fuse: fix stat call on 32 bit platforms

Now we store attr->ino at inode->i_ino, return attr->ino at the
first time and then return inode->i_ino if the attribute timeout
isn't expired. That's wrong on 32 bit platforms because attr->ino
is 64 bit and inode->i_ino is 32 bit in this case.

Fix this by saving 64 bit ino in fuse_inode structure and returning
it every time we call getattr. Also squash attr->ino into inode->i_ino
explicitly.

Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

3 files changed, 20 insertions, 1 deletions

diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index df5ac048dc74..bc438320cac5 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -863,6 +863,7 @@ int fuse_update_attributes(struct inode *inode, struct kstat *stat,
                 if (stat) {
                         generic_fillattr(inode, stat);
                         stat->mode = fi->orig_i_mode;
+                        stat->ino = fi->orig_ino;
                 }
         }
 
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index f38fb795f03c..771fb6322c07 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -82,6 +82,9 @@ struct fuse_inode {
             preserve the original mode */
         umode_t orig_i_mode;
 
+        /** 64 bit inode number */
+        u64 orig_ino;
+
         /** Version of last attribute change */
         u64 attr_version;
 
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 26783eb2b1fc..a59cf5e673d7 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -91,6 +91,7 @@ static struct inode *fuse_alloc_inode(struct super_block *sb)
         fi->nlookup = 0;
         fi->attr_version = 0;
         fi->writectr = 0;
+        fi->orig_ino = 0;
         INIT_LIST_HEAD(&fi->write_files);
         INIT_LIST_HEAD(&fi->queued_writes);
         INIT_LIST_HEAD(&fi->writepages);
@@ -139,6 +140,18 @@ static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
         return 0;
 }
 
+/*
+ * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down
+ * so that it will fit.
+ */
+static ino_t fuse_squash_ino(u64 ino64)
+{
+        ino_t ino = (ino_t) ino64;
+        if (sizeof(ino_t) < sizeof(u64))
+                ino ^= ino64 >> (sizeof(u64) - sizeof(ino_t)) * 8;
+        return ino;
+}
+
 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
                                    u64 attr_valid)
 {
@@ -148,7 +161,7 @@ void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
         fi->attr_version = ++fc->attr_version;
         fi->i_time = attr_valid;
 
-        inode->i_ino     = attr->ino;
+        inode->i_ino     = fuse_squash_ino(attr->ino);
         inode->i_mode    = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
         set_nlink(inode, attr->nlink);
         inode->i_uid     = attr->uid;
@@ -174,6 +187,8 @@ void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
         fi->orig_i_mode = inode->i_mode;
         if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
                 inode->i_mode &= ~S_ISVTX;
+
+        fi->orig_ino = attr->ino;
 }
 
 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,