вс, 10 мар. 2019 г. в 23:01, Ronnie Sahlberg <lsahlber@xxxxxxxxxx>:
>
> 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 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 ofthen need 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@xxxxxxxxxx>
> ---
> fs/cifs/cifsglob.h | 3 ++
> fs/cifs/smb2inode.c | 15 ++++---
> fs/cifs/smb2ops.c | 111 +++++++++++++++++++++++++++++++++++++++++++---------
> fs/cifs/smb2pdu.c | 12 +++---
> fs/cifs/smb2proto.h | 3 ++
> 5 files changed, 116 insertions(+), 28 deletions(-)
>
> diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
> index f293e052e351..b8360ca221eb 100644
> --- 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;
The structure contains Name[1] - length of 1 byte...
> };
>
> /*
> diff --git a/fs/cifs/smb2inode.c b/fs/cifs/smb2inode.c
> index 01a76bccdb8d..b6e07e2eed10 100644
> --- 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 085e91436da7..0d8bf87592ff 100644
> --- 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 +667,87 @@ 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);
...but OutputLenght is sizeof(struct smb2_file_all_info) + PATH_MAX * 2.
> + 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;
> + rc = smb2_validate_and_copy_iov(
> + le16_to_cpu(qi_rsp->OutputBufferOffset),
> + le32_to_cpu(qi_rsp->OutputBufferLength),
> + &rsp_iov[1], sizeof(struct smb2_file_all_info),
> + (char *)&tcon->crfid.file_all_info);
so, the above call will cause buffer overflow. Please include PATH_MAX
* 2 bytes into the structure to hold the name or even make a pointer
for the 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 60fbe306f604..cfe9fe41ccf5 100644
> --- 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 87733b27a65f..72cc563c32fe 100644
> --- 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);
> --
> 2.13.6
>
In general we should probably need to set oplock/lease level on the
inode of the root, so the existing caching mechanism (see
cifs_inode_need_reval in inode.c) can handle stat calls, so they don't
reach to query_path_info(). But it seems to be out of scope of this
patch and might be done separately.
--
Best regards,
Pavel Shilovsky
