[016/111] eCryptfs: Handle ioctl calls with unlocked and compat functions

From: Greg KH
Date: Wed Aug 11 2010 - 20:42:55 EST


2.6.32-stable review patch. If anyone has any objections, please let us know.

------------------

From: Tyler Hicks <tyhicks@xxxxxxxxxxxxxxxxxx>

commit c43f7b8fb03be8bcc579bfc4e6ab70eac887ab55 upstream.

Lower filesystems that only implemented unlocked_ioctl weren't being
passed ioctl calls because eCryptfs only checked for
lower_file->f_op->ioctl and returned -ENOTTY if it was NULL.

eCryptfs shouldn't implement ioctl(), since it doesn't require the BKL.
This patch introduces ecryptfs_unlocked_ioctl() and
ecryptfs_compat_ioctl(), which passes the calls on to the lower file
system.

https://bugs.launchpad.net/ecryptfs/+bug/469664

Reported-by: James Dupin <james.dupin@xxxxxxxxx>
Signed-off-by: Tyler Hicks <tyhicks@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
fs/ecryptfs/file.c | 56 +++++++++++++++++++++++++++++++++--------------------
1 file changed, 35 insertions(+), 21 deletions(-)

--- a/fs/ecryptfs/file.c
+++ b/fs/ecryptfs/file.c
@@ -293,12 +293,40 @@ static int ecryptfs_fasync(int fd, struc
return rc;
}

-static int ecryptfs_ioctl(struct inode *inode, struct file *file,
- unsigned int cmd, unsigned long arg);
+static long
+ecryptfs_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ struct file *lower_file = NULL;
+ long rc = -ENOTTY;
+
+ if (ecryptfs_file_to_private(file))
+ lower_file = ecryptfs_file_to_lower(file);
+ if (lower_file && lower_file->f_op && lower_file->f_op->unlocked_ioctl)
+ rc = lower_file->f_op->unlocked_ioctl(lower_file, cmd, arg);
+ return rc;
+}
+
+#ifdef CONFIG_COMPAT
+static long
+ecryptfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ struct file *lower_file = NULL;
+ long rc = -ENOIOCTLCMD;
+
+ if (ecryptfs_file_to_private(file))
+ lower_file = ecryptfs_file_to_lower(file);
+ if (lower_file && lower_file->f_op && lower_file->f_op->compat_ioctl)
+ rc = lower_file->f_op->compat_ioctl(lower_file, cmd, arg);
+ return rc;
+}
+#endif

const struct file_operations ecryptfs_dir_fops = {
.readdir = ecryptfs_readdir,
- .ioctl = ecryptfs_ioctl,
+ .unlocked_ioctl = ecryptfs_unlocked_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = ecryptfs_compat_ioctl,
+#endif
.mmap = generic_file_mmap,
.open = ecryptfs_open,
.flush = ecryptfs_flush,
@@ -315,7 +343,10 @@ const struct file_operations ecryptfs_ma
.write = do_sync_write,
.aio_write = generic_file_aio_write,
.readdir = ecryptfs_readdir,
- .ioctl = ecryptfs_ioctl,
+ .unlocked_ioctl = ecryptfs_unlocked_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = ecryptfs_compat_ioctl,
+#endif
.mmap = generic_file_mmap,
.open = ecryptfs_open,
.flush = ecryptfs_flush,
@@ -324,20 +355,3 @@ const struct file_operations ecryptfs_ma
.fasync = ecryptfs_fasync,
.splice_read = generic_file_splice_read,
};
-
-static int
-ecryptfs_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
- unsigned long arg)
-{
- int rc = 0;
- struct file *lower_file = NULL;
-
- if (ecryptfs_file_to_private(file))
- lower_file = ecryptfs_file_to_lower(file);
- if (lower_file && lower_file->f_op && lower_file->f_op->ioctl)
- rc = lower_file->f_op->ioctl(ecryptfs_inode_to_lower(inode),
- lower_file, cmd, arg);
- else
- rc = -ENOTTY;
- return rc;
-}


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