Introduce FIBMAP64.  This is the same as FIBMAP, but takes a u64.

This new routine requires filesystems to implement bmap64 if they want to 
support > 2^31 blocks in a logical file.  We do this to give time for 
filesystems to be properly audited.

Signed-off-by: Mike Waychison <[EMAIL PROTECTED]>

 fs/compat_ioctl.c  |    2 ++
 fs/ioctl.c         |   34 +++++++++++++++++++++++++++++++++-
 include/linux/fs.h |    7 +++++++
 3 files changed, 42 insertions(+), 1 deletion(-)

Index: linux-2.6.23/fs/ioctl.c
===================================================================
--- linux-2.6.23.orig/fs/ioctl.c        2007-10-26 15:28:28.000000000 -0700
+++ linux-2.6.23/fs/ioctl.c     2007-10-26 16:16:28.000000000 -0700
@@ -44,11 +44,24 @@ static int do_fibmap(struct address_spac
                     sector_t *phys_block)
 {
        struct inode *inode = mapping->host;
+       sector_t (*bmap)(struct address_space *, sector_t);
 
        if (!capable(CAP_SYS_RAWIO))
                return -EPERM;
-       if (!mapping->a_ops->bmap)
+
+       if (mapping->a_ops->bmap64) {
+               /* Filesystem has bmap path audited for 64bit. */
+               bmap = mapping->a_ops->bmap64;
+       } else if (mapping->a_ops->bmap) {
+               bmap = mapping->a_ops->bmap;
+               /* Need to verify that the input looks sane when sector_t is
+                * 64bit and the filesystem has only been audited for 32bit. */
+               if ((s32)block < 0)
+                       return -EFBIG;
+       } else {
+               /* no FIBMAP support */
                return -EINVAL;
+       }
 
        lock_kernel();
        /* Avoid races with truncate */
@@ -95,6 +108,25 @@ static int file_ioctl(struct file *filp,
                        res = phys_block;
                        return put_user(res, p);
                }
+               case FIBMAP64:
+               {
+                       struct address_space *mapping = filp->f_mapping;
+                       sector_t phys_block;
+                       u64 block;
+
+                       if ((error = get_user(block, p)) != 0)
+                               return error;
+
+                       /* Make sure that the logical block fits in sector_t */
+                       if ((sector_t)-1 < block)
+                               return -EFBIG;
+
+                       error = do_fibmap(mapping, block, &phys_block);
+                       if (error)
+                               return error;
+
+                       return put_user(block, p);
+               }
                case FIGETBSZ:
                        return put_user(inode->i_sb->s_blocksize, p);
                case FIONREAD:
Index: linux-2.6.23/include/linux/fs.h
===================================================================
--- linux-2.6.23.orig/include/linux/fs.h        2007-10-26 15:25:47.000000000 
-0700
+++ linux-2.6.23/include/linux/fs.h     2007-10-26 15:29:00.000000000 -0700
@@ -220,6 +220,7 @@ extern int dir_notify_enable;
 #define BMAP_IOCTL 1           /* obsolete - kept for compatibility */
 #define FIBMAP    _IO(0x00,1)  /* bmap access */
 #define FIGETBSZ   _IO(0x00,2) /* get the block size used for bmap */
+#define FIBMAP64   _IO(0x00,3) /* bmap access - 64 bit sector numbers */
 
 #define        FS_IOC_GETFLAGS                 _IOR('f', 1, long)
 #define        FS_IOC_SETFLAGS                 _IOW('f', 2, long)
@@ -423,6 +424,12 @@ struct address_space_operations {
        int (*commit_write)(struct file *, struct page *, unsigned, unsigned);
        /* Unfortunately this kludge is needed for FIBMAP. Don't use it */
        sector_t (*bmap)(struct address_space *, sector_t);
+       /*
+        * Version of bmap for filesystems that can safely handle 64bit
+        * sector_t.  Once all filesystems are converted to this, we can drop
+        * bmap().
+        */
+       sector_t (*bmap64)(struct address_space *, sector_t);
        void (*invalidatepage) (struct page *, unsigned long);
        int (*releasepage) (struct page *, gfp_t);
        ssize_t (*direct_IO)(int, struct kiocb *, const struct iovec *iov,
Index: linux-2.6.23/fs/compat_ioctl.c
===================================================================
--- linux-2.6.23.orig/fs/compat_ioctl.c 2007-10-26 15:25:47.000000000 -0700
+++ linux-2.6.23/fs/compat_ioctl.c      2007-10-26 15:29:00.000000000 -0700
@@ -2506,6 +2506,7 @@ COMPATIBLE_IOCTL(FIONREAD)  /* This is a
 /* 0x00 */
 COMPATIBLE_IOCTL(FIBMAP)
 COMPATIBLE_IOCTL(FIGETBSZ)
+COMPATIBLE_IOCTL(FIBMAP64)
 /* 0x03 -- HD/IDE ioctl's used by hdparm and friends.
  *         Some need translations, these do not.
  */
@@ -3597,6 +3598,7 @@ asmlinkage long compat_sys_ioctl(unsigne
 
        case FIBMAP:
        case FIGETBSZ:
+       case FIBMAP64:
        case FIONREAD:
                if (S_ISREG(filp->f_path.dentry->d_inode->i_mode))
                        break;

--
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