cifs: add a CIFSSMBQFileInfo function

...to get inode attributes via filehandle instead of by path.

In some places, we need to revalidate an inode on an open filehandle,
but we can't necessarily guarantee that the dentry associated with it
will still be valid. When we have an open filehandle already, it makes
more sense to do a filehandle based operation anyway.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index 88e2bc44ac583860e15391041e4c0659e885094f..bf2bff14c24ff6fbaad594887908825e0a0f33ba 100644 (file)
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -142,6 +142,8 @@ extern int CIFSFindNext(const int xid, struct cifsTconInfo *tcon,
 extern int CIFSFindClose(const int, struct cifsTconInfo *tcon,
                        const __u16 search_handle);
 
+extern int CIFSSMBQFileInfo(const int xid, struct cifsTconInfo *tcon,
+                       u16 netfid, FILE_ALL_INFO *pFindData);
 extern int CIFSSMBQPathInfo(const int xid, struct cifsTconInfo *tcon,
                        const unsigned char *searchName,
                        FILE_ALL_INFO *findData,

diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 9d17df3e076860924d072605e13f4a97cbb438cf..4ed97825db3d09bcd18361f65a835a53ccdabbac 100644 (file)
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -3230,8 +3230,72 @@ QInfRetry:
        return rc;
 }
 
+int
+CIFSSMBQFileInfo(const int xid, struct cifsTconInfo *tcon,
+                u16 netfid, FILE_ALL_INFO *pFindData)
+{
+       struct smb_t2_qfi_req *pSMB = NULL;
+       struct smb_t2_qfi_rsp *pSMBr = NULL;
+       int rc = 0;
+       int bytes_returned;
+       __u16 params, byte_count;
+
+QFileInfoRetry:
+       rc = smb_init(SMB_COM_TRANSACTION2, 15, tcon, (void **) &pSMB,
+                     (void **) &pSMBr);
+       if (rc)
+               return rc;
+
+       params = 2 /* level */ + 2 /* fid */;
+       pSMB->t2.TotalDataCount = 0;
+       pSMB->t2.MaxParameterCount = cpu_to_le16(4);
+       /* BB find exact max data count below from sess structure BB */
+       pSMB->t2.MaxDataCount = cpu_to_le16(CIFSMaxBufSize);
+       pSMB->t2.MaxSetupCount = 0;
+       pSMB->t2.Reserved = 0;
+       pSMB->t2.Flags = 0;
+       pSMB->t2.Timeout = 0;
+       pSMB->t2.Reserved2 = 0;
+       pSMB->t2.ParameterOffset = cpu_to_le16(offsetof(struct smb_t2_qfi_req,
+                                              Fid) - 4);
+       pSMB->t2.DataCount = 0;
+       pSMB->t2.DataOffset = 0;
+       pSMB->t2.SetupCount = 1;
+       pSMB->t2.Reserved3 = 0;
+       pSMB->t2.SubCommand = cpu_to_le16(TRANS2_QUERY_FILE_INFORMATION);
+       byte_count = params + 1 /* pad */ ;
+       pSMB->t2.TotalParameterCount = cpu_to_le16(params);
+       pSMB->t2.ParameterCount = pSMB->t2.TotalParameterCount;
+       pSMB->InformationLevel = cpu_to_le16(SMB_QUERY_FILE_ALL_INFO);
+       pSMB->Pad = 0;
+       pSMB->Fid = netfid;
+       pSMB->hdr.smb_buf_length += byte_count;
+
+       rc = SendReceive(xid, tcon->ses, (struct smb_hdr *) pSMB,
+                        (struct smb_hdr *) pSMBr, &bytes_returned, 0);
+       if (rc) {
+               cFYI(1, ("Send error in QPathInfo = %d", rc));
+       } else {                /* decode response */
+               rc = validate_t2((struct smb_t2_rsp *)pSMBr);
 
+               if (rc) /* BB add auto retry on EOPNOTSUPP? */
+                       rc = -EIO;
+               else if (pSMBr->ByteCount < 40)
+                       rc = -EIO;      /* bad smb */
+               else if (pFindData) {
+                       __u16 data_offset = le16_to_cpu(pSMBr->t2.DataOffset);
+                       memcpy((char *) pFindData,
+                              (char *) &pSMBr->hdr.Protocol +
+                              data_offset, sizeof(FILE_ALL_INFO));
+               } else
+                   rc = -ENOMEM;
+       }
+       cifs_buf_release(pSMB);
+       if (rc == -EAGAIN)
+               goto QFileInfoRetry;
 
+       return rc;
+}
 
 int
 CIFSSMBQPathInfo(const int xid, struct cifsTconInfo *tcon,