lkml.org 
[lkml]   [2004]   [Apr]   [27]   [last100]   RSS Feed
Views: [more markup]  [less markup]  [headers]  [forward] 
 
Messages in this thread
/
DateMon, 26 Apr 2004 23:41:55 -0700 (PDT)
FromJunfeng Yang <>
Subject[CHECKER] warnings in fs/ext3/namei.c (2.4.19) where disk read errors get ignored, causing non-empty dir to be deleted
Hi,

We checked EXT3 filesystem on 2.4.19 recently and found 2 cases that look
like bugs.  For both of the cases, disk read errors are ignored, which
appears to cause a non-empty directory to be wrongly deleted or a dir to
contain more than one entries with identical names.

I'm not sure if they are real bugs or not, so your confirmations
/clarifications are appericated.

Please let me know if anything isn't clear

all warnings are in file fs/ext3/namei.c

----------------------------------------------------------------------------
[BUG] A non-empty dir may be deleted because ext3_read errors are ignored
by ext3_find_entry.  empty_dir is called whenenver ext3_rmdir tries to
remove a directory.

static int empty_dir (struct inode * inode)
{
			bh = ext3_bread (NULL, inode,
				offset >> EXT3_BLOCK_SIZE_BITS(sb), 0, &err);
			if (!bh) {
#if 0
				ext3_error (sb, "empty_dir",
				"directory #%lu contains a hole at offset %lu",
					inode->i_ino, offset);
#endif
				offset += sb->s_blocksize;
ERROR --->			continue;
			}
			de = (struct ext3_dir_entry_2 *) bh->b_data;
		}
----------------------------------------------------------------------------
[BUG] A dir may end up containing more than one entries with identical
names because because disk read errors are ignored by ext3_find_entry.
ext3_find_entry is called by lots of other ext3 functions (ext3_add_entry,
ext3_unlink, ext3_rename)
static struct buffer_head * ext3_find_entry (struct dentry *dentry,
					struct ext3_dir_entry_2 ** res_dir)
{
.....
		if ((bh = bh_use[ra_ptr++]) == NULL)
			goto next;
		wait_on_buffer(bh);
		if (!buffer_uptodate(bh)) {
			/* read error, skip block & hope for the best */
			brelse(bh);
ERROR --->		goto next;
		}



-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:02    [from the cache]
©2003-2008