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: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 4956881..261ca81 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -2146,6 +2146,100 @@
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 @@
/* 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;