[patch 1/3] dentry->d_count fixes

Maneesh Soni (maneesh@in.ibm.com)
Thu, 19 Jun 2003 18:40:13 +0530


- d_invalidate() can incorrectly return success instead of returning -EBUSY
as we can have situations where lockless d_lookup has found a dentry
successfully before d_invalidate drops it

fs/dcache.c | 3 +++
1 files changed, 3 insertions(+)

diff -puN fs/dcache.c~d_invalidate-fix fs/dcache.c
--- linux-2.5.72-mm2/fs/dcache.c~d_invalidate-fix 2003-06-19 17:34:38.000000000 +0530
+++ linux-2.5.72-mm2-maneesh/fs/dcache.c 2003-06-19 17:35:14.000000000 +0530
@@ -232,14 +232,17 @@ int d_invalidate(struct dentry * dentry)
* we might still populate it if it was a
* working directory or similar).
*/
+ spin_lock(&dentry->d_lock);
if (atomic_read(&dentry->d_count) > 1) {
if (dentry->d_inode && S_ISDIR(dentry->d_inode->i_mode)) {
+ spin_unlock(&dentry->d_lock);
spin_unlock(&dcache_lock);
return -EBUSY;
}
}

__d_drop(dentry);
+ spin_unlock(&dentry->d_lock);
spin_unlock(&dcache_lock);
return 0;
}

_

-- 
Maneesh Soni
IBM Linux Technology Center, 
IBM India Software Lab, Bangalore.
Phone: +91-80-5044999 email: maneesh@in.ibm.com
http://lse.sourceforge.net/
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