Merge tag '6.1-rc-smb3-client-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6

Pull more cifs updates from Steve French:

 - fix a regression in guest mounts to old servers

 - improvements to directory leasing (caching directory entries safely
   beyond the root directory)

 - symlink improvement (reducing roundtrips needed to process symlinks)

 - an lseek fix (to problem where some dir entries could be skipped)

 - improved ioctl for returning more detailed information on directory
   change notifications

 - clarify multichannel interface query warning

 - cleanup fix (for better aligning buffers using ALIGN and round_up)

 - a compounding fix

 - fix some uninitialized variable bugs found by Coverity and the kernel
   test robot

* tag '6.1-rc-smb3-client-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6:
  smb3: improve SMB3 change notification support
  cifs: lease key is uninitialized in two additional functions when smb1
  cifs: lease key is uninitialized in smb1 paths
  smb3: must initialize two ACL struct fields to zero
  cifs: fix double-fault crash during ntlmssp
  cifs: fix static checker warning
  cifs: use ALIGN() and round_up() macros
  cifs: find and use the dentry for cached non-root directories also
  cifs: enable caching of directories for which a lease is held
  cifs: prevent copying past input buffer boundaries
  cifs: fix uninitialised var in smb2_compound_op()
  cifs: improve symlink handling for smb2+
  smb3: clarify multichannel warning
  cifs: fix regression in very old smb1 mounts
  cifs: fix skipping to incorrect offset in emit_cached_dirents

1 files changed, 25 insertions, 6 deletions

diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c
index 8e060c00c969..2d75ba5aaa8a 100644
--- a/fs/cifs/readdir.c
+++ b/fs/cifs/readdir.c
@@ -844,17 +844,34 @@ static bool emit_cached_dirents(struct cached_dirents *cde,
 				struct dir_context *ctx)
 {
 	struct cached_dirent *dirent;
-	int rc;
+	bool rc;
 
 	list_for_each_entry(dirent, &cde->entries, entry) {
-		if (ctx->pos >= dirent->pos)
+		/*
+		 * Skip all early entries prior to the current lseek()
+		 * position.
+		 */
+		if (ctx->pos > dirent->pos)
 			continue;
+		/*
+		 * We recorded the current ->pos value for the dirent
+		 * when we stored it in the cache.
+		 * However, this sequence of ->pos values may have holes
+		 * in it, for example dot-dirs returned from the server
+		 * are suppressed.
+		 * Handle this bu forcing ctx->pos to be the same as the
+		 * ->pos of the current dirent we emit from the cache.
+		 * This means that when we emit these entries from the cache
+		 * we now emit them with the same ->pos value as in the
+		 * initial scan.
+		 */
 		ctx->pos = dirent->pos;
 		rc = dir_emit(ctx, dirent->name, dirent->namelen,
 			      dirent->fattr.cf_uniqueid,
 			      dirent->fattr.cf_dtype);
 		if (!rc)
 			return rc;
+		ctx->pos++;
 	}
 	return true;
 }
@@ -994,6 +1011,8 @@ static int cifs_filldir(char *find_entry, struct file *file,
 		cifs_unix_basic_to_fattr(&fattr,
 					 &((FILE_UNIX_INFO *)find_entry)->basic,
 					 cifs_sb);
+		if (S_ISLNK(fattr.cf_mode))
+			fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
 		break;
 	case SMB_FIND_FILE_INFO_STANDARD:
 		cifs_std_info_to_fattr(&fattr,
@@ -1202,10 +1221,10 @@ int cifs_readdir(struct file *file, struct dir_context *ctx)
 				 ctx->pos, tmp_buf);
 			cifs_save_resume_key(current_entry, cifsFile);
 			break;
-		} else
-			current_entry =
-				nxt_dir_entry(current_entry, end_of_smb,
-					cifsFile->srch_inf.info_level);
+		}
+		current_entry =
+			nxt_dir_entry(current_entry, end_of_smb,
+				      cifsFile->srch_inf.info_level);
 	}
 	kfree(tmp_buf);