don't bother with {get,put}_write_access() on non-regular files

it's pointless and actually leads to wrong behaviour in at least one
moderately convoluted case (pipe(), close one end, try to get to
another via /proc/*/fd and run into ETXTBUSY).

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/file_table.c b/fs/file_table.c
index 5b24008ea4f6..79ecae62209a 100644
--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -209,10 +209,10 @@ static void drop_file_write_access(struct file *file)
         struct dentry *dentry = file->f_path.dentry;
         struct inode *inode = dentry->d_inode;
 
-        put_write_access(inode);
-
         if (special_file(inode->i_mode))
                 return;
+
+        put_write_access(inode);
         if (file_check_writeable(file) != 0)
                 return;
         __mnt_drop_write(mnt);