[PATCH 21/26] NTFS 2.1.22 - Bug and race fixes and improved error handling.

From: Anton Altaparmakov
Date: Wed Nov 10 2004 - 10:18:12 EST


This is patch 21/26 in the series. It contains the following ChangeSet:

<aia21@xxxxxxxxxx> (04/11/05 1.2026.1.56)
NTFS: Fix bug in handling of bad inodes in fs/ntfs/namei.c::ntfs_lookup().

Signed-off-by: Anton Altaparmakov <aia21@xxxxxxxxxx>

Best regards,

Anton
--
Anton Altaparmakov <aia21 at cam.ac.uk> (replace at with @)
Unix Support, Computing Service, University of Cambridge, CB2 3QH, UK
Linux NTFS maintainer / IRC: #ntfs on irc.freenode.net
WWW: http://linux-ntfs.sf.net/, http://www-stu.christs.cam.ac.uk/~aia21/

===================================================================

diff -Nru a/fs/ntfs/ChangeLog b/fs/ntfs/ChangeLog
--- a/fs/ntfs/ChangeLog 2004-11-10 13:45:36 +00:00
+++ b/fs/ntfs/ChangeLog 2004-11-10 13:45:36 +00:00
@@ -83,6 +83,7 @@
the bug report.)
- Fix error handling in fs/ntfs/quota.c::ntfs_mark_quotas_out_of_date()
where we failed to release i_sem on the $Quota/$Q attribute inode.
+ - Fix bug in handling of bad inodes in fs/ntfs/namei.c::ntfs_lookup().

2.1.21 - Fix some races and bugs, rewrite mft write code, add mft allocator.

diff -Nru a/fs/ntfs/namei.c b/fs/ntfs/namei.c
--- a/fs/ntfs/namei.c 2004-11-10 13:45:36 +00:00
+++ b/fs/ntfs/namei.c 2004-11-10 13:45:36 +00:00
@@ -127,15 +127,16 @@
dent_inode = ntfs_iget(vol->sb, dent_ino);
if (likely(!IS_ERR(dent_inode))) {
/* Consistency check. */
- if (MSEQNO(mref) == NTFS_I(dent_inode)->seq_no ||
+ if (is_bad_inode(dent_inode) || MSEQNO(mref) ==
+ NTFS_I(dent_inode)->seq_no ||
dent_ino == FILE_MFT) {
/* Perfect WIN32/POSIX match. -- Case 1. */
if (!name) {
- ntfs_debug("Done.");
+ ntfs_debug("Done. (Case 1.)");
return d_splice_alias(dent_inode, dent);
}
/*
- * We are too indented. Handle imperfect
+ * We are too indented. Handle imperfect
* matches and short file names further below.
*/
goto handle_name;
@@ -181,6 +182,7 @@

nls_name.name = NULL;
if (name->type != FILE_NAME_DOS) { /* Case 2. */
+ ntfs_debug("Case 2.");
nls_name.len = (unsigned)ntfs_ucstonls(vol,
(ntfschar*)&name->name, name->len,
(unsigned char**)&nls_name.name, 0);
@@ -188,6 +190,7 @@
} else /* if (name->type == FILE_NAME_DOS) */ { /* Case 3. */
FILE_NAME_ATTR *fn;

+ ntfs_debug("Case 3.");
kfree(name);

/* Find the WIN32 name corresponding to the matched DOS name. */
@@ -271,12 +274,17 @@
dput(real_dent);
else
new_dent = real_dent;
+ ntfs_debug("Done. (Created new dentry.)");
return new_dent;
}
kfree(nls_name.name);
/* Matching dentry exists, check if it is negative. */
if (real_dent->d_inode) {
- BUG_ON(real_dent->d_inode != dent_inode);
+ if (unlikely(real_dent->d_inode != dent_inode)) {
+ /* This can happen because bad inodes are unhashed. */
+ BUG_ON(!is_bad_inode(dent_inode));
+ BUG_ON(!is_bad_inode(real_dent->d_inode));
+ }
/*
* Already have the inode and the dentry attached, decrement
* the reference count to balance the ntfs_iget() we did
@@ -285,6 +293,7 @@
* about any NFS/disconnectedness issues here.
*/
iput(dent_inode);
+ ntfs_debug("Done. (Already had inode and dentry.)");
return real_dent;
}
/*
@@ -295,6 +304,7 @@
if (!S_ISDIR(dent_inode->i_mode)) {
/* Not a directory; everything is easy. */
d_instantiate(real_dent, dent_inode);
+ ntfs_debug("Done. (Already had negative file dentry.)");
return real_dent;
}
spin_lock(&dcache_lock);
@@ -308,6 +318,7 @@
real_dent->d_inode = dent_inode;
spin_unlock(&dcache_lock);
security_d_instantiate(real_dent, dent_inode);
+ ntfs_debug("Done. (Already had negative directory dentry.)");
return real_dent;
}
/*
@@ -327,6 +338,8 @@
/* Throw away real_dent. */
dput(real_dent);
/* Use new_dent as the actual dentry. */
+ ntfs_debug("Done. (Already had negative, disconnected directory "
+ "dentry.)");
return new_dent;

eio_err_out:
@@ -338,6 +351,7 @@
if (m)
unmap_mft_record(ni);
iput(dent_inode);
+ ntfs_error(vol->sb, "Failed, returning error code %i.", err);
return ERR_PTR(err);
}
}
-
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