Re: [PATCH] debugfs: properly set up extent header in do_write

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




Hi Eric,

Thank you very much, it worked well with your patch, I've tested it on
Fedora 18 x86_64, the kernel is 3.6.10-4.fc18.x86_64.

Tested-by: Robert Yang <liezhi.yang@xxxxxxxxxxxxx>

// Robert

On 07/24/2013 11:11 PM, Eric Sandeen wrote:
do_write doesn't fully set up the first extent header on a new
inode, so if we write a 0-length file, and don't write any data
to the new file, we end up creating something that looks corrupt
to kernelspace:

EXT4-fs error (device loop0): ext4_ext_check_inode:464: inode #12: comm ls: bad header/extent: invalid magic - magic 0, entries 0, max 0(0), depth 0(0)

Do something similar to ext4_ext_tree_init() here, and
fill out the first extent header upon creation to avoid this.

Reported-by: Robert Yang <liezhi.yang@xxxxxxxxxxxxx>
Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx>
---

diff --git a/debugfs/debugfs.c b/debugfs/debugfs.c
index dcf16e2..2660218 100644
--- a/debugfs/debugfs.c
+++ b/debugfs/debugfs.c
@@ -1677,8 +1677,19 @@ void do_write(int argc, char *argv[])
  	inode.i_links_count = 1;
  	inode.i_size = statbuf.st_size;
  	if (current_fs->super->s_feature_incompat &
-	    EXT3_FEATURE_INCOMPAT_EXTENTS)
+	    EXT3_FEATURE_INCOMPAT_EXTENTS) {
+		int i;
+		struct ext3_extent_header *eh;
+
+		eh = (struct ext3_extent_header *) &inode.i_block[0];
+		eh->eh_depth = 0;
+		eh->eh_entries = 0;
+		eh->eh_magic = EXT3_EXT_MAGIC;
+		i = (sizeof(inode.i_block) - sizeof(*eh)) /
+			sizeof(struct ext3_extent);
+		eh->eh_max = ext2fs_cpu_to_le16(i);
  		inode.i_flags |= EXT4_EXTENTS_FL;
+	}
  	if (debugfs_write_new_inode(newfile, &inode, argv[0])) {
  		close(fd);
  		return;



--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Reiser Filesystem Development]     [Ceph FS]     [Kernel Newbies]     [Security]     [Netfilter]     [Bugtraq]     [Linux FS]     [Yosemite National Park]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Device Mapper]     [Linux Media]

  Powered by Linux