Commit 1c780228 authored by Paulo Alcantara's avatar Paulo Alcantara Committed by Steve French
Browse files

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: default avatarPaulo Alcantara <palcantara@suse.de>
Reviewed-by: default avatarAurelien Aptel <aaptel@suse.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent e8bcdfdb

fs/cifs/cifs_dfs_ref.c

+62 −38
Original line number Diff line number Diff line
@@ -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;



	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();

	rc = get_dfs_path(xid, ses, full_path + 1, cifs_sb->local_nls,

		&num_referrals, &referrals,

		cifs_remap(cifs_sb));



	/*

	 * 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);



	cifs_put_tlink(tlink);

	if (rc) {

		mnt = ERR_PTR(rc);

		goto free_root_path;

	}



	dump_referral(&referral);



	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);

	len = strlen(referral.node_name);

	if (len < 2) {

		cifs_dbg(VFS, "%s: Net Address path too short: %s\n",

				 __func__, referrals[i].node_name);

			 __func__, referral.node_name);

		mnt = ERR_PTR(-EINVAL);

			break;

		goto free_dfs_ref;

	}

		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;

	}



	/* no valid submounts were found; return error from get_dfs_path() by

	 * preference */

	if (rc != 0)

		mnt = ERR_PTR(rc);



success:

	free_dfs_info_array(referrals, num_referrals);

	/*

	 * 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:

fs/cifs/cifsfs.c

+16 −1
Original line number Diff line number Diff line
@@ -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 @@ init_cifs(void) 
#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();

fs/cifs/cifsglob.h

+0 −1
Original line number Diff line number Diff line
@@ -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);

	}

}

fs/cifs/cifsproto.h

+14 −5
Original line number Diff line number Diff line
@@ -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 */

fs/cifs/connect.c

+14 −31
Original line number Diff line number Diff line
@@ -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 @@ cifs_match_super(struct super_block *sb, void *data) 
	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);