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

From: Sasha Levin
Date: Fri Mar 29 2019 - 21:32:16 EST


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