[PATCH AUTOSEL 4.4 08/16] cifs: fallback to older infolevels on findfirst queryinfo retry

[Sasha Levin]

From: Steve French <stfrench@xxxxxxxxxxxxx>

[ Upstream commit 3b7960caceafdfc2cdfe2850487f8d091eb41144 ]

In cases where queryinfo fails, we have cases in cifs (vers=1.0)
where with backupuid mounts we retry the query info with findfirst.
This doesn't work to some NetApp servers which don't support
WindowsXP (and later) infolevel 261 (SMB_FIND_FILE_ID_FULL_DIR_INFO)
so in this case use other info levels (in this case it will usually
be level 257, SMB_FIND_FILE_DIRECTORY_INFO).

(Also fixes some indentation)

See kernel bugzilla 201435

Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 fs/cifs/inode.c | 69 +++++++++++++++++++++++++++----------------------
 1 file changed, 38 insertions(+), 31 deletions(-)

diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 5c3187df9ab9..d8bd8dd36211 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -759,43 +759,50 @@ cifs_get_inode_info(struct inode **inode, const char *full_path,
 	} else if ((rc == -EACCES) && backup_cred(cifs_sb) &&
 		   (strcmp(server->vals->version_string, SMB1_VERSION_STRING)
 		      == 0)) {
-			/*
-			 * For SMB2 and later the backup intent flag is already
-			 * sent if needed on open and there is no path based
-			 * FindFirst operation to use to retry with
-			 */
-
-			srchinf = kzalloc(sizeof(struct cifs_search_info),
-						GFP_KERNEL);
-			if (srchinf == NULL) {
-				rc = -ENOMEM;
-				goto cgii_exit;
-			}
+		/*
+		 * For SMB2 and later the backup intent flag is already
+		 * sent if needed on open and there is no path based
+		 * FindFirst operation to use to retry with
+		 */
+
+		srchinf = kzalloc(sizeof(struct cifs_search_info),
+					GFP_KERNEL);
+		if (srchinf == NULL) {
+			rc = -ENOMEM;
+			goto cgii_exit;
+		}
 
-			srchinf->endOfSearch = false;
+		srchinf->endOfSearch = false;
+		if (tcon->unix_ext)
+			srchinf->info_level = SMB_FIND_FILE_UNIX;
+		else if ((tcon->ses->capabilities &
+			 tcon->ses->server->vals->cap_nt_find) == 0)
+			srchinf->info_level = SMB_FIND_FILE_INFO_STANDARD;
+		else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)
 			srchinf->info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
+		else /* no srvino useful for fallback to some netapp */
+			srchinf->info_level = SMB_FIND_FILE_DIRECTORY_INFO;
 
-			srchflgs = CIFS_SEARCH_CLOSE_ALWAYS |
-					CIFS_SEARCH_CLOSE_AT_END |
-					CIFS_SEARCH_BACKUP_SEARCH;
+		srchflgs = CIFS_SEARCH_CLOSE_ALWAYS |
+				CIFS_SEARCH_CLOSE_AT_END |
+				CIFS_SEARCH_BACKUP_SEARCH;
 
-			rc = CIFSFindFirst(xid, tcon, full_path,
-				cifs_sb, NULL, srchflgs, srchinf, false);
-			if (!rc) {
-				data =
-				(FILE_ALL_INFO *)srchinf->srch_entries_start;
+		rc = CIFSFindFirst(xid, tcon, full_path,
+			cifs_sb, NULL, srchflgs, srchinf, false);
+		if (!rc) {
+			data = (FILE_ALL_INFO *)srchinf->srch_entries_start;
 
-				cifs_dir_info_to_fattr(&fattr,
-				(FILE_DIRECTORY_INFO *)data, cifs_sb);
-				fattr.cf_uniqueid = le64_to_cpu(
-				((SEARCH_ID_FULL_DIR_INFO *)data)->UniqueId);
-				validinum = true;
+			cifs_dir_info_to_fattr(&fattr,
+			(FILE_DIRECTORY_INFO *)data, cifs_sb);
+			fattr.cf_uniqueid = le64_to_cpu(
+			((SEARCH_ID_FULL_DIR_INFO *)data)->UniqueId);
+			validinum = true;
 
-				cifs_buf_release(srchinf->ntwrk_buf_start);
-			}
-			kfree(srchinf);
-			if (rc)
-				goto cgii_exit;
+			cifs_buf_release(srchinf->ntwrk_buf_start);
+		}
+		kfree(srchinf);
+		if (rc)
+			goto cgii_exit;
 	} else
 		goto cgii_exit;
 
-- 
2.19.1