[PATCH] Add a refcount check in dput()

Add a BUG_ON() to check for passing an unreferenced dentry to dput().

This is analogous to the similar check in dget(), and will make
reference-counting bugs in filesystems more immediately obvious. (I
just spent a while debugging an oops that turned out to be due to
broken fs reference counting.)

Signed-off-by: Paul Menage <[email protected]>

---
 fs/dcache.c |    1 +
 1 file changed, 1 insertion(+)

Index: container-2.6.23-rc3-mm1/fs/dcache.c
===================================================================
--- container-2.6.23-rc3-mm1.orig/fs/dcache.c
+++ container-2.6.23-rc3-mm1/fs/dcache.c
@@ -176,6 +176,7 @@ void dput(struct dentry *dentry)
 	if (!dentry)
 		return;
 
+	BUG_ON(!atomic_read(&dentry->d_count));
 repeat:
 	if (atomic_read(&dentry->d_count) == 1)
 		might_sleep();
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

---

• Follow-Ups:
  • Re: [PATCH] Add a refcount check in dput()
    • From: Andrew Morton <[email protected]>

• Prev by Date: Re: [RESEND][PATCH] dir_index: error out instead of BUG on corrupt hash dir limit
• Next by Date: Re: Distributed storage. Security attributes and ducumentation update.
• Previous by thread: Re: clockevents: fix resume logic
• Next by thread: Re: [PATCH] Add a refcount check in dput()
• Index(es):
  • Date
  • Thread

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]