+
+ tit = dfs_cache_get_tgt_iterator(&tl);
+ if (!tit) {
+ cifs_dbg(VFS, "%s: dfs referral (%s) with no targets\n", __func__,
+ ref_path + 1);
+ rc = -ENOENT;
+ dfs_cache_free_tgts(&tl);
+ break;
+ }
+
+ do {
+ rc = get_dfs_conn(mnt_ctx, ref_path, full_path, tit);
+ if (!rc)
+ break;
+ if (rc == -EREMOTE) {
+ if (++num_links > MAX_NESTED_LINKS) {
+ rc = -ELOOP;
+ break;
+ }
+ kfree(ref_path);
+ kfree(full_path);
+ ref_path = full_path = NULL;
+
+ full_path = build_unc_path_to_root(ctx, cifs_sb, true);
+ if (IS_ERR(full_path)) {
+ rc = PTR_ERR(full_path);
+ full_path = NULL;
+ } else {
+ ref_path = dfs_get_path(cifs_sb, full_path);
+ if (IS_ERR(ref_path)) {
+ rc = PTR_ERR(ref_path);
+ ref_path = NULL;
+ }
+ }
+ break;
+ }
+ } while ((tit = dfs_cache_get_next_tgt(&tl, tit)));
+ dfs_cache_free_tgts(&tl);
+ } while (rc == -EREMOTE);
+
+ if (!rc) {
+ server = mnt_ctx->server;
+
+ mutex_lock(&server->refpath_lock);
+ server->origin_fullpath = origin_fullpath;
+ server->current_fullpath = server->leaf_fullpath;
+ mutex_unlock(&server->refpath_lock);
+ origin_fullpath = NULL;
+ }
+
+out:
+ kfree(origin_fullpath);
+ kfree(ref_path);
+ kfree(full_path);
+ return rc;
+}
+
+int dfs_mount_share(struct cifs_mount_ctx *mnt_ctx, bool *isdfs)
+{
+ struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
+ struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
+ int rc;
+
+ *isdfs = false;
+
+ rc = get_session(mnt_ctx, NULL);
+ if (rc)
+ return rc;
+ mnt_ctx->root_ses = mnt_ctx->ses;
+ /*
+ * If called with 'nodfs' mount option, then skip DFS resolving. Otherwise unconditionally
+ * try to get an DFS referral (even cached) to determine whether it is an DFS mount.
+ *
+ * Skip prefix path to provide support for DFS referrals from w2k8 servers which don't seem
+ * to respond with PATH_NOT_COVERED to requests that include the prefix.
+ */
+ if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) ||
+ dfs_get_referral(mnt_ctx, ctx->UNC + 1, NULL, NULL)) {
+ rc = cifs_mount_get_tcon(mnt_ctx);
+ if (rc)
+ return rc;
+
+ rc = cifs_is_path_remote(mnt_ctx);
+ if (!rc || rc != -EREMOTE)
+ return rc;
+ }
+
+ *isdfs = true;
+ set_root_ses(mnt_ctx);
+
+ return __dfs_mount_share(mnt_ctx);
+}
projects / platform / kernel / linux-rpi.git / commitdiff