ext4: Add a comprehensive block validity check to ext4_get_blocks()
To catch filesystem bugs or corruption which could lead to the
filesystem getting severly damaged, this patch adds a facility for
tracking all of the filesystem metadata blocks by contiguous regions
in a red-black tree. This allows quick searching of the tree to
locate extents which might overlap with filesystem metadata blocks.
This facility is also used by the multi-block allocator to assure that
it is not allocating blocks out of the system zone, as well as by the
routines used when reading indirect blocks and extents information
from disk to make sure their contents are valid.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index dc34ed3..600b7ad 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -568,6 +568,7 @@
struct ext4_super_block *es = sbi->s_es;
int i, err;
+ ext4_release_system_zone(sb);
ext4_mb_release(sb);
ext4_ext_release(sb);
ext4_xattr_put_super(sb);
@@ -1055,6 +1056,7 @@
Opt_ignore, Opt_barrier, Opt_nobarrier, Opt_err, Opt_resize,
Opt_usrquota, Opt_grpquota, Opt_i_version,
Opt_stripe, Opt_delalloc, Opt_nodelalloc,
+ Opt_block_validity, Opt_noblock_validity,
Opt_inode_readahead_blks, Opt_journal_ioprio
};
@@ -1114,6 +1116,8 @@
{Opt_resize, "resize"},
{Opt_delalloc, "delalloc"},
{Opt_nodelalloc, "nodelalloc"},
+ {Opt_block_validity, "block_validity"},
+ {Opt_noblock_validity, "noblock_validity"},
{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
{Opt_journal_ioprio, "journal_ioprio=%u"},
{Opt_auto_da_alloc, "auto_da_alloc=%u"},
@@ -1508,6 +1512,12 @@
case Opt_delalloc:
set_opt(sbi->s_mount_opt, DELALLOC);
break;
+ case Opt_block_validity:
+ set_opt(sbi->s_mount_opt, BLOCK_VALIDITY);
+ break;
+ case Opt_noblock_validity:
+ clear_opt(sbi->s_mount_opt, BLOCK_VALIDITY);
+ break;
case Opt_inode_readahead_blks:
if (match_int(&args[0], &option))
return 0;
@@ -2826,6 +2836,13 @@
} else if (test_opt(sb, DELALLOC))
printk(KERN_INFO "EXT4-fs: delayed allocation enabled\n");
+ err = ext4_setup_system_zone(sb);
+ if (err) {
+ printk(KERN_ERR "EXT4-fs: failed to initialize system "
+ "zone (%d)\n", err);
+ goto failed_mount4;
+ }
+
ext4_ext_init(sb);
err = ext4_mb_init(sb, needs_recovery);
if (err) {
@@ -2875,6 +2892,7 @@
failed_mount4:
printk(KERN_ERR "EXT4-fs (device %s): mount failed\n", sb->s_id);
+ ext4_release_system_zone(sb);
if (sbi->s_journal) {
jbd2_journal_destroy(sbi->s_journal);
sbi->s_journal = NULL;
@@ -3515,6 +3533,7 @@
sb->s_flags &= ~MS_RDONLY;
}
}
+ ext4_setup_system_zone(sb);
if (sbi->s_journal == NULL)
ext4_commit_super(sb, 1);
@@ -3927,13 +3946,16 @@
{
int err;
+ err = init_ext4_system_zone();
+ if (err)
+ return err;
ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
if (!ext4_kset)
- return -ENOMEM;
+ goto out4;
ext4_proc_root = proc_mkdir("fs/ext4", NULL);
err = init_ext4_mballoc();
if (err)
- return err;
+ goto out3;
err = init_ext4_xattr();
if (err)
@@ -3958,6 +3980,11 @@
exit_ext4_xattr();
out2:
exit_ext4_mballoc();
+out3:
+ remove_proc_entry("fs/ext4", NULL);
+ kset_unregister(ext4_kset);
+out4:
+ exit_ext4_system_zone();
return err;
}
@@ -3972,6 +3999,7 @@
exit_ext4_mballoc();
remove_proc_entry("fs/ext4", NULL);
kset_unregister(ext4_kset);
+ exit_ext4_system_zone();
}
MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");