udf: Preserve link count of system files

System files in UDF filesystem have link count 0. To not confuse VFS we
fudge the link count to be 1 when reading such inodes however we forget
to restore the link count of 0 when writing such inodes. Fix that.

CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>

diff --git a/fs/udf/inode.c b/fs/udf/inode.c
index 31965c3798f221ed7b81d3a37658fd1b9893609e..9ee269d3d5465242b7b68c31330e407c3ce8d262 100644 (file)
--- a/fs/udf/inode.c
+++ b/fs/udf/inode.c
@@ -1301,6 +1301,7 @@ reread:
                ret = -EIO;
                goto out;
        }
+       iinfo->i_hidden = hidden_inode;
        iinfo->i_unique = 0;
        iinfo->i_lenEAttr = 0;
        iinfo->i_lenExtents = 0;
@@ -1636,8 +1637,12 @@ static int udf_update_inode(struct inode *inode, int do_sync)
 
        if (S_ISDIR(inode->i_mode) && inode->i_nlink > 0)
                fe->fileLinkCount = cpu_to_le16(inode->i_nlink - 1);
-       else
-               fe->fileLinkCount = cpu_to_le16(inode->i_nlink);
+       else {
+               if (iinfo->i_hidden)
+                       fe->fileLinkCount = cpu_to_le16(0);
+               else
+                       fe->fileLinkCount = cpu_to_le16(inode->i_nlink);
+       }
 
        fe->informationLength = cpu_to_le64(inode->i_size);
 

diff --git a/fs/udf/super.c b/fs/udf/super.c
index 06eda8177b5f169625e07b7fc2d75c98830150c1..241b40e886b36b32fe11517adadd2a13565b21f0 100644 (file)
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -147,6 +147,7 @@ static struct inode *udf_alloc_inode(struct super_block *sb)
        ei->i_next_alloc_goal = 0;
        ei->i_strat4096 = 0;
        ei->i_streamdir = 0;
+       ei->i_hidden = 0;
        init_rwsem(&ei->i_data_sem);
        ei->cached_extent.lstart = -1;
        spin_lock_init(&ei->i_extent_cache_lock);

diff --git a/fs/udf/udf_i.h b/fs/udf/udf_i.h
index 06ff7006b822738ef73845b28fe68ae34f9890bf..312b7c9ef10e230df91bd03192b848181b6d8c5e 100644 (file)
--- a/fs/udf/udf_i.h
+++ b/fs/udf/udf_i.h
@@ -44,7 +44,8 @@ struct udf_inode_info {
        unsigned                i_use : 1;      /* unallocSpaceEntry */
        unsigned                i_strat4096 : 1;
        unsigned                i_streamdir : 1;
-       unsigned                reserved : 25;
+       unsigned                i_hidden : 1;   /* hidden system inode */
+       unsigned                reserved : 24;
        __u8                    *i_data;
        struct kernel_lb_addr   i_locStreamdir;
        __u64                   i_lenStreams;