diff options
Diffstat (limited to 'fs/open.c')
| -rw-r--r-- | fs/open.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/fs/open.c b/fs/open.c index 648fb9d3e97a..8aeb08bb278b 100644 --- a/fs/open.c +++ b/fs/open.c @@ -68,6 +68,7 @@ int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs, long vfs_truncate(const struct path *path, loff_t length) { struct inode *inode; + struct dentry *upperdentry; long error; inode = path->dentry->d_inode; @@ -90,7 +91,17 @@ long vfs_truncate(const struct path *path, loff_t length) if (IS_APPEND(inode)) goto mnt_drop_write_and_out; - error = get_write_access(inode); + /* + * If this is an overlayfs then do as if opening the file so we get + * write access on the upper inode, not on the overlay inode. For + * non-overlay filesystems d_real() is an identity function. + */ + upperdentry = d_real(path->dentry, NULL, O_WRONLY); + error = PTR_ERR(upperdentry); + if (IS_ERR(upperdentry)) + goto mnt_drop_write_and_out; + + error = get_write_access(upperdentry->d_inode); if (error) goto mnt_drop_write_and_out; @@ -109,7 +120,7 @@ long vfs_truncate(const struct path *path, loff_t length) error = do_truncate(path->dentry, length, 0, NULL); put_write_and_out: - put_write_access(inode); + put_write_access(upperdentry->d_inode); mnt_drop_write_and_out: mnt_drop_write(path->mnt); out: |
