commit 66b87fe08beffaddbd8a9e3b071ef7520eefa8fd
Author: Erez Zadok <[EMAIL PROTECTED]>
Date: Fri Nov 16 13:45:24 2007 -0500
Unionfs: cleanup permission checking code
Use vfs helpers and avoid redundant checks performed by the VFS already.
Signed-off-by: Erez Zadok <[EMAIL PROTECTED]>
diff --git a/fs/unionfs/commonfops.c b/fs/unionfs/commonfops.c
index 15d160b..50c83bb 100644
--- a/fs/unionfs/commonfops.c
+++ b/fs/unionfs/commonfops.c
@@ -746,10 +746,6 @@ static long do_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
lower_file = unionfs_lower_file(file);
- err = security_file_ioctl(lower_file, cmd, arg);
- if (err)
- goto out;
-
err = -ENOTTY;
if (!lower_file || !lower_file->f_op)
goto out;
diff --git a/fs/unionfs/inode.c b/fs/unionfs/inode.c
index 22edc11..3ad08d8 100644
--- a/fs/unionfs/inode.c
+++ b/fs/unionfs/inode.c
@@ -733,59 +733,6 @@ static void unionfs_put_link(struct dentry *dentry, struct
nameidata *nd,
}
/*
- * Basically copied from the kernel vfs permission(), but we've changed
- * the following:
- * (1) the IS_RDONLY check is skipped, and
- * (2) We return 0 (success) if the non-leftmost branch is mounted
- * readonly, to allow copyup to work.
- * (3) we do call security_inode_permission, and therefore security inside
- * SELinux, etc. are performed.
- *
- * @inode: the lower inode we're checking permission on
- */
-static int inode_permission(struct super_block *sb, struct inode *inode,
- int mask, struct nameidata *nd, int bindex)
-{
- int retval, submask;
-
- if (mask & MAY_WRITE) {
- umode_t mode = inode->i_mode;
- /* The first branch is allowed to be really readonly. */
- if (bindex == 0 &&
- IS_RDONLY(inode) &&
- (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)))
- return -EROFS;
- /*
- * Nobody gets write access to an immutable file.
- */
- if (IS_IMMUTABLE(inode))
- return -EACCES;
- /*
- * For all other branches than the first one, we ignore
- * EROFS or if the branch is mounted as readonly, to let
- * copyup take place.
- */
- if (bindex > 0 &&
- is_robranch_super(sb, bindex) &&
- (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)))
- return 0;
- }
-
- /* Ordinary permission routines do not understand MAY_APPEND. */
- submask = mask & ~MAY_APPEND;
- if (inode->i_op && inode->i_op->permission)
- retval = inode->i_op->permission(inode, submask, nd);
- else
- retval = generic_permission(inode, submask, NULL);
-
- if (retval && retval != -EROFS) /* ignore EROFS */
- return retval;
-
- retval = security_inode_permission(inode, mask, nd);
- return ((retval == -EROFS) ? 0 : retval); /* ignore EROFS */
-}
-
-/*
* Don't grab the superblock read-lock in unionfs_permission, which prevents
* a deadlock with the branch-management "add branch" code (which grabbed
* the write lock). It is safe to not grab the read lock here, because even
@@ -830,11 +777,20 @@ static int unionfs_permission(struct inode *inode, int
mask,
continue;
/*
- * We use our own special version of permission, such that
- * only the first branch returns -EROFS.
+ * We check basic permissions, but we ignore any conditions
+ * such as readonly file systems or branches marked as
+ * readonly, because those conditions should lead to a
+ * copyup taking place later on.
*/
- err = inode_permission(inode->i_sb, lower_inode, mask, nd,
- bindex);
+ err = permission(lower_inode, mask, nd);
+ if (err && bindex > 0) {
+ umode_t mode = lower_inode->i_mode;
+ if (is_robranch_super(inode->i_sb, bindex) &&
+ (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)))
+ err = 0;
+ if (IS_COPYUP_ERR(err))
+ err = 0;
+ }
/*
* The permissions are an intersection of the overall directory
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