[patch 2/2] uml: fix major & minor handling in hostfs

From: blaisorblade_spam
Date: Thu Oct 07 2004 - 16:04:56 EST



Currently hostfs passes the rdev value from stat() on the host as rdev value
to return to stat() on the guest; but we cannot pass rdev as is because glibc
and the kernel disagree about its definition. So we must decode it in a
major/minor couple with glibc macros and re-encode it in kernelspace code.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade_spam@xxxxxxxx>
---

linux-2.6.9-current-paolo/fs/hostfs/hostfs.h | 2 +-
linux-2.6.9-current-paolo/fs/hostfs/hostfs_kern.c | 11 ++++++++---
linux-2.6.9-current-paolo/fs/hostfs/hostfs_user.c | 10 +++++++---
3 files changed, 16 insertions(+), 7 deletions(-)

diff -puN fs/hostfs/hostfs.h~uml-hostfs-fix-maj-min fs/hostfs/hostfs.h
--- linux-2.6.9-current/fs/hostfs/hostfs.h~uml-hostfs-fix-maj-min 2004-10-07 17:38:01.759274464 +0200
+++ linux-2.6.9-current-paolo/fs/hostfs/hostfs.h 2004-10-07 17:38:01.763273856 +0200
@@ -38,7 +38,7 @@ extern int stat_file(const char *path, u
int *blksize_out, unsigned long long *blocks_out);
extern int access_file(char *path, int r, int w, int x);
extern int open_file(char *path, int r, int w, int append);
-extern int file_type(const char *path, int *rdev);
+extern int file_type(const char *path, int *maj, int *min);
extern void *open_dir(char *path, int *err_out);
extern char *read_dir(void *stream, unsigned long long *pos,
unsigned long long *ino_out, int *len_out);
diff -puN fs/hostfs/hostfs_kern.c~uml-hostfs-fix-maj-min fs/hostfs/hostfs_kern.c
--- linux-2.6.9-current/fs/hostfs/hostfs_kern.c~uml-hostfs-fix-maj-min 2004-10-07 17:38:01.760274312 +0200
+++ linux-2.6.9-current-paolo/fs/hostfs/hostfs_kern.c 2004-10-07 17:38:01.764273704 +0200
@@ -18,6 +18,7 @@
#include <linux/buffer_head.h>
#include <linux/root_dev.h>
#include <linux/statfs.h>
+#include <linux/kdev_t.h>
#include <asm/uaccess.h>
#include "hostfs.h"
#include "kern_util.h"
@@ -230,7 +231,7 @@ static int read_inode(struct inode *ino)
if(name == NULL)
goto out;

- if(file_type(name, NULL) == OS_TYPE_SYMLINK){
+ if(file_type(name, NULL, NULL) == OS_TYPE_SYMLINK){
name = follow_link(name);
if(IS_ERR(name)){
err = PTR_ERR(name);
@@ -523,13 +524,17 @@ static struct address_space_operations h
static int init_inode(struct inode *inode, struct dentry *dentry)
{
char *name;
- int type, err = -ENOMEM, rdev;
+ int type, err = -ENOMEM;
+ int maj, min;
+ dev_t rdev = 0;

if(dentry){
name = dentry_name(dentry, 0);
if(name == NULL)
goto out;
- type = file_type(name, &rdev);
+ type = file_type(name, &maj, &min);
+ /*Reencode maj and min with the kernel encoding.*/
+ rdev = MKDEV(maj, min);
kfree(name);
}
else type = OS_TYPE_DIR;
diff -puN fs/hostfs/hostfs_user.c~uml-hostfs-fix-maj-min fs/hostfs/hostfs_user.c
--- linux-2.6.9-current/fs/hostfs/hostfs_user.c~uml-hostfs-fix-maj-min 2004-10-07 17:38:01.761274160 +0200
+++ linux-2.6.9-current-paolo/fs/hostfs/hostfs_user.c 2004-10-07 17:38:01.764273704 +0200
@@ -54,14 +54,18 @@ int stat_file(const char *path, unsigned
return(0);
}

-int file_type(const char *path, int *rdev)
+int file_type(const char *path, int *maj, int *min)
{
struct stat64 buf;

if(lstat64(path, &buf) < 0)
return(-errno);
- if(rdev != NULL)
- *rdev = buf.st_rdev;
+ /*We cannot pass rdev as is because glibc and the kernel disagree
+ *about its definition.*/
+ if(maj != NULL)
+ *maj = major(buf.st_rdev);
+ if(min != NULL)
+ *min = minor(buf.st_rdev);

if(S_ISDIR(buf.st_mode)) return(OS_TYPE_DIR);
else if(S_ISLNK(buf.st_mode)) return(OS_TYPE_SYMLINK);
_
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/