Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 25c7f41e authored by Pavel Shilovsky's avatar Pavel Shilovsky Committed by Steve French
Browse files

CIFS: Migrate to shared superblock model 



Add cifs_match_super to use in sget to share superblock between mounts
that have the same //server/sharename, credentials and mount options.
It helps us to improve performance on work with future SMB2.1 leases.

Reviewed-by: default avatarJeff Layton <jlayton@redhat.com>
Signed-off-by: default avatarPavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: default avatarSteve French <sfrench@us.ibm.com>
parent f87d39d9

fs/cifs/cifsfs.c

+18 −1
Original line number Diff line number Diff line
@@ -630,6 +630,7 @@ cifs_do_mount(struct file_system_type *fs_type, 
	struct super_block *sb;

	struct cifs_sb_info *cifs_sb;

	struct smb_vol *volume_info;

	struct cifs_mnt_data mnt_data;

	struct dentry *root;



	cFYI(1, "Devname: %s flags: %d ", dev_name, flags);
@@ -646,12 +647,21 @@ cifs_do_mount(struct file_system_type *fs_type, 


	cifs_setup_cifs_sb(volume_info, cifs_sb);



	sb = sget(fs_type, NULL, set_anon_super, NULL);

	mnt_data.vol = volume_info;

	mnt_data.cifs_sb = cifs_sb;

	mnt_data.flags = flags;



	sb = sget(fs_type, cifs_match_super, set_anon_super, &mnt_data);

	if (IS_ERR(sb)) {

		root = ERR_CAST(sb);

		goto out_cifs_sb;

	}



	if (sb->s_fs_info) {

		cFYI(1, "Use existing superblock");

		goto out_shared;

	}



	/*

	 * Copy mount params for use in submounts. Better to do

	 * the copy here and deal with the error before cleanup gets
@@ -680,6 +690,13 @@ cifs_do_mount(struct file_system_type *fs_type, 
	root = cifs_get_root(volume_info, sb);

	if (root == NULL)

		goto out_super;



	cFYI(1, "dentry root is: %p", root);

	goto out;



out_shared:

	root = cifs_get_root(volume_info, sb);

	if (root)

		cFYI(1, "dentry root is: %p", root);

	goto out;

fs/cifs/cifsglob.h

+19 −0
Original line number Diff line number Diff line
@@ -210,6 +210,25 @@ struct smb_vol { 
	struct nls_table *local_nls;

};



#define CIFS_MOUNT_MASK (CIFS_MOUNT_NO_PERM | CIFS_MOUNT_SET_UID | \

			 CIFS_MOUNT_SERVER_INUM | CIFS_MOUNT_DIRECT_IO | \

			 CIFS_MOUNT_NO_XATTR | CIFS_MOUNT_MAP_SPECIAL_CHR | \

			 CIFS_MOUNT_UNX_EMUL | CIFS_MOUNT_NO_BRL | \

			 CIFS_MOUNT_CIFS_ACL | CIFS_MOUNT_OVERR_UID | \

			 CIFS_MOUNT_OVERR_GID | CIFS_MOUNT_DYNPERM | \

			 CIFS_MOUNT_NOPOSIXBRL | CIFS_MOUNT_NOSSYNC | \

			 CIFS_MOUNT_FSCACHE | CIFS_MOUNT_MF_SYMLINKS | \

			 CIFS_MOUNT_MULTIUSER | CIFS_MOUNT_STRICT_IO)



#define CIFS_MS_MASK (MS_RDONLY | MS_MANDLOCK | MS_NOEXEC | MS_NOSUID | \

		      MS_NODEV | MS_SYNCHRONOUS)



struct cifs_mnt_data {

	struct cifs_sb_info *cifs_sb;

	struct smb_vol *vol;

	int flags;

};



struct TCP_Server_Info {

	struct list_head tcp_ses_list;

	struct list_head smb_ses_list;

fs/cifs/connect.c

+102 −0
Original line number Diff line number Diff line
@@ -2146,6 +2146,100 @@ cifs_put_tlink(struct tcon_link *tlink) 
	return;

}



static inline struct tcon_link *

cifs_sb_master_tlink(struct cifs_sb_info *cifs_sb);



static int

compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)

{

	struct cifs_sb_info *old = CIFS_SB(sb);

	struct cifs_sb_info *new = mnt_data->cifs_sb;



	if ((sb->s_flags & CIFS_MS_MASK) != (mnt_data->flags & CIFS_MS_MASK))

		return 0;



	if ((old->mnt_cifs_flags & CIFS_MOUNT_MASK) !=

	    (new->mnt_cifs_flags & CIFS_MOUNT_MASK))

		return 0;



	if (old->rsize != new->rsize)

		return 0;



	/*

	 * We want to share sb only if we don't specify wsize or specified wsize

	 * is greater or equal than existing one.

	 */

	if (new->wsize && new->wsize < old->wsize)

		return 0;



	if (old->mnt_uid != new->mnt_uid || old->mnt_gid != new->mnt_gid)

		return 0;



	if (old->mnt_file_mode != new->mnt_file_mode ||

	    old->mnt_dir_mode != new->mnt_dir_mode)

		return 0;



	if (strcmp(old->local_nls->charset, new->local_nls->charset))

		return 0;



	if (old->actimeo != new->actimeo)

		return 0;



	return 1;

}



int

cifs_match_super(struct super_block *sb, void *data)

{

	struct cifs_mnt_data *mnt_data = (struct cifs_mnt_data *)data;

	struct smb_vol *volume_info;

	struct cifs_sb_info *cifs_sb;

	struct TCP_Server_Info *tcp_srv;

	struct cifsSesInfo *ses;

	struct cifsTconInfo *tcon;

	struct tcon_link *tlink;

	struct sockaddr_storage addr;

	int rc = 0;



	memset(&addr, 0, sizeof(struct sockaddr_storage));



	spin_lock(&cifs_tcp_ses_lock);

	cifs_sb = CIFS_SB(sb);

	tlink = cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));

	if (IS_ERR(tlink)) {

		spin_unlock(&cifs_tcp_ses_lock);

		return rc;

	}

	tcon = tlink_tcon(tlink);

	ses = tcon->ses;

	tcp_srv = ses->server;



	volume_info = mnt_data->vol;



	if (!volume_info->UNCip || !volume_info->UNC)

		goto out;



	rc = cifs_fill_sockaddr((struct sockaddr *)&addr,

				volume_info->UNCip,

				strlen(volume_info->UNCip),

				volume_info->port);

	if (!rc)

		goto out;



	if (!match_server(tcp_srv, (struct sockaddr *)&addr, volume_info) ||

	    !match_session(ses, volume_info) ||

	    !match_tcon(tcon, volume_info->UNC)) {

		rc = 0;

		goto out;

	}



	rc = compare_mount_options(sb, mnt_data);

out:

	cifs_put_tlink(tlink);

	spin_unlock(&cifs_tcp_ses_lock);

	return rc;

}



int

get_dfs_path(int xid, struct cifsSesInfo *pSesInfo, const char *old_path,

	     const struct nls_table *nls_codepage, unsigned int *pnum_referrals,
@@ -2578,6 +2672,14 @@ void cifs_setup_cifs_sb(struct smb_vol *pvolume_info, 
		/* Windows ME may prefer this */

		cFYI(1, "readsize set to minimum: 2048");

	}



	/*

	 * Temporarily set wsize for matching superblock. If we end up using

	 * new sb then cifs_negotiate_wsize will later negotiate it downward

	 * if needed.

	 */

	cifs_sb->wsize = pvolume_info->wsize;



	cifs_sb->mnt_uid = pvolume_info->linux_uid;

	cifs_sb->mnt_gid = pvolume_info->linux_gid;

	cifs_sb->mnt_file_mode = pvolume_info->file_mode;