cifs: obtain file access during backup intent lookup (resend)

Rebased and resending the patch.

Path based queries can fail for lack of access, especially during lookup
during open.
open itself would actually succeed becasue of back up intent bit
but queries (either path or file handle based) do not have a means to
specifiy backup intent bit.
So query the file info during lookup using
 trans2 / findfirst / file_id_full_dir_info
to obtain file info as well as file_id/inode value.

Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Acked-by: Jeff Layton <jlayton@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>

1 files changed, 26 insertions, 17 deletions

diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 88bbb3ef95b3..76d0d2998850 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -4214,10 +4214,9 @@ UnixQPathInfoRetry:
 /* xid, tcon, searchName and codepage are input parms, rest are returned */
 int
 CIFSFindFirst(const unsigned int xid, struct cifs_tcon *tcon,
-              const char *searchName,
-              const struct nls_table *nls_codepage,
+              const char *searchName, struct cifs_sb_info *cifs_sb,
               __u16 *pnetfid, __u16 search_flags,
-              struct cifs_search_info *psrch_inf, int remap, const char dirsep)
+              struct cifs_search_info *psrch_inf, bool msearch)
 {
 /* level 257 SMB_ */
         TRANSACTION2_FFIRST_REQ *pSMB = NULL;
@@ -4225,8 +4224,9 @@ CIFSFindFirst(const unsigned int xid, struct cifs_tcon *tcon,
         T2_FFIRST_RSP_PARMS *parms;
         int rc = 0;
         int bytes_returned = 0;
-        int name_len;
+        int name_len, remap;
         __u16 params, byte_count;
+        struct nls_table *nls_codepage;
 
         cFYI(1, "In FindFirst for %s", searchName);
 
@@ -4236,6 +4236,9 @@ findFirstRetry:
         if (rc)
                 return rc;
 
+        nls_codepage = cifs_sb->local_nls;
+        remap = cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR;
+
         if (pSMB->hdr.Flags2 & SMBFLG2_UNICODE) {
                 name_len =
                     cifsConvertToUTF16((__le16 *) pSMB->FileName, searchName,
@@ -4244,24 +4247,29 @@ findFirstRetry:
                 it got remapped to 0xF03A as if it were part of the
                 directory name instead of a wildcard */
                 name_len *= 2;
-                pSMB->FileName[name_len] = dirsep;
-                pSMB->FileName[name_len+1] = 0;
-                pSMB->FileName[name_len+2] = '*';
-                pSMB->FileName[name_len+3] = 0;
-                name_len += 4; /* now the trailing null */
-                pSMB->FileName[name_len] = 0; /* null terminate just in case */
-                pSMB->FileName[name_len+1] = 0;
-                name_len += 2;
+                if (msearch) {
+                        pSMB->FileName[name_len] = CIFS_DIR_SEP(cifs_sb);
+                        pSMB->FileName[name_len+1] = 0;
+                        pSMB->FileName[name_len+2] = '*';
+                        pSMB->FileName[name_len+3] = 0;
+                        name_len += 4; /* now the trailing null */
+                        /* null terminate just in case */
+                        pSMB->FileName[name_len] = 0;
+                        pSMB->FileName[name_len+1] = 0;
+                        name_len += 2;
+                }
         } else {        /* BB add check for overrun of SMB buf BB */
                 name_len = strnlen(searchName, PATH_MAX);
 /* BB fix here and in unicode clause above ie
                 if (name_len > buffersize-header)
                         free buffer exit; BB */
                 strncpy(pSMB->FileName, searchName, name_len);
-                pSMB->FileName[name_len] = dirsep;
-                pSMB->FileName[name_len+1] = '*';
-                pSMB->FileName[name_len+2] = 0;
-                name_len += 3;
+                if (msearch) {
+                        pSMB->FileName[name_len] = CIFS_DIR_SEP(cifs_sb);
+                        pSMB->FileName[name_len+1] = '*';
+                        pSMB->FileName[name_len+2] = 0;
+                        name_len += 3;
+                }
         }
 
         params = 12 + name_len /* includes null */ ;
@@ -4349,7 +4357,8 @@ findFirstRetry:
                         psrch_inf->last_entry = psrch_inf->srch_entries_start +
                                                         lnoff;
 
-                        *pnetfid = parms->SearchHandle;
+                        if (pnetfid)
+                                *pnetfid = parms->SearchHandle;
                 } else {
                         cifs_buf_release(pSMB);
                 }