[GFS2] Shrink & rename di_depth

This patch forms a pair with the previous patch which shrunk
di_height. Like that patch di_depth is renamed i_depth and moved
into struct gfs2_inode directly. Also the field goes from 16 bits
to 8 bits since it is also limited to a max value which is rather
small (17 in this case). In addition we also now validate the field
against this maximum value when its read in.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 7 insertions, 4 deletions

diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index db5961a9aa59..65fdfee9ca9b 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -248,7 +248,7 @@ static int gfs2_dinode_in(struct gfs2_inode *ip, const void *buf)
 {
         struct gfs2_dinode_host *di = &ip->i_di;
         const struct gfs2_dinode *str = buf;
-        u16 height;
+        u16 height, depth;
 
         if (unlikely(ip->i_no_addr != be64_to_cpu(str->di_num.no_addr)))
                 goto corrupt;
@@ -293,7 +293,10 @@ static int gfs2_dinode_in(struct gfs2_inode *ip, const void *buf)
                 goto corrupt;
         ip->i_height = (u8)height;
 
-        di->di_depth = be16_to_cpu(str->di_depth);
+        depth = be16_to_cpu(str->di_depth);
+        if (unlikely(depth > GFS2_DIR_MAX_DEPTH))
+                goto corrupt;
+        ip->i_depth = (u8)depth;
         di->di_entries = be32_to_cpu(str->di_entries);
 
         di->di_eattr = be64_to_cpu(str->di_eattr);
@@ -1410,7 +1413,7 @@ void gfs2_dinode_out(const struct gfs2_inode *ip, void *buf)
         str->di_payload_format = cpu_to_be32(S_ISDIR(ip->i_inode.i_mode) &&
                                              !(ip->i_di.di_flags & GFS2_DIF_EXHASH) ?
                                              GFS2_FORMAT_DE : 0);
-        str->di_depth = cpu_to_be16(di->di_depth);
+        str->di_depth = cpu_to_be16(ip->i_depth);
         str->di_entries = cpu_to_be32(di->di_entries);
 
         str->di_eattr = cpu_to_be64(di->di_eattr);
@@ -1436,7 +1439,7 @@ void gfs2_dinode_print(const struct gfs2_inode *ip)
                (unsigned long long)di->di_goal_data);
         printk(KERN_INFO "  di_flags = 0x%.8X\n", di->di_flags);
         printk(KERN_INFO "  i_height = %u\n", ip->i_height);
-        printk(KERN_INFO "  di_depth = %u\n", di->di_depth);
+        printk(KERN_INFO "  i_depth = %u\n", ip->i_depth);
         printk(KERN_INFO "  di_entries = %u\n", di->di_entries);
         printk(KERN_INFO "  di_eattr = %llu\n",
                (unsigned long long)di->di_eattr);