cifs: cache FILE_ALL_INFO for the shared root handle

When we open the shared root handle also ask for FILE_ALL_INFORMATION since
we can do this at zero cost as part of a compound.
Cache this information as long as the lease is held and return and serve any
future requests from cache.

This allows us to serve "stat /<mountpoint>" directly from cache and avoid
a network roundtrip.  Since clients often want to do this quite a lot
this improve performance slightly.

As an example: xfstest generic/533 performs 43 stat operations on the root
of the share while it is run. Which are eliminated with this patch.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index ddb2994..8b9ecf8 100644 (file)
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -962,11 +962,14 @@ cap_unix(struct cifs_ses *ses)
 
 struct cached_fid {
        bool is_valid:1;        /* Do we have a useable root fid */
+       bool file_all_info_is_valid:1;
+
        struct kref refcount;
        struct cifs_fid *fid;
        struct mutex fid_mutex;
        struct cifs_tcon *tcon;
        struct work_struct lease_break;
+       struct smb2_file_all_info file_all_info;
 };
 
 /*

diff --git a/fs/cifs/smb2inode.c b/fs/cifs/smb2inode.c
index 01a76bc..b6e07e2 100644 (file)
--- a/fs/cifs/smb2inode.c
+++ b/fs/cifs/smb2inode.c
@@ -309,12 +309,17 @@ smb2_query_path_info(const unsigned int xid, struct cifs_tcon *tcon,
                rc = open_shroot(xid, tcon, &fid);
                if (rc)
                        goto out;
-               rc = SMB2_query_info(xid, tcon, fid.persistent_fid,
-                                    fid.volatile_fid, smb2_data);
+
+               if (tcon->crfid.file_all_info_is_valid) {
+                       move_smb2_info_to_cifs(data,
+                                              &tcon->crfid.file_all_info);
+               } else {
+                       rc = SMB2_query_info(xid, tcon, fid.persistent_fid,
+                                            fid.volatile_fid, smb2_data);
+                       if (!rc)
+                               move_smb2_info_to_cifs(data, smb2_data);
+               }
                close_shroot(&tcon->crfid);
-               if (rc)
-                       goto out;
-               move_smb2_info_to_cifs(data, smb2_data);
                goto out;
        }
 

diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 1654d50..a338190 100644 (file)
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -619,6 +619,7 @@ smb2_close_cached_fid(struct kref *ref)
                SMB2_close(0, cfid->tcon, cfid->fid->persistent_fid,
                           cfid->fid->volatile_fid);
                cfid->is_valid = false;
+               cfid->file_all_info_is_valid = false;
        }
 }
 
@@ -643,9 +644,18 @@ smb2_cached_lease_break(struct work_struct *work)
  */
 int open_shroot(unsigned int xid, struct cifs_tcon *tcon, struct cifs_fid *pfid)
 {
-       struct cifs_open_parms oparams;
-       int rc;
-       __le16 srch_path = 0; /* Null - since an open of top of share */
+       struct cifs_ses *ses = tcon->ses;
+       struct TCP_Server_Info *server = ses->server;
+       struct cifs_open_parms oparms;
+       struct smb2_create_rsp *o_rsp = NULL;
+       struct smb2_query_info_rsp *qi_rsp = NULL;
+       int resp_buftype[2];
+       struct smb_rqst rqst[2];
+       struct kvec rsp_iov[2];
+       struct kvec open_iov[SMB2_CREATE_IOV_SIZE];
+       struct kvec qi_iov[1];
+       int rc, flags = 0;
+       __le16 utf16_path = 0; /* Null - since an open of top of share */
        u8 oplock = SMB2_OPLOCK_LEVEL_II;
 
        mutex_lock(&tcon->crfid.fid_mutex);
@@ -657,22 +667,89 @@ int open_shroot(unsigned int xid, struct cifs_tcon *tcon, struct cifs_fid *pfid)
                return 0;
        }
 
-       oparams.tcon = tcon;
-       oparams.create_options = 0;
-       oparams.desired_access = FILE_READ_ATTRIBUTES;
-       oparams.disposition = FILE_OPEN;
-       oparams.fid = pfid;
-       oparams.reconnect = false;
-
-       rc = SMB2_open(xid, &oparams, &srch_path, &oplock, NULL, NULL, NULL);
-       if (rc == 0) {
-               memcpy(tcon->crfid.fid, pfid, sizeof(struct cifs_fid));
-               tcon->crfid.tcon = tcon;
-               tcon->crfid.is_valid = true;
-               kref_init(&tcon->crfid.refcount);
-               kref_get(&tcon->crfid.refcount);
-       }
+       if (smb3_encryption_required(tcon))
+               flags |= CIFS_TRANSFORM_REQ;
+
+       memset(rqst, 0, sizeof(rqst));
+       resp_buftype[0] = resp_buftype[1] = CIFS_NO_BUFFER;
+       memset(rsp_iov, 0, sizeof(rsp_iov));
+
+       /* Open */
+       memset(&open_iov, 0, sizeof(open_iov));
+       rqst[0].rq_iov = open_iov;
+       rqst[0].rq_nvec = SMB2_CREATE_IOV_SIZE;
+
+       oparms.tcon = tcon;
+       oparms.create_options = 0;
+       oparms.desired_access = FILE_READ_ATTRIBUTES;
+       oparms.disposition = FILE_OPEN;
+       oparms.fid = pfid;
+       oparms.reconnect = false;
+
+       rc = SMB2_open_init(tcon, &rqst[0], &oplock, &oparms, &utf16_path);
+       if (rc)
+               goto oshr_exit;
+       smb2_set_next_command(tcon, &rqst[0]);
+
+       memset(&qi_iov, 0, sizeof(qi_iov));
+       rqst[1].rq_iov = qi_iov;
+       rqst[1].rq_nvec = 1;
+
+       rc = SMB2_query_info_init(tcon, &rqst[1], COMPOUND_FID,
+                                 COMPOUND_FID, FILE_ALL_INFORMATION,
+                                 SMB2_O_INFO_FILE, 0,
+                                 sizeof(struct smb2_file_all_info) +
+                                 PATH_MAX * 2, 0, NULL);
+       if (rc)
+               goto oshr_exit;
+
+       smb2_set_related(&rqst[1]);
+
+       rc = compound_send_recv(xid, ses, flags, 2, rqst,
+                               resp_buftype, rsp_iov);
+       if (rc)
+               goto oshr_exit;
+
+       o_rsp = (struct smb2_create_rsp *)rsp_iov[0].iov_base;
+       oparms.fid->persistent_fid = o_rsp->PersistentFileId;
+       oparms.fid->volatile_fid = o_rsp->VolatileFileId;
+#ifdef CONFIG_CIFS_DEBUG2
+       oparms.fid->mid = le64_to_cpu(o_rsp->sync_hdr.MessageId);
+#endif /* CIFS_DEBUG2 */
+
+       if (o_rsp->OplockLevel == SMB2_OPLOCK_LEVEL_LEASE)
+               oplock = smb2_parse_lease_state(server, o_rsp,
+                                               &oparms.fid->epoch,
+                                               oparms.fid->lease_key);
+       else
+               goto oshr_exit;
+
+
+       memcpy(tcon->crfid.fid, pfid, sizeof(struct cifs_fid));
+       tcon->crfid.tcon = tcon;
+       tcon->crfid.is_valid = true;
+       kref_init(&tcon->crfid.refcount);
+       kref_get(&tcon->crfid.refcount);
+
+
+       qi_rsp = (struct smb2_query_info_rsp *)rsp_iov[1].iov_base;
+       if (le32_to_cpu(qi_rsp->OutputBufferLength) < sizeof(struct smb2_file_all_info))
+               goto oshr_exit;
+       rc = smb2_validate_and_copy_iov(
+                               le16_to_cpu(qi_rsp->OutputBufferOffset),
+                               sizeof(struct smb2_file_all_info),
+                               &rsp_iov[1], sizeof(struct smb2_file_all_info),
+                               (char *)&tcon->crfid.file_all_info);
+       if (rc)
+               goto oshr_exit;
+       tcon->crfid.file_all_info_is_valid = 1;
+
+ oshr_exit:
        mutex_unlock(&tcon->crfid.fid_mutex);
+       SMB2_open_free(&rqst[0]);
+       SMB2_query_info_free(&rqst[1]);
+       free_rsp_buf(resp_buftype[0], rsp_iov[0].iov_base);
+       free_rsp_buf(resp_buftype[1], rsp_iov[1].iov_base);
        return rc;
 }
 

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 60fbe30..cfe9fe4 100644 (file)
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -1797,9 +1797,10 @@ create_reconnect_durable_buf(struct cifs_fid *fid)
        return buf;
 }
 
-static __u8
-parse_lease_state(struct TCP_Server_Info *server, struct smb2_create_rsp *rsp,
-                 unsigned int *epoch, char *lease_key)
+__u8
+smb2_parse_lease_state(struct TCP_Server_Info *server,
+                      struct smb2_create_rsp *rsp,
+                      unsigned int *epoch, char *lease_key)
 {
        char *data_offset;
        struct create_context *cc;
@@ -2456,8 +2457,9 @@ SMB2_open(const unsigned int xid, struct cifs_open_parms *oparms, __le16 *path,
        }
 
        if (rsp->OplockLevel == SMB2_OPLOCK_LEVEL_LEASE)
-               *oplock = parse_lease_state(server, rsp, &oparms->fid->epoch,
-                                           oparms->fid->lease_key);
+               *oplock = smb2_parse_lease_state(server, rsp,
+                                                &oparms->fid->epoch,
+                                                oparms->fid->lease_key);
        else
                *oplock = rsp->OplockLevel;
 creat_exit:

diff --git a/fs/cifs/smb2proto.h b/fs/cifs/smb2proto.h
index 87733b2..72cc563 100644 (file)
--- a/fs/cifs/smb2proto.h
+++ b/fs/cifs/smb2proto.h
@@ -223,6 +223,9 @@ extern int smb3_validate_negotiate(const unsigned int, struct cifs_tcon *);
 
 extern enum securityEnum smb2_select_sectype(struct TCP_Server_Info *,
                                        enum securityEnum);
+extern __u8 smb2_parse_lease_state(struct TCP_Server_Info *server,
+                                  struct smb2_create_rsp *rsp,
+                                  unsigned int *epoch, char *lease_key);
 extern int smb3_encryption_required(const struct cifs_tcon *tcon);
 extern int smb2_validate_iov(unsigned int offset, unsigned int buffer_length,
                             struct kvec *iov, unsigned int min_buf_size);