yaffs : Change the way yaffs direct handles permissions for open etc.

The previous code was convoluted and hid some obscure problems.

This refactoring is a lot easier to understand and maintain.

Signed-off-by: Charles Manning <cdhmanning@gmail.com>

diff --git a/direct/yaffsfs.c b/direct/yaffsfs.c
index f95c19906ac7f6cde771177700eacab25e7d01e9..0b236ff86669f0545e38ef0df85bb807c2b1a5f5 100644 (file)
--- a/direct/yaffsfs.c
+++ b/direct/yaffsfs.c
@@ -571,6 +571,8 @@ int yaffs_dup(int fd)
 
 }
 
+
+
 int yaffs_open_sharing(const YCHAR *path, int oflag, int mode, int sharing)
 {
        yaffs_obj_t *obj = NULL;
@@ -581,6 +583,7 @@ int yaffs_open_sharing(const YCHAR *path, int oflag, int mode, int sharing)
        int openDenied = 0;
        int symDepth = 0;
        int errorReported = 0;
+       int rwflags = oflag & ( O_RDWR | O_RDONLY | O_WRONLY);
        __u8 shareRead = (sharing & YAFFS_SHARE_READ) ?  1 : 0;
        __u8 shareWrite = (sharing & YAFFS_SHARE_WRITE) ? 1 : 0;
        __u8 sharedReadAllowed;
@@ -600,6 +603,10 @@ int yaffs_open_sharing(const YCHAR *path, int oflag, int mode, int sharing)
 
        /* Todo: Are there any more flag combos to sanitise ? */
 
+       /* Figure out if reading or writing is requested */
+
+       readRequested = (rwflags == O_RDWR || rwflags == O_RDONLY) ? 1 : 0;
+       writeRequested = (rwflags == O_RDWR || rwflags == O_WRONLY) ? 1 : 0;
 
        yaffsfs_Lock();
 
@@ -640,16 +647,10 @@ int yaffs_open_sharing(const YCHAR *path, int oflag, int mode, int sharing)
                        }
 
                        /* Check file permissions */
-                       if( (oflag & (O_RDWR | O_WRONLY)) == 0 &&     /* ie O_RDONLY */
-                          !(obj->yst_mode & S_IREAD))
-                               openDenied = 1;
-
-                       if( (oflag & O_RDWR) &&
-                          !(obj->yst_mode & S_IREAD))
+                       if( readRequested && !(obj->yst_mode & S_IREAD))
                                openDenied = 1;
 
-                       if( (oflag & (O_RDWR | O_WRONLY)) &&
-                          !(obj->yst_mode & S_IWRITE))
+                       if( writeRequested && !(obj->yst_mode & S_IWRITE))
                                openDenied = 1;
 
                        /* Check sharing of an existing object. */
@@ -672,12 +673,11 @@ int yaffs_open_sharing(const YCHAR *path, int oflag, int mode, int sharing)
                                                if(hx->reading)
                                                        alreadyReading = 1;
                                                if(hx->writing)
-                                                       alreadyWriting = 0;
+                                                       alreadyWriting = 1;
                                        }
                                }
 
-                               readRequested = (oflag & (O_RDWR | O_RDONLY)) ? 1 : 0;
-                               writeRequested = (oflag & (O_RDWR | O_WRONLY)) ? 1 : 0;
+
 
                                if((!sharedReadAllowed && readRequested)|| 
                                        (!shareRead  && alreadyReading) ||
@@ -714,8 +714,8 @@ int yaffs_open_sharing(const YCHAR *path, int oflag, int mode, int sharing)
                        }
                        
                        yh->inodeId = inodeId;
-                       yh->reading = (oflag & (O_RDONLY | O_RDWR)) ? 1 : 0;
-                       yh->writing = (oflag & (O_WRONLY | O_RDWR)) ? 1 : 0;
+                       yh->reading = readRequested;
+                       yh->writing = writeRequested;
                        yh->append =  (oflag & O_APPEND) ? 1 : 0;
                        yh->position = 0;
                        yh->shareRead = shareRead;
@@ -831,7 +831,11 @@ int yaffsfs_do_read(int fd, void *vbuf, unsigned int nbyte, int isPread, int off
                /* bad handle */
                yaffsfs_SetError(-EBADF);
                totalRead = -1;
-       } else if( h && obj){
+       } else if(!h->reading){
+               /* Not a reading handle */
+               yaffsfs_SetError(-EINVAL);
+               totalRead = -1;
+       } else {
                if(isPread)
                        startPos = offset;
                else
@@ -926,7 +930,7 @@ int yaffsfs_do_write(int fd, const void *vbuf, unsigned int nbyte, int isPwrite,
        } else if( h && obj && (!h->writing || obj->my_dev->read_only)){
                yaffsfs_SetError(-EINVAL);
                totalWritten=-1;
-       } else if( h && obj){
+       } else {
                if(h->append)
                        startPos = yaffs_get_obj_length(obj);
                else if(isPwrite)