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authorMilan Broz <mbroz@redhat.com>2007-10-19 17:38:36 -0400
committerAlasdair G Kergon <agk@redhat.com>2007-10-19 21:00:58 -0400
commit027d50f92ea26fd065aeb141ebfcbbbe010825e3 (patch)
treee02900d49590ece0e43e21b006c39de08b1178be /include/linux/dm-ioctl.h
parentc7ac86de6a1bcb1b59c83e19b0d0d64a59604ade (diff)
dm io:ctl use constant struct size
Make size of dm_ioctl struct always 312 bytes on all supported architectures. This change retains compatibility with already-compiled code because it uses an embedded offset to locate the payload that follows the structure. On 64-bit architectures there is no change at all; on 32-bit we are increasing the size of dm-ioctl from 308 to 312 bytes. Currently with 32-bit userspace / 64-bit kernel on x86_64 some ioctls (including rename, message) are incorrectly rejected by the comparison against 'param + 1'. This breaks userspace lvrename and multipath 'fail_if_no_path' changes, for example. (BTW Device-mapper uses its own versioning and ignores the ioctl size bits. Only the generic ioctl compat code on mixed arches checks them, and that will continue to accept both sizes for now, but we intend to list 308 as deprecated and eventually remove it.) Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: Guido Guenther <agx@sigxcpu.org> Cc: Kevin Corry <kevcorry@us.ibm.com> Cc: stable@kernel.org
Diffstat (limited to 'include/linux/dm-ioctl.h')
-rw-r--r--include/linux/dm-ioctl.h5
1 files changed, 3 insertions, 2 deletions
diff --git a/include/linux/dm-ioctl.h b/include/linux/dm-ioctl.h
index b93486107821..523281c5b7f5 100644
--- a/include/linux/dm-ioctl.h
+++ b/include/linux/dm-ioctl.h
@@ -131,6 +131,7 @@ struct dm_ioctl {
131 char name[DM_NAME_LEN]; /* device name */ 131 char name[DM_NAME_LEN]; /* device name */
132 char uuid[DM_UUID_LEN]; /* unique identifier for 132 char uuid[DM_UUID_LEN]; /* unique identifier for
133 * the block device */ 133 * the block device */
134 char data[7]; /* padding or data */
134}; 135};
135 136
136/* 137/*
@@ -285,9 +286,9 @@ typedef char ioctl_struct[308];
285#define DM_DEV_SET_GEOMETRY _IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl) 286#define DM_DEV_SET_GEOMETRY _IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl)
286 287
287#define DM_VERSION_MAJOR 4 288#define DM_VERSION_MAJOR 4
288#define DM_VERSION_MINOR 11 289#define DM_VERSION_MINOR 12
289#define DM_VERSION_PATCHLEVEL 0 290#define DM_VERSION_PATCHLEVEL 0
290#define DM_VERSION_EXTRA "-ioctl (2006-10-12)" 291#define DM_VERSION_EXTRA "-ioctl (2007-10-02)"
291 292
292/* Status bits */ 293/* Status bits */
293#define DM_READONLY_FLAG (1 << 0) /* In/Out */ 294#define DM_READONLY_FLAG (1 << 0) /* In/Out */