[PATCH 06/23] r/o bind mounts: elevate write count for some ioctls

Dave Hansen
2007-07-12T00:31:04Z

Some ioctl()s can cause writes to the filesystem. Take
these, and make them use mnt_want/drop_write() instead.

We need to pass the filp one layer deeper in XFS, but
somebody _just_ pulled it out in February because nobody
was using it, so I don't feel guilty for adding it back.

Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
---

lxc-dave/fs/ext2/ioctl.c | 46 +++++++++-----
lxc-dave/fs/ext3/ioctl.c | 100 +++++++++++++++++++++-----------
lxc-dave/fs/ext4/ioctl.c | 105 +++++++++++++++++++++-------------
lxc-dave/fs/fat/file.c | 10 +--
lxc-dave/fs/hfsplus/ioctl.c | 39 +++++++-----
lxc-dave/fs/jfs/ioctl.c | 33 ++++++----
lxc-dave/fs/ocfs2/ioctl.c | 11 +--
lxc-dave/fs/reiserfs/ioctl.c | 53 +++++++++++------
lxc-dave/fs/xfs/linux-2.6/xfs_ioctl.c | 15 +++-
lxc-dave/fs/xfs/linux-2.6/xfs_iops.c | 7 --
lxc-dave/fs/xfs/linux-2.6/xfs_lrw.c | 9 ++
11 files changed, 272 insertions(+), 156 deletions(-)

diff -puN fs/ext2/ioctl.c~ioctl-mnt-takers fs/ext2/ioctl.c
--- lxc/fs/ext2/ioctl.c~ioctl-mnt-takers 2007-07-10 12:46:05.000000000 -0700
+++ lxc-dave/fs/ext2/ioctl.c 2007-07-10 12:46:05.000000000 -0700
@@ -12,6 +12,7 @@
#include <linux/time.h>
#include <linux/sched.h>
#include <linux/compat.h>
+#include <linux/mount.h>
#include <linux/smp_lock.h>
#include <asm/current.h>
#include <asm/uaccess.h>
@@ -22,6 +23,7 @@ int ext2_ioctl (struct inode * inode, st
{
struct ext2_inode_info *ei = EXT2_I(inode);
unsigned int flags;
+ int ret;

ext2_debug ("cmd = %u, arg = %lu\n", cmd, arg);

@@ -33,14 +35,19 @@ int ext2_ioctl (struct inode * inode, st
case EXT2_IOC_SETFLAGS: {
unsigned int oldflags;

- if (IS_RDONLY(inode))
- return -EROFS;
-
- if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
- return -EACCES;
+ ret = mnt_want_write(filp->f_vfsmnt);
+ if (ret)
+ return ret;
+
+ if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER)) {
+ ret = -EACCES;
+ goto setflags_out;
+ }

- if (get_user(flags, (int __user *) arg))
- return -EFAULT;
+ if (get_user(flags, (int __user *) arg)) {
+ ret = -EFAULT;
+ goto setflags_out;
+ }

if (!S_ISDIR(inode->i_mode))
flags &= ~EXT2_DIRSYNC_FL;
@@ -57,7 +64,8 @@ int ext2_ioctl (struct inode * inode, st
if ((flags ^ oldflags) & (EXT2_APPEND_FL | EXT2_IMMUTABLE_FL)) {
if (!capable(CAP_LINUX_IMMUTABLE)) {
mutex_unlock(&inode->i_mutex);
- return -EPERM;
+ ret = -EPERM;
+ goto setflags_out;
}
}

@@ -69,20 +77,26 @@ int ext2_ioctl (struct inode * inode, st
ext2_set_inode_flags(inode);
inode->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(inode);
- return 0;
+setflags_out:
+ mnt_drop_write(filp->f_vfsmnt);
+ return ret;
}
case EXT2_IOC_GETVERSION:
return put_user(inode->i_generation, (int __user *) arg);
case EXT2_IOC_SETVERSION:
if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
return -EPERM;
- if (IS_RDONLY(inode))
- return -EROFS;
- if (get_user(inode->i_generation, (int __user *) arg))
- return -EFAULT;
- inode->i_ctime = CURRENT_TIME_SEC;
- mark_inode_dirty(inode);
- return 0;
+ ret = mnt_want_write(filp->f_vfsmnt);
+ if (ret)
+ return ret;
+ if (get_user(inode->i_generation, (int __user *) arg)) {
+ ret = -EFAULT;
+ } else {
+ inode->i_ctime = CURRENT_TIME_SEC;
+ mark_inode_dirty(inode);
+ }
+ mnt_drop_write(filp->f_vfsmnt);
+ return ret;
default:
return -ENOTTY;
}
diff -puN fs/ext3/ioctl.c~ioctl-mnt-takers fs/ext3/ioctl.c
--- lxc/fs/ext3/ioctl.c~ioctl-mnt-takers 2007-07-10 12:46:05.000000000 -0700
+++ lxc-dave/fs/ext3/ioctl.c 2007-07-10 12:46:05.000000000 -0700
@@ -12,6 +12,7 @@
#include <linux/capability.h>
#include <linux/ext3_fs.h>
#include <linux/ext3_jbd.h>
+#include <linux/mount.h>
#include <linux/time.h>
#include <linux/compat.h>
#include <linux/smp_lock.h>
@@ -38,14 +39,19 @@ int ext3_ioctl (struct inode * inode, st
unsigned int oldflags;
unsigned int jflag;

- if (IS_RDONLY(inode))
- return -EROFS;
+ err = mnt_want_write(filp->f_vfsmnt);
+ if (err)
+ return err;

- if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
- return -EACCES;
+ if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER)) {
+ err = -EACCES;
+ goto flags_out;
+ }

- if (get_user(flags, (int __user *) arg))
- return -EFAULT;
+ if (get_user(flags, (int __user *) arg)) {
+ err = -EFAULT;
+ goto flags_out;
+ }

if (!S_ISDIR(inode->i_mode))
flags &= ~EXT3_DIRSYNC_FL;
@@ -65,7 +71,8 @@ int ext3_ioctl (struct inode * inode, st
if ((flags ^ oldflags) & (EXT3_APPEND_FL | EXT3_IMMUTABLE_FL)) {
if (!capable(CAP_LINUX_IMMUTABLE)) {
mutex_unlock(&inode->i_mutex);
- return -EPERM;
+ err = -EPERM;
+ goto flags_out;
}
}

@@ -76,7 +83,8 @@ int ext3_ioctl (struct inode * inode, st
if ((jflag ^ oldflags) & (EXT3_JOURNAL_DATA_FL)) {
if (!capable(CAP_SYS_RESOURCE)) {
mutex_unlock(&inode->i_mutex);
- return -EPERM;
+ err = -EPERM;
+ goto flags_out;
}
}

@@ -84,7 +92,8 @@ int ext3_ioctl (struct inode * inode, st
handle = ext3_journal_start(inode, 1);
if (IS_ERR(handle)) {
mutex_unlock(&inode->i_mutex);
- return PTR_ERR(handle);
+ err = PTR_ERR(handle);
+ goto flags_out;
}
if (IS_SYNC(inode))
handle->h_sync = 1;
@@ -110,6 +119,8 @@ flags_err:
if ((jflag ^ oldflags) & (EXT3_JOURNAL_DATA_FL))
err = ext3_change_inode_journal_flag(inode, jflag);
mutex_unlock(&inode->i_mutex);
+flags_out:
+ mnt_drop_write(filp->f_vfsmnt);
return err;
}
case EXT3_IOC_GETVERSION:
@@ -124,14 +135,18 @@ flags_err:

if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
return -EPERM;
- if (IS_RDONLY(inode))
- return -EROFS;
- if (get_user(generation, (int __user *) arg))
- return -EFAULT;
-
+ err = mnt_want_write(filp->f_vfsmnt);
+ if (err)
+ return err;
+ if (get_user(generation, (int __user *) arg)) {
+ err = -EFAULT;
+ goto setversion_out;
+ }
handle = ext3_journal_start(inode, 1);
- if (IS_ERR(handle))
- return PTR_ERR(handle);
+ if (IS_ERR(handle)) {
+ err = PTR_ERR(handle);
+ goto setversion_out;
+ }
err = ext3_reserve_inode_write(handle, inode, &iloc);
if (err == 0) {
inode->i_ctime = CURRENT_TIME_SEC;
@@ -139,6 +154,8 @@ flags_err:
err = ext3_mark_iloc_dirty(handle, inode, &iloc);
}
ext3_journal_stop(handle);
+setversion_out:
+ mnt_drop_write(filp->f_vfsmnt);
return err;
}
#ifdef CONFIG_JBD_DEBUG
@@ -174,18 +191,24 @@ flags_err:
}
return -ENOTTY;
case EXT3_IOC_SETRSVSZ: {
+ int err;

if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
return -ENOTTY;

- if (IS_RDONLY(inode))
- return -EROFS;
+ err = mnt_want_write(filp->f_vfsmnt);
+ if (err)
+ return err;

- if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
- return -EACCES;
+ if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER)) {
+ err = -EACCES;
+ goto setrsvsz_out;
+ }

- if (get_user(rsv_window_size, (int __user *)arg))
- return -EFAULT;
+ if (get_user(rsv_window_size, (int __user *)arg)) {
+ err = -EFAULT;
+ goto setrsvsz_out;
+ }

if (rsv_window_size > EXT3_MAX_RESERVE_BLOCKS)
rsv_window_size = EXT3_MAX_RESERVE_BLOCKS;
@@ -203,7 +226,9 @@ flags_err:
rsv->rsv_goal_size = rsv_window_size;
}
mutex_unlock(&ei->truncate_mutex);
- return 0;
+setrsvsz_out:
+ mnt_drop_write(filp->f_vfsmnt);
+ return err;
}
case EXT3_IOC_GROUP_EXTEND: {
ext3_fsblk_t n_blocks_count;
@@ -213,17 +238,20 @@ flags_err:
if (!capable(CAP_SYS_RESOURCE))
return -EPERM;

- if (IS_RDONLY(inode))
- return -EROFS;
-
- if (get_user(n_blocks_count, (__u32 __user *)arg))
- return -EFAULT;
+ err = mnt_want_write(filp->f_vfsmnt);
+ if (err)
+ return err;

+ if (get_user(n_blocks_count, (__u32 __user *)arg)) {
+ err = -EFAULT;
+ goto group_extend_out;
+ }
err = ext3_group_extend(sb, EXT3_SB(sb)->s_es, n_blocks_count);
journal_lock_updates(EXT3_SB(sb)->s_journal);
journal_flush(EXT3_SB(sb)->s_journal);
journal_unlock_updates(EXT3_SB(sb)->s_journal);
-
+group_extend_out:
+ mnt_drop_write(filp->f_vfsmnt);
return err;
}
case EXT3_IOC_GROUP_ADD: {
@@ -234,18 +262,22 @@ flags_err:
if (!capable(CAP_SYS_RESOURCE))
return -EPERM;

- if (IS_RDONLY(inode))
- return -EROFS;
+ err = mnt_want_write(filp->f_vfsmnt);
+ if (err)
+ return err;

if (copy_from_user(&input, (struct ext3_new_group_input __user *)arg,
- sizeof(input)))
- return -EFAULT;
+ sizeof(input))) {
+ err = -EFAULT;
+ goto group_add_out;
+ }

err = ext3_group_add(sb, &input);
journal_lock_updates(EXT3_SB(sb)->s_journal);
journal_flush(EXT3_SB(sb)->s_journal);
journal_unlock_updates(EXT3_SB(sb)->s_journal);
-
+group_add_out:
+ mnt_drop_write(filp->f_vfsmnt);
return err;
}

diff -puN fs/ext4/ioctl.c~ioctl-mnt-takers fs/ext4/ioctl.c
--- lxc/fs/ext4/ioctl.c~ioctl-mnt-takers 2007-07-10 12:46:05.000000000 -0700
+++ lxc-dave/fs/ext4/ioctl.c 2007-07-10 12:46:05.000000000 -0700
@@ -12,6 +12,7 @@
#include <linux/capability.h>
#include <linux/ext4_fs.h>
#include <linux/ext4_jbd2.h>
+#include <linux/mount.h>
#include <linux/time.h>
#include <linux/compat.h>
#include <linux/smp_lock.h>
@@ -37,15 +38,19 @@ int ext4_ioctl (struct inode * inode, st
unsigned int oldflags;
unsigned int jflag;

- if (IS_RDONLY(inode))
- return -EROFS;
-
- if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
- return -EACCES;
+ err = mnt_want_write(filp->f_vfsmnt);
+ if (err)
+ return err;

- if (get_user(flags, (int __user *) arg))
- return -EFAULT;
+ if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER)) {
+ err = -EACCES;
+ goto flags_out;
+ }

+ if (get_user(flags, (int __user *) arg)) {
+ err = -EFAULT;
+ goto flags_out;
+ }
if (!S_ISDIR(inode->i_mode))
flags &= ~EXT4_DIRSYNC_FL;

@@ -64,7 +69,8 @@ int ext4_ioctl (struct inode * inode, st
if ((flags ^ oldflags) & (EXT4_APPEND_FL | EXT4_IMMUTABLE_FL)) {
if (!capable(CAP_LINUX_IMMUTABLE)) {
mutex_unlock(&inode->i_mutex);
- return -EPERM;
+ err = -EPERM;
+ goto flags_out;
}
}

@@ -75,7 +81,8 @@ int ext4_ioctl (struct inode * inode, st
if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL)) {
if (!capable(CAP_SYS_RESOURCE)) {
mutex_unlock(&inode->i_mutex);
- return -EPERM;
+ err = -EPERM;
+ goto flags_out;
}
}

@@ -83,7 +90,8 @@ int ext4_ioctl (struct inode * inode, st
handle = ext4_journal_start(inode, 1);
if (IS_ERR(handle)) {
mutex_unlock(&inode->i_mutex);
- return PTR_ERR(handle);
+ err = PTR_ERR(handle);
+ goto flags_out;
}
if (IS_SYNC(inode))
handle->h_sync = 1;
@@ -103,12 +111,14 @@ flags_err:
ext4_journal_stop(handle);
if (err) {
mutex_unlock(&inode->i_mutex);
- return err;
+ goto flags_out;
}

if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL))
err = ext4_change_inode_journal_flag(inode, jflag);
mutex_unlock(&inode->i_mutex);
+flags_out:
+ mnt_drop_write(filp->f_vfsmnt);
return err;
}
case EXT4_IOC_GETVERSION:
@@ -123,14 +133,18 @@ flags_err:

if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
return -EPERM;
- if (IS_RDONLY(inode))
- return -EROFS;
- if (get_user(generation, (int __user *) arg))
- return -EFAULT;
-
+ err = mnt_want_write(filp->f_vfsmnt);
+ if (err)
+ return err;
+ if (get_user(generation, (int __user *) arg)) {
+ err = -EFAULT;
+ goto setversion_out;
+ }
handle = ext4_journal_start(inode, 1);
- if (IS_ERR(handle))
- return PTR_ERR(handle);
+ if (IS_ERR(handle)) {
+ err = PTR_ERR(handle);
+ goto setversion_out;
+ }
err = ext4_reserve_inode_write(handle, inode, &iloc);
if (err == 0) {
inode->i_ctime = CURRENT_TIME_SEC;
@@ -138,6 +152,8 @@ flags_err:
err = ext4_mark_iloc_dirty(handle, inode, &iloc);
}
ext4_journal_stop(handle);
+setversion_out:
+ mnt_drop_write(filp->f_vfsmnt);
return err;
}
#ifdef CONFIG_JBD_DEBUG
@@ -173,19 +189,23 @@ flags_err:
}
return -ENOTTY;
case EXT4_IOC_SETRSVSZ: {
+ int err;

if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
return -ENOTTY;

- if (IS_RDONLY(inode))
- return -EROFS;
-
- if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
- return -EACCES;
-
- if (get_user(rsv_window_size, (int __user *)arg))
- return -EFAULT;
+ err = mnt_want_write(filp->f_vfsmnt);
+ if (err)
+ return err;

+ if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER)) {
+ err = -EACCES;
+ goto setrsvsz_out;
+ }
+ if (get_user(rsv_window_size, (int __user *)arg)) {
+ err = -EFAULT;
+ goto setrsvsz_out;
+ }
if (rsv_window_size > EXT4_MAX_RESERVE_BLOCKS)
rsv_window_size = EXT4_MAX_RESERVE_BLOCKS;

@@ -202,7 +222,9 @@ flags_err:
rsv->rsv_goal_size = rsv_window_size;
}
mutex_unlock(&ei->truncate_mutex);
- return 0;
+setrsvsz_out:
+ mnt_drop_write(filp->f_vfsmnt);
+ return err;
}
case EXT4_IOC_GROUP_EXTEND: {
ext4_fsblk_t n_blocks_count;
@@ -212,17 +234,21 @@ flags_err:
if (!capable(CAP_SYS_RESOURCE))
return -EPERM;

- if (IS_RDONLY(inode))
- return -EROFS;
-
- if (get_user(n_blocks_count, (__u32 __user *)arg))
- return -EFAULT;
+ err = mnt_want_write(filp->f_vfsmnt);
+ if (err)
+ return err;

+ if (get_user(n_blocks_count, (__u32 __user *)arg)) {
+ err = -EFAULT;
+ goto group_extend_out;
+ }
err = ext4_group_extend(sb, EXT4_SB(sb)->s_es, n_blocks_count);
jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
jbd2_journal_flush(EXT4_SB(sb)->s_journal);
jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);

+group_extend_out:
+ mnt_drop_write(filp->f_vfsmnt);
return err;
}
case EXT4_IOC_GROUP_ADD: {
@@ -233,18 +259,21 @@ flags_err:
if (!capable(CAP_SYS_RESOURCE))
return -EPERM;

- if (IS_RDONLY(inode))
- return -EROFS;
+ err = mnt_want_write(filp->f_vfsmnt);
+ if (err)
+ return err;

if (copy_from_user(&input, (struct ext4_new_group_input __user *)arg,
- sizeof(input)))
- return -EFAULT;
-
+ sizeof(input))) {
+ err = -EFAULT;
+ goto group_add_out;
+ }
err = ext4_group_add(sb, &input);
jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
jbd2_journal_flush(EXT4_SB(sb)->s_journal);
jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
-
+group_add_out:
+ mnt_drop_write(filp->f_vfsmnt);
return err;
}

diff -puN fs/fat/file.c~ioctl-mnt-takers fs/fat/file.c
--- lxc/fs/fat/file.c~ioctl-mnt-takers 2007-07-10 12:46:05.000000000 -0700
+++ lxc-dave/fs/fat/file.c 2007-07-10 12:46:05.000000000 -0700
@@ -8,6 +8,7 @@

#include <linux/capability.h>
#include <linux/module.h>
+#include <linux/mount.h>
#include <linux/time.h>
#include <linux/msdos_fs.h>
#include <linux/smp_lock.h>
@@ -46,10 +47,9 @@ int fat_generic_ioctl(struct inode *inod

mutex_lock(&inode->i_mutex);

- if (IS_RDONLY(inode)) {
- err = -EROFS;
- goto up;
- }
+ err = mnt_want_write(filp->f_vfsmnt);
+ if (err)
+ goto up_no_drop_write;

/*
* ATTR_VOLUME and ATTR_DIR cannot be changed; this also
@@ -106,6 +106,8 @@ int fat_generic_ioctl(struct inode *inod
MSDOS_I(inode)->i_attrs = attr & ATTR_UNUSED;
mark_inode_dirty(inode);
up:
+ mnt_drop_write(filp->f_vfsmnt);
+ up_no_drop_write:
mutex_unlock(&inode->i_mutex);
return err;
}
diff -puN fs/hfsplus/ioctl.c~ioctl-mnt-takers fs/hfsplus/ioctl.c
--- lxc/fs/hfsplus/ioctl.c~ioctl-mnt-takers 2007-07-10 12:46:05.000000000 -0700
+++ lxc-dave/fs/hfsplus/ioctl.c 2007-07-10 12:46:05.000000000 -0700
@@ -35,25 +35,32 @@ int hfsplus_ioctl(struct inode *inode, s
flags |= FS_NODUMP_FL; /* EXT2_NODUMP_FL */
return put_user(flags, (int __user *)arg);
case HFSPLUS_IOC_EXT2_SETFLAGS: {
- if (IS_RDONLY(inode))
- return -EROFS;
-
- if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
- return -EACCES;
-
- if (get_user(flags, (int __user *)arg))
- return -EFAULT;
-
+ int err = 0;
+ err = mnt_want_write(filp->f_vfsmnt);
+ if (err)
+ return err;
+
+ if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER)) {
+ err = -EACCES;
+ goto setflags_out;
+ }
+ if (get_user(flags, (int __user *)arg)) {
+ err = -EFAULT;
+ goto setflags_out;
+ }
if (flags & (FS_IMMUTABLE_FL|FS_APPEND_FL) ||
HFSPLUS_I(inode).rootflags & (HFSPLUS_FLG_IMMUTABLE|HFSPLUS_FLG_APPEND)) {
- if (!capable(CAP_LINUX_IMMUTABLE))
- return -EPERM;
+ if (!capable(CAP_LINUX_IMMUTABLE)) {
+ err = -EPERM;
+ goto setflags_out;
+ }
}

/* don't silently ignore unsupported ext2 flags */
- if (flags & ~(FS_IMMUTABLE_FL|FS_APPEND_FL|FS_NODUMP_FL))
- return -EOPNOTSUPP;
-
+ if (flags & ~(FS_IMMUTABLE_FL|FS_APPEND_FL|FS_NODUMP_FL)) {
+ err = -EOPNOTSUPP;
+ goto setflags_out;
+ }
if (flags & FS_IMMUTABLE_FL) { /* EXT2_IMMUTABLE_FL */
inode->i_flags |= S_IMMUTABLE;
HFSPLUS_I(inode).rootflags |= HFSPLUS_FLG_IMMUTABLE;
@@ -75,7 +82,9 @@ int hfsplus_ioctl(struct inode *inode, s

inode->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(inode);
- return 0;
+setflags_out:
+ mnt_drop_write(filp->f_vfsmnt);
+ return err;
}
default:
return -ENOTTY;
diff -puN fs/jfs/ioctl.c~ioctl-mnt-takers fs/jfs/ioctl.c
--- lxc/fs/jfs/ioctl.c~ioctl-mnt-takers 2007-07-10 12:46:05.000000000 -0700
+++ lxc-dave/fs/jfs/ioctl.c 2007-07-10 12:46:05.000000000 -0700
@@ -8,6 +8,7 @@
#include <linux/fs.h>
#include <linux/ctype.h>
#include <linux/capability.h>
+#include <linux/mount.h>
#include <linux/time.h>
#include <linux/sched.h>
#include <asm/current.h>
@@ -65,16 +66,20 @@ int jfs_ioctl(struct inode * inode, stru
return put_user(flags, (int __user *) arg);
case JFS_IOC_SETFLAGS: {
unsigned int oldflags;
+ int err;

- if (IS_RDONLY(inode))
- return -EROFS;
-
- if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
- return -EACCES;
-
- if (get_user(flags, (int __user *) arg))
- return -EFAULT;
-
+ err = mnt_want_write(filp->f_vfsmnt);
+ if (err)
+ return err;
+
+ if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER)) {
+ err = -EACCES;
+ goto setflags_out;
+ }
+ if (get_user(flags, (int __user *) arg)) {
+ err = -EFAULT;
+ goto setflags_out;
+ }
flags = jfs_map_ext2(flags, 1);
if (!S_ISDIR(inode->i_mode))
flags &= ~JFS_DIRSYNC_FL;
@@ -89,8 +94,10 @@ int jfs_ioctl(struct inode * inode, stru
if ((oldflags & JFS_IMMUTABLE_FL) ||
((flags ^ oldflags) &
(JFS_APPEND_FL | JFS_IMMUTABLE_FL))) {
- if (!capable(CAP_LINUX_IMMUTABLE))
- return -EPERM;
+ if (!capable(CAP_LINUX_IMMUTABLE)) {
+ err = -EPERM;
+ goto setflags_out;
+ }
}

flags = flags & JFS_FL_USER_MODIFIABLE;
@@ -100,7 +107,9 @@ int jfs_ioctl(struct inode * inode, stru
jfs_set_inode_flags(inode);
inode->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(inode);
- return 0;
+setflags_out:
+ mnt_drop_write(filp->f_vfsmnt);
+ return err;
}
default:
return -ENOTTY;
diff -puN fs/ocfs2/ioctl.c~ioctl-mnt-takers fs/ocfs2/ioctl.c
--- lxc/fs/ocfs2/ioctl.c~ioctl-mnt-takers 2007-07-10 12:46:05.000000000 -0700
+++ lxc-dave/fs/ocfs2/ioctl.c 2007-07-10 12:46:05.000000000 -0700
@@ -57,10 +57,6 @@ static int ocfs2_set_inode_attr(struct i
goto bail;
}

- status = -EROFS;
- if (IS_RDONLY(inode))
- goto bail_unlock;
-
status = -EACCES;
if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
goto bail_unlock;
@@ -128,8 +124,13 @@ int ocfs2_ioctl(struct inode * inode, st
if (get_user(flags, (int __user *) arg))
return -EFAULT;

- return ocfs2_set_inode_attr(inode, flags,
+ status = mnt_want_write(filp->f_vfsmnt);
+ if (status)
+ return status;
+ status = ocfs2_set_inode_attr(inode, flags,
OCFS2_FL_MODIFIABLE);
+ mnt_drop_write(filp->f_vfsmnt);
+ return status;
default:
return -ENOTTY;
}
diff -puN fs/reiserfs/ioctl.c~ioctl-mnt-takers fs/reiserfs/ioctl.c
--- lxc/fs/reiserfs/ioctl.c~ioctl-mnt-takers 2007-07-10 12:46:05.000000000 -0700
+++ lxc-dave/fs/reiserfs/ioctl.c 2007-07-10 12:46:05.000000000 -0700
@@ -4,6 +4,7 @@

#include <linux/capability.h>
#include <linux/fs.h>
+#include <linux/mount.h>
#include <linux/reiserfs_fs.h>
#include <linux/time.h>
#include <asm/uaccess.h>
@@ -25,6 +26,7 @@ int reiserfs_ioctl(struct inode *inode,
unsigned long arg)
{
unsigned int flags;
+ int err = 0;

switch (cmd) {
case REISERFS_IOC_UNPACK:
@@ -48,48 +50,61 @@ int reiserfs_ioctl(struct inode *inode,
if (!reiserfs_attrs(inode->i_sb))
return -ENOTTY;

- if (IS_RDONLY(inode))
- return -EROFS;
+ err = mnt_want_write(filp->f_vfsmnt);
+ if (err)
+ return err;

if ((current->fsuid != inode->i_uid)
- && !capable(CAP_FOWNER))
- return -EPERM;
-
- if (get_user(flags, (int __user *)arg))
- return -EFAULT;
-
+ && !capable(CAP_FOWNER)) {
+ err = -EPERM;
+ goto setflags_out;
+ }
+ if (get_user(flags, (int __user *)arg)) {
+ err = -EFAULT;
+ goto setflags_out;
+ }
if (((flags ^ REISERFS_I(inode)->
i_attrs) & (REISERFS_IMMUTABLE_FL |
REISERFS_APPEND_FL))
- && !capable(CAP_LINUX_IMMUTABLE))
- return -EPERM;
-
+ && !capable(CAP_LINUX_IMMUTABLE)) {
+ err = -EPERM;
+ goto setflags_out;
+ }
if ((flags & REISERFS_NOTAIL_FL) &&
S_ISREG(inode->i_mode)) {
int result;

result = reiserfs_unpack(inode, filp);
- if (result)
- return result;
+ if (result) {
+ err = result;
+ goto setflags_out;
+ }
}
sd_attrs_to_i_attrs(flags, inode);
REISERFS_I(inode)->i_attrs = flags;
inode->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(inode);
- return 0;
+setflags_out:
+ mnt_drop_write(filp->f_vfsmnt);
+ return err;
}
case REISERFS_IOC_GETVERSION:
return put_user(inode->i_generation, (int __user *)arg);
case REISERFS_IOC_SETVERSION:
if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
return -EPERM;
- if (IS_RDONLY(inode))
- return -EROFS;
- if (get_user(inode->i_generation, (int __user *)arg))
- return -EFAULT;
+ err = mnt_want_write(filp->f_vfsmnt);
+ if (err)
+ return err;
+ if (get_user(inode->i_generation, (int __user *)arg)) {
+ err = -EFAULT;
+ goto setversion_out;
+ }
inode->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(inode);
- return 0;
+setversion_out:
+ mnt_drop_write(filp->f_vfsmnt);
+ return err;
default:
return -ENOTTY;
}
diff -puN fs/xfs/linux-2.6/xfs_ioctl.c~ioctl-mnt-takers fs/xfs/linux-2.6/xfs_ioctl.c
--- lxc/fs/xfs/linux-2.6/xfs_ioctl.c~ioctl-mnt-takers 2007-07-10 12:46:05.000000000 -0700
+++ lxc-dave/fs/xfs/linux-2.6/xfs_ioctl.c 2007-07-10 12:46:05.000000000 -0700
@@ -526,8 +526,6 @@ xfs_attrmulti_attr_set(
char *kbuf;
int error = EFAULT;

- if (IS_RDONLY(&vp->v_inode))
- return -EROFS;
if (IS_IMMUTABLE(&vp->v_inode) || IS_APPEND(&vp->v_inode))
return EPERM;
if (len > XATTR_SIZE_MAX)
@@ -553,8 +551,6 @@ xfs_attrmulti_attr_remove(
char *name,
__uint32_t flags)
{
- if (IS_RDONLY(&vp->v_inode))
- return -EROFS;
if (IS_IMMUTABLE(&vp->v_inode) || IS_APPEND(&vp->v_inode))
return EPERM;
return bhv_vop_attr_remove(vp, name, flags, NULL);
@@ -564,6 +560,7 @@ STATIC int
xfs_attrmulti_by_handle(
xfs_mount_t *mp,
void __user *arg,
+ struct file *parfilp,
struct inode *parinode)
{
int error;
@@ -618,13 +615,21 @@ xfs_attrmulti_by_handle(
&ops[i].am_length, ops[i].am_flags);
break;
case ATTR_OP_SET:
+ ops[i].am_error = mnt_want_write(parfilp->f_vfsmnt);
+ if (ops[i].am_error)
+ break;
ops[i].am_error = xfs_attrmulti_attr_set(vp,
attr_name, ops[i].am_attrvalue,
ops[i].am_length, ops[i].am_flags);
+ mnt_drop_write(parfilp->f_vfsmnt);
break;
case ATTR_OP_REMOVE:
+ ops[i].am_error = mnt_want_write(parfilp->f_vfsmnt);
+ if (ops[i].am_error)
+ break;
ops[i].am_error = xfs_attrmulti_attr_remove(vp,
attr_name, ops[i].am_flags);
+ mnt_drop_write(parfilp->f_vfsmnt);
break;
default:
ops[i].am_error = EINVAL;
@@ -804,7 +809,7 @@ xfs_ioctl(
return xfs_attrlist_by_handle(mp, arg, inode);

case XFS_IOC_ATTRMULTI_BY_HANDLE:
- return xfs_attrmulti_by_handle(mp, arg, inode);
+ return xfs_attrmulti_by_handle(mp, arg, filp, inode);

case XFS_IOC_SWAPEXT: {
error = xfs_swapext((struct xfs_swapext __user *)arg);
diff -puN fs/xfs/linux-2.6/xfs_iops.c~ioctl-mnt-takers fs/xfs/linux-2.6/xfs_iops.c
--- lxc/fs/xfs/linux-2.6/xfs_iops.c~ioctl-mnt-takers 2007-07-10 12:46:05.000000000 -0700
+++ lxc-dave/fs/xfs/linux-2.6/xfs_iops.c 2007-07-10 12:46:05.000000000 -0700
@@ -156,13 +156,6 @@ xfs_ichgtime_fast(
*/
ASSERT((flags & XFS_ICHGTIME_ACC) == 0);

- /*
- * We're not supposed to change timestamps in readonly-mounted
- * filesystems. Throw it away if anyone asks us.
- */
- if (unlikely(IS_RDONLY(inode)))
- return;
-
if (flags & XFS_ICHGTIME_MOD) {
tvp = &inode->i_mtime;
ip->i_d.di_mtime.t_sec = (__int32_t)tvp->tv_sec;
diff -puN fs/xfs/linux-2.6/xfs_lrw.c~ioctl-mnt-takers fs/xfs/linux-2.6/xfs_lrw.c
--- lxc/fs/xfs/linux-2.6/xfs_lrw.c~ioctl-mnt-takers 2007-07-10 12:46:05.000000000 -0700
+++ lxc-dave/fs/xfs/linux-2.6/xfs_lrw.c 2007-07-10 12:46:05.000000000 -0700
@@ -50,6 +50,7 @@
#include "xfs_iomap.h"

#include <linux/capability.h>
+#include <linux/mount.h>
#include <linux/writeback.h>

@@ -761,10 +762,16 @@ start:
if (new_size > xip->i_size)
io->io_new_size = new_size;

- if (likely(!(ioflags & IO_INVIS))) {
+ /*
+ * We're not supposed to change timestamps in readonly-mounted
+ * filesystems. Throw it away if anyone asks us.
+ */
+ if (likely(!(ioflags & IO_INVIS) &&
+ !mnt_want_write(file->f_vfsmnt))) {
file_update_time(file);
xfs_ichgtime_fast(xip, inode,
XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
+ mnt_drop_write(file->f_vfsmnt);
}

/*
_