From: Paulo Alcantara pc@manguebit.com
[ Upstream commit 3ae872de410751fe5e629e04da491a632d95201c ]
When having two DFS root mounts that are connected to same namespace, same mount options but different prefix paths, we can't really use the shared @server->origin_fullpath when chasing DFS links in them.
Move the origin_fullpath field to cifs_tcon structure so when having shared DFS root mounts with different prefix paths, and we need to chase any DFS links, dfs_get_automount_devname() will pick up the correct full path out of the @tcon that will be used for the new mount.
Before patch
mount.cifs //dom/dfs/dir /mnt/1 -o ... mount.cifs //dom/dfs /mnt/2 -o ... # shared server, ses, tcon # server: origin_fullpath=//dom/dfs/dir
# @server->origin_fullpath + '/dir/link1' $ ls /mnt/2/dir/link1 ls: cannot open directory '/mnt/2/dir/link1': No such file or directory
After patch
mount.cifs //dom/dfs/dir /mnt/1 -o ... mount.cifs //dom/dfs /mnt/2 -o ... # shared server & ses # tcon_1: origin_fullpath=//dom/dfs/dir # tcon_2: origin_fullpath=//dom/dfs
# @tcon_2->origin_fullpath + '/dir/link1' $ ls /mnt/2/dir/link1 dir0 dir1 dir10 dir3 dir5 dir6 dir7 dir9 target2_file.txt tsub
Fixes: 8e3554150d6c ("cifs: fix sharing of DFS connections") Signed-off-by: Paulo Alcantara (SUSE) pc@manguebit.com Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/smb/client/cifs_debug.c | 16 +++++---- fs/smb/client/cifsglob.h | 10 +++--- fs/smb/client/cifsproto.h | 2 +- fs/smb/client/connect.c | 70 ++++++++++++++++++++++---------------- fs/smb/client/dfs.c | 55 ++++++++++++------------------ fs/smb/client/dfs.h | 19 +++++------ fs/smb/client/dfs_cache.c | 8 +++-- fs/smb/client/misc.c | 38 ++++++++++++++++----- 8 files changed, 118 insertions(+), 100 deletions(-)
diff --git a/fs/smb/client/cifs_debug.c b/fs/smb/client/cifs_debug.c index b279f745466e4..ed0f71137584f 100644 --- a/fs/smb/client/cifs_debug.c +++ b/fs/smb/client/cifs_debug.c @@ -122,6 +122,12 @@ static void cifs_debug_tcon(struct seq_file *m, struct cifs_tcon *tcon) seq_puts(m, " nosparse"); if (tcon->need_reconnect) seq_puts(m, "\tDISCONNECTED "); + spin_lock(&tcon->tc_lock); + if (tcon->origin_fullpath) { + seq_printf(m, "\n\tDFS origin fullpath: %s", + tcon->origin_fullpath); + } + spin_unlock(&tcon->tc_lock); seq_putc(m, '\n'); }
@@ -427,13 +433,9 @@ static int cifs_debug_data_proc_show(struct seq_file *m, void *v) seq_printf(m, "\nIn Send: %d In MaxReq Wait: %d", atomic_read(&server->in_send), atomic_read(&server->num_waiters)); - if (IS_ENABLED(CONFIG_CIFS_DFS_UPCALL)) { - if (server->origin_fullpath) - seq_printf(m, "\nDFS origin full path: %s", - server->origin_fullpath); - if (server->leaf_fullpath) - seq_printf(m, "\nDFS leaf full path: %s", - server->leaf_fullpath); + if (server->leaf_fullpath) { + seq_printf(m, "\nDFS leaf full path: %s", + server->leaf_fullpath); }
seq_printf(m, "\n\n\tSessions: "); diff --git a/fs/smb/client/cifsglob.h b/fs/smb/client/cifsglob.h index b212a4e16b39b..ca2da713c5fe9 100644 --- a/fs/smb/client/cifsglob.h +++ b/fs/smb/client/cifsglob.h @@ -736,23 +736,20 @@ struct TCP_Server_Info { #endif struct mutex refpath_lock; /* protects leaf_fullpath */ /* - * origin_fullpath: Canonical copy of smb3_fs_context::source. - * It is used for matching existing DFS tcons. - * * leaf_fullpath: Canonical DFS referral path related to this * connection. * It is used in DFS cache refresher, reconnect and may * change due to nested DFS links. * - * Both protected by @refpath_lock and @srv_lock. The @refpath_lock is - * mosly used for not requiring a copy of @leaf_fullpath when getting + * Protected by @refpath_lock and @srv_lock. The @refpath_lock is + * mostly used for not requiring a copy of @leaf_fullpath when getting * cached or new DFS referrals (which might also sleep during I/O). * While @srv_lock is held for making string and NULL comparions against * both fields as in mount(2) and cache refresh. * * format: \HOST\SHARE[\OPTIONAL PATH] */ - char *origin_fullpath, *leaf_fullpath; + char *leaf_fullpath; };
static inline bool is_smb1(struct TCP_Server_Info *server) @@ -1205,6 +1202,7 @@ struct cifs_tcon { struct delayed_work dfs_cache_work; #endif struct delayed_work query_interfaces; /* query interfaces workqueue job */ + char *origin_fullpath; /* canonical copy of smb3_fs_context::source */ };
/* diff --git a/fs/smb/client/cifsproto.h b/fs/smb/client/cifsproto.h index d127aded2f287..94ab6402965c5 100644 --- a/fs/smb/client/cifsproto.h +++ b/fs/smb/client/cifsproto.h @@ -650,7 +650,7 @@ int smb2_parse_query_directory(struct cifs_tcon *tcon, struct kvec *rsp_iov, int resp_buftype, struct cifs_search_info *srch_inf);
-struct super_block *cifs_get_tcp_super(struct TCP_Server_Info *server); +struct super_block *cifs_get_dfs_tcon_super(struct cifs_tcon *tcon); void cifs_put_tcp_super(struct super_block *sb); int cifs_update_super_prepath(struct cifs_sb_info *cifs_sb, char *prefix); char *extract_hostname(const char *unc); diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c index 9d16626e7a669..d9f0b3b94f007 100644 --- a/fs/smb/client/connect.c +++ b/fs/smb/client/connect.c @@ -996,7 +996,6 @@ static void clean_demultiplex_info(struct TCP_Server_Info *server) */ }
- kfree(server->origin_fullpath); kfree(server->leaf_fullpath); kfree(server);
@@ -1436,7 +1435,9 @@ match_security(struct TCP_Server_Info *server, struct smb3_fs_context *ctx) }
/* 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 match_super) { struct sockaddr *addr = (struct sockaddr *)&ctx->dstaddr;
@@ -1467,36 +1468,38 @@ static int match_server(struct TCP_Server_Info *server, struct smb3_fs_context * (struct sockaddr *)&server->srcaddr)) return 0; /* - * - Match for an DFS tcon (@server->origin_fullpath). - * - Match for an DFS root server connection (@server->leaf_fullpath). - * - If none of the above and @ctx->leaf_fullpath is set, then - * it is a new DFS connection. - * - If 'nodfs' mount option was passed, then match only connections - * that have no DFS referrals set - * (e.g. can't failover to other targets). + * When matching cifs.ko superblocks (@match_super == true), we can't + * really match either @server->leaf_fullpath or @server->dstaddr + * directly since this @server might belong to a completely different + * server -- in case of domain-based DFS referrals or DFS links -- as + * provided earlier by mount(2) through 'source' and 'ip' options. + * + * Otherwise, match the DFS referral in @server->leaf_fullpath or the + * destination address in @server->dstaddr. + * + * When using 'nodfs' mount option, we avoid sharing it with DFS + * connections as they might failover. */ - if (!ctx->nodfs) { - if (ctx->source && server->origin_fullpath) { - if (!dfs_src_pathname_equal(ctx->source, - server->origin_fullpath)) + if (!match_super) { + if (!ctx->nodfs) { + if (server->leaf_fullpath) { + if (!ctx->leaf_fullpath || + strcasecmp(server->leaf_fullpath, + ctx->leaf_fullpath)) + return 0; + } else if (ctx->leaf_fullpath) { return 0; + } } else if (server->leaf_fullpath) { - if (!ctx->leaf_fullpath || - strcasecmp(server->leaf_fullpath, - ctx->leaf_fullpath)) - return 0; - } else if (ctx->leaf_fullpath) { return 0; } - } else if (server->origin_fullpath || server->leaf_fullpath) { - return 0; }
/* * Match for a regular connection (address/hostname/port) which has no * DFS referrals set. */ - if (!server->origin_fullpath && !server->leaf_fullpath && + if (!server->leaf_fullpath && (strcasecmp(server->hostname, ctx->server_hostname) || !match_server_address(server, addr) || !match_port(server, addr))) @@ -1532,7 +1535,8 @@ cifs_find_tcp_session(struct smb3_fs_context *ctx) * 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; } @@ -2320,10 +2324,16 @@ static int match_tcon(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
if (tcon->status == TID_EXITING) return 0; - /* Skip UNC validation when matching DFS connections or superblocks */ - if (!server->origin_fullpath && !server->leaf_fullpath && - strncmp(tcon->tree_name, ctx->UNC, MAX_TREE_SIZE)) + + if (tcon->origin_fullpath) { + if (!ctx->source || + !dfs_src_pathname_equal(ctx->source, + tcon->origin_fullpath)) + return 0; + } else if (!server->leaf_fullpath && + strncmp(tcon->tree_name, ctx->UNC, MAX_TREE_SIZE)) { return 0; + } if (tcon->seal != ctx->seal) return 0; if (tcon->snapshot_time != ctx->snapshot_time) @@ -2722,7 +2732,7 @@ compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data) }
static int match_prepath(struct super_block *sb, - struct TCP_Server_Info *server, + struct cifs_tcon *tcon, struct cifs_mnt_data *mnt_data) { struct smb3_fs_context *ctx = mnt_data->ctx; @@ -2733,8 +2743,8 @@ static int match_prepath(struct super_block *sb, bool new_set = (new->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) && new->prepath;
- if (server->origin_fullpath && - dfs_src_pathname_equal(server->origin_fullpath, ctx->source)) + if (tcon->origin_fullpath && + dfs_src_pathname_equal(tcon->origin_fullpath, ctx->source)) return 1;
if (old_set && new_set && !strcmp(new->prepath, old->prepath)) @@ -2782,10 +2792,10 @@ cifs_match_super(struct super_block *sb, void *data) spin_lock(&ses->ses_lock); spin_lock(&ses->chan_lock); spin_lock(&tcon->tc_lock); - if (!match_server(tcp_srv, ctx) || + if (!match_server(tcp_srv, ctx, true) || !match_session(ses, ctx) || !match_tcon(tcon, ctx) || - !match_prepath(sb, tcp_srv, mnt_data)) { + !match_prepath(sb, tcon, mnt_data)) { rc = 0; goto out; } diff --git a/fs/smb/client/dfs.c b/fs/smb/client/dfs.c index 2390b2fedd6a3..267536a7531df 100644 --- a/fs/smb/client/dfs.c +++ b/fs/smb/client/dfs.c @@ -249,14 +249,12 @@ static int __dfs_mount_share(struct cifs_mount_ctx *mnt_ctx) server = mnt_ctx->server; tcon = mnt_ctx->tcon;
- mutex_lock(&server->refpath_lock); - spin_lock(&server->srv_lock); - if (!server->origin_fullpath) { - server->origin_fullpath = origin_fullpath; + spin_lock(&tcon->tc_lock); + if (!tcon->origin_fullpath) { + tcon->origin_fullpath = origin_fullpath; origin_fullpath = NULL; } - spin_unlock(&server->srv_lock); - mutex_unlock(&server->refpath_lock); + spin_unlock(&tcon->tc_lock);
if (list_empty(&tcon->dfs_ses_list)) { list_replace_init(&mnt_ctx->dfs_ses_list, @@ -279,18 +277,13 @@ int dfs_mount_share(struct cifs_mount_ctx *mnt_ctx, bool *isdfs) { struct smb3_fs_context *ctx = mnt_ctx->fs_ctx; struct cifs_ses *ses; - char *source = ctx->source; bool nodfs = ctx->nodfs; int rc;
*isdfs = false; - /* Temporarily set @ctx->source to NULL as we're not matching DFS - * superblocks yet. See cifs_match_super() and match_server(). - */ - ctx->source = NULL; rc = get_session(mnt_ctx, NULL); if (rc) - goto out; + return rc;
ctx->dfs_root_ses = mnt_ctx->ses; /* @@ -304,7 +297,7 @@ int dfs_mount_share(struct cifs_mount_ctx *mnt_ctx, bool *isdfs) rc = dfs_get_referral(mnt_ctx, ctx->UNC + 1, NULL, NULL); if (rc) { if (rc != -ENOENT && rc != -EOPNOTSUPP && rc != -EIO) - goto out; + return rc; nodfs = true; } } @@ -312,7 +305,7 @@ int dfs_mount_share(struct cifs_mount_ctx *mnt_ctx, bool *isdfs) rc = cifs_mount_get_tcon(mnt_ctx); if (!rc) rc = cifs_is_path_remote(mnt_ctx); - goto out; + return rc; }
*isdfs = true; @@ -328,12 +321,7 @@ int dfs_mount_share(struct cifs_mount_ctx *mnt_ctx, bool *isdfs) rc = __dfs_mount_share(mnt_ctx); if (ses == ctx->dfs_root_ses) cifs_put_smb_ses(ses); -out: - /* - * Restore previous value of @ctx->source so DFS superblock can be - * matched in cifs_match_super(). - */ - ctx->source = source; + return rc; }
@@ -567,11 +555,11 @@ int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const stru 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 cifs_sb_info *cifs_sb = NULL; + struct super_block *sb = NULL; struct dfs_info3_param ref = {0}; + char *tree;
/* only send once per connect */ spin_lock(&tcon->tc_lock); @@ -603,19 +591,18 @@ int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const stru 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); + sb = cifs_get_dfs_tcon_super(tcon); + if (!IS_ERR(sb)) + cifs_sb = CIFS_SB(sb);
- /* If it is not dfs or there was no cached dfs referral, then reconnect to same share */ - if (!server->leaf_fullpath || + /* + * Tree connect to last share in @tcon->tree_name whether dfs super or + * cached dfs referral was not found. + */ + if (!cifs_sb || !server->leaf_fullpath || dfs_cache_noreq_find(server->leaf_fullpath + 1, &ref, &tl)) { - rc = ops->tree_connect(xid, tcon->ses, tcon->tree_name, tcon, cifs_sb->local_nls); + rc = ops->tree_connect(xid, tcon->ses, tcon->tree_name, tcon, + cifs_sb ? cifs_sb->local_nls : nlsc); goto out; }
diff --git a/fs/smb/client/dfs.h b/fs/smb/client/dfs.h index 1c90df5ecfbda..98e9d2aca6a7a 100644 --- a/fs/smb/client/dfs.h +++ b/fs/smb/client/dfs.h @@ -39,16 +39,15 @@ static inline char *dfs_get_automount_devname(struct dentry *dentry, void *page) { struct cifs_sb_info *cifs_sb = CIFS_SB(dentry->d_sb); struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb); - struct TCP_Server_Info *server = tcon->ses->server; size_t len; char *s;
- spin_lock(&server->srv_lock); - if (unlikely(!server->origin_fullpath)) { - spin_unlock(&server->srv_lock); + spin_lock(&tcon->tc_lock); + if (unlikely(!tcon->origin_fullpath)) { + spin_unlock(&tcon->tc_lock); return ERR_PTR(-EREMOTE); } - spin_unlock(&server->srv_lock); + spin_unlock(&tcon->tc_lock);
s = dentry_path_raw(dentry, page, PATH_MAX); if (IS_ERR(s)) @@ -57,16 +56,16 @@ static inline char *dfs_get_automount_devname(struct dentry *dentry, void *page) if (!s[1]) s++;
- spin_lock(&server->srv_lock); - len = strlen(server->origin_fullpath); + spin_lock(&tcon->tc_lock); + len = strlen(tcon->origin_fullpath); if (s < (char *)page + len) { - spin_unlock(&server->srv_lock); + spin_unlock(&tcon->tc_lock); return ERR_PTR(-ENAMETOOLONG); }
s -= len; - memcpy(s, server->origin_fullpath, len); - spin_unlock(&server->srv_lock); + memcpy(s, tcon->origin_fullpath, len); + spin_unlock(&tcon->tc_lock); convert_delimiter(s, '/');
return s; diff --git a/fs/smb/client/dfs_cache.c b/fs/smb/client/dfs_cache.c index 1513b2709889b..33adf43a01f1d 100644 --- a/fs/smb/client/dfs_cache.c +++ b/fs/smb/client/dfs_cache.c @@ -1248,18 +1248,20 @@ static int refresh_tcon(struct cifs_tcon *tcon, bool force_refresh) int dfs_cache_remount_fs(struct cifs_sb_info *cifs_sb) { struct cifs_tcon *tcon; - struct TCP_Server_Info *server;
if (!cifs_sb || !cifs_sb->master_tlink) return -EINVAL;
tcon = cifs_sb_master_tcon(cifs_sb); - server = tcon->ses->server;
- if (!server->origin_fullpath) { + spin_lock(&tcon->tc_lock); + if (!tcon->origin_fullpath) { + spin_unlock(&tcon->tc_lock); cifs_dbg(FYI, "%s: not a dfs mount\n", __func__); return 0; } + spin_unlock(&tcon->tc_lock); + /* * 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). diff --git a/fs/smb/client/misc.c b/fs/smb/client/misc.c index cd914be905b24..b0dedc26643b6 100644 --- a/fs/smb/client/misc.c +++ b/fs/smb/client/misc.c @@ -156,6 +156,7 @@ tconInfoFree(struct cifs_tcon *tcon) #ifdef CONFIG_CIFS_DFS_UPCALL dfs_put_root_smb_sessions(&tcon->dfs_ses_list); #endif + kfree(tcon->origin_fullpath); kfree(tcon); }
@@ -1106,20 +1107,25 @@ struct super_cb_data { struct super_block *sb; };
-static void tcp_super_cb(struct super_block *sb, void *arg) +static void tcon_super_cb(struct super_block *sb, void *arg) { struct super_cb_data *sd = arg; - struct TCP_Server_Info *server = sd->data; struct cifs_sb_info *cifs_sb; - struct cifs_tcon *tcon; + struct cifs_tcon *t1 = sd->data, *t2;
if (sd->sb) return;
cifs_sb = CIFS_SB(sb); - tcon = cifs_sb_master_tcon(cifs_sb); - if (tcon->ses->server == server) + t2 = cifs_sb_master_tcon(cifs_sb); + + spin_lock(&t2->tc_lock); + if (t1->ses == t2->ses && + t1->ses->server == t2->ses->server && + t2->origin_fullpath && + dfs_src_pathname_equal(t2->origin_fullpath, t1->origin_fullpath)) sd->sb = sb; + spin_unlock(&t2->tc_lock); }
static struct super_block *__cifs_get_super(void (*f)(struct super_block *, void *), @@ -1145,6 +1151,7 @@ static struct super_block *__cifs_get_super(void (*f)(struct super_block *, void return sd.sb; } } + pr_warn_once("%s: could not find dfs superblock\n", __func__); return ERR_PTR(-EINVAL); }
@@ -1154,9 +1161,15 @@ static void __cifs_put_super(struct super_block *sb) cifs_sb_deactive(sb); }
-struct super_block *cifs_get_tcp_super(struct TCP_Server_Info *server) +struct super_block *cifs_get_dfs_tcon_super(struct cifs_tcon *tcon) { - return __cifs_get_super(tcp_super_cb, server); + spin_lock(&tcon->tc_lock); + if (!tcon->origin_fullpath) { + spin_unlock(&tcon->tc_lock); + return ERR_PTR(-ENOENT); + } + spin_unlock(&tcon->tc_lock); + return __cifs_get_super(tcon_super_cb, tcon); }
void cifs_put_tcp_super(struct super_block *sb) @@ -1238,9 +1251,16 @@ int cifs_inval_name_dfs_link_error(const unsigned int xid, */ if (strlen(full_path) < 2 || !cifs_sb || (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) || - !is_tcon_dfs(tcon) || !ses->server->origin_fullpath) + !is_tcon_dfs(tcon)) return 0;
+ spin_lock(&tcon->tc_lock); + if (!tcon->origin_fullpath) { + spin_unlock(&tcon->tc_lock); + return 0; + } + spin_unlock(&tcon->tc_lock); + /* * Slow path - tcon is DFS and @full_path has prefix path, so attempt * to get a referral to figure out whether it is an DFS link. @@ -1264,7 +1284,7 @@ int cifs_inval_name_dfs_link_error(const unsigned int xid,
/* * XXX: we are not using dfs_cache_find() here because we might - * end filling all the DFS cache and thus potentially + * end up filling all the DFS cache and thus potentially * removing cached DFS targets that the client would eventually * need during failover. */