xfs: simplify the xfs_getbmap interface
Instead of passing in a formatter callback allocate the bmap buffer
in the caller and process the entries there. Additionally replace
the in-kernel buffer with a new much smaller structure, and unify
the implementation of the different ioctls in a single function.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index aa75389..b01a198 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -1540,17 +1540,26 @@
return error;
}
-STATIC int
-xfs_getbmap_format(void **ap, struct getbmapx *bmv)
+static bool
+xfs_getbmap_format(
+ struct kgetbmap *p,
+ struct getbmapx __user *u,
+ size_t recsize)
{
- struct getbmap __user *base = (struct getbmap __user *)*ap;
-
- /* copy only getbmap portion (not getbmapx) */
- if (copy_to_user(base, bmv, sizeof(struct getbmap)))
- return -EFAULT;
-
- *ap += sizeof(struct getbmap);
- return 0;
+ if (put_user(p->bmv_offset, &u->bmv_offset) ||
+ put_user(p->bmv_block, &u->bmv_block) ||
+ put_user(p->bmv_length, &u->bmv_length) ||
+ put_user(0, &u->bmv_count) ||
+ put_user(0, &u->bmv_entries))
+ return false;
+ if (recsize < sizeof(struct getbmapx))
+ return true;
+ if (put_user(0, &u->bmv_iflags) ||
+ put_user(p->bmv_oflags, &u->bmv_oflags) ||
+ put_user(0, &u->bmv_unused1) ||
+ put_user(0, &u->bmv_unused2))
+ return false;
+ return true;
}
STATIC int
@@ -1560,68 +1569,57 @@
void __user *arg)
{
struct getbmapx bmx = { 0 };
- int error;
+ struct kgetbmap *buf;
+ size_t recsize;
+ int error, i;
- /* struct getbmap is a strict subset of struct getbmapx. */
- if (copy_from_user(&bmx, arg, offsetof(struct getbmapx, bmv_iflags)))
+ switch (cmd) {
+ case XFS_IOC_GETBMAPA:
+ bmx.bmv_iflags = BMV_IF_ATTRFORK;
+ /*FALLTHRU*/
+ case XFS_IOC_GETBMAP:
+ if (file->f_mode & FMODE_NOCMTIME)
+ bmx.bmv_iflags |= BMV_IF_NO_DMAPI_READ;
+ /* struct getbmap is a strict subset of struct getbmapx. */
+ recsize = sizeof(struct getbmap);
+ break;
+ case XFS_IOC_GETBMAPX:
+ recsize = sizeof(struct getbmapx);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (copy_from_user(&bmx, arg, recsize))
return -EFAULT;
if (bmx.bmv_count < 2)
return -EINVAL;
+ if (bmx.bmv_count > ULONG_MAX / recsize)
+ return -ENOMEM;
- bmx.bmv_iflags = (cmd == XFS_IOC_GETBMAPA ? BMV_IF_ATTRFORK : 0);
- if (file->f_mode & FMODE_NOCMTIME)
- bmx.bmv_iflags |= BMV_IF_NO_DMAPI_READ;
+ buf = kmem_zalloc_large(bmx.bmv_count * sizeof(*buf), 0);
+ if (!buf)
+ return -ENOMEM;
- error = xfs_getbmap(XFS_I(file_inode(file)), &bmx, xfs_getbmap_format,
- (__force struct getbmap *)arg+1);
+ error = xfs_getbmap(XFS_I(file_inode(file)), &bmx, buf);
if (error)
- return error;
+ goto out_free_buf;
- /* copy back header - only size of getbmap */
- if (copy_to_user(arg, &bmx, sizeof(struct getbmap)))
- return -EFAULT;
- return 0;
-}
+ error = -EFAULT;
+ if (copy_to_user(arg, &bmx, recsize))
+ goto out_free_buf;
+ arg += recsize;
-STATIC int
-xfs_getbmapx_format(void **ap, struct getbmapx *bmv)
-{
- struct getbmapx __user *base = (struct getbmapx __user *)*ap;
+ for (i = 0; i < bmx.bmv_entries; i++) {
+ if (!xfs_getbmap_format(buf + i, arg, recsize))
+ goto out_free_buf;
+ arg += recsize;
+ }
- if (copy_to_user(base, bmv, sizeof(struct getbmapx)))
- return -EFAULT;
-
- *ap += sizeof(struct getbmapx);
- return 0;
-}
-
-STATIC int
-xfs_ioc_getbmapx(
- struct xfs_inode *ip,
- void __user *arg)
-{
- struct getbmapx bmx;
- int error;
-
- if (copy_from_user(&bmx, arg, sizeof(bmx)))
- return -EFAULT;
-
- if (bmx.bmv_count < 2)
- return -EINVAL;
-
- if (bmx.bmv_iflags & (~BMV_IF_VALID))
- return -EINVAL;
-
- error = xfs_getbmap(ip, &bmx, xfs_getbmapx_format,
- (__force struct getbmapx *)arg+1);
- if (error)
- return error;
-
- /* copy back header */
- if (copy_to_user(arg, &bmx, sizeof(struct getbmapx)))
- return -EFAULT;
-
+ error = 0;
+out_free_buf:
+ kmem_free(buf);
return 0;
}
@@ -1878,10 +1876,8 @@
case XFS_IOC_GETBMAP:
case XFS_IOC_GETBMAPA:
- return xfs_ioc_getbmap(filp, cmd, arg);
-
case XFS_IOC_GETBMAPX:
- return xfs_ioc_getbmapx(ip, arg);
+ return xfs_ioc_getbmap(filp, cmd, arg);
case FS_IOC_GETFSMAP:
return xfs_ioc_getfsmap(ip, arg);