1 files changed, 36 insertions, 12 deletions

diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 19a8ca4ab1dd..19892d7d2ed1 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -822,18 +822,6 @@ static int truncate_upper(struct dentry *dentry, struct iattr *ia,
                 size_t num_zeros = (PAGE_CACHE_SIZE
                                     - (ia->ia_size & ~PAGE_CACHE_MASK));
 
-
-                /*
-                 * XXX(truncate) this should really happen at the begginning
-                 * of ->setattr.  But the code is too messy to that as part
-                 * of a larger patch.  ecryptfs is also totally missing out
-                 * on the inode_change_ok check at the beginning of
-                 * ->setattr while would include this.
-                 */
-                rc = inode_newsize_ok(inode, ia->ia_size);
-                if (rc)
-                        goto out;
-
                 if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
                         truncate_setsize(inode, ia->ia_size);
                         lower_ia->ia_size = ia->ia_size;
@@ -883,6 +871,28 @@ out:
         return rc;
 }
 
+static int ecryptfs_inode_newsize_ok(struct inode *inode, loff_t offset)
+{
+        struct ecryptfs_crypt_stat *crypt_stat;
+        loff_t lower_oldsize, lower_newsize;
+
+        crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
+        lower_oldsize = upper_size_to_lower_size(crypt_stat,
+                                                 i_size_read(inode));
+        lower_newsize = upper_size_to_lower_size(crypt_stat, offset);
+        if (lower_newsize > lower_oldsize) {
+                /*
+                 * The eCryptfs inode and the new *lower* size are mixed here
+                 * because we may not have the lower i_mutex held and/or it may
+                 * not be appropriate to call inode_newsize_ok() with inodes
+                 * from other filesystems.
+                 */
+                return inode_newsize_ok(inode, lower_newsize);
+        }
+
+        return 0;
+}
+
 /**
  * ecryptfs_truncate
  * @dentry: The ecryptfs layer dentry
@@ -899,6 +909,10 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
         struct iattr lower_ia = { .ia_valid = 0 };
         int rc;
 
+        rc = ecryptfs_inode_newsize_ok(dentry->d_inode, new_length);
+        if (rc)
+                return rc;
+
         rc = truncate_upper(dentry, &ia, &lower_ia);
         if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
                 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
@@ -978,6 +992,16 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
                 }
         }
         mutex_unlock(&crypt_stat->cs_mutex);
+
+        rc = inode_change_ok(inode, ia);
+        if (rc)
+                goto out;
+        if (ia->ia_valid & ATTR_SIZE) {
+                rc = ecryptfs_inode_newsize_ok(inode, ia->ia_size);
+                if (rc)
+                        goto out;
+        }
+
         if (S_ISREG(inode->i_mode)) {
                 rc = filemap_write_and_wait(inode->i_mapping);
                 if (rc)