raw-posix.c: Make GetBSDPath() handle caching options

Add support for caching options that can be specified from the command
line.

The CD-ROM raw char device bypasses the host page cache and therefore
has alignment requirements.  Alignment probing is necessary so only use
the raw char device if BDRV_O_NOCACHE is set.

This patch fixes -cdrom /dev/cdrom on Mac OS X hosts, where bdrv_read()
used to fail due to misaligned requests during image format probing.

Signed-off-by: John Arbuckle <programmingkidx@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

diff --git a/block/raw-posix.c b/block/raw-posix.c
index aec9ec6bbb6baa3ef2d82db1bfbae854cba94efa..d9162fd30647e89dcadb9ac4ea590ef9b4e7fe7d 100644 (file)
--- a/block/raw-posix.c
+++ b/block/raw-posix.c
@@ -1976,8 +1976,8 @@ BlockDriver bdrv_file = {
 
 #if defined(__APPLE__) && defined(__MACH__)
 static kern_return_t FindEjectableCDMedia( io_iterator_t *mediaIterator );
-static kern_return_t GetBSDPath( io_iterator_t mediaIterator, char *bsdPath, CFIndex maxPathSize );
-
+static kern_return_t GetBSDPath(io_iterator_t mediaIterator, char *bsdPath,
+                                CFIndex maxPathSize, int flags);
 kern_return_t FindEjectableCDMedia( io_iterator_t *mediaIterator )
 {
     kern_return_t       kernResult;
@@ -2004,7 +2004,8 @@ kern_return_t FindEjectableCDMedia( io_iterator_t *mediaIterator )
     return kernResult;
 }
 
-kern_return_t GetBSDPath( io_iterator_t mediaIterator, char *bsdPath, CFIndex maxPathSize )
+kern_return_t GetBSDPath(io_iterator_t mediaIterator, char *bsdPath,
+                         CFIndex maxPathSize, int flags)
 {
     io_object_t     nextMedia;
     kern_return_t   kernResult = KERN_FAILURE;
@@ -2017,7 +2018,9 @@ kern_return_t GetBSDPath( io_iterator_t mediaIterator, char *bsdPath, CFIndex ma
         if ( bsdPathAsCFString ) {
             size_t devPathLength;
             strcpy( bsdPath, _PATH_DEV );
-            strcat( bsdPath, "r" );
+            if (flags & BDRV_O_NOCACHE) {
+                strcat(bsdPath, "r");
+            }
             devPathLength = strlen( bsdPath );
             if ( CFStringGetCString( bsdPathAsCFString, bsdPath + devPathLength, maxPathSize - devPathLength, kCFStringEncodingASCII ) ) {
                 kernResult = KERN_SUCCESS;
@@ -2129,8 +2132,8 @@ static int hdev_open(BlockDriverState *bs, QDict *options, int flags,
         int fd;
 
         kernResult = FindEjectableCDMedia( &mediaIterator );
-        kernResult = GetBSDPath( mediaIterator, bsdPath, sizeof( bsdPath ) );
-
+        kernResult = GetBSDPath(mediaIterator, bsdPath, sizeof(bsdPath),
+                                flags);
         if ( bsdPath[ 0 ] != '\0' ) {
             strcat(bsdPath,"s0");
             /* some CDs don't have a partition 0 */