From: Paulo Alcantara pc@cjr.nz
[ Upstream commit c88f7dcd6d6429197fc2fd87b54a894ffcd48e8e ]
Mounting a dfs link that has nested links was already supported at mount(2), so make it work over reconnect as well.
Make the following case work:
* mount //root/dfs/link /mnt -o ... - final share: /server/share
* in server settings - change target folder of /root/dfs/link3 to /server/share2 - change target folder of /root/dfs/link2 to /root/dfs/link3 - change target folder of /root/dfs/link to /root/dfs/link2
* mount -o remount,... /mnt - refresh all dfs referrals - mark current connection for failover - cifs_reconnect() reconnects to root server - tree_connect() * checks that /root/dfs/link2 is a link, then chase it * checks that root/dfs/link3 is a link, then chase it * finally tree connect to /server/share2
If the mounted share is no longer accessible and a reconnect had been triggered, the client will retry it from both last referral path (/root/dfs/link3) and original referral path (/root/dfs/link).
Any new referral paths found while chasing dfs links over reconnect, it will be updated to TCP_Server_Info::leaf_fullpath, accordingly.
Signed-off-by: Paulo Alcantara (SUSE) pc@cjr.nz Signed-off-by: Steve French stfrench@microsoft.com Stable-dep-of: 1dcdf5f5b213 ("cifs: Fix connections leak when tlink setup failed") Signed-off-by: Sasha Levin sashal@kernel.org --- fs/cifs/cifs_dfs_ref.c | 59 +-- fs/cifs/cifs_fs_sb.h | 5 - fs/cifs/cifsglob.h | 24 +- fs/cifs/cifsproto.h | 5 +- fs/cifs/connect.c | 1138 ++++++++++++++++++++-------------------- fs/cifs/dfs_cache.c | 44 +- fs/cifs/misc.c | 62 +-- fs/cifs/smb2ops.c | 10 +- fs/cifs/smb2pdu.c | 6 +- 9 files changed, 660 insertions(+), 693 deletions(-)
diff --git a/fs/cifs/cifs_dfs_ref.c b/fs/cifs/cifs_dfs_ref.c index 007427ba75e5..b0864da9ef43 100644 --- a/fs/cifs/cifs_dfs_ref.c +++ b/fs/cifs/cifs_dfs_ref.c @@ -307,12 +307,8 @@ static struct vfsmount *cifs_dfs_do_mount(struct dentry *mntpt, static struct vfsmount *cifs_dfs_do_automount(struct dentry *mntpt) { struct cifs_sb_info *cifs_sb; - struct cifs_ses *ses; - struct cifs_tcon *tcon; void *page; - char *full_path, *root_path; - unsigned int xid; - int rc; + char *full_path; struct vfsmount *mnt;
cifs_dbg(FYI, "in %s\n", __func__); @@ -324,8 +320,6 @@ static struct vfsmount *cifs_dfs_do_automount(struct dentry *mntpt) * the double backslashes usually used in the UNC. This function * gives us the latter, so we must adjust the result. */ - mnt = ERR_PTR(-ENOMEM); - cifs_sb = CIFS_SB(mntpt->d_sb); if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) { mnt = ERR_PTR(-EREMOTE); @@ -341,60 +335,11 @@ static struct vfsmount *cifs_dfs_do_automount(struct dentry *mntpt) }
convert_delimiter(full_path, '\'); - cifs_dbg(FYI, "%s: full_path: %s\n", __func__, full_path);
- if (!cifs_sb_master_tlink(cifs_sb)) { - cifs_dbg(FYI, "%s: master tlink is NULL\n", __func__); - goto free_full_path; - } - - tcon = cifs_sb_master_tcon(cifs_sb); - if (!tcon) { - cifs_dbg(FYI, "%s: master tcon is NULL\n", __func__); - goto free_full_path; - } - - root_path = kstrdup(tcon->treeName, GFP_KERNEL); - if (!root_path) { - mnt = ERR_PTR(-ENOMEM); - goto free_full_path; - } - cifs_dbg(FYI, "%s: root path: %s\n", __func__, root_path); - - ses = tcon->ses; - xid = get_xid(); - - /* - * If DFS root has been expired, then unconditionally fetch it again to - * refresh DFS referral cache. - */ - rc = dfs_cache_find(xid, ses, cifs_sb->local_nls, cifs_remap(cifs_sb), - root_path + 1, NULL, NULL); - if (!rc) { - rc = dfs_cache_find(xid, ses, cifs_sb->local_nls, - cifs_remap(cifs_sb), full_path + 1, - NULL, NULL); - } - - free_xid(xid); - - if (rc) { - mnt = ERR_PTR(rc); - goto free_root_path; - } - /* - * OK - we were able to get and cache a referral for @full_path. - * - * Now, pass it down to cifs_mount() and it will retry every available - * node server in case of failures - no need to do it here. - */ mnt = cifs_dfs_do_mount(mntpt, cifs_sb, full_path); - cifs_dbg(FYI, "%s: cifs_dfs_do_mount:%s , mnt:%p\n", __func__, - full_path + 1, mnt); + cifs_dbg(FYI, "%s: cifs_dfs_do_mount:%s , mnt:%p\n", __func__, full_path + 1, mnt);
-free_root_path: - kfree(root_path); free_full_path: free_dentry_path(page); cdda_exit: diff --git a/fs/cifs/cifs_fs_sb.h b/fs/cifs/cifs_fs_sb.h index f97407520ea1..013a4bd65280 100644 --- a/fs/cifs/cifs_fs_sb.h +++ b/fs/cifs/cifs_fs_sb.h @@ -61,11 +61,6 @@ struct cifs_sb_info { /* only used when CIFS_MOUNT_USE_PREFIX_PATH is set */ char *prepath;
- /* - * Canonical DFS path initially provided by the mount call. We might connect to something - * different via DFS but we want to keep it to do failover properly. - */ - char *origin_fullpath; /* \HOST\SHARE[OPTIONAL PATH] */ /* randomly generated 128-bit number for indexing dfs mount groups in referral cache */ uuid_t dfs_mount_id; /* diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index a97ed30843cf..1ab72c3d0bff 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -693,6 +693,19 @@ struct TCP_Server_Info { #endif #ifdef CONFIG_CIFS_DFS_UPCALL bool is_dfs_conn; /* if a dfs connection */ + struct mutex refpath_lock; /* protects leaf_fullpath */ + /* + * Canonical DFS full paths that were used to chase referrals in mount and reconnect. + * + * origin_fullpath: first or original referral path + * leaf_fullpath: last referral path (might be changed due to nested links in reconnect) + * + * current_fullpath: pointer to either origin_fullpath or leaf_fullpath + * NOTE: cannot be accessed outside cifs_reconnect() and smb2_reconnect() + * + * format: \HOST\SHARE[OPTIONAL PATH] + */ + char *origin_fullpath, *leaf_fullpath, *current_fullpath; #endif };
@@ -1097,7 +1110,6 @@ struct cifs_tcon { struct cached_fid crfid; /* Cached root fid */ /* BB add field for back pointer to sb struct(s)? */ #ifdef CONFIG_CIFS_DFS_UPCALL - char *dfs_path; /* canonical DFS path */ struct list_head ulist; /* cache update list */ #endif }; @@ -1950,4 +1962,14 @@ static inline bool is_tcon_dfs(struct cifs_tcon *tcon) tcon->share_flags & (SHI1005_FLAGS_DFS | SHI1005_FLAGS_DFS_ROOT); }
+static inline bool cifs_is_referral_server(struct cifs_tcon *tcon, + const struct dfs_info3_param *ref) +{ + /* + * Check if all targets are capable of handling DFS referrals as per + * MS-DFSC 2.2.4 RESP_GET_DFS_REFERRAL. + */ + return is_tcon_dfs(tcon) || (ref && (ref->flags & DFSREF_REFERRAL_SERVER)); +} + #endif /* _CIFS_GLOB_H */ diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h index d0f85b666662..b2697356b5e7 100644 --- a/fs/cifs/cifsproto.h +++ b/fs/cifs/cifsproto.h @@ -607,7 +607,7 @@ int smb2_parse_query_directory(struct cifs_tcon *tcon, struct kvec *rsp_iov,
struct super_block *cifs_get_tcp_super(struct TCP_Server_Info *server); void cifs_put_tcp_super(struct super_block *sb); -int update_super_prepath(struct cifs_tcon *tcon, char *prefix); +int cifs_update_super_prepath(struct cifs_sb_info *cifs_sb, char *prefix); char *extract_hostname(const char *unc); char *extract_sharename(const char *unc);
@@ -634,4 +634,7 @@ static inline int cifs_create_options(struct cifs_sb_info *cifs_sb, int options) return options; }
+struct super_block *cifs_get_tcon_super(struct cifs_tcon *tcon); +void cifs_put_tcon_super(struct super_block *sb); + #endif /* _CIFSPROTO_H */ diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 5d87d5c01762..902eb8a5afd2 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -61,6 +61,20 @@ extern bool disable_legacy_dialects; /* Drop the connection to not overload the server */ #define NUM_STATUS_IO_TIMEOUT 5
+struct mount_ctx { + struct cifs_sb_info *cifs_sb; + struct smb3_fs_context *fs_ctx; + unsigned int xid; + struct TCP_Server_Info *server; + struct cifs_ses *ses; + struct cifs_tcon *tcon; +#ifdef CONFIG_CIFS_DFS_UPCALL + struct cifs_ses *root_ses; + uuid_t mount_id; + char *origin_fullpath, *leaf_fullpath; +#endif +}; + static int ip_connect(struct TCP_Server_Info *server); static int generic_ip_connect(struct TCP_Server_Info *server); static void tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink); @@ -303,14 +317,68 @@ static int __cifs_reconnect(struct TCP_Server_Info *server) }
#ifdef CONFIG_CIFS_DFS_UPCALL -static int reconnect_dfs_server(struct TCP_Server_Info *server, struct cifs_sb_info *cifs_sb) +static int __reconnect_target_unlocked(struct TCP_Server_Info *server, const char *target) +{ + int rc; + char *hostname; + + if (!cifs_swn_set_server_dstaddr(server)) { + if (server->hostname != target) { + hostname = extract_hostname(target); + if (!IS_ERR(hostname)) { + kfree(server->hostname); + server->hostname = hostname; + } else { + cifs_dbg(FYI, "%s: couldn't extract hostname or address from dfs target: %ld\n", + __func__, PTR_ERR(hostname)); + cifs_dbg(FYI, "%s: default to last target server: %s\n", __func__, + server->hostname); + } + } + /* resolve the hostname again to make sure that IP address is up-to-date. */ + rc = reconn_set_ipaddr_from_hostname(server); + cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc); + } + /* Reconnect the socket */ + if (cifs_rdma_enabled(server)) + rc = smbd_reconnect(server); + else + rc = generic_ip_connect(server); + + return rc; +} + +static int reconnect_target_unlocked(struct TCP_Server_Info *server, struct dfs_cache_tgt_list *tl, + struct dfs_cache_tgt_iterator **target_hint) +{ + int rc; + struct dfs_cache_tgt_iterator *tit; + + *target_hint = NULL; + + /* If dfs target list is empty, then reconnect to last server */ + tit = dfs_cache_get_tgt_iterator(tl); + if (!tit) + return __reconnect_target_unlocked(server, server->hostname); + + /* Otherwise, try every dfs target in @tl */ + for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) { + rc = __reconnect_target_unlocked(server, dfs_cache_get_tgt_name(tit)); + if (!rc) { + *target_hint = tit; + break; + } + } + return rc; +} + +static int reconnect_dfs_server(struct TCP_Server_Info *server) { int rc = 0; - const char *refpath = cifs_sb->origin_fullpath + 1; + const char *refpath = server->current_fullpath + 1; struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl); - struct dfs_cache_tgt_iterator *tit = NULL; - int num_targets = 1; - char *hostname; + struct dfs_cache_tgt_iterator *target_hint = NULL; + int num_targets = 0;
/* * Determine the number of dfs targets the referral path in @cifs_sb resolves to. @@ -320,11 +388,10 @@ static int reconnect_dfs_server(struct TCP_Server_Info *server, struct cifs_sb_i * through /proc/fs/cifs/dfscache or the target list is empty due to server settings after * refreshing the referral, so, in this case, default it to 1. */ - if (!dfs_cache_noreq_find(refpath, NULL, &tl)) { + if (!dfs_cache_noreq_find(refpath, NULL, &tl)) num_targets = dfs_cache_get_nr_tgts(&tl); - if (!num_targets) - num_targets = 1; - } + if (!num_targets) + num_targets = 1;
if (!cifs_tcp_ses_needs_reconnect(server, num_targets)) return 0; @@ -332,51 +399,17 @@ static int reconnect_dfs_server(struct TCP_Server_Info *server, struct cifs_sb_i cifs_mark_tcp_ses_conns_for_reconnect(server);
do { - /* Get next dfs target from target list (if any) */ - if (!tit) - tit = dfs_cache_get_tgt_iterator(&tl); - else - tit = dfs_cache_get_next_tgt(&tl, tit); - try_to_freeze(); mutex_lock(&server->srv_mutex);
- if (!cifs_swn_set_server_dstaddr(server)) { - /* - * If any dfs target was selected, then update @server with either a - * hostname or an address. - */ - if (tit) { - hostname = extract_hostname(dfs_cache_get_tgt_name(tit)); - if (!IS_ERR(hostname)) { - kfree(server->hostname); - server->hostname = hostname; - } else { - cifs_dbg(FYI, "%s: couldn't extract hostname or address from dfs target: %ld\n", - __func__, PTR_ERR(hostname)); - cifs_dbg(FYI, "%s: default to last target server: %s\n", - __func__, server->hostname); - } - } - /* resolve the hostname again to make sure that IP address is up-to-date. */ - rc = reconn_set_ipaddr_from_hostname(server); - cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc); - } - - /* Reconnect the socket */ - if (cifs_rdma_enabled(server)) - rc = smbd_reconnect(server); - else - rc = generic_ip_connect(server); - + rc = reconnect_target_unlocked(server, &tl, &target_hint); if (rc) { - /* Failed to reconnect socket. Retry next dfs target. */ + /* Failed to reconnect socket */ mutex_unlock(&server->srv_mutex); cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc); msleep(3000); continue; } - /* * Socket was created. Update tcp session status to CifsNeedNegotiate so that a * process waiting for reconnect will know it needs to re-establish session and tcon @@ -392,8 +425,8 @@ static int reconnect_dfs_server(struct TCP_Server_Info *server, struct cifs_sb_i mutex_unlock(&server->srv_mutex); } while (server->tcpStatus == CifsNeedReconnect);
- if (tit) - dfs_cache_noreq_update_tgthint(refpath, tit); + if (target_hint) + dfs_cache_noreq_update_tgthint(refpath, target_hint);
dfs_cache_free_tgts(&tl);
@@ -407,38 +440,15 @@ static int reconnect_dfs_server(struct TCP_Server_Info *server, struct cifs_sb_i
int cifs_reconnect(struct TCP_Server_Info *server) { - int rc; - struct super_block *sb; - struct cifs_sb_info *cifs_sb; - - /* - * If tcp session is not an dfs connection or it is a channel, then reconnect to last target - * server. - */ + /* If tcp session is not an dfs connection, then reconnect to last target server */ spin_lock(&cifs_tcp_ses_lock); - if (!server->is_dfs_conn || server->is_channel) { + if (!server->is_dfs_conn || !server->origin_fullpath || !server->leaf_fullpath) { spin_unlock(&cifs_tcp_ses_lock); return __cifs_reconnect(server); } spin_unlock(&cifs_tcp_ses_lock);
- /* If no superblock, then it might be an ipc connection */ - sb = cifs_get_tcp_super(server); - if (IS_ERR(sb)) - return __cifs_reconnect(server); - - /* - * Check for a referral path to look up in superblock. If unset, then simply reconnect to - * last target server. - */ - cifs_sb = CIFS_SB(sb); - if (!cifs_sb->origin_fullpath || !cifs_sb->origin_fullpath[0]) - rc = __cifs_reconnect(server); - else - rc = reconnect_dfs_server(server, cifs_sb); - - cifs_put_tcp_super(sb); - return rc; + return reconnect_dfs_server(server); } #else int cifs_reconnect(struct TCP_Server_Info *server) @@ -829,6 +839,10 @@ static void clean_demultiplex_info(struct TCP_Server_Info *server) */ }
+#ifdef CONFIG_CIFS_DFS_UPCALL + kfree(server->origin_fullpath); + kfree(server->leaf_fullpath); +#endif kfree(server);
length = atomic_dec_return(&tcpSesAllocCount); @@ -1445,6 +1459,9 @@ cifs_get_tcp_session(struct smb3_fs_context *ctx) INIT_DELAYED_WORK(&tcp_ses->resolve, cifs_resolve_server); INIT_DELAYED_WORK(&tcp_ses->reconnect, smb2_reconnect_server); mutex_init(&tcp_ses->reconnect_mutex); +#ifdef CONFIG_CIFS_DFS_UPCALL + mutex_init(&tcp_ses->refpath_lock); +#endif memcpy(&tcp_ses->srcaddr, &ctx->srcaddr, sizeof(tcp_ses->srcaddr)); memcpy(&tcp_ses->dstaddr, &ctx->dstaddr, @@ -2909,73 +2926,64 @@ int cifs_setup_cifs_sb(struct cifs_sb_info *cifs_sb) }
/* Release all succeed connections */ -static inline void mount_put_conns(struct cifs_sb_info *cifs_sb, - unsigned int xid, - struct TCP_Server_Info *server, - struct cifs_ses *ses, struct cifs_tcon *tcon) +static inline void mount_put_conns(struct mount_ctx *mnt_ctx) { int rc = 0;
- if (tcon) - cifs_put_tcon(tcon); - else if (ses) - cifs_put_smb_ses(ses); - else if (server) - cifs_put_tcp_session(server, 0); - cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_POSIX_PATHS; - free_xid(xid); + if (mnt_ctx->tcon) + cifs_put_tcon(mnt_ctx->tcon); + else if (mnt_ctx->ses) + cifs_put_smb_ses(mnt_ctx->ses); + else if (mnt_ctx->server) + cifs_put_tcp_session(mnt_ctx->server, 0); + mnt_ctx->cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_POSIX_PATHS; + free_xid(mnt_ctx->xid); }
/* Get connections for tcp, ses and tcon */ -static int mount_get_conns(struct smb3_fs_context *ctx, struct cifs_sb_info *cifs_sb, - unsigned int *xid, - struct TCP_Server_Info **nserver, - struct cifs_ses **nses, struct cifs_tcon **ntcon) +static int mount_get_conns(struct mount_ctx *mnt_ctx) { int rc = 0; - struct TCP_Server_Info *server; - struct cifs_ses *ses; - struct cifs_tcon *tcon; - - *nserver = NULL; - *nses = NULL; - *ntcon = NULL; + struct TCP_Server_Info *server = NULL; + struct cifs_ses *ses = NULL; + struct cifs_tcon *tcon = NULL; + struct smb3_fs_context *ctx = mnt_ctx->fs_ctx; + struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb; + unsigned int xid;
- *xid = get_xid(); + xid = get_xid();
/* get a reference to a tcp session */ server = cifs_get_tcp_session(ctx); if (IS_ERR(server)) { rc = PTR_ERR(server); - return rc; + server = NULL; + goto out; }
- *nserver = server; - /* get a reference to a SMB session */ ses = cifs_get_smb_ses(server, ctx); if (IS_ERR(ses)) { rc = PTR_ERR(ses); - return rc; + ses = NULL; + goto out; }
- *nses = ses; - if ((ctx->persistent == true) && (!(ses->server->capabilities & SMB2_GLOBAL_CAP_PERSISTENT_HANDLES))) { cifs_server_dbg(VFS, "persistent handles not supported by server\n"); - return -EOPNOTSUPP; + rc = -EOPNOTSUPP; + goto out; }
/* search for existing tcon to this server share */ tcon = cifs_get_tcon(ses, ctx); if (IS_ERR(tcon)) { rc = PTR_ERR(tcon); - return rc; + tcon = NULL; + goto out; }
- *ntcon = tcon; - /* if new SMB3.11 POSIX extensions are supported do not remap / and \ */ if (tcon->posix_extensions) cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_POSIX_PATHS; @@ -2986,17 +2994,19 @@ static int mount_get_conns(struct smb3_fs_context *ctx, struct cifs_sb_info *cif * reset of caps checks mount to see if unix extensions disabled * for just this mount. */ - reset_cifs_unix_caps(*xid, tcon, cifs_sb, ctx); + reset_cifs_unix_caps(xid, tcon, cifs_sb, ctx); if ((tcon->ses->server->tcpStatus == CifsNeedReconnect) && (le64_to_cpu(tcon->fsUnixInfo.Capability) & - CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)) - return -EACCES; + CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)) { + rc = -EACCES; + goto out; + } } else tcon->unix_ext = 0; /* server does not support them */
/* do not care if a following call succeed - informational */ if (!tcon->pipe && server->ops->qfs_tcon) { - server->ops->qfs_tcon(*xid, tcon, cifs_sb); + server->ops->qfs_tcon(xid, tcon, cifs_sb); if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RO_CACHE) { if (tcon->fsDevInfo.DeviceCharacteristics & cpu_to_le32(FILE_READ_ONLY_DEVICE)) @@ -3020,7 +3030,13 @@ static int mount_get_conns(struct smb3_fs_context *ctx, struct cifs_sb_info *cif (cifs_sb->ctx->rsize > server->ops->negotiate_rsize(tcon, ctx))) cifs_sb->ctx->rsize = server->ops->negotiate_rsize(tcon, ctx);
- return 0; +out: + mnt_ctx->server = server; + mnt_ctx->ses = ses; + mnt_ctx->tcon = tcon; + mnt_ctx->xid = xid; + + return rc; }
static int mount_setup_tlink(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses, @@ -3050,18 +3066,17 @@ static int mount_setup_tlink(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses, }
#ifdef CONFIG_CIFS_DFS_UPCALL -static int mount_get_dfs_conns(struct smb3_fs_context *ctx, struct cifs_sb_info *cifs_sb, - unsigned int *xid, struct TCP_Server_Info **nserver, - struct cifs_ses **nses, struct cifs_tcon **ntcon) +/* Get unique dfs connections */ +static int mount_get_dfs_conns(struct mount_ctx *mnt_ctx) { int rc;
- ctx->nosharesock = true; - rc = mount_get_conns(ctx, cifs_sb, xid, nserver, nses, ntcon); - if (*nserver) { + 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(&cifs_tcp_ses_lock); - (*nserver)->is_dfs_conn = true; + mnt_ctx->server->is_dfs_conn = true; spin_unlock(&cifs_tcp_ses_lock); } return rc; @@ -3103,190 +3118,38 @@ build_unc_path_to_root(const struct smb3_fs_context *ctx, }
/* - * expand_dfs_referral - Perform a dfs referral query and update the cifs_sb + * expand_dfs_referral - Update cifs_sb from dfs referral path * - * If a referral is found, cifs_sb->ctx->mount_options will be (re-)allocated - * to a string containing updated options for the submount. Otherwise it - * will be left untouched. - * - * Returns the rc from get_dfs_path to the caller, which can be used to - * determine whether there were referrals. + * cifs_sb->ctx->mount_options will be (re-)allocated to a string containing updated options for the + * submount. Otherwise it will be left untouched. */ -static int -expand_dfs_referral(const unsigned int xid, struct cifs_ses *ses, - struct smb3_fs_context *ctx, struct cifs_sb_info *cifs_sb, - char *ref_path) +static int expand_dfs_referral(struct mount_ctx *mnt_ctx, const char *full_path, + struct dfs_info3_param *referral) { int rc; - struct dfs_info3_param referral = {0}; - char *full_path = NULL, *mdata = NULL; - - if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) - return -EREMOTE; - - full_path = build_unc_path_to_root(ctx, cifs_sb, true); - if (IS_ERR(full_path)) - return PTR_ERR(full_path); - - rc = dfs_cache_find(xid, ses, cifs_sb->local_nls, cifs_remap(cifs_sb), - ref_path, &referral, NULL); - if (!rc) { - char *fake_devname = NULL; - - mdata = cifs_compose_mount_options(cifs_sb->ctx->mount_options, - full_path + 1, &referral, - &fake_devname); - free_dfs_info_param(&referral); - - if (IS_ERR(mdata)) { - rc = PTR_ERR(mdata); - mdata = NULL; - } else { - /* - * We can not clear out the whole structure since we - * no longer have an explicit function to parse - * a mount-string. Instead we need to clear out the - * individual fields that are no longer valid. - */ - kfree(ctx->prepath); - ctx->prepath = NULL; - rc = cifs_setup_volume_info(ctx, mdata, fake_devname); - } - kfree(fake_devname); - kfree(cifs_sb->ctx->mount_options); - cifs_sb->ctx->mount_options = mdata; - } - kfree(full_path); - return rc; -} - -static int get_next_dfs_tgt(struct dfs_cache_tgt_list *tgt_list, - struct dfs_cache_tgt_iterator **tgt_it) -{ - if (!*tgt_it) - *tgt_it = dfs_cache_get_tgt_iterator(tgt_list); - else - *tgt_it = dfs_cache_get_next_tgt(tgt_list, *tgt_it); - return !*tgt_it ? -EHOSTDOWN : 0; -} - -static int update_vol_info(const struct dfs_cache_tgt_iterator *tgt_it, - struct smb3_fs_context *fake_ctx, struct smb3_fs_context *ctx) -{ - const char *tgt = dfs_cache_get_tgt_name(tgt_it); - int len = strlen(tgt) + 2; - char *new_unc; - - new_unc = kmalloc(len, GFP_KERNEL); - if (!new_unc) - return -ENOMEM; - scnprintf(new_unc, len, "\%s", tgt); - - kfree(ctx->UNC); - ctx->UNC = new_unc; - - if (fake_ctx->prepath) { - kfree(ctx->prepath); - ctx->prepath = fake_ctx->prepath; - fake_ctx->prepath = NULL; - } - memcpy(&ctx->dstaddr, &fake_ctx->dstaddr, sizeof(ctx->dstaddr)); - - return 0; -} - -static int do_dfs_failover(const char *path, const char *full_path, struct cifs_sb_info *cifs_sb, - struct smb3_fs_context *ctx, struct cifs_ses *root_ses, - unsigned int *xid, struct TCP_Server_Info **server, - struct cifs_ses **ses, struct cifs_tcon **tcon) -{ - int rc; - char *npath = NULL; - struct dfs_cache_tgt_list tgt_list = DFS_CACHE_TGT_LIST_INIT(tgt_list); - struct dfs_cache_tgt_iterator *tgt_it = NULL; - struct smb3_fs_context tmp_ctx = {NULL}; - - if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) - return -EOPNOTSUPP; - - npath = dfs_cache_canonical_path(path, cifs_sb->local_nls, cifs_remap(cifs_sb)); - if (IS_ERR(npath)) - return PTR_ERR(npath); - - cifs_dbg(FYI, "%s: path=%s full_path=%s\n", __func__, npath, full_path); - - rc = dfs_cache_noreq_find(npath, NULL, &tgt_list); - if (rc) - goto out; - /* - * We use a 'tmp_ctx' here because we need pass it down to the mount_{get,put} functions to - * test connection against new DFS targets. - */ - rc = smb3_fs_context_dup(&tmp_ctx, ctx); - if (rc) - goto out; - - for (;;) { - struct dfs_info3_param ref = {0}; - char *fake_devname = NULL, *mdata = NULL; - - /* Get next DFS target server - if any */ - rc = get_next_dfs_tgt(&tgt_list, &tgt_it); - if (rc) - break; - - rc = dfs_cache_get_tgt_referral(npath, tgt_it, &ref); - if (rc) - break; - - cifs_dbg(FYI, "%s: old ctx: UNC=%s prepath=%s\n", __func__, tmp_ctx.UNC, - tmp_ctx.prepath); - - mdata = cifs_compose_mount_options(cifs_sb->ctx->mount_options, full_path + 1, &ref, - &fake_devname); - free_dfs_info_param(&ref); - - if (IS_ERR(mdata)) { - rc = PTR_ERR(mdata); - mdata = NULL; - } else - rc = cifs_setup_volume_info(&tmp_ctx, mdata, fake_devname); - - kfree(mdata); - kfree(fake_devname); - - if (rc) - break; - - cifs_dbg(FYI, "%s: new ctx: UNC=%s prepath=%s\n", __func__, tmp_ctx.UNC, - tmp_ctx.prepath); - - mount_put_conns(cifs_sb, *xid, *server, *ses, *tcon); - rc = mount_get_dfs_conns(&tmp_ctx, cifs_sb, xid, server, ses, tcon); - if (!rc || (*server && *ses)) { - /* - * We were able to connect to new target server. Update current context with - * new target server. - */ - rc = update_vol_info(tgt_it, &tmp_ctx, ctx); - break; - } - } - if (!rc) { - cifs_dbg(FYI, "%s: final ctx: UNC=%s prepath=%s\n", __func__, tmp_ctx.UNC, - tmp_ctx.prepath); + struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb; + struct smb3_fs_context *ctx = mnt_ctx->fs_ctx; + char *fake_devname = NULL, *mdata = NULL; + + mdata = cifs_compose_mount_options(cifs_sb->ctx->mount_options, full_path + 1, referral, + &fake_devname); + if (IS_ERR(mdata)) { + rc = PTR_ERR(mdata); + mdata = NULL; + } else { /* - * Update DFS target hint in DFS referral cache with the target server we - * successfully reconnected to. + * We can not clear out the whole structure since we no longer have an explicit + * function to parse a mount-string. Instead we need to clear out the individual + * fields that are no longer valid. */ - rc = dfs_cache_update_tgthint(*xid, root_ses ? root_ses : *ses, cifs_sb->local_nls, - cifs_remap(cifs_sb), path, tgt_it); + kfree(ctx->prepath); + ctx->prepath = NULL; + rc = cifs_setup_volume_info(ctx, mdata, fake_devname); } + kfree(fake_devname); + kfree(cifs_sb->ctx->mount_options); + cifs_sb->ctx->mount_options = mdata;
-out: - kfree(npath); - smb3_cleanup_fs_context_contents(&tmp_ctx); - dfs_cache_free_tgts(&tgt_list); return rc; } #endif @@ -3393,12 +3256,14 @@ cifs_are_all_path_components_accessible(struct TCP_Server_Info *server, * Check if path is remote (e.g. a DFS share). Return -EREMOTE if it is, * otherwise 0. */ -static int is_path_remote(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx, - const unsigned int xid, - struct TCP_Server_Info *server, - struct cifs_tcon *tcon) +static int is_path_remote(struct mount_ctx *mnt_ctx) { int rc; + struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb; + struct TCP_Server_Info *server = mnt_ctx->server; + unsigned int xid = mnt_ctx->xid; + struct cifs_tcon *tcon = mnt_ctx->tcon; + struct smb3_fs_context *ctx = mnt_ctx->fs_ctx; char *full_path;
if (!server->ops->is_path_accessible) @@ -3436,280 +3301,289 @@ static int is_path_remote(struct cifs_sb_info *cifs_sb, struct smb3_fs_context * }
#ifdef CONFIG_CIFS_DFS_UPCALL -static void set_root_ses(struct cifs_sb_info *cifs_sb, const uuid_t *mount_id, struct cifs_ses *ses, - struct cifs_ses **root_ses) +static void set_root_ses(struct mount_ctx *mnt_ctx) { - if (ses) { + if (mnt_ctx->ses) { spin_lock(&cifs_tcp_ses_lock); - ses->ses_count++; + mnt_ctx->ses->ses_count++; spin_unlock(&cifs_tcp_ses_lock); - dfs_cache_add_refsrv_session(mount_id, ses); + dfs_cache_add_refsrv_session(&mnt_ctx->mount_id, mnt_ctx->ses); } - *root_ses = ses; + mnt_ctx->root_ses = mnt_ctx->ses; }
-/* Set up next dfs prefix path in @dfs_path */ -static int next_dfs_prepath(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx, - const unsigned int xid, struct TCP_Server_Info *server, - struct cifs_tcon *tcon, char **dfs_path) +static int is_dfs_mount(struct mount_ctx *mnt_ctx, bool *isdfs, struct dfs_cache_tgt_list *root_tl) { - char *path, *npath; - int added_treename = is_tcon_dfs(tcon); int rc; + struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb; + struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
- path = cifs_build_path_to_root(ctx, cifs_sb, tcon, added_treename); - if (!path) - return -ENOMEM; + *isdfs = true;
- rc = is_path_remote(cifs_sb, ctx, xid, server, tcon); - if (rc == -EREMOTE) { - struct smb3_fs_context v = {NULL}; - /* if @path contains a tree name, skip it in the prefix path */ - if (added_treename) { - rc = smb3_parse_devname(path, &v); - if (rc) - goto out; - npath = build_unc_path_to_root(&v, cifs_sb, true); - smb3_cleanup_fs_context_contents(&v); - } else { - v.UNC = ctx->UNC; - v.prepath = path + 1; - npath = build_unc_path_to_root(&v, cifs_sb, 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; +}
- if (IS_ERR(npath)) { - rc = PTR_ERR(npath); - goto out; - } +static int connect_dfs_target(struct 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; + char *oldmnt = cifs_sb->ctx->mount_options;
- kfree(*dfs_path); - *dfs_path = npath; - rc = -EREMOTE; + rc = dfs_cache_get_tgt_referral(ref_path, tit, &ref); + if (rc) + goto out; + + rc = expand_dfs_referral(mnt_ctx, full_path, &ref); + if (rc) + goto out; + + /* Connect to new target only if we were redirected (e.g. mount options changed) */ + if (oldmnt != cifs_sb->ctx->mount_options) { + 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: - kfree(path); + free_dfs_info_param(&ref); return rc; }
-/* Check if resolved targets can handle any DFS referrals */ -static int is_referral_server(const char *ref_path, struct cifs_sb_info *cifs_sb, - struct cifs_tcon *tcon, bool *ref_server) +static int connect_dfs_root(struct mount_ctx *mnt_ctx, struct dfs_cache_tgt_list *root_tl) { int rc; - struct dfs_info3_param ref = {0}; + 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;
- cifs_dbg(FYI, "%s: ref_path=%s\n", __func__, ref_path); + /* 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);
- if (is_tcon_dfs(tcon)) { - *ref_server = true; - } else { - char *npath; + full_path = build_unc_path_to_root(ctx, cifs_sb, true); + if (IS_ERR(full_path)) + return PTR_ERR(full_path);
- npath = dfs_cache_canonical_path(ref_path, cifs_sb->local_nls, cifs_remap(cifs_sb)); - if (IS_ERR(npath)) - return PTR_ERR(npath); + 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; + }
- rc = dfs_cache_noreq_find(npath, &ref, NULL); - kfree(npath); - if (rc) { - cifs_dbg(VFS, "%s: dfs_cache_noreq_find: failed (rc=%d)\n", __func__, rc); - return rc; + /* 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; } - cifs_dbg(FYI, "%s: ref.flags=0x%x\n", __func__, ref.flags); - /* - * Check if all targets are capable of handling DFS referrals as per - * MS-DFSC 2.2.4 RESP_GET_DFS_REFERRAL. - */ - *ref_server = !!(ref.flags & DFSREF_REFERRAL_SERVER); - free_dfs_info_param(&ref); } - return 0; + +out: + kfree(full_path); + return rc; }
-int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx) +static int __follow_dfs_link(struct mount_ctx *mnt_ctx) { - int rc = 0; - unsigned int xid; - struct TCP_Server_Info *server = NULL; - struct cifs_ses *ses = NULL, *root_ses = NULL; - struct cifs_tcon *tcon = NULL; - int count = 0; - uuid_t mount_id = {0}; - char *ref_path = NULL, *full_path = NULL; - char *oldmnt = NULL; - bool ref_server = false; + 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;
- rc = mount_get_conns(ctx, cifs_sb, &xid, &server, &ses, &tcon); - /* - * 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(xid, ses, cifs_sb->local_nls, cifs_remap(cifs_sb), ctx->UNC + 1, NULL, - NULL)) { - if (rc) - goto error; - /* Check if it is fully accessible and then mount it */ - rc = is_path_remote(cifs_sb, ctx, xid, server, tcon); - if (!rc) - goto out; - if (rc != -EREMOTE) - goto error; + 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; }
- mount_put_conns(cifs_sb, xid, server, ses, tcon); - /* - * Ignore error check here because we may failover to other targets from cached a - * referral. - */ - (void)mount_get_dfs_conns(ctx, cifs_sb, &xid, &server, &ses, &tcon); + /* 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;
- /* Get path of DFS root */ - ref_path = build_unc_path_to_root(ctx, cifs_sb, false); - if (IS_ERR(ref_path)) { - rc = PTR_ERR(ref_path); - ref_path = NULL; - goto error; + /* Try all dfs link targets */ + 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); + break; + } + } + +out: + kfree(full_path); + dfs_cache_free_tgts(&tl); + return rc; +} + +static int follow_dfs_link(struct 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; }
- uuid_gen(&mount_id); - set_root_ses(cifs_sb, &mount_id, ses, &root_ses); do { - /* Save full path of last DFS path we used to resolve final target server */ - kfree(full_path); - full_path = build_unc_path_to_root(ctx, cifs_sb, !!count); - if (IS_ERR(full_path)) { - rc = PTR_ERR(full_path); - full_path = NULL; - break; - } - /* Chase referral */ - oldmnt = cifs_sb->ctx->mount_options; - rc = expand_dfs_referral(xid, root_ses, ctx, cifs_sb, ref_path + 1); - if (rc) + rc = __follow_dfs_link(mnt_ctx); + if (!rc || rc != -EREMOTE) break; - /* Connect to new DFS target only if we were redirected */ - if (oldmnt != cifs_sb->ctx->mount_options) { - mount_put_conns(cifs_sb, xid, server, ses, tcon); - rc = mount_get_dfs_conns(ctx, cifs_sb, &xid, &server, &ses, &tcon); - } - if (rc && !server && !ses) { - /* Failed to connect. Try to connect to other targets in the referral. */ - rc = do_dfs_failover(ref_path + 1, full_path, cifs_sb, ctx, root_ses, &xid, - &server, &ses, &tcon); - } - if (rc == -EACCES || rc == -EOPNOTSUPP || !server || !ses) - break; - if (!tcon) - continue; + } while (rc = -ELOOP, ++num_links < MAX_NESTED_LINKS);
- /* Make sure that requests go through new root servers */ - rc = is_referral_server(ref_path + 1, cifs_sb, tcon, &ref_server); - if (rc) - break; - if (ref_server) - set_root_ses(cifs_sb, &mount_id, ses, &root_ses); + return rc; +}
- /* Get next dfs path and then continue chasing them if -EREMOTE */ - rc = next_dfs_prepath(cifs_sb, ctx, xid, server, tcon, &ref_path); - /* Prevent recursion on broken link referrals */ - if (rc == -EREMOTE && ++count > MAX_NESTED_LINKS) - rc = -ELOOP; - } while (rc == -EREMOTE); +/* Set up DFS referral paths for failover */ +static void setup_server_referral_paths(struct mount_ctx *mnt_ctx) +{ + struct TCP_Server_Info *server = mnt_ctx->server; + + server->origin_fullpath = mnt_ctx->origin_fullpath; + server->leaf_fullpath = mnt_ctx->leaf_fullpath; + server->current_fullpath = mnt_ctx->leaf_fullpath; + mnt_ctx->origin_fullpath = mnt_ctx->leaf_fullpath = NULL; +}
- if (rc || !tcon || !ses) +int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx) +{ + int rc; + struct 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; + + rc = is_dfs_mount(&mnt_ctx, &isdfs, &tl); + if (rc) goto error; + if (!isdfs) + goto out;
- kfree(ref_path); - /* - * Store DFS full path in both superblock and tree connect structures. - * - * For DFS root mounts, the prefix path (cifs_sb->prepath) is preserved during reconnect so - * only the root path is set in cifs_sb->origin_fullpath and tcon->dfs_path. And for DFS - * links, the prefix path is included in both and may be changed during reconnect. See - * cifs_tree_connect(). - */ - ref_path = dfs_cache_canonical_path(full_path, cifs_sb->local_nls, cifs_remap(cifs_sb)); - kfree(full_path); - full_path = NULL; + uuid_gen(&mnt_ctx.mount_id); + rc = connect_dfs_root(&mnt_ctx, &tl); + dfs_cache_free_tgts(&tl);
- if (IS_ERR(ref_path)) { - rc = PTR_ERR(ref_path); - ref_path = NULL; + if (rc) goto error; - } - cifs_sb->origin_fullpath = ref_path;
- ref_path = kstrdup(cifs_sb->origin_fullpath, GFP_KERNEL); - if (!ref_path) { - rc = -ENOMEM; + rc = is_path_remote(&mnt_ctx); + if (rc == -EREMOTE) + rc = follow_dfs_link(&mnt_ctx); + if (rc) goto error; - } - spin_lock(&cifs_tcp_ses_lock); - tcon->dfs_path = ref_path; - ref_path = NULL; - spin_unlock(&cifs_tcp_ses_lock);
+ 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). + * 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). */ cifs_autodisable_serverino(cifs_sb); /* - * Force the use of prefix path to support failover on DFS paths that - * resolve to targets that have different prefix paths. + * Force the use of prefix path to support failover on DFS paths that resolve to targets + * that have different prefix paths. */ cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH; kfree(cifs_sb->prepath); cifs_sb->prepath = ctx->prepath; ctx->prepath = NULL; - uuid_copy(&cifs_sb->dfs_mount_id, &mount_id); + uuid_copy(&cifs_sb->dfs_mount_id, &mnt_ctx.mount_id);
out: - free_xid(xid); - cifs_try_adding_channels(cifs_sb, ses); - return mount_setup_tlink(cifs_sb, ses, tcon); + free_xid(mnt_ctx.xid); + cifs_try_adding_channels(cifs_sb, mnt_ctx.ses); + return mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
error: - kfree(ref_path); - kfree(full_path); - kfree(cifs_sb->origin_fullpath); - dfs_cache_put_refsrv_sessions(&mount_id); - mount_put_conns(cifs_sb, xid, server, ses, tcon); + dfs_cache_put_refsrv_sessions(&mnt_ctx.mount_id); + kfree(mnt_ctx.origin_fullpath); + kfree(mnt_ctx.leaf_fullpath); + mount_put_conns(&mnt_ctx); return rc; } #else int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx) { int rc = 0; - unsigned int xid; - struct cifs_ses *ses; - struct cifs_tcon *tcon; - struct TCP_Server_Info *server; + struct mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
- rc = mount_get_conns(ctx, cifs_sb, &xid, &server, &ses, &tcon); + rc = mount_get_conns(&mnt_ctx); if (rc) goto error;
- if (tcon) { - rc = is_path_remote(cifs_sb, ctx, xid, server, tcon); + if (mnt_ctx.tcon) { + rc = is_path_remote(&mnt_ctx); if (rc == -EREMOTE) rc = -EOPNOTSUPP; if (rc) goto error; }
- free_xid(xid); - - return mount_setup_tlink(cifs_sb, ses, tcon); + free_xid(mnt_ctx.xid); + return mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
error: - mount_put_conns(cifs_sb, xid, server, ses, tcon); + mount_put_conns(&mnt_ctx); return rc; } #endif @@ -3877,7 +3751,6 @@ cifs_umount(struct cifs_sb_info *cifs_sb) kfree(cifs_sb->prepath); #ifdef CONFIG_CIFS_DFS_UPCALL dfs_cache_put_refsrv_sessions(&cifs_sb->dfs_mount_id); - kfree(cifs_sb->origin_fullpath); #endif call_rcu(&cifs_sb->rcu, delayed_free); } @@ -4204,104 +4077,249 @@ cifs_prune_tlinks(struct work_struct *work) }
#ifdef CONFIG_CIFS_DFS_UPCALL -int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc) +static void mark_tcon_tcp_ses_for_reconnect(struct cifs_tcon *tcon) +{ + int i; + + for (i = 0; i < tcon->ses->chan_count; i++) { + spin_lock(&GlobalMid_Lock); + if (tcon->ses->chans[i].server->tcpStatus != CifsExiting) + tcon->ses->chans[i].server->tcpStatus = CifsNeedReconnect; + spin_unlock(&GlobalMid_Lock); + } +} + +/* Update dfs referral path of superblock */ +static int update_server_fullpath(struct TCP_Server_Info *server, struct cifs_sb_info *cifs_sb, + const char *target) +{ + int rc = 0; + size_t len = strlen(target); + char *refpath, *npath; + + if (unlikely(len < 2 || *target != '\')) + return -EINVAL; + + if (target[1] == '\') { + len += 1; + refpath = kmalloc(len, GFP_KERNEL); + if (!refpath) + return -ENOMEM; + + scnprintf(refpath, len, "%s", target); + } else { + len += sizeof("\"); + refpath = kmalloc(len, GFP_KERNEL); + if (!refpath) + return -ENOMEM; + + scnprintf(refpath, len, "\%s", target); + } + + npath = dfs_cache_canonical_path(refpath, cifs_sb->local_nls, cifs_remap(cifs_sb)); + kfree(refpath); + + if (IS_ERR(npath)) { + rc = PTR_ERR(npath); + } else { + mutex_lock(&server->refpath_lock); + kfree(server->leaf_fullpath); + server->leaf_fullpath = npath; + mutex_unlock(&server->refpath_lock); + server->current_fullpath = server->leaf_fullpath; + } + return rc; +} + +static int target_share_matches_server(struct TCP_Server_Info *server, const char *tcp_host, + size_t tcp_host_len, char *share, bool *target_match) +{ + int rc = 0; + const char *dfs_host; + size_t dfs_host_len; + + *target_match = true; + extract_unc_hostname(share, &dfs_host, &dfs_host_len); + + /* Check if hostnames or addresses match */ + if (dfs_host_len != tcp_host_len || strncasecmp(dfs_host, tcp_host, dfs_host_len) != 0) { + cifs_dbg(FYI, "%s: %.*s doesn't match %.*s\n", __func__, (int)dfs_host_len, + dfs_host, (int)tcp_host_len, tcp_host); + rc = match_target_ip(server, dfs_host, dfs_host_len, target_match); + if (rc) + cifs_dbg(VFS, "%s: failed to match target ip: %d\n", __func__, rc); + } + return rc; +} + +int __tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *tcon, + struct cifs_sb_info *cifs_sb, char *tree, + struct dfs_cache_tgt_list *tl, struct dfs_info3_param *ref) { int rc; struct TCP_Server_Info *server = tcon->ses->server; const struct smb_version_operations *ops = server->ops; - struct dfs_cache_tgt_list tl; - struct dfs_cache_tgt_iterator *it = NULL; - char *tree; + struct cifs_tcon *ipc = tcon->ses->tcon_ipc; + bool islink; + char *share = NULL, *prefix = NULL; const char *tcp_host; size_t tcp_host_len; - const char *dfs_host; - size_t dfs_host_len; - char *share = NULL, *prefix = NULL; - struct dfs_info3_param ref = {0}; - bool isroot; + struct dfs_cache_tgt_iterator *tit; + bool target_match;
- tree = kzalloc(MAX_TREE_SIZE, GFP_KERNEL); - if (!tree) - return -ENOMEM; + extract_unc_hostname(server->hostname, &tcp_host, &tcp_host_len);
- /* If it is not dfs or there was no cached dfs referral, then reconnect to same share */ - if (!tcon->dfs_path || dfs_cache_noreq_find(tcon->dfs_path + 1, &ref, &tl)) { - if (tcon->ipc) { - scnprintf(tree, MAX_TREE_SIZE, "\\%s\IPC$", server->hostname); - rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc); - } else { - rc = ops->tree_connect(xid, tcon->ses, tcon->treeName, tcon, nlsc); - } + islink = ref->server_type == DFS_TYPE_LINK; + free_dfs_info_param(ref); + + tit = dfs_cache_get_tgt_iterator(tl); + if (!tit) { + rc = -ENOENT; goto out; }
- isroot = ref.server_type == DFS_TYPE_ROOT; - free_dfs_info_param(&ref); - - extract_unc_hostname(server->hostname, &tcp_host, &tcp_host_len); - - for (it = dfs_cache_get_tgt_iterator(&tl); it; it = dfs_cache_get_next_tgt(&tl, it)) { - bool target_match; + /* Try to tree connect to all dfs targets */ + for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) { + const char *target = dfs_cache_get_tgt_name(tit); + struct dfs_cache_tgt_list ntl = DFS_CACHE_TGT_LIST_INIT(ntl);
kfree(share); kfree(prefix); - share = NULL; - prefix = NULL;
- rc = dfs_cache_get_tgt_share(tcon->dfs_path + 1, it, &share, &prefix); + /* Check if share matches with tcp ses */ + rc = dfs_cache_get_tgt_share(server->current_fullpath + 1, tit, &share, &prefix); if (rc) { - cifs_dbg(VFS, "%s: failed to parse target share %d\n", - __func__, rc); - continue; + cifs_dbg(VFS, "%s: failed to parse target share: %d\n", __func__, rc); + break; }
- extract_unc_hostname(share, &dfs_host, &dfs_host_len); - - if (dfs_host_len != tcp_host_len - || strncasecmp(dfs_host, tcp_host, dfs_host_len) != 0) { - cifs_dbg(FYI, "%s: %.*s doesn't match %.*s\n", __func__, (int)dfs_host_len, - dfs_host, (int)tcp_host_len, tcp_host); + rc = target_share_matches_server(server, tcp_host, tcp_host_len, share, + &target_match); + if (rc) + break; + if (!target_match) { + rc = -EHOSTUNREACH; + continue; + }
- rc = match_target_ip(server, dfs_host, dfs_host_len, &target_match); - if (rc) { - cifs_dbg(VFS, "%s: failed to match target ip: %d\n", __func__, rc); + if (ipc->need_reconnect) { + scnprintf(tree, MAX_TREE_SIZE, "\\%s\IPC$", server->hostname); + rc = ops->tree_connect(xid, ipc->ses, tree, ipc, cifs_sb->local_nls); + if (rc) break; - } + }
- if (!target_match) { - cifs_dbg(FYI, "%s: skipping target\n", __func__); + scnprintf(tree, MAX_TREE_SIZE, "\%s", share); + if (!islink) { + rc = ops->tree_connect(xid, tcon->ses, tree, tcon, cifs_sb->local_nls); + break; + } + /* + * If no dfs referrals were returned from link target, then just do a TREE_CONNECT + * to it. Otherwise, cache the dfs referral and then mark current tcp ses for + * reconnect so either the demultiplex thread or the echo worker will reconnect to + * newly resolved target. + */ + if (dfs_cache_find(xid, tcon->ses, cifs_sb->local_nls, cifs_remap(cifs_sb), target, + ref, &ntl)) { + rc = ops->tree_connect(xid, tcon->ses, tree, tcon, cifs_sb->local_nls); + if (rc) continue; - } + rc = dfs_cache_noreq_update_tgthint(server->current_fullpath + 1, tit); + if (!rc) + rc = cifs_update_super_prepath(cifs_sb, prefix); + break; } + /* Target is another dfs share */ + rc = update_server_fullpath(server, cifs_sb, target); + dfs_cache_free_tgts(tl);
- if (tcon->ipc) { - scnprintf(tree, MAX_TREE_SIZE, "\\%s\IPC$", share); - rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc); + if (!rc) { + rc = -EREMOTE; + list_replace_init(&ntl.tl_list, &tl->tl_list); } else { - scnprintf(tree, MAX_TREE_SIZE, "\%s", share); - rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc); - /* Only handle prefix paths of DFS link targets */ - if (!rc && !isroot) { - rc = update_super_prepath(tcon, prefix); - break; - } + dfs_cache_free_tgts(&ntl); + free_dfs_info_param(ref); } - if (rc == -EREMOTE) - break; + break; }
+out: kfree(share); kfree(prefix);
- if (!rc) { - if (it) - rc = dfs_cache_noreq_update_tgthint(tcon->dfs_path + 1, it); - else - rc = -ENOENT; + return rc; +} + +int tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *tcon, + struct cifs_sb_info *cifs_sb, char *tree, + struct dfs_cache_tgt_list *tl, struct dfs_info3_param *ref) +{ + int rc; + int num_links = 0; + struct TCP_Server_Info *server = tcon->ses->server; + + do { + rc = __tree_connect_dfs_target(xid, tcon, cifs_sb, tree, tl, ref); + if (!rc || rc != -EREMOTE) + break; + } while (rc = -ELOOP, ++num_links < MAX_NESTED_LINKS); + /* + * If we couldn't tree connect to any targets from last referral path, then retry from + * original referral path. + */ + if (rc && server->current_fullpath != server->origin_fullpath) { + server->current_fullpath = server->origin_fullpath; + mark_tcon_tcp_ses_for_reconnect(tcon); } - dfs_cache_free_tgts(&tl); + + dfs_cache_free_tgts(tl); + return rc; +} + +int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc) +{ + int rc; + struct TCP_Server_Info *server = tcon->ses->server; + const struct smb_version_operations *ops = server->ops; + struct super_block *sb = NULL; + struct cifs_sb_info *cifs_sb; + struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl); + char *tree; + struct dfs_info3_param ref = {0}; + + tree = kzalloc(MAX_TREE_SIZE, GFP_KERNEL); + if (!tree) + return -ENOMEM; + + if (tcon->ipc) { + scnprintf(tree, MAX_TREE_SIZE, "\\%s\IPC$", server->hostname); + rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc); + goto out; + } + + sb = cifs_get_tcp_super(server); + if (IS_ERR(sb)) { + rc = PTR_ERR(sb); + cifs_dbg(VFS, "%s: could not find superblock: %d\n", __func__, rc); + goto out; + } + + cifs_sb = CIFS_SB(sb); + + /* If it is not dfs or there was no cached dfs referral, then reconnect to same share */ + if (!server->current_fullpath || + dfs_cache_noreq_find(server->current_fullpath + 1, &ref, &tl)) { + rc = ops->tree_connect(xid, tcon->ses, tcon->treeName, tcon, cifs_sb->local_nls); + goto out; + } + + rc = tree_connect_dfs_target(xid, tcon, cifs_sb, tree, &tl, &ref); + out: kfree(tree); + cifs_put_tcp_super(sb); + return rc; } #else diff --git a/fs/cifs/dfs_cache.c b/fs/cifs/dfs_cache.c index 283745592844..1f3efa7821a0 100644 --- a/fs/cifs/dfs_cache.c +++ b/fs/cifs/dfs_cache.c @@ -1364,9 +1364,9 @@ static void mark_for_reconnect_if_needed(struct cifs_tcon *tcon, struct dfs_cach }
/* Refresh dfs referral of tcon and mark it for reconnect if needed */ -static int refresh_tcon(struct cifs_ses **sessions, struct cifs_tcon *tcon, bool force_refresh) +static int __refresh_tcon(const char *path, struct cifs_ses **sessions, struct cifs_tcon *tcon, + bool force_refresh) { - const char *path = tcon->dfs_path + 1; struct cifs_ses *ses; struct cache_entry *ce; struct dfs_info3_param *refs = NULL; @@ -1422,6 +1422,20 @@ static int refresh_tcon(struct cifs_ses **sessions, struct cifs_tcon *tcon, bool return rc; }
+static int refresh_tcon(struct cifs_ses **sessions, struct cifs_tcon *tcon, bool force_refresh) +{ + struct TCP_Server_Info *server = tcon->ses->server; + + mutex_lock(&server->refpath_lock); + if (strcasecmp(server->leaf_fullpath, server->origin_fullpath)) + __refresh_tcon(server->leaf_fullpath + 1, sessions, tcon, force_refresh); + mutex_unlock(&server->refpath_lock); + + __refresh_tcon(server->origin_fullpath + 1, sessions, tcon, force_refresh); + + return 0; +} + /** * dfs_cache_remount_fs - remount a DFS share * @@ -1435,6 +1449,7 @@ static int refresh_tcon(struct cifs_ses **sessions, struct cifs_tcon *tcon, bool int dfs_cache_remount_fs(struct cifs_sb_info *cifs_sb) { struct cifs_tcon *tcon; + struct TCP_Server_Info *server; struct mount_group *mg; struct cifs_ses *sessions[CACHE_MAX_ENTRIES + 1] = {NULL}; int rc; @@ -1443,13 +1458,15 @@ int dfs_cache_remount_fs(struct cifs_sb_info *cifs_sb) return -EINVAL;
tcon = cifs_sb_master_tcon(cifs_sb); - if (!tcon->dfs_path) { - cifs_dbg(FYI, "%s: not a dfs tcon\n", __func__); + server = tcon->ses->server; + + if (!server->origin_fullpath) { + cifs_dbg(FYI, "%s: not a dfs mount\n", __func__); return 0; }
if (uuid_is_null(&cifs_sb->dfs_mount_id)) { - cifs_dbg(FYI, "%s: tcon has no dfs mount group id\n", __func__); + cifs_dbg(FYI, "%s: no dfs mount group id\n", __func__); return -EINVAL; }
@@ -1457,7 +1474,7 @@ int dfs_cache_remount_fs(struct cifs_sb_info *cifs_sb) mg = find_mount_group_locked(&cifs_sb->dfs_mount_id); if (IS_ERR(mg)) { mutex_unlock(&mount_group_list_lock); - cifs_dbg(FYI, "%s: tcon has ipc session to refresh referral\n", __func__); + cifs_dbg(FYI, "%s: no ipc session for refreshing referral\n", __func__); return PTR_ERR(mg); } kref_get(&mg->refcount); @@ -1498,9 +1515,12 @@ static void refresh_mounts(struct cifs_ses **sessions)
spin_lock(&cifs_tcp_ses_lock); list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) { + if (!server->is_dfs_conn) + continue; + list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) { list_for_each_entry(tcon, &ses->tcon_list, tcon_list) { - if (tcon->dfs_path) { + if (!tcon->ipc && !tcon->need_reconnect) { tcon->tc_count++; list_add_tail(&tcon->ulist, &tcons); } @@ -1510,8 +1530,16 @@ static void refresh_mounts(struct cifs_ses **sessions) spin_unlock(&cifs_tcp_ses_lock);
list_for_each_entry_safe(tcon, ntcon, &tcons, ulist) { + struct TCP_Server_Info *server = tcon->ses->server; + list_del_init(&tcon->ulist); - refresh_tcon(sessions, tcon, false); + + mutex_lock(&server->refpath_lock); + if (strcasecmp(server->leaf_fullpath, server->origin_fullpath)) + __refresh_tcon(server->leaf_fullpath + 1, sessions, tcon, false); + mutex_unlock(&server->refpath_lock); + + __refresh_tcon(server->origin_fullpath + 1, sessions, tcon, false); cifs_put_tcon(tcon); } } diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c index 699f676ded47..94143d7f58c7 100644 --- a/fs/cifs/misc.c +++ b/fs/cifs/misc.c @@ -139,9 +139,6 @@ tconInfoFree(struct cifs_tcon *buf_to_free) kfree(buf_to_free->nativeFileSystem); kfree_sensitive(buf_to_free->password); kfree(buf_to_free->crfid.fid); -#ifdef CONFIG_CIFS_DFS_UPCALL - kfree(buf_to_free->dfs_path); -#endif kfree(buf_to_free); }
@@ -1299,69 +1296,20 @@ int match_target_ip(struct TCP_Server_Info *server, return rc; }
-static void tcon_super_cb(struct super_block *sb, void *arg) +int cifs_update_super_prepath(struct cifs_sb_info *cifs_sb, char *prefix) { - struct super_cb_data *sd = arg; - struct cifs_tcon *tcon = sd->data; - struct cifs_sb_info *cifs_sb; - - if (sd->sb) - return; - - cifs_sb = CIFS_SB(sb); - if (tcon->dfs_path && cifs_sb->origin_fullpath && - !strcasecmp(tcon->dfs_path, cifs_sb->origin_fullpath)) - sd->sb = sb; -} - -static inline struct super_block *cifs_get_tcon_super(struct cifs_tcon *tcon) -{ - return __cifs_get_super(tcon_super_cb, tcon); -} - -static inline void cifs_put_tcon_super(struct super_block *sb) -{ - __cifs_put_super(sb); -} -#else -static inline struct super_block *cifs_get_tcon_super(struct cifs_tcon *tcon) -{ - return ERR_PTR(-EOPNOTSUPP); -} - -static inline void cifs_put_tcon_super(struct super_block *sb) -{ -} -#endif - -int update_super_prepath(struct cifs_tcon *tcon, char *prefix) -{ - struct super_block *sb; - struct cifs_sb_info *cifs_sb; - int rc = 0; - - sb = cifs_get_tcon_super(tcon); - if (IS_ERR(sb)) - return PTR_ERR(sb); - - cifs_sb = CIFS_SB(sb); - kfree(cifs_sb->prepath);
if (prefix && *prefix) { cifs_sb->prepath = kstrdup(prefix, GFP_ATOMIC); - if (!cifs_sb->prepath) { - rc = -ENOMEM; - goto out; - } + if (!cifs_sb->prepath) + return -ENOMEM;
convert_delimiter(cifs_sb->prepath, CIFS_DIR_SEP(cifs_sb)); } else cifs_sb->prepath = NULL;
cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH; - -out: - cifs_put_tcon_super(sb); - return rc; + return 0; } +#endif diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index 53e87466e3b2..5e6526c201fe 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -2869,6 +2869,7 @@ smb2_get_dfs_refer(const unsigned int xid, struct cifs_ses *ses, struct fsctl_get_dfs_referral_req *dfs_req = NULL; struct get_dfs_referral_rsp *dfs_rsp = NULL; u32 dfs_req_size = 0, dfs_rsp_size = 0; + int retry_count = 0;
cifs_dbg(FYI, "%s: path: %s\n", __func__, search_name);
@@ -2920,11 +2921,14 @@ smb2_get_dfs_refer(const unsigned int xid, struct cifs_ses *ses, true /* is_fsctl */, (char *)dfs_req, dfs_req_size, CIFSMaxBufSize, (char **)&dfs_rsp, &dfs_rsp_size); - } while (rc == -EAGAIN); + if (!is_retryable_error(rc)) + break; + usleep_range(512, 2048); + } while (++retry_count < 5);
if (rc) { - if ((rc != -ENOENT) && (rc != -EOPNOTSUPP)) - cifs_tcon_dbg(VFS, "ioctl error in %s rc=%d\n", __func__, rc); + if (!is_retryable_error(rc) && rc != -ENOENT && rc != -EOPNOTSUPP) + cifs_tcon_dbg(VFS, "%s: ioctl error: rc=%d\n", __func__, rc); goto out; }
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 8aa0372141f5..c0ea2813978b 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -156,7 +156,11 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon, if (tcon == NULL) return 0;
- if (smb2_command == SMB2_TREE_CONNECT) + /* + * Need to also skip SMB2_IOCTL because it is used for checking nested dfs links in + * cifs_tree_connect(). + */ + if (smb2_command == SMB2_TREE_CONNECT || smb2_command == SMB2_IOCTL) return 0;
if (tcon->tidStatus == CifsExiting) {