cifs: add new cifs_iget function and convert unix codepath to use it

cifs: add new cifs_iget function and convert unix codepath to use it

In order to unify some codepaths, introduce a common cifs_fattr struct
for storing inode attributes. The different codepaths (unix, legacy,
normal, etc...) can fill out this struct with inode info. It can then be
passed as an arg to a common set of routines to get and update inodes.

Add a new cifs_iget function that uses iget5_locked to identify inodes.
This will compare inodes based on the uniqueid value in a cifs_fattr
struct.

Rather than filling out an already-created inode, have
cifs_get_inode_info_unix instead fill out cifs_fattr and hand that off
to cifs_iget. cifs_iget can then properly look for hardlinked inodes.

On the readdir side, add a new cifs_readdir_lookup function that spawns
populated dentries. Redefine FILE_UNIX_INFO so that it's basically a
FILE_UNIX_BASIC_INFO that has a few fields wrapped around it. This
allows us to more easily use the same function for filling out the fattr
as the non-readdir codepath.

With this, we should then have proper hardlink detection and can
eventually get rid of some nasty CIFS-specific hacks for handing them.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 25 insertions, 0 deletions

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index e1225e6ded2f..e6435cba8113 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -371,6 +371,7 @@ struct cifsInodeInfo {
         bool oplockPending:1;
         bool delete_pending:1;          /* DELETE_ON_CLOSE is set */
         u64  server_eof;                /* current file size on server */
+        u64  uniqueid;                  /* server inode number */
         struct inode vfs_inode;
 };
 
@@ -472,6 +473,30 @@ struct dfs_info3_param {
         char *node_name;
 };
 
+/*
+ * common struct for holding inode info when searching for or updating an
+ * inode with new info
+ */
+
+#define CIFS_FATTR_DFS_REFERRAL         0x1
+
+struct cifs_fattr {
+        u32             cf_flags;
+        u32             cf_cifsattrs;
+        u64             cf_uniqueid;
+        u64             cf_eof;
+        u64             cf_bytes;
+        uid_t           cf_uid;
+        gid_t           cf_gid;
+        umode_t         cf_mode;
+        dev_t           cf_rdev;
+        unsigned int    cf_nlink;
+        unsigned int    cf_dtype;
+        struct timespec cf_atime;
+        struct timespec cf_mtime;
+        struct timespec cf_ctime;
+};
+
 static inline void free_dfs_info_param(struct dfs_info3_param *param)
 {
         if (param) {