From: Paulo Alcantara <pc@cjr.nz>
Date: Wed, 3 Nov 2021 13:53:29 -0300
Subject: [PATCH] cifs: support nested dfs links over reconnect
Git-commit: c88f7dcd6d6429197fc2fd87b54a894ffcd48e8e
References: jsc#SLE-20656
Patch-mainline: v5.16-rc1
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>
Acked-by: Paulo Alcantara <palcantara@suse.de>
---
fs/cifs/cifs_dfs_ref.c | 64 --
fs/cifs/cifs_fs_sb.h | 5
fs/cifs/cifsglob.h | 24 +
fs/cifs/cifsproto.h | 5
fs/cifs/connect.c | 1122 ++++++++++++++++++++++++-------------------------
fs/cifs/dfs_cache.c | 44 +
fs/cifs/misc.c | 62 --
fs/cifs/smb2ops.c | 10
fs/cifs/smb2pdu.c | 6
9 files changed, 652 insertions(+), 690 deletions(-)
--- a/fs/cifs/cifs_dfs_ref.c
+++ b/fs/cifs/cifs_dfs_ref.c
@@ -306,11 +306,7 @@ static struct vfsmount *cifs_dfs_do_moun
static struct vfsmount *cifs_dfs_do_automount(struct dentry *mntpt)
{
struct cifs_sb_info *cifs_sb;
- struct cifs_ses *ses;
- struct cifs_tcon *tcon;
- char *full_path, *root_path;
- unsigned int xid;
- int rc;
+ char *full_path;
struct vfsmount *mnt;
cifs_dbg(FYI, "in %s\n", __func__);
@@ -322,8 +318,6 @@ static struct vfsmount *cifs_dfs_do_auto
* 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);
@@ -332,65 +326,17 @@ static struct vfsmount *cifs_dfs_do_auto
/* always use tree name prefix */
full_path = build_path_from_dentry_optional_prefix(mntpt, true);
- if (full_path == NULL)
+ if (full_path == NULL) {
+ mnt = ERR_PTR(-ENOMEM);
goto cdda_exit;
+ }
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:
kfree(full_path);
cdda_exit:
cifs_dbg(FYI, "leaving %s\n" , __func__);
--- a/fs/cifs/cifs_fs_sb.h
+++ b/fs/cifs/cifs_fs_sb.h
@@ -83,11 +83,6 @@ 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;
/*
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -791,6 +791,19 @@ struct TCP_Server_Info {
int nr_targets;
#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
};
@@ -1143,7 +1156,6 @@ 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
};
@@ -2017,4 +2029,14 @@ static inline bool is_tcon_dfs(struct ci
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 */
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -609,7 +609,7 @@ int smb2_parse_query_directory(struct ci
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);
@@ -636,4 +636,7 @@ static inline int cifs_create_options(st
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 */
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -335,6 +335,20 @@ static const match_table_t cifs_smb_vers
{ Smb_version_err, NULL }
};
+struct mount_ctx {
+ struct cifs_sb_info *cifs_sb;
+ struct smb_vol *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);
@@ -569,14 +583,66 @@ static int __cifs_reconnect(struct TCP_S
}
#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 (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.
@@ -586,11 +652,10 @@ static int reconnect_dfs_server(struct T
* 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;
@@ -598,49 +663,17 @@ static int reconnect_dfs_server(struct T
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 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
@@ -655,8 +688,8 @@ static int reconnect_dfs_server(struct T
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);
@@ -670,38 +703,15 @@ static int reconnect_dfs_server(struct T
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) {
+ 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)
@@ -1078,6 +1088,10 @@ static void clean_demultiplex_info(struc
*/
}
+#ifdef CONFIG_CIFS_DFS_UPCALL
+ kfree(server->origin_fullpath);
+ kfree(server->leaf_fullpath);
+#endif
kfree(server);
length = atomic_dec_return(&tcpSesAllocCount);
@@ -2881,6 +2895,9 @@ cifs_get_tcp_session(struct smb_vol *vol
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, &volume_info->srcaddr,
sizeof(tcp_ses->srcaddr));
memcpy(&tcp_ses->dstaddr, &volume_info->dstaddr,
@@ -4339,49 +4356,41 @@ cifs_cleanup_volume_info(struct smb_vol
}
/* 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 smb_vol *vol, 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 smb_vol *vol = 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(vol);
if (IS_ERR(server)) {
rc = PTR_ERR(server);
- return rc;
+ server = NULL;
+ goto out;
}
- *nserver = server;
-
if ((vol->max_credits < 20) || (vol->max_credits > 60000))
server->max_credits = SMB2_MAX_CREDITS_AVAILABLE;
else
@@ -4391,26 +4400,25 @@ static int mount_get_conns(struct smb_vo
ses = cifs_get_smb_ses(server, vol);
if (IS_ERR(ses)) {
rc = PTR_ERR(ses);
+ ses = NULL;
return rc;
}
- *nses = ses;
-
if ((vol->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, vol);
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;
@@ -4421,17 +4429,19 @@ static int mount_get_conns(struct smb_vo
* reset of caps checks mount to see if unix extensions disabled
* for just this mount.
*/
- reset_cifs_unix_caps(*xid, tcon, cifs_sb, vol);
+ reset_cifs_unix_caps(xid, tcon, cifs_sb, vol);
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))
@@ -4456,7 +4466,13 @@ static int mount_get_conns(struct smb_vo
(cifs_sb->rsize > server->ops->negotiate_rsize(tcon, vol)))
cifs_sb->rsize = server->ops->negotiate_rsize(tcon, vol);
- 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,
@@ -4486,18 +4502,17 @@ static int mount_setup_tlink(struct cifs
}
#ifdef CONFIG_CIFS_DFS_UPCALL
-static int mount_get_dfs_conns(struct smb_vol *vol, 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;
- vol->nosharesock = true;
- rc = mount_get_conns(vol, 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;
@@ -4538,192 +4553,38 @@ build_unc_path_to_root(const struct smb_
return full_path;
}
-/**
- * expand_dfs_referral - Perform a dfs referral query and update the cifs_sb
- *
- * If a referral is found, cifs_sb->mountdata will be (re-)allocated
- * to a string containing updated options for the submount. Otherwise it
- * will be left untouched.
+/*
+ * expand_dfs_referral - Update cifs_sb from dfs referral path
*
- * 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 smb_vol *volume_info, struct cifs_sb_info *cifs_sb,
- char *ref_path)
-{
- 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(volume_info, 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->mountdata,
- full_path + 1, &referral,
- &fake_devname);
- free_dfs_info_param(&referral);
-
- if (IS_ERR(mdata)) {
- rc = PTR_ERR(mdata);
- mdata = NULL;
- } else {
- cifs_cleanup_volume_info_contents(volume_info);
- rc = cifs_setup_volume_info(volume_info, mdata,
- fake_devname, false);
- }
- kfree(fake_devname);
- kfree(cifs_sb->mountdata);
- cifs_sb->mountdata = 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 smb_vol *fake_vol, struct smb_vol *vol)
-{
- 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(vol->UNC);
- vol->UNC = new_unc;
-
- if (fake_vol->prepath) {
- kfree(vol->prepath);
- vol->prepath = fake_vol->prepath;
- fake_vol->prepath = NULL;
- }
- memcpy(&vol->dstaddr, &fake_vol->dstaddr, sizeof(vol->dstaddr));
-
- return 0;
-}
-
-static int setup_dfs_tgt_conn(const char *path, const char *full_path,
- const struct dfs_cache_tgt_iterator *tgt_it,
- struct cifs_sb_info *cifs_sb, struct smb_vol *vol, unsigned int *xid,
- struct TCP_Server_Info **server, struct cifs_ses **ses,
- struct cifs_tcon **tcon)
+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 ref = {0};
- char *mdata = NULL, *fake_devname = NULL;
- struct smb_vol fake_vol = {NULL};
-
- cifs_dbg(FYI, "%s: dfs path: %s\n", __func__, path);
-
- rc = dfs_cache_get_tgt_referral(path, tgt_it, &ref);
- if (rc)
- return rc;
-
- mdata = cifs_compose_mount_options(cifs_sb->mountdata, full_path + 1, &ref, &fake_devname);
- free_dfs_info_param(&ref);
+ struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
+ struct smb_vol *vol = mnt_ctx->fs_ctx;
+ char *fake_devname = NULL, *mdata = NULL;
+ mdata = cifs_compose_mount_options(cifs_sb->mountdata, full_path + 1, referral,
+ &fake_devname);
if (IS_ERR(mdata)) {
rc = PTR_ERR(mdata);
mdata = NULL;
} else {
- cifs_dbg(FYI, "%s: fake_devname: %s\n", __func__, fake_devname);
- rc = cifs_setup_volume_info(&fake_vol, mdata, fake_devname,
- false);
- }
- kfree(mdata);
- kfree(fake_devname);
-
- if (!rc) {
- /*
- * We use a 'fake_vol' here because we need pass it down to the
- * mount_{get,put} functions to test connection against new DFS
- * targets.
- */
- mount_put_conns(cifs_sb, *xid, *server, *ses, *tcon);
- rc = mount_get_dfs_conns(&fake_vol, cifs_sb, xid, server, ses, tcon);
- if (!rc || (*server && *ses)) {
- /*
- * We were able to connect to new target server.
- * Update current volume info with new target server.
- */
- rc = update_vol_info(tgt_it, &fake_vol, vol);
- }
- }
- cifs_cleanup_volume_info_contents(&fake_vol);
- return rc;
-}
-
-static int do_dfs_failover(const char *path, const char *full_path, struct cifs_sb_info *cifs_sb,
- struct smb_vol *vol, 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;
-
- 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;
-
- for (;;) {
- /* Get next DFS target server - if any */
- rc = get_next_dfs_tgt(&tgt_list, &tgt_it);
- if (rc)
- break;
- /* Connect to next DFS target */
- rc = setup_dfs_tgt_conn(npath, full_path, tgt_it, cifs_sb, vol, xid, server, ses,
- tcon);
- if (!rc || (*server && *ses))
- break;
- }
- if (!rc) {
/*
- * 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);
+ cifs_cleanup_volume_info_contents(vol);
+ rc = cifs_setup_volume_info(vol, mdata, fake_devname, false);
}
+ kfree(fake_devname);
+ kfree(cifs_sb->mountdata);
+ cifs_sb->mountdata = mdata;
-out:
- kfree(npath);
- dfs_cache_free_tgts(&tgt_list);
return rc;
}
#endif
@@ -4837,12 +4698,14 @@ cifs_are_all_path_components_accessible(
* 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 smb_vol *vol,
- 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 smb_vol *vol = mnt_ctx->fs_ctx;
char *full_path;
if (!server->ops->is_path_accessible)
@@ -4881,279 +4744,288 @@ static int is_path_remote(struct cifs_sb
}
#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 smb_vol *vol,
- 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 smb_vol *ctx = mnt_ctx->fs_ctx;
- path = cifs_build_path_to_root(vol, cifs_sb, tcon, added_treename);
- if (!path)
- return -ENOMEM;
+ *isdfs = true;
- rc = is_path_remote(cifs_sb, vol, xid, server, tcon);
- if (rc == -EREMOTE) {
- struct smb_vol v = {NULL};
- /* if @path contains a tree name, skip it in the prefix path */
- if (added_treename) {
- rc = cifs_parse_devname(path, &v);
- if (rc)
- goto out;
- npath = build_unc_path_to_root(&v, cifs_sb, true);
- cifs_cleanup_volume_info_contents(&v);
- } else {
- v.UNC = vol->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->mountdata;
+
+ rc = dfs_cache_get_tgt_referral(ref_path, tit, &ref);
+ if (rc)
+ goto out;
- kfree(*dfs_path);
- *dfs_path = npath;
- rc = -EREMOTE;
+ 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->mountdata) {
+ 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};
-
- cifs_dbg(FYI, "%s: ref_path=%s\n", __func__, ref_path);
+ char *full_path;
+ struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
+ struct smb_vol *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);
- 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 smb_vol *vol)
+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 = {};
- 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 smb_vol *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(vol, 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), vol->UNC + 1, NULL,
- NULL)) {
- if (rc)
- goto error;
- /* Check if it is fully accessible and then mount it */
- rc = is_path_remote(cifs_sb, vol, 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(vol, 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(vol, 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 smb_vol *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(vol, cifs_sb, !!count);
- if (IS_ERR(full_path)) {
- rc = PTR_ERR(full_path);
- full_path = NULL;
- break;
- }
- /* Chase referral */
- oldmnt = cifs_sb->mountdata;
- rc = expand_dfs_referral(xid, root_ses, vol, 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->mountdata) {
- mount_put_conns(cifs_sb, xid, server, ses, tcon);
- rc = mount_get_dfs_conns(vol, 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, vol, 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;
+}
+
+/* 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;
+}
- /* Get next dfs path and then continue chasing them if -EREMOTE */
- rc = next_dfs_prepath(cifs_sb, vol, xid, server, tcon, &ref_path);
- /* Prevent recursion on broken link referrals */
- if (rc == -EREMOTE && ++count > MAX_NESTED_LINKS)
- rc = -ELOOP;
- } while (rc == -EREMOTE);
+int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb_vol *vol)
+{
+ int rc;
+ struct mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = vol, };
+ struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
+ bool isdfs;
- if (rc || !tcon || !ses)
+ 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 = vol->prepath;
vol->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);
- 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:
- 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 smb_vol *vol)
{
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 = vol, };
- rc = mount_get_conns(vol, cifs_sb, &xid, &server, &ses, &tcon);
+ rc = mount_get_conns(&mnt_ctx);
if (rc)
goto error;
- if (tcon) {
- rc = is_path_remote(cifs_sb, vol, 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
@@ -5353,7 +5225,6 @@ 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);
}
@@ -5677,104 +5548,245 @@ cifs_prune_tlinks(struct work_struct *wo
}
#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)
+{
+ spin_lock(&GlobalMid_Lock);
+ if (tcon->ses->server->tcpStatus != CifsExiting)
+ tcon->ses->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;
}
-
- if (tcon->ipc) {
- scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", share);
- rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc);
+ /* Target is another dfs share */
+ rc = update_server_fullpath(server, cifs_sb, target);
+ dfs_cache_free_tgts(tl);
+
+ 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
--- a/fs/cifs/dfs_cache.c
+++ b/fs/cifs/dfs_cache.c
@@ -1359,9 +1359,9 @@ static void mark_for_reconnect_if_needed
}
/* 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;
@@ -1417,6 +1417,20 @@ out:
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
*
@@ -1430,6 +1444,7 @@ out:
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;
@@ -1438,13 +1453,15 @@ int dfs_cache_remount_fs(struct 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;
}
@@ -1452,7 +1469,7 @@ int dfs_cache_remount_fs(struct 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);
@@ -1493,9 +1510,12 @@ static void refresh_mounts(struct cifs_s
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);
}
@@ -1505,8 +1525,16 @@ static void refresh_mounts(struct cifs_s
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);
}
}
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -150,9 +150,6 @@ tconInfoFree(struct cifs_tcon *buf_to_fr
kfree(buf_to_free->nativeFileSystem);
kzfree(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);
}
@@ -1294,69 +1291,20 @@ out:
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
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -2768,6 +2768,7 @@ smb2_get_dfs_refer(const unsigned int xi
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);
@@ -2819,11 +2820,14 @@ smb2_get_dfs_refer(const unsigned int xi
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;
}
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -172,7 +172,11 @@ smb2_reconnect(__le16 smb2_command, stru
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) {