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 <mikew@xxxxxxxxxx>
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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