cifs: reorganize get_cifs_acl

Thus spake Christoph:

"But this whole set_cifs_acl function is a real mess anyway and needs
some splitting up."

With this change too, it's possible to call acl_to_uid_mode() with a
NULL inode pointer. That (or something close to it) will eventually be
necessary when cifs_get_inode_info is reorganized.

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

3 files changed, 55 insertions, 51 deletions

diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c
index 57ecdc83c26..7f8e6c46d11 100644
--- a/fs/cifs/cifsacl.c
+++ b/fs/cifs/cifsacl.c
@@ -552,67 +552,66 @@ static int build_sec_desc(struct cifs_ntsd *pntsd, struct cifs_ntsd *pnntsd,
         return rc;
 }
 
-
-/* Retrieve an ACL from the server */
-static struct cifs_ntsd *get_cifs_acl(u32 *pacllen, struct inode *inode,
-                                       const char *path, const __u16 *pfid)
+static struct cifs_ntsd *get_cifs_acl_by_fid(struct cifs_sb_info *cifs_sb,
+                __u16 fid, u32 *pacllen)
 {
-        struct cifsFileInfo *open_file = NULL;
-        bool unlock_file = false;
-        int xid;
-        int rc = -EIO;
-        __u16 fid;
-        struct super_block *sb;
-        struct cifs_sb_info *cifs_sb;
         struct cifs_ntsd *pntsd = NULL;
+        int xid, rc;
 
-        cFYI(1, ("get mode from ACL for %s", path));
+        xid = GetXid();
+        rc = CIFSSMBGetCIFSACL(xid, cifs_sb->tcon, fid, &pntsd, pacllen);
+        FreeXid(xid);
 
-        if (inode == NULL)
-                return NULL;
 
-        xid = GetXid();
-        if (pfid == NULL)
-                open_file = find_readable_file(CIFS_I(inode));
-        else
-                fid = *pfid;
+        cFYI(1, ("GetCIFSACL rc = %d ACL len %d", rc, *pacllen));
+        return pntsd;
+}
 
-        sb = inode->i_sb;
-        if (sb == NULL) {
-                FreeXid(xid);
-                return NULL;
-        }
-        cifs_sb = CIFS_SB(sb);
+static struct cifs_ntsd *get_cifs_acl_by_path(struct cifs_sb_info *cifs_sb,
+                const char *path, u32 *pacllen)
+{
+        struct cifs_ntsd *pntsd = NULL;
+        int oplock = 0;
+        int xid, rc;
+        __u16 fid;
 
-        if (open_file) {
-                unlock_file = true;
-                fid = open_file->netfid;
-        } else if (pfid == NULL) {
-                int oplock = 0;
-                /* open file */
-                rc = CIFSSMBOpen(xid, cifs_sb->tcon, path, FILE_OPEN,
-                                READ_CONTROL, 0, &fid, &oplock, NULL,
-                                cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
-                                        CIFS_MOUNT_MAP_SPECIAL_CHR);
-                if (rc != 0) {
-                        cERROR(1, ("Unable to open file to get ACL"));
-                        FreeXid(xid);
-                        return NULL;
-                }
+        xid = GetXid();
+
+        rc = CIFSSMBOpen(xid, cifs_sb->tcon, path, FILE_OPEN, READ_CONTROL, 0,
+                         &fid, &oplock, NULL, cifs_sb->local_nls,
+                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
+        if (rc) {
+                cERROR(1, ("Unable to open file to get ACL"));
+                goto out;
         }
 
         rc = CIFSSMBGetCIFSACL(xid, cifs_sb->tcon, fid, &pntsd, pacllen);
         cFYI(1, ("GetCIFSACL rc = %d ACL len %d", rc, *pacllen));
-        if (unlock_file == true) /* find_readable_file increments ref count */
-                atomic_dec(&open_file->wrtPending);
-        else if (pfid == NULL) /* if opened above we have to close the handle */
-                CIFSSMBClose(xid, cifs_sb->tcon, fid);
-        /* else handle was passed in by caller */
 
+        CIFSSMBClose(xid, cifs_sb->tcon, fid);
+ out:
         FreeXid(xid);
         return pntsd;
 }
 
+/* Retrieve an ACL from the server */
+static struct cifs_ntsd *get_cifs_acl(struct cifs_sb_info *cifs_sb,
+                                      struct inode *inode, const char *path,
+                                      u32 *pacllen)
+{
+        struct cifs_ntsd *pntsd = NULL;
+        struct cifsFileInfo *open_file = NULL;
+
+        if (inode)
+                open_file = find_readable_file(CIFS_I(inode));
+        if (!open_file)
+                return get_cifs_acl_by_path(cifs_sb, path, pacllen);
+
+        pntsd = get_cifs_acl_by_fid(cifs_sb, open_file->netfid, pacllen);
+        atomic_dec(&open_file->wrtPending);
+        return pntsd;
+}
+
 /* Set an ACL on the server */
 static int set_cifs_acl(struct cifs_ntsd *pnntsd, __u32 acllen,
                                 struct inode *inode, const char *path)
@@ -668,14 +667,19 @@ static int set_cifs_acl(struct cifs_ntsd *pnntsd, __u32 acllen,
 }
 
 /* Translate the CIFS ACL (simlar to NTFS ACL) for a file into mode bits */
-void acl_to_uid_mode(struct inode *inode, const char *path, const __u16 *pfid)
+void acl_to_uid_mode(struct cifs_sb_info *cifs_sb, struct inode *inode,
+                     const char *path, const __u16 *pfid)
 {
         struct cifs_ntsd *pntsd = NULL;
         u32 acllen = 0;
         int rc = 0;
 
         cFYI(DBG2, ("converting ACL to mode for %s", path));
-        pntsd = get_cifs_acl(&acllen, inode, path, pfid);
+
+        if (pfid)
+                pntsd = get_cifs_acl_by_fid(cifs_sb, *pfid, &acllen);
+        else
+                pntsd = get_cifs_acl(cifs_sb, inode, path, &acllen);
 
         /* if we can retrieve the ACL, now parse Access Control Entries, ACEs */
         if (pntsd)
@@ -698,7 +702,7 @@ int mode_to_acl(struct inode *inode, const char *path, __u64 nmode)
         cFYI(DBG2, ("set ACL from mode for %s", path));
 
         /* Get the security descriptor */
-        pntsd = get_cifs_acl(&secdesclen, inode, path, NULL);
+        pntsd = get_cifs_acl(CIFS_SB(inode->i_sb), inode, path, &secdesclen);
 
         /* Add three ACEs for owner, group, everyone getting rid of
            other ACEs as chmod disables ACEs and set the security descriptor */
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index d542cf1f69c..f9452329bcc 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -108,8 +108,8 @@ extern int cifs_get_inode_info(struct inode **pinode,
 extern int cifs_get_inode_info_unix(struct inode **pinode,
                         const unsigned char *search_path,
                         struct super_block *sb, int xid);
-extern void acl_to_uid_mode(struct inode *inode, const char *path,
-                            const __u16 *pfid);
+extern void acl_to_uid_mode(struct cifs_sb_info *cifs_sb, struct inode *inode,
+                            const char *path, const __u16 *pfid);
 extern int mode_to_acl(struct inode *inode, const char *path, __u64);
 
 extern int cifs_mount(struct super_block *, struct cifs_sb_info *, char *,
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 84b7bea7367..fad882b075b 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -626,7 +626,7 @@ int cifs_get_inode_info(struct inode **pinode,
         /* fill in 0777 bits from ACL */
         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) {
                 cFYI(1, ("Getting mode bits from ACL"));
-                acl_to_uid_mode(inode, full_path, pfid);
+                acl_to_uid_mode(cifs_sb, inode, full_path, pfid);
         }
 #endif
         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) {