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cifs: Make use of DFS cache to get new DFS referrals 

This patch will make use of DFS cache routines where appropriate and
do not always request a new referral from server.

Signed-off-by: Paulo Alcantara <palcantara@suse.de>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
This commit is contained in:
Paulo Alcantara 2018-11-14 16:24:03 -02:00 committed by Steve French
parent e8bcdfdbf9
commit 1c780228e9
6 changed files with 116 additions and 87 deletions
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106
fs/cifs/cifs_dfs_ref.c
View File

@ -25,6 +25,7 @@
#include "dns_resolve.h"
#include "cifs_debug.h"
#include "cifs_unicode.h"
#include "dfs_cache.h"
static LIST_HEAD(cifs_dfs_automount_list);
@ -285,16 +286,16 @@ static void dump_referral(const struct dfs_info3_param *ref)
*/
static struct vfsmount *cifs_dfs_do_automount(struct dentry *mntpt)
{
struct dfs_info3_param *referrals = NULL;
unsigned int num_referrals = 0;
struct dfs_info3_param referral = {0};
struct cifs_sb_info *cifs_sb;
struct cifs_ses *ses;
char *full_path;
struct cifs_tcon *tcon;
char *full_path, *root_path;
unsigned int xid;
int i;
int len;
int rc;
struct vfsmount *mnt;
struct tcon_link *tlink;
char sep;
cifs_dbg(FYI, "in %s\n", __func__);
BUG_ON(IS_ROOT(mntpt));
@ -313,53 +314,76 @@ static struct vfsmount *cifs_dfs_do_automount(struct dentry *mntpt)
goto cdda_exit;
}
sep = CIFS_DIR_SEP(cifs_sb);
/* always use tree name prefix */
full_path = build_path_from_dentry_optional_prefix(mntpt, true);
if (full_path == NULL)
goto cdda_exit;
tlink = cifs_sb_tlink(cifs_sb);
if (IS_ERR(tlink)) {
mnt = ERR_CAST(tlink);
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;
}
ses = tlink_tcon(tlink)->ses;
xid = get_xid();
rc = get_dfs_path(xid, ses, full_path + 1, cifs_sb->local_nls,
&num_referrals, &referrals,
cifs_remap(cifs_sb));
free_xid(xid);
cifs_put_tlink(tlink);
mnt = ERR_PTR(-ENOENT);
for (i = 0; i < num_referrals; i++) {
int len;
dump_referral(referrals + i);
/* connect to a node */
len = strlen(referrals[i].node_name);
if (len < 2) {
cifs_dbg(VFS, "%s: Net Address path too short: %s\n",
__func__, referrals[i].node_name);
mnt = ERR_PTR(-EINVAL);
break;
}
mnt = cifs_dfs_do_refmount(mntpt, cifs_sb,
full_path, referrals + i);
cifs_dbg(FYI, "%s: cifs_dfs_do_refmount:%s , mnt:%p\n",
__func__, referrals[i].node_name, mnt);
if (!IS_ERR(mnt))
goto success;
tcon = cifs_sb_master_tcon(cifs_sb);
if (!tcon) {
cifs_dbg(FYI, "%s: master tcon is NULL\n", __func__);
goto free_full_path;
}
/* no valid submounts were found; return error from get_dfs_path() by
* preference */
if (rc != 0)
mnt = ERR_PTR(rc);
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);
success:
free_dfs_info_array(referrals, num_referrals);
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,
&referral, NULL);
}
free_xid(xid);
if (rc) {
mnt = ERR_PTR(rc);
goto free_root_path;
}
dump_referral(&referral);
len = strlen(referral.node_name);
if (len < 2) {
cifs_dbg(VFS, "%s: Net Address path too short: %s\n",
__func__, referral.node_name);
mnt = ERR_PTR(-EINVAL);
goto free_dfs_ref;
}
/*
* cifs_mount() will retry every available node server in case
* of failures.
*/
mnt = cifs_dfs_do_refmount(mntpt, cifs_sb, full_path, &referral);
cifs_dbg(FYI, "%s: cifs_dfs_do_refmount:%s , mnt:%p\n", __func__,
referral.node_name, mnt);
free_dfs_ref:
free_dfs_info_param(&referral);
free_root_path:
kfree(root_path);
free_full_path:
kfree(full_path);
cdda_exit:

17
fs/cifs/cifsfs.c
View File

@ -52,6 +52,9 @@
#include "cifs_spnego.h"
#include "fscache.h"
#include "smb2pdu.h"
#ifdef CONFIG_CIFS_DFS_UPCALL
#include "dfs_cache.h"
#endif
int cifsFYI = 0;
bool traceSMB;
@ -1494,10 +1497,15 @@ init_cifs(void)
if (rc)
goto out_destroy_mids;
#ifdef CONFIG_CIFS_DFS_UPCALL
rc = dfs_cache_init();
if (rc)
goto out_destroy_request_bufs;
#endif /* CONFIG_CIFS_DFS_UPCALL */
#ifdef CONFIG_CIFS_UPCALL
rc = init_cifs_spnego();
if (rc)
goto out_destroy_request_bufs;
goto out_destroy_dfs_cache;
#endif /* CONFIG_CIFS_UPCALL */
#ifdef CONFIG_CIFS_ACL
@ -1525,6 +1533,10 @@ out_register_key_type:
#endif
#ifdef CONFIG_CIFS_UPCALL
exit_cifs_spnego();
out_destroy_dfs_cache:
#endif
#ifdef CONFIG_CIFS_DFS_UPCALL
dfs_cache_destroy();
out_destroy_request_bufs:
#endif
cifs_destroy_request_bufs();
@ -1555,6 +1567,9 @@ exit_cifs(void)
#endif
#ifdef CONFIG_CIFS_UPCALL
exit_cifs_spnego();
#endif
#ifdef CONFIG_CIFS_DFS_UPCALL
dfs_cache_destroy();
#endif
cifs_destroy_request_bufs();
cifs_destroy_mids();

1
fs/cifs/cifsglob.h
View File

@ -1551,7 +1551,6 @@ static inline void free_dfs_info_param(struct dfs_info3_param *param)
if (param) {
kfree(param->path_name);
kfree(param->node_name);
kfree(param);
}
}

19
fs/cifs/cifsproto.h
View File

@ -22,6 +22,9 @@
#define _CIFSPROTO_H
#include <linux/nls.h>
#include "trace.h"
#ifdef CONFIG_CIFS_DFS_UPCALL
#include "dfs_cache.h"
#endif
struct statfs;
struct smb_vol;
@ -294,11 +297,6 @@ extern int CIFSGetDFSRefer(const unsigned int xid, struct cifs_ses *ses,
unsigned int *num_of_nodes,
const struct nls_table *nls_codepage, int remap);
extern int get_dfs_path(const unsigned int xid, struct cifs_ses *ses,
const char *old_path,
const struct nls_table *nls_codepage,
unsigned int *num_referrals,
struct dfs_info3_param **referrals, int remap);
extern int parse_dfs_referrals(struct get_dfs_referral_rsp *rsp, u32 rsp_size,
unsigned int *num_of_nodes,
struct dfs_info3_param **target_nodes,
@ -567,4 +565,15 @@ void cifs_free_hash(struct crypto_shash **shash, struct sdesc **sdesc);
extern void rqst_page_get_length(struct smb_rqst *rqst, unsigned int page,
unsigned int *len, unsigned int *offset);
#ifdef CONFIG_CIFS_DFS_UPCALL
static inline int get_dfs_path(const unsigned int xid, struct cifs_ses *ses,
const char *old_path,
const struct nls_table *nls_codepage,
struct dfs_info3_param *referral, int remap)
{
return dfs_cache_find(xid, ses, nls_codepage, remap, old_path,
referral, NULL);
}
#endif
#endif /* _CIFSPROTO_H */

45
fs/cifs/connect.c
View File

@ -56,6 +56,10 @@
#include "fscache.h"
#include "smb2proto.h"
#include "smbdirect.h"
#include "dns_resolve.h"
#ifdef CONFIG_CIFS_DFS_UPCALL
#include "dfs_cache.h"
#endif
extern mempool_t *cifs_req_poolp;
extern bool disable_legacy_dialects;
@ -3262,25 +3266,6 @@ out:
return rc;
}
int
get_dfs_path(const unsigned int xid, struct cifs_ses *ses, const char *old_path,
const struct nls_table *nls_codepage, unsigned int *num_referrals,
struct dfs_info3_param **referrals, int remap)
{
int rc = 0;
if (!ses->server->ops->get_dfs_refer)
return -ENOSYS;
*num_referrals = 0;
*referrals = NULL;
rc = ses->server->ops->get_dfs_refer(xid, ses, old_path,
referrals, num_referrals,
nls_codepage, remap);
return rc;
}
#ifdef CONFIG_DEBUG_LOCK_ALLOC
static struct lock_class_key cifs_key[2];
static struct lock_class_key cifs_slock_key[2];
@ -3931,8 +3916,9 @@ build_unc_path_to_root(const struct smb_vol *vol,
return full_path;
}
/*
* Perform a dfs referral query for a share and (optionally) prefix
/**
* 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
@ -3947,8 +3933,7 @@ expand_dfs_referral(const unsigned int xid, struct cifs_ses *ses,
int check_prefix)
{
int rc;
unsigned int num_referrals = 0;
struct dfs_info3_param *referrals = NULL;
struct dfs_info3_param referral = {0};
char *full_path = NULL, *ref_path = NULL, *mdata = NULL;
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS)
@ -3961,17 +3946,15 @@ expand_dfs_referral(const unsigned int xid, struct cifs_ses *ses,
/* For DFS paths, skip the first '\' of the UNC */
ref_path = check_prefix ? full_path + 1 : volume_info->UNC + 1;
rc = get_dfs_path(xid, ses, ref_path, cifs_sb->local_nls,
&num_referrals, &referrals, cifs_remap(cifs_sb));
if (!rc && num_referrals > 0) {
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, referrals,
full_path + 1, &referral,
&fake_devname);
free_dfs_info_array(referrals, num_referrals);
free_dfs_info_param(&referral);
if (IS_ERR(mdata)) {
rc = PTR_ERR(mdata);
@ -3979,7 +3962,7 @@ expand_dfs_referral(const unsigned int xid, struct cifs_ses *ses,
} else {
cifs_cleanup_volume_info_contents(volume_info);
rc = cifs_setup_volume_info(volume_info, mdata,
fake_devname, false);
fake_devname, false);
}
kfree(fake_devname);
kfree(cifs_sb->mountdata);

15
fs/cifs/smb1ops.c
View File

@ -929,19 +929,18 @@ cifs_unix_dfs_readlink(const unsigned int xid, struct cifs_tcon *tcon,
{
#ifdef CONFIG_CIFS_DFS_UPCALL
int rc;
unsigned int num_referrals = 0;
struct dfs_info3_param *referrals = NULL;
struct dfs_info3_param referral = {0};
rc = get_dfs_path(xid, tcon->ses, searchName, nls_codepage,
&num_referrals, &referrals, 0);
rc = get_dfs_path(xid, tcon->ses, searchName, nls_codepage, &referral,
0);
if (!rc && num_referrals > 0) {
*symlinkinfo = kstrndup(referrals->node_name,
strlen(referrals->node_name),
if (!rc) {
*symlinkinfo = kstrndup(referral.node_name,
strlen(referral.node_name),
GFP_KERNEL);
free_dfs_info_param(&referral);
if (!*symlinkinfo)
rc = -ENOMEM;
free_dfs_info_array(referrals, num_referrals);
}
return rc;
#else /* No DFS support */