diff options
| author | Dave Hansen <haveblue@us.ibm.com> | 2008-02-16 01:37:46 +0300 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2008-04-19 08:29:24 +0400 |
| commit | 42a74f206b914db13ee1f5ae932dcd91a77c8579 (patch) | |
| tree | 24e3dbe55edaacc750067ab9e01778255a6bff08 /fs/jfs | |
| parent | 20ddee2c75339cc095f6191c3115f81da8955e96 (diff) | |
| download | linux-42a74f206b914db13ee1f5ae932dcd91a77c8579.tar.xz | |
[PATCH] r/o bind mounts: elevate write count for ioctls()
Some ioctl()s can cause writes to the filesystem. Take these, and make them
use mnt_want/drop_write() instead.
[AV: updated]
Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/jfs')
| -rw-r--r-- | fs/jfs/ioctl.c | 33 |
1 files changed, 22 insertions, 11 deletions
diff --git a/fs/jfs/ioctl.c b/fs/jfs/ioctl.c index a1f8e375ad21..afe222bf300f 100644 --- a/fs/jfs/ioctl.c +++ b/fs/jfs/ioctl.c @@ -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> @@ -65,23 +66,30 @@ long jfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) return put_user(flags, (int __user *) arg); case JFS_IOC_SETFLAGS: { unsigned int oldflags; + int err; - if (IS_RDONLY(inode)) - return -EROFS; + err = mnt_want_write(filp->f_path.mnt); + if (err) + return err; - if (!is_owner_or_cap(inode)) - return -EACCES; - - if (get_user(flags, (int __user *) arg)) - return -EFAULT; + if (!is_owner_or_cap(inode)) { + 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; /* Is it quota file? Do not allow user to mess with it */ - if (IS_NOQUOTA(inode)) - return -EPERM; + if (IS_NOQUOTA(inode)) { + err = -EPERM; + goto setflags_out; + } /* Lock against other parallel changes of flags */ mutex_lock(&inode->i_mutex); @@ -98,7 +106,8 @@ long jfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) (JFS_APPEND_FL | JFS_IMMUTABLE_FL))) { if (!capable(CAP_LINUX_IMMUTABLE)) { mutex_unlock(&inode->i_mutex); - return -EPERM; + err = -EPERM; + goto setflags_out; } } @@ -110,7 +119,9 @@ long jfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) mutex_unlock(&inode->i_mutex); inode->i_ctime = CURRENT_TIME_SEC; mark_inode_dirty(inode); - return 0; +setflags_out: + mnt_drop_write(filp->f_path.mnt); + return err; } default: return -ENOTTY; |