squashfs: add xattr id support

This patch adds support for mapping xattr ids (stored in inodes)
into the on-disk location of the xattrs themselves.

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>

1 files changed, 19 insertions, 3 deletions

diff --git a/fs/squashfs/super.c b/fs/squashfs/super.c
index 48b6f4a385a6..c4dfc393fa52 100644
--- a/fs/squashfs/super.c
+++ b/fs/squashfs/super.c
@@ -36,6 +36,7 @@
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/magic.h>
+#include <linux/xattr.h>
 
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"
@@ -82,7 +83,7 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent)
         long long root_inode;
         unsigned short flags;
         unsigned int fragments;
-        u64 lookup_table_start;
+        u64 lookup_table_start, xattr_id_table_start;
         int err;
 
         TRACE("Entered squashfs_fill_superblock\n");
@@ -143,7 +144,7 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent)
          * Check if there's xattrs in the filesystem.  These are not
          * supported in this version, so warn that they will be ignored.
          */
-        if (le64_to_cpu(sblk->xattr_table_start) != SQUASHFS_INVALID_BLK)
+        if (le64_to_cpu(sblk->xattr_id_table_start) != SQUASHFS_INVALID_BLK)
                 ERROR("Xattrs in filesystem, these will be ignored\n");
 
         /* Check the filesystem does not extend beyond the end of the
@@ -253,7 +254,7 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent)
 allocate_lookup_table:
         lookup_table_start = le64_to_cpu(sblk->lookup_table_start);
         if (lookup_table_start == SQUASHFS_INVALID_BLK)
-                goto allocate_root;
+                goto allocate_xattr_table;
 
         /* Allocate and read inode lookup table */
         msblk->inode_lookup_table = squashfs_read_inode_lookup_table(sb,
@@ -266,6 +267,19 @@ allocate_lookup_table:
 
         sb->s_export_op = &squashfs_export_ops;
 
+allocate_xattr_table:
+        xattr_id_table_start = le64_to_cpu(sblk->xattr_id_table_start);
+        if (xattr_id_table_start == SQUASHFS_INVALID_BLK)
+                goto allocate_root;
+
+        /* Allocate and read xattr id lookup table */
+        msblk->xattr_id_table = squashfs_read_xattr_id_table(sb,
+                xattr_id_table_start, &msblk->xattr_table, &msblk->xattr_ids);
+        if (IS_ERR(msblk->xattr_id_table)) {
+                err = PTR_ERR(msblk->xattr_id_table);
+                msblk->xattr_id_table = NULL;
+                goto failed_mount;
+        }
 allocate_root:
         root = new_inode(sb);
         if (!root) {
@@ -301,6 +315,7 @@ failed_mount:
         kfree(msblk->inode_lookup_table);
         kfree(msblk->fragment_index);
         kfree(msblk->id_table);
+        kfree(msblk->xattr_id_table);
         kfree(sb->s_fs_info);
         sb->s_fs_info = NULL;
         kfree(sblk);
@@ -355,6 +370,7 @@ static void squashfs_put_super(struct super_block *sb)
                 kfree(sbi->fragment_index);
                 kfree(sbi->meta_index);
                 kfree(sbi->inode_lookup_table);
+                kfree(sbi->xattr_id_table);
                 kfree(sb->s_fs_info);
                 sb->s_fs_info = NULL;
         }