linux-kernel - [PATCH 4.2.y-ckt 053/305] fix sysvfs symlinks

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Message-Id: <1452902519-2754-54-git-send-email-kamal@canonical.com>
Date:	Fri, 15 Jan 2016 15:57:47 -0800
From:	Kamal Mostafa <kamal@...onical.com>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org,
	kernel-team@...ts.ubuntu.com
Cc:	Al Viro <viro@...iv.linux.org.uk>,
	Kamal Mostafa <kamal@...onical.com>
Subject: [PATCH 4.2.y-ckt 053/305] fix sysvfs symlinks

4.2.8-ckt2 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Al Viro <viro@...iv.linux.org.uk>

commit 0ebf7f10d67a70e120f365018f1c5fce9ddc567d upstream.

The thing got broken back in 2002 - sysvfs does *not* have inline
symlinks; even short ones have bodies stored in the first block
of file.  sysv_symlink() handles that correctly; unfortunately,
attempting to look an existing symlink up will end up confusing
them for inline symlinks, and interpret the block number containing
the body as the body itself.

Nobody has noticed until now, which says something about the level
of testing sysvfs gets ;-/

Signed-off-by: Al Viro <viro@...iv.linux.org.uk>
Signed-off-by: Kamal Mostafa <kamal@...onical.com>
---
 fs/sysv/inode.c | 11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/fs/sysv/inode.c b/fs/sysv/inode.c
index 590ad92..02fa1dc 100644
--- a/fs/sysv/inode.c
+++ b/fs/sysv/inode.c
@@ -162,15 +162,8 @@ void sysv_set_inode(struct inode *inode, dev_t rdev)
 		inode->i_fop = &sysv_dir_operations;
 		inode->i_mapping->a_ops = &sysv_aops;
 	} else if (S_ISLNK(inode->i_mode)) {
-		if (inode->i_blocks) {
-			inode->i_op = &sysv_symlink_inode_operations;
-			inode->i_mapping->a_ops = &sysv_aops;
-		} else {
-			inode->i_op = &simple_symlink_inode_operations;
-			inode->i_link = (char *)SYSV_I(inode)->i_data;
-			nd_terminate_link(inode->i_link, inode->i_size,
-				sizeof(SYSV_I(inode)->i_data) - 1);
-		}
+		inode->i_op = &sysv_symlink_inode_operations;
+		inode->i_mapping->a_ops = &sysv_aops;
 	} else
 		init_special_inode(inode, inode->i_mode, rdev);
 }
-- 
1.9.1